Everything else held equal-
High P reduces corrosion from IAu (awfully hot topic in 4-14), but also significantly reduces dissolution rate in Sn (solderability)
Ideally, one could run a benign IAu bath and keep P lower
ENi fractures in isolation (as opposed to a plethora of them) can cause catastrophic problems by transferring the stress concentration to the copper, leading to very fast copper fractures.
Chris Mahanna
Robisan Laboratory
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Tony Lentz
Sent: Monday, January 29, 2018 11:06 AM
To: [log in to unmask]
Subject: Re: [TN] Phosphorus content in Electroless Nickel
Hello Frank,
Most electroless nickel baths used in the ENIG process generate a mid-range phosphorous content. The phosphorous content is typically 5 - 9% by weight or more preferably 7 - 8% by weight in the plated nickel deposit. Each chemical supplier/manufacturer will recommend the ideal phosphorous content for their process. I recommend that you contact the major U.S. chemical suppliers of electroless nickel baths (MacDermid, Atotech, Dow Electronic Materials, Technic). They can give guidance on a good specification range for phosphorous.
Best regards,
Tony Lentz
Chemist/Field Application
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-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Frank Kimmey
Sent: Monday, January 29, 2018 8:45 AM
To: [log in to unmask]
Subject: [TN] Phosphorus content in Electroless Nickel
Hey FAB Guys (or Chemical types or anyone else who might help), What should the P content in the Electroless Nickel bath be?
I am concerned some of our suppliers are running to high.
This could be the cause of some Brittle Fracture failures I have been seeing.
What would you consider a good range for Phosphorus percentage in the Electroless Nickel bath?
Thanks,
FNK
Frank N Kimmey CID+
Electrical Engineer / PCB Design
VeriFone Inc
1400 W Stanford Ranch Road, Suite 200
Rocklin, CA 95765 USA
W: 1-916-625-1818
M: 1-916-833-9877
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