Research On Transient Straight Through Model And Key Technologies Of High Voltage IGBT Power Module

As an important branch of power semiconductor device, power module is widely applied in many fields such as industrial control, rail transit, wireless communication and consumer electronics due to its excellent performance, high reliability, compact structure and low cost. In recent years, with the development of power semiconductor technology, power module technology has also been substantially improved and developed rapidly, and becomes one of the key technologies of power semiconductor field. Presently the power module has been deeply researched by domestic and foreign researchers, but it still faces many challenges in power module reliability, integration and reducing power loss.This dissertation researches on transient straight through model and key technologies of high voltage IGBT(Insulated Gate Bipolar Transistor) power module. Combined with engineering projects and according to the principal technology difficulties during research and development, researches are mainly focused on dv/dt transient straight through, di/dt transient negative voltage, high integration and reducing power loss. The high voltage IGBT dv/dt transient straight through model is proposed, the key technologies of high integration and low power loss of power module are also proposed. Three-phase inverter high voltage IGBT power module, high integrated high voltage IGBT power module and low power loss high voltage SiC(Silicon Carbide) power module are proposed and developed, two of them are mass-produced. The concrete research contents and innovations are shown as follows:1. High voltage IGBT dv/dt transient straight through model is proposed. For the straight through failure problem of three-phase inverter high voltage IGBT power module when working in system, the relationship between IGBT gate spike voltage with dv/dt, gate drive resistance RG, parasitic capacitances CGC, CGE and parasitic inductance LS is analyzed theoretically and analytic expression is derived. Additionally, the high voltage IGBT dv/dt transient straight through model is obtained. Based on dv/dt transient straight through model and experimental analysis, the relationship between dv/dt with safe operating area of high voltage IGBT is researched and summarized. Meanwhile, the key sub circuits of the power module such as bootstrap and protection circuits are analyzed and designed by taking into account of the compromise among circuit performance, reliability, implementation difficulty and cost. For the di/dt transient negative voltage problem that induced when three-phase inverter high voltage IGBT power module driving the inductive load, the mechanism and suppression method are analyzed in detail. Based on the deep trench dielectric isolation thick film SOI(Silicon-On-Insulator) process technology, a high reliability high voltage IGBT gate driver integrated circuit is proposed, the high side floating channel of this device can work at high voltage up to 650 V through bootstrap circuit. Experimental results show that this device can offers an improved immunity to di/dt induced substrate noise and be able to withstand di/dt transient negative voltage undershoot down to-50 V which is about 1.5 times of the conventional Si high voltage IGBT gate driver integrated circuit, thus delivers higher reliability. Furthermore, it needs ultra-low quiescent supply currents while offers source and sink output currents drive capacity of typically 200 mA and 300 mA respectively. The typical turn on and turn off delay times are 460 ns and 440 ns respectively. The typical rise and fall times are 90 ns and 65 ns respectively. An aluminum substrate structure three-phase inverter high voltage IGBT power module is proposed and mass-produced in the cooperative enterprise. The qualification rate of this power module is raised from approximately 70% in trial production period to approximately 98% in mass production period.2. Two kinds of high integrated high voltage IGBT power modules are proposed and developed. In order to further increase the integrated level and power density of high voltage IGBT power module, reduce system volume and simplify motor drive design, two kinds of high integrated high voltage IGBT power modules are proposed and developed. Taken system performance and complexity into consideration, based on boost main circuit topology and average current control mode, a PFC(Power Factor Correction)-integrated power module is proposed which can realize dual functions of power factor correction and power inversion. In order to reduce the soldering void rate of IGBTs in three-phase inverter of PFC-integrated power module, a four-corner-arc process technology is proposed. By this technology the soldering effect of IGBTs is effectively improved. Compared with conventional process technology, the void rate can be reduced by appropriately 10%. This PFC-integrated power module is successfully mass-produced in the cooperative enterprise. The dimensions of the module are 62 mm by 25.3mm by 5.5mm which achieving appropriately 15% volume reduction when compared with conventional scheme that has the same function. In addition, a digital double-driver power module which based on high and low voltage separated structure is proposed. This power module integrated rectifier, PFC circuit, compressor three-phase inverter, fan three-phase inverter, drive circuits, control circuits and protection circuits thus can realize a high integrated motor drive solution. The separated structure is adopted by the high voltage power circuit and low voltage control circuit of the power module and the half-molded packaging type is utilized by the high voltage power circuit which can reduce the interference and improve the heat dissipation capability effectively. The dimensions of the module are 115 mm by 77 mm by 6mm which achieving appropriately 30% volume reduction when compared with conventional scheme that has the same function.3. Two kinds of low power loss high voltage SiC power modules are proposed and developed. Based on aluminum substrate structure, two kinds of low power loss high voltage SiC power modules, namely hybrid SiC power module and full SiC power module are proposed and developed to further reduce the power loss that is difficult to achieve by conventional Si high voltage IGBT power module. Through the research and analysis of one-phase two-wire(1P2W), three-phase three-wire(3P3W) and three-phase four-wire(3P4W) modes, the power test method for high voltage SiC power module is proposed. Experimental results show that the power of hybrid SiC power module is 3.5W~21.7W and that of full SiC power module is 2.2W~17W at different compressor frequencies from 10 Hz to 70 Hz. When compared with conventional Si high voltage IGBT power module, the power is reduced by 12.5%~25.5% and 32%~53% respectively.