Coating processes – Measuring – testing – or indicating
Patent
1997-02-28
1998-12-29
Beck, Shrive
Coating processes
Measuring, testing, or indicating
4271265, 427375, 4273766, 4273767, 4273835, 427404, B05D 512, B05D 302, B05D 138
Patent
active
058537937
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The present invention refers to a method for producing a sensor for sensing a temperature and/or a flow.
BACKGROUND OF THE INVENTION
Sensors used for sensing a temperature and/or a flow and comprising a carrier and a structured resistance layer on said carrier are already known from the prior art. In the case of these known sensors, the resistance layer comprises e.g. a pure platinum layer having arranged thereon additional layers. In view of the structure described hereinbefore, these known sensors permit only a very inexact adjustment of a predetermined temperature coefficient. This results in instable temperature coefficient values so that the measured values detected are not reliable due to this instability.
The Patent Abstracts of Japan, Vol. 12, No. 220 (P-720) discloses a sensor consisting of a ceramic carrier and a resistance layer of Pt-Rh. The resistance layer is produced by applying a Pt-Rh paste to a substrate with the aid of screen printing and subsequent burning.
The Patent Abstracts of Japan, Vol. 17, No. 81 (E-1321) discloses the measure of producing a uniform resistance layer from a paste. The starting material used is a solution of at least one organo-metallic compound. Rh-Pt compounds are mentioned among other compounds.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a process for producing a sensor which permits an exact adjustment of the temperature coefficient of said sensor.
The present invention provides a method for producing a sensor which is used for sensing a temperature and/or a flow and which comprises a carrier and a structured resistance layer arranged on said carrier, comprising the following method steps: resinate paste; onto an aluminium oxide substrate; resinate component contained in the layer will be burnt out; a desired overall layer thickness has been obtained; and stable temperature coefficient.
The present invention is based on the finding that, instead of the plurality of layers used in the prior art, viz. the platinum layer having applied thereto additional layers, a single layer is more suitable for adjusting the temperature coefficient. This resistance layer contains a mixture of platinum and rhodium, whereby an exact adjustment of the temperature coefficient is possible.
BRIEF DESCRIPTION OF THE DRAWING
In the following, one preferred embodiment of the present invention will be explained in detail making reference to the drawing enclosed, in which:
FIG. 1 shows a sectional view of a sensor for sensing a temperature and/or a flow according to one embodiment of the present invention.
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
FIG. 1 discloses a sensor 100 for sensing a temperature and/or a flow. This sensor comprises a substrate 102 consisting preferably of aluminium oxide having a purity of 96.5% to 99.5%, the rest of said substrate consisting of other oxides; said substrate 102 has arranged thereon a structured resistance layer 104. The resistance layer is a platinum-rhodium layer.
For producing the platinum-rhodium layer, a mixture consisting of a platinum resinate paste and of a rhodium resinate paste is used as a starting material. The platinum resinate paste contains 12% by weight of platinum, the rest of the paste consisting of an organic substance, and the rhodium resinate paste contains 7% by weight of rhodium, the rest of the paste consisting again of an organic substance.
In accordance with the preferred embodiment, these two pastes are mixed, a platinum-rhodium layer having a temperature coefficient of 3500 ppcm/.degree.C. being obtained by mixing 99% of platinum resinate paste and 1% of rhodium resinate paste, when the method steps following hereinbelow are performed. onto an aluminium oxide substrate having a layer thickness of approx. 15 .mu.m; a period of 10 minutes; approx. 800.degree. C., whereby the layer thickness of the platinum-rhodium layer will be reduced to approx. 0.12 .mu.m after the first burning, i.e. a large amount of the organic substance has been burnt
REFERENCES:
patent: 4146957 (1979-04-01), Toenshoff et al.
patent: 4288774 (1981-09-01), Takami et al.
patent: 4430191 (1984-02-01), Sone et al.
patent: 4655892 (1987-04-01), Satta et al.
patent: 4688015 (1987-08-01), Kojima et al.
patent: 4808274 (1989-02-01), Nguyen
patent: 5008136 (1991-04-01), Chamberlain
patent: 5236569 (1993-08-01), Murase et al.
patent: 5250394 (1993-10-01), Wei
Elektrotechnik Und Maschinebau, Bd. 103, Nr. 1, Januar 1985 Wiet AT, Seiten 22-26, T.F.E. Walla et al. "Dickschichttemperatursensoren" siehe Seite 23.
Patent Abstracts of Japan, vol. 12 No. 220 (P-270), 23 Juni 1988 & JP,A,63 016255 (Fuji Electric Co. Ltd) 23 Januar 1988, Siehe Zusammenfassung.
Patent Abstracts of Japan, vol. 17 No. 81 (E-1321), 18 Februar 1993 & JP,A,04 279003 (Fuji Xerox Co. Ltd) 5 Oktober 1992, Siehe Zusammenfassung.
Barr Michael
Beck Shrive
Sensotherm Temperatursensorik GmbH
LandOfFree
Method for producing a sensor for sensing a temperature and/or a does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing a sensor for sensing a temperature and/or a, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing a sensor for sensing a temperature and/or a will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1422208