Gloria: Yes it is certainly possible the masking came off in the
manufacturing process.
However from your email it is unclear to me if you are referring to the
bare board manufacturing process or the assembly manufacturing process.
Irregardless it could come off in either one. 

At the fab level there are many things that can cause it but usually it
is improper surface preparation prior to the application of the
soldermask. The type of metallization it is applied over, cure cycle and
subsequent post soldermask processing that it is subjected to can also
have an affect on adhesion.

But it may not be the manufacturing process at all. Poorly packaged
boards can rub and scrape against each other in transit or storage. 

It can also show up in assembly after repeated thermal cycles and/or
poor handling.


	
Regards
	
Michael Barmuta
	
Staff Engineer
	
Fluke Corp.
	
Everett WA
	
425-446-6076
	


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Gloria Brown
Sent: Thursday, November 09, 2006 11:34 AM
To: [log in to unmask]
Subject: [TN] masking question

We recently received some raw boards from a vendor and we typically do
an
inspection sample when they are received.  It was not noticed during the
sample but was found later that there were some very small areas located
on
traces that the masking had flaked off.  Is it a possibility just for my
own
satisfaction that the masking could of flaked off during the
manufacturing
process.  We do a tape test on 1 piece when the boards arrive also both
on
masking and on gold contacts.  

 

Does the color of masking make a difference?  These were masked in
Black!

 

Any comments? 

 

Gloria 

phone 906-932-5970  ext. 26

[log in to unmask]

 


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