New Structures and Improvements of Power Devices for Increasing Power Converter Efficiency

• Main Authors: Chorng-Wei Liaw, 廖崇維
• Other Authors: Chrong Jung Lin
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/25932921665464460743

博士 === 國立清華大學 === 電子工程研究所 === 95 === The disaster caused of greenhouse effects of the earth is becoming more obvious, the development of the green energy has been already in the whole world. Outside increasing income in new energy, reducing expenditure can reduce the emission of the carbon dioxide greatly too. Improve power converter efficiency and reduce stand-by power loss are the subjects that engineers are hard working to do. On this subject, the technology of the semiconductor is playing a very important role. This dissertation focuses on the improving and creating of the power devices characteristics to increase whole power converter efficiency. Utilize knowledge of systematic structure to carry on the improvement of the power device structure in order to achieve the energy-conserving purpose. Based on the original technology, we won’t need to change any process step to complete the device design. We can only design the layout of the devices in the original processes; it is very great to apply the devices into the applications in a short time without long developing schedule of a new semiconductor process technology. In the first part, a high voltage JFET is used to be a start-up device. With this device, the stand-by power dissipation can be reduced. In the second part, a trench termination is designed to simplify the process of a low voltage trench power MOSFET. Two solutions for improving the on-state resistance of trench power MOSFET in Li-ion battery protect are provided in the third part. By new cell structure and new device structure design, the on-state resistance can be reduced and the back side metal can also be removed. In the last part, the voltage spike of buck converter is discussed. Several designs of power MOSFET are used to verify the point.