详细说明：

PITCH=0.50 PITCH=0.65 PITCH=0.75 PITCH=0.80 PITCH=1.00 OTHER PITCH 　 BGA(Ball Grid Array). A popular surface mount chip package that uses a grid of solder balls as its connectors. BGA chips are easier to align to the printed circuit board, because the leads, which are called "solder balls" or "solder bumps," are farther apart than leaded packages. Since the leads are underneath the chip, BGA has led the way to chip scale packaging (CSP) where the package is not more than 1.2x the size of the semiconductor die itself