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From: bauer@procase.UUCP (Jerry Bauer)
Newsgroups: sci.electronics
Subject: Surface-mount stuff
Keywords: Surface mount
Message-ID: <4115bc7f.14dd6@c>
Date: 26 Jan 89 00:55:00 GMT
Organization: proCASE Corporation, Santa Clara, CA
Lines: 35

If you don't like drilling holes in p.c.  boards, you might like this
trick. 

I have on occasion surface-mounted I.C.s to homebrew p.c.  boards. 
First, I bend the leads so they are coplanar (see fig 1, below), then I
place the part on a pre-tinned set of pads, and solder it in place. 


                                   _____
                                 _|     |_
                               _| |_____| |_
                   -----------------------------------
				figure 1.


This works, and beats all that drilling.  I've also done this with
resistors and capacitors, but they only take two holes each.  The real
benefits come when I surface-mount a 40-pin dip.  This doesn't always
save 40 holes; I usually need some of those signals on the other side. 

I haven't tried the hybrid, surface-mounting some pins and through-
mounting others; it seems too much a hack, even for me.  I may yet do
it, though. 


Note, if you are interested in saving space, the leads can be folded
UNDER the body of the I.C.  at the cost of eliminating that area for
routing traces.  In this case, the only practical way to solder the chip
is to pre-tin each pad, place the chip, and re-heat the solder.  It's
more trouble than it's worth, as I see it. 

-- 
JRBauer (Jerry) ...!tolerant!procase!bauer
                ...!hpda!procase!bauer
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