This letter provides an overview of the metal-embedded chiplet assembly for microwave integrated circuits (MECAMICs) technology. MECAMIC is a 2.5-D wafer-level packaging approach that provides seamless heterogeneous integration capabilities of compound semiconductor transistors (e.g., GaN HEMTs) with passive components and interconnects using a backside metal embedding process. The chiplets are embedded in through-interposer cavities, and the backside metallization locks the chiplets into position while providing dc and RF ground for the high-frequency circuits. With this hybrid manufacturing approach, high-performance RF ICs can: 1) be designed using the best transistor technology for the function; 2) be fabricated in short cycle times through hybrid manufacturing; and 3) compete performancewise with monolithic circuits. We demonstrated an $X$ -band power amplifier circuit realized in MECAMIC with a saturated output power of 31 dB and a peak power added efficiency of 54%, which compared favorably to its monolithic GaN monolithic microwave integrated circuit (MMIC) counterpart. The MECAMIC process cycle time was $4.5\times $ faster than the monolithic process.

中文翻译：

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微波集成电路的金属嵌入式小芯片组件

这封信概述了用于微波集成电路（MECAMIC）技术的金属嵌入式小芯片组件。MECAMIC是一种2.5维晶圆级封装方法，可使用背面金属嵌入工艺提供具有无源组件和互连的化合物半导体晶体管（例如GaN HEMT）的无缝异构集成功能。小芯片嵌入到中介层腔中，背面金属化将小芯片锁定在适当位置，同时为高频电路提供dc和RF接地。通过这种混合制造方法，可以实现高性能RF IC：1）使用功能最佳的晶体管技术进行设计；2）通过混合制造在短周期内制造；3）与单片电路在性能上竞争。我们展示了 $ X $ MECAMIC中实现的宽带功率放大器电路，其饱和输出功率为31 dB，峰值功率附加效率为54％，与单片GaN单片微波集成电路（MMIC）相比具有优势。MECAMIC处理周期时间为 $ 4.5 \次$ 比整体处理更快。