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V-scoring design and equipment questions

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#42109

V-scoring design and equipment questions | 12 June, 2006

Why do they say to specify the depth of the score, rather than the thickness of the web? How does the scoring equipment work? Is it two blades that you can set the separation distance? Or is it one blade, that you have to run the board through twice?

Thanks for your time.

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RDR

#42116

V-scoring design and equipment questions | 12 June, 2006

As far as wich is spec'd it makes no diiference since they have reltionship with each other, Cant change one without the other. V score equipment I have seen is one blade and they are run through twice. their may very well be that there are dual bladers as well.

Russ

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#42117

V-scoring design and equipment questions | 12 June, 2006

IPC spec is V-score shall not be more than 1/2 board thickness. They should be V scoring 1/4 off top and 1/4 off bottom equally.

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#42121

V-scoring design and equipment questions | 12 June, 2006

Which spec is that in? I'm seeing web thicknesses of .015 or thinner being suggested for a .062 board, way thinner than 1/2 the board thickness.

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#42122

V-scoring design and equipment questions | 12 June, 2006

Its in the IPC 600 bare-board specification.

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#42123

V-scoring design and equipment questions | 12 June, 2006

Hi,

A little off subject but I just finished a quick little experiment where I placed 0201 to 1206 and some ceramic resonators at specific distances off the scored edge. The distances from scored edge ranged from 0.025" on up at 0.025" increments. As suspected, the larger components cracked when separated using pizza cutters. However, the linear chopper guitine style did not crack any components including those placed 0.025" off the score edge.

Thanks,

Chris

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#42125

V-scoring design and equipment questions | 12 June, 2006

OK, Pete, I just looked all through IPC-A-600G. Saw no mention of scoring anywhere. Please provide specific section number info. Thanks

By the way, Chris, thank you for the information - that is really interesting stuff. Would you be willing to answer/share specific questions/information from your testing?

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#42140

V-scoring design and equipment questions | 13 June, 2006

IPC-2222, 5.3.1 defines the parameters of making scoring cuts and the tolerance of the cuts, but does not specify the cuts.

Our spec for 0.062" thick FR-4 boards is: 0.018-0.024"

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Board House

#42185

V-scoring design and equipment questions | 14 June, 2006

Hi all,

The majority of score machines used today have a top cutting wheel and bottom cutting wheel. This way they can score a line in one pass and saves on programming time, Panels are typically scored in one direction first and then the panel is rotated and scored the other direction, so if your panel is 18x24 they would score the 24 first then the 18.

Typical call out on a .062 thick board would be 30 degree angle with .014 +/-.003 Web left. Any thing thicker makes it real tough to snap with out a cookie cutter and may cause fracturing in the material especially with the lead free materials like IS410.

Regards,

Mike

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