JP2018004309A - Temperature sensing element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temperature sensing element in which connection between an electrode and leads on an insulating substrate is stably maintained over a long period of time and which has high reliability and long lifetime.SOLUTION: A temperature sensing element 10 includes: rectangular plate-like insulating substrate 1; resistance wiring 2 provided in the insulating substrate 1; a first electrode 3a and a second electrode 3b provided on one main surface of the insulating substrate 1; and leads 4 connected to each of the first electrode 3a and the second electrode 3b. The temperature sensing element has a recess 4a and a protruding part 4b connecting to the inner wall of the recess 4a on the surface of the lead 4.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a temperature measuring body in which a resistance wiring and a lead are provided on an insulating base made of a ceramic sintered body.

  As a temperature sensing element for temperature detection used in an exhaust gas sensor or the like, one utilizing a change in electrical resistance of a metal material with temperature is known. For example, a temperature measuring body having an insulating base made of a ceramic sintered body such as an aluminum oxide sintered body, a resistance wiring including an electrode provided on the insulating base, and a lead is used.

JP-A-11-121214

  However, in the case of the above-mentioned temperature measuring element, there is a possibility of causing the following problems. That is, for example, when measuring the temperature of exhaust gas from a device having a combustion part such as an internal combustion engine, a gas turbine, a boiler, or the like, stress due to vibration of the device or stress during handling of the temperature measuring element is applied to the lead, and the lead and electrode The connection strength between the lead and the electrode is reduced, the connection between the lead and the electrode is reduced, and the resistance at the connection between the lead and the electrode may be increased.

  A temperature sensing element according to one aspect of the present invention includes an insulating substrate, a resistance wiring provided on the insulating substrate, a first electrode and a second electrode provided on one main surface of the insulating substrate, and the first electrode. An electrode and a lead connected to each of the second electrodes, and a surface of the lead having a recess and a protrusion connected to the inner wall of the recess.

  A temperature sensing element according to one aspect of the present invention includes an insulating base, a resistance wiring provided on the insulating base, a first electrode and a second electrode provided on one main surface of the insulating base, a first electrode, and a first electrode. A lead connected to each of the two electrodes, and the lead surface has a recess and a protrusion connected to the inner wall of the recess, for example, combustion of an internal combustion engine, gas turbine, boiler, etc. Even if stress due to vibration of the device when measuring the temperature of exhaust gas from a device having a part, or stress during handling of a temperature measuring element is applied to the lead, the lead is caused by the concave part and the protruding part connected to the inner wall of the concave part. Stress is dispersed in the covering member to be coated, the connection strength between the lead and the electrode is difficult to decrease, and the connection portion between the lead and the electrode is difficult to be reduced. It is possible to suppress the resistance of the body is changed. As a result, the temperature sensing element can have high temperature change detection accuracy.

(A) is a perspective view which shows the temperature sensing element of this invention, (b) is a disassembled perspective view of (a). It is a top view except the covering member of the temperature sensing element shown to Fig.1 (a). It is a principal part enlarged plan view in the A section of the temperature sensing element shown in FIG. It is a longitudinal cross-sectional view in the AA line containing the coating | coated member of the temperature measuring body shown in FIG. It is a longitudinal cross-sectional view in the BB line containing the covering member of the temperature sensing element shown in FIG.

  A temperature sensor according to an embodiment of the present invention will be described with reference to the accompanying drawings. The distinction between the upper and lower sides in the following description is for convenience, and does not limit the upper and lower sides when a temperature measuring body or the like is actually used.

  As shown in FIGS. 1 to 5, an insulating base 1 in which a plurality of insulating layers 1 a (six layers are shown in the example shown in FIG. 1) are laminated, and an electrode 3 provided on the main surface of the insulating base 1, In addition, there is a resistance wiring 2 (may be provided as a single layer) provided in multiple layers in the thickness direction inside the insulating substrate 1. Temperature measurement is performed by utilizing the fact that the electrical resistance of the resistance wiring 2 changes according to the temperature. That is, the temperature of the environment where the temperature measuring body 10 is located is calculated from the measured value of the electrical resistance of the resistance wiring 2 and detected. The electrode 3 may be formed not only on the upper surface of the insulating substrate 1 but also on the lower surface. Alternatively, the insulating substrate 1 made of a single insulating layer may be used.

  The insulating base 1 has a flat plate shape such as a square plate, and is a base portion for providing the resistance wiring 2 by being electrically insulated. The insulating substrate 1 is made of, for example, a ceramic sintered body such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a glass ceramic sintered body, or a zirconia ceramic (zirconium oxide sintered body). Is formed. The insulating base 1 is formed by laminating a plurality of insulating layers 1a made of such a ceramic sintered body.

For example, if each insulating layer 1a is made of an aluminum oxide sintered body, the insulating base 1 can be manufactured by the following method. First, raw material powders such as silicon oxide (SiO ₂ ), magnesium oxide (MgO), and manganese oxide (Mn ₂ O ₃ ) are added to the aluminum oxide (Al ₂ O ₃ ) powder as a sintering aid, and further suitable A binder, a solvent and a plasticizer are added, and then the mixture is kneaded into a slurry. Thereafter, a ceramic green sheet is obtained by forming into a sheet shape by a conventionally known doctor blade method or calendar roll method, etc., and a suitable number of punching processes are performed on the ceramic green sheet, and a plurality of sheets are laminated as necessary (or A single sheet is prepared) and fired at a high temperature (about 1300 to 1600 ° C.). A plurality (or a single number) of ceramic green sheets each become the insulating layer 1a. The insulating substrate 1 includes glass having calcium (Ca), magnesium (Mg), or the like.

  The resistance wiring 2 is formed of platinum, which is a metal material whose electric resistance changes according to temperature, or a metal material containing platinum as a main component. In order to detect the change according to the temperature of the electric resistance of the metal material according to the temperature change, it is preferable that the absolute value of the electric resistance of the resistance wiring at the reference temperature (for example, a so-called normal temperature of about 25 ° C.) is larger.

  This is due to the following reason. That is, the change in the electrical resistance according to the temperature change of the resistance wiring 2 occurs at a constant ratio regardless of the magnitude (absolute value) of the electrical resistance at the reference temperature. That is, the larger the value of the electrical resistance at the reference temperature, the greater the absolute value of the change in electrical resistance associated with the temperature change. The larger the absolute value of this change in electrical resistance, the less susceptible to noise (electric resistance fluctuation due to factors other than temperature changes). Measurement is also easier. Therefore, it is preferable that the resistance wiring 2 has a larger electric resistance at the reference temperature. For this reason, a metal material such as platinum is linear (that is, the length of the section in which the electrical resistance is measured is long, and is effective in increasing the absolute value of the electrical resistance).

Components other than platinum in the metal material containing platinum as a main component are appropriately selected for the purpose of adjusting the temperature resistance coefficient (TCR) of the resistance wiring 2 and improving heat resistance. Selected. Examples of components other than platinum include metal materials of platinum group elements such as palladium, rhodium and iridium, and gold. For example, when the linearity of the change in electrical resistance with respect to the temperature change of the resistance wiring 2 is emphasized, it is preferable that the platinum content is large.

  The metal material mainly composed of platinum contains platinum in a proportion of about 80% by mass or more. Platinum and other components may form an alloy or may exist as crystal grains independent of each other. The resistance wiring 2 may contain an additive other than a metal component such as platinum or a metal material containing platinum as a main component. Examples of the additive include inorganic particles similar to those contained in the insulating substrate 1, such as aluminum oxide. The additive is added, for example, for matching the firing shrinkage rate between the resistance wiring 2 and the insulating layer 1a.

  The resistance wiring 2 is formed by, for example, applying a metal paste prepared by kneading platinum powder together with an organic solvent and a binder onto a main surface of a ceramic green sheet to be the insulating layer 1a in a predetermined pattern and simultaneously firing the paste. be able to.

  One end (first end) of the resistance wiring 2 is connected to the first end, second end and each resistance wiring 2 of each layer through a connection conductor 5 (through conductor) which will be described later. The electrical resistance between the side end (second end) is measured by, for example, an external electric circuit. This electrical resistance changes according to the temperature of the resistance wiring 2, and the temperature of the resistance wiring 2 changes according to the temperature (external temperature) of the environment where the temperature measuring element 10 or the like is located. That is, the external temperature is detected by detecting the electrical resistance between the first and second ends of the resistance wiring 2.

  The external temperature is, for example, the temperature of various combustion exhaust gases, and it may be necessary to detect a high temperature of about several hundred to 1,000 ° C. Since the stability at such a high temperature and the linearity of the electric resistance change according to the temperature are good, the resistance wiring 2 is made of platinum or a metal material containing platinum as a main component. For example, the temperature measuring element 10 having the electrode 3 is mounted (connected) to an external substrate (not shown) including the above-described resistance detection electric circuit (external electric circuit) to form a sensor device. The sensor device is mounted on a portion where a temperature measurement object exists (such as a gas flow path).

  In addition, if the resistance wiring 2 is exposed to the outside air, the electrical resistance is unnecessarily increased due to adhesion of foreign matter or destruction due to accidental collision with an external board or other components mounted on the external board. May change. In order to prevent this, the resistance wiring 2 is provided between the plurality of insulating layers 1a. In other words, the resistance wiring 2 is provided inside the insulating base 1 and is not exposed to the outside. In the case where the resistance wiring 2 is the insulating base 1 made of a single insulating layer, an insulating film or an insulating layer covering the resistance wiring 2 may be provided. The insulating film or insulating layer covering the resistance wiring 2 is formed of a ceramic sintered body similar to the insulating layer 1a.

  The electrodes 3 (first electrode 3a and second electrode 3b) provided on the temperature measuring body 10 are portions for connecting the resistance wiring 2 to an external substrate including an external electric circuit. The electrode 3 can be formed by the same method using, for example, the same metal material (platinum or the like) as the resistance wiring 2. The electrode 3 in the temperature measuring element 10 of the embodiment is a square pattern made of platinum. The electrode 3 may have other shapes.

  The electrode 3 is made of a metal material having high oxidation resistance at high temperatures, such as a platinum group metal or gold containing platinum, because it may be placed in a high temperature environment together with the temperature measuring element 10 as will be described later. Preferably there is.

The lead 4 has, for example, a cylindrical shape and is connected to the electrode 3, that is, the first electrode 3a and the second electrode 3b. The lead 4 is made of a metal material containing platinum, and may be made of pure platinum, like the resistance wiring 2 and the like. . The lead 4 is connected to the electrode 3 by, for example, joining means of ultrasonic joining using a horn including convex portions having a quadrangular pyramid shape arranged in a staggered manner in a plan view. 3 to 5 show the connecting portion (A portion) in which the lead 4 is connected to the second electrode 3b, the connecting portion in which the lead 4 is connected to the first electrode 3a has the same configuration. It has become.

  In this embodiment, the electrical connection between the electrode 3, the resistance wiring 2, and each resistance wiring 2 is performed by a connection conductor (so-called via conductor) 5 that penetrates the insulating layer 1 a in the thickness direction.

  The connection conductor 5 is formed of, for example, a conductor material (metal material) whose main component is the same metal material (platinum or the like) as the resistance wiring 2. Examples of such a metal material include platinum or a material mainly composed of platinum and added with an inorganic filler such as alumina. The inorganic filler is for, for example, matching the contraction rate and contraction behavior of the connection conductor 5 and the insulating base 1 when they are formed by simultaneous firing.

  The connecting conductor 5 is formed, for example, by filling a through hole provided in advance in a ceramic green sheet serving as the insulating layer 1a with the same platinum metal paste as that for forming the resistance wiring 2 and simultaneously firing. be able to. The through hole can be provided in the ceramic green sheet by a machining method such as mechanical drilling using a metal pin or laser beam drilling. In this case, the inorganic filler particles as described above may be added to the metal paste.

  As shown in FIGS. 1 to 5, the temperature measuring body 10 includes a rectangular plate-shaped insulating substrate 1, a resistance wiring 2 provided on the insulating substrate 1, and a first surface provided on one main surface of the insulating substrate 1. The electrode 3a and the second electrode 3b, and the lead 4 connected to each of the first electrode 3a and the second electrode 3b, and the protrusion 4 on the surface of the lead 4 is connected to the inner wall of the recess 4a and the recess 4a. 4b. By having such a configuration, for example, when measuring the temperature of exhaust gas from a device having a combustion part such as an internal combustion engine, a gas turbine, or a boiler, stress due to vibration of the device, or stress during handling of the temperature measuring element 10 Even if the lead 4 is added to the lead 4, the protruding portion 4 b is connected to the covering member 6 and the covering member 6 is inserted into the recessed portion 4 a by the protruding portion 4 b connected to the inner wall of the recessed portion 4 a and the lead 4 is covered. The stress is dispersed in the covering member 6 to be described later, the connection strength between the lead 4 and the electrode 3 is difficult to be reduced, and the connection portion between the lead 4 and the electrode 3 is difficult to be reduced. It is possible to suppress a change in resistance in the temperature sensing element 10 due to a defect. As a result, the temperature sensing element 10 can have high temperature change detection accuracy.

  For example, when the lead 4 is connected to the electrode 3, the recess 4 a on the surface of the lead 4 and the protrusion 4 b connected to the inner wall of the recess 4 a are formed by a horn that includes quadrangular pyramidal projections arranged in a staggered manner in a plan view. Provided by means of ultrasonic bonding.

  Moreover, the protrusion part 4b may protrude toward the outer side of the recessed part 4a, as shown in FIGS. By having such a configuration, for example, when measuring the temperature of exhaust gas from a device having a combustion part such as an internal combustion engine, a gas turbine, or a boiler, stress due to vibration of the device, or stress during handling of the temperature measuring element 10 Even if the lead 4 is added to the recess 4a and the inner wall of the recess 4a, the protrusion 4b protruding toward the outside of the recess 4a causes the protrusion 4b to become the covering member 6 and the covering member 6 to the recess 4a. It is configured to enter, and the stress is more dispersed in the covering member 6 described later, which covers the lead 4, the connection strength between the lead 4 and the electrode 3 is less likely to be lowered, and the connection portion between the lead 4 and the electrode 3 is smaller. Therefore, it is possible to further suppress a change in resistance in the temperature measuring element 10 due to a poor connection between the lead 4 and the electrode 3. As a result, the temperature sensing element 10 can have high temperature change detection accuracy.

  Further, in a plan view, the protrusion 4b may be provided so as to surround the recess as shown in FIG. By having such a configuration, for example, when measuring the temperature of exhaust gas from a device having a combustion part such as an internal combustion engine, a gas turbine, or a boiler, stress due to vibration of the device, or stress during handling of the temperature measuring element 10 However, even if it is added to the lead 4 in any plane direction, the protrusion 4b is connected to the inner surface of the recess 4a and the recess 4a, and the protrusion 4b provided so as to surround the recess 4a. Further, the covering member 6 is configured to enter the recess 4a, the stress is effectively dispersed in the covering member 6 to be described later, which covers the lead 4, and the connection strength between the lead 4 and the electrode 3 is not easily lowered. The connection portion with the electrode 3 is difficult to be reduced, and the resistance of the temperature measuring body 10 due to poor bonding between the lead 4 and the electrode 3 is effectively suppressed. be able to. As a result, the temperature sensing element 10 can have high temperature change detection accuracy.

  In plan view, the recess 4 a has a rectangular shape, and may be arranged inclined with respect to the longitudinal direction of the lead 4. By having such a configuration, for example, when measuring the temperature of exhaust gas from a device having a combustion part such as an internal combustion engine, a gas turbine, or a boiler, stress due to vibration of the device, or stress during handling of the temperature measuring element 10 However, even if it is added to the lead 4 with respect to the longitudinal direction of the lead 4, the protruding portion 4 b is connected to the inner wall of the recessed portion 4 a and the recessed portion 4 a and is inclined with respect to the longitudinal direction of the lead 4. 4b is covered with the covering member 6 and the covering member 6 enters the recess 4a, and the lead 4 is covered. The covering member 6 described later effectively distributes the stress, and the connection strength between the lead 4 and the electrode 3 is increased. It is difficult to decrease, the connection portion between the lead 4 and the electrode 3 is difficult to be reduced, and the resistance in the temperature measuring body 10 is changed due to poor bonding between the lead 4 and the electrode 3. It can suppress more effectively. As a result, the temperature sensing element 10 can have high temperature change detection accuracy.

  In plan view, the recesses 4a may be arranged in a staggered manner as shown in FIGS. By having such a configuration, for example, when measuring the temperature of exhaust gas from a device having a combustion part such as an internal combustion engine, a gas turbine, or a boiler, stress due to vibration of the device, or stress during handling of the temperature measuring element 10 However, even if it is added to the lead 4 in any plane direction, the protrusion 4b is formed on the covering member 6 by the recess 4a arranged in a staggered manner and the protrusion 4b connected to the inner wall of the recess 4a. 6 enters the recess 4a, and the stress is effectively dispersed by the covering member 6 to be described later, which covers the lead 4, and the connection strength between the lead 4 and the electrode 3 is not easily lowered. Therefore, it is difficult to reduce the connection portion of the lead wire 4 and the resistance of the temperature sensing element 10 due to poor bonding between the lead 4 and the electrode 3 can be more effectively suppressed. Yes. As a result, the temperature sensing element 10 can have high temperature change detection accuracy.

  In addition, the temperature measuring element 10 according to the embodiment of the present invention is made of a glass material, includes a recess 4a and a protrusion 4b, and covers a connecting member 6 that covers a connection portion of the lead 4 with the first electrode 3a and the second electrode 3b. have. By having such a configuration, the covering member 6 is firmly joined to the insulating base 1 and the like, for example, when measuring the temperature of exhaust gas from a device having a combustion part such as an internal combustion engine, a gas turbine, or a boiler. Even if stress due to device vibration or stress during handling of the temperature sensing element 10 is applied to the lead 4, the stress is effectively dispersed in the covering member 6, and the connection strength between the lead 4 and the electrode 3 is reduced. Therefore, it is difficult to reduce the connection portion between the lead 4 and the electrode 3, and it is possible to effectively suppress the resistance in the temperature measuring body 10 from being changed due to poor bonding between the lead 4 and the electrode 3. As a result, the temperature sensing element 10 can have high temperature change detection accuracy.

  The covering member 6 is made of a glass material such as barium silicate glass or borosilicate glass, and can be manufactured by the following method.

  First, a slurry prepared by adding and mixing an appropriate organic binder and a solvent to raw powders such as barium silicate glass and borosilicate glass is used on a connecting portion between the electrode 3 and the lead 4 using a dispenser or the like. In addition, an excessive supply is made in a mountain shape that completely covers these. Next, the insulating substrate 1 containing the slurry is fired at a high temperature (about 800 to 1200 ° C.) and cooled to room temperature (cooled), thereby producing the covering member 6 that completely covers the connecting portion.

  According to such a temperature measuring body 10, it is possible to achieve high accuracy in detecting a temperature change.

  Such temperature detection using the temperature measuring element 10 is, for example, in the case of a measuring instrument that measures the temperature of exhaust gas from a device having a combustion section such as an internal combustion engine (gasoline engine, diesel engine, etc.), a gas turbine, or a boiler. If there is, it is done as follows. That is, first, the temperature measuring body 10 is mounted on the external substrate including the circuit for measuring electric resistance as described above, and the lead 4 is electrically connected to a predetermined portion of the circuit of the external substrate to obtain a sensor device. Examples of the electrical connection means include connection means such as soldering the two. Next, the temperature measuring element 10 mounted on the sensor device is mounted in the exhaust gas flow path. In this case, it is sufficient that at least the temperature measuring body 10 can be positioned in the exhaust gas, and other portions of the external substrate do not necessarily have to be positioned in the exhaust gas. Thereafter, the electric resistance between the first and second ends of the resistance wire 2 included in the temperature measuring body 10 and the temperature measuring body 10 changes according to the temperature of the exhaust gas, and this electric resistance value is used for electric circuit measurement. Measured with a circuit. Based on the measured electrical resistance, for example, the temperature of the resistance wiring 2, that is, the temperature of the portion where the temperature measuring body 10 including the resistance wiring 2 is located is detected from the previously measured electrical resistance-temperature relationship. be able to.

  The line width of the resistance wiring 2 is the temperature measurement accuracy, temperature range, thickness and length of the resistance wiring 2, conditions such as the distance from the outer periphery of the insulating layer 1a to the resistance wiring 2, and productivity, In addition, it is appropriately set according to conditions such as economy.

For example, the temperature range to be detected is a high temperature range of about 500 to 1000 ° C., the resistance wiring 2 is made of platinum (so-called pure platinum having a platinum content of 99.99% by mass or more), and the thickness is about 5 to 5 ° C. 15
In the case of about μm, the line width of the resistance wiring 2 is set to about 20 to 200 μm, for example.

  In consideration of such thickness setting of the resistance wiring 2, it is preferable that the insulating layer 1a is made of a ceramic sintered body and the resistance wiring 2 is a thick film conductor. The resistance wiring 2 in this case is formed by, for example, simultaneous firing with the insulating base 1 (the plurality of insulating layers 1a). If the resistance wiring 2 is a thick film conductor, it is easy to make the thickness relatively thick, such as about 10 μm or more as described above. In addition, since such a relatively thick resistance wiring 2 can be formed by simultaneous firing with the insulating substrate 1, the bonding strength between the resistance wiring 2 and the insulating substrate 1 and the productivity as the temperature measuring body 10 are obtained. It is advantageous. Moreover, the pattern of the resistance wiring 2 can be easily set only by adjusting the printing pattern of the metal paste that becomes the resistance wiring 2. Therefore, it is advantageous in terms of design freedom and productivity.

  Further, as described above, the resistance wiring 2 has a meander shape having a plurality of linear portions arranged in parallel to each other and a plurality of folded portions connecting ends of adjacent linear portions among the plurality of linear portions. It is. The folded portion connects the ends of a plurality of adjacent straight portions to every other end. In other words, a plurality of linear portions and a plurality of folded portions are sequentially connected in series to form one meandering pattern (meandering pattern).

When the resistance wiring 2 has a meander-like pattern, the relatively long resistance wiring 2 is sequentially folded and arranged, which is advantageous in providing the longest resistance wiring 2 between one layer. When the length of the resistance wiring 2 is longer, the electrical resistance between the first and second ends of the resistance wiring 2 can be further increased. That is, for example, since the electrical resistance of the resistance wiring 2 at a reference temperature (normal temperature or the like) is relatively large, the absolute value of the change in electrical resistance according to the temperature change is larger. Therefore, accurate temperature measurement becomes easy from room temperature to a high temperature range such as about 1000 ° C.

  Further, for example, as in the example of FIGS. 1 to 5, when the insulating layer 1 a has a quadrangular shape, and the resistance wiring 2 has a meander shape, the straight line portion and the folded portion of the meandering resistance wiring 2. If the part is arranged in parallel to the outer periphery of the insulating layer 1a, the following effects can be obtained. In other words, in this case, the distance from the outer periphery of the insulating layer 1a to the resistance wiring 2 closest to the outer periphery is made substantially the same distance in each of the straight portion and the folded portion. Therefore, there is a possibility that the distance from the outer periphery of the insulating layer 1a to the resistance wiring 2 is partially extremely close in each of the straight portion and the folded portion, and platinum of the resistance wiring 2 is easily sublimated to the outside. Is reduced.

  Further, in this case, the widths of the relatively wide portions are the same between the linear portion and the folded portion, and further, between the outer periphery of the insulating layer 1a and each of the linear portion and the folded portion. The distance may be the same. In this case, the distance from the outer periphery to the resistance wiring 2 is made substantially the same in almost the entire outer periphery of the insulating layer 1a. Therefore, the possibility that the sublimation of platinum to the outside is promoted in a part of the length direction of the resistance wiring 2 can be further reduced.

  Therefore, the temperature sensing element 10 has a meandering shape when the resistance wiring 2 places importance on the accuracy of temperature measurement, long-term reliability, etc., and the straight line portion and the folded portion are parallel to the outer periphery of the insulating layer 1a. It is preferable to arrange | position. Further, when the insulating layer 1a (insulating base 1) has a quadrangular shape, for example, the temperature measuring element is in the form of a multi-piece substrate in which a plurality of regions to be such an insulating base are arranged and formed on one mother board. When producing 10, the arrangement is easy. That is, it is more advantageous in productivity and economy as the temperature measuring element 10.

  In the example of FIGS. 1 to 5, the shape of the insulating substrate 1 is a quadrangular (rectangular) plate shape, that is, a rectangular plate shape, and the resistance wiring 2 having a meandering pattern has a rectangular linear insulating portion 1a. It is arranged along the long side direction of (interlayer). Moreover, the folding | turning part is arrange | positioned along the short side direction. In this case, for example, the following advantageous effects can be obtained when the metal paste to be the resistance wiring 2 is applied by a method such as screen printing. That is, in the printing method, the metal paste is likely to be blurred at the folded portion (the boundary portion between the folded portion and the straight portion). For this reason, reducing the folding can reduce blurring and increase the overall resistance value of the resistance wiring 2. In this embodiment, since the folding is shorter than the case where the length of the straight portion is short and the number of the folding portions is large, it is easier to increase the overall resistance value.

  The temperature measuring element 10 of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, the resistance wiring 2 may be disposed between four or more layers. Further, the resistance wiring 2 of the temperature measuring body 10 is not limited to the meander conductor, and may be another pattern.

DESCRIPTION OF SYMBOLS 1 ... Insulation base | substrate 1a .... Insulation layer 2 ... Resistance wiring 3 ... Electrode 3a ... First electrode 3b ... Second electrode 4 ... Lead 4a ... Recess 4b ... Projection part 5 ..Connection conductor 6 ... covering member
10 ... RTD

Claims (6)

A rectangular plate-shaped insulating substrate;
Resistance wiring provided on the insulating substrate;
A first electrode and a second electrode provided on one main surface of the insulating base;
A lead connected to each of the first electrode and the second electrode;
A temperature measuring element having a recess and a protrusion connected to the inner wall of the recess on the surface of the lead.   The temperature measuring body according to claim 1, wherein the protruding portion protrudes toward the outside of the concave portion.   The temperature measuring body according to claim 1, wherein the protrusion is provided so as to surround the recess when seen in a plan view.   4. The temperature measuring element according to claim 1, wherein the concave portion has a rectangular shape in a plan view and is inclined with respect to a longitudinal direction of the lead. 5.   The temperature measuring element according to any one of claims 1 to 4, wherein the concave portions are arranged in a staggered manner in a plan view.   2. A covering member made of a glass material, including the concave portion and the protruding portion, and covering a connecting portion of the lead with the first electrode and the second electrode. Item 6. The temperature measuring element according to any one of Items 5 to 6.

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