Rohm Semiconductor has split its first Indian outsourcing assignments between two OSAT partners: Tata Electronics will handle TOLL packaging and Suchi Semicon will handle TO-252, as the Japanese chipmaker extends a back-end outsourcing model it began in ASEAN countries and China several years ago.

"Tata is for TOLL, and Suchi is for TO-252 packaging," Makoto Terada, managing director of Rohm Semiconductor India, told EE Times. TOLL serves mainly the two-wheeler market, while Terada described the TO-252 customer base as "more like four-wheeler."

The company will start with legacy products, not new designs. "We are now requesting those OSAT partners to package existing products, legacy products first," Terada said. The first products will be power MOSFETs — consistent with Rohm's core analog and power focus, with no plans for advanced packaging in India at this stage.

Rohm reported a net loss of ¥158.4 billion (~$1 billion) for the fiscal year ended March 31, 2026, driven by an impairment related to its SiC business. Net sales rose 7.3% year over year to ¥481.1 billion (~$3 billion). The company employs 21,756 people across 97 locations.

What stays in-house?

Wafer fabrication will not move. "The wafer process will remain inside," Terada said, referring to the current India strategy. Production control also stays with Rohm. "Production control has to be done by ourselves, but the outsourcing ratio might be increased," he said.

The decision on which processes to outsource depends on region, location, and application, weighing capital efficiency, capacity, and supply chain requirements. "A mix of them," Terada said when asked which factor drives the decision.

The Indian partnerships remain in early-stage qualification. "Our quality sections are visiting them from time to time, and at the end of the process, the qualification has to be done," Terada said. Thermal management is also under evaluation. "Thermal management is a critical issue," he added.

Why Tata and Suchi?

Terada was blunt on partner selection: "They are ready," adding that the packages Tata is preparing match Rohm's portfolio requirements for India. Rohm chose two partners to move faster, though the division of labor may not be permanent. Asked whether both partners could eventually handle the same packages, Terada said, "That is possible," depending on demand.

The Suchi Semicon agreement also includes joint business development for locally manufactured semiconductors and joint marketing drawing on Suchi's local expertise. Terada acknowledged the broader field remains unsettled: "There are so many OSAT companies and partners, but at this moment, today, we do not know yet who will be the best."

Why is Rohm localizing in India?

Terada called supply chain resilience and the government's localization push "the biggest reason" for moving assembly and test into the country. A second reason: winning more designs from end customers. Government support, including the production-linked incentive (PLI) scheme and domestic value-addition requirements, also encourages customers to localize manufacturing.

Rohm also wants early visibility. "We wanted to be a kind of first adopter for the semiconductor industry in India," Terada said. He has proposed a talent development program to the Government of India under which engineers from OSATs or other companies could train at Rohm facilities for several months or years.

The local application mix shapes the product strategy. Two-wheelers are Rohm's primary target in India, unlike other regions that lean toward four-wheelers. The company has "many engagements with almost all OEMs and a few others [Tier 1s]," Terada said. AI data centers are another emerging opportunity, with Rohm promoting MOSFET and analog products to power equipment and unit suppliers rather than hyperscalers directly.

At electronica India, Rohm demonstrated local design work: an EFI reference design built around the UCHIP2 driver IC — designed and being validated in India, manufactured in Japan — targeting vehicles with engines up to 300 cc. Vishal Jain, LSI manager for analog LSI design at Rohm, said the design combines Rohm ICs, intelligent power devices, gate drivers, and high-voltage IGBTs and MOSFETs for engine control, fuel injection, and spark generation, plus protection functions and a watchdog timer. A 48V three-wheeler EV concept from Rohm's India design center paired 100-V automotive MOSFETs, including TOLL-package EcoMOS devices, with 5.5 kW continuous and 8.5 kW peak power.

How does this fit Rohm's wider manufacturing overhaul?

Rohm is expanding external manufacturing across its network. Key moves:

• Folding Japanese manufacturing subsidiaries into a wafer process company and an assembly company from April 1, 2026, with LAPIS and the Shiga facilities to follow in 2027, plus line relocation and site consolidation under the current midterm plan.
• Selling all of Rohm Electronics Dalian to Dalian Chengyue Precision Components Industry for about ¥4.2 billion (~$27 million) in May 2026, then outsourcing production at the site to cut fixed costs.
• HAIMOSIC, a Shanghai-based joint venture with Zhenghai Group, making SiC power modules.
• A 2023 capacity-sharing agreement with Toshiba for power devices, followed by a March 2026 MOU under which Mitsubishi Electric, Rohm, and Toshiba will discuss merging their power device and semiconductor businesses.

Rohm is taking a different route in GaN. The company plans to license TSMC's GaN process technology and transfer it to its Hamamatsu facility, targeting an end-to-end GaN production system by 2027 for AI servers and electric vehicles. That builds on the use of TSMC's 650V GaN process since 2023 and an automotive GaN partnership launched in 2024; once the transfer is complete, the automotive GaN partnership concludes while the companies continue collaborating on more compact, efficient power supply systems.

Can Indian capacity serve global demand?

Rohm has set no production volume target for its Indian OSAT partners. "I do not know how much we can support with local manufacturing," Terada said. He described India as an emerging but early-stage market for Rohm compared with other regions.

Still, TO-252 is a package Rohm already ships worldwide, and a successful Indian launch could scale beyond local demand. "If we manage launching in India, that is what I am expecting to expand to [global markets]," Terada said. "That is possible, but we start from the local demand."

Whether Tata and Suchi move from qualification to volume production for export will depend on the benchmark results Rohm is now gathering — and on how quickly India's localization incentives translate into design wins from the country's two-wheeler-dominated customer base.