Earl I am following this with a lot of interest and have picked up some
good ideas.
We have now started to get some good results --still not 100%
We found passing the boards more then 2-3 times thru the HASL was causing
other problems -ie attack on solder mask (lifting),SIR, pad lifting etc..
not to mention the waste of time and effort
what seems to help most was
1) improved the precleaning -by slowing the conveyor speed
2) Maintenance period on the Horizontal unit - required more often
3) Reduce the copper content in the solder pot
4) monitor flux viscosity and change more often
We are still on it -thanks to all the on the technet form
afri
On Tue, 1 Dec 1998 [log in to unmask] wrote:
> Werner,
>
> I have no problem being included as "others," but it seems, for all us others, we are coming closer
> together about this issue. I'm basing this on what you are now saying.
>
> As far as not stating "evidence," I did provide sources for it so it may be obtained and used more
> objectively. I never intended to be the source - just the messenger and long time user of the
> source's/message's content. If you have other objective evidence, state or you will be guilty of
> the same offense.
>
> At least, I want to thank you for continuing a brave struggle and for admitting one very important
> thing. If it don't solder the first time, why do it a second?
>
> Something I am very curious about and, obviously, have little knowledge of, is HASL solder coating
> thickness. I always was informed the process, because of the leveling characteristics no matter how
> many times repeated, didn't add more thickness as the process kept it relatively inconsistent.
>
> Also, I believe Afri should be more a part of this ongoing discussion. His original question was
> what? I belive it had to do with multiple passes through HASL and what negative affects might be
> encountered. I took this to mean not just solder wetting (at HASL) and effective solder joint
> formation, but initial quality and long term reliability of boards and solder joints. Afri, where
> are you?
>
> There is so much more you have stated not originally addressed either in the original question or
> your initial rebuttal. It all adds up to the need for a better understanding for/by all us
> "others."
>
> And on it goes?
>
> Earl Moon
>
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