基于晶圆级扇出式封装技术的毫米波封装天线的研究

Antenna-in-package (AIP) has wide application and great demand in millimeter wave systems. The AIPs based on conventional packaging technologies have disadvantages of lossy, bulky volume and high cost. Fan-out wafer level packaging (FOWLP) technology can efficiently solve these problems. Some problems in research and application of AIP base on FOWLP need to be solved, for example, the accurate model for loss of transmission line on redistribution layers (RDLs) is lacked, the coupling mechanisms and effects between AIP and the on-chip circuits is not fully understood, and the AIPs on multilayer FOWLP have not been studied. This project addresses the problems of millimeter wave integrated antenna design on FOWLP. Based on the transmission line model, the effect of surface roughness of the RDL and the material property of the molding compound material on the RDL transmissions lines is investigated. A coupling mechanisms model between AIP and on-chip circuits will be given based on equivalent circuit and surface wave theory. An antenna will be integrated with a chip on multi-layer FOWLP to achieve an AIP structure with low coupling effect to the on-chip circuits and good performance. The implementation of the project will effectively reduce the cost of millimeter wave AIP, and will also enrich and stimulate original research in the field of microwave engineering and material science.

封装天线在毫米波系统中有着广泛的应用和极大的需求。基于传统封装工艺的封装天线存在高损耗、体积大、和成本高的问题。晶圆级扇出式封装技术（FOWLP）能有效的解决上述问题。在基于FOWLP封装天线的研究和应用中存在的问题有：无有效的针对FOWLP 传输线损耗的模型；无针对FOWLP天线与芯片电路的耦合模型；无对多层FOWLP天线的研究。本项目针对FOWLP封装天线在设计时存在的问题进行研究，从传输线损耗模型出发，研究金属表面粗糙度、模塑化合物介电常数和损耗对天线性能的影响；从等效电路法与表面波理论出发，推演出适合FOWLP的封装天线与芯片电路的耦合模型；从天线设计理论出发，提出多层FOWLP的封装天线的设计方法，实现与芯片电路低耦合、高性能的封装天线结构。该项目的实施有助于推广FOWLP在毫米波封装天线中的应用，还将丰富并激发毫米波技术和材料科学领域的原创性研究。

本项目面向毫米波封装天线，研究内容是针对传统封装工艺的封装天线存在高损耗、体积大、和成本高的问题，提出基于多层扇出型晶圆级封装工艺的封装天线设计方案。我们从传输线损耗模型出发，使用微带环形谐振腔法测试模塑化合物的介电常数和损耗正切角，研究模塑化合物介电常数和损耗对天线性能的影响；从等效电路法与表面波理论出发，推演出适合FOWLP的封装天线与芯片电路的耦合模型。设计了应用于汽车短距雷达的单发射单接收1×1和双发射双接收2×2的微带贴片阵列天线，分析了硅基芯片、传输线布线以及芯片实际板图中的各种因素对于天线的互耦影响，给出了设计指导，最后对实际封装走线板图进行了后仿和加工；从天线设计理论出发，提出多层FOWLP的封装天线的设计方法，设计了应用于5G通信的多端口超表面封装天线，多端口功率组合栅格阵列天线和单层互连磁电偶极子天线阵列。