Metal finishing Q&As since 1989

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Nickel Coating on C11000- ELECTROLYTIC TOUGH PITCH COPPER (ETP)

2006

Could you be so kind to answer my question?

We are facing some peeling off problems with NICKEL ELECTROPLATING on Heat Sinks made of the above material. I am talking about batches of few thousands, (80x60x3mm). These heat sinks are soldered later by REFLOW process (at around 250°C) and their working temperature at the end user, is between 70°C to 90°C.
I was told that the ELECTROLESS NICKEL process with low phosphorus deposits of 1-3% P, is much better, much more reliable and much more appropriate for our purpose.
Is this true ? Can you please explain in more detail how/why?
What should be the thickness of the nickel?
What is the economical aspect (pricing) of this recommended process vs. the old one (supposedly you are also recommending the electroless process!)
Thanks a lot,

Aaron Kidron
motion control - Petach Tikva, Israel

My guess is that the amount of brightener in the EN is more of a factor than the "P" content. Nickel passivates and can be tough to solder if it sets out in the open for a long time (weeks). Rinse extremely well after the last plating step, dry very well and store in a closed container. Some plastics can be bad and some paper can be very bad.

James Watts
- Navarre, Florida
2006