I read the responses to the inquiry from Ron Oneal on breakaway tab
remnants. We use the same specifications that John Laur had mentioned
(four 0.036 in. holes spaced 0.050 in. apart). 

  My question has do with the other side of the breakaway holes facing
into the board. I have not found any specific recommendations on how
close traces should be to these breakaway holes. We have a board (0.062
in. thick) that has a trace that is 0.079 inches away from these four
breakaway holes, and we occassionally have a board scrapped out due to
trace damage during breakaway (our last lot of 40 boards had 1 board
scrapped for this). The board is double sided and has a high expense at
this point. Occassionally a very small piece of fiberglass will tear
away with the breakaway portion and damage a trace.

 We have discussed what would be a reasonable trace spacing from the 
breakaway holes to prevent this occassional scrap from happening. The
initial figure of 0.200 inch spacing was deemed way to much by the
design community. Another suggestion of two times the board thickness
(0.124 inches in this case) was proposed. 

1) Has anyone else seen similiar damage of this sort during breakaway ?  
2) Is there anyone who has experience with a miminum trace spacing from
   breakaway holes that works well ?
3) Is there an accepted standard or Rule of Thumb (such as two times the
   board thickness) that anyone has used without incident in moderate  
    volumes (200 plus a month)?

Thank You in advance for any comments.
Bob Cronin
Eastman Kodak

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