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Session Organizer & Chairman: Harry J. Litsch, CFE-SE, H.J. Litsch Consultants, Inc., Bethlehem, PA
1 p.m._The Reduction of Drag-out in Barrel & Rack Plating Plants in Combination with a New Improved Drying Technology
Andreas Mobius, LPW Anlagen GmbH, Neuss, Germany
This paper will describe new developments that reduce the drag-out field of barrel plating. Practical results will be reported with new barrels, barrel blow-out and rinse systems. A new pulse-blow-dryer will be discussed that works with reduced temperatures, has a short drying time and creates a stainless surface.
1:30 p.m._Improvement of Tribiological Properties Through Nitrocarburizing
Georg Wahl, Durkerrit GmbH Thermotechnik, Hanau, Germany & Sharon Alwart, Degussa Corp., Ridgefield Park, NJ
Nitrocarburizing has long been successful in improving the surface properties of parts. A new process has been developed to allow nitrocarburizing at a temperature low enough to treat the necessary metal parts. This paper will discuss the influence of the treating parameter on the tribological properties and fields of application, and it will give comparisons of cost.
2 p.m._Software Applications in Surface Finishing Education & Technology
T. Shiraki, K. Kaminaga & T. Sato, Shibaura Technical University, Tokyo, Japan
Popular high-performance and easily available software in mathematics and analog circuit simulation will be applied in surface finishing education and technology. Mathematics software can be used for physiochemical calculations in surface finishing and wastewater treatment. Software for analog circuit simulation can be used for simulating DC or pulse electroplating and AC coloring of anodized aluminum.
2:30 p.m._Durability of Warning Labels & Plates
A. Ohtsuka, K. Kaminaga & T. Sato, Shibaura Technical University, Shibaura, Minato-ku, Japan
The enactment of the Product Liability Law in Japan has made it extremely important that warning labels and plates be durable. This, in turn, has prompted the need for novel developments in surface finishing technology. A report will be presented analyzing the durability of current labels and plates, and it will introduce some new methods for their manufacture.
3 p.m._Keys to Improved Communication Skills for finishers
Julie Mitchell, Mitchell Communications, Cleveland, OH
Session Organizer & Chairman: Joelie Hill, Scientific Control Laboratories, Inc., Chicago, IL
1 p.m._Determination of Brightener Concentration in Non-cyanide Alkaline Zinc Plating Bath by Cyclic Voltammetric Srtipping Method
S. Rajendran, Dr. S. Bharathi, V.N. Loganathan, C. Krishna & K.R. Anandakumaran-Nair, Lucas-TVS, Madras, India
A new cyclic voltammetric stripping (CVS) method for analyzing the proprietary brightener concentration in a non-cyanide alkaline zinc plating bath will be discussed. Using this CVS technique, the effect of primary additives and brighteners, singly and in combination, on zinc plating rate was extensively studied. From the calibration curve, it is possible to quantitatively estimate the brightener concentration within 1% error. This method has been successfully applied to control the brightener concentration in non-cyanide zinc plating production baths.
1:30 p.m._Simultaneous Multi-Metal Analysis
E.C. Stortz, C.D. Zhou, J.D. Burghard, Z.H. Jin, E.J. Taylor & R.P. Renz, Faraday Technology, Inc., Dayton, OH
An electrochemical transducer based on anodic stripping voltammetry (ASV) and high surface area microelectrode technologies has been developed. This transducer will be used in the plating industry for process control and compliance verification. Specifically, an accurate, rapid, and simultaneous multi-metal analysis methodology for low metal concentration analysis has been created. Clarifier water, copper rinse water, and lead/tin rinse water from a commercial printed wiring board facility was analyzed to measure trace copper and lead concentration with the developed metal monitor. The results are comparable with the results from atomic adsorption spectrometry.
2 p.m._Metallization of Polypyrrole Part III: Electrodeposition of Silver
Maria Hepel & Cynthia Rice, SUNY College, Potsdam, NY
Conductivity of thin polypyrrole films can be substantially increased by incorporating silver particles into the polypyrrole matrix or by plating polypyrrole with a thin film of silver. In this paper, several factors that influence the micromorphology of silver deposits such as the pH, the deposition potential, additives [e.g., sodium potassium tartrate (SPT)], and the composition of substrate electrode will be investigated. Morphology of silver electrodeposit will be examined using scanning electron microscopy, and distribution of silver particles as in the polymer matrix will be confirmed by using energy dispersive spectroscopy (EDS) analysis.
2:30 p.m._Submersible Sensor Probes for In Situ Monitoring of Bath Composition in Metal Plating
Tadeusz Hepel, Miroslaw Hepel & Joseph Wiejak, ELCHEMA, Potsdam, NY
This paper will report on the development of new sensors that can be applied to in situ monitoring and control for industrial plating baths, emphasising the copper and chromium plating processes. A fully automatic bath composition control system has been developed and tested in an industrial plating plant. Based on submersible sensor probes, the system can operate in strongly corrosive environments, and its software creates a comprehensive database and reports the results. New sensors for laboratory and field testing of bath composition will also be discussed.
3 p.m._Control of Plating Solutions in the Automotive Industry by Stripping Voltammetry
P. Bratin, G. Chalyt, M. Pavlov, E. Izro & R. Guzman, ECI
Technology, Rutherford, NJ & G. Boiksa, McGean-Rohco, Inc., Cleveland, OH
Increasing requirements on quality, cost, and environmental issues in the automotive industry call for tighter control of electroplating solutions and a narrowing of the operation windows. This creates a demand for high-accuracy analytical tools capable of multi-component analysis of plating solutions. The CVS (cyclic voltammetry stripping ) method has become a leading technique for control of organic additives in copper, tin, and tin/lead electroplating solutions for the electronics industry. This presentation will discuss the capability of the CVS technique for analysis of zinc, and the nickel plating solutions used in the automotive industry.
3:30 p.m._Executive Summary
Mark Boivin, Enthone-OMI
Process control in the specialty chemical industry is comprised of many elements. Enthone-OMI has gained ISO 9000 certification in all of its major manufacturing sites worldwide. These systems control the activities from the supplier of raw materials through manufacturing personnel to quality assurance. A case study on the manufacture of an electroless nickel component will demonstrate the extent of level of control.
4 p.m._X-Ray Fluorescence_New Key to Highly Accurate Non-Destructive Coating Thickness Measurements for Industry
Dr. Nicholas Yanaki, CMI International, Elk Grove Village, IL
A treatise on X-ray fluorescence technology and its importance to the surface finishing and printed circuit board manufacturing industries will be presented. Details will be given about X-ray generation, shell lines and energy levels, characteristics of X-ray emission, X-ray tube operation, a unique tube cooling method, microfocus filament advantage, programmable collimator action, optimum target material, target surface erosion, advantages of tungsten vs. molybdenum target, and key advantages of beryllium vs. glass windows.
4:30 p.m._Distribution of Cr(VI) in Solutions of Acids
Prof. R. Sarmaitis, V. Dikinis, V. Rezaite & V. Stasiukaitis, Institute of Chemistry, Vilnius, Lithuania
The experimental dependence of the apparent constant of formation of polychromium particles K3 on pH was determined by the static ion chromatography method. The equilibrium forms of Cr(VI) particles were estimated in solutions of acids. the effect of the presence of substituted chromates on distribution of equilibrium forms of chromic acid was evaluated. The change of acidic properties of Cr(VI) solutions was calculated with introductions of anions of various acids into their composition.
Session Organizer & Chairman: Tim Denhof, Scientific Control Laboratories, Inc., Chicago, IL
1 p.m._Structure & Morphology of Three Types of Zinc Deposits from Cyanide, Zincate & Chloride Bath
S. Rajendran, V.N. Loganathan, S. Bharathi, C. Krishna & K.R. Anandakumaran-Nair, Lucas-TVS, Madras, India
The deposit microstructure and surface morphology of three zinc plating systems will be compared by conventional microscopy and scanning electron microscopy. Results show that the possible difference in the surface composition and morphology accounts for the lower corrosion resistance of chloride zinc. Also, the different composition of zinc deposits from these electrolytes result in the variations in thickness measurements by different techniques. The effect of brightener on the composition of the zinc depost will be explained.
1:30 p.m._On the Relationship Between Surface Morphology & the Kinetic Factors of Conversion Coating Formation
Dr. Mois Aroyo & Nicola Tzonev, Technical University, Sofia, Bulgaria
Because of their crystal structure and surface morphology, conversion coatings can serve as bases for paints, lacquers and plastics. Roughness measurement tests have been performed to reveal the relationship between the surface morphology of conversion coatings and the activation and concentration polarization of the cathodic reaction. The activation polarization is charged by applying low voltage sinusoidal polarization with a frequency between 50Hz to 10kHz. The limiting diffusion cathodic current is controlled by adding an agent with high hydronamic activity. This makes it possible to find such forming conditions that provide the best adhesive performance of conversion coatings.
2 p.m._Pre-pickling Effect on the Surface Appearance of Chromated Films
Yon-Kyun Song & Hyung-Joon Kim, Pohang Iron & Steel Co., Kyungbuk, Korea
In this study, the pre-pickling effect on the surface appearance of chromated film was identified by using SEM, SAM, XPS and 3-D surface roughness meters. The whiteness of Zn-electroplated and chromated sheets depends mainly on the chemical state of the Zn surface that has been electroplated. Zn oxide states such as ZnO or ZnO1-x make the surface darker, while a pure Zn state makes the surface brighter with pre-pickling. It will be argued that pre-pickling removes zinc oxide and makes for a pure Zn state.
2:30 p.m._Effects of Plating Variables on Thickness Distribution in Alkaline Non-Cyanide Zinc: A Designed Experiment
John Commander & Mark Chasse, Enthone-OMI, New Haven, CT
Ideally, bath parameters are optimized so that the best ratio of deposit thickness (1:1) of recesses to flat areas is achieved. In this paper, four variables that are expected to affect plating efficiency and distribution will be examined. These variables are zinc metal concentration, caustic soda concentration, temperature, and current density. A fractional factorial designed experiment will be used to determine the effects of the variables with three different commercially available processes.
3 p.m._Study of the Potassium Hydroxide Alkaline Non-cyanide Bath
Vijay Kansupada, Novamax Technologies, Inc., Atlanta, GA
This paper will describe a study of potassium hydroxide-based zinc electroplating bath from the standpoint of the appearance of the deposit; distribution; efficiency; and a comparison to conventional sodium hydroxide baths.
3:30 p.m._Morphological & Impedance Analysis of Zinc Electrocrystallization in a Chloride Solution
Jeong-Real Park & H.T. Kim, Pohang Iron and Steel Company, Chunnam, Korea
Impedance spectroscopic measurements of the electrogalvanizing on carbon steel in a quiescent zinc chloride solution as a function of the pH, the additive, and the current density were performed. SEM microscopic observations of the galvanized surface were carried out and correlated in order to better understand the electrogalvanizing mechanism. By the additive, low current density and high pH, the characteristic impedance of the reaction will reveal gradual development of inductive loops on a complex plane plot, because it is related to the nucleation-controlled growth of the zinc crystals.
4 p.m._A New Process for Plating Zincate Electrolytes
Chris Mayhew, W. Canning, Inc., Palatine, IL
A new process for electroplating zinc from a zincate-type electrolyte will be described. The outstanding features are an almost constant thickness over complex shapes combined with a high plating rate. Comparative performance data with conventional processes will be presented, and production experience in both rack and barrel installations will be described.
4:30 p.m._Influence of Surface Patterns of Substrates on the Appearance of Electrodeposits
Chong Ho Sonu, J.R. Lee & Y.K. Kim, Research Institute of Industrial Science & Technology, Pohang, Korea
Steel sheets as substrates for electrogalvanizing having different roughness patterns manufactured by two different texturing techniques, such as shot blasting (SB) and electro-discharge texturing (EDT) were produced. the effect of the surface pattern of substrate on the appearance of Zn and Zn-Ni alloy deposits was investigated in terms of glossiness. This paper will discuss the effect of surface patterns on the gloss of electrodeposits with surface morphologies and phase structures.
Session Organizer: Harry J. Litsch, CEF-SE, H.J. Litsch Consultants, Inc., Bethlehem, PA
Session Chairman: Dr. James Lindsay, General Motors Research Laboratory, Warren, MI
8 a.m._Using Quality Teams to Promote Productivity
Fred Mueller, Pottstown Plating Works, Inc., Philadelphia, PA
Both the ISO program and team building are being used to fuel the improvements in Pottstown Plating Works' many departments. This paper will report on the first six months of the company's progress toward self-certification.
8:30 a.m._ISO Implementation Project with Metal Finishers
Christine A. Branson, Industrial Technology Institute, Ann Arbor, MI
A report will be given on the progress of an ISO Environmental Management System implementation project that is currently underway. The project involves a group of metal finishers in an 18-month process, highlighting environmental technology options and ideal management practices for metal finishers. Information will be developed to assist companies in diagnosing performance as well as in identifying options and upgrades that can be used to improve performance within the ISO 14000 Environmental Management System requirements for continuous improvement.
9 a.m._How to Work for a "Jerk"
Tam Van Tran, Ionics, Inc., Watertown, MA
The workplace would be boring if there were no "jerks" around. The "Jerk" makes us think, makes us work harder and be stronger, provides unlimited entertainment topics, and makes us laugh. This presentation will help you spot and identify the "Jerk" so you can enjoy yourself and be successful in your career.
9:30 a.m._The Use of A.T.P for Quick Determination of Throwing Power
Yair Assaf, Bohak Plating Co., Ltd., Hollon, Israel
A.T.P. is a simple test panel that can be used at the plating tank or in a small beaker right in the lab. The throwing power can be obtained by comparing the plating thickness between the center of the back and the center of the front panels. This highly reliable ratio gives the throwing power, using the panel with a series of different pulses, and yields good results very quickly.
10 a.m._Panel Discussion on Practical Applications
Panelists: S.O. "Skip" Cassell, Ames Metal Products, Chicago, IL; Yair Assaf, Bohak Plating Co., Ltd., Hollon, Israel; Jack Berg, SERFILCO, Ltd., Northbrook, IL; Gene Horvath, Custom Master, Inc., Longwood, FL; Joseph Mazia, P.E., CMfgE, Mazia Tech-Com Services, Chevy Chase, MD
Session Organizer & Chairman: Ron Parkinson, NiDI, Toronto, Ontario, Canada
8 a.m._Nickel Electroplating Applications & Trends
Dr. George DiBari, International Nickel Inc., Saddle Brook, NJ
Nickel electroplating is one of the most versatile finishing processes available, having a broad spectrum of end-uses that encompass decorative, engineering and electroforming applications. Although the main focus of this talk is on those applications, economic, regulatory and quality assurance trends will also be described to provide an overview of the current status of nickel electroplating around the world.
8:30 a.m._Environmental Concerns in Nickel Plating
Dr. Gerald A. Crawford, consultant to the Nickel Development Institute on Environmental Affairs
Owners/managers of nickel plating operations should be aware of environmental issues in the workplace, including exposures of workers to nickel-containing materials and disposal of aqueous effluents and solid wastes containing residual concentrations of various nickel compounds. Workers can be exposed to nickel in various forms by breathing aerosols of soluble nickel salts suspended in the workplace air and by skin contact with nickel compounds in solid form or as aqueous solutions. This paper will summarize the health effects of nickel-containing materials, exposure limits, preventive measures; disposal of liquid and solid wastes; and risk assessment and management as the proper bases for regulation of the industry.
9 a.m._The STEP Test_Tool for Improved Performance
Dr. Donald Snyder, Atotech USA, Inc., Cleveland, OH
The STEP Test has developed into an excellent tool for research, development and application of nickel electroplating. Corrosion resistance, post-corrosion appearance and product quality have all benefitted from the use of this easy-to-apply test.
9:30 a.m._Methods to Improve the Corrosion Performance of Microporous Nickel-chromium Deposits.
Robert A. Tremmel, Enthone OMI, Warren, MI
During the last several years, microporous nickel-chromium coatings have been severely scrutinized by the automotive industry. Today, these coatings must be free of all surface defects, even after long-term exposure to both accelerated tests and real-life service. While proper control of all the multi-layer nickel deposits is important, blemish-free surfaces can only be obtained when the microdiscontinuity and the activity of the post nickel strike are properly achieved and maintained. Our research will indicate that the most important factor is the electrochemical potential of the strike deposit.
Session Organizer: Linda Mayer, Lucent Technologies, Murray Hill, NJ
Session Chairman: Dr. Joe Abys, Lucent Technologies, Murray Hill, NJ
8 a.m._Issues on the Reliability of PWBs Metallized by a Graphite-based Process
Michael Carano, Electrochemicals, Inc., Maple Plain, MN
Questions about the long-term reliability of printed wiring boards manufactured by direct metallization (DM) have arisen with a new wave of DM technologies. This paper will address those issues in detail. Performance data obtained from thermal cycling, thermal stress DELCO-testing, components rework simulation interconnect integrity, and plating adhesion, etc., will be presented. Process capability for small hole plating (blind and buried) and exotic materials will also be discussed. Sufficient background on the development of the patented process will be given, along with the environmental attributes of the system.
8:30 a.m._Solder Alternatives to HASL
James P. Langan, J.P. Langan & Associates, Inc., Red Bank, NJ
The high I/O interconnections required by recent innovations in component technology are causing electronic manufacturers to reappraise current assembly procedures. With ultra-fine pitch devices mandating flat pads and a precise volume of solder on each lead, the industry is now forced to seek alternatives to hot-air-solder-leveled PWBs. A uniform tin/lead surface finish affords definite advantages for tape-automated bonding and micro-ball-grid-array. This paper will detail various processes that can provide this finish. Equipment considerations will be outlined, as well as cost comparisons with other alternatives, viz., precious metals, OSPs.
9 a.m._An Alternative Surface Finish for SnPb Solders: Pure Tin
Y. Zhang & J.A. Abys, Lucent Technologies, Murray HIll, NJ
Electroplated pure tin, bright or matte, has been used in the electronic industry as an alternative for tin/lead finishes for its excellent solderability and corrosion resistance. Whisker formation, however, has often limited its application, especially in high density semiconductor packages. It will be demonstrated that a whisker-free elecroplated satin-bright tin finish can be obtained by combining a proprietary chemistry and a unique plating technology. The resulting finish has excellent ductility, solderability and a stable grain structure. The properties of the tin finish and the features of the plating process will be discussed.
9:30 a.m._Precision Plating of Tin/Lead Alloys for Flip Chip Mounting Technology
Dr. A. Gemmler & W. Leonhard, Fraunhofer Institute of Manufacturing & Automation; Dr. H. Richter & K. Ruess, Alcatel SEL Research Center, Stuttgart, Germany
The deposition of bumps is a prerequisite for flip chip attachment of bare dies. Bumping, which is mostly done on the ICs at wafer scale, can be performed by microplating, vapor deposition or mechanical methods. Within this work, a bumping process based on tin/lead alloy plating will be presented. The high quality deposition of both the eutectic and the lead-rich solder composition will be described, and all key issues covering the equipment, electrolyte, and process parameters will be discussed in detail.
10 a.m._Fountain Electroplating of Lead/Tin Solder for Semiconductor Flip Chip Applications
Tom Ritzdorf & Bob Batz, Semitool, Kalispell, MT
A study of lead/tin methane sulfonate plating baths has been conducted for the purpose of maximizing the plating rate for useful alloys onto silicon wafers in a fountain plating system. The best candidate bath was chosen from an initial characterization to more fully evaluate the plating characteristics and current density limits for plating solder bumps on silicon wafers for flip chip applications. The methodology used in this work consisted of a series of statistically designed experiments, with the purpose of determining the significant process variables and evaluating their effects on the electroplated structures.
Session Organizer: Rich Dorset, Enthone-OMI, Stratford, CT
8 a.m._Electroplating Copper from an "Electroless" Copper Plating Bath
Dr. S. Bharathi, S. Rajendran, V.N. Loganathan, C. Krishna & K.R. Anandakumaran Nair, Lucas-TVS, Padi, Madras, India
Cyanide-containing electrolyte is widely used as a strike bath or to build up thick copper on substrates like mild steel, aluminum, and zinc. Because of the highly poisonous and hazardous nature of cyanide, conscious effort is being made to develop a suitable non-cyanide formulation. This paper will describe the development of a non-cyanide alkaline copper plating bath from an alkaline tartrate solution with amine- and sulfur-containing additives. Also described will be the influence of various parameters like additive concentration, current density and surface preparation.
8:30 a.m._Electroless Nickel-Cobalt-Phosporous: A New Wear-Resistant Process
Mark W. Zitko, Enthone-OMI Inc., New Haven, CT
A new electroless nickel-cobalt-phosphorous plating process has been developed. It produces a wear- and corrosion-resistant hard deposit. Using a Design of Experiments (DOE), it was determined that any desired Ni-Co-P alloy can be achieved. Heat treatments were done on the various alloys to determine the highest hardness and the best wear resistance. The results of Taber and Falex Wear tests and corrosion studies will be discussed.
9 a.m._Electroless Nickel Coatings in Process Safety Management of Chlor-alkali Plants
Mary Mukhtarian, Robert Tracy & Jerry Evarts, Occidental Chemical Corporation, Dallas, TX
Corrosion rates of electroless nickel (EN) will be compared with several common alloys in 50% sodium hydroxide under reflux (143 _C) and with nickel alloy 200 under velocity. The results will show that low phosporous(LP) EN has lower corrosion rates than nickel alloy 200 and many other commonly used alloys. In addition, heat treatment of LP-EN dramatically improves its corrosion/erosion resistance. The data will show why many chlor-alkali producers experience a large improvement in the service life of equipment coated with EN.
9:30 a.m._Wear-resistant Electroless Nickel: Practical Applications
Glenn O. Mallory, Electroless Technologies Corporation, Los Angeles, CA; Dr. Gary Loar, McGean-Rohco, Inc., Cleveland, OH; & Roger Vojinov
A new, very hard electroless nickel that provides improved wear resistance was introduced in November 1995. As a continuation of that study, practical applications of this coating have been made. This presentation will review the coating (Deposit H) and offer data and observations from trials performed under actual operating conditions in the field. These data will confirm the wear characteristics of Deposit H that were previously reported from laboratory tests.
Session Organizer & Chairman: Linda Mayer, Lucent Technologies, Murray Hill, NJ
1 p.m._Electromigration of Metallic Coatings in Electronics
Simeon J. Krumbein, AMP Inc., Harrisburg, PA
A review of electromigration will be presented in terms of the phenomena that adversely affect the performance and reliability of electronic packages and components that contain metallic coatings. Included will be discussions of the characteristics of the main electromigration mechanisms and of the various factors that increase the susceptibility of such coatings to electromigration. The primary emphasis will be on electrolytically-controlled processes at near-ambient conditions.
1:30 p.m._Assessment of the Coatings of Precious Metals Using Sequential Electrochemical Reduction Apparatus
Peter Bratin, M. Pavlov, G. Chalyt, E. Izro & R. Gluzman, ECI Technology, East Rutherford, NJ
A new application of SERA method to assess the surface conditions of coatings of the precious metals will be presented. The effect of a substrate barrier layer on the surface conditions will be evaluated. Experimental results obtained from different types of products coated with precious metals will be discussed. The influence of the elevated temperatures and humidity on the coatings of precious metals will be shown.
2 p.m._Assessment & Methods of Gold Microhardness
Pamela A. Harper & Dr. I-yuan Wei, AMP, Inc., Harrisburg, PA
Currently, the 25 gram Knoop microhardness test is predominant in the microhardness testing of gold-plated specimens. Although the use of hardness results is becoming increasingly more important in the industry, there are several major problems that must be addressed. A small-scale round-robin study was conducted to determine the repeatability and reproducibility limits of the Knoop test on gold plate. Results from two types of samples will be reported: Pre-mounted, pre-indented, read-only coupons, and pre-mounted, indent and read coupons. In addition, several laboratory methods for preparing test specimens will be discussed.
2:30 p.m._Electrodeposition of Magnetoresistive Co-Cu(Sb) Multilayers
N. Lecis & P.L. Cavallotti, Dip.Chimica Fisica Appl. Politecnico di Milano, Milano, Italy
Electrodeposition is one of the simpler and cheaper processes available for the fabrication of thin metal films. Recent developments have made it possible to electrodeposit a wide range of nanostructurate materials, including many that exhibit giant magnetoresistance (GMR). Two techniques will be described that can be used to produce multilayers from plating baths: The dual bath technique and the single bath technique. The second is preferentially used because, by using a single electrolytic to deposit both components of a metal/metal superlattice, any contamination that could result from exposure to atmosphere during transport between electrolytes is avoided. A report will be given on the characterization of electrodeposited Co-Cu(Sb) multilayers grown in a single electrolyte based on CoSo4 and CuSO4.
3 p.m._Electroless Nickel & Immersion Gold for Microelectronic Packaging Devices
Masayuki Kiso, C. Uyemura Company, Ltd., Osaka, Japan
This paper will discuss the properties of electroless nickel and immersion gold when used on microelectric packaging devices such as P-BGA, C-BGA, CSP, and flip chip. Phosphorous electroless nickel is the preferred finish when combined with 0.2 - 0.7 Êm of immersion gold. The discussion will focus on: The uses of electroless nickel and immersion gold for isolated patterns; wire bonding and solderability characteristics of the deposits; and the percentage of P in the electroless nickel deposit and its influence upon the desired film properties.
3:30 p.m._Intrinsic Mechanism in Immersion Gold Plating
Keith Kwong Hon Wong, Srinivasa N. Reddy, IBM Microelectronic Division, Hopewell Junction, NY
Although immersion plating has been used extensively in industries, there are relatively few published studies on the reaction mechanism. The process is simple and cheap, but it can lead to porous and non-adherent deposits to the base metal if done improperly. This presentation will outline some of the electrochemical aspects of immersion gold plating, with emphasis on the material and surface nature of the base metals.
Session Organizer: Ron Parkinson, NiDI, Toronto, Ontario, Canada
Session Chairman: Bob Srinivasan, EPI Electrochemical Products, Inc., New Berlin, WI
1 p.m._Nickel Recovery for Duplex Plating Operations
Mike Sheedy, P.E., Prosep Technologies, Pickering, Ontario, Canada
When recovering nickel from duplex nickel plating rinsewaters, two things are important to consider: The purity level of the recovered salt that allows return to the semi-bright plating bath, and the need to overcome cathode/anode inefficiencies, which increase nickel concentration in the baths as plating continues. A unique ion exchange system that produces a pure, concentrated, pH-adjusted chloride/sulfate nickel salt will be described. Also, details concerning a membrane-protected insoluble anode to allow total recycling will be presented. Case study information pertaining to performance, operating details, and design considerations will be addressed.
1:30 p.m._Design Flexibility with Satin Nickel Plating
Gerd Schîngen, LPW Chemie GmbH, Neuss, Germany
This paper will outline the various satin nickel design features obtainable from a single nickel sulfate/nickel chloride plating system. In this system, three or more uniform, silk-matte, non-dazzling fine crystaline structures with varying degrees of brightness or smoothness can be produced by changing a single chemical additive. The system does not require thermal cycling. Also discussed will be the physical characteristics of the satin nickel deposit, a comparison of test results against those achieved through normal bright nickel plating, and the advantages that this system offers over other methods of satin nickel plating.
2 p.m._Plating of Automotive Aluminum Wheels
Douglas E. Lay, CEF, TASKEM, Inc., Cleveland, OH
Automotive designers are again incorporating bright trim to the interior and exterior of automobiles in an attempt to enhance the overall aesthetics. One area that has an immediate impact on aesthetics is the wheel, and automobiles are being marketed with aluminum wheels electroplated with nickel/chrome as standard equipment. This paper will address the aluminum preparation sequence and discuss the plating requirements, specifications and process steps required to provide a finish with superior corrosion and impact resistance, in addition to aesthetics.
2:30 p.m._Panel Discussion
Panelists: Dr. Gerald Crawford, Nickel Development Institute; Dr. George DiBari, INCO, Ltd.; Douglas Lay, CEF, TASKEM, Inc.; Gerd Schîngen, LPW Chemie GmbH; Mike Sheedy, P. Eng., Prosep Technologies; Dr. Donald Snyder, Atotech USA, Inc.; Roger Timmer, Lacks Industries, Inc.; & Robert Tremmel, Enthone-OMI.
Session Organizer & Chairman: Beldon Hutchinson, LDC, Inc., Cleveland, OH
1 p.m._Brush Plating Trivalent Chromium
B. Hutchinson & Z. Mathe, Liquid Development Company, Cleveland, OH
Of the various techniques available for depositing coatings, brush plating has certain advantages, such as localizing the deposition process and the ability to control the chemistry and operating conditions of the relatively small volumes of solution used. Data on the brush plating of trivalent chromium and its properties will be presented.
1:30 p.m._Brush Nickel Plating Railroad Axles
Jone M. Rodgers, Metallize Illinois, Inc., Vandalia, IL
The Association of American Railroads specification M-967-80 outlines the brush plating repairs for railroad axles. The specifications must be adhered to in every detail contained in this document. No other repairs or changes are permissible. The certification of job shops is stringent, and unannounced inspections are carried out by the AAR inspectors.
2 p.m._Brush Plating Mistakes Made & Corrections Taken
David Barclay Sr., Dalcan Services Limited, Burlington, Ontario, Canada
Combining human nature with a technical process like brush plating creates a fertile breeding ground for both human and chemical errors. Since its mid-century inception, brush plating has made great advancements through chemistry, metallurgy and power supply. Not surprisingly, the skill level of the human brush plating technician has had to improve as well. Problems and mistakes, such as improper choice of plated material or improper identification of base material, often plague the brush plating process. This paper will discuss these and other common mistakes and suggest what corrections can be made to complete a successful job.
2:30 p.m._The Use of Selective Plating in Aircraft Maintenance
Danny L. Martin, Erickson Air-Cane, Central Point, OR
The selective plating ("brush plating") process is both necessary and cost-effective in airframe and powerplant repairs. This process is ideal for plating small areas of extremely large parts, restoring worn, corroded, or over-machined parts back to size, and for minimizing disassembly and machining costs, to name a few. Often, component repair is limited by the operator's ability to employ the many repair procedures that are available. In this discussion, one aircraft and one engine will be considered in relation to the detailed procedures outlined by aircraft and engine manufacturers and the US military, as they pertain to the areas of repair where brush plating may be used.
3 p.m._Minimizing Hazardous Waste Generation in Brush Plating
W.R. Wachtler, P.E., WR Associates, Inc., Encinitas, CA
Reverse machining has lately become the major use of the brush plating process. For lighter repairs, chemicals were designed to evaporate at the rate that the metallics were used from the solution, generating only minimal waste. Used in heavier repair work, however, the solutions lose their controlled buildup capability before the carrier chemicals can evaporate. A significant amount of rinse water is used in this process, and the amount of hazardous waste generated exceeds the amount of spent solution to be disposed of. This paper will cover the new techniques available to segregate and minimize the hazardous waste generated by the process, which will, in turn, reduce the cost of that waste disposal.
3:30 p.m._Brush Plating_An Overview
Beldon Hutchinson, Liquid Development Co., Cleveland, OH
This paper will address the use of brush plating and how it can be used to reduce or eliminate hazardous waste during the preparation of various base materials_with or without chemicals. The discussion will also include how to use the brush plating electrolytes for their entire useful lives. It will define the terminology of brush plating and explain how it is used in this industry.
Session Organizer: David Barrack, NAMF, Reston, VA
Metals are one of the largest single production inputs for metal finishing operations. The prices paid for this input can vary, based on world market conditions. This "Outlook 1996" will examine the changing dynamics of the metals market from the perspective of the metal finishing industry. The Metals Market Outlook will provide information on anticipated changes in the markets for important non-ferrous metals and an overview of how metal finishing facilities, both large and small, can anticipate the market and make the most out of their strategic buying power.
Representatives from the major metals producers, important brokers and others will predict the state of the markets for 1996 and beyond.
Session Organizer & Chairman: Dr. Eric Brooman, Concurrent Technologies, Inc., Johnstown, PA
8 a.m._Overview of the Important Characteristics & Properties of Chromium Coatings
D.A. Schario, D.S. Viszlay & E.W. Brooman, Concurrent Technologies Corporation, Johnstown, PA
Hexavalent chromium coatings are used in a wide range of functional and decorative applications. Because of environmental regualtions, the use of plating baths containing hexavalent chromium is of concern. An overview will be provided of the reasons for change, and the current efforts to develop acceptable trivalent or alternative chromium coatings.
8:30 a.m._The Mechanisms of Chromium Plating
N.V. Mandich, HBM Engineering, Lansing, IL
Even though the electrochemical mechanism used during chromium plating has been around for 75 years, its use is still open for conjecture. The present status of the theory will be explained, and kinetic aspects and the role of alkyl sulfonic acid as a catalyst will be presented. A discussion on the complex chemistry of trivalent and hexavalent chromium compounds will also be included.
9 a.m._A Review of Decorative Trivalent Chromium Electroplating
Dr. D.L Snyder, Atotech USA, Inc., Cleveland OH
Over the last 20 years, trivalent chromium electroplating has proven to be an environmentally friendly and productive process when compared to hexavalent chromium plating. The factors contributing to this success will be discussed.
9:30 a.m._Trivalent Chromium Coatings Applied by Brush Plating
Beldon Hutchinson & Zoltan Mathe, Liquid Development Company, Cleveland, OH
Of the various techniques available for depositing coatings, brush plating has certain advantages, such as localizing the deposition process, and the ability to control the chemistry and operating conditions of the relatively small volumes of solution used. Data on the brush plating of trivalent chromium and its properties will be presented.
10 a.m._The Engineering Properties of Hard Trivalent Chromium Functional Deposits as Deposited from a New Bath
V.N. Kudryavtsev, E.G. Vinokurov & O.E. Azarko, Eaton Corporation, Milwaukee, WI
Hard chromium deposits are electrolytic and dependent on processing conditions. Trivalent chromium deposition is no different in this respect. Data will be presented on the influence of electrolytic conditions on the properties of trivalent chromium deposits from a new plating bath. Hydrogen, oxygen and carbon content of the deposits will be discussed, as well as internal stress, hardness, and wear resistance. Efforts to correlate conditions with properties will be discribed.
10:30 a.m._Functional Chromium Plating from a Trivalent Chromium Bath
R.P Renz, C.D. Zhou, E.J. Taylor, R.G. Marshall, E.C. Strotz & B. Grant, Faraday Technology, Inc., Dayton, OH
Trivalent chromium baths have numerous environmental heath advantages. To date, such baths have not been widely used because of the difficulty in obtaining thick deposits with appropriate properties. A novel process will be described that provides comparable thicknesses, high plating rates and current efficiencies, and equivalent hardnesses compared to conventional, hard chromium deposits.
Session Organizer: Linda Mayer, Lucent Technologies, Murray Hill, NJ
Session Chairman: James P. Langan, J.P. Langan & Associates, Inc., Red Bank, NJ
8 a.m._An Environmentally Friendly Method for Plating Semiconductor Components: Palladium Lead Frame Plating
R. Schetty, LeaRonal, Inc., Freeport, NY
Conventional plating of semiconductor components involves the use of hazardous, environmentally unsound chemicals such as cyanide and lead. In order to reduce the exposure of manufacturing personnel to such harmful elements and to restrict the release of these chemicals into the environment, an environmentally friendly alternative plating method is required. Palladium plating of lead frames is a viable method for electroplating semiconductor components without cyanides or Pb. The background, plating sequence, deposit characteristics, and practical implementation of this technology compared to conventional plating methods will be discussed in detail.
8:30 a.m._Application-specific Surface Finishing Technique for Leadframes
I. Kadija, J. Abys, C. Fan, F. Humeric & I. Boguslavsky, Lucent Technologies, Murray Hill, NJ
Leadframe fabrication, including the surface finishing, must meet a variety of functional capabilities. In addition to solderability and wirebonding, leadframes must be engineered to withstand trim-and-form operation and a corrosive environment, regardless of the substance quality. In this article, we will describe our new developments in the field of formability and corrosion protection of leadframe substrates.
9 a.m._A High Temperature Electrical Contact Finish for Automotive Applications
E.J. Kudrak, J.A. Abys & V.A. Chinchankar, Lucent Technologies, Murray Hill, NJ
An electroplated finish for use in high reliability electronic connectors has been developed. It can withstand 200 _C for more than 2000 hours with no measurable changes in contact resistance. Data will be presented for several common precious metal finishes, including two palladium-based finishes, shown to be extremely stable under these conditions. The contact resistance will be measured at dry circuit conditions according to ASTM B667-92, Standard Practice for Construction and use of a Probe for Measuring Electrical Contact Resistance, at 25, 50, 75 and 100 gram loads.
9:30 a.m._EMI-RFI Shielding with Direct-Plate Technology
Dr. Nayan Joshi & Dr. Hermann Middeke, Atotech USA, Inc., Somerset, NJ
The increasing importance of conductive coatings for EMI-RFI shielding has resulted from the greater use of plastics materials in electronic product design. Although electroless copper plating is functionally superior to and economically competitive with other coating methods, it employs a number of substances that are harmful to the environment. Heightened environmental awareness has prompted the development of an alternative process that produces dense, copper-rich, electrically-conductive film on the non-conductive substrates. It is compatible with most of the commonly used resin materials, and has shown good potential for the direct metallization of molded plastic parts, large bare laminates, fabrics, and also for selective metallization on the specifically molded polymer parts.
10 a.m._A New Palladium Plating System for Decorative Purposes
I. Boguslavsky, J.J. Maisano, J.A. Abys, B.F. Stacy & V.T. Eckert, Lucent Technologies, Murray Hill, NJ
A novel palladium plating system provides a low maintenance bath with high efficiency, neutral pH, and consistently plated specular and ductile deposits up to thicknesses of 10 microns. Deterioration of the deposit appearance over the lifetime of the bath depends on plating conditions, metallic and organic contaminants, and breakdown products of the bath components. The most important factor affecting the deposit appearance is the presence of decomposition products that are intrinsic to the bath chemistry. This paper will discuss the analytical control, operation and maintenance processes that were used to develop this long-lasting palladium plating chemistry for decorative purposes.
Session Organizer & Chairman: Dr. Fred P. Reinhard, EG&G Environmental, Inc., Bloomington, MN
8 a.m._Liquid Cleaners
Stephen F. Rudy, Frederick Gumm Chemical Company, Inc., Kearny, NJ
Liquid cleaners are environmentally safer alternatives to traditional cold, hydrocarbon and chlorinated solvents. There are some process modifications to consider with liquid cleaners, such as heating, cleaning application, time, and drying. By selecting the appropriate process chemistry, the cleaning effectiveness equals or surpasses that of solvents. Liquid cleaners are readily adaptable to soak, spray, or ultrasonic equipment. Field applications for liquid cleaners have increased, and the practical benefits of using them include operating cost savings, greater safety, easier handling, excellent process control, and reduced sludge generation.
8:30 a.m._Electroplating from Additive-free Baths
C.D. Zhou, R.P. Renz, E.J. Taylor, E.C. Stortz & B.J. Grant, Faraday Technology, Inc., Dayton, OH
Current state-of-the-art metal plating relies on baths containing proprietary additives. These additives affect the plating process to yield electrodeposits with the appropriate properties for thier given applications. Because the additives and their decomposition products adversely affect the rinse operation, the rinse water can not be recylcled to rinse operations. A new, additive-free bath allows the recovery and in-process recycle of rinse waters and plating baths, enabling closed-loop, environmentally conscious metal plating.
9 a.m._Trends in Waste Treatment in Electroplating in Japan
Dr. Tadao Hayashi, University of Osaka Prefecture, Japan
Recent recycling and recovery technologies in the Japanese electroplating industry will be discussed. Some of the various effluent treatment systems in Japan_closed, econoback and cartridge-type ion exchange recycle systems_will be mentioned in detail. On-line alarm systems in waste water treatment in plating jobshops will also be discussed.
9:30 a.m._International Shipment of Hazardous Waste Ban: Free Trade . . . NOT!
Dr. Paul Piplani, R.E.M., TTX Environmental, Sturgeon Bay, WI
The Basel Convention was created in 1989 in response to shipments of questionable unidentified hazardous waste shipments that were being sent from developed countries like the United States to poor countries like China, India, Bangladesh and Indonesia. The receiving countries were not aware of the contents of these waste shipments, or of the correct methods of handling or managing them. In late 1995, the 100 nations belonging to the Basel Convention voted to phase out the movement of wastes accross international borders by January 1998. This paper will outline the contents of the new amendment, and will focus on the issues pertaining to the "Not-in-my-backyard," as well as the self-suficiency principles.
10 a.m._European Chemical Regulations
Dr. Xavier Albert Ventura, LC Systeme Iberica, S.A., Barcelona, Spain
Human protection of the environment and the risks of chemical products will be discussed. International, national, regional and local regulations pertaining to areas such as the monitoring of means (products, manufacturing, etc.), the regulation of production (packaging, labeling, etc.), and the classification of substances will also be analyzed.
10:30 a.m._Health & Safety Program Integration
Philip A. Platcow, C.I.H., Sedgwick James, Boston, MA
On-going cutbacks many leave large companies with skeleton industrial hygiene and safety staffs, but smaller firms now have only a single individual or no full-time professional at all to maintain the health and safety integrity of a firm. This creates a liability risk potential that must be addressed. These firms are now relying on outside consultants and the concept of "health and safety program integration." This paper will explore these ideas and present the results of comparable companies.
11 a.m._The Cost-effective Use of Chemical Fixation to Remediate Soils Contaminated from Metal Processing Operations
Dr. David J. Leu, Clayton Environmental Consultants, Inc., Laguna Hills, CA
The remediation of soils contaminated from metal processing operations has traditionally been an expensive undertaking. Such cleanups have usually relied on the use of hazardous waste landfills to dispose of the contaminated soils. A lower cost approach, which also reduced the offsite, long-term liability exposure, is the use of chemical fixation. This way, the soil can be treated onsite, rendered nonhazardous, and reused as a clean backfill. If offsite disposal of chemically fixated soils is preferred, such soil can be sent to a nonhazardous landfill. Two case studies will be presented that will demonstrate the cost-effectiveness of chemical fixation.
Session Organizer & Chairman: Donald M. Mattox, Society of Vacuum Coaters
8 a.m._An Overview of PVD Processing & Applications
Donald M. Mattox, Society of Vacuum Coaters, Albuquerque, NM
Physical Vapor Deposition (PVD) processes are atomistic thin film deposition processes in which material vaporized from a source is transported in the form of a vapor through a vacuum or low pressure gaseous environment to the substrate where it condenses. PVD processes can be used to deposit single or multilayer films of elements and alloys. Compound materials can be deposited by the reaction of depositing material with the ambient gas environment or with a co-deposited material. This paper will review the basic technology and applications of the principal PVD processes of vacuum deposition, sputter deposition, and ion plating.
8:30 a.m._Physical Vapor Deposition Wear-resistant & Decorative Coatings
Mark Podob, Richter Precision, Inc., East Petersburg, PA
PVD is a group of coating processes used to apply functional hardcoatings and decorative thin films. The coatings have a low coefficient of friction, are chemically resistant, and can act as chemical and thermal barriers. Applied in either single or multiple layers, the coatings can be used in a variety of industries, and provide different benefits depending on the application. This presentation will describe the properties of the coatings and discuss their various functional and decorative applications.
9 a.m._Case Study: Lifetime Anti-tarnish Finish
S.K. McKenzie, Vapor Technologies, Inc., Boulder, CO; W. Thomasson, Weiser Lock & J. Kostura, Masco Corporation
This paper will review the development and launch of a lifetime anti-tarnish finish that has been recently introduced to the residential door lock market. This case study will compare Weiser Lock's testing results for some PVD coating processes with low temperature arc vapor deposition (LTAVD), as well as discuss critical issues of cleaning and PVD processes.
9:30 a.m._Wear & Corrosion-Resistant Decorative Hard Coatings in Large Volume PVD Units
T. Hurkmans & F. Hauzer, Hauzer Techno Coating Europe B.V., The Netherlands
The combined steered arc/unbalanced magnetron technology has proven to be valuable in hard coating. In high number, low temperature and cost-effective production volumes, there is a strong demand for high throughput in PVD deposition. Multiple cathodes can be connected by optimally shaping the vacuum chamber, and systems configured with the cathodes in large doors are available for easy maintenance access. Fast pump-down and reproducible process pressures are reached by a combination of turbo pumps and roughing pumps. Other features of this technology, including the use of individual cathode shutters, radiative heaters, and roll-in/roll-out turntables, will be discussed in this paper.
10 a.m._Functional & Decorative Coatings by Physical Vapor Deposition
Robert R. Aharonov, Multi-Arc, Inc., Rockaway, NJ
Applications of PVD coatings as complimentary/replacement alternatives to the coatings in the electroplating industry will be addressed in this paper. The principles of vapor deposited coatings will be briefly introduced, but focus will be on cathodic arc (CA) and unbalanced magnetron sputtering (UBM) coatings. Superior adhesion, high hardness, and the "green" nature of the vacuum processes make the coatings attractive to various application fields where electroplating has been traditional. Several successful applications will be presented.
10:30 a.m._PVD Chrome as a Replacement of Hexavalent Chrome
Dr. Brent Lee, Vacuum Plating Technology Corp., San Jose, CA
To date, vacuum-based technologies have only been able to deposit thin films. A novel process will be described that uses a PLC-controlled, cathodic arc plasma depostition process to provide decorative and functional chromium coatings. As an option, a coat of ZrN or tin on top of chrome can be used to enhance color and luster. Metallographic data, salt spray and Taber Abrasion test results will be discussed.
11 a.m._The Least You Should Know About Color
Greg Caskey, Lakeshore Physics & Analytics, Holland, MI
How do you know that your product's color is right? What should you keep in mind when comparing color of production parts with customer color standards? Why is color matching difficult? This talk will answer these and other questions about color, color matching, and the language used to qualify color. Other areas of focus will be light sources, colorants and pigments, surface texture, metamerism, and inspection methodology.
Session Organizer: David Barrack, NAMF, Reston, VA
This "Outlook 1996" seminar will feature representatives from National Environmental Strategies (NES). NES is a Washington, DC-based consulting firm that represents the surface finishing industry on environmental, regulatory and legislative matters. Seminar attendees will be briefed on the direction of environmental legislation and regulatory policies relative to all surface finishers and suppliers.
Election-year politics will also be discussed. Particular emphasis will be placed on the leading candidates' positions regarding environmental issues.
Session Organizer: Dr. Fred P. Reinhard, EG&G Environmental, Inc., Bloomington, MN
Session Chairman: Peter Gallerani, CEF, Integrated Technologies, Inc., Danville, VT
1 p.m._Selective Ion Exchange Resins in Effluent Polishing Systems
Philip Fatula, BAYER Corp., Pittsburgh, PA
Selective ion exchange resins have been successfully employed in the US to recover valuable metals from many metal-containing waste and wastewater streams. The commonly used chelating iminodiacetic acid-using resins, however, have not found widespread application in waste stream polishing systems. Historic data on the treatment quality and cost-effectiveness of these systems will be presented to demonstrate their applicability in the US market.
1:30 p.m._Use of a NASA-Developed Ion Exchange Material for Toxic Metal Removal from Electroplating Baths
M.J. Ginther, J.T. Folkers, O.M. Uy, Johns Hopkins University/APL, Laurel, MD; K. Street, NASA Lewis Research Center, Cleveland, OH; & J. Naumann Jr., A-1 Plating Company, Baltimore, MD
A new polymer developed by NASA has been used to significantly reduce toxic metals effluents from rinse baths. Originally developed as a battery separator for space application, the active ion exchange material is a polymer made from polyacrylic acid and polyvinyl alcohol and converted to the calcium form. Data will be presented on the absorption efficiencies of the ion exchange material for metals such as zinc, copper, cadmium and lead. The removal of these toxic metals with a portable ion exhange filtration system will be discussed, and estimates of the labor and city water savings incurred in the process will be presented.
2 p.m._Simultaneous Multi-Metal Recovery with a Proprietary Process
C.D. Zhou, E.C. Stortz, E.J. Taylor, R.P. Renz & T. Sousa
Faraday Technology, Inc., Dayton, OH
Industrial wastewater usually contains several heavy metals, the elecrochemical recovery of which promises to be a viable approach for metal recycle. Unfortunately, conventional electrochemical methods are not efficient in treating dilute wastewater, and metals with higher negative reduction potentials are difficult to recover. A process is being developed that will efficiently and simultaneously remove multiple metals regardless of different reduction potentials.
2:30 p.m._Achieving A Closed-loop System While Recycling Water & Cleaner
Greg Savage, Membrex, Inc., Fairfield, NJ
During the pre-treatment process, parts are cleaned by solvents or aqueous cleaners. By incorporating filtration techniques such as ultrafiltration, the aqueous cleaning system can become a closed-loop system by filtering out the solids and oils and reusing the water and cleaner. Filtering the wash water can also be accomplished using ultrafiltration. This paper will discuss the filtration options, pros and cons to each option, and tips on how to make sure a system will work.
3 p.m._Wastewater Recycling for Electronic Plating
Kuo-Ruey Huang & Shan-Nan Lee, ITRI Taiwan, Chiu-Kwei Huang & Jung-Chung Tsao, PHILIPS E.B.E.I., Taiwan
A new recycling system uses ion exchange technology to recycle 99 percent of rinsing water. The resulting water quality is superior to that of the current system. Details of the system's operation will be discussed, and the cost savings and return on investment attained while using it will be analyzed.
3:30 p.m._Hexavalent Chrome Emission Testing Program: Assisting Metal Finishers in Meeting the 1995 Chrome MACT Standard
Jim Hensley, Industrial Technology Institute, Ann Arbor, MI
A pilot prevention/demonstration project focusing on meeting the 1995 Chrome MACT standard for hard chrome plating shops was undertaken under a combined National Institute of Standards & Technology and EPA Common Sense Initiative in the metal finishing sector. Four small/medium shops are participating in a 3-phase project that will include baseline testing of chrome emissions, development and implementation of modifications and upgrades, and post-modification testing to document the effectiveness of the changes. Baseline testing results and peer-reviewed modifications and upgrades will be discussed.
Session Organizer & Chairman: Robert Mikkola, CEF, Martin Marietta Energy Systems, Oak Ridge, TN
8 a.m._Pulse Plating
Dr. Per Moller, Peter Torben Tang, M.Sc. & Dr. Peter Leisner, Technical University of Denmark, Lyngby, Denmark
This video presentation will give a general introduction to the pulse plating technique. Important theoretical principles such as capacitative effect, nucleation and mass transport will be discussed together with numerous practical examples of the influence of pulsed current on the electrodeposition of chromium, copper and nickel. Pulse plating of other metals, like silver and gold, will also be illustrated. The video will also include a discussion of pulse rectifiers.
8:30 a.m._Important Parameters & Applications for Nickel Electroplating
Peter T. Tang, M.Sc., Frank Fontenay, M.Sc. & Dr. Per Moller, Technical University of Denmark, Lyngby, Denmark
This presentation will concentrate on the important mechanical and chemical parameters of nickel electroforming. Electrolyte parameters such as current density, the use of pulse plating and additives, pH value and temperature will be examined with respect to mechanical properties such as internal stress, material distribution and hardness. Very different applications will be used to illustrate these important parameters.
9 a.m._Electrodeposition of Ni from a Sulfate Electrolyte Using Pulsed Current
Dr. Jean Rasmussen, Metal Pioneer Finishing, Green Bay, WI & Else Hansen, Danfoss, A/S, Nordborg, Denmark
The presentation will contain results from tests involving Ni deposition from a sulfamate bath using DC. and square-waved pulse currents at different electrolyte temperatures. The paper will report on the deposition rate, material distribution and current efficiency, and it will give a crystallographic analysis of the grain size, crystal orientation and internal stress.
9:30 a.m._The Use of Fractally-Designed Wave Forms in Electroforming
Jonathan S. Bullock, Roger L. Lawson & John R. Kilpatrick, Lockheed Martin Energy Systems, Oak Ridge, IN
Pulsed electrodeposition offers the potential for superior control of deposit properties because of additional control variables available. These additional variables, however, make the optimization of pulsed deposition processes challenging. One method for global optimization that may, for example, control surface irregularities on several size scales, uses a periodic reverse design based on a fractal time series. This incorporates deplating pulses of several lengths within one self-similar waveform. The creation of such waveforms, their properties, and thier use in a lead-plating process will be described. Speculation on the potential for further application of this method will be offered.
10 a.m._Electrodeposition & Magnetic Behavior of Co-Co Multilayered Thin Films Subject to Low-Temperature Annealing
Dr. David Lashmore & Susan Hua, Materials Innovation, West Lebanon, NH
The electrochemical deposition of cobalt-copper multilayers will be described and the dependence of their magnetoresistivity on layer thickness and deposition parameters will be presented. For a wide variety of layer thicknesses electrochemically produced, Co (Cu)-Cu thin polycrystalline layered alloys exhibit a giant magnetoresistivity (GMR). Annealing studies of Co-Cu multilayered thin films, deposited on various substrate mateials, show that there exists an unexpected enhancement of both the magnetoresistivity and the magnetic sensitivity. This behavior is correlated with a combination of grain growth and grain boundary diffusion. A break-up of the layered structure occurs, enabling a magnetostatic coupling contribution to the GMR behavior. We observe a quasilinear GMR response (low-sensitivity material) or a non-linear (high-sensitivity material), depending upon deposition parameters. The major deposition parameter affecting this behavior is mass transport. Substrate grain size, layer spacing and annealing history, however, also play an important role.
Session organized by the Society of Manufacturing Engineers
Session Chairman: Ken Kreeger, Nordson Corp., Amherst, OH
1 p.m._Powder Coatings_A Customer Analysis
Paul D. Lovett, P.D. Lovett & Company Management Associates, Allentown, PA
In contrast to the coatings industry overall, powder coating is an exciting growth segment of the market. Domestic sales of powder and related equipment are already apporaching $1 billion annually, and they exceed that amount in other parts of the world, particularly Europe. A good economy has stimulated conversions to powder coatings in recent years, but growth of this technology will be sustained, because it is founded on a basic restructuring of the coating market. Although competitive positioning has hurt profits for some, those who sustain and grow their businesses will be rewarded by a strong market position that will generate cash.
1:30 p.m._Powder Coating: A Comparison of the European & American Approaches
John P. Birch, John Birch Associates, Warwickshire, England
This paper will explain the differences between the American and the European powder coating industries and show how the gap between them is narrowing. It will also look at some reasons for the success of bonding metallic pigments to powder coatings and examine some typical applications.
2 p.m._Electrophoretic Lacquering
Chris Mayhew, W. Canning, Inc., Palatine, IL
An electrophoretic lacquering process of the cathodic type will be described. Deposition is from an aqueous disperson of a polyacrylate resin bearing amino and blocked isocyanate functionalities. The resin deposit can yield a durable coating with the excellent throwing power of this type of process. A particularly attractive feature is the ability to dye the uncured colorless resin deposit, enabling a range of colors to be produced from one lacquering stage. A method of operating the process to give virtually zero discharge of resin will be described.
2:30 p.m._Powder Clearcoats
Dr. Paul H. Pettit, Jr., PPG Industries, Inc., Strongsville, OH
Clearcoat technology is well-established for liquid coatings, and clearcoats are used by a large variety of industrial end-users, utilizing a broad range of coating technologies and chemistries, including acrylic, epoxy, polyester and urethanes. These are applied either as 100 percent solid liquid coatings, water-based or solvent-based finishes. The use of powder clears, including both optically clear, as well as color-tinted clears, has not yet been fully exploited, as a result of certain practical limitations of powder clears. As new powder technology is developed, expanding the existing chemistry and application technology base, powder clears will become more widely used in the industrial coatings markets.
3 p.m._Fundamentals of Pretreatment for Powder Coating Applications
Brad Gruss, Fremont Industries, Inc., Shakopee, MN
3:30 p.m._Spray Applications for Powder Coating
Ken Kreeger, Nordson Corp., Amherst, OH
Session Organizer & Chairman: Sue Packman, CEF, Hughes Research Laboratories, Malibu, CA
1 p.m._A Model of Copper Electrodeposition from Cyanide Electrolyte
David A. Dudek & Dr. Peter S. Fedkiw, North Carolina State University, Raleigh, NC
A theoretical model of copper deposition from cyanide electrolyte on a planar electrode was developed to provide a quantitative framework for investigating the deposition mechanism. The model describes mass transport by diffusion and migration of all complexes formed by cuprous and cyanide through a boundary layer near the electrode surface, and allows investigation of the effects that varying solution composition and electrode potential have on current density and the concentrations of species at the electrode surface. Also applied to chloride electrolyte as an alternative to cyanide, this model is part of a larger program that aims to find bath formulations that do not use cyanide yet yield current distributions of similar uniformity.
1:30 p.m._The Role of Macro- & Microthrowing Power in Metal Distribution on Small-scale Profiles & Discrete Cathode Areas
Dr. Sergei S. Kruglikov, Mendeleyev University of Chemical Technology & Dr. Elena S. Kruglikova, Institute of Metallurgy, Moscow, Russia
Small-scale profiles and discrete cathode areas (printing wiring boards, etc.) are typical cases where both macro- and microdistribution phenomena may contribute to current and metal distribution. A number of chromium and copper plating solutions with various combinations of high and low macrothrowing power and positive or negative leveling power will be studied, using profiled cathodes and discrete disc and strip cathodes on a flat nonconductive plane. Results will demonstrate the relationships between cathodes' geometry and macro- and microthrowing characteristics of plating solutions in actual distribution of the metal deposit over the cathode surface.
2 p.m._Optical Precision Electroforms
Dongqing Cao & Darrel E. Engelhaupt, University of Alabama in Huntsville, Huntsville, AL
The main difficulties in fabricating X-ray optics are that extremely smooth surface finish and precise surface shapes for efficient X-ray reflection and high resolution are required. In this research, we selected silicon carthide (SiC) and indium-tin-oxide (ITO) to form the smooth surface from which we obtained the electroform reapplicated surfaces. High quality mirrors can be obtained if the roughness generated during electroforming and mirror removal processes is reduced. The easier fabrication process makes this technique both attractive and applicable.
2:30 p.m._Dealloying Studies of Nickel Zinc Coating on Steel
H.W. Pickering, M. Stein & K.G. Well, Pennsylvania State University, University Park, PA
Zinc nickel alloys meet the criteria for dealloying, i.e., above a critical potential, a planar alloy surface becomes unstable and the oxidation reaction proceeds very fast under development of a highly roughened surface. In this study, current transients after potential jumps will be used to characterize the corrosion behavior of Zn-11.5wt % Ni coatings on steel. It can be concluded from the resulting measurements and subsequent metallorgraphic examination that Zn-11.5Ni alloys show a behavior typical for dealloying systems: There is a critical potential that separates a potential regime with high corrosion resistance from one in which the occurence of pits or cracks indicates high corrosion rates.
3 p.m._Nickel Electrodeposition from Methanesulfonic Acid-based Baths
V.N. Kudryavtsev, S.A. Makeimenko & I.S. Chernyshova, Mendeleyev University, Russia
A bath for deposition of stress-free nickel coatings based on methanesulfonic acid has been developed. The characteristics and properties of methanesulfonic acid nickel plating bath and coatings with similar properties will be compared. The influence of the bath's components, as well as electrolysis conditions of the range of allowable cathodic current densities, current efficiency, bath throwing power and properties of coatings (ductillity, internal stress, porosity), will be outlined. Factors that affect coating quality and mechanisms of cathodic process of nickel reduction will also be addressed.
3:30 p.m._Intelligent Optimization System for Source Reduction in Electroplating Plants
Dr. Y.L. Huang & K.Q. Luo, Wayne State University, Detroit, MI
Source reduction-oriented optimization focuses on identifying areas where waste is generated most, developing optimal operating modes, and reducing costs. This paper will describe a computer-aided process optimization tool for source reduction in electroplating plants. The tool is part of an intelligent decision support system that can accept plating process information, environmental expectation and cost limitations. Two plating processes will be optimized to prove the applicability of this tool and to demonstrate how a company can achieve environmental goals with the lowest possible cost.
Session Chairman: Bob Kappler, Dynatronix, Amery, WI
1 p.m._An Effect of Pulse Plating Frequency on the Hardness of Bright Copper Deposits
Dr. Mois Aroyo, Technical University & Dr. Dimitar Stoychev, Bulgarian Academy of Science, Sofia, Bulgaria
Modern technology for the electronic engraving of gravure rolls imposes specific hardness requirements for the electroforming bright copper foils_the high initial values must remain constant for a relatively long time. Hardness measurement has been performed on DC and pulse-deposited copper coatings. The results will prove the validity of using low-frequenmcy pulse plating with brighteners. This mechanism predicts the occurrence of the maximum harness values at a "limiting" frequency as a result of an optimal matching of the process rates of nuclear formation, brightener adsorption and incorporation into deposits.
1:30 p.m._Comparing Four Different Pulse Anodizing Processes on Extruded 6063 Aluminum
Anne Deacon Juhl, M.Sc., & Dr. Per Moller, Technical University of Denmark , Lyngby, Denmark
When anodizing 6063 aluminum, different pulse parameters can be used. Over the years, various pulse wave forms have been suggested. Some of them are squared pulse; others sinusoidal. The pulse time is another parameter that can vary from milliseconds to minutes. All of them are trying to improve the oxide layer one way or the other. In this paper, four different pulse waveforms will be compared to see the advantages as well as disadvantages. One of the interesting properties of the oxide layer is the throwing power. The experiments show that the throwing power of the oxide layer varies for the four different waveforms. Also, the corrosion resistance and the wear resistance of the waveforms are distinct from each other.
2-3:30 p.m._Demonstration of Pulse Plating Equipment
Session Organizer & Chairman: Dr. I-yuan Wei, AMP, Inc., Harrisburg, PA
8 a.m._Vapor Phase Corrosion Inhibitors
Cheryl Smith, Senson Corp., Ltd., Chandler, AZ
Today's vapor phase corrosion inhibiting technology represents a step forward in corrosion protection, enabling companies to clean and inhibit at the same time. Each step in the finishing process is a building block for the next. Neglecting or modifying just one of these steps will result in consequences during the processing of the material. This paper will investigate vapor phase corrosion inhibitors (VPCIs) in the forms of coatings, cleaners and emitters.
8:30 a.m._Effect of Resin & Additives for the Lubricant-Coated Steel Sheet
Chan-Sup Park & Yong-Gyun Jung, Research Institute of Industrial Science & Technology, Pohnag, Korea
Lubricating resin for zinc-coated steel sheets was developed for application at in-line. It is mainly composed of epoxy-g-acrylate copolymer, lubricant, colloidal silica, etc. This paper will investigate the effect of epoxy on acrylate ration, the kind and amount of lubricant, and the amount of colloidal silica on the resin. Its quality will be characterized by friction coefficient, anti-fingerprinting resistance, formability and corrosion resistance. Coating weight, baking temperature, and cooling method will also be taken into account when evaluating physical properties.
9 a.m._Improved Corrosion Resistance Obtained Through Replacement of Chromium with Nitrocarburizing
Georg Wahl, Durkerrit GmbH Thermotechnick, Hanau, Germany & Sharon Alwart, Degussa Corp., Ridgefield Park, NJ
When combined with post oxidation, nitrocarburizing has proved effective in overcoming corrosion problems. This thermochemical treatment for metal surfaces has replaced chrome plating, obtaining better results at lower economic and environmental costs. This paper will explore several international case studies where the corrosion resistance of automotive parts has been improved through this process.
9:30 a.m._Self-assembled Monolayers (SAM) as a Molecular Level Barrier for the Corrosion of Mild Steel
S. Bharathi, S. Rajendran, V.N. Loganathan, C. Krishna & K.R. Anhandakumaran-Nair, Lucas-TVS Limited, Padi, Madras, India
Molecular self-assembly of organo-sulfur compounds has now been widely used in a variety of areas, such as molecular electronics and nano materials. Recently, they have been tried to prevent the corrosion of copper. Corrosion inhibition by these organized mono-molecular assemblies on mild steel substrate will be discussed in this work. Influence of chain length, coverage and the nature of the tail group on the corrosion behavior of MS were also studied and the results will be presented.
10 a.m._Experiences from Field Corrosion Test of Zinc & Zinc Alloy Coatings
Dr. Per Moller & Dr. Peter Leisner, Technical University of Denmark, Lyngby, Denmark
A number of zinc and zinc alloy coatings have been corrosion tested in an accelerated field test where the test panels are placed in a coastal area and are periodically sprayed with sea water. The test included: Acid zinc, cyanide zinc, cyanide-free zinc, zinc-cobalt 0.8%, zinc-nickel 15%, tin-zinc 20%, and a proprietary zinc (hot dip). To test the sensitivity of the different zinc and zinc alloy coatings to galvanic corrosion panels in contact with aluminum, stainless steel, copper and brass were included in the test.
10:30 a.m._An Accelerated Electrolytic Corrosion Test for the CU-Ni-Cr Plating System on the Intricate Shape Details
Dr. Rustem A. Kaidrikov & Dr. Boris L. Juravelv, Kazan State Technological University, Kazan, Russia.
In light of the results of accelerated and atmospheric corrosion tests conducted in different conditions, a method has been proposed for corrosion resistance prediction for Cu-Ni-Cr coatings. Accelerated tests were performed by cyclic potentiostatic anodic dissolution. The growth of the corrosion spots in the coatings was estimated by the coulopotentiograms. A special electrochemical cell was constructed for testing intricate shape details. The digital results of control corrosion resistance Cu-Ni-Cr coatings can be used for statistical operation of technological processes.
11 a.m._Encasement: A Generic Approach for Corrosion Control in Industrial Facilities
John Stahl, Preferred Solutions, Inc., Cleveland, OH
Facility maintenance in plating, surfacing and finishing plants is difficult because of the use of corrosive materials, such as hydrochloric, sulfuric and nitric acids. The encasement approach deals with spray-applying one or more materials, without surface preparation, ranging from 5/8-in. to 6-in. thick. The finished surface is an unsaturated polyester resin commonly described as "fiberglass" resins well known for their excellent durability, chemical resistance and weatherability.
Session Organizer & Chairman: Myron Browning, CEF, Matrix Technologies, West Hills, CA
8 a.m._Effect of Additives on Zn-Ni Alloy Electrodeposition
Hyun-Tae Kim & Young-Sool Jin, Pohang Iron & Steel Company, Pohang-shi, Kyungbuk, Korea
Zn-Ni alloys were deposited in a chloride bath containing various additives to investigate the influence of their anomalous behavior on the electrodeposition. The effects of aliphatic alcohol, saccharin and tamol on the Zn-Ni alloy composition and morphology were also studied. The results will show that the Ni content of deposit was increased by alcohol and saccharin but decreased by tamol. Also, the structure of deposit was improved by adding tamol. The effects of process parameters such as current density, flow rate and temperature in the presence of the additives will also be discussed.
8:30 a.m._Performance Characteristics of Zinc Alloys
David Crotty & Robert Griffin, MacDermid, Inc., New Hudson, MI
Electroplated alloys of zinc with iron, cobalt or nickel are being used to improve the corrosion resistance of the coating compared with normal zinc coatings. Acidic and basic plating solutions are being used to deposit these alloy coatings, resulting in a wide array of choices for the electroplater and the parts designer. This paper will explore the characteristics of the plating baths used to deposit the zinc alloys and will describe the properties of the resulting deposits.
9 a.m._Cadmium Replacement Through Zinc Alloy Technology: A Customer-Supplier Joint Research Effort
Victor Waldman, Enthone-OMI Inc., Warren, MI & Mark Barnes, Amphenol Corp.
Automotive corrosion specifications drove the early development of zinc alloy plating with mil. spec. requirements for cadmium, fueling the second phase of zinc alloy research. Cadmium replacement through zinc alloy research encompasses many factors, such as a comparison of corrosion results for various finishes, costs associated with complying with current cadmium regulations vs. complying with zinc regulations, and plating costs associated with both zinc alloys and cadmium. Also important is the adaptation for commercial use of zinc alloy applications that were originally employed as cadmium alternative in mil. spec. requirements.
9:30 a.m._Alloy Alternatives to Hexavalent Chromium
Jeff Michael Szotek, Enthone-OMI Inc., Warren MI
Recent environmental regulations mandating extensive testing and equipment investments for hexavalent chromium electroplaters have generated much interest in alternative processes for decorative and functional purposes. Among the growing list of available technologies designed to replace electrolytic chromium are a variety of alloy electrodeposits. These alloy processes possess diverse physical and operational characteristics affecting their suitability to specific applications. Operation of several commercially available alloy alternatives to hexavalent and the resulting deposit properties will be described.
Session Organizers & Co-chairmen: Pat Scalera, CEF, Parker-Amchem, Madison Heights, MI & Lee C. Branch, Albright & Wilson Americas, Richmond, VA
8 a.m._Surface Finishing of Alluminum Alloy for Die Cast
M. Yokoyama, K. Kaminaga & T. Sato, Shibaura Technical University, Tokyo, Japan
A novel anodizing method has been developed where the alloy is treated in a zincate bath for depositing zinc on aluminum alloy, and the deposited zinc is heated in a furnace for diffusing zinc atoms in the aluminum alloy. The method has yielded good corrosion resistance. This new method and other popular procedures prevalent in Japan will be introduced in this paper.
8:30 a.m._Internet WWW Server, "Anodizers' Plaza"
K. Kaminaga & T. Sato, Shibaura Technical University, Tokyo, Japan
The authors have set up an information server called "Anodizers' Plaza" on the Internet as of August 1995. The program contains files titled "Anodizing News in Japan," "On-line Lectures," and "Links to Other WWW Servers." Anodizers from all over the world are participating in the on-line discussions. The "Links to Other WWW Servers" page provides useful links to other servers related to anodizing science and technology. A detailed report on the Anodizers' Plaza will be presented.
9 a.m._How to Use Casting for Surface Treatment (CAST) on Sand Cast Aluminum Alloys
Anne Deacon Juhl, M.Sc. & Dr. Per Moller, Technical University of Denmark, Lyngby; Dr. Leif Hojslet Christensen, Danish Technological Institute, Tastrup, Denmark; & Dr. Jean Rasmussen, Pioneer Metal Finishing, Green Bay, WI
It is more complicated to use CAST on sand-cast aluminum items than it is to use it on pressure die cast items. In this paper, CAST will be used on sand-cast aluminum items to look at the possibilities and the limitations of the process. The image processing method will also be discussed in detail.
9:30 a.m._Abrasive Wear-resistance of Pulse-anodized Aluminum Alloys
Dr. Jean Rasmussen, Pioneer Metal Finishing, Green Bay, WI
This presentation will contain results from abrasive wear tests on various anodized aluminum alloys. The alumina tested have been produced using conventional D/C at low temperatures and square waved pulses at elevated temperatures. Pulse conditions are in accordance with the Y-process. The discussion will also introduce initial, post-, and compensated wear in order to understand the test results. A new post-treatment process that results in a significant improvement in abrasive wear resistance will be described.
10 a.m._A Reverse Pulse Process for Electrodeposition of Aluminum
Dr. Wolfgang Fromberg & Sandy Donaldson, AlumiPlate, Inc., Coon Rapids, MN
This paper will describe in detail an innovative process for the electrodeposition of pure aluminum, as well as some of the properties that the pure, electrodeposited aluminum can offer. Some of the applications for the high-purity aluminum-plated surface will also be discussed, including marine, aerospace, industrial and automotive applications for purposes of corrosion resistance, cadmium replacement, anodizability, brazability, high temperature resistance and meeting high purity material needs.
10:30 a.m._Problem-solving Hints for Anodizing
Richard W. Mahn, Novamax Technologies (US), Inc., Atlanta, GA
There are many parameters that must be controlled to get good quality anodized parts off the anodizing line. Normally, a presentation would start at the beginning and talk in the direction of the work flow. With this presentation, however, we will start at the end of the line_the unracking area_because that is where the majority of problems are observed. When a load does come out of unacceptable quality, what can you do to determine what went wrong?
11 a.m._New Technologies for Coloring Anodized Aluminum
Dr. Xavier Albert Ventura, LC Systeme Iberica, S.A., Barcelona, Spain
The properties achieved by integral color anodizing of different aluminum alloys will be studied. In a two-stage anodizing procedure, the influence of alloy and solution composition, temperature and anodizing conditions will be considered. The changes in color parameters obtained with complex facing electrolytes will be explained along with other coloring methods.
Session Organizer: Sue Packman, CEF, Hughes Research Laboratories, Malibu, CA
Session Chairman: Dr. James Lindsay, General Motors Research Lab., Warren, MI
8 a.m._Effect of Bath Stabilizers on Porosity of Electroless Nickel Deposits
L. Das & D.-T. Chin, Dept. of Chemical Engineering, Clarkson University, Potsdam, NY
A study has been made of electroless nickel (EN) deposition on ferrous substrates in the presence of four bath stabilizers: Lead ion, iodate ion, mercaptobenzothiazole and maleic acid. Deposit morphology and spreading of EN to carbon inclusions in carbon steel and cast iron were examined with SEM/EDS analysis. The porosity of EN coatings was measured as a function of bath stabilizer concentrations. It was found that the stabilizers retarded the rate of EN deposition on carbon inclusions and increased the porosity of EN coatings. Maleic acid decreased the phosphorus content of EN coating.Sulfur and lead co-deposited in the presence of mercaptobenzothiazole and lead ion, respectively. This paper will summarize the results of these investigations.
8:30 a.m._The Effects of Electroplated Zn-Ni Alloys on Inhibition of Hydrogen Permeation
Prof. B.N. Popov, D.H. Coleman & Dr. R.E. White, Dept. of Chemical Engineering, University of South Carolina, Columbia, SC
Hydrogen surface coverage, exchange current density, absorption-adsorption reaction constant, and hydrogen recombination were estimated on bare iron and on zinc and nickel-zinc plated iron. Hydrogen evolution and permeation decreased with each successive zinc layer until finally reaching an average decrease of 93 percent and 96 percent, respectively, as compared with bare iron. It was found that the decrease in the permeation rate of hydrogen through the iron membrane was the result of: (1) The decrease of hydrogen discharge rate; and (2) the suppression of hydrogen absorption and adsorption on the deposited zinc layers. The kinetic parameters obtained from the model, along with the observation that permeation was decreased even when the cathodic current was the same (at a given cathodic potential), indicated that the decrease in permeation when zinc-nickel is plated compared to bare iron is the result of a decrease in the absorption of atomic hydrogen (shown by a decrease in absorption-adsorption constant "k"). The kinetic parameters obtained from the model, along with the observation that permeation was decreased even when the cathodic current was the same (at a given cathodic potential), indicated that the decrease in permeation when zinc-nickel is plated compared to bare iron is the result of a decrease in the absorption of atomic hydrogen.
9 a.m._Modeling the Zn-Ni Electrodeposition System_Electrode Reaction Kinetics Calculation
M. Ranasubramanian, S.N. Popova, B.N. Popov and Dr. R. E. White, Dept. of Chemical Engineering, University of South Carolina, Columbia, SC
A mathematical model for the electrodeposition of zinc-nickel alloys from sulfate solution was developed that takes into account the various species existing in the plating bath and the reaction kinetics occurring at the electrode surface. The composition of the different ionic species present in the solution was calculated by using the equilibrium constants, material balances and electroneutrality for different values of pH of the solution. An autocatalytic mechanism for the electrodeposition of zinc, which was suggested in the literature, and an adsorption-reduction mechanism for nickel were used in order to determine the composition of the resultant alloy as a function of the concentration of different species present in the solution and the deposition potential. This simple model predicts the composition of the electrodeposited Zn-Ni alloy and the partial currents of the individual electrode reactions occurring at different deposition conditions.
9:30 a.m._Continuous Electroplating onto a Moving Resistive Cathode
Huk Yuk Cheh & Lin Cai Cheh, Columbia University, New York, NY
The primary, secondary and tertiary current distributions were calculated for electroplating onto a continuously moving flat electrode with finite ohmic resistance. The effects of electrode resistance, electrolyte conductance, deposition kinetics, mass transfer, and cell geometry on the uniformity of the metal distribution will be discussed. Quantitative results on the deposit uniformity over a wide range of the geometrical factor and process parameters will be presented.
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