Cant help other than to say scoring has often been one of those "suck it & see" things because
it's been done on 20 year old equipment & set-up by the rack of t'eye etc.
But that article looks interesting, can anyone recommend how I'd go about printing it out & still
keeping all the text within it?
Even Fire fox is cutting the Rh edge off.
Thank you,
Matthew Lamkin
-----Original Message-----
From: DesignerCouncil [mailto:[log in to unmask]]On Behalf Of Gary
M. Koven
Sent: 16 August 2007 17:05
To: [log in to unmask]
Subject: [DC] V-scoring and web thickness
I'm preparing a panel layout drawing.
For purposes of this post, all dimensions are in inches.
Material is 0.062 FR-4
Panel size is 12.000 X 8.500
Board size is 1.000 x 0.625, 120 boards per panel
I want to v-score these boards for "easy manual singulation" and would like
to put a note on drawing to make sure the cuts are deep enough. Now then,
READILY AVAILABLE REFERENCES
1) Apart from IPC-2222 Table 5 general parameters there appears to be no
other official IPC publications describing preferred web thicknesses.
2a) The best Internet reference I've been able to find is here:
http://www.tkb-4u.com/articles/other/vscore/vscore.php
2b) According to the matrix within this article, for a panel 10 to 15 inches
long and individual PCB 1.0 long, I should recommend 0.010 web thickness.
3) According to the LISTSERV archives, in message 006509 back in 2001, my
old colleague Ed Valentine (now retired) recommended 0.012 web thickness for
easy manual breakaway.
CONCLUSION
So if I didn't know any better and if nobody answers this, I'd end up with a
drawing note something like this:
"V-SCORE TO FINAL WEB THICKNESS OF 0.012" +/- 0.002" USING 30 DEGREE
CUTTERS"
I'm going to call some fab folk to get their take, but meanwhile, your
assistance here is kindly appreciated.
Thanks and Best Regards,
----------------------------
Gary M. Koven, C.I.D.
Dynazign, Inc.
Charlotte, NC, USA
704.405.1234
Veteran of the Marsh School
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