JPH10142073A - Resistance type temperature sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat resistance, environmental resistance, and heat and shock resistance and to detect a temperature ranging from a room temperature to a high temperature quickly by laminating a number of metal silicide temperature-sensing resistor layers and alumina thickness layers and hence constituting a temperature-sensing resistor circuit. SOLUTION: For example, a resistance material composed of 90vol.% MoSi2 and 10vol.% Al2 O3 and an insulation material where 3wt.% Mg0 and 0.3wt.% SiO2 are added to a basic composition consisting of 90vol.% Al2 03 and 10vol.% mullite are generated, and these paints are applied to a polyethylene film to obtain a resistor sheet and an insulator sheet. Then, an insulation part 3 where an insulator sheet is laminated is sandwiched by connection terminals 1 and 2 where the resistor sheet is laminated, a thermally sensitive part 6 is connected between conductive parts 4 and 5 that are connected to the terminals 1 and 2, thus constituting a resistance type temperature sensor. Since the thermally sensitive part 6 is formed with a metal silicide having a small thermal coefficient of expansion as a main body, a sufficient heat and shock resistance can be obtained even if it is combined with Al2 O3 , with a small thermal coefficient of expansion as a main constituent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance type temperature sensor for detecting the temperature of a high-temperature atmosphere such as automobile exhaust gas, an oil stove, and a gas stove.

[0002]

2. Description of the Related Art In a temperature sensor for detecting a high temperature in a short time, it is required that the temperature sensor be excellent in heat resistance, environment resistance, thermal shock resistance and small in heat capacity. In other words, even if the temperature sensor is exposed to the high temperature for a long period of time, the temperature sensor is unlikely to undergo chemical change, and has sufficient corrosion resistance to corrosive gases such as sulfur oxides present in automobile exhaust gas and fuel combustion gas. Is required.

Conventionally, a thermocouple sensor or a resistance type temperature sensor has been used as a sensor for detecting a high temperature.
There is no one that has quick response and excellent heat resistance and environmental resistance. Therefore, when a temperature-sensitive material that does not have sufficient heat resistance and environmental resistance is used, its surface is coated with a heat-resistant and environment-resistant material.

In general, in applications in which a high temperature is detected in a short time, a temperature sensor may be installed in an environment where there is a sudden change in temperature, and the temperature is detected. Therefore, the temperature sensor has excellent thermal shock resistance. Must be composed of material. Also,
In order for the temperature of the temperature sensing section to follow the temperature change of the environment in a short time, the heat capacity of the temperature sensing section needs to be as small as possible.

Heretofore, a heat-resistant metal or metal compound such as tungsten (W) or platinum (Pt) has been used as a material of the temperature-sensitive part, but a heat-resistant metal such as tungsten or platinum is thermally expanded. When a ceramic having a small thermal expansion coefficient is used for a container or the like because of its large coefficient, the reliability is low in terms of thermal shock resistance.

On the other hand, a resistance type temperature sensor in which a thermistor made of a metal oxide is used in place of metal as a material of a temperature sensing part and a thermistor layer is formed on a ceramic substrate is disclosed in Japanese Unexamined Utility Model Publication No.
Japanese Patent Application Laid-Open No. Hei 7-190 discloses a temperature sensor in which a cermet, which is a mixture of metal and ceramic, is used and a cermet layer is formed on a ceramic substrate.
No. 863, all of which are 1,1.
Does not have heat resistance at a temperature of 000 ° C. or higher.

In order to improve the responsiveness of the measurement result of the temperature sensor to the temperature, it is necessary to secure the temperature followability by reducing the heat capacity of the temperature sensing part. Then, in order to reduce the heat capacity of the temperature sensing part, the shape and size of the temperature sensing part may be reduced. However, when a temperature sensor is used in a harsh environment such as an automobile engine, the mechanical strength to withstand vibration and impact during operation of the device and the assembling of the temperature sensor to such a device are strong. Therefore, mechanical strength that does not hinder the assembly process is required. However, in a temperature sensor formed by forming a thermistor layer or a cermet layer on a ceramic substrate, the temperature-sensitive portion is formed on a ceramic substrate that requires a certain size, so that the entire temperature-sensitive portion is formed. There is a limit to miniaturization of the shape and dimensions, and thus a limit to the reduction of heat capacity. As described above, in the related art, no temperature sensor has been able to detect the temperature in a short time over a temperature range from room temperature to a high temperature of 1,000 ° C. or more.

[0008]

SUMMARY OF THE INVENTION The invention of the present application is capable of detecting a temperature within a short time of 5 seconds or less in a temperature range from room temperature to about 1,000 ° C. to about 1,300 ° C. An object of the present invention is to provide a resistance-type temperature sensor that has excellent resistance and environmental resistance and can withstand long-term use.

[0009]

In order to solve the above problems, in the present application, a metal silicide, which is a conductive ceramic having a thermal expansion coefficient as low as that of alumina used as an insulating substrate, is used as a temperature-sensitive resistor. Further, a resistance type temperature sensor in which a temperature-sensitive resistor circuit is formed by laminating a large number of metal silicide temperature-sensitive resistor layers and alumina thick film layers used as a conductor is provided.

As the metal silicide used for the temperature-sensitive resistance material, molybdenum silicide having the same thermal expansion coefficient as that of an alumina insulating substrate is optimal, and an insulator such as alumina or mullite is mixed with the temperature-sensitive resistance material. Thereby, the resistance value can be adjusted. Further, the temperature-sensitive resistance portion of the laminate is formed thinner than other portions.

[0011]

According to the temperature sensor of the present invention, the material of the temperature sensing portion is mainly composed of a metal silicide such as molybdenum silicide (MoSi ₂ ) having a small thermal expansion coefficient, so that alumina (Al ₂ O ₃ ) having a small thermal expansion coefficient is used. A sufficient thermal shock resistance can be obtained even in combination with an insulating ceramic material containing ()) as a main component. Further, by forming the base with an alternate laminated structure of a conductor material mainly composed of a metal silicide such as molybdenum silicide and an insulating ceramic material mainly composed of alumina, as a result, an insulating ceramic material mainly composed of alumina is obtained. It is possible to realize a substrate having excellent thermal shock resistance, which hardly impairs the thermal shock resistance of a conductive material mainly composed of a metal silicide such as molybdenum silicide having superior thermal shock resistance.

[0012]

EXAMPLES In describing specific examples of the present invention,
The entire invention will be described. [Basic Structure] The structure of the resistance type temperature sensor of the present invention is formed in a laminated structure. Due to this, if it is necessary to make the structure of the temperature sensitive part thinner than the thickness of the surrounding body,
Since the structure of the present invention can be easily formed by punching and laminating a portion of the material forming the base in the step of forming the temperature sensor element and punching out the portion located in the temperature-sensitive portion, it can be manufactured in almost the same manufacturing process. It is.

The element of the present invention has a structure in which two kinds of materials are formed into a thick film of the same layer. In such a structure, a thick film is formed by a sheet method in which there is little variation in the thickness dimension of the whole film. .

The temperature sensing portion is formed by a circuit of a temperature sensing resistor. In the temperature sensing resistor circuit, an insulating thick film layer is provided between the temperature sensing resistor layers composed of thick film layers, The resistor thick film layers are connected to each other by a conductor.

In order to realize the function of the resistance type temperature sensor of the present invention, a connection part for transmitting a measurement signal to an external processing circuit and a structure for holding and mounting the resistance type temperature sensor are required. Since the resistance type temperature sensor of the present invention is intended to measure a high temperature, these structures naturally need design specifications taking heat resistance into consideration.

In the resistance type temperature sensor of the present invention, a terminal connection portion for external connection is provided at an end opposite to the temperature sensing portion of the temperature sensor element, and a lead member is formed by applying nickel plating to this portion. The electrical connection between the resistance-type temperature sensor element and the lead member is achieved by soldering with silver brazing or welding to realize a connection structure having heat resistance and mechanical strength. be able to.

In the resistance type temperature sensor of the present invention, the resistance type temperature sensor element is inserted into a heat resistant tube such as a ceramic tube mainly composed of alumina, and is filled with a heat resistant filler such as ceramic cement. The element is held and fixed. With this structure, necessary heat resistance is realized.

[Material] The resistance type temperature sensor element of the present invention comprises a temperature sensing part for detecting temperature, a connection part for connecting the element to an external circuit, and a conductive part for electrically connecting the temperature sensing part and the connection part. Is done. These temperature-sensitive parts, conductive parts and connection parts are all formed by forming ceramic in a laminated structure, and a resistance material in the laminated structure and constituting the temperature-sensitive part,
The conductive material forming the conductive portion and the connection portion needs to be electrically separated appropriately by an insulating material in order to form an electric circuit. Therefore, in the present invention, a ceramic temperature-sensitive resistance material, a ceramic conductive material, and a ceramic insulating material are used.

The insulation resistance required for the insulating material is desirably 100 MΩ or more and at least 1 MΩ. The insulating material made of alumina is 10 ¹⁰ Ω ·
Since it exhibits a specific resistance of about cm, the dimensions of the temperature-sensitive portion are representative dimensions of the present invention, which will be described later: width = 1.2 mm, length = 6 m
When m and the layer thickness are 35 μm, an interlayer insulation resistance of 3 × 10 ¹² Ω is obtained, and it can be said that this is an insulator material suitable for use in the present invention.

The resistance value of the temperature-sensitive resistor portion is such that when the resistance value ratio with the insulator is approximately 1,000, the leakage current value is 1/1000.
Therefore, it is possible to measure the temperature with practical accuracy. If the resistance value of the temperature-sensitive resistor is several tens KΩ or more,
The measurement current is very small at a practical measurement voltage, and there is a difficulty in maintaining the measurement accuracy. For this reason, it is desirable that the resistance value of the temperature-sensitive resistor section be several KΩ or less. in this way,
In the case of realizing a resistance value of, for example, 1 KΩ with the above-described typical temperature-sensitive portion dimensions of the present invention, the specific resistance of the resistor is about 0.3 Ω · cm. This specific resistance can be obtained by setting the composition of molybdenum silicide, one of the metal silicides, to 30% by volume or more based on alumina. In order to obtain a predetermined resistance value of the temperature sensing portion, the resistance value can be adjusted by mixing an insulating material such as alumina or mullite with a resistance material.

The resistance value of the conductive portion and the connection portion is the same as that of the insulating portion.
/ 1,000, it is possible to obtain a resistance value, for example, several Ω, at which the temperature can be measured with practical accuracy. The specific resistance for realizing a resistance value of, for example, 1 Ω in the above-described typical temperature-sensitive portion dimensions of the present invention is about 3 × 10 ⁻⁴ Ω · cm. This specific resistance can be obtained when the composition of molybdenum silicide is 50% by volume. If the composition of molybdenum silicide is 50% by volume or more,
It is possible to obtain a resistance value of several Ω or less required for the conductive portion and the connection portion. The material of the conductive part may be made of the same material as the resistor of the temperature-sensitive part, but it is preferable that the resistance of the conductive part is lower than the resistance of the temperature-sensitive part.

Further, although thermal shock resistance is not so excellent when alumina alone is used, when a laminate is formed by combining molybdenum silicide having the same thermal expansion coefficient as alumina used as an insulating material with alumina. Sufficient thermal shock resistance can be ensured.

Although the main materials used in the present invention are molybdenum silicide and alumina, it is necessary to control the sintering reaction during firing in a desirable state in order to form a dense sintered body. In a metal silicide such as molybdenum silicide, a metal component such as molybdenum (Mo) evaporates and volatilizes due to decomposition, and silica (SiO ₂ ) which is an oxide of silicon (Si) as another compound component remains. The specific resistance of the conductor material varies depending on the amount of molybdenum evaporating. Therefore, the resistance value control requires strict management of the process conditions.

An insulator containing alumina as a main component is mixed for the purpose of controlling the specific resistance of the conductor material. Mullite (3Al ₂ O ₃ .2SiO ₂ ) is mixed with the remaining silica and alumina.
A system of compounds is produced. Even if a conductor material is formed without containing mullite as a raw material, there is no problem if strict control of process conditions is performed in order to form the temperature sensor of the present invention, but the inclusion of mullite suppresses the decomposition of molybdenum silicide. And the resistivity of the conductive material can be more easily controlled.

When magnesia (MgO) is contained in the component, cordierite (2MgO.Al ₂ O _3.
A 5SiO ₂ ) -based compound is generated, whereby the decomposition of molybdenum silicide can be suppressed as in the case of mullite, and the specific resistance of the conductive material can be more easily controlled. However,
If the mullite content exceeds about 15% by volume and the magnesia content exceeds about 5% by weight, sintering of the conductive material is hindered, and it becomes difficult to obtain a dense sintered body. The amount has an upper limit. In this case, mullite and magnesia may coexist or may be contained independently.

The insulator material needs to have strong adhesiveness to the conductor material. Therefore, the same composition as the insulator material contained in the conductor material is desirable. By containing silica, the adhesiveness is further improved, and a more preferable element body can be formed. However, when the content exceeds approximately 0.5% by weight, sintering of the insulator is hindered, and it becomes difficult to densify the sintered body.

Since the temperature-sensitive resistor portion and the conductive portion are covered with these dense ceramics, stability to the environment can be maintained. Further, after forming the temperature sensor element, by forming a fired film containing alumina or silica as a main component on the surface thereof, environmental resistance can be improved. This calcined film is made of alumina or silica by CVD (Chemical Vapou).
r Deposition), or by immersing and adhering to these slurries followed by firing.

[Manufacture of Materials] The properties required for the raw materials when manufacturing the ceramic laminate are that drying properties and viscosity are appropriate and that cracks and uneven drying are not generated when forming a thick film. That there is no problem in the smoothness of the surface. In order to realize the desired properties, the concentration of the coating material, the type and the amount of the binder to be added are appropriately selected according to the powder characteristics of the material. In addition, when it is necessary to form the elementary body by a sintering reaction in the firing step after forming the laminate, it is desirable to realize the optimal particle size distribution and the degree of dispersion at the time of producing the coating material of the material. .

Generally, in the case of a hardly sinterable material such as a metal silicide used in the present invention, the activity during sintering is increased by pulverizing the material sufficiently finely, and the activity is lowered. Sintering at the sintering temperature becomes possible. However, the manufacturing conditions of the material for achieving the optimum particle size distribution and the degree of dispersion and the optimum manufacturing conditions of the coating material are often different, so that appropriate powder characteristics are obtained before manufacturing the coating material. It is necessary to pre-process the material.

In the case of the metal silicide used in the present invention, if the fine pulverizing treatment for increasing the activity is performed in air, the metal and silicon constituting the metal silicide are easily oxidized. In many cases, the pretreatment conditions generally include a higher solvent concentration than the paint production conditions, that is, a lower slurry concentration. Therefore, in the pretreatment step, it is necessary to dry the material after the pulverization, and then to prepare the material constituting the paint again so as to have a predetermined paint composition.

In the case of the metal silicide used in the present invention, as described above, in the handling of the material after the pre-treatment, in order to prevent oxidation, the material is handled in a non-oxidizing atmosphere such as vacuum or nitrogen, or a solvent component. If any residue remains, care must be taken to prevent ignition due to heat generated by oxidation. According to the method for producing a material of the present invention, the above-mentioned problems are solved and the steps are shortened.

That is, after pulverizing under the optimum pulverizing conditions, a solvent is partially removed by a concentrator such as a vacuum deaerator or a filter press, and then, a coating material such as a insufficient binder and a plasticizer is blended and optimized. To produce paints of the following properties: As a result, finely pulverized material powder having high activity is handled as a solvent slurry, so that oxidation in the air and ignition due to oxidation can be prevented, and the drying process and storage for preventing oxidation are performed. The steps can be omitted. Further, since the slurry viscosity in the pulverization step can be made lower than the viscosity of the paint, the material can be recovered with a high yield when the material is taken out from a dispersion device such as a ball mill or a media mill, and when the material is separated from the medium. .

[Firing Conditions] Since the element laminate of the present invention contains a so-called hardly sinterable metal silicide as a constituent component, it is fired at a temperature of at least 1,200 ° C., preferably 1,400 ° C. or more. There is a need. The metal silicide is 2
Since it is oxidized in the air even in a low temperature range of about 00 degrees, it is necessary to fire in a non-oxidizing atmosphere. The non-oxidizing atmosphere is preferably an argon gas atmosphere, and the nitrogen atmosphere is not preferable because the metal silicide tends to be nitrided, and as a result, the temperature characteristics of the resistance change.

Since the metal silicide is easily oxidized in air, the oxidation of the metal silicide lowers the stability of its performance under the actual use conditions of the temperature sensor element of the present invention, and It needs to be suppressed. For this purpose, it is desirable to increase the density of the sintered body after sintering as much as possible. In order to increase the density of the sintered body after the sintering, a part of the heating process, or a part of the heating process and a part of the stable part, is set to a degree of vacuum of 50 Torr or more, preferably 10 Torr or more. The density of the sintered body can be increased. The effect of vacuuming a part of the firing process is that when sintering progresses and the pores of the crystal structure become closed pores due to densification, when the degree of vacuum in the firing atmosphere is high, the inside of the closed pores also When the degree of vacuum is high and the densification further proceeds, the closed pores disappear and high density is achieved.

When the degree of vacuum in all the firing steps is high,
Evaporation of components, especially silica, is remarkable and is not preferred. Also,
Firing by applying pressure during the firing process is preferable because it promotes densification. The pressure firing may be so-called hot press firing, HIP (Hot Isostatic Pressing) firing, or any other pressure firing. However, since pressure firing is more expensive than normal pressure firing, if the desired densification can be achieved by normal pressure firing, it does not go beyond that.

Firing at a temperature exceeding 1,800 ° C. is close to the melting point of a ceramic base containing alumina as a main component. Specifically, a part of the ceramic base is melted or evaporated to disappear, or metal silicide is used. It is difficult to react with a substance and form a target structure, which is not preferable.

[Production of Laminated Body] The thick film layer constituting the laminated body is formed by coating a coating of a material having predetermined characteristics on a polyethylene film and drying it to remove unnecessary portions. A thick film layer having a partially different characteristic is formed by embedding a thick film layer of a material having the characteristics described above in a portion where unnecessary portions are removed, and the thick film layers thus formed are sequentially laminated. Manufactured by Further, it can also be manufactured by applying a paint thick film of a material having predetermined characteristics on a polyethylene film, drying, cutting to a required size and combining.

Next, the structure of the temperature sensor according to the embodiment of the present invention will be described with reference to the drawings. [Embodiment 1] FIG. 1 is a diagram showing a laminated structure of a resistance type temperature sensor element according to Embodiment 1 of the present invention.
The pattern is shown as 100mm long and 80m wide
m, 35 μm thick and 9 types of thick film layers are ABCC-
(D-E-D-F-D-F-D-F-D-F-G-H-I-
HGDFDEDFDEDED) -C-
A total of 29 layers are laminated in the order of BA, and the temperature sensor layer is composed of 21 thick films shown in parentheses excluding the thick films of the patterns A, B, and C at both ends. . Note that the partition between the same layers shown in FIG. 1 has disappeared after sintering. In the embodiment shown in FIG. 1, the number of layers is reduced to facilitate the description of the invention. Actually, the resistance type temperature sensor element having 89 layers shown in FIG. used.

In the resistance type temperature sensor laminated in such a structure, connection terminals 1 and 2 in which a resistance material is laminated with an insulating portion 3 in which an insulation material is laminated are formed, and these connection terminals 1 and 2 are formed. 2, conductive portions 4 and 5 are connected, and a temperature sensing portion 6 is connected between the conductive portions 4 and 5. In addition, protective layers 7 and 8 are provided on the upper and lower surfaces of the temperature sensing unit 6.

The conductive portion 4 is formed by the resistor 9 of the pattern B and the resistor 10 of the pattern C. The conductive portion 5 is formed by the resistor 10 of the pattern C and the resistor 9 of the pattern B. Resistor 11, pattern E resistor 12, pattern D resistor 11, pattern F resistor 13, pattern D resistor 11, pattern E resistor 12, pattern D resistor 11, pattern F resistor Resistor 13, Resistor 11 of Pattern D, Resistor 1 of Pattern G
4, resistor 15 of pattern H, resistor 1 of pattern I
6, resistor 15 of pattern H, resistor 1 of pattern G
4, resistor D of pattern D, resistor 1 of pattern F
3, resistor D of pattern D, resistor 1 of pattern E
2, resistor D of pattern D, resistor 1 of pattern F
3, resistor D of pattern D, resistor 1 of pattern E
2, formed by the resistor 11 of the pattern D.

Each thick film layer shown in FIG. 2 is composed of 90% by volume of molybdenum silicide and 10% by volume of alumina. 10% by volume mullite base composition with 3 more
The insulating materials indicated by white backgrounds in the figure, which are composed of a composition to which magnesia and 0.3% by weight of magnesia are added, are A to I
Is formed in a rectangular shape in combination with the pattern shown as.

A method for manufacturing the temperature sensor according to the first embodiment will be described. (1) Preparation of Material Molybdenum silicide having a particle size of 2 μm
A volume%, alumina having a particle size of 0.4 μm is made up to a composition of 10 volume%, and these raw materials, a methacrylic resin as a binder, toluene and ethanol as a solvent, and BPBG as a plasticizer are put into a pot made of alumina porcelain, and a dispersion medium. Was dispersed using alumina balls for 15 hours to obtain a resistor paint.

As the insulator material, 90% by volume of alumina having a particle size of 0.4 μm, 10% by volume of mullite having a particle size of 0.4 μm, 3% by weight of magnesia having a particle size of 0.4 μm, and 0.3% by weight.
4 μm silica was made into a composition of 0.3% by weight, and, like the resistor material, these raw materials, methacrylic resin as a binder, toluene and ethanol as a solvent, and BPBG as a plasticizer were put into an alumina porcelain pot and dispersed. Disperse for 15 hours using alumina balls as media,
Obtain insulation paint.

(2) Production of Sheet The resistor paint and the insulator paint produced in the above process were adjusted on a polyethylene film by adjusting the height of a doctor blade so that the thickness after drying was 35 μm by a sheet coater. Then, a thick film having a width of 80 mm is formed to obtain a resistor sheet and an insulator sheet. The formed resistor and insulator sheet are each cut into a length of 100 mm according to the stack size at the time of manufacturing a laminate.

(3) Production of Thick Film Layer Each thick film layer constituting the temperature sensor is composed of a resistor and an insulator. FIG. 3 shows a method of manufacturing a laminate by forming the thick film layer indicated by C in FIG. 2 on the thick film layer also indicated by D.

FIG. 6A shows a resistor sheet manufactured in the above-mentioned sheet manufacturing, and a resistor thick film 22 is applied on a polyethylene film 21. The cuts 23 and 24 shown by broken lines are made in the resistor thick film 22, and the resistor thick films between them are peeled off according to the cuts 23 and 24, leaving the resistor thick films 25 and 26. Get the material to be.

On the other hand, (c) shows an insulator sheet produced in the production of the above-mentioned sheet, and an insulator thick film 28 is applied on a polyethylene film 27. By making cuts 29 and 30 shown by broken lines in the insulator thick film 28 and leaving the insulator thick film 31 in accordance with the cuts 29 and 30, the outer insulator thick film is peeled off, as shown in FIG. Get the material.

Next, as shown in (e), the resistor sheet shown in (c) is turned upside down, and the resistor sheet is placed on the thick film layer 33 already formed as a pattern D on the polyethylene film 32. After applying a pressure of 0.1 kg / cm ² for 10 seconds, the polyethylene film 21 is removed.

Further, as shown in (f), the insulator material shown in (d) is turned upside down, and an insulator material is interposed between the resistor materials 25 and 26 laminated on the thick film layer D. The laminate is aligned and positioned so that the material 31 enters, a pressure of 0.1 kg / cm ² is applied for 10 seconds, and then the polyethylene film 27 is removed to obtain a laminate shown in (g). By performing a predetermined lamination according to the process, FIG.
Are obtained.

(4) Manufacture of the laminated body After the predetermined lamination is completed, the laminated body is removed from the stack substrate and put into a pressing mold, and a pressure of 1.5 kg / cm ² is applied to the stacking substrate.
Add for 2 seconds and pressurize.

(5) Cutting of the laminate Next, the laminate is attached to a cutting substrate to which a double-sided tape has been attached, and cut with a diamond blade at a pitch of 2.4 mm to obtain a laminate having a length of 50 mm and a width of 3 mm. .

(6) Production of Sintered Body The cut laminate is mounted on a substrate made of boron nitride, debindered at 600 ° C. for 2 hours in nitrogen gas, and then removed for 1 hour in argon gas. Calcination at 750 ° C., and 1.6 hours at 2,000 atmospheres argon gas for 2 hours.
HIP baking is performed at 50 ° C. After firing, 2 in air
A surface oxidation treatment is performed at 1,430 ° C. for a time.

(7) Connection Terminal Processing After the surface oxidation treatment, the stacked end face and the upper end member of the connection terminal section 1 and the stacked end face and the lower end member of the connection terminal section 2 shown in FIG.

Next, these connection terminals 1 and 2 are printed with a palladium catalyst for nickel plating, dried, heat-treated, and subjected to nickel electroless plating. FIG. 5A shows the resistance-type thermosensitive element body thus obtained. Note that this resistive thermosensitive element body is not the resistive thermosensitive element body shown in FIG. 1 but a thick film of the pattern shown in FIG. -D-F-D-E-D-F-D-
E-D-F-D-F-D-F-D-F-D-F-D-F-F-D-E
-D-F-D-F-D-F-D-F-D-F-F-D-F-
DFDEDFDHHIGHGH
-I-H-G-F-D-F-D-F-D-F-D-E-D-
F-D-E-D-F-D-F-D-F-F-D-F-E-D-F-F
-D-E-D-F-D-F-D-F-F-D-F-E-D-F-
DED) -CBA in the order of 89 layers.

(8) Assembly / Processing After cleaning and drying the connection terminals 1 and 2 to which the Ni electroless plating has been applied, the lead members 35 and 3 shown in FIG.
The connection terminals 1 and 2 of the resistive thermosensitive element body are held between the connection portions 37 and 38 of No. 6 and brazed with a nickel plating portion and silver braze.

The resistance type thermosensitive element body to which the lead members 35 and 36 are connected is inserted into an alumina tube 39 shown in FIG. 5C, and a ceramic cement 40 is formed as shown in FIG. And dried at 90 ° C. for 0.5 hour.
Heat treatment at 0 ° C. for 2 hours to cure.

Tables 1 and 2 show the measurement results of the electrical characteristics of the temperature sensor assembly of Example 1 thus obtained. Table 1 shows the change rate of the resistance value when the temperature is changed, when the resistance value itself is compared with the normal temperature (25 ° C.). Table 2 shows the results of measuring the response speed by immersion in a nitrite melt at 400 ° C. Sample A was cut at a pitch of 2.4 mm in the cutting step, while Sample B was cut at a pitch of 2.4 mm.
Is cut at a pitch of 1.2 mm, and sample C is 4.8 mm in width.
It is cut at the pitch.

[0058]

[Table 1]

[0059]

[Table 2]

FIG. 6 shows a graph of Table 1, and FIG. 7 shows a graph of Table 2.

According to Table 1 and the corresponding graph of FIG.
It is clear that the resistance value of each of the temperature sensors of Example 1 changes sufficiently with temperature change.

Further, according to Table 2 and the corresponding graph of FIG. 7, it is clear that the resistance value of each of the temperature sensors of Example 1 has changed to the expected value with a sufficient response speed.

[Embodiment 2] FIG. 8 is a (a) schematic structural view of a resistance temperature sensor element body according to Embodiment 2 of the present invention.
(B) shows a laminated structure similar to that of FIG. 1, and (c) shows patterns J and K of a thick film body newly adopted. These thick film patterns J and K are obtained by forming openings 41 and 42 in the thick film patterns A and B shown in FIG. 2, respectively.

In the resistance type temperature sensor element body shown in FIG. 7, these 11 types of thick film layers are formed by JKKJKKJKK.
-JKKJK- (ABEDFDDDED
-I-H-G-H-I-D-E-D-F-D-F-D-E-B-
A) It is constituted by laminating a total of 41 layers in the order of -KJKJKKKJKKJKJ, and ten thick films each having patterns J and K at both ends. The temperature-sensitive portion 43 is constituted by the 21 thick films shown in parentheses except for the parentheses, and a protective layer of pattern B is provided on the outermost portion of the temperature-sensitive portion 43,
Openings 44 and 45 are formed above and below the temperature sensing portion 43 by the openings 41 and 42 formed in the thick film patterns J and K.

By adopting such a structure, the thickness of the temperature-sensitive portion can be reduced even if the protective layer is thickened in order to secure the strength, so that the sensitivity of the temperature-sensitive portion is not reduced. Can be The manufacturing method and the measurement results will be described below, but the description of the parts common to the first embodiment will be omitted, and only the parts different from the first embodiment will be described.

A resistance material and an insulator material are prepared by the same composition and method as in Example 1 except that the composition of the resistance material is 40% by volume of molybdenum silicide and 60% by volume of alumina.

In manufacturing the laminate, a plurality of holes for forming the holes 41 and 42 are punched out in advance in the thick film layer indicated by the patterns A and B in FIG. The formed thick film layers A to K are laminated in a predetermined order according to the method described with reference to FIG. 3 to obtain a laminate. This laminate was placed in a pressing mold, and a pressure of 1.5 kg / cm ² was applied for 300 minutes.
After adding for 2 seconds, cut at a pitch of 4.8mm and length 50m
m, a laminate having a thickness of 3 mm is obtained.

The cut laminate is placed in a nitrogen gas at 600 ° C.
And then baking at 1700 ° C. for 2 hours in an argon gas, and further firing at 1,650 ° C. for 2 hours in an argon gas at 2,000 atm by the HIP method, followed by 1 hour in the air. The surface oxidation treatment is performed at 400 ° C. for 1 hour.

Tables 3 and 4 show the measurement results of the electrical characteristics of the temperature sensor assembly of Example 2 obtained as described above. Table 3 shows the rate of change of the resistance value when the temperature is changed, when the resistance value itself is compared with the room temperature (25 ° C.). The results shown in Table 4 are the results of measuring the response speed by immersion in a nitrite melt at 400 ° C. Sample D was cut at a pitch of 2.4 mm in the cutting step, and Sample E was cut.
Is cut at a pitch of 1.2 mm, and sample F is 4.8 mm in width.
It is cut at the pitch.

[0070]

[Table 3]

[0071]

[Table 4]

FIG. 9 is a graph of Table 3, and FIG. 10 is a graph of Table 4.

According to Table 3 and the corresponding graph of FIG.
It is clear that the resistance value of each of the temperature sensors according to the second embodiment changes sufficiently with respect to the temperature change.

Further, according to Table 4 and the corresponding graph of FIG. 10, it is clear that the resistance value of each of the temperature sensors of Example 2 changed to the expected value with a sufficient response speed.

Embodiment 3 The only metal silicide used in the embodiments described so far is molybdenum silicide, but various other metal silicides are known. Other metal silicides can also be used as the ceramic material constituting the resistance-type thermosensitive element.
Hereinafter, a case will be described in which a metal silicide other than molybdenum silicide is used as a ceramic material constituting a resistance-type thermosensitive element.

Various types of metal silicides are known, but the electrical properties, physical properties, and chemical properties differ depending on the metal constituting the silicide. In applications for temperature detection in a high-temperature atmosphere, those having excellent heat resistance and oxidation resistance in addition to the resistance temperature characteristics necessary for temperature detection are most desirable, and the maximum use temperature is 1,300 ° C. as in the present invention.
In the vicinity, silicides of molybdenum (Mo), tungsten (W), titanium (Ti), and tantalum (Ta) are suitable. Among them, silicide is considered when material prices, manufacturing difficulty, and the like are comprehensively determined. Molybdenum is preferred. But,
Even when a silicide of another metal such as tungsten silicide (WSi ₂ ) is used, it is possible to realize a resistance type temperature sensor that can sufficiently withstand use.

An example of a resistance type temperature sensor using tungsten silicide as a resistance material will be described below. This resistance type temperature sensor is the same as the second embodiment shown in FIG.
Since it has the same configuration as the resistance type temperature sensor described above, the description of the common parts will be omitted.

(1) Preparation of Material Tungsten silicide having a particle size of 3 μm was used as a resistor material.
0 volume%, alumina having a particle size of 0.4 μm is made into a composition of 60 volume%, these raw materials, methacrylic resin as a binder, toluene and ethanol as a solvent, and BPBG as a plasticizer are put into an alumina porcelain pot and dispersed. Disperse for 15 hours using alumina balls as media,
Obtain resistor paint.

As the insulator material, 90% by volume of alumina having a particle diameter of 0.4 μm, 10% by volume of mullite having a particle diameter of 0.4 μm, 3% by weight of magnesia having a particle diameter of 0.4 μm, and 0.3% by weight.
4 μm silica was made into a composition of 0.3% by weight, and, like the resistor material, these raw materials, methacrylic resin as a binder, toluene and ethanol as a solvent, and BPBG as a plasticizer were put into an alumina porcelain pot and dispersed. Disperse for 15 hours using alumina balls as media,
Obtain insulation paint.

(2) Manufacture of sheet The resistor paint and the insulator paint produced in the above process were adjusted on a polyethylene film by adjusting the height of a doctor blade so that the thickness after drying was 35 μm with a sheet coater. Then, an insulator paint film having a width of 80 mm is formed to obtain a resistor sheet and an insulator sheet. The formed resistor and insulator sheet are each cut into a length of 100 mm according to the stack size at the time of manufacturing a laminate.

(3) Production of Laminate A thick film layer was formed in the same manner as in Example 2, and after the predetermined lamination was completed, the laminate was placed in a pressing mold and subjected to 1.5 kg / cm ^2.
Is applied for 300 seconds. Next, the laminate is cut at a pitch of 4.8 mm to obtain a laminate having a length of 50 mm and a thickness of 3 mm.

(4) Production of Sintered Body The cut laminate was placed in a nitrogen gas at 600 ° C. for 2 hours.
Then, firing is performed at 1,650 ° C. for 2 hours in argon gas. Further, by the HIP method,
1600 atm for 2 hours in argon gas
After sintering at 1 ° C., a surface oxidation treatment is performed at 1,400 ° C. for 1 hour in air. After the oxidation treatment, the terminal connection is sandblasted.

(5) Assembly / Processing A palladium catalyst was printed on the terminal connection part, dried and then heat-treated, followed by nickel electroless plating. After washing and drying, the element in which the lead member is joined with silver wax is inserted into an alumina tube,
It is filled with ceramic cement and heat-cured after drying.

Tables 5 and 6 show the measurement results of the electrical characteristics of the temperature sensor element sample thus obtained. Table 5 shows the change in the resistance value of Sample G of this example with temperature.
Table 6 shows the response speed of the resistance value measured in the nitrite melt at 400 ° C.

[0085]

[Table 5]

[0086]

[Table 6] FIG. 11 is a graph showing the rate of change of the resistance value in Table 5 with temperature, and FIG. 12 is a graph showing the response speed of the rate of change of the resistance value in Table 6.

According to Table 5 and the corresponding graph of FIG. 11, the resistance type temperature sensor of the second embodiment using tungsten silicide as the resistor material shows that the resistance value changes sufficiently with temperature change. Is evident.

Further, according to Table 6 and the corresponding graph of FIG. 12, the temperature sensor of Example 3 using tungsten silicide as the resistor material has a sufficient response speed to change the resistance to the expected value. It is clear that there is.

[Embodiment 4] As described above, the resistance type temperature sensor using molybdenum, tungsten, titanium and tantalum silicide as a resistance material can be used even at a high temperature of around 1,300 ° C. Temperature is 1.0
For applications in a relatively low temperature range of around 00 ° C., most other metal silicides can be used, and in particular, elements IVA, VA, VIA, V
Group III metal silicides are highly available. Above all, silicides of chromium (Cr), iron (Fe), and cobalt (Co) are desirable materials in comprehensive consideration of material cost and ease of production.

These metal silicides, chromium silicide (C
rSi ₂ ), iron silicide (FeSi ₂ ), cobalt silicide (Co
Si ₂ ) has lower heat resistance than silicides of refractory metals such as molybdenum silicide and tungsten silicide, but is sufficiently used when used in a relatively low temperature range of about 1,000 ° C. It is possible. Therefore, in place of molybdenum silicide, tungsten silicide, titanium silicide, and tantalum silicide, which are high in heat resistance but more expensive, inexpensive chromium silicide, iron silicide, and cobalt silicide are used as the resistor material. The resistance type temperature sensor will be described.

(1) Preparation of Material The composition of the resistive material was as follows for each of Sample H, Sample I and Sample J. Sample H: 40% by volume of chromium silicide having a particle size of 2.5 μm, and alumina having a particle size of 0.4 μm. 60% by volume, Sample I: 40% by volume of 3.4 μm particle size iron silicide, 60% by volume of 0.4 μm particle size alumina, Sample J: 40% by volume of 2 μm particle size cobalt silicide, 60% by volume alumina %, And the insulating material has the same composition as that of the first embodiment.

(2) Production of Laminated Body After forming a thick film layer and completing the prescribed lamination in the same manner as in Example 2, the laminated body was placed in a pressing mold, and a pressure of 1.5 kg / cm ² was applied for 300 minutes. Add for seconds. Next, the laminate is cut at a pitch of 4.8 mm to obtain a laminate sample having a length of 50 mm and a thickness of 3 mm.

(3) Production of Sintered Body The cut laminate was placed in a nitrogen gas at 600 ° C. for 2 hours.
After removing the binder in step 1,
Bake at 250 ° C. In addition, 1,50 by HIP method
After firing at 1,200 ° C. for 2 hours in argon gas at 0 atm, a surface oxidation treatment is performed in air at 1,100 ° C. for 1 hour. After the oxidation treatment, the terminal connection is sandblasted.

(4) Assembly and Processing of Element A palladium catalyst was printed on the terminal connection portion, and after drying and heat treatment, nickel electroless plating was performed. After washing and drying, the element in which the lead member is joined with silver wax is inserted into an alumina tube,
It is filled with ceramic cement and heat-cured after drying.

The results of measuring the electrical characteristics of the temperature sensor element manufactured as described above are shown in Tables 7 and 8 below, in which the sample mainly composed of chromium silicide is sample H, the sample mainly composed of iron silicide is sample I, and the sample mainly composed of cobalt silicide is shown. Is shown as Sample J. Tables 7 and 8 show the measurement results of the electrical characteristics of the temperature sensor element sample thus obtained. Table 7 shows the change in the resistance of the sample of this example with temperature, and Table 8 shows the response speed of the resistance measured in a nitrite melt at 400 ° C.

[0096]

[Table 7]

[0097]

[Table 8]

In these tables, H is for a sample mainly composed of chromium silicide, I is for a sample mainly composed of iron silicide, and as Sample I, J is a specimen mainly composed of cobalt silicide. . FIG. 13 shows Table 7.
FIG. 14 is a graph showing the response speed of the change rate of the resistance value in Table 8 in a graph.

According to Table 7 and the corresponding graph in FIG. 13, it is clear that the resistance value of the resistance type temperature sensor using these resistance materials changes sufficiently with temperature.

According to Table 8 and the corresponding graph of FIG. 14, it is clear that the resistance value of the resistance type temperature sensor using these resistance materials has changed to the expected value with a sufficient response speed. .

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a laminated structure of a resistance temperature sensor element according to a first embodiment.

FIG. 2 is a pattern of a thick film used in the first embodiment.

FIG. 3 is an explanatory view of a manufacturing process of a thick film layer and a laminate.

FIG. 4 is another laminated structure diagram of the resistance-type temperature sensor element according to the first embodiment.

FIG. 5 is an explanatory view for assembling and processing the resistance type temperature sensor element of the first embodiment.

FIG. 6 is a graph showing the rate of change of the resistance value with temperature in Example 1.

FIG. 7 is a graph showing the response speed of the rate of change of the resistance value in Example 1.

FIG. 8 is a schematic structural diagram, a laminated structural diagram, and a pattern of a new thick film body of the resistance temperature sensor element body of the second embodiment.

FIG. 9 is a graph showing the rate of change of the resistance value with temperature in Example 2.

FIG. 10 is a graph showing the response speed of the rate of change of the resistance value in Example 2.

FIG. 11 is a graph showing a rate of change in resistance value with temperature in Example 3.

FIG. 12 is a graph showing the response speed of the rate of change of the resistance value in Example 3.

FIG. 13 is a graph showing the rate of change of the resistance value with temperature in Example 4.

FIG. 14 is a graph showing the response speed of the rate of change of the resistance value in Example 4.

[Explanation of symbols]

1, 2 connection terminal 3 insulating part 4, 5 conductive part 6 temperature sensing part 7, 8 protective layer 9, 10, 11, 12, 13, 14, 15, 16 resistor 21, 27, 32 polyethylene film 22, 25, 26 Resistor Thick Film 23, 24, 29, 30 Cut 28, 31 Insulator Thick Film 33 Thick Film Layer 35, 36 Lead Member 37, 38 Connection 39 Alumina Tube 40 Ceramic Cement 41, 42 Opening 43 Temperature Sensing Part 44 , 45 opening

Claims (5)

[Claims] 1. A resistance type in which a conductor material containing a metal silicide such as MoSi ₂ and an insulating base mainly composed of alumina are alternately laminated, and at least a part of the laminated structure constitutes a resistance circuit. Temperature sensor. 2. The material of the temperature sensing portion is 30 to 100% by volume of a metal silicide such as MoSi ₂ , and the remainder is an insulator containing alumina as a main component, and the insulator is 15% by volume or less of mullite. And 5% by weight or less of MgO, and the material of the lead portion is 50 to 100% by volume of a metal silicide such as MoSi ₂ ,
The remainder is an insulator containing alumina as a main component, and the insulator contains 15% by volume or less of mullite and 5% by weight or less of MgO, and the material of the insulating base is mainly alumina and 15% by volume or less of mullite. 5% by weight or less of MgO, SiO
_2. The resistance type temperature sensor according to claim 1, wherein said resistance type temperature sensor has a laminated structure containing 0.5% by weight or less. 3. A shape in which the thickness of the periphery of the temperature sensing portion is smaller than the thickness of the temperature sensor body, that is, at least one of the upper and lower outer portions of the laminated structure including the temperature sensing portion is cut off in the vicinity of at least one of the temperature sensing portions. 3. The resistance type temperature sensor according to claim 1, wherein the resistance type temperature sensor has a bent shape. 4. At least one of the outer upper and lower portions of the laminated structure including the temperature-sensitive portion is a laminated structure of at least one layer of a lead portion material or the same material as the temperature-sensitive portion material and an insulating base material. The resistance type temperature sensor according to claim 1, 2 or 3. 5. An at least one layer mainly composed of alumina or SiO ₂ on the outside of the element body including at least the temperature-sensitive part, excluding a part for electrically connecting the lead part to the outside. The resistance type temperature sensor according to claim 1, wherein the resistance type temperature sensor is covered with: