High Frequency, Low Loss, Additively Manufactured Hermetic Package

Abstract

This paper presents the development of a new type of hermetic cavity package for mmWave RF MMICs. The package features an all copper additively manufactured construction for optimal thermal performance as well as low loss air coax RF signal routing with a critical ceramic feedthrough to isolate the internals of the package from the external environment. With a simulated thermal resistance of 1 C/W, from die backside to package lid, and RF insertion loss of less than 0.5dB from 0–80Ghz, this package can support high power as well as high frequency MMICS. With no polymers in the construction of the package true hermetic performance is expected, making this package a high reliability option as well. For this paper two die were selected for demo packages. These die do not have surface mountable packages offered on the market. The die selected are the CMD247 30–40GHz Low Phase Noise Amplifier from Qorvo and the CHA2080-98F 71–86GHz Low Noise Amplifier from United Monolithic Semiconductors. RF insertion loss as well as environmental reliability will be demonstrated with these devices. The additive manufacturing process used is the proprietary PolyStrata® process developed by Nuvotronics. With the development of 14” panel substrate manufacturing line utilizing a mask-less process, fabrication process can support both high-volume, and high-customization without incurring prohibitive tooling costs.