Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Board baking after washing machine

FRANKY

#18039

Board baking after washing machine | 30 October, 2001

I have question about board baking after in line washing machine then I would like to know some information that ; 1) Do we need board baking after in line washing machine? Both bare board and assembly borad normally we don't bake . 2)In case of need to bake ,Do you have any procedure or standard to practise ? 3) In case of don't need baking , How we confirm that the moisture from washing process will not absorb in PCB and cause of delamination problem when we run in reflow process? 4) Do you hv any method to test moisture in PCB for confirmation the quality of PCB before use in normal process?

reply »

ianchan

#18049

Board baking after washing machine | 1 November, 2001

we bake boards 80~120 deg-C @1hr, after in-line DI wash.

oven setting to 90 deg-C, as +/-5 deg-C, tolerance against door open/shut fluctuations = "temperature loss".

If anyone has evidenced procedure, that shows no need for baking, pray do share wif us folks, as that would be a very interesting topic to review together.

Thanks

reply »

KS Wong

#18050

Board baking after washing machine | 1 November, 2001

We didn't perform any misprint boards baking after wash but we dry it with air blow. This is because we used the board immediately in the SMT process. Moisture will entrapped in the board normally occurred after few hours from washing and then it may cause problem especially in the via holes during reflow. Baking is normally performed after >168hrs, 1week of storage and frequently applied for rework after testing.

reply »

#18071

Board baking after washing machine | 1 November, 2001

We don�t bake between routine washing between soldering cycles. We bake when we immediately go to test or box-build.

Certainly, it all depends on your process, materials, and boards. So, how did you determine that you needed to spend the money? If you used a reasonable process to determine that you needed to wash and nothing has changed, then you should stick with what works.

reply »

Michael Parker

#18080

Board baking after washing machine | 2 November, 2001

I have two cases where I must bake after DI wash. The moisture entrapment is specifically within microprocessor sockets. Without air gun blow out and baking, oxidation occurs that causes flaky contacts for the PGA. We will bake for 2-3 hours @ 60C. Otherwise I do not know of a need to bake while "in-process". Of course, all the rules apply to bake components (removing moisture entrapment) prior to assembly.

reply »

PCB equipment

SMT Machines