Abstract: IGBT modules have been widely used in the power electronics industry. The development of systems increasingly demands higher power density, optimized electrical performance, higher reliability, and simpler installation methods for power electronic devices. Optimizing existing products while ensuring high reliability and compatibility has become the goal of power module development. Keywords: Thin package, stray inductance, IGBT module, reliability 1. Introduction IGBT modules based on the 94*34mm package have been widely used in many industries over the past decade. Since then, major companies have continuously launched their own module packaging forms while maintaining compatibility with this module size. Nanjing Yinmao Microelectronics has launched a 34mm thin, low-inductance module (hereinafter referred to as the T1 package). The T1 adopts a high power density design and selects the optimal IGBT and FRD chip combination according to the application requirements of different industries, making the new module have higher current output capability and lower peak turn-off voltage compared with traditional power modules of the same mounting size. Meanwhile, the solderless design of the power terminals greatly improves the reliability of the terminal connections under ambient temperature cycling and power cycling conditions, providing a foundation for improving system reliability (Figure 1 shows a comparison of the physical appearance and dimensions of the T1 module (left) and modules from other companies (right)). [b]2. Materials[/b] The shell of the T1 packaged module is made of high-strength material, and the terminal electroplating process is strictly controlled to ensure the robustness of the shell during long-term high-temperature use. A unique cover design ensures safety during use. [b]3. RoHS Process[/b] The new module's manufacturing process uses a lead-free process, and the terminals and DBC use a solderless process, making it a green product that meets RoHS requirements. [b]4. Solderless Terminal Process[/b] 5. Power Cycling Capability In the practical application of power modules, the reliability of the module is mainly affected by thermal stress. Changes in motor load (full load vs. light load) and inverter output frequency can all cause temperature variations. Different materials have different coefficients of thermal expansion, and brazing is prone to fatigue under thermal stress, leading to terminal detachment and failure. The T1 package utilizes ultrasonic bonding between the terminals and the DBC substrate, significantly improving the load cycling capability of the power terminals. (Figure 3 shows the power cycling capability of the module with soldered terminals and the T1 module under different case temperature changes.) 6. Novel Low-Inductance Power Terminal Design The T1 module's power terminals abandon the soldering connection to the DBC substrate, instead employing high-purity aluminum wire ultrasonic bonding, greatly reducing stress between them. By eliminating the traditional S-shaped design, the terminal length is reduced by 1/3, thereby reducing the module's parasitic inductance and terminal resistance. Compared to traditional 34mm package terminals, inductance is reduced by 30%, optimizing turn-off characteristics and reducing power consumption at the terminals during use. The new terminal design also reduces internal installation space. Because soldering is not required, the chip layout space on the DBC is effectively saved, resulting in a more optimized chip space layout and higher module current density. This balances the circuit design. The signal terminals utilize DBC routing and bonding technology, optimizing signal symmetry. Compared to traditional flying wire soldering, this simplifies the process and reduces gate parasitic inductance and resistance. (Figure 6 shows the internal terminal mounting structure of the T1 module.) 7. Switching Characteristics The new T1 package design introduces low-loss, fast, and standard IGBT modules suitable for various systems with different requirements, such as frequency converters, motor control, welding machines, induction heating, switching power supplies, and UPS. By testing the dynamic characteristics of the module at high temperatures, it was found that the new thin-terminal solderless packaging design significantly reduces the losses generated during the switching process of the device, optimizes characteristics such as RBSOA, and reduces voltage overshoot during turn-off. [align=center]Ch1:IC=30A/div;ch2:Vcc=200V/div; Figure 7. Comparison of turn-off characteristic waveforms of T1 package and standard package Tj=125℃[/align] Figure 7 shows the turn-off waveforms of two low-loss devices measured under the same test equipment and test conditions. From the figure, it can be seen that the voltage overshoot of T1 is △Vc1=180V; the voltage overshoot of DLC package is △Vc2=220V. Therefore, the following calculations are made: T1 package module: di/dt=72A/0.386us=187A/us △Vc1=L1＊di/dt L1=△Vc1/di/dt=180V/187A/us=960nH DLC package: di/dt=72/0.320us=225A/us △Vc2=L2＊di/dt L2=△Vc2/di/dt=220V/225A/us=978nH Under the same test conditions, the module inductance difference △L=978-960=18nH. [b]Frequency Characteristics[/b] The thin, low-inductance package design reduces the module's switching losses, and the optimized chip space layout reduces thermal resistance, ensuring the module has higher frequency current output characteristics. Figure 9 compares the effective output current of two low-loss IGBT modules at different switching frequencies. It can be seen from the figure that at the same frequency, the T1 module has a higher output current capability, leaving more margin for system designers. 8. New Packaging More Suitable for High-Frequency, Fast IGBT Modules In applications where switching frequencies exceed 20kHz, power devices are generally required to have excellent high-speed switching performance. However, as the systems using these power devices differ, the main circuits and control methods also vary. Often, not only is a high-speed chip on the module needed, but also optimized packaging and design at high frequencies. Therefore, the advantages of the T1 package are particularly prominent in high-frequency devices, providing greater current output capability for medical equipment and inverter welding machines. Testing the switching losses of the GF100HF120T1 at high temperatures shows that at Vcc=600V and IC=100A, Eon=8.5mJ, Eoff=5.2mJ, and the total switching loss is only 13.7mJ, resulting in better dynamic characteristics at high frequencies. Figure 11 compares the frequency output characteristics of three fast IGBT modules, demonstrating that the T1 module has the lowest temperature rise under the same current output conditions. 9. Optimized Installation Space To ensure better heat dissipation from the module and good contact between the substrate and the heat sink, the substrate is mechanically processed to form a curved surface, further guaranteeing proper contact during installation. The standard 80mm hole spacing allows users to install the module directly without altering the heat sink's mounting holes. The slim housing, only 21.5mm high, reduces the module's installation height for customer system designs, shortening the connection wires and copper busbars used for power terminals. There are no significant changes compared to traditional installation methods; the same installation sequence and operational requirements can be followed. Conclusion: Energy conservation, emission reduction, and full utilization of green energy are key to China's sustainable development. The miniaturization and intelligentization trends of various energy-saving devices increasingly demand that new power devices develop towards high power density, low heat loss, and high reliability. Nanjing Yinmao Microelectronics' T1 thin-package module reduces internal inductance and thermal stress, saving space for system designers. Furthermore, the chip technology designed according to specific applications maximizes the power module's efficiency.