The Research On Application Of Microwave And LED Devices By Thermal Resistance Test Techniques

With the continuous development in integration, frequency, operating voltageand power density, the operating temperature rise in active region of semiconductordevices increases badly which can lead to serious reliability problems. For this reason,higher and higher requirements have been put forward to thermal design of powerdevices. Thermal management is applied throughout design, packaging and reliabilityevaluation process of devices. Therefore, accurate, noninvasive and convenientmeasurement technology of active region temperature rise for semiconductor devicesis an emergent problem for both scientific research and industry application.In this thesis, the thermal resistance measurement technology and power cyclingtest of GaAs high electron mobility transistors (HEMTs) and light emitting diode(LED) are deeply investigated by electrical temperature sensitivity method. Theresearch work includes the following aspects:1. Based on the existing technology, HEMT and LED thermal resistance testinstrument has been redesigned and optimized. The measurement precision andperformance parameters have been improved. The51microcontroller of controlcircuit was replaced with FPGA, which greatly enhanced the flexibility of design.Board of gold finger structure was replaced with SMT single boards, which simplifiedthe design and reduced the noise.2. Software of measurement instrument has been redesign and rewritten, whichincluding algorithm optimization of data extracting, data fitting, Foster-Cauer modeltransformation etc. Besides, redrawing of non-client area and button controls, datadrawing and auto-saving have been implemented by MFC application program, sothat all the operation can automatically complete from start of measurement to datasaving by clicking a button.3. LED power cycling experimental equipment and thermal resistancemeasurement are integrated by innovated design. Power cycling test of12LED chipscan work simultaneously. All the processes are also realized automatically, whichreduced the difficulty and intensity of operation, and improved the working efficiency.The target of Guangdong Strategic Emerging Industry Project has been completed.