United Microelectronics Corporation (UMC)

United Microelectronics makes chips to other companies' designs. The filing describes it as one of the world's largest independent semiconductor foundries, using its own proprietary processes to fabricate integrated circuits to customer specifications rather than selling chips of its own. It was incorporated under R.O.C. Company Law as a company limited by shares in May 1980, its common shares have been listed on the Taiwan Stock Exchange since 1985 and the depositary shares on the NYSE since 19 September 2000. The principal executive office is in the Hsinchu Science Park in Taiwan, and the figures are stated in NT$.

What the wafers go into

Wafer sales are reported by application. Communication was 41.4% in 2025, consumer 30.6%, computer 11.6% and others 16.4%. The mix has shifted since 2023, when communication was 45.1% and consumer 24.0%. The company says it focuses on high growth, large volume applications including networking, telecommunications, internet, multimedia, PCs and graphics.

The process technologies

The company develops manufacturing process technologies designed for mass production, and says it was among the first in the foundry industry to enter commercial operation with line widths of 0.25, 0.18, 0.15 and 0.13 micron and 90, 65/55, 45/40, 28, 22 and 14 nanometer. The filing's reasoning is that as devices get smaller and consume less power, a foundry has to be able to shrink form factors aggressively, integrate multiple functions and cut power consumption, while carrying several process technologies at once for communication, consumer and computer products.

Design support

Beyond making the wafer, the company keeps a dedicated intellectual property and design support team so that a customer's specific design blocks work with the rest of the integrated circuit system as intended. The design service team works with customers and vendors early in the product cycle to line up the offerings needed, with the aim of shortening time to volume production. Customers get real-time online access to production data and specifications. Clean rooms, equipment and processes are selected and configured for flexibility, which the company says helps its cycle time, the period from customer order to wafer delivery.

Who buys

The primary customers by sales include integrated device manufacturers such as Texas Instruments and Intel, plus fabless design companies such as MediaTek, Realtek and Novatek. The top ten customers were 57.0% of operating revenues in 2025.

The plants and the two American deals

Fabs sit in the R.O.C., Singapore, the PRC and Japan, with land in the Hsinchu and Southern Taiwan Science Parks leased from the R.O.C. government and land at Pasir Ris leased from statutory boards of the Singapore government. United Semiconductor (Xiamen), established in 2014 for 12-inch foundry services, opened in November 2016, began mass production by the end of that year and ran 40nm and 28nm nodes from 2017; after transactions completed in July 2023, UMC and Hejian together hold 100% of it, and it is one of four 12-inch fabs. An expansion of the 300mm Fab 12A Phase 6 in the Southern Taiwan Science Park was announced in April 2021, and in February 2022 the board approved a new fab next to the existing 300mm Fab 12i in Singapore, whose first phase is designed for 30,000 wafers a month on 28nm and 22nm processes with production expected in the second half of 2026. In January 2024 UMC entered a collaboration with Intel to jointly develop and commercialise a 12nm process platform combining Intel's at-scale U.S. manufacturing capacity with UMC's mature-node foundry experience, with US-based 12nm production expected to begin in 2027, and in December 2025 it signed a memorandum of understanding with Polar Semiconductor to explore US-based 8-inch wafer production.

From UMC's annual report on Form 20-F for the year ended 31 December 2025. The filing