We see most fab drawing call-outs at 30 degrees-some 45 degrees. We like to 
use 20 degree blades for scoring through plated edge castellation holes. I 
have never been asked for any angle larger than 45 degrees.

At 06:32 AM 12/14/2005, you wrote:
>Good Morning All,
>
>My question for today is as follows;
>
>IPC-SM-782A suggests the angle of the v-score (v-groove) be 90° max to 60° 
>min.
>
>The folks at Accusystems and V-Score Central prefer 30° with the following 
>quoted explanation;
>
>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.
>
>Anybody care to weigh in on what is the best?
>
>I'm trying to define how our boards will be scored as we have had some 
>issues with boards from a new fabrication house.
>
>Thanks in advance.
>
>Phil Nutting
>
>
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