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PWB plating process questions  / inner layer separation

Hi, Good day, I am Brandy, a PCB qualifications engineer here at APC Philippines,
I do have 2 questions:

1. We have recently have some quality issues on inner layer separations, I would like to know what are the probable cause and solution for this defect.

2. another is, is it possible to have different throwing power on component and solder side of the PCB? either for Panel plating or pattern plating,

Thank you in advance for the answers.

Abraham "Brandy" Dimapilis
- Philippines
2007

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2007

Abraham,
Inner layer separation can be caused by a few things. Improper lamination press or cure cycles whether it be pressure, time, temperature. Other culprits include inadequate coverage of inner layer oxide, moisture not being removed in pre lam or post lam baking cycles. I have also experienced separation due to a bad batch of prepreg and / or laminate. Unfortunately, there is not just one definitive solution to your problem. Your laminate supplier should be in your shop reviewing your process. Routing out a few test coupons to view at cross - section directly after lamination post bake will help zero in on the problem.
To answer your second question, there are cathode (board) shielding and thieving techniques that can be employed on either side of the board with thieving dots placed strategically on the outer layer artwork. Anode placement and distance can be altered to control plating thickness. This is something you have to experiment with. Good Luck!

Mark Baker
Process Engineer - Syracuse, New York

how to troubleshoot the inner layer separation problem in whole process?

RAMALAKSHMANAN
- Bangalore
May 8, 2009