delamination test

What's the point of such a test? * If you are operating a board in an environment that keeps the board at a temperature that is close to causing delamination, why not design a board that can tolerate such an operating environment, rather than continuing to use a marginally specified board? * If your supplier cannot supply boards that do not delaminate, fix the supplier or find a new one.

Most analyze delamination by sectioning the board.

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PR,

A very basic test is to run bare boards through a reflow cycle. If delam is going to occur, in my experience, you have a >50% of seeing it in a single pass. The only time we do this is if we have a board off the line that has delaminated. We'll run a sample of boards through bare to confirm that we have a bad batch. Even if we see no failures on the bare boards, we'll reject the entire date code. Running the bare boards helps in making your case to the board house and management. I wouldn't run them through with a view of using them. I've seen them delam during the second pass on a double sided SMT board.

If you're running a lead-free profile in your reflow, you should be spec'ing a high Tg, high CTE, high decomposition temp laminate. Merix's website has a bunch of info on lead-free compatible laminates. Regular FR4 (Tg 130C) won't cut it in many cases.

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Pr.

I agree with some of the above responses. if you are seeing Delam issues with incoming PCB's the following should be check.

1) Check the OEM Print to what Material they are calling out to be manufactured with.

2) If they are calling out for Standard FR4 but do not give the TG they are looking for, I hate to say this but assume the board house is using 130 Tg. due to its Cost. And they would still be suppling to Print. The OEM or Assembly house should be calling out What TG or what process the boards will be going through expecially if it is for Lead free assembly.

3) If they are calling out for Lead free assembly do not just focus on TG, Higher TG does not always mean that it will withstand the New Lead free Temps. You need to focus on T260 & T288 ratings, this will tell you how long the material can handle Temps of 260c & 288c.

Our Shop Uses as a Standard Material FR406 170 TG. Leaded assemblies. and IS410 180tg for Lead Free assembly. Both are products of ISOLA. We are also looking at Polyclad 370turbo HR.

Please feel free to contact me if you have any further questions.

Regards,

Mike Dupont Sales Manager Circuit Science, Inc. 763-559-9515 Tel 763-559-2569 Fax. miked@circuitscience.com www.circuitscience.com

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Who said anything about having a delamination problem. He only said his boss wanted to test for it. I bet there is a >50% chance his boss has heard of (or maybe even one time seen) delamination and wants to be sure they don't have that problem. His boss probably felt a need to specify a test and that was one he had heard of. Personally I would recomend find a way for the boss to suggest a peel test instead of the delamination test. It would be easier. But the boss would have to think of it, and reject the need to test for delamination in this day and age.

What bugs me most about becoming more cynical over the years is I end up still not being cynical enough.

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