Study Of An Automated Test System For Thermal Diffusivity Of Thin Films Based On AC Calorimetric Method

In recent years, it becomes more and more important to know the thermophysical properties of the materials in special dimensions in the MEMS area. Thereupon a new subject— micron/nanoscale heat transfer was introduced. The same as the traditional subjects, experiment is the basic research means. The theoretical analysis and measurement of the thermophysical properties, especially the thermal diffusivity of thin films have become a focus in this field.First, this thesis introduced the definition of thermal diffusivity and the micro-scale effect of thin films. Next, the advantage and disadvantage of several testing methods for thin films were comparatively discussed. Then the principle of AC calorimetric method and its experiment technology were described in detail.Based on the theoretical discussion above, hardware and software of an automated test system for thermal diffusivity of thin films based on ac calorimetric method were designed and constructed. A motion controller connected with a personal computer was used to control an ultrasonic piezo-ceramic motor to realize precise localization. A programmable lock-in amplifier collected the temperature response from a micro thermocouple attached on the films and transmitted data to the computer through a GPEB(General Purpose Interface Bus) card. The software of the test system was designed by using OOP(Obejct Oriented Programming) method and the VC6.0 programming tool to set up GUI(Graphic User Interface). Last, the application of the test system was described and the measurement results were presented.