A Low Loss Die-Embedded Glass Substrate for 140 GHz InP Power Amplifier Integration

We present a novel packaging solution for 140 GHz InP power amplifier (PA) integration using an advanced die-embedded glass substrate. This marks the first functional demonstration of a die-embedded glass package for D-band (110–170 GHz) applications, effectively tackling both electrical and thermal challenges at high frequencies. We embed the 140 GHz InP PA die into the glass substrate and employ micro-vias for die-to-package interconnects, thereby eliminating assembly. The interconnects using micro-vias introduce less than 1.04 dB loss per interconnect from 110–170 GHz. Additionally, thermal management has been effectively addressed by directly electroplating a copper sheet onto the backside of the die, ensuring optimal heat dissipation and maintaining the integrity of the PA under high heat density conditions. With the electrical, thermal, and fabrication benefits, the die-embedded glass package shows immense potential in the development of wireless modules in D-band or higher frequencies.