Unimicron Shares Slide as Prosecutors Search Company

Unimicron Technology is a major supplier of ABF substrates used in high-performance computing and AI server chip packaging. The company has benefited from rising demand for artificial-intelligence infrastructure and advanced packaging, helping its shares reach a record high. The investigation is significant because allegations involving trade practices, financial reporting or insider trading could affect investor confidence in a key link of the semiconductor supply chain.

The Taoyuan District Prosecutors Office recently searched Unimicron and questioned personnel, according to local reports. Market speculation has linked the inquiry to alleged origin laundering to evade tariffs, false accounting and insider trading, though prosecutors have not publicly established wrongdoing or responsibility. Unimicron shares fell more than 6% intraday after the news emerged, retreating from their record. The company said it would fully cooperate with investigators and that operations remained normal.