Ball grid array module

摘要

A Plastic Ball Grid Array electronic package of the Cavity Down type for use in HF application. The present invention allows to reduce the overall thickness of the package, by tailoring the different mechanical portions of the module structure (interconnection balls, grounded stiffener thickness). A thin dielectric layer is laid on a metal (e.g. copper) stiffener. A chip is attached on the same side of the dielectric layer and the electrical connections between the chip and the pads are done with metallic traces running on the surface of the dielectric layer. The external rows of balls are not connected to the circuit traces; they are electrically connected to the metal stiffener to realize the lateral shielding for the HF applications. The connection between the balls and the metal stiffener (which acts as the ground plane) is done by means of photovias. One of the more important aspects of the present invention is the dramatic reduction of the parasitic impedance.