基于裸芯片覆膜的薄膜体声波滤波器

An Air-Gap Thin Film Bulk Acoustic Resonator Filter with Laminated Film Bare Die

该文研制了一种空腔型的薄膜体声波谐振器(FBAR)滤波器裸芯片。利用FBAR一维Mason等效电路模型对谐振器进行设计,然后采用实际制作的谐振器模型形成阶梯型结构FBAR滤波器,利用ADS软件对FBAR滤波器裸芯片进行优化设计。仿真结果表明,FBAR滤波器裸芯片尺寸为1 mm×1 mm×0.4 mm,滤波器的中心频率为3 GHz,中心插损为1.3 dB。采用空腔型结构并制备出FBAR滤波器裸芯片,同时采用覆膜工艺对FBAR裸芯片表面进行覆膜保护,避免裸芯片在使用或运输等过程中被损坏。测试结果显示,覆膜前滤波器裸芯片的中心频率为2.993 GHz,中心插损为1.69 dB;覆膜后滤波器的中心频率为2.997 GHz,中心插损为1.51 dB。对覆膜的影响和覆膜前后的差异进行了分析。

An air-gap thin film bulk acoustic resonator(FBAR)filter is developed.The FBAR one-dimensional Mason equivalent circuit model is used to design the resonator,then the actual resonator model is used to form a stepped structure FBAR filter,and ADS software is used to optimize the design of the FBAR filter bar die.The simulation results show that the size of FBAR bare die is 1 mm×1 mm×0.4 mm,the center frequency of the filter is 3 GHz,the center insertion loss is 1.3 dB.An air-gap FBAR filter bare die is fabricated,and the taped film technology is used to protect the surface of FBAR bare die to avoid the damage of bare die in the process of use or transportation.The test results show that the center frequency and insertion loss of the filter bare die are 2.993 GHz,1.69 dB respectively before the film is laminated,while after the laminated film is applied,the center frequency of the filter is 2.997 GHz,and the insertion loss is 1.51 dB.The influence of laminating and the difference before and after laminating are analyzed.