Term of the Moment
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Definition: BGA
(Ball Grid Array) A popular surface mount chip package that uses a grid of solder balls as its connectors. Available in plastic and ceramic varieties, BGA is noted for its compact size, high lead count and low inductance, which allows lower voltages to be used. 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. See surface mount, chip package, MicroBGA and flip chip.
BGA Solder Balls
BGA Package Types
Different Contact Types
These are the undersides of BGA packages showing the solder balls. The small one on the ruler is a µBGA (MicroBGA) chip from Tessera. Using the entire square of the chip package for leads is an advantage of the BGA method. (Image samples courtesy of Amkor Technology, Inc.)
These cross sections show BGA packages in standard and CSP varieties. (Illustrations courtesy of Joseph Fjelstad.)
The solder balls can be made to connect to the printed circuit board using various contact methods as illustrated here. (Illustrations courtesy of Joseph Fjelstad.)