There are many ways you can try to control this process.

First is to change the design to do more routing in the critical dimension
areas and then use the scoring (either L-Cut or V-Cut).

Second is to use L-Cut (instead of V-Cut) as this will give you better
control on your burr dimension.  And have a tight tolerance for the upper
and lower side offset.  And minimized the web thickness as much as possible
without breaking them during component mounting.

Third, you can use a side grinding machine to automatically sand the edges
if you do not have a dust problem.  We have a unit we built by ourselves
which works very nicely.

The dimension changes due to burr will depend on each type of board (due to
glass size and structure) you are talking about as well as how you
depanelize the boards.  We did an extensive study with our customer about
five years ago.  To get the exact record it will take too much time.

We hope this helps a little.


Best Regards,
One Kyu Son



At 05:39 PM 1/16/98 +0000, you wrote:
>     Good day Folks,
>
>     We face dimension problem after depanellise the v-scoring board. The
>     board's thickness is 0.062" and the v-scoring remaining thickness is
>     0.015". After depanellise, the board dimension is found to increase by
>     0.01".
>
>     According to the fab. house, this is caused by the burr (protrusion)
>     after depanelling the board.
>
>     Is there any standard spec. for the burr after depanelling the
>     v-scoring board? What is the general dimension tolerance used in
>     design the board with v-scoring?
>
>
>     Thanks
>
>
>     Robert
>
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