Hello
Brad,
Thanks
for responding!
Our board design is two layer (1/2 oz. copper sandwiching .030"
FR4). I only took one semester of deformable solids, but I agree that a standard
layer of LPI should not be able to bow a .030" stack to any significant
extent... The concern was raised by our vendor (three letters - starts with a
D)
Your
input has emboldened me; we're going to stick with a full mask on the BGA side.
I'll keep you posted :o)
Thanks
again!
Tom
Ochenas
Maxtek
Components Corporation
Hello
Tom,
My that is an unusual request/requirement. .004 is the min I
like, it can go down to .003. Below that... I wouldn't trust it.
Actually the "ring" configuration you speak of is unique enough that I believe
it will be problematic. I would not do it.
As to the statement of
board warping due to soldermask on one side; I disagree. Soldermask,
especially LPI is pretty friendy stuff relative to warp. Unless there is
some unusual condition of board thickness or finish, one side solder mask will
not warp a board.
Brad Saunders
Coretec Boston Office
781 858
0783