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From [log in to unmask] Mon Jul 14 13: |
21:47 1997 |
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by ipc.org (Smail3.1.28.1 #2)
id m0wnm0U-000BlMC; Mon, 14 Jul 97 09:21 CDT |
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>From willli Mon Jul 14 09: |
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Hi Arjun,
It seems that the amount of flux deposited or the evenness across the
board, is likely to be the causes for the solder-short as you have mentioned
that it is better with the foam fluxer.
Try using fax paper and paste it on a glass slide or wave-level gauge,
allow the waxy side of the fax paper to face against the spray. Turn off the
preheat & the wave and pass the glass thru' the machine. Check the uniformity
and also the coverage. It may due to the spray-fluxer stops spraying slightly
earlier before the board is completely travelled thru' the spray-head or
uneven application on the board.
The solder balls formation may due to insufficient pre-heat, or improper
wave-hgt adjustment..
Good Luck ..
Poh
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At 02:45 PM 7/11/97, [log in to unmask] wrote:
>
>
>
>
>
> Hello Fellow Internetters,
> I work for ERG telecommunications, in Perth, Australia.
> We have been seeing problems with the wave solder process,with two
> defect types ie. Bridging (approx 12%) and solder balling(Approx 2%).
> Bridging has the higher rate of the two problems.
> The location that the bridging problem occurs is mainly at the front
> of the boards as they pass the wave machine. Also bridging is mainly
> the trailing edge type but, there are instances when it bridges
> across the board..
> The machine that is used, has the capability of spray and foam
> fluxing. Alternating between these two fluxing types, I observed that
> the foam fluxing gives better results, in most cases at 0% defect
> rate. My concern with changing to foam fluxing is that the residual
> contamination left after such a process is high( i am yet to test some
> boards with a Ionic contamination tester). The flux that is used is
> halide free Multicore X32-10i.
>
> Does anyone have any suggestions to reduce such wave solder problems ?
>
> Regards
> Arjun Murthy
>
> [log in to unmask]
>
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