A Mold Filling Model for Plastic Packaging of Microelectric Devices with Aperture Plate Molds.

Plate molds are used by AT&T Microelectronics for production plastic packaging of integrated circuit devices. Flow induced stresses encountered during the molding operation can damage the leadframes and wire bonds of the device, particularly in the new generation of fine pitch packages. Flow induced stresses can be reduced by lowering the velocity or viscosity of the molding compound as it flows over the device. A mold filling simulation program for plate molds was developed. It can be used to evaluate the effects of design, process and material parameters on the filling profile. As an example, the flow model can be used to determine the gate and runner sizes for uniform filling of all cavities in the mold.