Temperature Sensor

Abstract

The present invention provides a temperature sensor, which has a thermistor material layer, the said thermistor material layer can reduce the influence of heat conduction from external wiring, and it is not easy to crack when it is bent, and can not be fired. And directly form a film on the film. It has: an insulating film (2); a thin film thermistor part (3), which is formed on the surface of the insulating film with TiAlN thermistor material; a pair of comb electrodes (4), which have A plurality of comb portions (4a), and patterned with metal facing each other; and a pair of pattern electrodes (5), connected to a pair of comb electrodes, and patterned on the surface of the insulating film, at least a part of the pattern electrodes Made of conductive resin.

Description

technical field [0001] The present invention relates to a temperature sensor, which is a film-type thermistor temperature sensor that is less susceptible to the influence of heat conduction from external wiring. Background technique [0002] In thermistor materials used in temperature sensors and the like, a high B constant is required for high accuracy and high sensitivity. Conventionally, transition metal oxides such as Mn, Co, and Fe have been generally used as such thermistor materials (see Patent Documents 1 and 2). In addition, in order to obtain stable thermistor characteristics among these thermistor materials, firing at 600° C. or higher is required. [0003] Also, in addition to the thermistor material composed of the above-mentioned metal oxide, for example, Patent Document 3 proposes a thermistor material composed of a nitride represented by the general formula: M x A y N z (Wherein, M represents at least one of Ta, Nb, Cr, Ti and Zr, A represents at least on...

AI Technical Summary

Problems solved by technology

However, when the temperature of the outer mold resin is higher than the temperature of the thermistor material layer, the lead-out electrode part of a metal with a large thermal conductivity (for example, Cu: 400W / m·K, Au: 318W / m·K) generates Due to the heat transfer phenomenon, it may affect the temperature accuracy. Therefore, for thermal insulation, it is necessary to set the wiring of the lead-out electrode part to be very long.

Therefore, there is a problem that the overall size becomes large and miniaturization is difficult

In particular, since it is a film type in which an insulating film is used as a substrate, the heat conduction on the film side is low compared to the case of wiring on another insulating substrate such as alumina, and there is a possibility that heat transfer from the external wiring via the lead-out electrode part adverse conditions where the influence of heat is relatively large

[0013] On the other hand, in the conventional thermistor material layer made of TiAlN, when the radius of curvature is large and it is bent slowly, it is difficult to generate cracks and there is no change in electrical characteristics such as resistance value, but when the radius of curvature is small and it is bent sharply, Cracks are likely to occur, and the resistance value changes greatly, resulting in a decrease in the reliability of electrical characteristics.

In particular, when the thin film is sharply bent in a direction perpendicular to the direction in which the comb extends with a small radius of curvature, compared to bending in the direction in which the comb extends, due to the difference in stress between the comb electrode and the thermistor material layer, Cracks are likely to occur near the edge of the electrode, which may degrade the reliability of electrical characteristics

[0014] In addition, the heat-resistant temperature of a film made of resin material is generally as low as 150°C or less, and even polyimide, which is well-known as a material with a relatively high heat-resistant temperature, has a heat resistance of only about 300°C. It is difficult to apply heat treatment during the formation process of the thermistor material

In the above-mentioned conventional oxide thermistor materials, in order to realize the desired thermistor characteristics, firing at 600°C or higher is required, and there is a problem that a thin-film thermistor sensor directly deposited on a thin film cannot be realized.

Therefore, it is desired to develop a thermistor material that can be directly formed into a film without firing. The film is heat-treated at 350-600°C

In addition, among the thermistor materials, in the examples of Ta-Al-N-based materials, materials with a B constant of about 500 to 3000K can be obtained, but there is no description about heat resistance, and it is not known that the nitride-based Material Thermal Reliability

Images