Wow, there are lots of answers to this problem.  We need to know more to give 
you adequate help.  Thickness of adhesive?  Copper weight? and other things.  

Press pads and press cycles are some ways to deal with flow.  Soft press pads 
can help, so can "bump cycles".  

Another way to cut the flow is to use two layers of adhesive.  Say you need one 
mil of adhesive for the design.  Use the needed polyimide thickness with half 
the adhesive tacked to a second half thickness of adhesive drilled at a larger 
hole size.  Like five mils larger.

Call next week after IPC if you want to discuss it with me.

Chuck Brummer, ACUSON
(818) 734-4930



______________________________ Reply Separator _________________________________
Subject: Adhesive Squeeze Out
Author:  [log in to unmask] at ccUnix
Date:    3/5/97 11:34 PM


I have a problem with adhesive squeeze out on single sided flex layer. 
My drilled hole size is .053" and I have squeeze out that is closing 
done the hole done to .043".  We have tried plasma etch to to get the 
acrlyic out of the hole, but because there is no through hole (only 
coverlayer access hole)  plasma is not working.  Is there a way to 
remove the adhesive from the pads without having to skive all of them.

My panel size is 12x18 and I 74 sheets plus many strips that were die 
cut from other panels...

Appreciate all who reply....

Thank You

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