Stella you can't have coplanarity problem with a three legged device. So your problem lies in
other areas such as geometry of pad, solder volume, solderability, placement pressures and so
on.

Mike


----- Original Message -----
From: Stella Neyman <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, March 08, 2000 4:19 PM
Subject: [TN] Coplanarity


> Dear Technetts,
> I have one custom design three leg SMT component. Two side leads (which are
> pretty massive and one middle center post). These leads are designed to
> create butt joints.
> Drawing specifies 0.004" coplanarity for all three leads. We are using
> 0.007" stencil.
> Now $1,000 question. I am using my life line and asking audience to help me.
> It seems, that center post doesn't create good solder joint. There are
> cases, when it seats only 0.001" deep in the solder and may break easily.
> I cannot use more than 0.007" stencil due to other component packages.  I
> don't want to touch up each solder joint after reflow.
> What would you recommend? Please advise.
> Sincerely,
> Stella
>
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