基于厚薄膜混合基板的超宽带垂直互联设计

Ultra-wideband vertical interconnect design based on thick film hybrid substrate

针对三维集成电路中基板层间信号垂直互联问题,基于厚薄膜基板的优良特性,设计了一种超宽带的同轴到带状线再到微带线的过渡结构,能够工作到80 GHz。这种垂直结构采用LTCC为基板,旋涂BCB膜层,适用于系统级封装。该结构利用"水滴"匹配的方法,并嵌入空气腔抑制寄生电容,有效地改善了互联结构的射频传输性能。仿真结果表明,其背靠背(同轴-带状线-微带线-带状线-同轴)结构在0～80 GHz频段范围内,回波损耗均低于-17 dB,插入损耗均优于-0.5 dB,驻波比均低于1.35,具有良好的超宽带传输特性。

In order to solve the problem of vertical interconnection of inter-layer signals in three-dimensional integrated circuits,based on the excellent characteristics of thick film substrates,an ultra-wideband coaxial to stripline to microstrip transition structure is designed,which can work up to 80GHz.This vertical structure uses LTCC as the substrate and spin-coats the BCB film for system-in-package.The structure utilizes a“water droplets”matching method and is embedded in the air cavity to suppress parasitic capacitance,which effectively improves the RF transmission performance of the interconnect structure.The simulation results show that the back-to-back(coaxialstripline-microstrip-stripline-coaxial)structure has a return loss of less than-17dB in the frequency range of 0~80 GHz,and the insertion loss is better than-0.5dB,and VSWR are lower than 1.35,which has good ultra-wideband transmission characteristics.