Werner,
I am also working in evaluation of VOI for our process. The directive came
from up stairs and my first reaction was, what for? We are pretty simple
when it comes to SM: .031"pitch, one QFP per assy. And we are not having
problems with the paste printing process (that we know of!!)
I have identified the January article, but have not read it yet.
Got any ideas on how to quantify the 'non-effectiveness' of measuring paste
height? I know when I go back with the prices, that alone will cause a few
palpitations! I don't want to just say it is too expensive for our use. And
in our case, Yes, the paste height has been identified as a reliability
issue, but not by anyone who knows if it really is or not.
Richard Hamilton
Clemar Mfg. / Rain Bird
[log in to unmask]
> -----Original Message-----
> From: Werner Engelmaier [SMTP:[log in to unmask]]
> Sent: Monday, February 01, 1999 2:31 PM
> To: [log in to unmask]
> Subject: Re: [TN] Solder Paste volume Standards
>
> HI TJB1,
> How do you define 'optimum solder paste volume'?
> Do you believe that solder volume relates to reliability?
> As the article in SMT January 1999 points out, shadowing makes the
> determination of solder volume very tricky at best, and it really does not
> correlate with anything important. There certainly are no 'Solder Paste
> Volume
> Standards', and there should not be.
>
> Werner Engelmaier
> Engelmaier Associates, L.C.
> Electronic Packaging, Interconnection and Reliability Consulting
> 7 Jasmine Run
> Ormond Beach, FL 32174 USA
> Phone: 904-437-8747, Fax: 904-437-8737
> E-mail: [log in to unmask]
>
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