Hsinchu Holland International School has been here for over 25yrs. Kindergarten – Grade 12 students. AFAIK, they are the only fully licensed international school in Hsinchu - though that may have changed recently.
Another option which has been popular with some of our colleagues here is the National Experimental High School but it’s ROC curriculum and they only admit children of employees of private enterprises in the Science Park, government organizations, Industrial Technology Research Institute, National Chiao Tung University and National Tsing Hua University.