| In recent years,with the development of 4G networks,the demand for smart phones has soared.According to different functional requirements,there are dozens of SAW filters and duplexers used in each smart phone.The market demand brings great opportunity for the development of SAW filter industry.At the same time,it also puts forward higher requirements for the electrical performance,size and reliability of the device.This thesis focuses on the design of SAW RX filter in BAND13 for mobile phones on 42°YX LiTaO3 piezoelectric material and its fabrication realization.Firstly,after deeply studying the basic theory of SAW and all kinds of design structures of the SAW filter,the structure of DMS plus a series resonator is adopted according to the requirements of the electrical performance,size and reliability of the device.Secondly,through modeling and co-simulation,the electrical performance of simulation is obtained.According to the simulation results,the design structure is adjusted and optimized,and the optimal electrical performance is obtained,and the layout of the device is outputted.In this thesis,various simulation models of SAW devices are introduced,and the simulation of COM model is emphasized.Then,the chip fabrication of the device and the small-size packaging technology of CSP are deeply studied.On the chip,the fine inter digital lines are obtained by lift-off method,and the chip size is reduced by high reliable bridging process.The metal electrode uses Ti in the bottom layer and Cu-doped alloy process to improve the adhesion and power tolerance of the metal electrode.In package,the chip is tightly combined with HTCC substrate by gold ball welding and sealed by injection molding process,so that the device can achieve good reliability.At last,according to the industry standard,the electric performance and reliability of the device are tested in all directions.Finally,the correctness of the product design model and process design scheme is verified by the test results. |
PDF Full Text Request