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Standard Small Via Sizes

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Topic

TheBFG

United Kingdom
61 Posts

Posted - 03 Nov 2011 : 16:38:59

I'm currently using 20 thou drill and 40 thou pad vias, giving a 10 thou annulus.

With the ever shrinking size of components via size seems to be having a major impact on board size.

Just wondered what effect using smaller vias has on cost, what sizes are people routinely using?

Thanks a lot

Iain Wilkie

United Kingdom
1015 Posts

Posted - 03 Nov 2011 : 17:23:58

12 thou holes are pretty much standard now and if really want to get down in size I have used 8 thou. Don't really think it makes much difference to cost.

Iain

davep

United Kingdom
101 Posts

Posted - 03 Nov 2011 : 19:57:26

There are companies that can Laser drill to 1 thou.

TheBFG

United Kingdom
61 Posts

Posted - 04 Nov 2011 : 15:21:49

So 12 thou hole with 32 thou pad = 10 thou annulus, or have you used smaller pads than that?

Iain Wilkie

United Kingdom
1015 Posts

Posted - 04 Nov 2011 : 18:49:18

12 thou hole with 24 thou pad.
8 thou hole with 18 thou pad.

Check with your manufacturer what they can handle....

Edited by - Iain Wilkie on 05 Nov 2011 11:23:40

edrees

United Kingdom
779 Posts

Posted - 05 Nov 2011 : 15:59:26

Smaller holes esp. multi-layer PTH => more cost & less choice of manufactures. Read
http://www.eurocircuits.com/index.php/technology-guidelines/pcb-design-guidelines
for good general advice.

TheBFG

United Kingdom
61 Posts

Posted - 07 Nov 2011 : 10:05:25

Thanks edrees. That is a good source of info.

It seems the answer to my question is that the cheapest standard via will be 14 thou drill and 7 thou annulus for a 28 thou total size. (Class 6-C)

It also says 6 thou track / 6 thou gap is fine for all layers. I'm currently using 10 thou for both, so I could save some space there too.

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