Jason,

I have seen this problem before when the mask is too thick and along with
the glue the chip is held off the pad too far and and solder will not
bridge the gap so you get a skip.  This is more likely to happen with non
HASl boards because the pads are flatter and not as high.

Ken Kirby
Speedline Technologies




 (Embedded
 image moved   Jason Smith <[log in to unmask]>
 to file:      10/05/99 10:54 AM
 pic15649.pcx)




To:   [log in to unmask]
cc:    (bcc: Kenneth Kirby/ElectrovertUS/Cookson)
Subject:  Re: [TN] solder skips




I'm in search of a little insight, if you will.  I'm witnessing random
solder
skips on the bottomside of my panels.  Everything is clean, but I've
switched
mask types from the glossy to the matte finish.  Why would that cause
random
solder skips on the small chips and resistors on the bottomside 805's and
603's?
I'm trying to put some technical reasoning behind just witnessing the
problem.

Jason Smith

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