Throwing Power of Nickel Sulphamate plating solution

Hello, Jen. Of course you want to plate at the highest possible production rate. A point that Guillermo and James are implying, I think, is that everybody always wants to do that, so the plating lines & plating processes were already optimized to make that a primary goal.

So when you ask "What simple adjustments do I make to plate faster?" the answer is: "Sorry, that adjustment for maximum plating speed was already made fifty years ago".

Your best hope for faster plating is extreme agitation. But if the terminals are still in a strip, 'jet plating' might do what you wish. Good luck.

A. Jen,
What is the current density that you are applying on your part? As I know, for Nickel sulfamate bath, an increase in the additive ( stress reducer ) may allow you to increase your current density, hence , your plating thickness. Check the TDS of your additive.

Ed. note: We see that you have thanked the responders not only in words, but by offering your own helpful advice on other threads here, Jen. Welcome to the forum!

A. Sulfuric acid will damage your bath. Use sulfamic acid. Since you want performance, keep your pH as close to 4 as possible. 3.9 to 4.1 is more appropriate. For more speed, I would use 4.0 to no higher than 4.2
Jim

A. Jen

Recently we observed that replacing half of the nickel with an equal molar amount of NaCl, KCl, or MgCl2 will greatly increase the throwing power and not slow down the plating rate. This could be an attractive solution to getting the nickel thickness centered in the range.

A. I wish I had your problem. To be honest, if your machine is running at a set rate of speed, and your are achieving your sprec, and your numbers are near the low end of the spec, it sounds like you are doing your job great. With the cost of Nickel at this time, I would think that sticking to the low end of the spec as much as possible would be just fine, if not desirable. Good Luck, and keep doin what your doin!

A. Amperages considerably higher than 100 ASF are not all that unusual, in some cases up to 400 ASF. I have seen reports of electroforming record stampers at 600 ASF.

Increased agitation is the key, but you'll also want to make certain the bath chemistry is spot on, and run at the higher end on temperature, perhaps 140 °F.

A. Hello Tom, I agree with Mr Holmes that 100 ASF can be achieved. There are a few cautions though. Your thickness distribution will suffer if the bath you are using is not formulated for current density of 100 ASF or more. For example; your Ni metal and sulfamic acid should be at a level to handle those CDs. Vigorous solution agitation alone will help, but your plating thickness will vary across the part. Your supplier is correct in what they say. Your tech data sheet for the Ni bath gives you a current density range (ASF). There is a good reason for this range given. Good things come with time... Good Luck.

A. Hello again Tom, now that I see your bath make-up I think you can maintain 100 ASF as long as your solution agitation is adequate. I was working with a bath from a MA supplier a few years back that had less of a Ni metal content, and was able to reach 120 ASF. I have also worked with Ni Sulphamate baths for printed circuit boards that we had to keep at 25 ASF. The important thing is being able to replenish fresh Ni ions at the cathode. An adequate Ni metal concentration along with good solution agitation aids in fresh ion transfer. Without it, you will experience poor thickness uniformity and possible discoloration or burning of the deposit. If you have a thickness measurement device, take thickness measurements on different areas of the part. This will tell you where you stand with the higher CDs. Good Luck to you.

A. Hi Tom,
That is a typical Ni sulfamate make up. The operating range for a standard sulfamate such as yours is 20-140 ASF (2-15 ADM). Remember, with increasing current density you in turn will have increasing internal stress in the deposit. Nearly all bath parameters will effect the amount of stress occurring during the dwell/growth period. Increasing temperature decreases Stress and increases hardness up to around 130 °F. I wouldn't recommend pushing the temp. much higher then 140 as many sulfamate hardeners and surface tension additives began to cook at or above 140 and create hard to remove contaminants. Contact your chemical supplier to be sure your bath can handle higher the recommended temperatures.


The literature here:
www.finishing.com/library/stein/stresspaper.html
... can be beneficial to you if you do run into problems with internal stress.