On the weekend, I found a place to drink tea with Liu Zong and others, mainly talked about the development direction of the vehicle power supply, one of which is that OPC and DCDC will choose the plastic power module to replace the original discrete scheme. In other words, in the automotive sector, the trend toward modularization, from inverters to all the high-voltage power segments we see, is clear. According to Yole's analysis report, the MOSFET market is expected to reach $9.4 billion in 2026, the IGBT market is $8.4 billion, and the power module packaging materials market is expected to achieve a $3.5 billion market in 2026.
Figure 1. Market for power electronics and power packaging
Part 1
Power package
From the perspective of value differentiation, the largest market segment of power packaging materials is the substrate, followed by the substrate, and the next in line is the substrate mounting and chip mounting materials. Due to the growing demand, the shortage of the power device market has led to a change in the business model and the reshaping of the supply chain in the industrial chain.
From the current point of view, the original Tier 1 auto parts suppliers and car company OEMs have begun to be deeply involved in the design and manufacture of power modules. The power module packaging of semiconductor devices is an opportunity for system manufacturers and automakers to control upstream, because IGBT's power packaging technology is relatively mature, Tier1 suppliers and OEMs are more willing to start in the field of silicon carbide (SiC) MOSFET technology.
▲Figure 2: Iteration of power package
The chip shortage in 2021 has led Chinese automakers to hope for core power electronic components to be as localized as possible. Chinese companies develop power module packaging solutions and begin to use some local power chips, and the power chips provided by European, Japanese and American companies still account for a relatively large part.
▲Figure 3.SiC-based package, from the R & D point of view, there are some points that can be done
From a technical point of view, power module packaging technology is not only about lead bonding, soldering and packaging; packaging technology in the automotive field, in terms of power density, performance and reliability has strong requirements is more complex, requiring specific proprietary technology.
Figure 4: Typical failure of the power module
Part 2
Trends in power modules
From the perspective of the trend of technological development, Yole and the engineers of UMC have given a technological development trend, my understanding is that it is necessary to do a combing according to the choice of each car company, and the bet on a single company seems to be a little early. Around the temperature resistance, reliability, parasitic inductance, thermal resistance and cost of these elements, can be combined into a lot of system solutions.
▲Figure 5.Technical development trend of power module
Figure 6:Power module technology discussed by UMC
With the development of SiC modules, the respective routes around Tier1 and chip manufacturers can be explored, and there was no special attention before, and then it is necessary to take the time to collect this information for archiving and collation.
▲Figure 7. Package of power module
Each company's technical route and considerations are different. Taking ON Semiconductor as an example, its development focus will also be on the plastic die-casting module, and it can also be directly water-cooled. The difference between the die-casting module and the gel module, the module power density can be higher, the stray inductance can be lower, especially the silicon carbide can accept higher operating temperatures, to 200 °C or even more. The operating temperature of silicon carbide can be very high.
With the same system price, die-cast modules should be able to achieve greater potential and differentiation – ON Semiconductor is now in discussions with many automakers to make some specially manufactured main drive modules for them. The characteristics of the cooling plastic module, in addition to the relatively low stray inductance and high power density, are relatively good in terms of scalability. ON Semiconductor can make 150kW of power with three half-bridge modules, or it can combine the two of them to make 300kW, basically the space occupied is not much different. Compared with gel modules, the life cycle of die-casting modules is relatively long. In ON Semiconductor's two-sided cooling module, the IGBT is a smart chip with two mainly built-in sensors. One is a temperature sensor (accurate temperature detection), and the other is a current detection that is also built into it (the overall reaction time will be faster and better protect the system).
Figure 8: Onsenmei's technical route
Summary: In the competition of power semiconductors, the space for domestic substitution of domestic enterprises is very large, and from the perspective of future market demand, the requirements of supply chain security are placed in a very high position.