FAQ # 6 | accusystemscorp

The Pocket Guide to Excellent V-Scoring

FAQ # 6 -- Some Finer Points

Cost Savings...

We haven’t talked much about the material savings aspect of v-scoring because it is fairly well known that, depending on the individual board size, when you eliminate the spacing necessary for routing, (typically .062" to .250" between each board) you may find that you now have enough room to add additional rows of boards to the fabrication panel. This can effectively reduce the number of panels that need to be processed, and the amount of laminate wasted. This translates into other measurable cost savings throughout the shop as well.

Assembly Rails...

While it is always a boon to increase your panel efficiencies, it is also critical that we do not lose sight of the overall yield. Surprisingly enough, many assembly situations can benefit from adding a section of throw-away material onto two, three or four sides of an assembly panel. What we are talking about here, is the growing application of break-away rails to individual circuits and/or panels. The principal usage of these rails, is to allow densely packed SMD boards to be centered in the reflow or wave equipment, and to provide a temporary fixturing area. This fixturing area also can provide a place for coupons, fiducials, etc., as well as act to prevent the possibility of heat sinking and/or heat absorption at the board edge.

Blade Angles...

You may have noticed the absence of the mention of larger blade angles (45, 60, 90 degrees etc.). Although the data we have shown for 30 degree blades can be extrapolated out for usage on other angles, we suggest you consider the following;

If there is no specific use for the bevel-type finish of a larger angle blade, we contend that the clearance/leverage advantage that they offer for separation, is a poor substitute for using the proper web thickness. If this seems a little radical...then good! There are, of course, many specific application blades that, for design reasons, must be used. Beyond that however, there seems to be a great deal of confusion over blade angles. As far as we can tell, larger blade angles appear to be a throw-back to an earlier time when space was less of an issue, and Z-axis control was not as precise as it is today. With today’s designs, 30 degree blades seem to offer the optimum balance of a narrow score path, ample clearance for separation and acceptable blade life performance.

"Jump" Scoring...

You may have heard this popular term before. It refers to the ability to program a certain length for a score line and then "jump" over a certain programmed distance (section of the board). The use of "jump" scoring can provide a rigid assembly panel, that can be de-paneled easily without damage to even the most sensitive solder joints. With the proper application of this capability, coupled with the use of rails, virtually any assembly goal can be achieved.