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From [log in to unmask] Tue Apr 29 09: |
41:26 1997 |
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[log in to unmask] wrote:
> Elizabeth:
>
> >From the limited data that you have provided, I would say that the
> problem
> here is that the flux has dried out prior to the wave or that the
> flux has
> not been applied at all in the areas that look bad.
>
> The solder pot temperature of 500?F is acceptable. The topside board
>
> temperature of 210? - 220?F also is within normal limits but, it is
> on the
> high side. I would suggest that your customer either turn up the
> conveyor
> speed or turn down the pre-heat to the extent that the topside
> temperature
> would be between 180? - 200?F. In addition, I would make sure the
> board is
> being adequately fluxed.
Bill,
>From my own experience i don't think that neither 210-220F or 180-200F
makes much difference in the bridging matter but the flux has a great
influence. I would check the mask and flux if they match and also if
there's any large amounts of oxides on the wave.
/Jan Merstrand
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