Flow sensor

• US 6,705,160 B2
• Filed: 07/18/2002
• Issued: 03/16/2004
• Est. Priority Date: 07/19/2001
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Iwaki, Takao, Wado, Hiroyuki, Yamamoto, Toshimasa
• Primary Examiner(s): Lefkowitz, Edward
• Assistant Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US10/197,474
• Publication Number:
  US 20030015034A1
• Time in Patent Office: 607 Days
• Field of Search: 732/042.6, 732/041.7, 732/041.8, 732/042.3, 732/042.5, 732/041.9
• US Class Current: 73/204.26
• CPC Class Codes: G01F 1/692 Thin-film arrangements

Abstract

A thin-film type flow sensor having a thin-film part in which a plurality of patterned resistor films are sandwiched between a pair of insulator films. The resistance ratios among the resistor films are minimized from one sensor to another made from the same wafer. The flow sensor has a lower insulator film, the resistor films, and an upper film laminated in succession on a substrate. The resistor films include a patterned fluid thermometer, a temperature detector, and a heater. The heater has a wiring configuration in which resistor elements are connected in a parallel manner. The wiring widths of the heater and the thermometer can thus be made identical, so that the resistance ratios become invariant over the wafer surface, irrespective of a disparity in etching variations.

Claims

1. A flow sensor comprising:

a lower insulator film;

a plurality of resistor films, wherein the resistor films include a patterned heater and thermometer, and wherein at least a section of at least one of the resistor films has a wiring configuration in which resistor elements of a plurality of resistor elements are connected in a parallel manner; and

an upper insulator film, wherein the resistor films are laminated with and located between the upper insulator film and the lower insulator film.

2. The flow sensor of claim 1, wherein the section is at least a part of the heater.

3. The flow sensor of claim 2, wherein the thermometer has a substantially uniform wiring width, and the wiring width of the thermometer is the same as that of each of the resistor elements.

4. The flow sensor of claim 1, wherein the section is at least a part of the thermometer.

5. The flow sensor of claim 1, wherein the width of each of the resistor elements is substantially the same as that of the other resistor elements.

6. The flow sensor of claim 1, wherein the resistor films lie in the same plane and are spaced from one another in a predetermined order.

7. A flow sensor comprising:

a lower insulator film;

a plurality of resistor films, wherein the resistor films include;

a patterned heater; and

a patterned thermometer, wherein at least one of the thermometer and the heater has a wiring configuration in which a plurality of resistor elements are connected in a parallel manner, wherein the wiring width of the thermometer is the same as that of the heater; and

an upper insulator film, wherein the resistor films are laminated with and located between the upper insulator film and the lower insulator film.

8. A flow sensor comprising:

a lower insulator film;

a plurality of resistor films, wherein the resistor films include;

a patterned heater, which is defined by wiring strips; and

a patterned thermometer, which is defined by wiring strips, wherein at least one of the thermometer and the heater has a wiring configuration in which a plurality of resistor elements, which are defined by wiring strips, are connected in a parallel manner, wherein the width of each of the strips defining the thermometer is the same as that of the strips defining the heater; and

an upper insulator film, wherein the resistor films are laminated with and located between the upper insulator film and the lower insulator film.