声表面波滤波器圆片级互连封装技术研究

Research on Wafer Level Interconnect Packaging Technology for SAW Filters

射频前端模块是无线通信的核心,滤波器作为射频前端的关键器件,可将带外干扰和噪声滤除以保留特定频段内的信号,满足射频系统的通讯要求。本文总结了声表面波滤波器工作原理及其传统封装技术,提出了一种圆片级互连封装技术,采用曝光显影、电镀及印刷等工艺实现了芯片焊盘上铜金属层和焊球的形成,避免了芯片核心功能区IDT的损伤。对封装前后电性及上基板可靠性测试,结果表明该封装方案满足声表面波滤波器封装需要。本技术在声表面波滤波器封装方面有广阔的应用前景,适用于批量生产。

The RF front-end module is the core of wireless communication.As a key component of the RF front-end,the filter can filter out-of-band interference and noise to retain signals in a specific frequency band to meet the communication requirements of the RF system.This paper summarizes the working principle of traditional packaging technology for SAW filter,and process development for a novel wafer-level packaging technology for SAW filter is presented.Through this technology,exposing process,developing process,electroplating process and printing process are operated before the wafer slice.The SAW filter formed copper pillar and solder ball on the pads,and did not damage the core functional area IDT.The electrical properties and the reliabilities were tested before and after packaging.The test results showed that the packaging solution satisfies SAW filter packaging needs.This technology has broad application prospects in the packaging of SAW filter,and is suitable for mass production.