The driving force behind the development of new products and technologies in the power electronics field stems from the growing market demand for higher power density, greater system integration, robustness, and higher reliability. This is accompanied by market demands for lower costs, standardized interfaces, flexible scalability, and modularity. In recent years, the focus in power electronics has been largely on the research, development, and upgrading of new high-power integrated circuits targeting specific markets. This has led not only to the emergence of standard IGBT modules but also to the development of specialized modules optimized to meet specific customer needs. Low-loss modules are optimized for reduced on-state voltage drop; however, due to their very high switching losses, they are only meaningful for applications with lower switching frequencies. Correspondingly, the industry has also developed ultra-fast modules for high switching frequencies. These IGBT modules are ideal for resonant switching converters due to their smaller tail current. Furthermore, next-generation power integrated modules offer higher power density and efficiency without changing module size. New channel IGBTs and soft punch-through IGBTs are the focus of future research in this area, further expanding the range of available module options. The current current density of modules composed of the latest generation of channel IGBTs and axial carrier lifetime controlled freewheeling diodes reaches 200 A/cm2 (Figure 1). Such a high current density makes the existing package size more efficient, that is, the chip area required for the existing current level will gradually decrease. For example, in 1999, the largest 1200V half-bridge module of SEMIKRON had a rated current of 400A, while today the same package can provide 600A of current. Due to the continuous increase in power density, manufacturers and power module users often face new challenges. Figure 1 Development of current density For some time now, the size of power converters has no longer depended on the size of power semiconductor modules, but on passive components such as capacitors, inductors and filters. This phenomenon is especially true for low power drivers, as can be seen from a research report of (1) ECPE (European Centre for Power Electronics). For modern drives below 2.2kW, the power semiconductor module package occupies only 6% of the total device volume, roughly equivalent to the volume occupied by cable terminals. The DC link capacitor bank occupies about 12% of the volume, twice that of the power devices. The largest component in terms of space is the control circuit board (approximately 23% of the volume), as it contains not only drive and control circuitry but also power supply units and EMI filters (Figure 2). This trend is extending to high-power conversion systems. Power electronic devices are becoming increasingly smaller, while the volume of passive components, cables, and main circuit terminals remains largely unchanged. Figure 2: Component/Volume Comparison of a Modern 2.2kW Drive. Today, the size of power devices no longer depends on the area occupied by semiconductor chips but on the main circuit terminals. Therefore, it is unrealistic to expect to reduce the size of power electronic modules to lower costs to the same extent as chip size reduction. Moreover, in the presence of vibration, large cable cross-sections and DC busbars can exert significant stress on the modules, which can even negatively impact the reliability of connecting components. Therefore, stress-relieving components and additional mechanical reinforcement components for DC circuit stages play important roles in the design of power converters. The increasing power density in semiconductor modules brings more and more heat dissipation problems to users. As module size decreases while power remains constant, the power loss per unit volume of the module gradually increases, placing higher demands on heat sinks. In forced air cooling systems, it is generally unlikely to utilize the module's maximum power for reliability reasons, and we do not recommend users increase the heat sink temperature. Therefore, to best utilize the heat sink, it is necessary to disperse heat sources to avoid hot spots. With the introduction of the SEMIKRON module, SEMIKRON has set a new benchmark: using a single half-bridge module instead of a monolithically integrated six-tube package module in power components. When using forced air cooling, modules can be spaced out. Due to the corresponding thermal conduction effect, the module substrate temperature is much lower, thereby increasing output power. Figure 3 illustrates the positive effect of heat dissipation; in this example, if modules are spaced out on the heat sink, the maximum heat sink temperature is reduced from 96°C to 91°C. Of course, an integrated six-tube package module can be used to replace the half-bridge module. In this case, if water cooling is used, a more compact solution with higher power density can be achieved. For some time, research has focused on developing new mounting and connection technologies to accommodate the use of new chips with increasing current densities. To date, no single technology has been able to achieve complete success due to limitations in reliability and flexibility. In addition, the development of new connection technologies is also driven by greater integration (drive circuits and passive components) and double-sided heat dissipation technology for module chips. Connection technologies have made great progress due to the use of multilayer circuit boards, metallized devices, soldered packages, and even curved circuit boards (2). It is only a matter of time before these highly integrated technologies are used in commercial power electronic modules. Product Platform Development In addition to the technical challenges mentioned above, product platforms also play an increasingly important role in the field of power electronics. The so-called product platform development here refers to the development of basic modules, which are platforms for developing or designing different product series. For example, when we see the same car engine and chassis components on different car models from the same manufacturer, it can be said that the automotive industry is a pioneer in implementing this "product platform" concept. Our customers are implementing the same strategy in converter development and production, but the problem is that their development efforts haven't received sufficient support from semiconductor manufacturers. There are too many inconsistencies in the different models and connection technologies of semiconductor modules currently on the market. As a result, it's difficult for customers to manufacture a variety of converter series with consistent performance based on standard components and modules. With the introduction of the SEMIX® product platform, SEMIKRON is committed to providing a solution for modules in the 15-150kW range to address this problem. Figure 4 illustrates the concept of the SEMIX® product platform. Based on a basic module, different module versions can be produced for different power ranges, topologies, integration levels, and package types, thus meeting the specific needs of individual users. The basic module itself has four different types of module packages for different current ratings and topologies. However, these four packages are based on the same internal component platform, meaning that the DC link and drive circuit interfaces are consistent throughout the entire power range. The introduction of SEMIX allows us to stock these standard product modules before production, enabling the rapid production and delivery of customer-customized products. For converter designers, this means simpler power and functionality measurement of module components, while also reducing development complexity and time. This allows for customized topologies and continuous extension of customer product lines. Further market demand is for optimized connections to power module peripherals, including short, adaptable main circuit terminals and driver IC connections. The SEMiX platform, for the first time, mounts driver circuitry directly on the power module, resulting in very short connection paths. Conclusion Thanks to advanced chip technology, modern power semiconductors offer approximately 50% higher current density compared to those of the past few years. This development directly increases the requirements for component integration and connectivity in power semiconductor modules, as well as device heat dissipation. For forced air cooling systems, various cost-reducing constraints have been overcome. Many existing chip technologies offer advantages tailored to specific applications, considering optimal forward conduction losses and high switching frequencies. With the introduction of the new SEMIX module series, SEMIKRON can offer a wide range of modular products to meet specific customer needs. The SEMIX product family will continue to be supplemented and expanded in the coming years. References: (1) Technology Study on Industrial Drives, 2004, ECPE (2) Flip-Chip Flex-Circuit Packaging for Power Electronics, Y. Xiao et al., CPES, ISPSD 2001