微力感測器的設計與製造

Abstract

微機電系統是近來熱門的研究領域之一，在本篇論文中，我們利用半導體製程技術來製造微力感測器。此微力感測器的原理乃利用壓電電阻材料的特性，因為他的電阻會隨著加諸在其上的應力而改變，兩者之間有一比例關係，所以我們設計一個機構包含有八根桿件在兩骨架之間，且在這八根桿件的些特定位置加上壓電電阻材料。當中間骨架受到不－同的力時，八根桿件會有不同的應力狀態，而使八根桿件上的壓電電阻材料的電阻產生改變。我們可藉由惠斯登電橋電路的電壓輸出來量測這些電阻的改變量，而求得機構所受的力，所以空間中六個自由度的力，可藉由量測六個以上壓阻變化來求得。 電腦分析也將應用於此感測器的特性分析，我們可以了解此感測器的靈敏度及尺寸誤差所造成的影響。在製程方面，我們考量每一製程步驟的特性和限制作出可行設計且可製造的微感測器。

In this thesis, we present a micro force sensor fabricated by the standard IC technology. The micro force sensor based on using the piezoresistant material as a variable resistance. Because its resistance change is directly proportional to the stress applied on it. We design a structure has eight beams between the hub block and low frame, and dope the piezoresistant material into the special regions of the beams to form eight resistors. When the hub block is under different forces, there are different stresses on the eight resistors which produce the different resisitance changes. According to the measurement of resistance changes, we can obtain the magnitude and the direction of the applied forces. And the resistance changes of the resistors can be converted into the output voltage by using Wheatstone bridge circuit. Therefore, we can measure resistance changes of six or more resistors to distinguish the spacial 6-d. o. f. forces. Numerical analysis is applied to simulate the behavior of the microsensor. We can realize the sensitvity of the microsensor and the effec of dimension error by using the software ANSYS53. In the manufactring process, we consider the characteristics and restrictions of each process to design a feasible and producible microsensor.