On July 7, MEMS foundry Silex Microsystems announced that it has signed a definitive acquisition agreement with Onsemi to purchase a 200mm integrated circuit manufacturing facility in Mountain Top, Pennsylvania, United States, for purchase consideration of $40 million. The transaction is expected to close between the end of 2027 and the beginning of 2028, subject to customary regulatory approvals including review by the FIUS.

The acquisition is structured as an asset transaction, covering production facilities, real property, infrastructure, and manufacturing equipment, but does not involve the acquisition of a legal entity. Silex has paid a deposit of $10 million upon signing, with the remaining $30 million due at closing.

Strategic Rationale

This move marks Silex's formal entry into U.S.-based manufacturing and represents a pivotal step in its long-term growth strategy. The majority of the company's core customers are located in the United States, and establishing domestic production capacity will significantly shorten delivery lead times, deepen customer collaboration, and effectively mitigate geopolitical risk. Furthermore, acquiring an existing wafer fab—by leveraging existing infrastructure, equipment, personnel, and customer relationships—substantially reduces execution risk and accelerates production ramp-up.

For Onsemi, the sale of this facility is part of its "Fab Right" strategy, aimed at optimizing its manufacturing footprint, reducing costs, and focusing on its most competitive production lines. Onsemi expects to save approximately $35 million in annual operating costs through this transaction and the concurrent sale of its Tarlac facility in the Philippines to Greatek.

Facility Scale and Retrofit Plan

The facility currently features approximately 3,000 square meters of cleanroom space, with an additional 12,000 square meters available for expansion—roughly double the cleanroom footprint of Silex's existing facility in Järfälla, Sweden, providing ample room for future MEMS capacity growth.

Silex plans to fully convert the facility into a MEMS wafer fab ("Silex US Fab"). Between 2026 and 2027, Silex will progressively advance product qualification, knowledge transfer, and operational system integration, including training U.S.-based engineers, importing process expertise, and adapting Silex's systems and workflows. Following closing, Silex intends to offer continued employment to approximately 130 existing staff members at the facility.

Conclusion

This acquisition continues Silex's strategic path of expanding capacity through M&A—previously, in 2021, the company acquired Elmos's 200mm wafer fab in Dortmund, Germany, for €85 million. As the world's largest pure-play MEMS foundry, Silex is now strengthening its leadership position in high-growth MEMS application areas such as medical devices, cloud infrastructure, and autonomous driving through a dual-base "Europe + United States" manufacturing layout.

CONEVO IC Parts Supplier

Conevo Electronics is a leading global IC distributor specializing in FPGA, MCU, DSP, Amplifiers, and Memory devices. With a worldwide supply chain network, Conevo provides competitive pricing, immediate shipment, and professional technical support to ensure reliable component sourcing for project success. Featured Onsemi IC Hot Picks

All IC devices are available through CONEVO Elec with verified stock, full traceability, and technical support.

Website: www.conevoelec.com

Email: info@conevoelec.com