FEDEVEL
Platform forum

mostafa222 , 01-30-2017, 12:32 AM

Hi. What is the diameter of uVIA?

mairomaster , 01-30-2017, 01:40 AM

It's your choice depending on your needs with the particular board and what can your manufacturer produce. Most of the manufacturers I've worked with are not very happy going below 0.1/0.3 mm (hole/pad diameter). They always recommend to me to have at least 0.1 mm annular ring. I've used uvias down to 0.1/0.25 mm.

robertferanec , 01-30-2017, 10:21 AM

Same here ... the smallest we use are 0.1 hole / 0.27mm diameter.

But be very careful. The hole size depends on your stackup. Many manufacturers provide you with VIA ratio number (VIA hole vs VIA length) and for uVIAS it is very often 1:1 .... so if you need to drill 0.2mm, minimum hole is 0.2mm ... if you use 0.1mm hole, you only can drill up to 0.1mm - that is the maximum distance where your second layer will need to be placed.