Fabrication of a silicon based vertical sensitive low-g inertial micro-switch for linear acceleration sensing

Most of the MEMS inertial switches developed in recent years are intended for shock and impact sensing with a threshold value above 40 g. These switches were designed as lateral sensitive and were fabricated using either electroplating or silicon micromachining technology. Considering on the other hand the low-g micro-switch (threshold value <10 g), usually consists of a high volume proof mass and a low stiffness spring, were rarely reported because these switches were less practical to be fabricated with lateral sensitive structure design. In this paper, we report on a silicon based vertical sensitive low-g inertial switch designed for linear acceleration sensing. The inertial switch consists of a cylinder shaped proof mass, suspended by circular shaped spiral spring. The fabrication process is based on a customized symmetrical double-buried layer SOI wafer with standard silicon micromachining. The centrifugal experiment results show that the threshold value is around 5.5 g which is close to the designed value.

[1]  Slava Krylov,et al.  Meso scale MEMS inertial switch fabricated using an electroplated metal-on-insulator process , 2014 .

[2]  Cao Yun,et al.  A novel MEMS omnidirectional inertial switch with flexible electrodes , 2014 .

[3]  Miao Yu,et al.  Latching in a MEMS shock sensor: Modeling and experiments , 2010 .

[4]  Kwanghyun Yoo,et al.  Development and characterization of a novel configurable MEMS inertial switch using a microscale liquid-metal droplet in a microstructured channel , 2011 .

[5]  Hong Wang,et al.  Influence of applied acceleration loads on contact time and threshold in an inertial microswitch with flexible contact-enhanced structure , 2014 .

[6]  Z. Yang,et al.  MEMS inertia switch with flexible CNTs/Cu composite array layer between electrodes for prolonging contact time , 2015, 2015 Transducers - 2015 18th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS).

[7]  Masayoshi Esashi,et al.  Acceleration switch with extended holding time using squeeze film effect for side airbag systems , 2002 .

[8]  Alejandro F. Frangi,et al.  Threshold shock sensor based on a bi-stable mechanism , 2013, 2013 Transducers & Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII).

[9]  Xuesong Liu,et al.  Design, fabrication and characterization of a latching acceleration switch with multi-contacts independent to the proof-mass , 2011 .

[10]  Byung Man Kwak,et al.  Snapping microswitches with adjustable acceleration threshold , 1996 .

[11]  David S. Epp,et al.  Development and calibration of a stochastic dynamics model for the design of a MEMS inertial switch , 2006 .

[12]  K. Najafi,et al.  Fabrication of vertical comb electrodes using selective anodic bonding , 2007, 2007 IEEE 20th International Conference on Micro Electro Mechanical Systems (MEMS).

[13]  Guifu Ding,et al.  The design, simulation and fabrication of a novel horizontal sensitive inertial micro-switch with low g value based on MEMS micromachining technology , 2013 .

[14]  Wei Ma,et al.  Design and characterization of inertia-activated electrical micro-switches fabricated and packaged using low-temperature photoresist molded metal-electroplating technology , 2003 .

[15]  Khalil Najafi,et al.  A wide-range micromachined threshold accelerometer array and interface circuit , 2001 .

[16]  Jungwook Choi,et al.  Deformable Carbon Nanotube-Contact Pads for Inertial Microswitch to Extend Contact Time , 2012, IEEE Transactions on Industrial Electronics.

[17]  Josef Binder,et al.  Additive electroplating technology as a post-CMOS process for the production of MEMS acceleration-threshold switches for transportation applications , 2000 .