On August 28, 2026, the Taoyuan District Prosecutors Office in Taiwan, China, initiated a search operation targeting Unimicron, a globally renowned manufacturer of integrated circuit (IC) substrates. The company stands accused of shipping printed circuit boards (PCBs) produced in mainland China to Taiwan, where they were relabeled as Taiwan-made products before being exported. This alleged maneuver was reportedly aimed at circumventing the high U.S. tariffs imposed on goods originating from mainland China.

During the operation, prosecutors raided Unimicron's headquarters and factory in Taoyuan, taking 14 senior executives and employees in for questioning. An additional four witnesses cooperated with the investigation. The following day, on August 29, the Taoyuan District Prosecutors Office confirmed that five company executives are facing charges, including forgery of private documents and falsely labeling the origin of products.

On the same day, Unimicron's stock price experienced a sharp fluctuation—initially surging before plummeting, ultimately closing down by 5.93%. In response, Unimicron issued a statement that evening acknowledging the investigation and pledging full cooperation. The company also emphasized that the incident is not expected to have a significant impact on its financial performance or operational stability.

Market analysts, however, caution that if the investigation substantiates claims of transit fraud, Unimicron could face several risks. These include customer-initiated supply chain audits, reevaluation of its export eligibility, and the potential loss of orders to competitors.