Gold Immersion - Soft Joints

William: In answer to your questions:

1 "What do I do about a gold porosity problem?"

Get it fixed, before you go out of business!!! You�ve been yapping about it on the internet for three days now!!! Get a more on!!! I don�t understand your company�s problem resolution process, but I would expect some focal point for solving problems, like Quality Assurance, and would have the following to get the process started:

� A trouble reporting method, like a corrective action request. AND � A team oriented troubleshooting process, like a Material Review Board.

If you don�t have something like that, contact the buyer responsible for purchasing boards and work with him/her on developing an approach.

2 "How would I approach the board house to check for this?"

Again, I�m not sure how your company goes about stuff like this, but I expect it would go something like this:

� I wouldn�t contact the fab directly without release from Purchasing to do so, it�s a nice courtesy. They should be aware of the possibility that you�re going to trash their supplier and/or increase their costs. Odds are, Purchasing will make the first contact with the supplier and get back to you. � Next, Purchasing tells you the supplier will meet with you just after lunch, that�s 2 PM in purchasing agent time, to discuss the problem. � Purchasing and the supplier return from lunch, waddling noticeably. � Purchasing says "I�ll leave you two to get on with this." Which translates from purchasing agent speak to: "Phew, I could use a nap!!!! Bye now." � You take the supplier to the shop and do your A, B comparison thing with the boards. You know, "we took special care to use identical processes on these boards, one from supplier A and the other from supplier B. Yes, same storage, same board age, same paste, same reflow profile, same oven �bla, bla, bla. Now look, the components on board A pop right-off the board, yet the components on board B are firmly attached." And on and on. � Stand back and let the supplier to his/her thing. � Don�t let the slimy little jerk get his/her hands on the good board, because you�ll be killed. First, your other supplier will kill you and drop your company as a customer, and then you�ll have no suppliers, and then the buyer will kill you. � Tell your supplier you need a written root cause analysis and corrective action. And that�s it up to him/her to agree with Purchasing on the plan for that and how the defective product will be handled. � Return the supplier to Purchasing. Of course, knocking first.

3 Does the problem lie in the board house�s chemistry or process?

I don�t know (and what�s more I don�t care, although as you are, I am curious). The fab is responsible for providing boards that are built to spec, according to schedule. How they do that is their business and that�s why they get paid BIG BUCKS. But then again, their children do seem to have a strange far-away look in their eyes and they�re all bald. (Right EM?)

Answer me this:

1 You say, you "see perfect gold thickness." How do you know that? 2 You say, that you see "no phosphorous contamination in nickel bath or after completion of process." How do you know that?

One final note: As someone (I wish I could remember who it was, so I could give him proper credit) said (I�ve taken liberties with the paraphrase) recently: It�s not clear that the benefits of the planar surface of ENIG is worth the hassles of trying to solder to that surface.

Good luck

Dave F

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