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ARE ARE ANY REASION IN DELAMINATION OF SMD (QFP)EXCEPT HUMIDITY

KYUNG SAM PARK

#3251

ARE ARE ANY REASION IN DELAMINATION OF SMD (QFP)EXCEPT HUMIDITY | 18 August, 2000

Hi. Smtguys I need help. The delamination of smd (QFP) occured when we checked with the SEM. This device have been excursed smt process after baking for 24 hour (125��) in oven. Are there any other reasion in SMD delamination except humidity. thanks in advance.

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Dason C

#3252

Re: ARE ARE ANY REASION IN DELAMINATION OF SMD (QFP)EXCEPT HUMIDITY | 21 August, 2000

Hi! I had experience with my customer complain about the delamination on BGA.

The first question, I will ask my customer how they removed the parts and de-cap (my customer is using de-cap instead of SEM, I prefer SEM). Most of the customer which I believed that they removed the component from the board directly without baking the whole assembly to remove the moisture on the MSD device.

I am not sure that how long of your board expose to the environment. If you removed the parts stay for a certain period, moisture will trap into the encapsulation. When you de-soldering, it may caused delamination.

If it is a QFP then you can just cut the lead without apply any heat.

Beside the humidity, the other possible is the material itself or your reflow profile.

Good Luck!

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#3253

Re: ARE ARE ANY REASION IN DELAMINATION OF SMD (QFP)EXCEPT HUMIDITY | 21 August, 2000

Kyung Sam Park: Sure, several causes of plastic QFP package delamination, other than humidity absorption, are:

* Corrosion on component leads * CTE mismatch between leads and package materials * Package material adhesion strength degradation

What kind of delamination are you seeing with your SEM? Can you throw some picture on-line, maybe on i-drive.com or some place like that?

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