Electrical resistors – Resistance value responsive to a condition – Current and/or voltage
Patent
1993-02-12
1995-04-11
Lateef, Marvin M.
Electrical resistors
Resistance value responsive to a condition
Current and/or voltage
338 25, 338307, 338314, 29612, H01C 710, H01C 1012
Patent
active
054062462
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a temperature sensor, particularly a PTC temperature sensor of the generic type and a method for producing a temperature sensor.
2. Background Information
It is generally known for temperature sensors having temperature sensor elements made of temperature-resistant resistance materials having a temperature-dependent resistance value to be used (cf. E. D. Macklen, "Thermistors" Verlag Electrochemical Publications [Electrochemical Publications Press], Ltd., 1979) for measuring relatively high temperatures such as those which prevail in the exhaust gases of internal-combustion engines.
PTC temperature sensors use the continuous resistance change of metals or semiconductors having a positive temperature coefficient when temperatures change. The metals which are preferably used in PTC temperature sensors are platinum and nickel, as well as their alloys, because of their high stability and reproducibility.
It is furthermore known, for example from EP-A 0,188,900 and 0,142,993, and DE-OS 3,017,947 and 3,543,759, for planar exhaust gas sensors to be used in order to determine the lambda value of gas mixtures, which exhaust-gas sensors can be produced in a particularly cost-effective manner using ceramic-film and screen-printing technology.
It is known from DE-PS 3,733,192 for the aging resistance and the response times of PTC temperature sensors to be improved by hermetically encapsulating the PTC temperature sensor elements with respect to the gas being measured and the environmental air.
It is a disadvantage of the known PTC temperature sensor elements that they have a certain area extent and are thus not subjected to the same exhaust-gas temperature at all points.
SUMMARY OF THE INVENTION
The temperature sensor according to the invention, in contrast has the advantage that sufficiently high measurement resistance values can be achieved by means of a stack arrangement, with a small area extent at the same time, and hence a high level of independence from the temperature gradient in the exhaust gas.
Advantageous developments and improvements of the temperature sensor element are possible. It is particularly advantageous to construct the films A and B from a ceramic on an aluminium-oxide base, and all the conductive elements, that is to say resistor tracks 10, 20, 30, supply leads 11, 21, 31, contacts 12, through-plated holes 14, and lands 15, 16 on a platinum/aluminium-oxide cermet paste. It is furthermore advantageous, and contributes to an area extent which is as small as possible, to construct the resistor tracks 10, 20, 30 in a meandering shape. The construction according to the invention and the claimed production method are particularly suitable for highly compact PTC thermistor temperature sensors in the field of application of high temperatures, as occur in the exhaust gases of internal-combustion engines. In addition to PTC temperature sensors, NTC (Negative Temperature Coefficient) temperature sensors can also be produced utilizing the same advantages in the manner according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Two exemplary embodiments of the invention are explained in greater detail in the following description and are shown in the drawing, in which:
FIG. 1 shows a first exemplary embodiment of a PTC temperature sensor having a double stack arrangement of the resistor tracks; and
FIG. 2 shows a second exemplary embodiment of the invention having a triple stack arrangement of the resistor tracks.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The method for producing a first embodiment according to the invention of a PTC temperature sensor element consisting of two Al.sub.2 O.sub.3 ceramic films has been shown schematically in FIG. 1. Two films having a thickness of 0.3 mm in each case were used. Holes 14 for through plating were initially stamped in the film A. A platinum/aluminium-oxide paste was sucked in through the holes in order to introduce the through-plated holes. A resistor track 10 in a
REFERENCES:
patent: 4345465 (1982-08-01), Gruner
patent: 4418329 (1983-11-01), Gruner
patent: 4464646 (1984-08-01), Burger et al.
patent: 4502939 (1985-03-01), Holfelder et al.
patent: 4645552 (1987-02-01), Vitriol et al.
patent: 4818363 (1989-04-01), Bayha et al.
patent: 4839018 (1989-06-01), Yamada et al.
patent: 4901051 (1990-02-01), Murata et al.
patent: 5142266 (1992-08-01), Friese et al.
patent: 5172466 (1992-12-01), Friese et al.
patent: 5181007 (1993-01-01), Friese et al.
E. D. Macklen, "Thermistors", Electrochemical Publications Limited, 1979, Introduction, pp. 1-15, Chapter 8, High Temperature and Other Unusual Forms of NTC Thermistor, pp. 139-146.
Friese Karl-Hermann
Neumann Harald
Lateef Marvin M.
Robert & Bosch GmbH
LandOfFree
Temperature sensor and method for producing temperature sensor e does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Temperature sensor and method for producing temperature sensor e, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Temperature sensor and method for producing temperature sensor e will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1541477