一种CMOS驱动器的晶圆级芯片尺寸封装

Wafer Level Chip Scale Packaging for CMOS Drivers

采用晶圆级芯片尺寸封装(WLCSP)工艺完成了一款小型化CMOS驱动器芯片的封装。此WLCSP驱动器由两层聚酰亚胺(PI)层、重分配布线层、下金属层和金属凸点等部分构成。完成了WLCSP驱动器的设计,加工和电性能测试,并且对其进行了温度冲击、振动和剪切力测试等可靠性试验。结果表明,经过晶圆级封装的CMOS驱动器体积为1.8 mm×1.2 mm×0.35 mm,脉冲上升沿为2.3 ns,下降沿为2.5 ns,开关时间为10.6 ns。将WLCSP的驱动器安装至厚度为1 mm的FR4基板上,对其进行温度冲击试验及振动试验后,凸点正常无裂痕。无下填充胶时剪切力为20 N,存在下填充胶时,剪切力为200 N。

A miniaturized CMOS driver chip was packaged based on the wafer level chip scale packaging（ WLCSP） technology.The WLCSP driver consisted of two polyimide（ PI） layers,redistribution layer,under bumping metallization layer and metallic bumps.The design,processing and electrical performance testing of the WLCSP driver were completed.And its reliability tests such as temperature cycling,vibration and shearing force tests were completed.The results show that the volume of the waferlevel packaged CMOS driver is 1.8 mm × 1.2 mm × 0.35 mm,the pulse rise time is 2.3 ns,the fall time is 2.5 ns,and the switching time is 10.6 ns.The WLCSP driver was mounted on the FR4 board with the thickness of 1 mm.After temperature cycling and vibration tests,the bumps were normal without cracks.The shearing forces are 200 N and 20 N with and without underfilling encapsulant,respectively.