James,

We score a lot a small parts such as you describe. We have found that the question is not distance or design. Its a question of material. We have found ( in conjuction with our customers) that CEM material is better suited for thin material V-grove breakaways. This is due to the fact that there isn't any glass fabric in the center of the construciton. Once scored the customer is only "snapping" resin. It is the glass fabric that forces the board to bend when you are trying to break it out after assemble. However, we are finding it more difficult to get. We are currently testing glass Steal material. We do not have any results yet.

Ed Cosper
Director, Quality Assurance and Engineering 
Graphic Electronics, Inc.
Tulsa, OK


----------
From:  [log in to unmask][SMTP:[log in to unmask]]
Sent:  Tuesday, May 13, 1997 11:22 AM
To:  [log in to unmask]
Subject:  small pcb  "V" score

     We are in the design stage of a new program and the designer is using 
     a small pcb in the system. The problem I see is the board is .800" x 
     2.2"  with a couple of components on it.  The components are no closer 
     that .250 from the edge and the board thickness is .028.  In the past 
     when we have "V" scored small boards and then broken them away after 
     population. We have had solder joints  fracture and a large amount of 
     rework.  My question is, is there a distance that a component must be 
     from the edge of a board when using "V" scoring to prevent damage to 
     solder joints during board separation.

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