Temperature sensor

Abstract

Provided is a temperature sensor capable of reducing the heat released from a temperature-sensitive element. This temperature sensor comprises: a package that has one main surface facing one side in the thickness direction, a first other main surface facing the other side in the thickness direction, and a second other main surface facing the other side in the thickness direction; a temperature-sensitive element that is supported by the first other main surface; and a connection electrode that is provided to one of the second other main surface and the one main surface, and is electrically connected to the temperature-sensitive element. The distance in the thickness direction between the second other main surface and the one main surface is longer than the distance in the thickness direction between the first other main surface and the one main surface.

Description

Temperature Sensor

[0001] The present disclosure relates to a temperature sensor for detecting temperature.

[0002] Patent Document 1 discloses a sensor element as an example of a temperature sensor. The sensor element includes a carrier, an NTC thermistor as a temperature-sensing element disposed on the upper surface of the carrier, and an electrode disposed on the upper surface of the carrier. The electrode has a first region (bonding pad) and a second region (soldering pad). The NTC thermistor is soldered onto the second region (soldering pad). The sensor element is electrically connected to the outside by wire bonding the first electrode (bonding pad).

[0003] Patent No. 7394214

[0004] In order to maintain high temperature detection accuracy by a temperature sensor, it is desirable to minimize heat dissipation from the temperature sensor's thermosensitive element. However, in the temperature sensor disclosed in Patent Document 1, there is a risk of a large amount of heat dissipation from the NTC thermistor to the outside of the temperature sensor via the electrodes and wires. Furthermore, in the temperature sensor disclosed in Patent Document 1, the NTC thermistor is mounted on the top surface of the carrier, and the entire NTC thermistor protrudes from the top surface. Therefore, there is a risk of a large amount of heat dissipation from the NTC thermistor to the outside due to convection in the space around the NTC thermistor.

[0005] Therefore, an object of the present disclosure is to solve the above-mentioned problems by providing a temperature sensor that can reduce heat radiation from a temperature-sensitive element.

[0006] A temperature sensor according to one embodiment of the present disclosure comprises: a package having one main surface facing one side in a thickness direction, a first other main surface facing the other side in the thickness direction, and a second other main surface facing the other side in the thickness direction; an element mounting electrode provided on the first other main surface; a temperature sensing element supported on the first other main surface and electrically connected to the element mounting electrode; and a connection electrode provided on the second other main surface or the one main surface and electrically connected to the element mounting electrode, wherein the distance between the second other main surface and the one main surface in the thickness direction is longer than the distance between the first other main surface and the one main surface in the thickness direction.

[0007] According to the present disclosure, it is possible to provide a temperature sensor that can reduce heat radiation from a temperature sensitive element.

[0008] 2 is a side view showing a substrate, a heating element, and a temperature sensor according to a first embodiment of the present disclosure. FIG. 3 is a perspective view showing a temperature sensor according to a first embodiment of the present disclosure. FIG. 4 is a cross-sectional view showing a cross section taken along III-III in FIG. 2. FIG. 5 is a perspective view showing a modified example of a temperature sensor according to a first embodiment of the present disclosure. FIG. 6 is a perspective view showing a modified example of a temperature sensor according to a first embodiment of the present disclosure. FIG. 7 is a cross-sectional view showing a modified example of a temperature sensor according to a second embodiment of the present disclosure. FIG. 8 is a cross-sectional view showing a modified example of a temperature sensor according to a third embodiment of the present disclosure. FIG. 9 is a cross-sectional view showing a modified example of a temperature sensor according to a third embodiment of the present disclosure. FIG. 10 is a cross-sectional view showing a modified example of a temperature sensor according to a fourth embodiment of the present disclosure. FIG. 11 is a cross-sectional view showing a modified example of a temperature sensor according to a fourth embodiment of the present disclosure. FIG. 12 is a cross-sectional view showing a modified example of a temperature sensor according to a fourth embodiment of the present disclosure.

[0009] An example of the present disclosure will now be described with reference to the accompanying drawings. The following description is essentially illustrative and is not intended to limit the present disclosure, its applications, or its uses. The drawings are schematic, and the dimensional ratios and the like do not necessarily correspond to reality. In the following description, terms indicating specific directions or positions (e.g., terms including "upper," "lower," "right," "left," "front," and "rear") may be used as necessary. The present specification and drawings define the X, Y, and Z directions. The Z direction is the thickness direction of the temperature sensor, and the X and Y directions are directions perpendicular to the thickness direction of the temperature sensor. The X and Y directions intersect each other (orthogonal in the present specification and drawings). The Y direction is an example of an orthogonal direction. The use of the terms indicating specific directions or positions described above is intended to facilitate understanding of the present disclosure with reference to the drawings, and the meanings of these terms do not limit the technical scope of the present disclosure.

[0010] First Embodiment A temperature sensor is provided in a power module or the like provided in an electric vehicle or a household electrical appliance, for example.

[0011] FIG. 1 is a side view showing a substrate, a heating element, and a temperature sensor according to a first embodiment of the present disclosure. As shown in FIG. 1, a temperature sensor 10 is mounted on a substrate 2 included in a power module or the like. Note that the substrate 2 is depicted by a dashed line in all figures except FIG. 1. A heating element 4 is also mounted on the substrate 2. The heating element 4 is, for example, a semiconductor chip mounted on a power module. The temperature sensor 10 is mounted near the heating element 4. Most of the heat generated by the heating element 4 is transferred to the temperature sensor 10 via the substrate 2. The temperature sensor 10 detects the temperature of the heating element 4. The temperature sensor 10 outputs, for example, information regarding the temperature that changes in accordance with the temperature change of the heating element 4 to the outside via a wire 6 or the like. The information regarding the temperature of the heating element 4 is, for example, a current value or a voltage value within the temperature sensor 10.

[0012] Fig. 2 is a perspective view showing a temperature sensor according to the first embodiment of the present disclosure. Fig. 3 is a cross-sectional view showing a cross section taken along line III-III in Fig. 2. Note that the cross-sectional views of Figs. 8 to 14, which will be described later, show cross sections corresponding to the cross section taken along line III-III in Fig. 2.

[0013] As shown in FIGS. 2 and 3 , the temperature sensor 10 includes a package 20 , a temperature sensitive element 30 , connection electrodes 40 , and mounting electrodes 50 .

[0014] In the first embodiment, the package 20 is made of an insulating material such as ceramic or glass epoxy. Examples of ceramic include alumina, silicon nitride, and aluminum nitride. Silicon dioxide, magnesium oxide, and the like may be added to alumina. Note that the material of the package 20 is not limited to the ceramic and glass epoxy described above.

[0015] As shown in FIG. 3, the package 20 has one main surface 20A facing one side in the Z direction, and a first other main surface 20B and a second other main surface 20C facing the other side in the Z direction.

[0016] A distance D1 between the second other principal surface 20C and the one principal surface 20A in the Z direction is longer than a distance D2 between the first other principal surface 20B and the one principal surface 20A in the Z direction.

[0017] 2 and 3, the package 20 has a recess 20E. The recess 20E is recessed in the Z direction from the second other principal surface 20C toward the one principal surface 20A. The recess 20E has a first other principal surface 20B and an inner side surface 20D. The first other principal surface 20B is the bottom surface of the recess 20E. The inner side surface 20D is a side surface of the recess 20E and connects the first other principal surface 20B and the second other principal surface 20C.

[0018] 2, both Y-direction ends of the recess 20E are open in the Y direction. In other words, the recess 20E extends from one Y-direction end to the other Y-direction end of the package 20, and has an opening 20Ea at one Y-direction end and an opening 20Eb at the other Y-direction end. This divides the second other main surface 20C into two regions with the recess 20E in between.

[0019] The recess 20E is formed by various known manufacturing methods. For example, the recess 20E may be formed by stacking multiple sheets. More specifically, the package 20 is manufactured by stacking a second sheet having a second other principal surface 20C on a first other principal surface 20B of a first sheet having a first principal surface 20A and a first other principal surface 20B. When the second sheet is stacked on the first sheet, the second sheet is stacked on a portion of the first sheet excluding the recess 20E. This forms the recess 20E. Alternatively, for example, the recess 20E may be formed by performing countersinking, sandblasting, polishing, or the like on the surface of the package 20.

[0020] Pads 21 and 22 are provided on the first other principal surface 20B as element mounting electrodes. A connection electrode 40 having a first connection electrode 41 and a second connection electrode 42 is provided on the second other principal surface 20C. A mounting electrode 50 is provided on the one principal surface 20A. That is, the mounting electrode 50 is provided on the opposite side of the first other principal surface 20B from the one principal surface 20A in the Z direction. Wiring patterns 23 and 24 are provided across the first other principal surface 20B, the inner side surface 20D, and the second other principal surface 20C.

[0021] The pads 21, 22, connection electrodes 40, mounting electrodes 50, and wiring patterns 23, 24 are formed on the surface of the package 20 by baking, plating, sputtering, or the like, of a conductive material. Examples of the conductive material include silver (Ag), molybdenum (Mo), copper (Cu), and titanium (Ti). An electrode surface layer may be formed to cover the conductive material. The electrode surface layer may have, for example, a three-layer structure of nickel (Ni), palladium (Pd), and gold (Au), or a single-layer structure of tin (Sn).

[0022] The connection electrode 40 is an electrode for extracting the characteristics from the temperature sensitive element 30. The characteristics of the temperature sensitive element 30 are, for example, a current value that varies depending on the temperature of the temperature sensitive element 30. In other words, the characteristics of the temperature sensitive element 30 correspond to information related to temperature that changes with changes in the temperature of the heating element 4.

[0023] In the first embodiment, the temperature sensor 10 has a first connection electrode 41 and a second connection electrode 42 as the connection electrodes 40. The first connection electrode 41 is provided in one of two regions on the second other principal surface 20C. The second connection electrode 42 is provided in the other of the two regions on the second other principal surface 20C.

[0024] The first connection electrode 41 is electrically connected to the pad 21 via the wiring pattern 23. The second connection electrode 42 is electrically connected to the pad 22 via the wiring pattern 24. Note that the electrical connection between the first connection electrode 41 and the pad 21 is not limited to being via the wiring pattern 23, and the electrical connection between the second connection electrode 42 and the pad 22 is not limited to being via the wiring pattern 24. For example, the first connection electrode 41 and the second connection electrode 42 may be electrically connected to the pads 21 and 22 via via conductors provided inside the package 20 along the Z direction.

[0025] Each of the first connection electrode 41 and the second connection electrode 42 is electrically connected to the outside of the temperature sensor 10 via a wire 6 (see FIG. 1 ). Although one wire 6 is shown in FIG. 1 , in reality, a different wire 6 is connected to each of the first connection electrode 41 and the second connection electrode 42. In other words, two wires 6 are connected to the temperature sensor 10.

[0026] In the first embodiment, the temperature sensor 10 has two connection electrodes 40 on the second other principal surface 20C, but the number of connection electrodes 40 provided on the second other principal surface 20C is not limited to two. For example, the temperature sensor 10 may have only one connection electrode 40 on the second other principal surface 20C. In this case, the other connection electrodes 40 except for the one connection electrode 40 may be provided on a side surface of the package 20 or on the first other principal surface 20B, for example.

[0027] The mounting electrode 50 is used to mount the temperature sensor 10 on the substrate 2 (see FIG. 1 ) by sintering. For example, if the mounting electrode 50 is made of silver (Ag), the temperature sensor 10 is joined to the substrate 2 by sintering a sintering paste made of this silver (Ag) at a high temperature. That is, in the first embodiment, one main surface 20A of the temperature sensor 10 is joined to the substrate 2 via the mounting electrode 50.

[0028] The means for joining the temperature sensor 10 to the substrate 2 is not limited to sintering, and other known means such as solder reflow may also be used. The temperature sensor 10 does not have to have the mounting electrodes 50. In this case, the temperature sensor 10 is joined to the substrate 2 by known means such as an adhesive.

[0029] The mounting electrode 50 is electrically insulated from the temperature sensitive element 30 and the connection electrode 40 .

[0030] The temperature sensing element 30 is mounted on the first other principal surface 20B of the package 20. In other words, the temperature sensing element 30 is supported on the first other principal surface 20B. In the first embodiment, the temperature sensing element 30 is a surface-mounted thermistor element. In the first embodiment, the temperature sensing element 30 has two element electrodes 31, 32. One of the two element electrodes 31, 32 is a positive electrode, and the other of the two element electrodes 31, 32 is a negative electrode.

[0031] The two element electrodes 31, 32 are formed on the surface of the temperature sensing element 30 by baking, plating, sputtering, or the like of a conductive material. Examples of the conductive material include silver (Ag), silver-palladium (AgPd), copper (Cu), etc. Note that, like the conductive material of the pads 21, 22, etc., an electrode surface layer may be formed so as to cover the element electrodes 31, 32.

[0032] One of the element electrodes 31, 32 is metal-bonded to the pad 21 via a bonding material 33 such as solder or a conductive adhesive, and the other of the element electrodes 31, 32 is metal-bonded to the pad 22 via a bonding material 34 such as solder or a conductive adhesive. In other words, the temperature sensing element 30 is electrically connected to the pads 21, 22.

[0033] As a result, the temperature sensing element 30 is electrically connected to the first connection electrode 41 via the pad 21 and the wiring pattern 23 , and is electrically connected to the second connection electrode 42 via the pad 22 and the wiring pattern 24 .

[0034] As a result, the current flowing through the temperature sensor 30 is output from the connection electrode 40 via the wire 6 (see FIG. 1) to the outside of the temperature sensor 10. The temperature inside the temperature sensor 30 is detected according to the value of this current. For example, if the temperature sensor 30 is an NTC thermistor (negative temperature coefficient thermistor), the resistance of the temperature sensor 30 decreases as the temperature inside the temperature sensor 30 increases, resulting in a higher current being output to the outside. When the temperature inside the temperature sensor 30 increases due to the heat generated by the heating element 4 (see FIG. 1) being transferred to the temperature sensor 30 of the temperature sensor 10, the current output to the outside of the temperature sensor 10 increases.

[0035] When the temperature-sensing element 30 is a thermistor element, the temperature-sensing element 30 is not limited to an NTC thermistor, but may be, for example, a PTC thermistor (positive temperature coefficient thermistor). The temperature-sensing element 30 is not limited to a thermistor element as long as it is an element that can detect temperature by changing its characteristics in response to temperature. For example, the temperature-sensing element 30 may be a platinum-side temperature resistor (a so-called Pt sensor).

[0036] As shown in Figure 3, the distance D3 between the first other principal surface 20B and the second other principal surface 20C in the Z direction is equal to or greater than the length L1 of the temperature sensing element 30 in the Z direction. In the configuration shown in Figure 3, the distance D3 is greater than the length L1. In the configuration shown in Figure 3, the temperature sensing element 30 does not protrude in the Z direction relative to the second other principal surface 20C. In other words, the entire temperature sensing element 30 is located within the recess 20E. Note that the distance D3 may be less than the length L1. In other words, a portion of the temperature sensing element 30 may protrude in the Z direction relative to the second other principal surface 20C.

[0037] A distance D3 between the first other principal surface 20B and the second other principal surface 20C in the Z direction is longer than the shortest distance D4 between the temperature sensing element 30 and the outer edge of the first other principal surface 20B when viewed along the Z direction.

[0038] <Modifications of First Embodiment> FIGS. 4, 5, 6, and 7 are perspective views showing modifications of the temperature sensor according to the first embodiment of the present disclosure.

[0039] In the configuration shown in Fig. 2, the pads 21 and 22 are arranged side by side in the Y direction, but the positions at which the pads 21 and 22 are arranged are not limited to the positions shown in Fig. 2. For example, as shown in Fig. 4, the pads 21 and 22 may be arranged side by side in the X direction. The orientation of the temperature sensing element 30 is determined depending on the positions at which the pads 21 and 22 are arranged.

[0040] In the configuration shown in FIG. 2 , both Y-direction ends of the recess 20E are open in the Y direction, but this configuration is not limited thereto. For example, only one Y-direction end of the recess 20E may be open in the Y direction. Furthermore, for example, at least one of both X-direction ends of the recess 20E may be open in the X direction. Furthermore, for example, as shown in FIG. 5 , the recess 20E does not have to be open in a direction perpendicular to the Z direction (e.g., the X direction and the Y direction). In other words, the entire periphery of the first other major surface 20B may be surrounded by the second other major surface 20C when viewed along the Z direction.

[0041] In the configurations shown in Figures 2 and 3, the temperature sensor 30 is a surface-mount type, but the temperature sensor 30 is not limited to a surface-mount type. For example, as shown in Figure 6, the temperature sensor 30 may be a bare-chip mounted type. Figure 6 shows a wire-bonded configuration of bare-chip mounting. That is, in Figure 6, the temperature sensor 30 is electrically connected to the pad 22 via a wire 8. Note that the temperature sensor 30 may also be mounted on the package 20 by bare-chip mounting other than wire bonding, such as tape automated bonding (TAB) or flip chip mounting.

[0042] 7, the package 20 may have a step. The surface below the step is the first other principal surface 20B, and the surface above the step is the second other principal surface 20C. The package 20 shown in FIG. 7 can also be regarded as having a recessed portion that is open at both ends in the Y direction and one end in the X direction, and whose bottom is the first other principal surface 20B.

[0043] The temperature sensor 10 according to the first embodiment can achieve the following effects.

[0044] According to the first embodiment, the first other principal surface 20B supporting the temperature sensitive element 30 and the second other principal surface 20C on which the connection electrode 40 is provided are at different positions in the Z direction. This creates a temperature gradient between the first other principal surface 20B and the second other principal surface 20C, reducing the transfer of heat from the first other principal surface 20B to the second other principal surface 20C. As a result, heat dissipation from the temperature sensitive element 30 to the connection electrode 40 can be reduced.

[0045] According to the first embodiment, the first other principal surface 20B supporting the temperature sensing element 30 is located lower than the second other principal surface 20C in the Z direction. Therefore, the second other principal surface 20C reduces convection in the space around the temperature sensing element 30. As a result, heat radiation from the temperature sensing element 30 can be reduced.

[0046] According to the first embodiment, the entire temperature sensing element 30 is located lower than the second other principal surface 20C in the Z direction. Therefore, convection in the space around the temperature sensing element 30 is reduced by the second other principal surface 20C compared to a configuration in which a part of the temperature sensing element 30 is located higher than the second other principal surface 20C in the Z direction, in other words, a configuration in which the length L1 is longer than the distance D3.

[0047] When the temperature sensor 10 is mounted on the substrate 2 by silver sintering, the temperature sensor 10 is subjected to a high-temperature pressure treatment. Here, if the distance D3 between the first other principal surface 20B and the second other principal surface 20C in the Z direction of the temperature sensor is less than the length L1 of the temperature sensor 30 in the Z direction, a portion of the temperature sensor 30 protrudes in the Z direction relative to the second other principal surface 20C. When the pressure treatment described above is performed on a temperature sensor with such a configuration, external loads may be concentrated on the protruding temperature sensor 30. Furthermore, in this case, it is difficult to apply the external load uniformly across the entire surface of the one principal surface 20A, which is the mounting surface of the temperature sensor on the substrate 2. This makes it difficult to form a uniform sintered layer, potentially reducing the reliability of the bond between the temperature sensor and the substrate 2.

[0048] According to the first embodiment, the distance D3 between the first other principal surface 20B and the second other principal surface 20C in the Z direction is equal to or greater than the length L1 of the temperature sensor 30 in the Z direction. This reduces the likelihood of the aforementioned problems occurring. In other words, when the temperature sensor 10 of the first embodiment is subjected to the aforementioned pressurization treatment, an external load can be applied to the second other principal surface 20C instead of or in addition to the temperature sensor 30. This prevents the external load from concentrating on the temperature sensor 30. Furthermore, in this case, compared to a configuration in which the distance D3 is less than the length L1, it is easier to apply the external load uniformly across the entire one principal surface 20A. This facilitates the formation of a uniform sintered layer, thereby facilitating the maintenance of high bonding reliability between the temperature sensor 10 and the substrate 2.

[0049] According to the first embodiment, since the temperature sensing element 30 is located within the recess 20E, it is possible to reduce heat transfer from the temperature sensing element 30 to the connection electrode 40 located outside the recess 20E. Furthermore, since the temperature sensing element 30 is located within the recess 20E, convection in the space around the temperature sensing element 30 is reduced compared to a configuration in which the temperature sensing element 30 is located outside the recess 20E. As a result, it is possible to reduce heat dissipation from the temperature sensing element 30.

[0050] 5 and 6, the entire periphery of the first other principal surface 20B is surrounded by the second other principal surface 20C when viewed along the Z direction. In this case, air is more likely to remain in the recess 20E than in a configuration in which only a portion of the first other principal surface 20B is surrounded by the second other principal surface 20C when viewed along the Z direction (in other words, a configuration in which the recess 20E is not open in a direction perpendicular to the Z direction). This reduces convection in the space around the temperature sensing element 30. As a result, heat radiation from the temperature sensing element 30 can be reduced.

[0051] 2, 3, 4, and 7, at least one of both ends of the recess 20E is open in the orthogonal direction, which makes it easier to simplify the manufacturing process of the package 20 and reduce the cost of the package 20 compared to a configuration in which the recess 20E is not open in the orthogonal direction.

[0052] According to the first embodiment, the distance D3 between the first other principal surface 20B and the second other principal surface 20C in the Z direction is longer than the shortest distance D4 between the temperature sensor 30 and the outer edge of the first other principal surface 20B when viewed along the Z direction. This increases the distance between the temperature sensor 30 and the connection electrode 40 in the Z direction, thereby reducing heat dissipation from the temperature sensor 30 to the connection electrode 40.

[0053] Second Embodiment Fig. 8 is a cross-sectional view showing a temperature sensor according to a second embodiment of the present disclosure. The temperature sensor 10A according to the second embodiment differs from the temperature sensor 10 according to the first embodiment in that the package 20 is made up of multiple parts made of different materials. Differences from the first embodiment will be described below. Components in common with the temperature sensor 10 according to the first embodiment are denoted by the same reference numerals, and their description will be omitted in principle, and will be described only when necessary.

[0054] As shown in Figure 8, the package 20 includes a first package 25 and a second package 26. The first package 25 has one main surface 20A and a first other main surface 20B. The second package 26 is stacked on the side of the first package 25 opposite the one main surface 20A. The second package 26 is stacked on a portion of the first other main surface 20B. The portion of the first other main surface 20B on which the second package 26 is not stacked is exposed to the outside of the temperature sensor 10. This exposed portion is the bottom surface of the recess 20E, and the temperature sensing element 30 is mounted in this portion.

[0055] The second package 26 has a second other principal surface 20 C. The second other principal surface 20 C is a surface of the surface of the second package 26 that is located on the opposite side to the first package 25 in the Z direction.

[0056] The first package 25 and the second package 26 are made of different materials.

[0057] In the second embodiment, the first package 25 is made of an insulating material such as ceramic or glass epoxy, as in the first embodiment. On the other hand, the second package 26 contains a conductive material such as copper or aluminum. Note that the entire second package 26 may be made of a conductive material, or only a portion of the second package 26 may be made of a conductive material.

[0058] Conversely, the first package 25 may contain a conductive material while the second package 26 may be made of an insulating material. Alternatively, both the first package 25 and the second package 26 may contain a conductive material. Alternatively, neither the first package 25 nor the second package 26 may contain a conductive material.

[0059] 8, the first portion of the second package 26, where the first connection electrode 41 is provided, and the second portion of the second package 26, where the second connection electrode 42 is provided, are separated by the recess 20E and are therefore electrically insulated from each other. Similarly, even in the case where the first connection electrode 41 and the second connection electrode 42 are provided in the second package 26 made of a conductive material in the configurations shown in FIGS. 3 and 4, the first portion and the second portion are electrically insulated from each other.

[0060] However, when the first connection electrode 41 and the second connection electrode 42 are provided on the second package 26 made of a conductive material in the configurations shown in Figures 5, 6, and 7, the first and second portions are electrically connected to each other. Therefore, when the first connection electrode 41 and the second connection electrode 42 are provided on the second package 26 made of a conductive material in the configurations shown in Figures 5, 6, and 7, the first and second portions of the second package 26 are configured to be separated from each other.

[0061] In the second embodiment shown in Figure 8, of the first package 25 and the second package 26, the second package 26 that has the connection electrode 40 has a lower thermal conductivity than the first package 25 that does not have the connection electrode 40.

[0062] For example, the second package 26 is made of iron (Fe), which is a conductive material, while the first package 25 is made of silicon (Si), which is an insulating material and has a higher thermal conductivity than iron. Of course, the materials of the first package 25 and the second package 26 are not limited to the above materials (iron and silicon).

[0063] Conversely, the first package 25, which does not have the connection electrodes 40, may have a lower thermal conductivity than the second package 26, which has the connection electrodes 40. Alternatively, the first package 25 and the second package 26 may have the same thermal conductivity.

[0064] <Modification of Second Embodiment> FIG. 9 is a cross-sectional view showing a modification of the temperature sensor according to the second embodiment of the present disclosure.

[0065] In the configuration shown in Fig. 8, the outer edge 25A of the first package 25 and the outer edge 26A of the second package 26 are at the same position when viewed along the Z direction. In other words, the outer surface of the first package 25 and the outer surface of the second package 26 are flush with each other. However, when viewed along the Z direction, the outer edge 25A of the first package 25 and the outer edge 26A of the second package 26 may be at different positions. For example, as shown in Fig. 9, when viewed along the Z direction, the outer edge 26A of the second package 26 may be located more inward than the outer edge 25A of the first package 25.

[0066] Note that a similar configuration may be used in other embodiments besides Embodiment 2. For example, in the configuration shown in Fig. 3, the outer surface of the portion of the package 20 between the one main surface 20A and the first other main surface 20B in the Z direction and the outer surface of the portion of the package 20 between the first other main surface 20B and the second other main surface 20C in the Z direction do not need to be flush with each other.

[0067] 8 and 9, the package 20 has a two-layer structure (i.e., a structure consisting of a first package 25 and a second package 26) stacked in the Z direction. However, the package 20 may have a three-layer or more layer structure. In this case, one layer of the package consisting of three or more layers may correspond to the first package, and another layer may correspond to the second package.

[0068] According to the second embodiment, the materials of the first package 25 and the second package 26 can be selected to be suitable for achieving the purpose of each package. For example, the material of the first package 25 can be selected to be suitable for mounting the temperature sensitive device 30. Furthermore, for example, when the connection electrode 40 is provided in the second package 26, the material of the second package 26 can be selected to be suitable for forming the connection electrode 40.

[0069] The temperature sensing element 30 and the connection electrode 40 are electrically connected to each other, for example, via a wiring pattern. For example, when the connection electrode 40 is provided on the second other principal surface 20C, the temperature sensing element 30 and the connection electrode 40 are electrically connected to each other via wiring patterns 23, 24 provided across the first other principal surface 20B, the inner surface 20D, and the second other principal surface 20C.

[0070] In contrast, according to the second embodiment, the second package 26 on which the connection electrode 40 is provided contains a conductive material. Therefore, according to the second embodiment, the temperature sensing element 30 and the connection electrode 40 can be electrically connected to each other via the second package 26. In other words, according to the second embodiment, the wiring patterns 23, 24 do not need to be provided across the first other principal surface 20B, the inner side surface 20D, and the second other principal surface 20C, but only need to be provided on the first other principal surface 20B between the temperature sensing element 30 and the second package 26. This allows the wiring patterns 23, 24 for electrically connecting the temperature sensing element 30 and the connection electrode 40 to be shortened.

[0071] Furthermore, for example, if the temperature sensitive element 30 is configured to contact the second package 26 provided with the connection electrodes 40, the temperature sensitive element 30 and the connection electrodes 40 can be electrically connected without going through the wiring patterns 23, 24. In other words, the wiring patterns for electrically connecting the temperature sensitive element 30 and the connection electrodes 40 can be eliminated.

[0072] Furthermore, for example, as in a modified example of the third embodiment described later (see FIG. 11 ), when the connection electrode 40 is provided on one main surface 20A, the temperature sensing element 30 and the connection electrode 40 are electrically connected to each other through via conductors (not shown) that penetrate the first package 25 in the Z direction. However, even in this case, by making the first package 25 out of a conductive material, electrical connection can be achieved via the first package 25 itself instead of the via conductors, making the via conductors unnecessary.

[0073] Heat generated in the temperature sensitive element 30 is conducted to the connection electrode 40 via the package in which the connection electrode 40 is provided (the second package 26 in the second embodiment) of the first package 25 and the second package 26. According to the second embodiment, the thermal conductivity of the second package 26 in which the connection electrode 40 is provided is lower than the thermal conductivity of the first package 25, so that heat dissipation from the temperature sensitive element 30 to the connection electrode 40 can be reduced.

[0074] 10 is a cross-sectional view showing a temperature sensor according to a third embodiment of the present disclosure. The temperature sensor 10B according to the third embodiment differs from the temperature sensor 10 according to the first embodiment in that the connection electrode 40 is provided on the first principal surface 20A and the mounting electrode 50 is provided on the second principal surface 20C. The differences from the first embodiment will be described below. The same reference numerals are used to denote commonalities with the temperature sensor 10 according to the first embodiment, and explanations thereof will be omitted in principle and will be provided only when necessary.

[0075] 10 , in the temperature sensor 10B, the connection electrode 40 is provided on the one principal surface 20A, and the mounting electrode 50 is provided on the second other principal surface 20C. In other words, the mounting electrode 50 is provided on the opposite side of the first other principal surface 20B from the second other principal surface 20C in the Z direction.

[0076] In the third embodiment, the second other principal surface 20C of the temperature sensor 10B is joined to the substrate 2 via the mounting electrode 50. As a result, when the temperature sensor 10B is mounted on the substrate 2, the opening of the recess 20E in the Z direction is blocked by the substrate 2. Note that in the configuration shown in Fig. 10, when the temperature sensor 10B is mounted on the substrate 2, the openings at both ends of the recess 20E in the Y direction are not blocked by the substrate 2 but are open. In other words, in this case, part of the exposed portion of the temperature sensing element 30 is covered by the substrate 2.

[0077] 5 and 6 , when the connection electrode 40 is provided on the one principal surface 20A and the mounting electrode 50 is provided on the second other principal surface 20C, the recess 20E closed by the substrate 2 is sealed. That is, in this case, the entire exposed portion of the temperature sensing element 30 is covered by the substrate 2.

[0078] 11 is a cross-sectional view showing a modification of the temperature sensor according to the third embodiment of the present disclosure. As shown in FIG. 11 , in the temperature sensor 10B according to the third embodiment, the package 20 may include a first package 25 and a second package 26, similar to the temperature sensor 10 according to the first embodiment.

[0079] According to the third embodiment, the first other principal surface 20B supporting the temperature sensitive element 30 and the one principal surface 20A on which the connection electrode 40 is provided are at different positions in the Z direction. This creates a temperature gradient between the first other principal surface 20B and the one principal surface 20A, making it possible to reduce heat transfer from the first other principal surface 20B to the one principal surface 20A. As a result, it is possible to reduce heat dissipation from the temperature sensitive element 30 to the connection electrode 40.

[0080] According to the third embodiment, when the temperature sensor 10B is mounted on the substrate 2 via the mounting electrodes 50, at least a portion of the exposed portion of the temperature sensing element 30 can be covered by the substrate 2. This reduces convection in the space around the temperature sensing element 30. As a result, heat radiation from the temperature sensing element 30 can be reduced.

[0081] <Fourth embodiment> Figure 12 is a cross-sectional view showing a temperature sensor according to a fourth embodiment of the present disclosure. The temperature sensor 10C according to the fourth embodiment differs from the temperature sensor 10 according to the first embodiment in that it includes a covering member 60 that is provided on at least the first other principal surface 20B and covers the temperature sensing element 30. Differences from the first embodiment will be described below. Components in common with the temperature sensor 10 according to the first embodiment are denoted by the same reference numerals, and their description will be omitted in principle, and will be described only when necessary.

[0082] 12, the temperature sensor 10C includes a covering member 60 filled in the recess 20E. The covering member 60 is provided on the first other principal surface 20B and covers the temperature sensing element 30. The covering member 60 is made of, for example, a urethane-based, acrylic-based, or epoxy-based resin, but is not limited to, resin. For example, the covering member 60 may be a glass, olefin-based, or fluorine-based coating material that is applied to the surface of the temperature sensing element 30.

[0083] The covering member 60 has a contact surface 60A in contact with the first other principal surface 20B in the Z direction, and an opposite surface 60B that is provided on the opposite side of the one principal surface 20A relative to the contact surface 60A in the Z direction and faces away from the contact surface 60A in the Z direction. In the configuration shown in Fig. 12, a distance D5 between the opposite surface 60B and the first other principal surface 20B is smaller than a distance D3 between the first other principal surface 20B and the second other principal surface 20C in the Z direction.

[0084] <Modification of the Fourth Embodiment> In the configuration shown in Fig. 12, the covering member 60 is provided only in the vicinity of the temperature sensitive element 30. However, the covering member 60 may be provided not only in the vicinity of the temperature sensitive element 30 but also in other areas. In other words, the covering member 60 may be provided over a wide area. By providing the covering member 60 over a wide area, the volume of the covering member 60 increases, making it possible to reinforce the package 20. In addition, it becomes easier to control the amount of covering member 60 applied.

[0085] 13 is a cross-sectional view showing a modified example of the temperature sensor according to the fourth embodiment of the present disclosure. In the configuration shown in Fig. 13, the covering member 60 is provided not only inside the recess 20E but also outside the recess 20E.

[0086] 12 and 13 , the distance D5 between the opposite surface 60B and the first other principal surface 20B is smaller than the distance D3 between the first other principal surface 20B and the second other principal surface 20C in the Z direction. In other words, the covering member 60 does not protrude from the second other principal surface 20C. However, the distance D5 may be greater than or equal to the distance D3. When the distance D5 and the distance D3 are the same, the opposite surface 60B and the second other principal surface 20C can be flush with each other. Furthermore, when the distance D5 is greater than the distance D3, the covering member 60 can protrude from the second other principal surface 20C.

[0087] FIG. 14 is a cross-sectional view showing a modified example of the temperature sensor according to the fourth embodiment of the present disclosure. In the configuration shown in FIG. 14 , the distance D5 is greater than the distance D3, and the opposite surface 60B is located on the opposite side of the first other principal surface 20B from the second other principal surface 20C in the Z direction. Also, in the configuration shown in FIG. 14 , similar to the configuration shown in FIG. 10 , the connection electrode 40 is provided on the one principal surface 20A, and the mounting electrode 50 is provided on the opposite side of the first other principal surface 20B from the second other principal surface 20C in the Z direction. In the configuration shown in FIG. 14 , the mounting electrode 50 is provided on the opposite surface 60B, not on the second other principal surface 20C. In other words, in the configuration shown in FIG. 14 , the opposite surface 60B of the covering member 60 of the temperature sensor 10C is joined to the substrate 2 via the mounting electrode 50.

[0088] According to the fourth embodiment, the strength of the temperature sensor 10C can be increased by the covering member 60.

[0089] 14, when the temperature sensor 10C is mounted on the substrate 2 with the first other principal surface 20B and the substrate 2 facing each other in the Z direction via the covering member 60, heat from the substrate 2 is transferred to the temperature sensing element 30 via the covering member 60. Therefore, in the configuration shown in Fig. 14, the efficiency of heat dissipation from the substrate 2 to the temperature sensing element 30 can be increased compared to a configuration in which the temperature sensing element 30 and the substrate 2 face each other via air, and therefore heat from the substrate 2 is transferred to the temperature sensing element 30 via air.

[0090] The temperatures described above can also be expressed as follows:

[0091] (1) A temperature sensor according to one aspect of the present disclosure comprises: a package having one main surface facing one side in a thickness direction, a first other main surface facing the other side in the thickness direction, and a second other main surface facing the other side in the thickness direction; an element mounting electrode provided on the first other main surface; a temperature sensing element supported on the first other main surface and electrically connected to the element mounting electrode; and a connection electrode provided on the second other main surface or the one main surface and electrically connected to the element mounting electrode, wherein the distance between the second other main surface and the one main surface in the thickness direction is longer than the distance between the first other main surface and the one main surface in the thickness direction.

[0092] (2) In the temperature sensor of (1), a distance between the first other principal surface and the second other principal surface in the thickness direction may be equal to or greater than a length of the temperature sensitive element in the thickness direction.

[0093] (3) In the temperature sensor of (1) or (2), the package may have a recess recessed in the thickness direction relative to the second other principal surface, and the first other principal surface may be a bottom surface of the recess.

[0094] (4) In the temperature sensor of (3), the first other principal surface may be entirely surrounded by the second other principal surface when viewed along the thickness direction.

[0095] (5) In the temperature sensor of (3), at least one end of the recess may be open in a direction perpendicular to the thickness direction.

[0096] (6) In the temperature sensor of any one of (1) to (5), the package may include: a first package having the one main surface and the first other main surface; and a second package stacked on the side of the first package opposite the one main surface, made of a different material from the first package, and having the second other main surface.

[0097] (7) In the temperature sensor of (6), the package provided with the connection electrodes out of the first package and the second package may include a conductive material.

[0098] (8) In the temperature sensor of (6) or (7), the package of the first package and the second package on which the connection electrode is provided may have a lower thermal conductivity than the package of the first package and the second package on which the connection electrode is not provided.

[0099] (9) Any one of the temperature sensors (1) to (8) may further include a mounting electrode that is provided on the opposite side of the first other principal surface relative to the one principal surface in the thickness direction and is electrically insulated from the temperature-sensing element and the connection electrode, and the connection electrode may be provided on the second other principal surface.

[0100] (10) Any one of the temperature sensors (1) to (8) may further include a mounting electrode that is provided on the opposite side of the first other principal surface relative to the second other principal surface in the thickness direction and is electrically insulated from the temperature-sensing element and the connection electrode, and the connection electrode may be provided on the one principal surface.

[0101] (11) In any one of the temperature sensors (1) to (10), the distance between the second other principal surface and the first other principal surface in the thickness direction may be longer than the shortest distance between the temperature sensing element and the outer edge of the first other principal surface when viewed along the thickness direction.

[0102] (12) The temperature sensor according to any one of (1) to (11) may further include a covering member provided on at least the first other principal surface and covering the temperature sensitive element.

[0103] (13) In the temperature sensor of (12), the covering member may have a contact surface in contact with the first other principal surface in the thickness direction, and an opposite surface provided on the opposite side of the one principal surface relative to the contact surface in the thickness direction and facing away from the contact surface in the thickness direction, and the distance between the opposite surface and the first other principal surface in the thickness direction may be equal to or greater than the distance between the second other principal surface and the first other principal surface in the thickness direction.

[0104] Any of the various embodiments described above may be combined appropriately to achieve the effects of each of them.

[0105] While the present invention has been fully described in connection with preferred embodiments, with appropriate reference to the drawings, various changes and modifications will become apparent to those skilled in the art, and it is to be understood that such changes and modifications are included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

[0106] 10 Temperature sensor 20 Package 20A One main surface 20B First other main surface 20C Second other main surface 20E Recess 25 First package 26 Second package 30 Temperature sensing element 40 Connection electrode 50 Mounting electrode 60 Covering member 60A Contact surface 60B Opposite surface

Claims

1. A temperature sensor comprising: a package having one main surface facing one side in a thickness direction, a first other main surface facing the other side in the thickness direction, and a second other main surface facing the other side in the thickness direction; an element mounting electrode provided on the first other main surface; a temperature sensing element supported on the first other main surface and electrically connected to the element mounting electrode; and a connection electrode provided on the second other main surface or the one main surface and electrically connected to the element mounting electrode, wherein the distance between the second other main surface and the one main surface in the thickness direction is longer than the distance between the first other main surface and the one main surface in the thickness direction.

2. The temperature sensor according to claim 1, wherein the distance between the first other principal surface and the second other principal surface in the thickness direction is equal to or greater than the length of the temperature sensitive element in the thickness direction.

3. A temperature sensor according to claim 1 or 2, wherein the package has a recess recessed in the thickness direction relative to the second other principal surface, and the first other principal surface is the bottom surface of the recess.

4. The temperature sensor according to claim 3, wherein the first other principal surface is entirely surrounded by the second other principal surface when viewed along the thickness direction.

5. The temperature sensor according to claim 3, wherein at least one end of the recess is open in a direction perpendicular to the thickness direction.

6. A temperature sensor according to any one of claims 1 to 5, wherein the package comprises: a first package having the one main surface and the first other main surface; and a second package stacked on the side of the first package opposite the one main surface, made of a different material from the first package, and having the second other main surface.

7. The temperature sensor according to claim 6, wherein one of the first package and the second package on which the connection electrodes are provided contains a conductive material.

8. A temperature sensor as described in claim 6 or 7, wherein the package of the first package and the second package that is provided with the connection electrodes has a lower thermal conductivity than the package of the first package and the second package that is not provided with the connection electrodes.

9. A temperature sensor as described in any one of claims 1 to 8, further comprising a mounting electrode provided on the opposite side of the first other principal surface from the one principal surface in the thickness direction, the mounting electrode being electrically insulated from the temperature sensing element and the connection electrode, the connection electrode being provided on the second other principal surface.

10. A temperature sensor as described in any one of claims 1 to 8, further comprising a mounting electrode provided on the opposite side of the first other principal surface in the thickness direction from the second other principal surface, the mounting electrode being electrically insulated from the temperature sensing element and the connection electrode, the connection electrode being provided on the one principal surface.

11. A temperature sensor described in any one of claims 1 to 10, wherein the distance between the second other principal surface and the first other principal surface in the thickness direction is longer than the shortest distance between the temperature-sensing element and the outer edge of the first other principal surface when viewed along the thickness direction.

12. A temperature sensor according to any one of claims 1 to 11, further comprising a covering member provided on at least the first other principal surface to cover the temperature sensitive element.

13. A temperature sensor as described in claim 12, wherein the covering member has a contact surface in contact with the first other principal surface in the thickness direction, and an opposite surface provided on the opposite side of the one principal surface relative to the contact surface in the thickness direction and facing away from the contact surface in the thickness direction, and the distance between the opposite surface and the first other principal surface in the thickness direction is equal to or greater than the distance between the second other principal surface and the first other principal surface in the thickness direction.

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