Temperature sensor and device equipped with temperature sensor

Abstract

Provided are: a temperature sensor with which a change in the characteristics of a temperature-sensitive element can be suppressed to ensure reliability; and a device equipped with this temperature sensor.　The present invention is characterized by comprising: a sensor element provided with a pair of leads (4) that are connected to a temperature-sensitive element (3); a protective case (2) that accommodates the sensor element; a filler (8) that fills a space between the protective case (2) and the sensor element inside the protective case (2); an electric wire (9) that is electrically connected to the leads (4) and that is led out to the outside of the protective case (2); a sealing material (6) that is composed of an electrical insulator which covers from the temperature-sensitive element (3) to a prescribed position of the pair of leads (4); and a dip resin (7) that is composed of an electrical insulator and covers from the sealing material (6) to a prescribed position of the pair of leads (4) and the electric wire (9). The present invention is also characterized in that the linear expansion coefficients of the sealing material (6), the dip resin (7), the temperature-sensitive element (3), and the leads (4) are set so that at least the dip resin (7) and the leads (4) do not separate from each other in a temperature cycle of liquid nitrogen and of boiling water.

Description

Temperature sensor and device equipped with temperature sensor

[0001] The present invention relates to a temperature sensor with good durability that can be used in a temperature range from extremely low temperatures to high temperatures, and to an apparatus equipped with a temperature sensor.

[0002] For example, thermistor temperature sensors using a temperature-sensitive sintered body as a temperature-sensitive element are used to detect the temperatures of home appliances such as air conditioners, refrigerators, and water heaters, as well as medical equipment and in-vehicle equipment such as automobiles. Such temperature sensors are required to be durable enough to withstand extremely low and high temperatures because they are used in harsh temperature environments where the temperature of the environment in which they are used is constantly changing.

[0003] To address this issue, temperature sensors have been proposed that offer improved heat cycle resistance, water resistance, and thermal response. Specifically, these sensors have a bottomed, pipe-shaped protective case with lead wires connected via electrodes on the surface of a temperature-sensitive sintered body, and a filler (filled resin) is placed around the temperature-sensitive sintered body inside the protective case. This configuration prevents the filler resin from peeling off from the protective case during heat cycles and escaping with the temperature-sensitive sintered body. These temperature sensors also suffer from the problem of moisture seeping into the area around the temperature-sensitive sintered body due to low-temperature condensation, causing malfunctions.

[0004] In recent years, air conditioners and other air conditioning equipment are being required to be able to operate in temperatures ranging from extremely low temperatures of -80°C to high temperatures of 150°C. Temperature sensors for cooking appliances are also required to measure temperatures above 200°C. Furthermore, in the medical field, there is a demand for the storage of genes in extremely low temperatures such as liquid nitrogen.

[0005] Patent No. 6360273 Patent No. 6405074 Patent No. 6987305

[0006] However, in the above-mentioned conventional temperature sensors, although attention has been paid to preventing the problem of the temperature-sensitive sintered body escaping from the protective case together with the filled resin, no attention has been paid to the characteristics of the temperature-sensitive sintered body in response to heat cycles over a wide temperature range from extremely low temperatures to high temperatures, i.e., changes in resistance value.

[0007] In particular, air conditioners and freezers have a wide temperature range, from extremely low temperatures of -80°C or less to abnormally high temperatures where the temperature of the outdoor unit's protruding pipe reaches 150°C. However, there is no wide-range temperature sensor that can cover all of these temperature ranges with a single temperature sensor.

[0008] Furthermore, temperature sensors used in extremely humid atmospheres allow moisture to penetrate even through minute gaps. If this moisture reaches the pair of leads connected to the temperature-sensing element, it can cause an electrical short circuit. Because temperature sensors are subject to repeated temperature fluctuations, repeated expansion and contraction of the leads and the components surrounding the leads can easily create gaps around the leads. This increases the risk of moisture penetrating the leads in humid atmospheres.

[0009] An embodiment of the present invention aims to provide a temperature sensor and a device equipped with this temperature sensor that not only prevents the problem of the temperature sensor element escaping from the protective case along with the filling resin, but also suppresses changes in the characteristics of the temperature sensor element to ensure reliability.

[0010] Another object of the present invention is to provide a temperature sensor that can prevent short circuits even when used in a humid atmosphere by preventing gaps from occurring around the conductors (leads) or minimizing any gaps that may occur.

[0011] A temperature sensor according to an embodiment of the present invention comprises a sensor element including a thermosensitive element and a pair of leads electrically connected to the thermosensitive element, a protective case that houses the sensor element, a filler that fills the gap between the protective case and the sensor element inside the protective case, electric wires that are electrically connected to the leads and extend to the outside of the protective case, a sealing material made of an electrical insulator that covers from the thermosensitive element to predetermined positions on the pair of leads, and a dipping resin made of an electrical insulator that covers from the sealing material to predetermined positions on the pair of leads and the electric wires, wherein the linear expansion coefficients of the sealing material, the dipping resin, the thermosensitive element, and the leads are set so that at least the dipping resin and the leads do not peel off during temperature cycles of liquid nitrogen and boiling water. A device equipped with a temperature sensor according to an embodiment of the present invention is characterized by being equipped with a temperature sensor according to an embodiment of the present invention.

[0012] The devices equipped with a temperature sensor include various devices equipped with a temperature sensor for detecting various temperatures, such as home appliances such as air conditioners, refrigerators, and water heaters, medical equipment, and in-vehicle equipment such as automobiles, which use a thermistor as a temperature sensor. However, there is no particular limitation on the devices to which the temperature sensor can be applied.

[0013] According to an embodiment of the present invention, it is possible to provide a temperature sensor and a device equipped with this temperature sensor, which can prevent the problem of the temperature sensor escaping from the protective case along with the filling resin, and which can prevent moisture from entering even in harsh environments such as extremely low temperature and high temperature regions, thereby suppressing changes in the characteristics of the temperature sensor and ensuring reliability.

[0014] Furthermore, it is possible to provide a temperature sensor and an apparatus equipped with the temperature sensor that can be used in a wide temperature range from extremely low temperatures to high temperatures, has good durability, and has a wide range of applications.

[0015] 1 is a plan cross-sectional view of a temperature sensor according to an embodiment of the present invention; 2 is a front cross-sectional view of the same temperature sensor; 3 is a table showing the linear expansion coefficients of each component of the same temperature sensor; 4 is a front cross-sectional view of a temperature sensor according to another embodiment of the present invention; 5 is a plan cross-sectional view of a temperature sensor according to another embodiment of the present invention; 6 is a front cross-sectional view of a temperature sensor of a comparative example; 7 is a table showing the results of a comparative evaluation in which 20,000 temperature cycles were performed under test conditions of immersion in water at 5°C for 1 minute to immersion in water at 85°C for 1 minute; 8 is a table showing the results of a comparative evaluation in which 10 temperature cycles were performed under test conditions of immersion in liquid nitrogen at -196°C for 1 minute to immersion in silicone oil at 206°C for 1 minute; 9 is a table showing the results of a comparative evaluation in which 20 temperature cycles were performed under test conditions of immersion in liquid nitrogen at -196°C for 1 minute to immersion in boiling water at 100°C for 1 minute; 10 is a table showing the results of a comparative evaluation in which 10,000 temperature cycles were performed under test conditions of immersion in silicone oil at -30°C for 10 minutes to immersion in silicone oil at 150°C for 10 minutes. The test conditions were a boiling current test, and the table shows the comparative evaluation results after 1,340 hours in boiling water at 100°C.

[0016] A temperature sensor according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 5. FIGS. 1 and 2 are plan and front cross-sectional views of the temperature sensor, FIG. 3 is a table showing the linear expansion coefficients of each component, and FIGS. 4 and 5 are front and front cross-sectional views of a temperature sensor according to another embodiment of the present invention. In each drawing, identical or corresponding parts are designated by the same reference numerals, and redundant explanations will be omitted. In addition, the scale of each component has been appropriately changed for the purpose of explanation so that each component can be recognized.

[0017] As shown in Figures 1 and 2, the temperature sensor 1 is a temperature-sensitive resistor with temperature-sensing properties, and includes a protective case 2, a temperature sensor 3 of a temperature-sensing element, leads 4, a sealing material 6, a dipping resin 7, a filling resin 8 as a filler, and an electric wire 9.

[0018] The temperature sensor 3 is preferably a temperature-sensitive sintered body, but is not limited to a temperature-sensitive sintered body and may be composed of a platinum resistor, a thin film thermistor, or a thermocouple, and is not particularly limited to a specific one. In the case of a platinum resistor or a thin film thermistor formed on an insulating substrate, it is possible to make the thermal time constant extremely fast by using an ultra-thin glass substrate as the substrate.

[0019] The sensor element is made up of the temperature sensor 3 and leads 4 of the temperature sensor element. The temperature sensor 3 and leads 4 are connected and sealed with a sealing material 6. The leads 4 are electrically connected to each core wire 91 of the electric wire 9. Furthermore, the temperature sensor 3 is placed in a protective case 2, insulated with a dipping resin 7, and surrounded by a filling resin 8.

[0020] The protective case 2 is made of resin or metal and has a pipe shape with one end open and one end closed, and is formed in a cylindrical or square tube shape. A cylindrical case with an outer diameter of 6 to 8 mm and a length of 20 to 30 mm is generally selected.

[0021] If the protective case 2 is made of resin, it is preferable to use a highly heat-resistant resin such as PPS (polyphenylene sulfide), liquid crystal polymer, PAI (polyamide-imide), or PEI (polyether-imide), which can ensure heat resistance up to 200°C. If the protective case 2 is made of metal, copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), or an alloy containing at least one of these metals can be used.

[0022] Furthermore, when the protective case 2 is made of resin, it is desirable to plate the resin protective case 2 with the above-mentioned metal, i.e., copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), or an alloy containing at least one of these metals. Furthermore, by plating the resin protective case 2 with a metal, the water resistance and oil resistance of the temperature sensor 1 can be improved.

[0023] When the temperature sensor 3 is a temperature-sensitive sintered body, it is a thermistor formed in a substantially rectangular parallelepiped shape and is composed of two or more elements selected from transition metal elements such as manganese (Mn), nickel (Ni), cobalt (Co), iron (Fe), yttrium (Y), chromium (Cr), copper (Cu), and zinc (Zn), and is composed of an oxide thermistor material containing a composite metal oxide having a crystalline structure as its main component. Subcomponents may also be contained to improve characteristics, etc. The composition and content of the main component and subcomponents can be determined appropriately depending on the desired characteristics.

[0024] The temperature sensor 3 is made of silicon carbide (SiC), silicon nitride (Si ３ N ４ The thermistor may be made of silicon (Si) ceramics such as silicon dioxide, silicon nitride, silicon nitride, silicon carbide, silicon nitride ...

[0025] Therefore, the temperature sensor 3 can be formed of a compound semiconductor of metal oxide or metal nitride. Note that the temperature sensor 3 may have a low B constant characteristic so that it can be used over a wide temperature range. An electrode layer 31 is formed on the surface of the temperature sensor 3.

[0026] The leads 4 are a pair of conductive lead wires that are electrically connected by welding, soldering, or the like to an electrode layer 31 made of gold (Au), chromium (Cr), copper (Cu), platinum (Pt), or the like formed on the surface of the temperature sensor 3, and are adapted to be led out from an opening on one end of the protective case 2. The leads 4 are electrically connected by soldering or the like to each core wire 91 of the electric wire 9, and are insulated by an insulating coating 92. The electrode layer 31 and the like that make up the sensor element do not contain silver (Ag) in order to avoid migration.

[0027] Dumet wire or CP wire is preferably used as the material for the lead 4. The material for the lead 4 is characterized by being copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), or an alloy containing at least one of these, or a copper-plated wire, copper-tin-plated wire, or copper-clad wire having any of these as a core material.

[0028] The leads 4 can be in any form, such as a solid wire or a rectangular wire. The length of the leads 4 is typically 5 to 15 mm, and is selected taking into consideration the size of the protective case 2. The pair of leads 4 are formed with bent portions 41 at their tips so that they are aligned parallel to the pitch of the core wires 91 of the electric wires 9. Specifically, a gap of 1 mm or more is maintained. The connection portions to the electrode layer 31 at the tips of the leads 4 are arranged and connected obliquely to the surface of the temperature sensor 3.

[0029] Furthermore, the cross-sectional area of ​​the lead 4 is 0.097 mm ２ The results are as follows: It is believed that the cross-sectional area of ​​the lead 4 has a large effect on the change in resistance of the temperature sensor 3. As the cross-sectional area of ​​the lead 4 increases, the change in resistance tends to increase.

[0030] Therefore, the cross-sectional area of ​​the lead 4 is small, 0.097 mm ２ It was found that if the lead 4 is thicker and has a larger cross-sectional area, it is possible to keep the change in resistance small. This is presumably because a larger force is applied to the temperature sensor 3 when the lead 4 is thicker and has a larger cross-sectional area. In addition, when the lead 4 is thinner and has a smaller cross-sectional area, less heat is dissipated from the lead 4, enabling accurate temperature detection. When multiple leads 4 are used, the cross-sectional area of ​​the lead 4 can be determined by the total cross-sectional area of ​​the multiple leads.

[0031] The sealing material 6 covers and protects the temperature sensor 3, and is made of an insulating resin such as an epoxy resin with a high heat resistance temperature. This effectively protects the temperature sensor 3 and other components even when used in a high-temperature environment. The sealing material 6 may also be an acid anhydride-based epoxy resin containing a filler.

[0032] Dipping resin 7 is provided around the temperature sensor 3, ensuring insulation between the leads 4 and the core wires 91 of the electrically connected electric wires 9. This dipping resin 7 is provided by dipping the temperature sensor 3 connected to the leads 4 into insulating resin. Here, the linear expansion coefficient of the dipping resin 7 will be described in detail. The linear expansion coefficient of the dipping resin 7 is set to 20×10 －６ This is a method to achieve a temperature of 1000K or less.

[0033] When the filling resin 8 is an epoxy resin, the linear expansion coefficient of the epoxy resin is 20×10 －６ / °C or less can be obtained relatively easily. In the case of the filling resin 8, unlike the dipping resin 7, thixotropy is not required, so by adding an appropriate amount of filler to the base resin, the linear expansion coefficient can be made to be 20 x 10 －６ / °C or less can be achieved.

[0034] It is generally known that epoxy resins are usually used by mixing two liquids, a base resin and a hardener. In the case of dipping resin 7, thixotropy is required, which means that the dipped resin does not drip. Currently, dipping resin 7 that requires thixotropy has a linear expansion coefficient of 20 x 10 －６ No epoxy resins below / °C have been found.

[0035] The inventors used a special compounding method to create a dip resin that requires thixotropy and has a linear expansion coefficient of 20 x 10 －６ / °C or less. Specifically, this is achieved by adding at least one resin composition to a non-thixotropic epoxy resin that is a blend of two components, a base resin and a curing agent, to impart thixotropy. Without using such a special blending method, the linear expansion coefficient of the thixotropic epoxy resin is 20 x 10 －６ It becomes difficult to obtain a dipped epoxy resin at a temperature of 0.1°C or lower.

[0036] The dipping resin 7 may be an acid anhydride epoxy resin containing a filler. In the case of such a dipping resin 7, the linear expansion coefficient of the dipping resin 7 is 20×10 －６Dip epoxy resin with a temperature of 0.1 W / m K or less can be obtained. By using a dip epoxy resin containing a filler, the thermal conductivity of the dip epoxy resin is improved, and the thermal time constant is shortened. While the thermal time constant of a conventional structure is 10 seconds, the thermal time constant of a dip epoxy resin containing a filler with good thermal conductivity is 5 seconds. Dip resin 7 containing a filler has a thermal conductivity of 0.6 W / m K or more.

[0037] Furthermore, conventional flexible epoxy resins have the problem of epoxy components leaching out of uncured resin due to moisture such as humidity, but the dip epoxy resin of this embodiment does not have flexibility and does not have the problem of epoxy components leaching out.

[0038] The filling resin 8, which is a filler, is placed inside the protective case 2 and fills the area around the temperature sensor 3. Specifically, the filling resin 8 is an acid anhydride epoxy resin, and is placed around the temperature sensor 3, including the sealing material 5 that covers the temperature sensor 3 and the connection side of the leads 4 to the temperature sensor 3. The filling resin 8 may contain fillers such as ceramic, metal, and carbon that have good thermal conductivity.

[0039] In the temperature sensor 1 described above, the linear expansion coefficients of the various components are shown in FIG. 3. The linear expansion coefficients of the components, including the dipped resin 7, are 20×10 －６ The temperature sensor 3, which is a temperature sensing element, the leads 4, the sealing material 6, the dipping resin 7, and the protective case 2 are adjusted and set to a linear expansion coefficient of 7.5 to 19.5 × 10 －６ / °C, and specifically, 20 × 10 －６ It is adjusted and set to below / ℃.

[0040] Figure 4 shows a temperature sensor according to another embodiment of the present invention. Fig. 4 shows a cross-sectional front view. The temperature sensor 1 of this embodiment has the same basic configuration as the previously described embodiment. The sealing material 6 that covers and protects the temperature sensor 3, which is a temperature-sensing element, is made of glass, such as crystallized glass. This effectively protects the temperature sensor 3 and other components even when the temperature sensor 1 is used in a high-temperature environment. The pair of leads 4 are also formed with bent portions 41 that narrow the width at their tips to match the pitch of the core wires 91 of the electric wire 9, maintaining a gap of 1 mm or more.

[0041] FIG. 5 is a planar cross-sectional view of a temperature sensor, showing a case in which the temperature sensor of the temperature sensor element is a thin-film thermistor 3a. The thin-film thermistor 3a is formed by sputtering a thin film of a thermistor made of an oxide semiconductor with a negative temperature coefficient on an insulating inorganic substrate. The temperature sensor of the temperature sensor element may also be a platinum resistor, which is also formed by depositing a thin film on an insulating inorganic substrate. The insulating inorganic substrate is preferably an ultrathin glass substrate with a thickness of 100 μm or less. Next, the results of a comparative evaluation test of the temperature sensor 1 configured as described above and a comparative temperature sensor are described with reference to FIGS. 7 to 11.

[0042] First, the structure of a comparative example is shown in Figure 6. The temperature sensor 1' comprises a protective case 2', a temperature sensor 3', leads 4', an undercoat material 5, a sealing material 6', a dipping resin 7', a filling resin 8', and electric wires 9'. The protective case 2' is made of metal, the undercoat material 5 is silicone rubber, the sealing material 6' is made of glass, and the dipping resin 7' and the filling resin 8' are epoxy resins.

[0043] Figure 7 is a table showing the results of the comparative evaluation. The test conditions were to immerse the temperature sensor in water at 5°C for 1 minute and then immerse it in water at 85°C for 1 minute per cycle, apply 5V, and perform 20,000 temperature cycles. The comparative test items were appearance observation to observe deformation or damage to the protective case, and cross-sectional observation to observe the state of insulation resistance, resistance changes in the temperature sensor, and the occurrence of gaps around the leads. The test conditions were general waterproofing tests, and no difference was found in this evaluation between this embodiment and the comparative example.

[0044] Figure 8 is a table showing the results of the comparative evaluation. The test conditions were that the temperature sensor was immersed in liquid nitrogen at -196°C for 1 minute and silicone oil at 206°C for 1 minute, and 10 temperature cycles were carried out.

[0045] In a temperature cycle test in liquid from an extremely low temperature of -196°C to 206°C, deformation and damage were observed in the protective case 2' of the comparative example, and the appearance inspection was NG, and a gap occurred between the lead 4' (including the silicone rubber undercoat material 5) and the dipping resin 7', and in an insulation test in water, water penetrated and insulation resistance could not be secured, resulting in NG. In contrast, it was confirmed that there were no abnormalities in this embodiment.

[0046] Figure 9 is a table showing the results of the comparative evaluation. The test conditions were to immerse the temperature sensor in liquid nitrogen at -196°C for 1 minute, followed by boiling water at 100°C (100°C water (boiling water)) for 1 minute per cycle, and to carry out 20 temperature cycles.

[0047] 8, in the comparative example, deformation and damage were observed in the protective case 2', so the appearance observation was NG, a gap occurred between the lead 4' (including the silicone rubber undercoat material 5) and the dipping resin 7', so the cross-section observation was NG, and in the underwater insulation test, water penetrated and the insulation resistance could not be secured, so the insulation resistance was NG. In contrast, in this embodiment, it was confirmed that there were no abnormalities.

[0048] Figure 10 is a table showing the results of the comparative evaluation. The test conditions were as follows: the temperature sensor was immersed in silicon oil at -30°C for 10 minutes and silicon oil at 150°C for 10 minutes per cycle, and 5 V was applied, and 10,000 temperature cycles were performed.

[0049] In the comparative example, deformation and damage were observed in the protective case 2', resulting in an unacceptable appearance observation. Also, a gap occurred between the lead 4' (including the silicone rubber undercoat material 5) and the dipping resin 7', resulting in an unacceptable cross-sectional observation. An underwater insulation test revealed that water had penetrated the device, preventing insulation resistance, resulting in an unacceptable insulation resistance result. Furthermore, the resistance of the temperature-sensing element also changed. In contrast, no abnormalities were confirmed in this embodiment. The absence of gaps in the water intrusion path thus effectively prevents water from penetrating.

[0050] 11 is a table showing the results of the comparative evaluation. The test conditions were a boiling current test, in which the temperature sensor was immersed in boiling water at 100°C, 5 V was applied, and the evaluation was carried out after 1340 hours had passed.

[0051] In a boiling current test at 100° C., it was confirmed that the lead 4′ in the comparative example was broken at the portion where the silicone rubber undercoat material 5 was present, whereas no abnormality was observed in this embodiment.

[0052] As described above, in the comparative example, in order to improve weather resistance in humid atmospheres, the temperature sensor 3' and its leads 4' are insulated with a dip resin 7' such as elastic silicone rubber or epoxy resin to prevent moisture penetration. However, in extremely low temperatures, the elasticity of silicone rubber or epoxy resin deteriorates and they become hard, causing gaps between the leads 4' and peeling, making it impossible to prevent moisture penetration. Furthermore, because silicone rubber has a high linear expansion coefficient, it places a load on the leads 4', which may result in breakage.

[0053] According to this embodiment, it is possible to obtain a temperature sensor 1 that can be used in a wide range from the extremely low temperature of -196°C to the high temperature range of 206°C, and it is possible to prevent the problem of the temperature sensor 3 escaping from the protective case 2 together with the filling resin 6, and it is possible to provide a temperature sensor 1 that can prevent the intrusion of moisture even in harsh environments such as the extremely low temperature range and the high temperature range, suppress changes in the characteristics of the temperature sensor 3, and ensure reliability.

[0054] 9, in this embodiment, the linear expansion coefficients of the sealing material 4, dipping resin 7, thermosensitive element, and leads 7 are set so that at least the dipping resin 7 and the leads 4 do not peel off during a temperature cycle of liquid nitrogen and boiling water. Specifically, the linear expansion coefficients of the temperature sensor 3, which is the thermosensitive element, the leads 4, the sealing material 6, the dipping resin 7, and the protective case 2 are set to 20×10 －６ It is adjusted and set to below / ℃.

[0055] The temperature sensor 1 can be applied to various temperature sensors, such as thermistors, which use a temperature sensor as a temperature sensing element to detect the temperature of home appliances such as air conditioners, refrigerators, and water heaters, medical equipment, and in-vehicle equipment such as automobiles. There are no particular limitations on the devices to which the temperature sensor 1 can be applied.

[0056] The present invention is not limited to the configuration of the above-described embodiment, and various modifications are possible within the scope of the invention. Furthermore, the above-described embodiment is presented as an example and is not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims.

[0057] REFERENCE SIGNS LIST 1 Temperature sensor 2 Protective case 3 Temperature sensor (thermosensitive sintered body) 3a Temperature sensor (thin film thermistor) 31 Electrode layer 4 Lead 41 Bent portion 5 Undercoat material 6 Sealing material 7 Dipping resin 8 Filling resin (filling body) 9 Electric wire 91 Core wire 92 Insulating coating

Claims

1. A sensor element comprising a temperature sensing element and a pair of leads electrically connected to the temperature sensing element, A protective case housing the aforementioned sensor element, A filler that fills the space between the protective case and the sensor element inside the protective case, A wire electrically connected to the lead and led out of the protective case, A sealing material consisting of an electrical insulator covering the area from the temperature sensing element to a predetermined position of the pair of leads, A dip resin consisting of an electrical insulator that covers from the sealing material to a predetermined position of the pair of leads and the electric wire, Equipped with, A temperature sensor characterized in that the coefficient of linear expansion of the protective case, the sealing material, the dip resin, the temperature sensing element, and the lead is 20 × 10⁻⁶ / °C or less.

2. The temperature sensor according to claim 1, characterized in that the dip resin is made of a thixotropic resin and is not flexible.

3. The temperature sensor according to claim 2, characterized in that the dip resin is composed of a non-thixotropic epoxy resin, which is a two-component mixture of a main agent and a curing agent, to which at least one resin composition is added so as to impart thixotropy.

4. The temperature sensor according to claim 2, characterized in that the dip resin is made of an acid anhydride-based epoxy resin containing a filler, and has a thermal conductivity of 0.6 W / m·K or more.

5. The temperature sensor according to one of claims 1 to 4, characterized in that the cross-sectional area of ​​the lead is 0.097 mm² or less.

6. The temperature sensor according to one of claims 1 to 4, characterized in that the temperature sensing element is a temperature-sensing sintered body and is a compound semiconductor of a metal oxide or metal nitride.

7. The temperature sensor according to one of claims 1 to 4, characterized in that the temperature sensing element is a platinum resistor or a thin-film thermistor formed on an insulating substrate of an inorganic material.

8. The temperature sensor according to one of claims 1 to 4, characterized in that the temperature sensing element is a platinum resistor or a thin-film thermistor formed on an ultrathin glass substrate.

9. The temperature sensor according to one of claims 1 to 4, characterized in that the lead is formed to match the pitch of the core wires of the electric wire.

10. The temperature sensor according to one of claims 1 to 4, characterized in that the sealing material is glass or resin.

11. The temperature sensor according to one of claims 1 to 4, characterized in that the filler and the sealing material are an acid anhydride-based epoxy resin containing a filler.

12. The temperature sensor according to one of claims 1 to 4, characterized in that the material of the protective case is a resin, and is PPS (polyphenylene sulfide), liquid crystal polymer, PAI (polyamide-imide), or PEI (polyetherimide).

13. The temperature sensor according to one of claims 1 to 4, characterized in that the material of the protective case is copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), or an alloy containing at least one of these.

14. The temperature sensor according to one of claims 1 to 4, characterized in that the material of the lead is copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), or an alloy containing at least one of these.

15. The temperature sensor according to one of claims 1 to 4, characterized in that the material of the lead is copper (Cu), iron (Fe), chromium (Cr), nickel (Ni), aluminum (Al), zinc (Zn), titanium (Ti), tin (Sn), or an alloy containing at least one of these, and a copper-plated wire, copper-tin plated wire, or copper-clad wire using these as a core material.

16. An apparatus equipped with a temperature sensor, characterized in that it is provided with a temperature sensor as described in one of claims 1 to 4.