The Application Of Low-temperature Sintering Of Nano-silver Paste In Manufacture Of IGBT Module

With the trend of electronic technology is increasing, the IGBT has become the crucial part within many devices, it also produces important effects on other's areas. As the development of high-power device is the major direction, the correlative of IGBT modules are thus became the dominated product in the electronic industry.The traditional IGBT module is based on soldering, it uses solder paste or performing solder film to have the solder-reflow and then melts and consolidates it as solder alloy to connect the chip and substrate within the power module. However, this approach is shortage of working life and temperature controlling. Moreover, because the solder's melting point is rather low, the peak of chip's junction temperature within this module is limited by 150℃. The recent approach of low temperature sintering of nano-sliver paste has a better performance on the interface connection compared the previous one, as it reduces the size of silver grain to nanometer level to achieve the low temperature sintering of nano-silver paste.Former studies of nano-silver paste have proved that it is achievable that implementing low temperature sintering of nano-silver paste technology on the connection within the single big chip based on earlier researches. However the thickness of chips are different from each other. In this dissertation, the possibility of implementing low temperature sintering of nano-silver paste technology on IGBT module has been researched.There are three sections about this dissertation:Firstly, it includes the method and technology of making IGBT pseudo-chip and pseudo-diode chip. This research has adopted two wafers on different thick levels to simulate IGBT and diode. The industry process is to incise silicon chip as the targeted size and to deposition by magnetron sputtering. The process of deposition is to deposit a layer of titanium and a layer of silver on it.Secondly, the research designates the electric circuit of module and DBC substrate. The DBC substrate with figures is made of based on LPKF Protolaser and etching machine. The principle of electric circuit design within the module have to symmetrical layout, so that the current can be even distributed in this module in order to design achieves maximum performance. Last but not the least, with the help of the sintering device designed by the researcher, this research has achieved the sintering of chips with different thickness on DBC substrate within one step.