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High Phosphorus Ni Plating

Understanding the advantages regarding High P Ni plating over Al, I recently came across a situation where the P content amounted to 42%. Typically the P % should range between 10 and 15%. Is there any potential problems with such a high P content? Thanks in advance for your help.

Nick Magnapera
- Wayne, NJ
2005

You may be co-depositing sodium orthophosphite, which is a waste by-product of the hypo. I can think of no other way to get such a high phos content in a commercial bath. This of course will be deleterious to your deposit.

Guillermo Marrufo
Monterrey, NL, Mexico
2005

The 10-15% is typically by weight. It sounds like your 42% may be by volume. Have you looked into that.

Rick Richardson, MSF
Dayton, Ohio
2005

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2005

EN coatings cannot contain more than about 15% P. Even electrolytic Ni-P can only contain about 18 or 20% P.

Ron Duncan [deceased]
- LaVergne, Tennessee
It is our sad duty to note Ron's passing on Dec. 15, 2006. A brief obituary opens Episode 13 of our Podcast.

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42% P ?!? How did you check it? Maybe you did a wrong calculation.
Please tell us the method and calculation so we can look into it.

Sara Michaeli
Tel-Aviv-Yafo, Israel
2005

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2006

Hi All,

Our current concern is on the effect of the eliminition of the posphorous plating over a copper material, or leadframe. All of our leadframes are plated with Ni + NiP. Recent customer complaints on our products revealed that we have a problem on the plating itself. We are working full time on the Pure Ni plating leadframe qualification(without the NiP) but we found severe package delamination (taken through CSAM) as against to the Ni+NiP (control) plated leadframe.

Not only this, we also encountered poor solder (SnAgSb soft solder) wetting when we only have 8%H2 and 92%N2 gas (also called as mixed gas) at our diebond process. The control have no problem at all with this condition. We resolved this problem by increasing the mixed gas to 14%H2.

My questions are:
1.0 What is basically the purpose of the Phosporous in the leadframe plating. Or its purpose in the combination NiNiP?
The P-thickness by the way is only at 0.127 to 0.5um. The overall plating thickness is only about 1.27 to 3.0um.

2.0 Other than increasing the H2 gas, how can we improve the wetting of the solder?

3.0 Are there any available related literature on this topic that you can share?

4.0 What are your challenges in the use of Pure Ni plating only and how did you resolve them?

Thank you very much for any response you can provide.

Jeff Dellosa
Semiconductors - Cabuyao, Philippines