Denso Drops Rohm Bid: What Happens to Japan's Power Semiconductor Alliance

Semiconductor analyst Satoshi Oyama breaks down why Denso is withdrawing from Rohm and whether the Rohm-Toshiba-Mitsubishi Electric three-way alliance can survive.

• Denso is withdrawing its Rohm acquisition proposal after Rohm signaled reluctance; Oyama says he is relieved — a captive auto-group semiconductor supplier would harm the industry.
• Rohm faces a June shareholder meeting with pressure to show value after rejecting Denso; the most likely move is accelerating its announced but stalled Toshiba Device integration.
• Toshiba Device employees are reportedly reluctant to merge with Rohm, but Oyama expects the deal to proceed anyway because Rohm has now publicly committed to it.
• Mitsubishi Electric’s IGBT and Toshiba’s silicon MOSFET share roughly 70% of front-end process steps — real manufacturing scale exists if combined, but Oyama doubts Mitsubishi will join.
• Rohm’s SiC and Mitsubishi’s IGBT serve overlapping end markets and could be sold together as alternatives, mirroring Infineon’s dual-technology customer strategy.
• About 80% of SiC demand is EV-driven; the EV slowdown is real but Oyama views it as a timing issue, not a structural collapse — rising oil prices since March may accelerate a rebound.
• Japan’s biggest risk is internal turf wars over who controls a merged entity rather than focusing on Infineon and rising Chinese power semiconductor players.

2026-04-27 · Watch on YouTube