title: Hot controllers
abstract: Over the last few years, the semiconductor industry has put much emphasis on ways to improve the accuracy of thermal mass flow controllers (TMFCs). Although issues involving TMFC mounting orientation and pressure effects have received much attention, little has been done to address the effect of changes in ambient temperature or process gas temperature. Scientists and engineers at Qualiflow have succeeded to solve the problem using a temperature correction algorithm for digital TMFCs. Using an in situ environmental temperature compensation technique, we calculated correction factors for the temperature effect and obtained satisfactory results with both the traditional sensor and the new, improved thin-film sensors
keyphrases: thermal mass flow controller temperature correction algorithm in situ environmental temperature compensation semiconductor manufacturing process gas flow