ROHM's New IGBTs: The Quiet Powerhouse Driving EV and Industrial Efficiency

KYOTO, Japan – August 26, 2026 – In the relentless march of electrification, the spotlight often falls on high-profile technologies like long-range batteries and powerful main drive motors. Yet, the foundation of this revolution is built on a bedrock of less glamorous, but utterly critical, components. Today, Japanese semiconductor manufacturer ROHM Co., Ltd. has reinforced that foundation with the launch of its 4th-generation 650V Insulated Gate Bipolar Transistors (IGBTs), a move that underscores the enduring importance of silicon in a world increasingly captivated by novel materials.

The new components, designed for automotive auxiliary systems and industrial equipment, promise a combination of efficiency and robustness that speaks directly to the core challenges of modern power electronics. While not as headline-grabbing as their Silicon Carbide (SiC) cousins, these IGBTs are the workhorses that will power the electric compressors, heaters, and industrial inverters quietly enabling a more efficient future.

An Efficiency Engine Under the Hood

At its core, ROHM's announcement is a story of incremental, yet profound, engineering achievement. The company claims its new IGBTs achieve "class-leading" low conduction loss, specified by a collector-emitter saturation voltage (VCE(sat)) of just 1.55V. In the world of power semiconductors, this metric is a direct measure of efficiency—a lower number means less energy is wasted as heat when the switch is on.

A look across the competitive landscape shows this claim holds water. ROHM's figure puts it on par with top-tier offerings from giants like STMicroelectronics, whose own 650V series also touts a 1.55V VCE(sat), and places it squarely in the elite tier alongside Infineon and ON Semiconductor, whose best-in-class products hover around the same mark. This isn't a revolutionary leap, but a hard-won advance in a mature technology, achieved through a complete redesign of the device's internal structure. For design engineers, this translates into tangible benefits: smaller heat sinks, more compact systems, and ultimately, greater overall efficiency. In an electric vehicle, more efficient auxiliary systems, like air conditioning compressors or cabin heaters, mean less drain on the main battery and more range for the driver.

However, efficiency in power electronics often comes at the cost of durability. This is where ROHM's second key specification comes into play: a short-circuit withstand time of 7 microseconds (µs). This figure represents the device's ability to survive a catastrophic overcurrent event long enough for protective circuits to intervene. Compared to some competitors whose ratings are as low as 3µs, this extended tolerance provides a crucial safety margin. In demanding applications like an industrial motor inverter or an EV’s high-voltage heater, this robustness isn't a luxury; it's a prerequisite for safety and long-term reliability. By marrying low-loss performance with high short-circuit tolerance—a notoriously difficult trade-off—ROHM is addressing a primary pain point for system designers.

A Strategic Play in a Shifting Market

The launch of a new silicon IGBT might seem counterintuitive in an era dominated by talk of wide-bandgap semiconductors like SiC and Gallium Nitride (GaN). SiC has rightly earned its place in high-power, high-frequency applications, most notably the main traction inverters of electric vehicles, where its superior performance can justify its higher cost. However, ROHM's focus on 650V IGBTs reveals a shrewder, more nuanced market strategy.

The global market for IGBTs remains massive, projected to grow from nearly $8 billion in 2025 to well over $10 billion by the end of the decade. While SiC is the fastest-growing segment, IGBTs still command the lion's share of the automotive power module market. This is because for a vast array of applications—from the aforementioned EV auxiliary systems to countless industrial motors, pumps, and power supplies—the extreme performance of SiC is overkill, and its cost remains a significant barrier.

ROHM is strategically targeting this lucrative and persistent segment. By delivering a highly optimized silicon solution that is compliant with the rigorous AEC-Q101 automotive reliability standard, the company is doubling down on a market that values proven reliability and cost-effectiveness. It's a pragmatic recognition that the transition to full electrification is not a monolithic shift but a complex mosaic of different technologies serving different needs. These new IGBTs are not competing with SiC for the main-drive throne; they are securing the essential infrastructure that supports the entire kingdom.

Navigating a Landscape of Giants and Alliances

ROHM's product launch does not happen in a vacuum. It is a calculated move within a fiercely competitive global power semiconductor industry undergoing significant realignment. The market is currently dominated by European giant Infineon, and the pressure to achieve scale is immense. This context makes ROHM's recent activities particularly noteworthy.

Earlier this year, reports surfaced of a landmark memorandum of understanding between ROHM, Toshiba, and Mitsubishi Electric to explore integrating their power semiconductor businesses. Such an alliance would create a Japanese powerhouse capable of competing more effectively on the world stage, pooling R&D resources and manufacturing capacity to challenge established leaders. This new IGBT lineup can be seen as a demonstration of the individual technological prowess ROHM brings to that potential partnership.

Complicating this picture is the recent, unsolicited 1.3 trillion yen acquisition bid for ROHM from automotive parts titan Denso. This move highlights the profound strategic importance that major Tier 1 suppliers now place on securing their own semiconductor supply chains. Denso, a key part of the Toyota ecosystem, clearly sees in-house power chip expertise as critical to its future. ROHM's leadership is now at a crossroads, weighing a future as an anchor of a new Japanese national champion against one as the integrated core of an automotive conglomerate.

Regardless of the path taken, the introduction of these 4th-generation IGBTs confirms that ROHM possesses the engineering depth to remain a vital player. The new product series, available in multiple packages including discrete components and bare wafers, shows a commitment to serving a wide range of customer needs and signals the company's intent to continue innovating on this essential technology for years to come.