Table Paste-type Power Mosfet Packaging Technology

SMD type power MOSFET is one of the most important electronic components in a surface mount circuit. With the electronics manufacturing industry and the rapid development of electronic information industry, small size, miniaturized semiconductor devices have increasingly become the focus of the development of modern electronic technology, The semiconductor device manufacturers discrete devices on the power structure of the new package is also increasing emphasis on research and development. As the demand for electronic products and the increasing requirements of energy efficiency, power device market in China has maintained rapid growth rate, SMD on the increasingly urgent demand, the development of such devices has become a priority. The project comes from YongGuang Electronics Co., Ltd. China Zhenhua Group SMD type power MOSFET packaging technology and applications. The purpose of the research is to SMD-type power MOSFET packaging technology research and applied to production and eventually replace foreign with the models.This paper is to address the problem, to 1N60-type surface-mount type power MOSFET packaging technology as the main object of study, in depth analysis of the packaging and the use of the failure mechanism based on the impact of product quality and reliability to identify the key problem, material, package structure, and made an innovative packaging technology and exploration research. The main contents are: 1. A detailed study of die bonding holes thermal properties of the device. Die bonding process using soft solder, the main problems is the die bonding holes. Holes existence of a certain size, easy to die bonding area have a greater contact resistance, resulting in local temperature, leading to device failure by overheating the role of stress.To solve this problem, researchers used new diversion technology to reduce the holes.2. Detailed study of the device wire bonding process on the damage and failure mechanism of the device. Wire bonding process using ultrasonic aluminum wedge of cold welding technology, the main difficulty is to prevent the crater. Crater was caused in the bonding process under the aluminum layer of semiconductor material damage and left holes in the MOSFET,it's a direct result of physical breakdown and failure. After much analysis of the failure of the device and found that the factors leading to the crater appears, Therefore, the study raised crater wire process control technology.3. Detailed study of the welding temperature led to 1N60 Chip fracture failure mechanism. Welding method in accordance with the normal use,the failure of the device appear broken chips up to 10% to 70% range. Through the device failure analysis and research to find a good thermal match the design.