I am trying to place some very small feed-throughs between the pads on a BGA100 0.8 mm device.
I don't understand the white symbols shown on layer 44 on a board file for a feed through .
Using the Info button on a via, I can set the diameter to 0.485 and the drill to 0.25, which seems to fit well within the BGA pins.
The via is surrounded a white circle crossed by a white line at 45 degrees, both on layer 44.
What do the circle and line represent and where are their dimensions derived?
I assume that they are keep-out symbols but how can I change their values?
Thanks in advance for any help,