显微红外测温中功率器件的边缘效应及其修正

Edge Effect of Power Devices and the Correction in the Infrared Micro-Thermography

针对显微红外热成像中对功率器件进行测温时边缘效应引起的测温误差,提出了采用精密位置调节装置进行修正的方法。分析了显微红外测温中边缘效应产生的原因,认为热膨胀等因素造成了被测功率器件表面两种不同发射率的材料与显微红外热像仪相对位置发生改变,并在两种材料的边缘区域导致明显的测温误差。在理论分析的基础上提出了判断被测件与显微红外热像仪相对位置改变方向的方法,并用显微红外热像仪进行了实验验证。根据被测件表面不同材料的发射率以及测温误差的正负可以判断被测件位置改变的方向,采用精密位移装置补偿这一位置改变即可有效消除边缘效应引起的测温误差。

Aiming at the temperature measurement errors caused by the edge effect of power devices in infrared micro-thermography,a correction method using a precise position-adjusting implement was proposed.The causes of the edge effect in the infrared micro-thermography were analyzed.It is considered that thermal expansions or other factors caused the relative position change of two kinds of materials with different emissivity on the surface of the measured power device and the infrared microscope,which made apparent errors near the edge region of the two mateials.Based on the theoretical analysis,the way to determine the direction of the relative position change of the device under test(DUT)and the infrared microscope was proposed,and was validated using an infrared microscope.According to the emissivity of different materials on the surface of the DUT and positive or negative values of temperature measurement errors,the position change direction of the DUT was determined.Using a precise position-adjusting implement to compensate the position change can effectively eliminate the temperature measurement errors caused by the edge effect.