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July 1997

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Subject:
From:
Poh Kong Hui <[log in to unmask]>
Date:
Tue, 1 Jul 1997 07:03:33 +0800 (SST)
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Hi Paresh Patel,

It seems that you are having outgassing from the board that result in
fine solder ball formation on the top side of the board.

Try baking the board. Hope that help..

Poh.

----------------------------------------------------------------------------
------


At 10:23 AM 6/30/97 -0500, you wrote:
>     Good morning everyone,
>     Lately, we are experiencing solder balls on the top side of single 
>     side PWB.  There are some holes that do not get any components before 
>     wave solder.  When the board hits wave, it makes "frying" noise and 
>     next thing you see is solder balls.  There are two bottom pre-heaters 
>     set at 450 F & 475 F.  Solder temp is 500 F.  Conveyor speed is  6 
>     fpm.
>     
>     This problem occurred in the past and was solved by increasing 
>     pre-heat temps.  which were originally 325 F & 350 F.  Now we are at 
>     the peak of  highest component heat ratings.  I checked several boards 
>     and made sure that there is no flux left on the bottom side before it 
>     hits solder wave. 
>     
>     Any suggestion on what should I try next will help.
>     
>     Thanks in advance,
>     Paresh Patel
>     Oneac Corp.
>     (847)816-6000 X-704

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