Min spacing for land patterns from PCB edge

Here's what we suggest: * Keep a 5-mm space between a board edge and a ceramic capacitor. * Mount the capacitor parallel relative to the edge. * Design pads about a half of the termination. * Fixture the board when using your pizza cutter.

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Min spacing will be 0.75'' on all the 4 edges

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FSW,

Another suggestions is if you have rail on your product and you are concerned about stress fracturing certain components you could add a routed slot to add relief in that area. So when you snap the rail off their would be no stress in that area due to you routed a slot in that part of the rail.

We do this for a couple of our clients.

other wise Standard spacing most board houses would like to see is.

If Routed : .015 If Scored : .020

Regards,

BoardHouse

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Hi,

I did a large DOE on this a couple of years ago. The smaller the component the closer to the edge you can place. 0201s crack less than 0805s. Also capacitor dielectric comes into play COG,NP0 > X7R >Z5U,Y5V. Y5Vs crack more than NPOs. Ceramic resonators crack often as well. I found that the chop style like the Fancord VPD5 is the lease stressful of the V-Score cutters. We have run as close as 0.025" to the edges with 0805s with no cracking on 0.062" thick PCBs with VPD5. We do this because we have to and not because we want to do it.

Chris

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If you have jobs where you can not, there is a company in Japan that makes the best v-groove depanelers called TST, 'guru's in v-groove depanelising'. Their systems can be supplied to reduce stress on cutting to near zero compared to CAB and other lower cost, lower tech systems. Machines on offer have dual top blades that enables your to pre-cut then cut again thus lowering the separation. They can measure the stress being induced on your assemblies during cutting process and tune the blade profiles and setup of your machine to suit your target PCB's. Of course the v-groove profile-quaility is very important and impacts on stress also.

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