Flow detector element of thermosensible flow sensor

• US 20070295083A1
• Filed: 11/29/2006
• Published: 12/27/2007
• Est. Priority Date: 05/15/2006
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Kawai, Masahiro
• Granted Patent: US 7,426,857 B2
• Time in Patent Office: Days
• US Class Current: 73/204.26
• CPC Class Codes: G01F 1/6845 Micromachined devices
• CPC Class Codes: G01F 1/688 using a particular type of heating, cooling or sensing element G01F1/6847 takes precedence
• CPC Class Codes: G01F 1/69 of resistive type

Abstract

Detection accuracy of flow rates is higher even when the temperature of fluid is varied or when there is any difference between temperature of fluid and that around a thermosensible flow sensor. A thermosensible detector element comprises an insulating support film formed on the surface of a plate-like substrate, a heat resistor and a fluid temperature-measuring resistor made of thermosensible resistive films formed on this support film, an insulating protective film formed on this thermosensible resistive film, and cavities and formed under respective thermosensible resistive films by removing partially the plate-like substrate, and in which flow velocity of fluid is measured on heat transfer phenomenon from the portion heated by the heat resistor to fluid, and top surface of the cavity located under the fluid temperature-measuring resistor is formed within the part where the fluid temperature-measuring resistor is located.

Claims

1. A flow detector element in which a support film is formed on the surface of a substrate, as well as a heat resistor and a fluid temperature-measuring resistor that are made of a thermosensible resistive film are formed on said support film, and there are provided under said heat resistor and said fluid temperature-measuring resistor cavities formed by removing a part of said substrate;

wherein the top surface of said cavity located under said fluid temperature-measuring resistor is formed within a portion where said fluid temperature-measuring resistor is located.