Yvon,

.010"-.012" over drill size is pushing the limit. .018" via (finished hole
size, plated, I am assuming) would probably be drilled with a .024" drill
bit, assuming a +/- .003" tolerance on finished hole size. .034" would then
be the pad size. The PWB supplier would definitley let you know if that was
a problem. That is why it is a good idea to involve suppliers in DFM
reviews.

JU


-----Original Message-----
From: Yvon Hache [mailto:[log in to unmask]]
Sent: Wednesday, February 02, 2000 8:06 AM
To: [log in to unmask]
Subject: [TN] VIA pads


Good morning everyones around the World,

I have a design/manufacturing question.  If we use a 0,018" VIA, what is the
smallest pad size we can use on this VIA without causing problem in PCB
manufacturing?

thanks


Yvon Hache, P.Eng.
Tel: 506-863-2467
Email: [log in to unmask]

Concept + Inc.
Scientific Park, Suite 100
55 Crowley Farm Rd,
Moncton, NB
E1A 7R1

Tel: 506-858-4153
Fax: 506-858-4075
Web: www.concept-plus.com

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