Well, there have been several related discussions on this, but I really would like to hear what people think about my original questions, if possible.
  1. Are any of these fixable?
  2. Would you try, or would you just let them go, or would you scrap them?
  3. Can someone interpret what IPC-A-600 means by:
  -The blister or delamination does not span more than 25% of the distance between adjacent conductive patterns.
  (adj patterns on the same layer as the delam, or adj patterns on any layer in the board or ...?)  For instance, dctest2.jpg spans the conductive patterns on the top layer, but the delam is on an internal layer (of course).
  Thank you.
  http://stevezeva.homestead.com/files/bigdelam1.JPG
http://stevezeva.homestead.com/files/dctest1.JPG
http://stevezeva.homestead.com/files/dctest2.JPG
http://stevezeva.homestead.com/files/mcx.JPG

----- Original Message -----
From: "pearl petras"
Sent: Monday, November 27, 2006 10:02 AM
Subject: [TN] More delam

> Arggghh,
> More delamination. Looks like poor quality PCB's - a simple quick test
> adjustment to a component seems to be causing a lot of boards to 'pop' in
> the same area. As well, others are popping in the area of a
> hand-installed edge connector, when they start to solder the center pin.
> Even just tinning the pad does it sometimes.
> What would you do with boards like this?
> Would you try to fix it? How?
> Would you scrap it? There are some very expensive IC's on this board.
> Do you think it may go deeper than one layer?
> It is a 10 layer PCB
> IPC-A-600 states:
> -The imperfection does not reduce the space between conductive patterns
> below the minimum conductor spacing. (OK - minimum conductor spacing for
> low voltage is ~0.1mm)
> -The blister or delamination does not span more than 25% of the distance
> between adjacent conductive patterns. (What does this mean? adj patterns
> on the same layer as the delam? or do you consider 3-D, if the conductive
> patterns are on a different layer but the bubble spans underneath them?)
> -There is no propagation as a result of thermal testing that replicates
> the manufacturing process. (would you try more hand-soldering, or would
> you try a reflow process, how would you mimic it?)
>
>
>
> Steve, could I trouble you to post another few pics?
>
> Thanks all.
>


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