Can someone please advise me on whether it is possible to use a BGA on
a 4 layer board? The center layers ares Vdd and Gnd. So the signal
layers are top and bottom.
The Ball Grid Array is only 4x4 or 16 pins, with a .4mm pitch and ball
of .29mm/.26mm/.23mm (I don't understand this either, is that the max,
avg, min size??).
I have read through the posts, created the device but can't get it to
route for the two center rows. There is a lot of room on the board.
But just looking at the grid I can't really see how to get the auto
router to do this unless there is a way to do a drill hole in the
center of the Ball and plate that through to the opposite side.
But I have no clue on how to get this to work, any advice would be
appreciated. Thank you.