EP0134859A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Fluid flow sensors
Assignee: Honeywell Inc
•
Filing: 1983-09-21
•
Granted: —
•
Expires: 2003-09-21
Abstract
Abstract The sensor device includes a heater (26) and two heat sensors (22, 24) disposed on opposite sides of the heater, the heater and sensors being defined by thin film members (32, 34) suspended above a depression (30) in a semiconductor base (20). the air flow to be sensed passing over both sides of the thin film members.
Inventors
- 👤 Robert G. Johnson
- 👤 Robert E. Higashi
- 👤 Philip J. Bohrer
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 05:53
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/696; G01F1/698; G01F1/684; G01F1/6845; G01F1/699
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
43 words
A fluid flow sensor device comprising a heater and two heat sensors disposed on opposite sides of the heater, characterised in that the heater (26) and heat sensors (22, 24) are suspended in the fluid flow and are defined by thin film members.
Claim 2
Dependent Claim
43 words
A fluid flow sensor device comprising a heater and two heat sensors disposed on opposite sides of the heater, characterised in that the heater (26) and heat sensors (22, 24) are suspended in the fluid flow and are defined by thin film members.
Claim 3
Dependent Claim
55 words
The device of Claim 1, characterised in that the heater and sensor each comprise a resistive element composed of a serpentine pattern of resistive material in lines, adjacent lines being separated by a line width and the sensors being separated from the heater by a distance in the range of one to five line widths.
Claim 4
Dependent Claim
17 words
The device of Claim 2, wherein the width of a line is five micrometer ( V m),
Claim 5
Dependent Claim
78 words
The device of Claim 1, 2 or 3, characterised in that the heater and sensors are mounted on but separated from a semiconductor base (20), the base comprising (100) silicon having a (100) plane and (110) direction, the heater and sensors lying in a plane substantially parallel to the (100) plane, and means (32, 34) connecting the heater and sensors to the base having a configuration oriented at a non-zero angle (112) to the (110) direction, preferably 45°.
Claim 6
Independent Claim
26 words
The device of any one of the preceding claims, characterised by means (116) operating the heater in a pulsed fashion, preferably with equal spacing and duration.
Claim 7
Independent Claim
28 words
The device of any one of the preceding claims, characterised by means (Figure 4) operating the heater at a substantially constant temperature under both flow and no-flow conditions.
Claim 8
Dependent Claim
32 words
7, The device of any one of the preceding claims, characterised in that the heater and sensors (which may be of permalloy) are encapsulated in a dielectric material, such as silicon nitride.
Claim 9
Dependent Claim
50 words
The device of Claim 4 or Claim 5, 6 or 7 as appendant to Claim 4 characterised in that the base (20) is provided with a depression (30A), the heater and sensors being suspended over the depression which is open at its upstream side to receive a flow of fluid.
Claim 10
Dependent Claim
42 words
The device of Claim 2, or any one of Claims 3 to 8 as appendant to Claim 2, characterised in that the heater and sensors comprise a single resistive element (26F, 26G), the element having two voltage taps (98, 100; 98G, 102G).
Claim 11
Independent Claim
28 words
The device of any one of the preceding claims, wherein at least one of the thin film members includes reinforcing means (90,96,106...) preferably a thin film of permalloy.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.