Patent ID: 8429964
Filing Date: 2013-04-30
Classification: B81B,G01F,Y10T

Abstract:
1. A thermal fluid flow sensor comprising: a heater resistive element provided in a structure forming a diaphragm and a temperature-measuring resistive element provided next to the heater resistive element, the thermal fluid flow sensor measuring an air flow rate, an upper insulating portion, which includes a first insulating film having tensile stress and a second insulating film having compressive stress stacked over an upper layer of the heater resistive element and the temperature-measuring resistive element, and a lower insulating portion, which includes a third insulating film having tensile stress, a fourth insulating film having compressive stress, and a fifth insulating film having tensile stress stacked in order, from bottom to top, under a lower layer of the heater resistive element and the temperature-measuring resistive element.