Denso's $8.3B Rohm Bid Signals Crisis in Japan's Power Chip Industry

Denso's $8.3B Bid Follows 50B Yen Loss

In March 2026, Japanese auto-parts giant DENSO launched a 1.3 trillion yen ($8.3 billion) takeover bid for chipmaker ROHM, a move that sent shockwaves through an already fragile industry. The offer, one of the largest in Japan's semiconductor history, is a direct response to the sector's deepening crisis. Investors reacted with skepticism, sending DENSO's shares down 5.6% as they questioned the wisdom of acquiring a struggling firm. ROHM, once a pillar of Japan's chip dominance, is projected to suffer a 50 billion yen net loss for the fiscal year ending March 2025, its first annual loss in 12 years. The red ink is driven by a 30 billion yen equipment impairment charge after its factory utilization rate plunged below 30%.

ROHM's troubles are not isolated. Renesas Electronics saw its H1 2025 net loss balloon to a record 175.3 billion yen after it lost a $2 billion prepayment to SiC supplier Wolfspeed, which filed for bankruptcy protection. Meanwhile, Mitsubishi Electric has indefinitely postponed the expansion of its SiC wafer factory in Kumamoto. This wave of financial distress and canceled investments reveals a systemic breakdown, forcing companies like DENSO to take radical steps to secure critical components for electric vehicles (EVs).

China Seizes 33% of SiC Market with 60% Cost Advantage

Japan's power semiconductor industry is buckling under a two-front assault from China: a rapidly vanishing end-market and aggressive supply chain competition. While Japanese automakers were slow to electrify—with Japan's EV penetration still below 10%—China's has soared past 60%, creating a massive domestic market for its own chipmakers. This divergence has left Japanese suppliers like ROHM, heavily tied to Toyota and Honda, with oversized investments and weak demand.

More critically, Chinese companies have systematically dismantled Japan's leadership in the supply chain. In silicon carbide (SiC), a key material for high-efficiency EVs, Chinese firms Tianke Heda and SICC now control a combined global market share of over 33%. They achieved this by leveraging a stark cost advantage; a 6-inch Chinese SiC substrate costs around $120, roughly 60% less than the $270 price for a comparable Japanese product. This has rendered Japanese firms that rely on imported substrates uncompetitive. China's share of the downstream SiC device market has already doubled from 7.1% in 2022 to 13.4% in 2024, and the technology gap with Japanese leaders has shrunk to under three years.

Fragmentation Forces Consolidation as Tech Gaps Narrow

The external pressure from China has exposed a fatal internal weakness: extreme fragmentation. Japan's power semiconductor market is split among five major players—Mitsubishi Electric, Fuji Electric, Toshiba, ROHM, and Renesas—none of which holds more than 5% of the global market. Years of rivalry have thwarted collaboration. A proposed alliance between ROHM and Toshiba to jointly produce chips stalled over issues of trust and control, echoing the failure of a potential Honda-Nissan merger. This inability to unite has left them vulnerable.

Consolidation is no longer a choice but a necessity for survival. DENSO's acquisition of ROHM aims to create a vertically integrated powerhouse capable of competing on a global scale. However, time is running out. While Japan maintains a slim 1-2 year lead in traditional silicon-based chips, that narrows to about three years for SiC, and in the emerging Gallium Nitride (GaN) space, Japan is already 2-3 years behind Chinese competitors like Innoscience. The industry's final hope may lie in next-generation materials like Gallium Oxide and Diamond, where Japan holds an early research lead. Yet, even here, Chinese firms are closing in, threatening to repeat the playbook that conquered the SiC market.