Under the Hood: How is SiC Reshaping the Automotive Supply Chain?

The global automotive industry is pouring billions of dollars into SiC semiconductors, hoping that they could be key to transforming vehicle power systems. This shift is rapidly changing the supply chain at all levels, from components to modules.

In the previous piece “SiC vs. Silicon Debate: Will the Winner Take All?,” we explored SiC’s unique physical properties. Its ability to facilitate high-frequency fast charging, increase range, and reduce vehicle weight has made it increasingly popular in the market of electric vehicles (EVs).

Research from TrendForce shows that the main inverter has become the first area for a substantial penetration of SiC modules. In 2022, nearly 90% of all SiC usage in conventional vehicles was in main inverters. As demand grows for longer range and quicker charging times, we’re seeing a shift in vehicle voltage platforms from 400V to 800V. This evolution makes SiC a strategic focus for automotive OEMs, likely making it a standard component in main inverters in the future.

However, it is common for now that SiC power component suppliers fail to meet capacity and yield expectations – a challenge that directly affects car production schedules. This has led to a struggle for SiC capacity that is impacting the entire market segment.

Device Level: Burgeoning Strategic Alliances

Given the long-term scarcity of SiC components, leading OEMs and Tier 1 companies are vying to forge strategic partnerships or joint ventures with key SiC semiconductor suppliers, aiming to secure a steady supply of SiC.

In terms of technology, Planar SiC MOSFETs currently offer more mature reliability guarantees. However, the future appears to lie in Trench technology due to its cost and performance advantages.

Infineon and ROHM are leaders in this technology, while Planar manufacturers like STM, Wolfspeed, and On Semi are gradually transitioning to this new structure in their next-generation products. The pace at which customers embrace this new technology is a trend to watch closely.

Module Level: Highly-customized Solutions

When it comes to key main inverter component modules, more automakers prefer to define their own SiC modules – they prefer semiconductor suppliers to provide only the bare die, allowing chips from various suppliers to be compatible with their custom packaging modules for supply stability.

For instance, Tesla’s TPAK SiC MOSFET module as a model case for achieving high design flexibility. The module employs multi-tube parallelism, allowing different numbers of TPAKs to be paralleled in the same package based on the power level in the EV drive system. The bare dies for each TPAK can be purchased from different suppliers and allow cross-material platform use (Si IGBT, SiC MOSFET, GaN HEMT), establishing a diversified supply ecosystem.

China’s Deep Dive into SiC Module Design

In the vibrant Chinese market, automakers are accelerating the investment in SiC power modules, and are collaborating with domestic packaging factories and international IDMs to build technical barriers.

• Li Auto has collaborated with San’an Semiconductor to jointly establish a SiC power module packaging production line, expected to go into production in 2024. 
• NIO is developing its own motor inverters and has signed a long-term supply agreement with SiC device suppliers like ON Semi.
• Great Wall Motor, amidst its transformation, has also focused on SiC technology as a key strategy. Not only have they set up their own packaging production line, but they’ve also tied up with SiC substrate manufacturers by investing in Tongguang Semiconductor.

Clearly, the rising demand for SiC is redrawing the map of the value chain. We anticipate an increase in automakers and Tier 1 companies creating their unique SiC power modules tailored for 800-900V high-voltage platforms. This push will likely catalyze an influx of innovative product solutions by 2025, thereby unlocking significant market potential and ushering in a comprehensive era of EVs.