光学 精密工程, 2019, 27 (1): 137, 网络出版: 2019-04-06
MEMS热电堆芯片固晶工艺参数的优化
Optimization of die bond process parameters of MEMS thermopile chip
MEMS热电堆芯片 温度检测 压力参数 点胶高度 贴片高度 Micro Electro Mechanical System(MEMS) thermopile c temperature detection pressure parameters dispensing height patch height
摘要
MEMS热电堆传感器能够实现对温度的精确测量, 固晶工艺是其中关键一环, 但目前尚缺乏有效方法精确优化MEMS热电堆固晶工艺参数。本文介绍了热电堆传感器的工作原理, 提出了对固晶工艺参数(固晶厚度和爬胶高度)的要求。以固晶工艺要求为导向, 初步探究了压力参数对固晶工艺的影响并进行了压力参数的优化。在优化的压力参数下, 实验探究了点胶高度和贴片高度对固晶工艺的影响, 并缩小了两参数的选择范围。在此基础上, 通过有限元ANSYS软件, 分析在相同温度下, 不同固晶厚度的银浆与芯片接触处的热应力分布, 找出最佳的固晶厚度参数, 并精确优化了点胶高度和贴片高度。最后, 通过实验验证的方式, 对此参数下的MEMS热电堆固晶强度给出了检测结果。结果表明: 压力参数为0.3 MPa、点胶高度为140 μm、贴片高度为460 μm时, 固晶推力均值为43.14 N。其固晶质量最好, 能够满足固晶强度要求, 有助于提高MEMS热电堆芯片封装的可靠性与成品率。
Abstract
The die-bonding process is one of the key steps to ensure accurate temperature measurement by MEMS thermopile sensors. However, there remains no effective method to accurately optimize the process parameters of MEMS thermopile die-bonding. In this paper, the working principle of the thermopile sensor was introduced, and the requirements of the die-bonding process parameters-thickness and fillet height were proposed. Guided by the die-bonding process requirements, the influence of the pressure parameters on the process was initially explored, and the pressure parameters were optimized. Under optimized pressure parameters, the influence of the dispensing height and patch height on the die-bonding process was explored, and the range of choices for the two parameters was narrowed. On this basis, the finite element software package ANSYS was used to analyze the thermal stress distribution of different silver paste and chip thicknesses at the same temperature to determine the optimal die-bonding thickness and accurately optimize the dispensing height and patch height. Finally, through the experimental verification method, the test results were given for the die-bonding strength of MEMS thermopiles under these parameters. The experimental results indicate that when the pressure is 0.3 MPa, the patch height is 460 μm, and the dispensing height is 140 μm, the MEMS thermopile chip achieves average solid crystal thrust of 43.14 N. These parameters ensure the highest quality of the solid crystal, satisfy the die-bonding strength requirements, and help improve the reliability and yield of MEMS thermopile chip packages.
陈立国, 姜勇涛, 倪灯塔, 王敏锐, 孙立宁. MEMS热电堆芯片固晶工艺参数的优化[J]. 光学 精密工程, 2019, 27(1): 137. CHEN Li-guo, JIANG Yong-tao, NI Deng-ta, WANG Min-rui, SUN Li-ning. Optimization of die bond process parameters of MEMS thermopile chip[J]. Optics and Precision Engineering, 2019, 27(1): 137.