Electrostatically actuated microswitches and relays have been developed at Northeastern University. These devices are approximately 100 x 100 microns in size and have been tested up to 10~9 cycles with a current of 2 mA per contact. In this paper we examine the thermal characteristics of a microswitch with Au-Au contacts. We describe a finite element model to study the temperature distribution in the microswitch. The modeling results show that the highest temperature is located in the thin film contact trace rather than at the contact interface. The hottest spot moves away from the contact if the contact radius increases. Measurements show a sharp decrease in the contact resistance at a switch voltage of about 0.08 V and a current of 0.15 A, which may be due to removal of surface contaminants or softening of the contact surfaces. The result is in rough agreement with the onset of softening predicted by the model. The contact trace melts at a switch current of 1 A. The melted region is 3.5-6 μm away from the center of the contact, slightly further than is predicted by the model.
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机译:东北大学已经开发出了静电驱动的微动开关和继电器。这些设备的尺寸约为100 x 100微米,并经过10至9个周期的测试,每个触点的电流为2 mA。在本文中,我们研究了具有Au-Au触点的微动开关的热特性。我们描述了一个有限元模型来研究微动开关中的温度分布。建模结果表明,最高温度位于薄膜接触迹线中,而不是接触界面处。如果接触半径增加,则最热的点将离开接触。测量表明,在约0.08 V的开关电压和0.15 A的电流下,接触电阻急剧下降,这可能是由于去除了表面污染物或接触表面变软所致。结果与模型预测的软化开始大致吻合。触点迹线在1 A的开关电流下熔化。熔化的区域距离触点中心3.5-6μm,比模型预测的距离稍远。
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