Temperature Sensor

Abstract

The present disclosure addresses the problem of suppressing a deterioration in temperature detection accuracy. A temperature sensor (1) according to the present invention comprises an alumina substrate, a flattening film (12), a first resistance part (131), and at least one second resistance part (141, 142, 143). The flattening film (12) has alumina as the main component thereof and is formed on the alumina substrate. The first resistance part (131) is formed on the flattening film (12). The second resistance part (141, 142, 143) is formed on the flattening film (12) and, with the first resistance part (131), constitutes a bridge circuit.

Description

[Technical Field]

[0001] The present disclosure relates generally to temperature sensors, and more particularly to temperature sensors including a first resistive portion and a second resistive portion. [Background technology]

[0002] Patent document 1 describes a temperature detection device (temperature sensor) that includes a boron-treated first resistor (first resistor portion) and a second resistor (second resistor portion) whose absolute value of the temperature coefficient is larger than that of the first resistor.

[0003] The temperature detection device described in Patent Document 1 detects temperature based on the difference in resistance between a first resistor and a second resistor.

[0004] In the temperature detection device described in Patent Document 1, the temperature detection accuracy may be degraded. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2014 / 200011 Summary of the Invention

[0006] An object of the present disclosure is to provide a temperature sensor that can suppress deterioration in temperature detection accuracy.

[0007] A temperature sensor according to one embodiment of the present disclosure includes an alumina substrate, a planarization film, a first resistor, and at least one second resistor. The planarization film is primarily composed of alumina and is formed on the alumina substrate. The first resistor is formed on the planarization film. The second resistor is formed on the planarization film and forms a bridge circuit with the first resistor. At least one of the first and second resistors has an adjustment portion for adjusting the resistance value of the specific resistor, the adjustment portion being a groove formed in the specific resistor. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of the appearance of a temperature sensor according to an embodiment. [Figure 2] FIG. 2 is a plan view of the temperature sensor. [Figure 3] FIG. 3 is an enlarged view of a portion A1 in FIG. 2, relating to the temperature sensor. [Figure 4] 4 is a cross-sectional view of the temperature sensor taken along line X1-X1 in FIG. [Figure 5] 5 is a cross-sectional view of the temperature sensor taken along line X2-X2 in FIG. 1. FIG. [Figure 6] FIG. 6 is a cross-sectional view of the temperature sensor taken along line Y1-Y1 in FIG. [Figure 7] FIG. 7 is a schematic circuit diagram of the temperature sensor. [Figure 8] FIG. 8 is another plan view of the temperature sensor. DETAILED DESCRIPTION OF THE INVENTION

[0009] The temperature sensor 1 according to the embodiment will be described below with reference to Figures 1 to 8. Figures 1 to 6 and 8 referred to in the following embodiments are all schematic diagrams, and the ratios of sizes and thicknesses of the components in the figures do not necessarily reflect the actual dimensional ratios.

[0010] (Embodiment) (1) Overview The temperature sensor 1 according to the embodiment is an electronic component for measuring temperature. The temperature sensor 1 is, for example, a surface-mounted chip component that is mounted on the surface (mounting surface) of an external substrate (not shown) via a plurality of (for example, four) electrode portions 16 described below. The external substrate is, for example, a printed wiring board.

[0011] 1, the temperature sensor 1 according to the embodiment includes a support substrate 11 (alumina substrate), a planarization film 12, a first resistor portion 131, and at least one (three in the illustrated example) second resistor portion 141, 142, 143. The planarization film 12 is mainly composed of alumina and is formed on the support substrate 11. The first resistor portion 131 is formed on the planarization film 12. The second resistor portions 141, 142, 143 are formed on the planarization film 12 and form a bridge circuit with the first resistor portion 131.

[0012] In the temperature sensor 1 according to the embodiment, as described above, the first resistor 131 and the second resistors 141, 142, and 143 are formed on the planarization film 12 formed on the support substrate 11. This allows the first resistor 131 and the second resistors 141, 142, and 143 to be more planarized than when the first resistor 131 and the second resistors 141, 142, and 143 are formed directly on the support substrate 11 without the planarization film 12 in between. This makes it possible to suppress deterioration in temperature detection accuracy. Furthermore, in the temperature sensor 1 according to the embodiment, as described above, the main component of the planarization film 12 is alumina. This allows for improved adhesion between the support substrate 11, which is made of an alumina substrate, and the planarization film 12.

[0013] In the present disclosure, the "main component of the planarization film" refers to the component that accounts for the largest proportion of the planarization film among the components that make up the planarization film. In the temperature sensor 1 according to the embodiment, the main component of the planarization film 12 is alumina, and the proportion of alumina in the planarization film 12 is the largest.

[0014] (2) Details The temperature sensor 1 according to the embodiment will be described in detail below with reference to FIGS.

[0015] (2.1) Temperature sensor structure First, the structure of a temperature sensor 1 according to the embodiment will be described with reference to FIGS.

[0016] As shown in Fig. 1, the temperature sensor 1 according to the embodiment is formed in a rectangular parallelepiped shape that is long along a first direction D1. In the following description, the longitudinal direction of the temperature sensor 1 is the first direction D1, the width direction (short-side direction) of the temperature sensor 1 is the second direction D2, and the thickness direction of the temperature sensor 1 is the third direction D3; however, these directions are not intended to limit the directions of the temperature sensor 1 when in use. Furthermore, the arrows indicating "D1," "D2," and "D3" in the drawings are merely shown for the purpose of explanation and do not represent any physical entity. In this embodiment, the first direction D1, the second direction D2, and the third direction D3 are perpendicular to one another.

[0017] 1 to 6, the temperature sensor 1 according to the embodiment includes a support substrate 11, a planarization film 12, a first resistance layer 13, and a second resistance layer 14. The temperature sensor 1 also includes a protective film 15, a plurality of (for example, four) electrode portions 16, a plurality of (four in the illustrated example) first plating layers 17, and a plurality of (four in the illustrated example) second plating layers 18.

[0018] The support substrate 11 is, for example, a ceramic substrate. The material of the ceramic substrate is, for example, an alumina sintered body with an alumina content of 96% or more. That is, the support substrate 11 is an alumina substrate made of an alumina sintered body. The support substrate 11 is formed in a rectangular shape that is long in a first direction D1 that is the longitudinal direction of the temperature sensor 1 when viewed from a third direction D3 that is the thickness direction of the temperature sensor 1. As shown in FIGS. 4 to 6, the support substrate 11 has a first main surface 111, a second main surface 112, and an outer peripheral surface 113. Each of the first main surface 111 and the second main surface 112 is a plane that extends along both the first direction D1 and a second direction D2 that is the width direction (short direction) of the temperature sensor 1. In other words, each of the first main surface 111 and the second main surface 112 is a plane that intersects (is perpendicular to) the third direction D3. The first main surface 111 and the second main surface 112 face each other in the third direction D3. The outer peripheral surface 113 includes four side surfaces connecting the first main surface 111 and the second main surface 112. Each of the four side surfaces is a flat surface extending along the third direction D3.

[0019] As shown in FIGS. 4 to 6, the planarization film 12 is formed on the first main surface 111 of the support substrate 11. The planarization film 12 is mainly composed of alumina (Al2O3), for example. That is, alumina accounts for the largest proportion of the components constituting the planarization film 12, for example, 50 mass% or more. The proportion of alumina in the planarization film 12 is preferably 80 mass% or more, and more preferably 90 mass% or more. In the temperature sensor 1 according to the embodiment, the planarization film 12 contains a filler. The filler contains at least one material selected from the group consisting of zinc oxide (ZnO), magnesium oxide (MgO), beryllium oxide (BeO), aluminum nitride (AlN), boron nitride (BN), silicon nitride (SiNx), and diamond. This allows the thermal conductivity and linear expansion coefficient of the planarization film 12 to be closer to those of the support substrate (alumina substrate) 11.

[0020] As described above, the main component of the planarization film 12 is alumina. Therefore, when the planarization film 12 is formed on the support substrate 11 made of an alumina substrate, a difference in thermal expansion coefficient is unlikely to occur between the support substrate 11 and the planarization film 12 even when subjected to a thermal load. Furthermore, since the materials of the support substrate 11 and the planarization film 12 are similar, the planarization film 12 has excellent insulating properties and thermal conductivity, just like the support substrate 11.

[0021] Here, the surface of a typical alumina substrate has irregularities of several hundred to several thousand nanometers due to the shape of the alumina particles that make up the alumina sintered body. Therefore, it is preferable that the thickness of the planarization film 12 is equal to or greater than the height of the irregularities. Specifically, it is preferable that the thickness of the planarization film 12 is, for example, 1.0 μm or greater. This makes it possible to form the first resistance layer 13 and the second resistance layer 14 on the surface (upper surface) of the planarization film 12, where irregularities are suppressed.

[0022] 4 to 6, the first resistance layer 13 is formed on the planarization film 12. The material of the first resistance layer 13 includes, for example, platinum (Pt). The first resistance layer 13 is, for example, a sputtered film formed by sputtering.

[0023] The first resistance layer 13 includes a first resistance portion 131 serving as a resistance temperature detector. That is, the first resistance portion 131 is formed on the planarizing film 12, and is made of platinum. As shown in FIGS. 2 and 3, the first resistance portion 131 is formed in a meandering shape that meanders along the first direction D1 when viewed from a plane in the third direction D3. In other words, the first resistance portion 131 is formed in a river-like shape that meanders along the first direction D1 when viewed from a plane in the third direction D3.

[0024] As shown in FIGS. 4 to 6, the second resistance layer 14 is formed on the planarizing film 12. The material of the second resistance layer 14 is, for example, a NiCrAlSi alloy. In the second resistance layer 14, the weight ratio of nickel (Ni) to chromium (Cr) is, for example, 44 / 55 or more and 55 / 44 or less. In the second resistance layer 14, the proportion of aluminum (Al) to the total weight is, for example, 10% by weight or more and 18% by weight or less. In the second resistance layer 14, the proportion of silicon (Si) to the total weight is, for example, 2% by weight or more and 6% by weight or less. The second resistance layer 14 is, for example, a sputtered film formed by sputtering.

[0025] As shown in FIGS. 1 and 2, the second resistance layer 14 includes a plurality of (three in the illustrated example) second resistance portions 141, 142, and 143. That is, the second resistance portions 141, 142, and 143 are formed on the planarization film 12, and the material of the second resistance portions 141, 142, and 143 includes a NiCrAlSi alloy. Each of the second resistance portions 141, 142, and 143 is formed in a rectangular shape that is elongated in one direction when viewed from a plane in the third direction D3. More specifically, of the second resistance portions 141, 142, and 143, the second resistance portion 141 is formed in a rectangular shape that is elongated in the first direction D1. Furthermore, each of two of the second resistance portions 142 and 143 among the second resistance portions 141, 142, and 143 is formed in a rectangular shape that is elongated in the second direction D2.

[0026] Two of the multiple second resistor portions 141, 142, and 143 are arranged at both ends of the support substrate 11 in the first direction D1 in a plan view from the third direction D3. That is, the two second resistor portions 142 and 143 are aligned along the first direction D1. The remaining second resistor portion 141 of the multiple second resistor portions 141, 142, and 143 is arranged at one end (the lower end in FIG. 2) of the support substrate 11 in the second direction D2 in a plan view from the third direction D3. The above-mentioned first resistor portion 131 is arranged at the other end (the upper end in FIG. 2) of the support substrate 11 in the second direction D2. That is, the first resistor portion 131 and the second resistor portion 141 are aligned along the second direction D2.

[0027] As described above, the material of the first resistor portion 131 contains platinum. Furthermore, the material of the second resistor portions 141, 142, and 143 contains a NiCrAlSi alloy, as described above. Therefore, in the temperature sensor 1 according to this embodiment, the temperature coefficient of resistance of the first resistor portion 131 is greater than the temperature coefficient of resistance of the second resistor portions 141, 142, and 143. This allows the first resistor portion 131 to detect temperature changes.

[0028] The protective film 15 is a film for protecting the first resistance layer 13 and the second resistance layer 14. As shown in FIGS. 4 to 6, the protective film 15 is formed so as to cover the first resistance layer 13 and the second resistance layer 14. The material of the protective film 15 is, for example, silicon dioxide (SiO2). In the temperature sensor 1 according to the embodiment, the protective film 15 does not cover the connection portion between the first resistance portion 131 of the first resistance layer 13 and the electrode portion 16 described below. In the temperature sensor 1, the protective film 15 does not cover the connection portion between each of the plurality of second resistance portions 141, 142, and 143 of the second resistance layer 14 and the electrode portion 16.

[0029] As shown in FIG. 1 , each of the plurality of electrode portions 16 is formed at one of the four corners of the support substrate 11. The material of the plurality of electrode portions 16 is, for example, a copper-nickel (CuNi) alloy. Each of the plurality of electrode portions 16 includes an upper electrode 161, an end electrode 162, and a lower electrode 163. The upper electrode 161 is formed on the first main surface 111 of the support substrate 11 and is connected to a connection portion with the first resistor portion 131 of the first resistor layer 13 or a connection portion with the second resistor portions 141, 142, and 143 of the second resistor layer 14. The end electrode 162 is formed along the longitudinal direction (first direction D1) of the support substrate 11 so as to cover the outer circumferential surface 113 of the support substrate 11 in the longitudinal direction. The lower electrode 163 is formed on the second main surface 112 of the support substrate 11. Each of the plurality of electrode portions 16 is formed in a U-shape when viewed from the first direction D1. Each of the plurality of electrode portions 16 is, for example, a sputtered film formed by sputtering.

[0030] The multiple electrode portions 16 include a first electrode portion 16A, a second electrode portion 16B, a third electrode portion 16C, and a fourth electrode portion 16D. The first electrode portion 16A is, for example, a power supply terminal. The second electrode portion 16B is, for example, a ground terminal. The third electrode portion 16C is, for example, a first output terminal. The fourth electrode portion 16D is, for example, a second output terminal. That is, in the temperature sensor 1 according to the embodiment, DC power is supplied from a power supply device (not shown) so that the first electrode portion 16A is the positive (plus) side and the second electrode portion 16B is the negative (minus) side.

[0031] Each of the multiple first plating layers 17 is, for example, an electrolytic copper plating layer. Each of the multiple first plating layers 17 is formed so as to cover a corresponding one of the multiple electrode portions 16. That is, each of the multiple first plating layers 17 covers the upper surface electrode 161, the end surface electrode 162, and the lower surface electrode 163 of the corresponding electrode portion 16. Each of the multiple first plating layers 17 is formed in a U-shape when viewed in a plan view from the first direction D1.

[0032] Each of the plurality of second plating layers 18 is, for example, an electrolytic tin plating layer. Each of the plurality of second plating layers 18 is formed so as to cover a corresponding one of the plurality of first plating layers 17. Each of the plurality of second plating layers 18 is formed in a U-shape when viewed in a plan view from the first direction D1.

[0033] (2.2) Temperature sensor circuit configuration Next, the circuit configuration of the temperature sensor 1 according to the embodiment will be described with reference to FIG.

[0034] 7, the temperature sensor 1 according to the embodiment includes a first resistor 131 and a plurality of (three in the illustrated example) second resistors 141, 142, and 143. The temperature sensor 1 also includes a first electrode 16A, a second electrode 16B, a third electrode 16C, and a fourth electrode 16D. As described above, the first electrode 16A is a power supply terminal, the second electrode 16B is a ground terminal, the third electrode 16C is a first output terminal, and the fourth electrode 16D is a second output terminal.

[0035] As shown in FIG. 7 , a first end of the first resistor 131 is connected to a first end of the second resistor 143 at point P1. A second end of the first resistor 131 is connected to a second end of the second resistor 142 at point P3. A second end of the second resistor 143 is connected to a second end of the second resistor 141 at point P4. A first end of the second resistor 141 is connected to a first end of the second resistor 141 at point P2. That is, the temperature sensor 1 according to the embodiment includes three second resistors 141, 142, and 143 as second resistors. The first resistor 131 and the three second resistors 141, 142, and 143 form a full-bridge circuit. This allows the detection voltage to be amplified more than when the first resistor and the second resistor form a half-bridge circuit.

[0036] 7, in the temperature sensor 1 according to the embodiment, the first electrode portion 16A is connected to the first resistor portion 131 and the second resistor portion 143 via a first connection portion 132. The first connection portion 132 is a connection portion between the first electrode portion 16A and the first resistor portion 131 and the second resistor portion 143 of the first resistor layer 13. In the temperature sensor 1, the second electrode portion 16B is connected to the two second resistor portions 141 and 142 via a second connection portion 133. The second connection portion 133 is a connection portion between the two second resistor portions 141 and 142 of the second resistor layer 14 and the second electrode portion 16B. In the temperature sensor 1, the third electrode portion 16C is connected to the first resistor portion 131 and the second resistor portion 142 via a third connection portion 134. The third connection portion 134 is a connection portion between the first resistance portion 131 and the second resistance portion 142 of the first resistance layer 13 and the third electrode portion 16C. In the temperature sensor 1, the fourth electrode portion 16D is connected to the two second resistance portions 141 and 143 via the fourth connection portion 135. The fourth connection portion 135 is a connection portion between the two second resistance portions 141 and 143 of the second resistance layer 14 and the fourth electrode portion 16D.

[0037] In the temperature sensor 1 configured in this manner, a power supply device (not shown) is connected between the first electrode portion 16A and the second electrode portion 16B so that the first electrode portion 16A is the positive (plus) side and the second electrode portion 16B is the negative (minus) side. When DC power from the power supply device is supplied between the first electrode portion 16A and the second electrode portion 16B, a detection voltage (output signal) corresponding to the detected temperature is output from the third electrode portion 16C and the fourth electrode portion 16D to the outside (for example, an external board). A measurement circuit mounted on the external board then calculates the detected temperature based on the detection voltage from the temperature sensor 1.

[0038] (3) Temperature sensor manufacturing method Next, a method for manufacturing the temperature sensor 1 according to the embodiment will be described.

[0039] The method for manufacturing the temperature sensor 1 includes first to tenth steps.

[0040] In the first step, the support substrate 11 is prepared. More specifically, in the first step, a substrate body that will become the base of the support substrate 11 of each of the plurality of temperature sensors 1 is prepared. The substrate body is, for example, a ceramic substrate. The material of the ceramic substrate that becomes the substrate body is, for example, an alumina sintered body with an alumina content of 96% or more.

[0041] In the second step, a planarization film 12 is formed on the first main surface of the substrate body. More specifically, in the second step, for example, a material for the planarization film 12 is applied to the first main surface of the substrate body, and then the planarization film 12 is formed by baking. The first main surface of the substrate body is a surface that becomes the first main surface 111 of the support substrate 11 of each of the multiple temperature sensors 1.

[0042] In the third step, the first resistance layer 13 and the second resistance layer 14 are formed for each of the plurality of temperature sensors 1. More specifically, in the third step, the first resistance layer 13 and the second resistance layer 14 are formed on the planarization film 12 by, for example, sputtering. Also in the third step, the first resistance portion 131 in the first resistance layer 13 is patterned by, for example, photolithography so that the shape of the first resistance portion 131 has a meandering shape.

[0043] In the fourth step, the protective film 15 is formed. More specifically, in the fourth step, for example, a silicon dioxide paste is applied by screen printing onto the planarization film 12 so as to cover a portion of the first resistance layer 13 and the second resistance layer 14, and then the paste is baked to form the protective film 15. Here, in the fourth step, the protective film 15 is formed so as to cover at least the region excluding the connection portion between the first resistance portion 131 and the electrode portion 16 and the connection portions between each of the second resistance portions 141, 142, and 143 and the electrode portion 16.

[0044] In the fifth step, the plurality of upper surface electrodes 161 for each of the plurality of temperature sensors 1 are formed on the first main surface of the substrate body. More specifically, in the fifth step, the plurality of upper surface electrodes 161 for each of the plurality of temperature sensors 1 are formed by, for example, forming a copper-nickel alloy film on the first main surface of the substrate body by sputtering.

[0045] In the sixth step, a plurality of lower electrodes 163 for each of the plurality of temperature sensors 1 are formed on the second main surface of the substrate body. More specifically, in the sixth step, a copper-nickel alloy film is formed on the second main surface of the substrate body by, for example, sputtering, thereby forming a plurality of lower electrodes 163 for each of the plurality of temperature sensors 1. The second main surface of the substrate body is the surface that becomes the second main surface 112 of the support substrate 11 for each of the plurality of temperature sensors 1.

[0046] In the seventh step, the plurality of temperature sensors 1 integrally formed in the first to sixth steps are cut into individual temperature sensors 1. More specifically, in the seventh step, the plurality of temperature sensors 1 integrally formed are cut into individual temperature sensors 1 using, for example, a laser or dicing.

[0047] In the eighth step, a plurality of end electrodes 162 are formed on the individually cut temperature sensors 1. More specifically, in the eighth step, a copper-nickel alloy film is formed on the outer peripheral surface 113 of the support substrate 11 by sputtering, for example, to form the plurality of end electrodes 162 on each of the plurality of temperature sensors 1. As a result, the plurality of upper electrodes 161 and the plurality of lower electrodes 163 are connected via the plurality of end electrodes 162.

[0048] In the ninth step, a plurality of first plating layers 17 are formed on each of the plurality of temperature sensors 1. More specifically, in the ninth step, for example, a plurality of first plating layers 17 are formed on each of the plurality of temperature sensors 1 so as to cover a plurality of electrode portions 16.

[0049] In the tenth step, a plurality of second plating layers 18 are formed on each of the plurality of temperature sensors 1. More specifically, in the tenth step, for example, a plurality of second plating layers 18 are formed on each of the plurality of temperature sensors 1 so as to cover the plurality of first plating layers 17.

[0050] The temperature sensor 1 according to the embodiment can be manufactured through the first to tenth steps described above.

[0051] (4) Adjusting the resistance value (trimming) Next, adjustment of the resistance value of the temperature sensor 1 according to the embodiment will be described with reference to FIGS. 2, 3 and 8. FIG.

[0052] (4.1) When the first electrode is a power terminal When the first electrode portion 16A is a power terminal as in the temperature sensor 1 according to the embodiment, the second electrode portion 16B is a ground terminal.

[0053] When the potential of the third electrode portion 16C serving as the first output terminal is higher than the potential of the fourth electrode portion 16D serving as the second output terminal, as shown in FIGS. 2 and 3, an adjustment portion 130 is formed in the first resistor portion 131, and an adjustment portion 140 is formed in the second resistor portion 141. The adjustment portion 130 is a groove formed in the first resistor portion 131. The adjustment portion 140 is a groove formed in the second resistor portion 141. In the example of FIGS. 2 and 3, the first resistor portion 131 has a plurality of adjustment portions 130 (two in the illustrated example). In a plan view from the third direction D3, one of the plurality of adjustment portions 130 has an elliptical shape that is elongated along the first direction D1, and the other has an elliptical shape that is elongated along the second direction D2. In the example of FIGS. 2 and 3, the second resistor portion 141 has one adjustment portion 140. In a plan view from the third direction D3, the adjustment portion 140 has an L-shape. This makes it possible to make the potential of the third electrode portion 16C equal to the potential of the fourth electrode portion 16D. In this case, the first resistance portion 131 and the second resistance portion 141 are the specified resistance portions.

[0054] On the other hand, when the potential of the fourth electrode portion 16D is greater than the potential of the third electrode portion 16C, an adjustment portion 140 is formed in each of the two second resistor portions 142, 143, as shown in FIG. 8. The adjustment portion 140 is a groove formed in each of the second resistor portions 142, 143. In the example of FIG. 8, each of the second resistor portions 142, 143 has one adjustment portion 140. In a plan view from the third direction D3, each adjustment portion 140 has an L-shape. This makes it possible to equalize the potential of the third electrode portion 16C and the potential of the fourth electrode portion 16D. In this case, the two second resistor portions 142, 143 are specific resistor portions.

[0055] (4.2) When the second electrode is a power terminal When the second electrode portion 16B is a power terminal, the first electrode portion 16A is a ground terminal.

[0056] When the potential of the third electrode portion 16C serving as the first output terminal is greater than the potential of the fourth electrode portion 16D serving as the second output terminal, an adjustment portion 140 is formed in each of the two second resistor portions 142, 143, as shown in FIG. 8. The adjustment portion 140 is a groove formed in each of the second resistor portions 142, 143. In the example of FIG. 8, each of the second resistor portions 142, 143 includes one adjustment portion 140. In a plan view from the third direction D3, each adjustment portion 140 has an L-shape. This makes it possible to equalize the potential of the third electrode portion 16C and the potential of the fourth electrode portion 16D. In this case, the two second resistor portions 142, 143 are specific resistor portions.

[0057] On the other hand, when the potential of the fourth electrode portion 16D is higher than the potential of the third electrode portion 16C, as shown in FIGS. 2 and 3, an adjustment portion 130 is formed in the first resistor portion 131, and an adjustment portion 140 is formed in the second resistor portion 141. The adjustment portion 130 is a groove formed in the first resistor portion 131. The adjustment portion 140 is a groove formed in the second resistor portion 141. In the example of FIGS. 2 and 3, the first resistor portion 131 has a plurality of adjustment portions 130 (two in the illustrated example). In a plan view from the third direction D3, one of the plurality of adjustment portions 130 has an elliptical shape that is elongated along the first direction D1, and the other has an elliptical shape that is elongated along the second direction D2. In the example of FIGS. 2 and 3, the second resistor portion 141 has one adjustment portion 140. In a plan view from the third direction D3, the adjustment portion 140 has an L-shape. This makes it possible to make the potential of the third electrode portion 16C equal to the potential of the fourth electrode portion 16D. In this case, the first resistance portion 131 and the second resistance portion 141 are the specified resistance portions.

[0058] (5) Effects In the temperature sensor 1 according to the embodiment, as described above, the first resistor 131 and the plurality of second resistors 141, 142, 143 are formed on the planarization film 12 formed on the support substrate 11. This makes it possible to planarize the first resistor 131 and the plurality of second resistors 141, 142, 143 more than when the first resistor 131 and the plurality of second resistors 141, 142, 143 are formed on the support substrate 11 without the planarization film 12. As a result, the rough surface of the support substrate 11 does not directly affect the surface roughness of the first resistor 131 and the second resistors 141, 142, 143, making it possible to suppress deterioration in temperature detection accuracy.

[0059] In the temperature sensor 1 according to the embodiment, as described above, the planarization film 12 contains at least one material selected from the group consisting of zinc oxide, magnesium oxide, beryllium oxide, aluminum nitride, boron nitride, silicon nitride, and diamond. This allows the thermal conductivity and linear expansion coefficient of the planarization film 12 to be closer to those of the support substrate 11.

[0060] As described above, in the temperature sensor 1 according to the embodiment, the material of the first resistor 131 contains platinum, which makes it possible to obtain a good temperature coefficient of resistance relative to temperature.

[0061] As described above, in the temperature sensor 1 according to the embodiment, the material of the second resistor portions 141, 142, and 143 includes a NiCrAlSi alloy, which allows the second resistor portions 141, 142, and 143 to be used as reference resistors whose temperature coefficient of resistance is substantially zero.

[0062] As described above, in the temperature sensor 1 according to the embodiment, a full-bridge circuit is configured by the first resistor section 131 and three second resistor sections 141, 142, and 143. This makes it possible to amplify the detection voltage compared to when a half-bridge circuit is configured by the first resistor section and the second resistor section.

[0063] As described above, the temperature sensor 1 according to the embodiment further includes the third electrode portion 16C and the fourth electrode portion 16D that output an output signal from the full bridge circuit configured with the first resistor portion 131 and the three second resistor portions 141, 142, and 143. This makes it possible to output the output signal from the full bridge circuit to the outside.

[0064] In the temperature sensor 1 according to the embodiment, as described above, the first resistor portion 131 and the second resistor portion 141 have the adjustment portions 130, 140. This makes it possible to adjust the resistance values ​​of the first resistor portion 131 and the second resistor portion 141, and as a result, it becomes possible to equalize the potential of the third electrode portion 16C and the potential of the fourth electrode portion 16D. Furthermore, since each of the adjustment portions 130, 140 is a groove formed in the first resistor portion 131 or the second resistor portion 141, it becomes possible to easily adjust the resistance values ​​of the first resistor portion 131 and the second resistor portion 141.

[0065] (6) Variations The above-described embodiment is merely one of various embodiments of the present disclosure. The above-described embodiment can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Modifications of the above-described embodiment are listed below. The modifications described below can be applied in appropriate combinations.

[0066] In the above-described embodiment, the material of the first resistor portion 131 is platinum, but the material of the first resistor portion 131 is not limited to platinum. The material of the first resistor portion 131 may include, for example, nickel (Ni), copper (Cu), or a nickel-cobalt (NiCo) alloy. The material of the first resistor portion 131 may also include two or more of platinum, nickel, copper, and a nickel-cobalt alloy. In short, the material of the first resistor portion 131 may include at least one of platinum, nickel, copper, and a nickel-cobalt alloy.

[0067] In the above-described embodiment, the shapes of the adjustment section 130 of the first resistor section 131 and the adjustment section 140 of the second resistor section 141 are merely examples, and other shapes may be used. That is, the shapes of the adjustment sections 130, 140 may be any shapes that allow the resistance value of the first resistor section 131 and the resistance value of the second resistor section 141 to be adjusted.

[0068] In the above-described embodiment, a full-bridge circuit is formed by one first resistance section 131 and three second resistance sections 141, 142, and 143, but, for example, a half-bridge circuit may be formed by one first resistance section and one second resistance section.

[0069] In the above-described embodiment, the adjustment unit is formed in two resistance units (the first resistance unit 131 and the second resistance unit 141, or the two second resistance units 142 and 143), but it is sufficient if the adjustment unit is formed in at least one of them. For example, when the first resistance unit 131 and the second resistance unit 141 are specific resistance units, the adjustment unit 130 may be formed only in the first resistance unit 131, or the adjustment unit 140 may be formed only in the second resistance unit 141.

[0070] In the above-described embodiment, the material of the electrode portion 16 is a copper-nickel alloy, but the material of the electrode portion 16 is not limited to a copper-nickel alloy and may be, for example, an alloy containing gold.

[0071] (Aspect) The present specification discloses the following aspects.

[0072] The temperature sensor (1) according to the first aspect includes an alumina substrate (11), a planarization film (12), a first resistor portion (131), and at least one second resistor portion (141, 142, 143). The planarization film (12) is mainly composed of alumina and is formed on the alumina substrate (11). The first resistor portion (131) is formed on the planarization film (12). The second resistor portions (141, 142, 143) are formed on the planarization film (12) and form a bridge circuit with the first resistor portion (131).

[0073] According to this aspect, it is possible to suppress deterioration in the accuracy of temperature detection.

[0074] In the temperature sensor (1) according to the second aspect, in the first aspect, the planarizing film (12) contains a filler.

[0075] According to this embodiment, the thermal conductivity and linear expansion coefficient of the planarizing film (12) can be made close to those of the alumina substrate (11).

[0076] In the temperature sensor (1) according to the third aspect, in the second aspect, the filler contains at least one material selected from the group consisting of zinc oxide, magnesium oxide, beryllium oxide, aluminum nitride, boron nitride, silicon nitride, and diamond.

[0077] According to this embodiment, the thermal conductivity and linear expansion coefficient of the planarizing film (12) can be made close to those of the alumina substrate (11).

[0078] In the temperature sensor (1) according to the fourth aspect, in any one of the first to third aspects, the material of the first resistor portion (131) contains at least one of platinum, nickel, copper, and a nickel-cobalt alloy.

[0079] According to this aspect, it is possible to obtain a good temperature coefficient of resistance with respect to temperature.

[0080] In the temperature sensor (1) according to the fifth aspect, in any one of the first to fourth aspects, the material of the second resistor portions (141, 142, 143) includes a NiCrAlSi alloy.

[0081] According to this aspect, it is possible to use the second resistor portion (141, 142, 143) as a reference resistor whose temperature coefficient of resistance is substantially zero.

[0082] The temperature sensor (1) according to a sixth aspect is any one of the first to fifth aspects, and includes three second resistance sections (141, 142, 143) as the second resistance sections (141, 142, 143). The bridge circuit is a full bridge circuit configured with the first resistance section (131) and the three second resistance sections (141, 142, 143).

[0083] According to this aspect, it is possible to amplify the detected voltage compared to when the bridge circuit is a half bridge.

[0084] The temperature sensor (1) according to a seventh aspect is the same as that of the sixth aspect, but further includes a first electrode portion (16A), a second electrode portion (16B), a third electrode portion (16C), and a fourth electrode portion (16D). The first electrode portion (16A) and the second electrode portion (16B) supply power to the full-bridge circuit. The third electrode portion (16C) and the fourth electrode portion (16D) output an output signal from the full-bridge circuit to the outside.

[0085] According to this aspect, it becomes possible to output an output signal to the outside by the third electrode portion (16C) and the fourth electrode portion (16D).

[0086] In the temperature sensor (1) according to the eighth aspect, in any one of the first to seventh aspects, the specific resistance section (for example, the first resistance section 131 and the second resistance section 141) has an adjustment section (130, 140) for adjusting the resistance value of the specific resistance section. The specific resistance section is at least one of the first resistance section (131) and the second resistance section (141, 142, 143).

[0087] According to this embodiment, the temperature sensor (1) alone can correct the potential difference between the detection electrodes of the bridge circuit, eliminating the need for zero-point correction after mounting on an external substrate.

[0088] In the temperature sensor (1) according to the ninth aspect, in the eighth aspect, the adjustment portions (130, 140) are grooves formed in the specific resistance portions (for example, the first resistance portion 131 and the second resistance portion 141).

[0089] According to this aspect, it is possible to adjust the resistance value of the specific resistor portion simply by forming a groove in the specific resistor portion.

[0090] The configurations according to the second to ninth aspects are not essential for the temperature sensor (1) and can be omitted as appropriate. [Explanation of symbols]

[0091] 1 temperature sensor 11 Support substrate (alumina substrate) 12 Planarization film 16A 1st electrode part 16B 2nd electrode part 16C 3rd electrode part 16D 4th electrode part 130 Adjustment section 131 1st resistance section (specific resistance section) 140 Adjustment section 141,142,143 2nd resistance section (specific resistance section)

Claims

1. an alumina substrate; a planarization film formed on the alumina substrate, the planarization film being mainly composed of alumina; a first resistor portion formed on the planarization film; at least one second resistor portion formed on the planarization film and constituting a bridge circuit with the first resistor portion; a specific resistor portion, which is at least one of the first resistor portion and the second resistor portion, has an adjustment portion for adjusting a resistance value of the specific resistor portion; The adjustment portion is a groove formed in the specific resistance portion. Temperature sensor.

2. The planarization film contains a filler. The temperature sensor of claim 1 .

3. The filler comprises at least one material selected from the group consisting of zinc oxide, magnesium oxide, beryllium oxide, aluminum nitride, boron nitride, silicon nitride, and diamond. The temperature sensor according to claim 2 .

4. the material of the first resistor portion includes at least one of platinum, nickel, copper, and a nickel-cobalt alloy; The temperature sensor according to any one of claims 1 to 3.

5. the material of the second resistor portion includes a NiCrAlSi alloy; The temperature sensor according to any one of claims 1 to 4.

6. The second resistor unit includes three second resistor units, the bridge circuit is a full bridge circuit configured with the first resistor unit and the three second resistor units; The temperature sensor according to any one of claims 1 to 5.

7. a first electrode unit and a second electrode unit that supply power to the full bridge circuit; a third electrode unit and a fourth electrode unit that output an output signal from the full bridge circuit to an external device; The temperature sensor according to claim 6.

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