Flip chip assembly for sub-millimeter wave amplifier MMIC on polyimide substrate

The sub-millimeter wave amplifier MMIC with flip-chip mounting on polyimide substrate has been realized. The thickness of the substrate and the pitch of GND vias are designed to suppress the air radiation from the slot pattern in the substrate. The test results of the micro-strip line formed on the polyimide substrate shows that the design is applicable to the assembly operated up to 320 GHz. The InP HEMT amplifier MMIC with the assembling technique achieved the operation in 240-260 GHz frequency band with the gain of 20 dB.