GB2108133A - Electrical gas discharge polymerization method of coating a resistor - Google Patents

Electrical gas discharge polymerization method of coating a resistor Download PDF

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Publication number
GB2108133A
GB2108133A GB08215541A GB8215541A GB2108133A GB 2108133 A GB2108133 A GB 2108133A GB 08215541 A GB08215541 A GB 08215541A GB 8215541 A GB8215541 A GB 8215541A GB 2108133 A GB2108133 A GB 2108133A
Authority
GB
United Kingdom
Prior art keywords
resistor
corrosion
polymerization
gas discharge
protective layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB08215541A
Other versions
GB2108133B (en
Inventor
Dr Werner Grunwald
Kurt Burger
Heinz Friedrich
Dr Heiko Gruner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of GB2108133A publication Critical patent/GB2108133A/en
Application granted granted Critical
Publication of GB2108133B publication Critical patent/GB2108133B/en
Expired legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/62—Plasma-deposition of organic layers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F2/00—Processes of polymerisation
    • C08F2/46—Polymerisation initiated by wave energy or particle radiation
    • C08F2/52—Polymerisation initiated by wave energy or particle radiation by electric discharge, e.g. voltolisation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/18—Circuit arrangements for generating control signals by measuring intake air flow
    • F02D41/187—Circuit arrangements for generating control signals by measuring intake air flow using a hot wire flow sensor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
    • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
    • G01F1/688—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element
    • G01F1/69—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow using a particular type of heating, cooling or sensing element of resistive type
    • G01F1/692—Thin-film arrangements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/10—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/10—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables
    • G01P5/12—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables using variation of resistance of a heated conductor

Abstract

A method of providing a corrosion-resistant hydrophobic protective layer (18) of dielectric material on a temperature-dependent resistor (3) comprises subjecting the resistor to a monomeric organic substance (e.g. hexamethyl disiloxane or hexafluoropropylene) which is polymerized on the surface of the resistor from the vapour phase with the assistance of energy from an electrical gas discharge. The polymerization is interrupted at least once so as to promote nucleus formation (seed formations) and provide a pinhole-free layer. <IMAGE>

Description

1 GB 2 108 133 A 1
SPECIFICATION Method of coating a resistor
The present invention relates to a method of providing a protective layer on temperature dependent resistor.
A measuring probe is known in which a temperature-dependent resistor formed as a layer is in direct contact with a flowing medium. The resistance layer is subject to corrosive attack from the medium and measurement errors are caused by any electrical conductivity of the medium and/or change in the heat transfer resistance.
According to the present invention there is provided a method of providing a corrosion resistant hydrophobic protective layer of di electrical material on a temperature-dependent resistor, comprising the steps of subjecting the temperature-dependent resistor to a monomeric organic substance which is polymerized on the surface of the resistor from the vapour phase with the assistance of energy from an electrical gas discharge, and interrupting the polymerisatio n at least once.
The polymerization may be effected by a non self-maintaining as discharge which is sustained 90 by thermionic emission electrons, or by a self sustaining glow discharge.
A thin, such as about 0. 1 to 2 /tm thick, closed layer possessing extremely small heat transfer resistance can be produced, which inhibits deposits by hydrophoby and thereby provides long-term stability of the resistor.
By interrupting, at least once, the polymerization process, nucleus formation (seed formation) during the condensation is repeatedly promoted, so that a pinhole-free layer is formed.
An example of the present invention will now be more particularly described with reference to the accompanying drawing, the single figure of which is a schematic view of a temperature dependent resistor coated by a method exemplifying the invention and arranged as a measuring probe in an engine induction duct.
Referring now to the drawing, there is shown an induction duct 1 of an internal combustion engine, through which air inducted by the engine 110 can flow. Arranged in the duct 1 is a temperature dependent resistor 3 serving as a measuring probe for the flow rate of the inducted air. The resistor 3 may be formed as a resistance layer or coating applied by a known process to one or both sides of support 17. If the support 17 is made from an electrically conductive material, then an insulating layer (not shown) is provided between the resistance layer and the support 17.
A dielectric, corrosion-resistant, pinhole-free, hydrophobic protective layer 18 is applied to the resfstance layer. The protective layer 18 should, if possible, be no thicker than 4 ym, preferably 0.5 am, so that the heat transfer between the flowing air and the resistance layer is impeded as little as possible and the measuring probe can respond rapidly to temperature changes. The protective layer is an organic substance, preferably a silicon- organic substance, which is precipitated from the vapour phase by radiation polymerization. Hexamethyl disiloxane or hexafluoro-propylene may be used as the starting monomer for such polymerization. Starting materials of such a type for the production of a protective layer by polymerization are disclosed in, for example, DEOS 2 263 480, DE-AS 2 537 416 and DE-OS 2 625 448. Also disclosed in these specifications are methods of precipitating a layer by polymerization from the vapour phase by means of energy from an electric gas discharge. Thus the polymerization can be effected by a non selfmaintaining gas discharge sustained by thermionic emission electrons, or by a self- sustaining glow discharge. The polymerization operation is interrupted at least once, causing nucleus formation to be promoted afresh during condensation and a pinhole-free layer to be formed by multiple condensation.
A resistance layer provided with a protective layer by a method examplifying the invention may, when used for air flow rate measurement, be protected from corrosive attack by the flowing air and may avoid measurement errors arising from any electrical conductivity of the air or from a change in the heat transfer resistance due to deposits.

Claims (6)

Claims
1. A method of providing a corrosion-resistant hydrophobic protective layer of dielectric material on a temperature- dependent resistor, comprising the steps of subjecting the temperaturedependent resistor to a monomeric organic substance which is polymerized on the surface of the resistor from the vapour phase with the assistance of energy from an electrical gas discharge, and interrupting the polymerization at least once.
2. A method as claimed in claim 1, wherein the polymerization is effected by a non selfmaintaining gas discharge which is sustained by thermlonic emission electrons.
3. A method as claimed in claim 1, wherein the polymerization is effected by a self-sustaining glow discharge.
4. A method as claimed in any one of the preceding claims, wherein the substance is a silicon-organic substance.
5. A method of providing a corrosion-resistant hydrophobic protective layer of dielectric material on a temperature- dependent resistor, substantially as hereinbefore described with reference to the accompanying drawing.
6. A temperature-dependent resistor provided with a corrosion-resistant hydrophobic protective layer of dielectric material by a method as claimed in any one of the preceding claims.
New claims or amendments to claims filed on 16 December 1982 Superseded claims 1 New or amended claims:- 1. A method of providing a corrosion-resistant 2 GB 2 108 133 A 2 hydrophobic protective layer of dielectric material on a temperature- dependent resistor, comprising the steps of subjecting the temperaturedependent resistor to a monomeric organic substance, which is polymerized on the surface of the resistor from the vapour phase with the assistance of energy from an electrical gas discharge and which is such as to provide a corrosion resistant hydrophobic dielectric polymer, and interrupting the polymerization at least once.
Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1983. Published by the Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained 1 a,% r t 11,
GB08215541A 1979-01-04 1982-05-27 Electrical gas discharge polymerization method of coating a resistor Expired GB2108133B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19792900200 DE2900200A1 (en) 1979-01-04 1979-01-04 MEASURING PROBE WITH PROTECTIVE LAYER AND METHOD FOR PRODUCING A PROTECTIVE LAYER ON A MEASURING PROBE

Publications (2)

Publication Number Publication Date
GB2108133A true GB2108133A (en) 1983-05-11
GB2108133B GB2108133B (en) 1983-10-05

Family

ID=6060045

Family Applications (2)

Application Number Title Priority Date Filing Date
GB8000176A Expired GB2040472B (en) 1979-01-04 1980-01-03 Apparatus for measuring the rate of flow of a medium
GB08215541A Expired GB2108133B (en) 1979-01-04 1982-05-27 Electrical gas discharge polymerization method of coating a resistor

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB8000176A Expired GB2040472B (en) 1979-01-04 1980-01-03 Apparatus for measuring the rate of flow of a medium

Country Status (4)

Country Link
JP (1) JPS5593021A (en)
DE (1) DE2900200A1 (en)
FR (1) FR2445952B1 (en)
GB (2) GB2040472B (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0132684A1 (en) * 1983-07-22 1985-02-13 Siemens Aktiengesellschaft Process for preparing layers of polymerisates by glow discharge
EP0132686A1 (en) * 1983-07-22 1985-02-13 Siemens Aktiengesellschaft Process for preparing layers of polymerisates by glow discharge
EP0235362A2 (en) * 1986-03-03 1987-09-09 VDO Adolf Schindling AG Apparatus for measuring fluid-flow velocity
US6551950B1 (en) 1997-06-14 2003-04-22 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Surface coatings
US6653247B2 (en) 1999-02-26 2003-11-25 Trikon Holdings Limited Dielectric layer for a semiconductor device and method of producing the same
US7309662B1 (en) 1999-06-26 2007-12-18 Aviza Europe Limited Method and apparatus for forming a film on a substrate
USRE43651E1 (en) 1997-06-14 2012-09-11 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Surface coatings
EP1939593A3 (en) * 2001-02-28 2012-11-21 Hitachi, Ltd. Thermal flow rate measuring device
US8389070B2 (en) 2004-03-18 2013-03-05 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Coating of a polymer layer using low power pulsed plasma in a plasma chamber of a large volume

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6013220A (en) * 1983-07-04 1985-01-23 Esutetsuku:Kk Gas flow sensor and manufacture thereof
JPS60236025A (en) * 1984-05-09 1985-11-22 Nippon Soken Inc Air flow rate sensor
JPS62123318A (en) * 1985-08-13 1987-06-04 Nippon Soken Inc Direct heat type flow rate sensor
DE3838466C2 (en) * 1988-01-16 1995-11-16 Bosch Gmbh Robert Air mass measuring device and method for producing an air mass measuring device
JP2860126B2 (en) * 1989-12-26 1999-02-24 メージャーメント・テクノロジー・インターナショナル Fluid flow meter
JP2740620B2 (en) * 1993-06-01 1998-04-15 シーケーディ株式会社 Thermal flow meter
EP1083412A1 (en) 1999-09-07 2001-03-14 Endress + Hauser Gmbh + Co. Device for determining a physical quantity of a fluid or a solid material

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1010304B (en) * 1955-12-19 1957-06-13 Vyzk A Zkusebni Letecky Ustav Measuring body for measuring the flow velocities of a medium
CH510873A (en) * 1969-07-08 1971-07-31 Mettler Instrumente Ag Electric resistance thermometer
NL7202331A (en) * 1972-01-24 1973-07-26
US3991613A (en) * 1975-03-10 1976-11-16 Corning Glass Works Sensing element for flow meter
DE2537416B2 (en) * 1975-08-22 1977-06-30 Robert Bosch Gmbh, 7000 Stuttgart METHOD AND DEVICE FOR THE PRODUCTION OF A PROTECTIVE LAYER ON THE SURFACE OF OPTICAL REFLECTORS
DE2625448C3 (en) * 1976-06-05 1986-11-13 Robert Bosch Gmbh, 7000 Stuttgart Method and device for producing a protective layer on the surface of optical reflectors

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0132684A1 (en) * 1983-07-22 1985-02-13 Siemens Aktiengesellschaft Process for preparing layers of polymerisates by glow discharge
EP0132686A1 (en) * 1983-07-22 1985-02-13 Siemens Aktiengesellschaft Process for preparing layers of polymerisates by glow discharge
EP0235362A2 (en) * 1986-03-03 1987-09-09 VDO Adolf Schindling AG Apparatus for measuring fluid-flow velocity
EP0235362A3 (en) * 1986-03-03 1988-07-20 Vdo Adolf Schindling Ag Apparatus for measuring fluid-flow velocity
US6551950B1 (en) 1997-06-14 2003-04-22 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Surface coatings
USRE43651E1 (en) 1997-06-14 2012-09-11 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Surface coatings
US6653247B2 (en) 1999-02-26 2003-11-25 Trikon Holdings Limited Dielectric layer for a semiconductor device and method of producing the same
US6846757B2 (en) 1999-02-26 2005-01-25 Trikon Holdings Limited Dielectric layer for a semiconductor device and method of producing the same
US7309662B1 (en) 1999-06-26 2007-12-18 Aviza Europe Limited Method and apparatus for forming a film on a substrate
EP1939593A3 (en) * 2001-02-28 2012-11-21 Hitachi, Ltd. Thermal flow rate measuring device
US8389070B2 (en) 2004-03-18 2013-03-05 The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland Coating of a polymer layer using low power pulsed plasma in a plasma chamber of a large volume

Also Published As

Publication number Publication date
GB2108133B (en) 1983-10-05
FR2445952B1 (en) 1986-03-14
GB2040472B (en) 1983-05-25
DE2900200A1 (en) 1980-07-17
GB2040472A (en) 1980-08-28
FR2445952A1 (en) 1980-08-01
JPS5593021A (en) 1980-07-15

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PCNP Patent ceased through non-payment of renewal fee