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Reply To: | TechNet E-Mail Forum. |
Date: | Mon, 18 Oct 1999 18:07:20 -0700 |
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Have you considered dryfilm soldermask?
Tim Reeves
> ----------
> From: Jeff Hempton
> Sent: Monday, October 18, 1999 11:48 AM
> Subject: lpugged vias, or no plugged vias?
>
> Hey gang,
> In a previous life, we did not worry about plugging vias in
> reflow/reflow boards for vacuum pulldown, since we were lower volume,
> high mix military bds., and could afford the time at test to
> clamshell
> or overclamp (Technical test terms I learned recently from the test
> group guys...).
>
> We are no-clean, and high volume. We have Genrad inline testers,
> which
> work quickly with vacuum pull-down, and the test guys like it this
> way. And we have been playing with various methods of plugging test
> vias with printed solder paste, and all other vias with LPI, and
> either get flux-vs.-probe problems or HASL solder caught in the LPI
> via pockets that resurrect themselves as solder balls during reflow!
> We have one small 4" square board that has about 300 vias, and are
> having a-heck-of-a-time trying to find a good solution for this. Oh,
> and all via annular rings must be solder resist covered or conformal
> coat covered, due to extreme environmental uses.
>
> Can anyone out there share some insight into this issue.
> Thanx in advance for your collective insights!!!
>
> Jeff Hempton, Sr. SMD Mfg. Engineer
> United Technology Electronic Controls
> e-mail: [log in to unmask]
>
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