UMC raises 2026 capex to $2 billion with dual fab expansion

United Microelectronics Corp. is betting $2 billion that AI demand will cascade beyond bleeding-edge chips into the mature-node technologies the foundry has long specialized in.

United Microelectronics Corp.'s board approved a phased expansion across Singapore and Taiwan, committing $2 billion in 2026 capital expenditure to capture AI-driven demand for silicon photonics and specialty-node manufacturing — areas where the foundry competes directly with Taiwan Semiconductor Manufacturing Co. and GlobalFoundries.

"The rise of generative AI has fundamentally shifted the technology landscape, accelerating demand for technologies enabling higher performance, higher bandwidth, and greater system integration," Chairman Stan Hung said. The dual-track approach balances speed with capital discipline, he added.

In Singapore, UMC will expand cleanroom capacity for Phase 4 and purchase tools to boost silicon photonics output, leveraging an existing building shell to reduce lead times. In Taiwan, construction of a new fab shell at the Tainan campus will house future Phase 7 and Phase 8 facilities. The company reported second-quarter revenue of T$68.73 billion ($2.12 billion), up 17% from a year earlier, while net income surged 374.7% to T$42.26 billion.

The expansion shows that AI infrastructure demand is broadening beyond the most advanced nodes. While TSMC invests heavily in 2nm and 1nm technology to power the highest-performance AI accelerators, UMC's strategy targets the companion chips — silicon photonics for optical interconnects, power management ICs, and sensor hubs — that are equally essential to AI systems but manufactured on mature nodes. UMC shares have risen 120% year-to-date, far outpacing the broader market's 38.24% gain.

Why Mature Nodes Matter for AI

Generative AI's insatiable appetite for compute has focused attention on TSMC's 3nm and upcoming 2nm nodes, where Nvidia, Advanced Micro Devices, and Apple compete for capacity. But every AI server also requires dozens of specialty chips — interface bridges, voltage regulators, and optical transceivers — that are fabricated on 28nm, 22nm, and even more mature nodes. Silicon photonics, a key growth area for UMC's Singapore expansion, enables the high-bandwidth optical interconnects that link graphics processing units across data centers, a bottleneck that becomes more acute as cluster sizes grow.

CEO Jason Wang said the phased approach allows UMC to maintain capital discipline while deploying capacity flexibly. "The plan will be executed in phases, enabling UMC to remain focused on capital discipline while flexibly deploying capacity to fulfill customer demand," he said.

Geographic Diversification as a Strategic Hedge

The dual-site strategy serves two purposes. Tainan reinforces Taiwan's role as UMC's global hub for advanced research and packaging, while Singapore — already UMC's largest site outside Taiwan — provides geographic diversification for supply chain resilience. The approach mirrors a broader industry trend: TSMC is building fabs in Arizona, Japan, and Germany, while Intel Corp. has expanded in Ireland and Israel. UMC's Singapore Phase 4 expansion, with its pre-built shell, can come online faster than greenfield projects, reducing the typical three-to-four-year fab construction timeline.

UMC trades at a discount to TSMC on forward earnings, reflecting its focus on mature nodes that typically command lower margins. But the AI-driven demand for specialty chips could narrow that gap. If silicon photonics and specialty-node capacity become as constrained as advanced-node capacity has been, UMC's $2 billion bet may prove well-timed. The stock's 9.69% decline on the announcement day suggests the market is still weighing near-term dilution against the long-term opportunity.

This article is for informational purposes only and does not constitute investment advice.