AlInGaP LED Stress Sensor and It’s Application on Package

• Main Authors: P.J.shen, 沈伯仲
• Other Authors: 張國雄
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/03026262858869701924

碩士 === 大葉大學 === 電機工程學系 === 98 === Piezo-resistors act as a stress sensors were made by dry etching through AlGaInP/GaAs LED epi-wafer. Three meander shaped stress sensors along [110] and [ 10] were made on P layers. Their resistances were approximately 40KΩ、140KΩ and 250KΩ respectively. External forces were exerted on a sensor strip. Four-point bending method was used to calibrate the resistance changes under both tensile stress and compressive stress. It was found that the resistance of stress sensor along [110] has an increment of 0.76-1.54% under tensile stress. Larger the tensile stress higher the resistance change. By contrast, the resistance of those stress sensors along [110] has the decrement of -1.12%至-0.59% under compressive stress. Again, larger the compressive stress higher the resistance change. After making a detailed calibration, stress sensor was mounted into SMD packaging. The stress type and quantity inside the SMD packaging is successfully measured.