随着信息时代对通信带宽和通讯速率的需求急剧上升，微波光子技术得到研究人员的重点关注。其中超宽带光电探测器芯片作为微波光子技术的核心技术，需要相应高性能高频封装方案的支持才能得到进一步的应用与拓展，所以针对高饱和且高带宽探测器芯片的高频封装方案尤其重要。本论文针对高速背入射型光电探测器的超宽带（100 GHz）的封装结构开展设计与实验研究。在0-100 GHz范围内，考虑特征阻抗随频率变化的性质与微波传输损耗大小，通过有限元仿真 (HFSS) 结合电场能量分布的分析实现了对微波传输线的高频结构设计。新的微波传输线在100 GHz以内能有效抑制模式谐振现象，其传输损耗低于0.5 dB，反射系数低于-15 dB，并对其结构参数进行10%左右的加工容差仿真以检验其加工的可行性与可靠性。在倒装焊工艺方面，首先本论文通过高频仿真软件建模分析出倒装焊点半径尺寸是影响芯片频率响应的主要原因，然后设计对比实验优化低损耗倒装焊条件。最后采用等效电路模型拟合测试结果，对芯片倒装焊后进行参数提取，得到倒装焊工艺引入电阻仅为12 Ω，寄生电容仅为12 fF。在关键模块封装工艺方面，本论文首先介绍在光电探测器芯片中常见的封装模块与优缺点，然后介绍本实验室设计的蝶形封装结构。接下来进一步详细展示了模块封装中从探测器芯片到模块化封装的详细步骤与注意事项。最后详细介绍在不同封装阶段下本实验室采用的不同测试系统与测试结果。本论文最终完成3dB带宽为52 GHz的光电探测器封装模块。

Microwave photonic technology starts to get increasing attention by scientists when the demand for communication bandwidth and communication rate rapidly surge in the information era. Uni-traveling-carrier photodetector, as the key part of microwave photonics, need the corresponding development of high-performance & high-frequency packaging technology to expand further applications, and thus it is significant to dig into high-frequency packaging for high saturation & high-bandwidth photodetector.In this thesis, the design and research of the ultra-wideband (100 GHz) packaging for the back-incident high-speed photodetector is carried out. As for the consideration of the characteristic impedance changing with frequency and the microwave transmission loss within 100 GHz, our lab adopts the HFSS simulation with the electric field distribution to realize the design of a wideband microwave transmission line, which can effectively suppress the mode resonance within 100 GHz. Its transmission loss is less than 0.5 dB and the reflection coefficient is less than -15 dB. Moreover, the feasibility and reliability of processing are verified by the simulation of 10% fabrication tolerance of its structural parameters.In the flip-chip section, this paper uses simulation software modeling to analyze that the radius of the flip-chip solder is the main parameter that affected the frequency response of the chip and then sets comparative experiments to optimize the flip-chip conditions. Finally, the equivalent circuit model is used to fit the measurement result to extract the parameters of the flip-chip process, including 12 Ω introduced resistance and 12 fF parasitic capacitance. In the module packaging section, this paper introduces the pros and cons of common packaging modules, and the steps and precautions of the module package for the photodetector are further shown in detail. Finally, it offers the different measurement systems and test results adopted by our laboratory in different packaging stages. This thesis finally completes an ultra-wideband UTC-PD packaging module with a 3 dB bandwidth of 52 GHz.