Steve,

    My money is on the dry film being the problem.  Until recently all of our pwbs were
dry film.  Our main vendor had always complained that they could get no adhesion
consistency, lot to lot, from their material supplier.  I rarely received any product
that exhibited this problem but that was because, at times, my vendor ate considerable
rework to get us good pwbs.

    If this problem is caused by your cleaning process, why did the replacement lot
show no signs of flaky solder mask?  If this is the same supplier that is sending you
the delams, I'd have to say this dog won't hunt.  Over the last 25 years I've have had
board vendors tell me that problems I was having were in my processes, when other
vendors product were going through the same processes without causing a ripple on the
pond.

Gary Camac

Stephen R. Gregory wrote:

> In a message dated 08/31/1999 8:32:46 AM Central Daylight Time,
> [log in to unmask] writes:
>
> >Mornin' Steve and Earl and  All -
> >
> >Reviewing the photo's Steve mentioned sort of puts this thing in a different
> >light -
> >
> >The delams look as if they have occurred INTERNAL to the circuit side cap
> >layer, raising the question of just exactly how did the fabricator lay them
> >up, and of what materials?
> >
> >Second, the boards have a deep amber color, not dark enough to suggest
> >polyimide, but dark enough to suggest that the laminate saw an extended heat
> >cycle during the fab cycle.
> >
> >One last item - different subject - Wave solder operators - IMHO the home
> >grown kind usually work out better - they have no biases and often have a
> >higher level of interest in getting the job done right.  Look for a bright
> >youngster with a high aptitude for mechanics and chemistry and you've usually
> >got  a good candidate.
> >
> >Yall have a fun day - Kelly
>
> Hi Kelly!
>
> Sorry I didn't call ya' earlier, but been busier than a one-armed paper
> hanger this mornin'. One of the things I was doing was interviewing a young
> gentleman with just the kind of qualities you said. Works as an auto-mechanic
> now, so he's got mechanical aptitude. One of the past three jobs he had was
> as a stable hand working with show horses...I know that don't have anything
> to do with chemistry, but at least he'll know how to deal with "horse-s**t"
> and how to keep from getting kicked...hehehe.
>
> Anyway, the picture I sent ya. That amber color was from me messing around
> with the color count of the picture. I wanted to reduce the file size to send
> to you, so I reduced the color count from 16-million to 64,000 and when you
> do that, Paintshop Pro will ask if you want the pixels changed to the next
> closest color, or error diffusion, and either way the resolution suffers
> somewhat. The original file would have been 3.8-megs...I didn't want you to
> have and sit and download that! You'd a been cussin' me for sure! Actually
> the board doesn't appear scorched at all. The "toasty" look it has is
> actually a copper plane in the board, and the FR-4 color is really pretty
> clear looking...I still can send ya' the big file if ya' want.
>
> I took some more pictures this morning of something else, if anybody wants to
> take a look and give an opinion. They have to do with that Dry-Film mask
> adhesion problem that I talked about earlier. I've got a picture of one board
> that has the mask flaked off, and one of a board that looks the way it's
> supposed to. The Fab house continues to say it's our cleaning process,
> because of the Kyzen Aquanox XJN that we use. The board that I took a picture
> of that looks good, came from the latest replacement lot that they sent us.
> It doesn't have any components mounted on it, but I ran it through the reflow
> and did a tape test...no mask came off. Then I ran it through the MCS-1000
> cleaner and did another tape test...no mask came off. The picture of the
> board that has the mask coming off has components mounted on it, and the mask
> has completely come off from every bit of copper...all the traces and the
> via's, both on the top and the bottom of the board. From what I understand,
> this problem has cost us over 30K...and the fab vendor still is sticking by
> their guns saying that it's us, not them...help!
>
> -Steve Gregory-
>
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