Packaging Innovations Drive the Growth of Power Semiconductor Market
The power semiconductor market is experiencing a significant upswing, driven by the increasing adoption of electric vehicles and renewable energy sources. As power densities continue to rise, packaging plays a crucial role in enabling more efficient power supplies, faster conversion, and increased reliability. The shift towards higher power densities and faster switching frequencies necessitates the use of advanced materials for substrates, die attach, wirebonding, and system cooling. This article explores the latest developments in power semiconductor packaging and their impact on the industry.
The Role of Packaging in Advancing Power Semiconductor Technology
Advancements in silicon technology have made packaging increasingly important in power semiconductors. As Brian LaValle, director of Mid-Power Voltage MOSFETs at Infineon, highlights, packaging becomes more critical as silicon advancements progress. The packaging of power modules, offered in discrete packages and integrated modules, plays a crucial role in delivering competitive advantages to manufacturers. Common packaging options include through-hole packages like TO-247 and TO-220, as well as surface-mount components like D2PAK, DPAK, SO-8, and leadless (TOLL), PQFN, and CSPs.
Enhancing Performance with Topside-Cooled SMT
Topside-cooled surface-mount technology (SMT) offers lower thermal resistance and improved switching performance. By connecting the drain tab directly to the heat sink, topside-cooled SMT reduces thermal resistance and improves switching performance. Additionally, an exposed source tab flush with the heat sink can enhance device current capability. Effective thermal management through single- or dual-sided cooling, as well as multi-die integration in framed or molded modules, contributes to overall solutions.
The Popularity of Power Quad Flat No-Lead (PQFN) Packages
The power quad flat no-lead (PQFN) package has gained popularity due to its compact size, low parasitics, excellent thermal performance, and compatibility with GaN. PQFN packages offer various multi-die, multi-clip, and wire variations, making them a versatile choice. They also feature lead-free plating, halogen-free mold compound, wettable flanks for automotive applications, and dual heat sink options. Amkor, one of the leading companies in power semiconductor packaging, provides SiC-compatible processes, including volume SiC dicing, heavy gauge wirebonding, and testing and burn-in services.
Driving Factors and Applications of Power Semiconductor Packaging
Power devices, such as transistors and diodes, are crucial for controlling and adjusting power in electronic systems. The push towards net-zero emissions is expected to double the power semiconductor market from $22 billion in 2022 to $44 billion by 2026. Applications for power devices range from transportation and power grids to energy storage, computing, 5G infrastructure, chargers, and industrial drives. The market for new power packaging accounts for 20% to 25% of the total semiconductor power market.
The Shift towards SiC and GaN Power Devices
The transition from silicon MOSFETs and IGBTs to silicon carbide (SiC) and gallium nitride (GaN) power devices is driven by their wide bandgaps, enabling higher switching power characteristics, higher operating frequencies, and lower resistance. Efficiency is crucial in smart power applications, while automotive applications prioritize minimal power losses. SiC devices, with their higher operating temperatures and price parity with silicon systems, have become the material of choice for electric vehicle applications.
Overcoming Challenges in Power Device Packaging
Power devices face challenges related to package inductance, electrical resistance, and mechanical stress. Mismatched coefficients of thermal expansion (CTE) between different materials can cause mechanical stress, especially at high operating temperatures. The replacement of silicon IGBTs with SiC MOSFETs in automotive inverters requires changes in assembly and packaging, including heavy-gauge wirebonding, copper clips, silver sintering, and more conductive molding compounds. Innovative techniques like thermal laser separation (TLS-Dicing) are being developed to mechanically separate SiC chips.
Lightning-Fast Switches and Power Device Operation
Power electronics rely on power conversion switches to manage and reduce fuel consumption and emissions. Power devices, such as MOSFETs and IGBTs, can be discrete or integrated modules. Losses, including conduction and switching losses, are inherent in power device operation. As power densities increase, insulating materials and interconnecting approaches must be designed to ensure systems operate within specifications.
Embedded Substrate Approaches for Minimizing Parasitics
Embedded die substrates offer a solution for minimizing parasitics in power devices. By integrating power devices and passive components in a substrate, with shorter interconnects and copper vias, electrical and thermal resistance can be reduced. Embedded technology provides surface mount integration and flexible routing solutions, resulting in lower power loss and improved electrical and thermal performance.
Conclusion:
Power semiconductor packaging is undergoing significant advancements to meet the increasing demands of electric vehicles and renewable energy sources. The adoption of SiC and GaN power devices, along with innovations in materials and assembly techniques, is driving the development of more efficient and reliable power systems. As the industry continues to evolve, packaging will play a crucial role in enabling higher power densities, faster switching frequencies, and improved overall performance in power electronics applications.
Leave a Reply