UMC starts mass production of silicon photonics wafers at Singapore fab; shares fall

According to CNBC, United Microelectronics Corporation (UMC) said it has begun mass production of silicon photonics wafers at its Singapore facility, marking the company’s first such output. UMC said it worked with SILITH Technology to move the silicon photonics platform from development to production readiness in 18 months, and plans to make its own 12-inch silicon photonics platform available for customer product development by 2027. Citi analysts said they see an improving outlook in the second half of the year, forecasting a 13% quarter-on-quarter sales increase in the second quarter of 2026 and a recovery in gross margin. UMC reported June sales rose 22.85% year-on-year to NT$23.12 billion ($719.21 million), with first-half cumulative sales up 11.28%; the stock fell nearly 5% in Taiwan on Tuesday before trimming losses to trade 1.6% lower.