US Patent 7256066 Flip chip packaging process

A flip chip packaging process uses an underfill as an encapsultant to reduce the possibility of delamination from occurring due to differential coefficients of thermal expansion, and thus the reliability of a flip chip package structure can be increased. Furthermore, the flooding of the encapsulant over the cutting line need not be taken into consideration for cutting the substrate. Therefore, the usage area of the substrate usage is increased, i.e., more chips can be mounted per unit area of the substrate.