The push for higher communications frequencies, greater system integration, and smaller space imparts many unique challenges on RF and packaging engineers in the development of next generation cellular products for 5G, WiFi 6, Military, and other applications. 3DGS presents a manufacturing platform for the production of vertically stacked glass substrates with heterogeneously integrated surface mount devices for advanced RF systems-in-package. This work includes the design, fabrication, and assembly of a true 3D Heterogeneously Integrated vertically assembled half-duplex 6-12GHz Tx/Rx module using 4 stacked glass layers with 14 embedded components (e.g. power amplifier, low noise amplifier, and bypass capacitors) with excellent simulation vs. measurement agreement. The designed system incorporates a total of 4 glass layers, 9 integrated cavities, 14 embedded components packaged with in a 7mm x 8mm x 1.2mm (height) system footprint representing an approximately 60% reduction in footprint and a 25% reduction in weight over a PCB with an equivalent build of materials. The innovativeness is to change the paradigm from 1) wafer fabrication followed by 2) packaging to 1) wafer fabrication followed by 2) “scale-in” (glass layer fabrication) and finally 3) “scale-out” (stacking glass layers vertically to produce true 3D Heterogeneously Integrated Systems-in-Packages). In this work, we present design, production, assembly considerations that impact size, weight, and performance (SWAP) metrics for a variety of product definitions.
Flemming et al. (Tue,) studied this question.