The distance between solder mask and solder pad shall min. be 50µm. If possible use a distance of 75µm.
















Min. width of the solder mask is 100µm.
 
















Remember to over print viaholes under BGA .

If you make the opening in the solder mask  larger then the viahole, then the viahole is defined as an open viahole. There shall be no solder mask in the viahole.




 

A tented viahole shall have no opening in the solder mask. The viahole shall be covered with solder resist and the viahole shall be closed.

A plugged viahole shall be filled up with solder resist or epoxy. This is very expensive and before you specify plugged viahole ask your customer if this is really necessary.

If you specify over printed viahole then there will be some solder resist in the viahole.