v-score troubles

[Carl_at_xrite]

Howdy all,
Recently due to assembly volume we started v-scoring rectangular boards in order to maximize our usable area instead of routing and breakout tabs.
Manufacturing is complaining that the boards are to hard to break out of the panels.

The board is roughly 2.25" by 1.5" and has a score depth of .024" per side leaving .015" web thickness remaining.

I had specified a 10 mil web thickness but due to the number of boards in the panel the fab house wanted to go to .020 web thickness which I declined.

What is every one else doing to insure an easy break out from the panel?

If manufacturing keeps complaining about this we will be forced to go back to routed boards and having to cutr them away and wasting material.

Thanks,
Carl Goldenbusky
Sr. CAE and PCB Designer
X-Rite Inc.

[Colorado-PC-Dude]

Carl,

We v-score almost everything here, including boards that are not rectangular (as long as they have enough length on the flat sides). 0.015"-0.020" remaining web thickness is just about right. Less than 0.015" starts getting too weak to handle, especially on larger boards.

Ben

[robert Tarzwell]

Hi the exact depth is a some what of a feely type thing, on larger boards we left 15 to 18 mils, on smaller boards 12 to 14 mils. do a cross section of a score to determin the exact depth, The materila does somwhat chage the depth, fr4 is the softest, bt epox is the hardest and poly is in the middle. To help your assemblers we use to make a hard rubber vice that people could use to snap the boards off, the rubber helped prevent damage to the board , we tried to stay away from components. THere is also a saw made that cuts out the scored panels after assembly, dont know a manufacturer but a quick web search will pop some thing up.
hope that helps Robert Tarzwell pcb
books at megadawn.com.

[Carl_at_xrite]

Thanks for the input !!
I forwaded this on to our Manufacturing Engineers and hope they can do something with it.

Thanks again,
Carl