Hi joe,
matching pads---as I said, I published this in SMI.
Werner
-----Original Message-----
From: Joe Fjelstad <[log in to unmask]>
To: [log in to unmask]
Sent: Fri, Sep 4, 2009 9:40 am
Subject: Re: [TN] BGA/LGA land shape versus assembly yield reliability
? Hi Werner
Thanks, that kind of fits with my instincts. Were they both sides the same or
did you see any results from mixed pad assemblies and do you think that the data
might ever make its way to light?
Thanks again
Very best,
Joe
BTW I had my first taste of Glenmorangie scotch (10 year old) the other evening.
I appreciate your choice.?
?
?
Werner Engelmaier /* wrote:?
> Hi Joe,?
>?
> In the '80's, we at Bell Labs tries round, and rectangular pads. The ATC
results showd a slight reliability advantage for solder joints resulting from
rectangular pads. I have a paper in SMI sometimes in the early '90's [Bell Labs
management would not let it be published at the time] with the data. The reason
for the rectangular pads , by the way, was smaller possible pitch.?
>?
> Werner?
>?
>?
> -----Original Message-----?
> From: Joe Fjelstad <[log in to unmask]>?
> To: [log in to unmask]
> Sent: Thu, Sep 3, 2009 8:10 pm?
> Subject: [TN] BGA/LGA land shape versus assembly yield reliability?
>?
>?
>?
>?
> Greetings folks.
>
> I did a quick check of the archives on the subject and drilled a dry well
> (maybe drilled in the wrong place?).
>
> That said, in design and lay out we all tend to match pad shapes on the
> board with their mates on the package (round hole - round peg , square hole -
> square peg)
>
> My question is has anyone looked at (or know of) round with square and
> vice versa and collected assembly efficacy/results and/or reliability data?
>
> Finite Element Modeling data would be of interest as well.
>
> Thanks in advance for any responses?
>
> Joe?
>
> Since its Friday in some place of the world (or soon will be) I was looking
> over the period table recently and afterwards was wondering if anyone had
> ever mentioned that this little forum has it very own element, TechNetium,
> the first man made element. (the upper case N is my suggestion for future
> spelling... ;-)
>?
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?
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