Temperature sensor and temperature sensing structure

Abstract

Provided are: a thin film type temperature sensor in which a heat-sensitive thin film is formed on a part of the front surface of a substrate, and which has good responsiveness, can also provide accurate temperature measurement, and is particularly suitable for application to surface-mounted devices; and a temperature sensing structure employing the same.　In the temperature sensor, a heat-sensitive thin film is formed on a part of the front surface of a substrate. The temperature sensor includes an electrode set, the set comprising a pair of front surface electrodes and a pair of rear surface electrodes that are formed respectively on the front surface and the rear surface of the substrate and that oppose one another across the substrate at the periphery of the heat-sensitive thin film, pass-through electrodes that electrically connect the front surface electrodes and the rear surface electrodes, and connecting electrodes that are formed on the front surface and that electrically connect the heat-sensitive thin film and the front surface electrodes, wherein the heat-sensitive thin film and the connecting electrodes are formed such that the heights thereof are equal to or less than the height of the front surface electrodes in a heat-sensitive portion region of the front surface including, on the inside of said region, at least the front surface electrodes, the heat-sensitive thin film, and the connecting electrodes. Furthermore, in the temperature sensing structure, the temperature sensor is interposed between a main substrate and an electronic component.

Description

Temperature Sensor and Temperature Sensing Structure

[0001] The present invention relates to a temperature sensor having a heat-sensitive thin film formed on a part of the surface of a substrate and a temperature sensing structure using the same.

[0002] Among surface-mounted devices (SMDs) in which electronic components such as semiconductors are surface-mounted on a printed circuit board (PCB), those that measure the internal temperature and ambient temperature and detect abnormalities thereof, and those that have a temperature sensor installed for temperature compensation of electronic components are known (for example, Patent Document 1).

[0003] Here, for the temperature sensor of a surface-mounted device where high-density mounting is progressing, a thin-film type temperature sensor smaller than a chip-type temperature sensor (for example, Patent Document 2) is more suitable. It also has advantages such as a small sensor volume, being less likely to generate a temperature gradient within the sensor, and being able to provide more accurate measurement.

[0004] Japanese Patent Application Laid-Open No. 2023-9339, Japanese Patent Application Laid-Open No. 2016-51816

[0005] It is required to efficiently incorporate a thin-film type temperature sensor having a heat-sensitive thin film formed on a part of the surface of a substrate into a surface-mounted device. On the other hand, there also arises a problem that it is likely to receive external noise from the electronic components included in the surface-mounted device. That is, it is required to provide a temperature measurement with good responsiveness and accuracy.

[0006] The present invention has been made in view of the above circumstances, and its object is to provide a thin-film type temperature sensor having a heat-sensitive thin film formed on a part of the surface of a substrate, which can provide a temperature measurement with good responsiveness and accuracy, and is particularly suitable for application to a surface-mounted device, and a temperature sensing structure using the same.

[0007] The temperature sensor according to the present invention is a temperature sensor in which a heat-sensitive thin film is formed on a portion of the surface of a substrate, and includes an electrode set comprising: a pair of surface electrodes and a back electrode formed on the surface and back of the substrate, respectively, around the heat-sensitive thin film and facing each other with the substrate in between; a pass-through electrode that electrically connects the surface electrode and the back electrode; and a connecting electrode formed on the surface that electrically connects the heat-sensitive thin film and the surface electrode, wherein in the heat-sensitive region of the surface that includes at least the surface electrode, the heat-sensitive thin film and the connecting electrode on the inside, the height of the heat-sensitive thin film and the connecting electrode is formed to be less than or equal to the height of the surface electrode.

[0008] These features allow the thermal thin film to be interposed between the main substrate and the electronic component, enabling the thermal film to be brought close to the electronic component for responsive temperature measurement. Furthermore, the wiring to the thermal film can be shortened, suppressing the influence of external noise and allowing for accurate temperature measurement.

[0009] In the above-described invention, the thermal-sensitive thin film may be made of a thermistor and may be characterized by having the electrode set corresponding to each of the pair of terminals of the thermal-sensitive thin film. With this feature, a thermal-sensitive thin film with stable quality using a thermistor can be formed, and accurate temperature measurement can be performed.

[0010] In the invention described above, the heat-sensitive thin film and the connecting electrode may be characterized by having an insulating film covering their top surfaces. With this feature, good insulation can be provided to the electronic components, and accurate temperature measurement can be performed.

[0011] In the invention described above, the pass-through electrode may be characterized by including a via that penetrates the substrate, and electrically connecting the surface electrode and the back electrode via the via. Alternatively, the pass-through electrode may be characterized by electrically connecting the surface electrode and the back electrode via the side surface of the substrate. According to such features, the pass-through electrode can be positioned relatively freely, and accurate temperature measurement can be achieved.

[0012] In the above-described invention, the height of the thermal thin film and the connecting electrode may be 5 μm or less. Alternatively, the total thickness between the two surfaces of the surface electrode and the back electrode may be 60 μm or less. With these features, the wiring to the thermal thin film can be shortened, further suppressing the influence of external noise and enabling more accurate temperature measurement.

[0013] In the above-described invention, the heat-sensitive region may include one or more second electrode sets, each set comprising a second surface electrode and a second back electrode formed on the surface and back of the heat-sensitive thin film, respectively, facing each other with the substrate in between, and a second pass-through electrode electrically connecting the second surface electrode and the second back electrode, wherein the second surface electrode is formed at the same height as the surface electrode. Such a feature increases the degree of freedom for connection with other electronic components and enables accurate temperature measurement.

[0014] In the above-described invention, the surface may be characterized by having an external connection electrode electrically connected to the surface electrode on the outside of the heat-sensitive region. This feature increases the degree of freedom for connection with other electronic components and enables accurate temperature measurement.

[0015] In the above-described invention, the sealing wall may be formed at the same height as the surface electrode so as to surround the heat-sensitive region of the surface. With this feature, temperature changes in the heat-sensitive region can be reduced by sealing it from the external environment, and more accurate temperature measurement can be achieved.

[0016] Furthermore, the temperature sensing structure according to the present invention is a temperature sensing structure in which a temperature sensor having a heat-sensitive thin film formed on a portion of the surface of a substrate is interposed between a main substrate and an electronic component, wherein the temperature sensor includes an electrode set comprising a pair of surface electrodes and a back electrode formed on the front and back surfaces, respectively, around the heat-sensitive thin film and facing each other with the substrate in between, a pass-through electrode electrically connecting the surface electrode and the back electrode, and a connecting electrode formed on the surface electrically connecting the heat-sensitive thin film and the surface electrode, wherein in the heat-sensitive region of the surface that includes at least the surface electrode, the heat-sensitive thin film and the connecting electrode on the inside, the height of the heat-sensitive thin film and the connecting electrode is formed to be less than or equal to the height of the surface electrode.

[0017] These features allow the thermal thin film to be interposed between the main substrate and the electronic component, enabling the thermal film to be brought close to the electronic component for responsive temperature measurement. Furthermore, the wiring to the thermal film can be shortened, suppressing the influence of external noise and allowing for accurate temperature measurement.

[0018] In the above-described invention, the invention may further include one or more second electrode sets for supplying power to the electronic component, each set comprising: a second surface electrode and a second back electrode formed on the surface and the back surface, respectively, around the thermal thin film and facing each other with the substrate in between, in the thermal sensing region of the surface which includes at least the surface electrode, the thermal thin film, and the connecting electrode inside; and a second pass-through electrode that electrically connects the second surface electrode and the second back electrode, wherein the second surface electrode is formed at the same height as the surface electrode, and the height of the thermal thin film and the connecting electrode is formed to be less than or equal to the height of the surface electrode. According to this feature, a structure can be provided that easily supplies power to the electronic component and enables accurate temperature measurement.

[0019] In the above-described invention, the thermal-sensitive thin film may be made of a thermistor and may be characterized by having the electrode set corresponding to each of the pair of terminals of the thermal-sensitive thin film. With this feature, a thermal-sensitive thin film with stable quality using a thermistor can be formed, and accurate temperature measurement can be performed.

[0020] In the invention described above, the heat-sensitive thin film and the connecting electrode may be characterized by having an insulating film covering their top surfaces. With this feature, good insulation can be provided to the electronic components, and accurate temperature measurement can be performed.

[0021] In the invention described above, the pass-through electrode may be characterized by including a via that penetrates the substrate, and electrically connecting the surface electrode and the back electrode via the via. Alternatively, the pass-through electrode may be characterized by electrically connecting the surface electrode and the back electrode via the side surface of the substrate. According to such features, the pass-through electrode can be positioned relatively freely, and accurate temperature measurement can be achieved.

[0022] In the above-described invention, the surface may be characterized by having an external connection electrode electrically connected to the surface electrode on the outside of the heat-sensitive region. With this feature, connection to the outside can be made relatively freely, and accurate temperature measurement can be achieved.

[0023] In the above-described invention, the sealing wall may be formed at the same height as the surface electrode so as to surround the heat-sensitive region of the surface. With this feature, temperature changes in the heat-sensitive region can be reduced by sealing it from the external environment, and more accurate temperature measurement can be achieved.

[0024] This is a perspective view of the temperature sensor according to the first embodiment, viewed from the (a) front side and (b) back side. This is a side view of the same temperature sensor. This is a perspective view showing the temperature sensor according to the second embodiment. This is a side view of the same temperature sensor. This is a perspective view showing the temperature sensor according to the third embodiment, viewed from the (a) front side and (b) back side. This is a perspective view showing the temperature sensor according to the fourth embodiment, viewed from the (a) front side and (b) back side. This is a perspective view showing the temperature sensor according to the fifth embodiment, viewed from the (a) front side and (b) back side. This is a cross-sectional view showing the same temperature sensor. This is a perspective view of the temperature sensor according to the sixth embodiment. This is a perspective view of the temperature sensor assembly substrate according to the seventh embodiment. This is a side view of an electronic component in which the temperature sensors of the first embodiment are stacked and mounted. This is a side view of an electronic component in which the temperature sensors of the third embodiment are stacked and mounted.

[0025] Hereinafter, an embodiment of the temperature sensor of the present invention will be described with reference to Figures 1 to 12. In each figure, the scale of each component has been appropriately changed for explanatory purposes in order to make each component recognizable. Also, the same or equivalent parts are denoted by the same reference numerals, and redundant explanations are omitted.

[0026] (First Embodiment) The first embodiment will be described with reference to Figures 1 and 2. Figure 1 shows a temperature sensor according to the first embodiment, with Figure 1(a) being a perspective view from the front side and Figure 1(b) being a perspective view from the back side. Figure 2 is a side view of the same temperature sensor.

[0027] The temperature sensor 1 is a temperature sensor in which a heat-sensitive thin film 4 is formed on a portion of the surface 2a of a substrate 2. It comprises a flat substrate 2, a pair of surface electrodes 8a and a back electrode 9a formed on the surface 2a and back surface 2b, respectively, facing each other with the substrate 2 in between, and a further pair of surface electrodes 8b and a back electrode 9b. The surface electrodes 8a, 8b and the back electrodes 9a, 9b are electrically connected to each other by pass-through electrodes 10 that connect the surface 2a side and the back surface 2b side of the substrate 2 in each pair. In this embodiment, the pass-through electrodes 10 penetrate the substrate 2. In addition, the surface electrodes 8a and 8b are electrically connected to each of the pair of terminals of the heat-sensitive thin film 4 by connecting electrodes 3a and 3b formed on the surface 2a. In other words, the temperature sensor 1 includes an electrode set consisting of a set of surface electrode 8a, back electrode 9a, pass-through electrode 10 and connecting electrode 3a, and an electrode set consisting of a set of surface electrode 8b, back electrode 9b, pass-through electrode 10 and connecting electrode 3b.

[0028] The substrate 2 may be a silicon substrate, a glass substrate, a sapphire substrate, or a ceramic substrate made of alumina, zirconia, gallium arsenide, gallium nitride, indium phosphide, or other semiconductor material. The material of the substrate 2 is not particularly limited, but by using the same material as the base material of the electronic components to be stacked, or a material with the same coefficient of thermal expansion, it is possible to suppress the reduction in reliability due to damage or deformation caused by thermal stress after stacking. The thickness of the substrate 2 is preferably 10 to 100 μm. Furthermore, it is preferable that the substrate 2 is polished so that the smoothness of the surface 2a is 0.05 μm or less.

[0029] The connecting electrodes 3a and 3b are formed on the surface 2a of the substrate 2 by methods such as printing, vapor deposition, or sputtering, and then patterned by etching or the like. The connecting electrodes 3a and 3b can be made of metals such as titanium (Ti), chromium (Cr), nickel (Ni), tungsten (W), tantalum (Ta), ruthenium (Ru), ruthenium oxide (RuOx), platinum (Pt), gold (Au), palladium (Pd), or alloys or composites containing these metals. The thickness of the connecting electrodes 3a and 3b can be, for example, about 0.1 to 0.5 μm.

[0030] The thermal thin film 4 is patterned to electrically connect to the connecting electrodes 3a and 3b on the substrate 2. The thermal thin film 4 is a thermistor thin film made from a composite oxide composed of, for example, manganese, nickel, cobalt, and iron. The thickness of the thermal thin film 4 can be, for example, 0.3 to 2.0 μm. The connecting electrodes 3a and 3b may be in contact with the thermal thin film 4 either below, within, or on top of the film. Alternatively, a second thermal thin film may be formed on top of the thermal thin film 4 and connected by electrodes to create a laminated structure of multiple thermal thin films and multiple electrodes.

[0031] When electrodes such as connecting electrodes 3a and 3b are formed after the formation of the heat-sensitive thin film 4, a portion of the heat-sensitive thin film 4 may be removed during pattern formation such as etching, potentially changing its resistance. Furthermore, if the connecting electrodes 3a and 3b are formed on top of the heat-sensitive thin film 4, a step in the heat-sensitive thin film 4 may cause a break in the connecting electrodes 3a and 3b. For this reason, it is most preferable to form the connecting electrodes 3a and 3b so that they connect beneath the heat-sensitive thin film 4. The resistance of the heat-sensitive thin film 4 can also be finely adjusted by layering another heat-sensitive thin film for resistance adjustment on top of it.

[0032] Furthermore, if a material that can chemically react with the heat-sensitive thin film 4, such as a ceramic substrate, is used as the substrate 2, an insulating underlayer (not shown) may be formed beneath the heat-sensitive thin film 4. The thickness of the insulating underlayer can be, for example, 0.1 to 0.5 μm. The insulating underlayer is made of silicon dioxide (SiO₂). ２ ), silicon nitride (Si ３ N ４ It consists of the following materials and is deposited using methods such as sputtering and plasma CVD.

[0033] The heat-sensitive thin film 4 and the connecting electrodes 3a and 3b may also be formed including an insulating film 5 (see Figure 2; not shown in Figure 1) that covers their top surfaces. The insulating film 5 is, for example, a film with a thickness of 0.2 to 2.0 μm and is made of silicon dioxide (SiO₂ ２ ), silicon nitride (Si ３ N ４ The insulating film 5 is made of at least one of the following materials, such as glass, or a composite thereof. The insulating film 5 is mainly intended to protect the heat-sensitive thin film 4 and is formed to ensure the connection between the connecting electrodes 3a and 3b and the surface electrodes 8a and 8b. For example, when the insulating layer 5 is formed prior to the formation of the surface electrodes 8a and 8b, it is preferable to leave a portion of the connecting electrodes 3a and 3b exposed to serve as the connection portion for the surface electrodes 8a and 8b.

[0034] The surface electrodes 8a and 8b may be made of metals such as titanium (Ti), chromium (Cr), nickel (Ni), tungsten (W), tantalum (Ta), ruthenium (Ru), ruthenium oxide (RuOx), platinum (Pt), gold (Au), and palladium (Pd), or alloys or composites containing these metals. The shape of the surface electrodes 8a and 8b may be a pad or a bump, but the shape of the top view is not particularly limited. The surface electrodes 8a and 8b are formed by methods such as forming solder bumps using a ball mounting method, a plating method, or a screen printing method.

[0035] The back electrodes 9a and 9b are formed on the back surface 2b of the substrate 2, which is the opposite side of the surface 2a where the front electrodes 8a and 8b are formed, at positions opposite to the front electrodes 8a and 8b, respectively. The back electrodes 9a and 9b can be made of metals such as titanium (Ti), chromium (Cr), nickel (Ni), tungsten (W), tantalum (Ta), ruthenium (Ru), ruthenium oxide (RuOx), platinum (Pt), gold (Au), palladium (Pd), or alloys or composites containing these metals. The back electrodes 9a and 9b are obtained by patterning a metal film, which has been formed by sputtering or vapor deposition, by etching.

[0036] The pass-through electrode 10 electrically connects the surface electrodes 8a and 8b and the back electrodes 9a and 9b, respectively. Specifically, it is a through-hole via such as a TSV (Through silicon via) formed by etching the substrate 2 to create a through-hole state. Using a through-hole via for the pass-through electrode 10 is advantageous when performing hermetically sealed processing described later or when forming multiple temperature sensors on the same substrate, and it is also possible to process the pass-through electrode 10 simultaneously using a temperature sensor assembly substrate.

[0037] Here, in the heat-sensitive region 7, which includes at least the surface electrodes 8a, 8b, the heat-sensitive thin film 4, and the connecting electrodes 3a, 3b on the inside, the height h1 of the heat-sensitive thin film 4 and the connecting electrodes 3a, 3b (including the insulating film 5 if it is included) is formed to be less than or equal to the height h2 of the surface electrodes 8a, 8b. This allows the heat-sensitive thin film 4 to be brought close to the object whose temperature is to be measured above (the object whose temperature is to be measured) without interfering with the heat-sensitive thin film 4 and the connecting electrodes 3a, 3b, even when other electronic components are stacked on top of the temperature sensor 1. For example, by interposing the temperature sensor 1 between the main substrate 21 and the electronic component 22 (see Figure 11), the heat-sensitive thin film 4 can be brought close to the electronic component 22 whose temperature is to be measured. Note that heights h1 and h2 represent the height that allows the object to be brought close to the bottom surface of the electronic component 22 stacked on top. In other words, if the surface 2a of the substrate 2 is flat, it is the height from the surface 2a, and is the sum of the thicknesses of the films such as the heat-sensitive thin film 4 that are deposited on the surface 2a.

[0038] Here, from the viewpoint of measuring the temperature of the electronic component 22 with good responsiveness, it is preferable to bring the heat-sensitive thin film 4 close to the electronic component 22. From the viewpoint of ensuring conductivity and insulation as an electrical circuit of the temperature sensor 1, it is preferable to keep the heat-sensitive thin film 4 away from the electronic component 22. In other words, if electrical insulation of the heat-sensitive thin film 4 from the electronic component 22 can be ensured, it is preferable to bring the heat-sensitive thin film 4 close to the electronic component 22. For example, as described above, if the top surface of the heat-sensitive thin film 4 is an insulating film 5, or if the bottom surface of the electronic component 22 is an insulating material, it is preferable to bring the heat-sensitive thin film 4 into contact with the electronic component 22. In this sense, height h1 may include the same value as height h2. That is, the responsiveness of the temperature sensor 1 can be maximized when h1 = h2.

[0039] On the other hand, since the surface electrodes 8a and 8b and the back electrodes 9a and 9b are connected by the pass-through electrode 10 as described above, even if the temperature sensors 1 are stacked as described above, vertical conductivity can be easily and quickly secured. Furthermore, the wiring to the thermal thin film 4 can be shortened, suppressing the influence of external noise. As a result, temperature can be measured accurately.

[0040] (Second Embodiment) The second embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a perspective view showing the temperature sensor according to the second embodiment, and FIG. 4 is a side view showing the temperature sensor of the second embodiment.

[0041] In the second embodiment, the through - hole electrode 10 electrically connects the front - surface electrodes 8a, 8b and the back - surface electrodes 9a, 9b via the side surface of the substrate 2. That is, the through - hole electrode 10 is formed to connect to the front - surface electrode 8a or 8b, pass through the front - surface 2a, side surface, and back - surface 2b of the substrate 2 in order, and connect to each of the back - surface electrodes 9a or 9b. The through - hole electrode 10 can be formed in the same process using the same metal or alloy as the front - surface electrodes 8a, 8b and the back - surface electrodes 9a, 9b. For example, these electrode sets can be obtained by patterning a metal film formed by a method such as sputtering or vapor deposition by etching.

[0042] (Third Embodiment) The third embodiment will be described with reference to FIG. 5. FIG. 5 shows the temperature sensor according to the third embodiment, where (a) of the figure is a perspective view seen from the front - surface side and (b) of the figure is a perspective view seen from the back - surface side.

[0043] In the third embodiment, on the front - surface 2a of the substrate 2, external connection electrodes 11a, 11b are provided outside the heat - sensitive part region 7 so as to be connected to the front - surface electrodes 8a, 8b respectively, and can be connected to external electronic components or electronic circuits by wire bonding or the like. Since the external connection electrodes 11a, 11b are arranged outside the stacked mounting of the electronic components corresponding to the heat - sensitive part region 7, their thickness and shape are not particularly limited. As the material of the external connection electrodes 11a, 11b, for example, metals such as Au, Cu, Ag, Al are preferably used.

[0044] (Fourth Embodiment) The fourth embodiment will be described with reference to FIG. 6. FIG. 6 shows the temperature sensor according to the fourth embodiment, where (a) of the figure is a perspective view seen from the front - surface side and (b) of the figure is a perspective view seen from the back - surface side.

[0045] In the fourth embodiment, second surface electrodes 12a and 12b are formed on the surface 2a of the substrate 2, and second back surface electrodes 13a and 13b are formed on the back surface 2b. The second surface electrodes 12a and 12b and the second back surface electrodes 13a and 13b are electrically connected by second via electrodes 14 (see FIG. 8). Each set of the second surface electrodes 12a and 12b, the second back surface electrodes 13a and 13b, and the second via electrodes 14 constitutes a second electrode set. By including one or more second electrode sets, for example, it can serve as an electrode to be connected when further stacking and mounting external components. It can also be used as an electrode for supplying power to the stacked electronic component 22. Regarding other details such as the formation method, thickness, and shape of each electrode, they are the same as those of each electrode described in the first to third embodiments.

[0046] (The Fifth Embodiment) The fifth embodiment will be described with reference to FIGS. 7 and 8. FIG. 7 shows a temperature sensor according to the fifth embodiment, and FIG. 7(a) is a perspective view seen from the front side and FIG. 7(b) is a perspective view seen from the back side. FIG. 8 is a cross-sectional view showing the temperature sensor of the fifth embodiment.

[0047] In the fifth embodiment, a sealing wall 15 that can be hermetically sealed is provided further around the surface electrodes 8a and 8b on the substrate 2. The sealing wall 15 is formed at the same height as the surface electrodes 8a and 8b. As a result, the electronic components to be stacked and mounted are arranged to abut against the top surface of the sealing wall 15, serving as a lid for the temperature sensor 1, and can hermetically seal the heat-sensitive part region 7. By hermetically sealing the temperature sensor, the temperature can be accurately measured without being affected by the external environment. If the sealing wall 15 has the same thickness as the surface electrodes 8a and 8b, it can be hermetically sealed without affecting the stacking and mounting of the electronic components. Thereby, the heat-sensitive part region 7 can be sealed against the external environment, the temperature change in the heat-sensitive part region 7 due to the external environment can be reduced, and it contributes to accurate temperature measurement.

[0048] (The Sixth Embodiment) The sixth embodiment will be described with reference to FIG. 9. FIG. 9 is a perspective view of a temperature sensor according to the sixth embodiment.

[0049] In the sixth embodiment, multiple temperature sensors 1 are formed on the same substrate. The temperature sensors 1 may be any of the temperature sensors 1 described in the first to fifth embodiments. The thermal thin films 4 of the multiple temperature sensors 1 may be made of the same material, or they may be made of different materials. For example, by forming multiple thermal thin films 4 made of different materials, multiple different electronic components can be stacked and mounted on the same substrate. In other words, it becomes possible to arrange the thermal thin films 4 made of the optimal material according to the thermal characteristics of the electronic components. In particular, when the thermal thin film 4 is a thermistor thin film, a material with different characteristics can be selected according to the characteristics of the electronic components. For example, the material can be adjusted so that the B constant of the thermistor can be appropriately selected from 3000K to 4500K.

[0050] (Seventh Embodiment) The seventh embodiment will be described with reference to Figure 10. Figure 10 is a perspective view of a temperature sensor assembly substrate in which a large number of temperature sensors 1 according to the seventh embodiment are arranged.

[0051] The seventh embodiment is a temperature sensor assembly substrate 16 on which a large number of temperature sensors 1 are arranged on a substrate 2. The temperature sensors 1 may be any of the temperature sensors 1 described in the first to fifth embodiments. The temperature sensor assembly substrate 16 can be separated into individual temperature sensors 1 by, for example, attaching it to a dicing tape and then cutting it using a laser scribe or dicing saw.

[0052] (Eighth Embodiment) The eighth embodiment will be described with reference to Figures 11 and 12. Figure 11 is a side view of an electronic component in which the temperature sensors of the first embodiment are stacked, and Figure 12 is a side view of an electronic component in which the temperature sensors of the third embodiment are stacked.

[0053] The eighth embodiment is a temperature sensing structure 20 in which any of the temperature sensors 1 described in the first to sixth embodiments are stacked and mounted. The temperature sensor 1 is stacked between a main substrate 21 made of a printed circuit board and an electronic component 22 whose temperature is to be measured, and soldered. As described above, the temperature sensor 1 has a thermal thin film 4 that is less than or equal to the height of the surface electrodes 8a and 8b, so it can be stacked and mounted without the thermal thin film 4 interfering with the electronic component 22 whose temperature is to be measured. By using this temperature sensing structure 20 in which the electronic component 22 is stacked and mounted on the temperature sensor 1, the temperature sensor 1 can be placed closer to the electronic component 22 than when it is surface-mounted horizontally on the same substrate, enabling more accurate temperature measurement. Furthermore, as described above, by using a material for the substrate 2 of the temperature sensor 1 that has the same coefficient of thermal expansion as the base material of the electronic component 22, thermal stress generated in the temperature sensor 1 can be suppressed even when the electronic component 22 deforms due to heat generation, and the risk of damage to the temperature sensor 1 can be reduced.

[0054] The temperature sensor 1 can be positioned not only between the main substrate 21 and the electronic component 22, but also between the electronic components themselves. For example, it can be suitably used in cases where high-density mounting is required, such as with semiconductors, and can accurately measure the temperature of each stacked electronic component.

[0055] Furthermore, the temperature sensor 1 is extremely thin; for example, the total thickness between the upper surfaces of the surface electrodes 8a and 8b and the lower surfaces of the back electrodes 9a and 9b can be 60 μm or less. This allows for miniaturization of the temperature measurement structure in applications where the inclusion of a temperature sensor has previously increased the overall thickness, such as with quartz crystal oscillators.

[0056] Although embodiments and modifications based thereon have been described, the present invention is not necessarily limited to these examples. Furthermore, those skilled in the art will be able to find various alternative embodiments and modifications without departing from the spirit of the present invention or the scope of the attached claims.

[0057] 1. Temperature sensor 2. Substrate 3a, 3b. Connecting electrodes 4. Thermal thin film 8a, 8b. Surface electrodes 9a, 9b. Back electrodes 10. Pass-through electrode

Claims

1. A temperature sensor having a heat-sensitive thin film formed on a portion of the surface of a substrate, comprising an electrode set comprising: a pair of surface electrodes and a back electrode formed on the surface and back of the substrate, respectively, facing each other with the substrate in between around the heat-sensitive thin film; a pass-through electrode electrically connecting the surface electrode and the back electrode; and a connecting electrode formed on the surface electrically connecting the heat-sensitive thin film and the surface electrode, wherein in the heat-sensitive region of the surface that includes at least the surface electrode, the heat-sensitive thin film and the connecting electrode on the inside, the height of the heat-sensitive thin film and the connecting electrode is formed to be less than or equal to the height of the surface electrode.

2. The temperature sensor according to claim 1, characterized in that the heat-sensitive thin film is made of a thermistor and has the electrode set corresponding to each of the pair of terminals of the heat-sensitive thin film.

3. The temperature sensor according to claim 1, characterized in that the heat-sensitive thin film and the connecting electrode have an insulating film covering their top surfaces.

4. The temperature sensor according to claim 1, characterized in that the pass-through electrode includes a via that penetrates the substrate, and the surface electrode and the back electrode are electrically connected via the via.

5. The temperature sensor according to claim 1, characterized in that the pass-through electrode electrically connects the surface electrode and the back electrode via the side surface of the substrate.

6. The temperature sensor according to claim 1, characterized in that the height of the heat-sensitive thin film and the connecting electrode is 5 μm or less.

7. The temperature sensor according to claim 1, characterized in that the total thickness between the two surfaces of the surface electrode and the back electrode is 60 μm or less.

8. The temperature sensor according to claim 1, wherein the heat-sensitive region includes one or more second electrode sets, each set comprising a second surface electrode and a second back electrode formed on the surface and back of the heat-sensitive thin film, respectively, so as to face each other with the substrate in between, and a second pass-through electrode that electrically connects the second surface electrode and the second back electrode, wherein the second surface electrode is formed at the same height as the surface electrode.

9. The temperature sensor according to one of claims 1 to 8, characterized in that an external connection electrode electrically connected to the surface electrode is located outside the heat-sensitive region of the surface.

10. The temperature sensor according to one of claims 1 to 8, characterized in that a sealing wall is formed at the same height as the surface electrode so as to surround the heat-sensitive area of ​​the surface.

11. A temperature sensing structure in which a temperature sensor having a heat-sensitive thin film formed on a portion of the surface of a substrate is interposed between a main substrate and an electronic component, wherein the temperature sensor includes an electrode set comprising: a pair of surface electrodes and a back electrode formed on the front and back surfaces, respectively, around the heat-sensitive thin film and facing each other with the substrate in between; a pass-through electrode electrically connecting the surface electrode and the back electrode; and a connecting electrode formed on the surface electrically connecting the heat-sensitive thin film and the surface electrode, wherein in the heat-sensitive region of the surface that includes at least the surface electrode, the heat-sensitive thin film and the connecting electrode on the inside, the height of the heat-sensitive thin film and the connecting electrode is formed to be less than or equal to the height of the surface electrode.

12. Furthermore, in the heat-sensitive region of the surface, which includes at least the surface electrode, the heat-sensitive thin film, and the connecting electrode on the inside, the temperature sensing structure according to 11 is characterized in that it includes one or more second electrode sets for supplying power to the electronic component, each set comprising a second surface electrode and a second back electrode formed on the surface and the back surface, respectively, around the heat-sensitive thin film and facing each other with the substrate in between, and a second pass-through electrode that electrically connects the second surface electrode and the second back electrode, wherein the second surface electrode is formed at the same height as the surface electrode, and the height of the heat-sensitive thin film and the connecting electrode is formed to be less than or equal to the height of the surface electrode.

13. The temperature sensing structure according to claim 12, characterized in that the heat-sensitive thin film is made of a thermistor and has the electrode set corresponding to each of the pair of terminals of the heat-sensitive thin film.

14. The temperature sensing structure according to claim 13, characterized in that the heat-sensitive thin film and the connecting electrode have an insulating film covering their top surfaces.

15. The temperature sensing structure according to claim 11, characterized in that the pass-through electrode includes a via that penetrates the substrate, and the surface electrode and the back electrode are electrically connected via the via.

16. The temperature sensing structure according to claim 11, characterized in that the pass-through electrode electrically connects the surface electrode and the back electrode via the side surface of the substrate.

17. The temperature sensing structure according to one of claims 11 to 16, characterized in that an external connection electrode electrically connected to the surface electrode is located outside the heat-sensitive region of the surface.

18. The temperature sensing structure according to one of claims 11 to 16, characterized in that a sealing wall is formed at the same height as the surface electrode so as to surround the heat-sensitive region of the surface.

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