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Q&As since 1989


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Electroless nickel

2005

Right now we try to developed a new project electroless nickel on zinc diecast, our cycle is the following:
1.- Vapor degrease
2.- electrocleaning
3.- rinse
4.- acid dip with acid salt 30 gr/lt
5.- rinse
6.- Copper strike 42 gr/Lt Copper cyanide, 7.5 sodium cyanide, 15 gr/lt carbonate, temperature 45 to 50 °C ph 10.2 to 10.5, time 10 minutes
7.- Rinse
8.- Acid Copper
9.- Rinse
10.- Nickel woods 3 minutes
11.- Rinse
12.- Electroless nickel 30 minutes thicknes 2.5 microns to 5 microns

My question is the follow in appearance the parts looks good but our customer put in the part an electrical component with a special resin, and then are baked at 220°C for 10 minutes, after this operation our parts present blistering on the surface.
Somebody know if my process is correct or need other step to avoid the blistering?

Gabriel Ramirez N
Proquipa S.A de C.V. - Toluca, Mexico

Use a razor to pick at a blister, then you will have a fair idea where the plating is separating. Let us know the results.

Peter Van de Luecht
- Melbourne, VIc, Australia
2005