Electronic – Current capacity of laser drilled micro vias


Does anyone have a source, formula, or calculator for the current carrying capacity of laser drilled micro vias? I haven't found anything great yet. I'm sure it depends on plating too. Is there a difference between copper filled, conductive filled and open or non-conductive filled?

For example I'll probably use a 5mil laser with a 2-3mil dielectric and conductive fill them and plate flat.

Oh and I did ask my vendor but haven't heard back…

edit: I don't think this is a duplicate of how much current a via can carry because a laser drilled via structure is different than a drilled via. In fact I've read in multiple places that they carry more current than a traditional via so I was looking to see if anyone had an answer.

Best Answer

If this is a critical application, you should sample the board with the laser vias and then micro section a number of them and examine the cross sections under an SEM. A discussion with your board supplier about their process controls to ensure consistency in the deposition thickness is also warranted.

A less rigorous test, although perhaps a good supplementary one, is to build a board with sample vias and conduct current tests between the planes and measure the voltage drop. Statistical sampling should be used to obtain more reliable results.