Wireless MMIC chip packaging for microwave and millimeterwave frequencies

摘要

A wireless MMIC chip packaging scheme where the MMIC chip (38) is maintained right side up. The MMIC chip (38) is positioned within a cavity (40) of a fixture (42), where a backside metal layer (44) of the chip (38) is mounted to the fixture (42) by a conductive epoxy layer (48). RF and DC via feedthroughs (62, 64) are strategically provided through the chip (38), and are electrically connected to isolated islands (70) in the backside metal layer (44). Substrates (52, 56) are provided that carry microstrips (54) and electrical traces (56), and that extend below the chip (38) so that ends of the microstrips (54) and traces (56) make an electrical connection with the isolated islands (70). In an alternate design, the substrate (80) extends completely across the backside of the chip (38), and ground vias (84) extend through the substrate (80) to connect the backside metal layer (44) to the fixture (42).