Semiconductor production typically involves wafer fabrication in one country, die packaging in another, and final testing in a third. CBP's substantial transformation standard means the country where the most significant processing occurs — usually wafer fabrication — is the country of origin, regardless of where the device is packaged or shipped from. This distinction is critical when assessing Section 301 exposure.

Importers should retain technical datasheets, manufacturer part numbers, functional specifications, and bills of materials. For components subject to antidumping or Section 301 orders, country-of-origin certifications from the manufacturer and, where applicable, scope ruling requests from CBP provide the strongest compliance foundation.