In today's era of rapid development in electronic technology, various electronic devices are constantly moving towards miniaturization, lightweighting, and high performance. As the core power supply component of electronic devices, the miniaturization of power modules has also become an inevitable trend. To achieve the miniaturization of power modules, a series of key technologies have emerged, and mastering these technologies is crucial for the research and development and production of power modules.
High-efficiency circuit topology technology
Application of novel topologies
Traditional power supply circuit topologies have limitations in achieving miniaturization, while novel circuit topologies offer possibilities for power module miniaturization. Interleaved parallel topologies are widely used in switching power supplies. Taking DC-DC converters as an example, interleaved parallel Buck converters reduce input current ripple by having multiple switches operate alternately. This allows for the use of smaller inductors and capacitors at the same output power, effectively reducing the size of the power module. Compared to traditional single-channel Buck converters, interleaved parallel Buck converters can significantly reduce inductor size and weight when handling high power, meeting the power requirements of space-constrained applications such as smartphones, tablets, and other portable electronic devices.
Integration of soft switching technology
Soft-switching technology is a crucial means of achieving miniaturization and high efficiency in power supply modules. Zero-voltage switching (ZVS) and zero-current switching (ZCS) technologies reduce losses during the switching process and decrease the heat generated by the switching transistor. In traditional hard-switching circuits, the switching transistor incurs significant switching losses during turn-on and turn-off, which not only reduces power efficiency but also requires larger heat dissipation devices, increasing the size of the power supply module. Soft-switching technology significantly reduces switching losses by making the voltage across the switching transistor zero before turn-on (ZVS) or the current flowing through the switching transistor zero before turn-off (ZCS). This allows for the use of smaller switching transistors and heat dissipation components for the same power output, contributing to miniaturization. In some high-end server power supply modules, the adoption of soft-switching technology has not only improved power efficiency but also reduced the module size by approximately 20%.
Advanced power device technology
Application of new semiconductor materials
The emergence of novel semiconductor materials such as silicon carbide (SiC) and gallium nitride (GaN) has revolutionized the miniaturization of power modules. Compared to traditional silicon-based power devices, SiC and GaN exhibit higher breakdown electric field strength, lower on-resistance, and higher electron mobility. For example, GaN power devices switch several times faster than silicon-based MOSFETs while maintaining lower on-resistance. In power modules with the same power rating, using GaN devices can significantly reduce the size of the switching transistors and lower the requirements for heat dissipation. In some fast chargers, the adoption of GaN power devices has resulted in a substantial reduction in charger size while achieving higher charging power and faster charging speeds.
Power device integration
The integration of power devices is also a key technology for miniaturizing power modules. Integrating multiple power devices onto a single chip reduces the number of external connections and discrete components, lowers parasitic parameters, and increases power density. Intelligent power modules (IPMs) integrate power switches, drive circuits, and protection circuits. In power modules for industrial motor drives, using IPMs not only simplifies circuit design but also reduces module size and weight, improving system reliability and stability.
Miniaturized magnetic component technology
Applications of high permeability materials
Magnetic components occupy a significant portion of the space in power supply modules; using magnetic materials with high permeability can effectively reduce their size. Nanocrystalline soft magnetic materials possess extremely high permeability and low-loss characteristics. In the transformers and inductors of switching power supplies, using nanocrystalline soft magnetic materials to fabricate the cores can significantly reduce the core volume while maintaining the same inductance and power. Compared to traditional ferrite cores, the volume of nanocrystalline soft magnetic material cores can be reduced by approximately 30%–50%, which is of great significance for achieving miniaturization of power supply modules.
Novel Magnetic Component Structure Design
In addition to material improvements, novel magnetic component structural designs also contribute to size reduction. Planar transformers, with their flat winding structure, offer better heat dissipation and a smaller size compared to traditional three-dimensional transformers. Planar transformers can be directly integrated onto printed circuit boards (PCBs), reducing space requirements. In some high-density power modules, the application of planar transformers has significantly reduced module thickness, enabling more compact designs.
Innovative packaging technology
Advanced surface mount packaging technology
Surface mount packaging (SMT) technology is fundamental to the miniaturization of power modules. With continuous advancements in electronic manufacturing technology, SMT packages are becoming increasingly smaller and more precise. The widespread use of small SMT capacitors and resistors, such as 0402 and 0201, in power modules significantly reduces circuit board area. Simultaneously, SMT technology improves production efficiency and soldering reliability, while reducing production costs. In some miniaturized power modules, the adoption of advanced SMT technology has resulted in an overall size reduction of approximately 40%.
System-in-Package (SiP) technology
System-in-Package (SiP) technology integrates multiple chips and passive components with different functions into a single package, achieving a higher degree of integration. In power modules, SiP technology can integrate power chips, control chips, inductors, capacitors, and other components to form a complete power system. This packaging method not only reduces the size of the power module but also shortens the signal transmission path, reduces signal interference, and improves the performance of the power module. In the power management modules of some high-end smartphones, the adoption of SiP technology has significantly reduced the size of the power module while improving the phone's battery life and charging speed.
Miniaturization of power modules is an inevitable trend in the development of electronic technology, and efficient circuit topology technology, advanced power device technology, miniaturized magnetic component technology, and innovative packaging technology are key to achieving this goal. Mastering these technologies not only meets the demand for miniaturized power modules in electronic devices but also drives continuous innovation in the performance, functionality, and application scenarios of electronic devices. With continuous technological advancements, future power modules will develop towards smaller size, higher power density, and higher performance, providing stronger power support for the development of electronic devices. Continuously focusing on and applying these key technologies in the research and development and production of power modules is of great significance for enhancing product competitiveness and promoting industry development.
