微结构片外弯曲测试装置及试样设计  

Design of Test Apparatus for Bending Micro-Structure and Test Specimens Made of Silicon

作　　者：冯永平[1] 罗华云[1] 

机构地区：[1]南昌大学科学技术学院,江西南昌330029

出　　处：《力学季刊》2016年第2期372-380,共9页Chinese Quarterly of Mechanics

基　　金：江西省高等学校教学改革研究省级课题(JXJG-14-28-10;JXJG-15-30-3)

摘　　要：硅是微电子机械系统(简称微机电系统)中最常见的功能结构材料,可靠性是制约硅微构件小尺度加工和大规模制造的瓶颈问题.为研究硅微构件的力学特性,本文开发了一套以压电驱动、微力测量、位移检测为核心组件的片外测试系统.设计了一种将四个弯曲测试梁集于一体的微结构,借助有限元方法确定其尺寸,并用理论方法验证有限元分析的合理性.本文着重确保了四个关键设计目标:一、每根测试梁最大应力应位于其与外框架结合处;二、未断裂测试梁的最大应力受其他梁的断裂的影响应足够小;三、各个测试梁的最大应力的差别应足够小;四、支撑梁的最大应力应明显小于测试梁.最后测试了试样的弯曲强度,实验加载曲线和有限元分析基本吻合,表明测试装置和试样设计是合理的,为后续的硅微构件可靠性测试奠定了基础.Silicon based micro-structures have been extensively used in the area of micro-electro- mechanical systems （MEMS）. Its development into smaller scale and massive production are seriously restricted by reliability issues. To study the mechanical properties of silicon microstructures, an off-chip test device is designed, mainly consisting of piezoelectric drive, force sensor and displacement sensor. Secondly, a microstructure for bending test is designed, on which four test beams are integrated. The size of the structure is determined with finite element （FE） analysis. The rationality of FE analysis is verified through theoretical method. Four main objectives regarding the usability are ensured. 1） The maximum stress of each test beam should be located at the joint between the beam and the supporting frame; 2） The fluctuation of the maximum stresses of the unbroken test beams should be small enough when the other beams fracture; 3） The difference between the maximum stresses of the test beams should be small enough; 4） The maximum stress of supporting beams should be obviously larger than that of test beams. Thirdly, the bending strength of the specimen is tested. Loading curves of experiment and finite element analysis are almost consistent, indicating that the design of the device and the structure is reasonable. This research has laid the foundation for the follow-up reliability tests of the silicon micro-structures.

关 键 词：微机电系统 弯曲测试装置 硅微结构 试样设计 有限元分析 

分 类 号：TB301[一般工业技术—材料科学与工程]