If only one side has parts then there is no problem. If you have parts on
two sides then a holder can easily be made with cut up "Rubber Feet".
However both the holder and the board must be held steady and this varies
with the assembly machine.
Bob Kondner
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Carl VanWormer
Sent: Tuesday, December 08, 2009 10:09 AM
To: [log in to unmask]
Subject: [TN] Looking for guidance on V-Score requirements
Background:
We have a couple of small (2"x2" and 2"x3") boards that arrive as pallets
(x6 and x4) for surface mount assembly (pictures available upon request).
Since some components are placed too close to the edges for the "pizza
cutter" separation machine, the assembly house is separating the boards by
hand. Since the v-scores run the lengths of the boards, I worry that there
is too much twisting force applied to the board, risking fracturing of some
of the components. I am considering asking the board fabrication house to
route most of the board edges, leaving the v-scores for only a small length
at the PCB corners, maybe 1/4" or so. I don't want to reduce the stiffness
of the pallet too much, making the board difficult to run through the
assembly process. My hope is to simulate the routing and "mouse-bites" type
pallet, without having to deal with the ragged protrusions of the left-over
"mouse-bite" broken edges.
Question:
Are there guidelines on the limits of structural material required to keep a
board stiff enough to avoid irritating my assembly house?
Extra credit question:
Is there something else I should be doing?
Thanks,
Carl
Carl Van Wormer, P.E.
Senior Hardware Engineer
Cipher Systems
1800 NW 169th Place, Suite B-100
Beaverton, OR 97006
Cipher Systems (503) 617-7447
Direct Line (503) 425-5163
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