This is the tin in the solder joints complaining (just as you would if you
were dragged into a very hot place then dragged out again, ands then twisted.





At 11:41 26/02/98 PST, you wrote:
>I would like to request for input / feedback on an interesting problem
>that we are seeing sporadically in our SMT line.
>
>Some of the PCBs, post component attach, when they are either in or
>are coming out of the reflow oven are making a "crackling" noise !  We
>have not identified any defects in the boards or the components yet
>and we are unsure what is causing the noise.  Sometimes, we are also
>hearing this noise when we take a board in our hands post SMT and try
>to warp it a little !  The boards are approx 5" x 12", have components
>on both sides (passives and some actives) and is not very densely
>populated.  Any suggestions on what could be the reason would be
>greatly appreciated !
>
>Thanks,-Koushik Banerjee-
>
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Nicholas Kane
Axion Australasia
Suite 3, 651 Canterbury Road
Surrey Hills
Victoria 3127 Australia
tel: 613 9899 3511    fax: 613 9899 3811

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