IMPROVED TRANSFER MOLDING OF INTEGRATED CIRCUIT PACKAGES

Improvements in providing integrated circuit packages using transfer molding by encapsulating and underfilling integrated circuit chips attached to substrates are described. According to the invention there is provided method, mold and apparatus for encapsulating and underfilling an integrated circuit chip assembly consisting of an integrated circuit chip mounted on a substrate in a standoff relationship. The mold has a first portion and a second portio n wherein the first portion having first and second cavities and at least one channel interconnecting said first and second cavities. The first cavity is adapted to enclose said integrated circuit chip on said substrate. Means applies a clamping force to the first and the second portio ns of the mold to clamp the substrate between the first and second portions with the integrate d circuit chip located in the first cavity. Vent means exhausts air from the first cavity. Means for injecting encapsulant into the first cavity of the first portion at a location in the first portion remote from the point of connection of the channel to the first cavity, such that encapsulant flows around and underneath the integrated circuit chip and through the channel into the seco nd cavity to thereby underfill and encapsulate the integrated circuit assembly.