The rapid growth of the advanced consumer 5G wireless mobile phones has propelled the demands of fabricating surface acoustic wave (SAW) filters with smaller size and high performance. Three-dimension wafer-level package (3-D WLP) for SAW filter is a promising solution to replace conventional surface mounted technology and chip-scale packaging. In this article, a new WLP for SAW filter with a size of 1.3 mm ×1.1 mm ×0.35 mm is developed using thin dry film capping. The new 3-D WLP significantly reduces the overall thickness which is particularly meaningful for low-profile smartphones and tablets. A number of key processes were developed. To improve the quality, finite element modeling (FEM) is used to simulate the mechanical stress to optimize cavity structure. Reliability tests were performed and the results indicated that there were no significant frequency response changes occurred and low insertion loss (IL) in pass band was less than 0.2 dB after pro-conditional level 3 test, unbiased highly accelerated stress (uHAST) test, and temperature cycling (TC) test on SAW filter packages. It can be concluded that 3-D WLP for SAW filter achieves miniaturization, good electrical performance, and reliability.

中文翻译：

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使用薄膜封盖的 SAW 滤波器 3D 晶圆级封装的开发和可靠性研究


先进消费类 5G 无线手机的快速增长推动了对制造更小尺寸和高性能的表面声波 (SAW) 滤波器的需求。用于 SAW 滤波器的三维晶圆级封装 (3-D WLP) 是替代传统表面贴装技术和芯片级封装的有前途的解决方案。在本文中，采用薄膜干膜封盖开发了一种用于 SAW 滤波器的新型 WLP，尺寸为 1.3 mm ×1.1 mm ×0.35 mm。新的 3D WLP 显着降低了整体厚度，这对于薄型智能手机和平板电脑尤其有意义。开发了许多关键流程。为了提高质量，使用有限元建模（FEM）来模拟机械应力以优化型腔结构。进行可靠性测试，结果表明，经过前条件3级测试、无偏高加速应力（uHAST）测试和测试后，频率响应没有发生明显变化，通带插入损耗（IL）低于0.2dB SAW 滤波器封装的温度循环 (TC) 测试。可以得出结论，用于SAW滤波器的3D WLP实现了小型化、良好的电气性能和可靠性。