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论文类型：期刊论文

第一作者：伍文杰

通讯作者：胡宸源,范继,涂良成

合写作者：刘丹丹,邱文瑞,刘骅锋,胡方靖

发表刊物：Journal of Micromechanics and Microengineering

收录刊物：SCI、SSCI

学科门类：工学

一级学科：电子科学与技术

文献类型：J

卷号：28

关键字：MEMS packaging, spacing control, sensitivity improvement, 3D electroplating, accelerometer

DOI码：10.1088/1361-6439/aae9cd

发表时间：2018-10-19

摘要：Capacitive micro accelerometers with high sensitivity have found wide applications in geophysics. Reducing the interelectrode spacing, which is determined by the thickness difference between the electrodes and the solder bumps in flip-chip utectic bonding, is an efficient way to improve the sensitivity of area-varying capacitive transducers in micro accelerometers. raditional methods require extra materials and processes, and precise control of the thickness of both the solder pumps and the electrodes is necessary. This work introduces a novel method for the precise control of the interelectrode spacing using a three dimensional (3D) electroplating process. Standoff pillars and electrodes are deposited by a single electroplating process with a constant thickness difference, which is only determined by the gap of the seed features that can be precisely determined by photolithography. The standoff pillars are used to define the thickness of the solder bumps in the packaging process. The 3D electroplating process is studied, characterized and applied to a typical high-precision micro capacitive area-varying accelerometer. Experimental results show that the variation of the interelectrode spacing is decreased by more than 6.5 times, when compared to that without the 3D electroplating process. Benefitting from the reduced interelectrode spacing, the ensitivity is increased by more than 3 times, while the resolution is 10 ng (√Hz)−1, which is 2.5 times better. It is believed that such a method can be applied to MEMS devices where interelectrode spacing needs to be precisely controlled.