Hillsboro, city (1990 pop. 37,520), seat of Washington co., NW Oreg., in the Tualatin valley; inc. 1876. Integrated circuits, other high-tech products, furniture, plastics, and medical equipment are manufactured in this growing city in Oregon's "Sunset Corridor." Meats and fruits and vegetables are processed and packed, there are wineries, and timber is also important. Settled c.1845, Hillsboro has a pioneer museum and cemetery and a notable old Scottish church.