Basics of Ball Grid Arrays (BGAs)

Ball grid arrays are the boon and bane of engineers and printed circuit board designers the world over. Their unparalleled pin density and low lead inductance are essential in today's high pin count, high frequency integrated circuits. However, that same pin density and unique interface create a challenge unique unto themselves. These challenges need to be faced head on since the ball grid array (BGA)is prevalent in modern PCBs. While there are entire textbooks that cover the topic of BGAs,their use and fan out techniques, the quick overview provided here offers an engineer a good starting point for improving BGA designs.