Solder ball
In integrated circuit packaging, a solder ball, also a solder bump (ofter referred to simply as "ball" or "bumps") is a ball of solder that provides the contact between the chip package and the printed circuit board, as well as between stacked packages in multichip modules.[1] The solder balls can be placed manually or by automated equipment, and are held in place with a tacky flux.[2]
A coined solder ball is a solder ball subject to coining, i.e., flattening to a shape resembling that of a coin, to increase contact reliability.[3]
Usage in flip chip method
-
Pads -
Balls -
Alignment -
Contact -
Solder reflow -
Adhesive underfill -
Final result
See also
- Head in pillow defect, a solder ball failure
References
- ^ Definition of: solder ball, PC Magazine glossary
- ^ Soldering 101 - A Basic Overview
- ^ Patent US 7622325 B2, prior art description