Bosch to acquire US chipmaker TSI Semiconductors, invest $1.5B in Roseville site

Bosch is expanding its semiconductor business with silicon carbide chips. The technology company plans to acquire assets of the US chipmaker TSI Semiconductors, based in Roseville, California. With a workforce of 250, the company is a foundry for application-specific integrated circuits, or ASICs. Currently, it mainly develops and produces large volumes of chips on 200-millimeter silicon wafers for applications in the mobility, telecommunications, energy, and life sciences industries.

Bosch intends to invest more than US$1.5 billion in the Roseville site and convert the TSI Semiconductors manufacturing facilities to state-of-the-art processes. Starting in 2026, the first chips will be produced on 200-millimeter wafers based on silicon carbide (SiC).

In this way, Bosch is systematically reinforcing its semiconductor business, and will have significantly extended its global portfolio of SiC chips by the end of 2030.

Above all, the global ramp-up of electromobility is resulting in huge demand for such special semiconductors. Bosch said that the full scope of the planned investment will be heavily dependent on federal funding opportunities available via the CHIPS and Science Act as well as economic development opportunities within the State of California. Bosch and TSI Semiconductors have reached an agreement to not to disclose any financial details of the transaction, which is subject to regulatory approval.

With the acquisition of TSI Semiconductors, we are establishing manufacturing capacity for SiC chips in an important sales market while also increasing our semiconductor manufacturing, globally. The existing clean-room facilities and expert personnel in Roseville will allow us to manufacture SiC chips for electromobility on an even larger scale.

—Dr Stefan Hartung, the chairman of the Bosch board of management

The new location in Roseville will reinforce Bosch’s international semiconductor manufacturing network. Starting in 2026, following a retooling phase, first SiC chips will be produced on 200-millimeter wafers in a facility offering roughly 10,000 square meters of clean-room space.

At an early stage, Bosch invested in the development and production of SiC chips. Since 2021, it has been using its own proprietary, highly complex processes to mass-produce them at its Reutlingen location near Stuttgart. In the future, Reutlingen will also produce them on 200-millimeters wafers.

By the end of 2025, the company will have extended its clean-room space in Reutlingen from roughly 35,000 to more than 44,000 square meters.

SiC chips are a key component for electrified mobility. By extending our semiconductor operations internationally, we are strengthening our local presence in an important electric vehicle market.

—Dr Markus Heyn, member of the Bosch board of management and chairman of the Mobility Solutions business sector

Power semiconductors from Bosch

Demand for chips for the automotive industry remains high. By 2025, Bosch expects to have an average of 25 of its chips integrated in every new vehicle. The market for SiC chips is also continuing to grow quickly—by 30% a year on average. The main drivers of this growth are the global boom and ramp-up of electromobility.

In electric vehicles, SiC chips enable greater range and more efficient recharging, as they use up to 50% less energy. Installed in these vehicles’ power electronics, they ensure that a vehicle can drive a significantly longer distance on one battery charge; on average, the possible range is 6% greater than with silicon-based chips.

In its wafer fabs in Reutlingen and Dresden, Bosch has invested more than €2.5 billion in total since 200-millimeter technology was introduced in 2010. On top of this, billions of euros have been invested in developing microelectronics. Independently of the investment now planned in the United States, the company announced in summer last year that it will be investing a further €3 billion in its semiconductor business in Europe, both as part of its investment planning and with the aid of the EU’s “Important Project of Common European Interest on Microelectronics and Communication Technologies” program.