微米尺度下键合强度的评价方法和测试结构

Technique and Structure for Testing Bonding Intension in Micron Scale

在MEMS器件的设计与加工过程中,键合技术是体硅工艺的一项关键技术。由于MEMS器件的特点,其键合的面积通常是在微米到毫米量级内,传统测试键合强度的方法不再适用,该尺度下键合强度的测试与评价成为MEMS工艺测试的难点之一。文章提出了一种新型的测试结构,对面积为微米量级下键合的最大抗扭强度进行了测试。实验设计一系列的单晶硅悬臂梁结构测试键合面积在微米量级时的最大剪切力,键合面为常用的正方形,其边长从6μm到120μm,计算得出的剪力与采用实体单元有限元分析结果计算出的作用力相对误差为4.9%,这一误差在工程中是可以接受的。实验得出最大剪切扭矩和相应的键合面积的曲线。MEMS器件的设计人员可以根据结论曲线,针对所需的抗扭强度设计相应的键合面积。

In the design and fabrication of MEMS devices, MEMS fabrication process based on Silicon is a main technology, to which is deeply paid attention by researchers and industries. Because of the characters of MEMS devices, its bonding area is from micro area to milli-area, thug traditional methods to test bonding strength are not sufficient any more. Measuring the strength of that scale has become the choke point for MEMS development. We first defined a new way, a series of single crystal cantilever beam was taken to test max shear stress of bonding strength in micro area.,the square bonding profile length from 6μm to 120μm, the calculated lateral shear forces that cause a lateral displacement of 1 micro at the free end are comparable from theory and solid element, the relative error is about 4.9% and this error is acceptable in engineering. Experimental results obtain a curve of torsional strength versus the bonding area, and the designer can use it to determine the bonding area according to the required torque for their MEMS devices.