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Why delamination happens on PCBs?

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#64467

Why delamination happens on PCBs? | 13 June, 2011

Hi

I have seen some of our multilayer PCBs are having delamination issues even after baking them in the ovens. Does anybody faced this issue before? The problem occured after reflow process and wave solder process as well. The temp profiles are well checked and in correct settings.

Thanks in advance, Milroy

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aci

#64468

Why delamination happens on PCBs? | 13 June, 2011

Delamination almost always is caused by moisture in the PCB. You can try to keep some of the PCBs in a dry box after recieving them. You can also slowly heat them up to bake out moisture. If you are purchasing boards form overseas form a board house that does not have a controlled environment you might be getting boards in that are already comprimised. We can help with bare boards if you get to a point where you are throwing your hands up. www.americancircuits.com

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#64472

Why delamination happens on PCBs? | 13 June, 2011

We find it is a bigger issue in the summer when there is more humidity in the air even though our facility is air conditioned. We've also seen similar boards go through the same process and vendor A has problems and vendor B doesn't, so fabrication techniques are sure to be a factor. What is your bake time and temperature?

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#64474

Why delamination happens on PCBs? | 13 June, 2011

What are your Bake Requirements? As in temp, duration, etc...

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#64504

Why delamination happens on PCBs? | 16 June, 2011

Hi Milroy,

One thing to check is the FR4 Laminate being used - if this is a RoHs build is the correct FR4 being used by your manufacture.

What layer count of board are you seeing the delamination on?

Does you board shop Vacuum seal the packages with a descant pad and Hic cards.If not I would suggest. Make sure they have Hic cards in the packages - this will indicate moisture in the package.

Regards,

BoardHouse Mdupont@activepcb.com

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#64514

Why delamination happens on PCBs? | 20 June, 2011

What is the correct FR4 for RoHS? This PCB is a 4layer board. When we get the boards from the supplier they are properly packed in vaccum sealed bags without HIC card but there is desicant in side.

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#64522

Why delamination happens on PCBs? | 22 June, 2011

if its a RoHs Assembly they should be using an FR4 material designed with higher TD to handle higher Assembly temps.

370HR,IT158, IT180, 4000-29 just to name a few that would be suitable. Standard FR4 material is not designed to handle the higher assembly temps needed for LF assembly.

If these are lead free boards - I would request your supplier use Hic cards in each package. Just because there is a desiccant pad in there does not mean there is no moisture.

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