I 2nd that. Also, if you know how the leads will be clinched, you can
extend the pad (and soldermask opening) the length of the clinch for
stronger solder joint (since holes aren't plated thru, it can help a lot).
Other things to consider: Think hard about using jumpers on ground and pwr
paths, etc., etc... CEM-1 is much less expensive and a good alternative to
FR4 for 1 sided, but low volume fabshops won't have it. If you're designing
for high volume, the shop can punch instead of drill and route... high
tooling charge up front but cheaper in the long run. Chances are the board
will be screened instead of photo-imaged, so .015 trace/space may be your
minimum - check with boardshop. Soldermask annular ring may need to be .01,
also because of screen process.
-Chris
==
What I have typically seen is a minimum 20 mil annular ring, but I have
always added copper chamfering or teardropping to add strength to the pad
for rework. The larger the copper area around the drill, the less chance
of
a pad lifting if the part has to be removed and replaced.
--
George Patrick
Tektronix, Inc.
Central Engineering, M/S 39-512
P.O. Box 500
Beaverton, OR 97077-0001
Phone: 503-627-5272 Fax: 503-627-5587 Page: 503-575-9587
http://www.tektronix.com http://www.aracnet.com/~gpatrick
It's my opinion, not Tektronix'
-----Original Message-----
From: Mike Clemente [mailto:[log in to unmask]]
Sent: Thursday, April 04, 2002 6:53 AM
To: [log in to unmask]
Subject: [DC] Single-sided PCB
Hi Everyone,
Does anyone have any guidelines for single-sided thru-hole PCB design?
I do know that the component holes are to be non-plated thru and the bottom
side component pads are to be made larger, but what percentage larger? Any
other special layout notes?
Thanks in advance,
Mike
Mike Clemente, C.I.D.
Sr. PCB Design Specialist
dZinit Applied Technologies
415 W. Golf Road, Suite 28
Arlington Heights, IL 60005
Tel: 847-545-8170
Fax: 847-545-8175
Email: [log in to unmask]
"This e-mail message is intended only for the use of the named
recipient(s).
The information contained therein may be confidential or privileged, and
its
disclosure or reproduction is strictly prohibited. If you are not the named
recipient, please return it immediately to its sender at the above address
and destroy it."
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