The fabrication of modern integrated circuits (ICs) involves several process steps. Integrated circuits are first fabricated on/in a semiconductor wafer. The semiconductor wafer contains multiple duplicated semiconductor chips, each including integrated circuits. The semiconductor chips are then sawed from the semiconductor wafer and packaged. The packaging process has two main purposes: to protect delicate semiconductor chips, and to connect interior integrated circuits to exterior connections.
As semiconductor devices reach higher levels of integration, the packaging of a semiconductor chip accounts for a considerable portion of the cost of producing the device. Failure of the package leads to costly yield reduction.
There are challenges in fabricating reliable package structures.