Pulse plating caused silver plating problems

A. The recommended "windows" for setting pulse and periodic reverse are generally proprietary. It will vary with your bath chemistry also. If the power supply manufacturer cannot provide you with the information that you need, you bought it from the wrong manufacturer. I think that there has been a book published in the last 5 or so years that includes a number of possible starting points. A search of the net might find it for you. AESF (www.nasf.org) is one possibility. This site has a listing of many books and a link to amazon.com

A. One of the more common problems with cyanide baths is a loss of cyanide resulting is reduced efficiency. If your cyanide levels are correct, then check you have calculated the rectifier conditions correctly. It used to be a widely held belief that pulse plating increased the efficiency of electroplating - it DOES NOT, - this is controlled by Faraday's Laws. Some years ago, some pulse plating systems were falsely sold on the basis of improved efficiencies. Make sure you have calculated the correct number of coulombs you need. If you are using a reverse pulse, remember to take that into account when you are calculating the process parameters - the reverse pulse will strip silver off the workpiece. Also make sure you have the correct pulse cycle conditions, as localised electrolyte depletion will reduce plating efficiency. Pulse plating can also adversely affect the way additives behave, so you may have to watch for that as well.

A. Hi,

Dynatronix have a web site with frequently asked questions and answers.

A. You want to get the same outcome as before, so why don't you get back to your tried and true practice (old rectifier)? You said it was doing just as good.

A. Hi, Petri. The article will probably be available from www.namf.org, although you may need to buy the proceedings of the whole session rather than just the single paper. Good luck.

A. Hello Ado,
From what you are saying the spotted areas appear rather consistently on the part. If the remainder of the part is plating well, I would suspect this would be a cleaning issue or particulate matter. Before going into the silver bath do a water break test to make sure the cleaning process is in order. Also you want to make sure the solution is particulate free (suspended solids). Non Cyanide Silver salts don't dissolve as well as Silver Cyanide Salts, so you want to make sure the salts completely dissolve before you begin plating. Check the Quality of your filtration, change filters often. Hope this helps!