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Cracking gold plating using 3 mm mandrel

2007

I have problem encountered on the plating which is crack Au after plating using a 3 mm mandrill to test. This problem is only in 1 product, I ran different product but no cracking occur after bend test using 3 mm mandril. The present action I did are as follows: 1.I try to set ASF level 7.5 Ams but the problem still occur.
2. Apply double carbon filtering but problem still exist.
3. Done dummy plating to get other contaminants, problem still exist.

Cesar Sosmeña
FPC circuit manufacturing for electronics industry - Cavite, Philippines

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Cesar,
Because you are seeing the problem only in one product, I would double check the area to be plated and lower the current density even more. At 1 tr. oz Au per gallon current density can be as low as 5 asf for rack plating. You also want to check the thickness of the gold to make sure you're not plating too thick a deposit. If this does not do the trick, have the gold bath checked for metallic impurities such as Ni, Fe, Cu, Zn, Pb. Your gold should plate out the proper hardness to withstand the bend test. If the bath is too high in one or more of these metallics, the deposit will be too hard and can cause cracking. I would not advise dummy plating gold. It is very expensive, and you can't plate out enough of the impurities to do any good. Good Luck!

Mark Baker
Process Engineer - Syracuse, New York
2007