Measurement system

Abstract

According to one form of the invention, an assay system is provided. The measurement system includes a heat flow sensor and a housing. The heat flow sensor is provided with a substrate having electrical insulating properties, and a thermoelectric conversion unit provided on the substrate. The thermoelectric conversion unit is configured so as to generate an electromotive force on the basis of a temperature gradient along a gradient direction that is a direction from the substrate toward the thermoelectric conversion unit. The housing is configured so as to be able to accommodate the heat flow sensor, and includes a first wall portion and a second wall portion. The first wall portion is configured to exchange heat with the thermoelectric conversion portion via the substrate. The second wall part is configured so as to exchange heat with the thermoelectric conversion part without passing through a substrate that is the same as or different from the substrate.

Description

Technical Field

[0001] The present invention relates to a measurement system. Background Art

[0002] Patent Document 1 discloses a related art of a heat flux sensor that can suppress discomfort of a subject and can measure the physiological heat of the subject with high accuracy.

[0003] A heat flux sensor for measuring the heat released from a human body or the heat flux received by the human body includes a porous membrane and a thermocouple circuit array portion. The porous membrane is formed in a thin plate shape and has a continuous cell porous structure in which a plurality of holes communicating from one surface in the plate thickness direction to the other surface are formed. The thermocouple circuit array portion is provided inside the porous membrane and outputs a sensor signal corresponding to the heat flux in the plate thickness direction of the porous membrane.

[0004] Prior Art Documents

[0005] [Patent Document]

[0006] Patent Document 1: Japanese Patent Laid-Open No. 2019-132802 Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] However, there is still room for improvement in the technology of practically assembling a thermoelectric conversion portion such as this heat flux sensor into a measurement system. Means for Solving the Problems

[0009] According to one aspect of the present invention, there is provided a measurement system. The measurement system includes a heat flux sensor and a housing. The heat flux sensor includes a substrate having electrical insulation and a thermoelectric conversion portion provided on the substrate. The thermoelectric conversion portion is configured to generate an electromotive force based on a temperature gradient along a gradient direction that is a direction from the substrate toward the thermoelectric conversion portion. The housing is configured to accommodate the heat flux sensor and includes a first wall portion and a second wall portion. The first wall portion is configured to exchange heat with the thermoelectric conversion portion via the substrate. The second wall portion is configured to exchange heat with the thermoelectric conversion portion without passing through the same or different substrate as the substrate.

[0010] According to such a configuration, it is possible to promote the practical use of a measurement system including a thermoelectric conversion portion.

[0011] Brief Description of the Drawings

[0012] Figure 1 is an overall perspective view showing a configuration example of the measurement system 1.

[0013] Figure 2 is showing Figure 1 a cross-sectional view of the measurement system 1 shown in a plane having the x direction as a normal direction.

[0014] Figure 3 FIG. 32 is a diagram showing a configuration example of the measurement system 1 when the integrated circuit 32 as an example of a device is disposed in the exposed portion E1.

[0015] Figure 4 FIG. 37 is a diagram showing a configuration example of the thermoelectric conversion unit 51.

[0016] Figure 5 FIG. 40 is a diagram showing a configuration example of the thermoelectric conversion device 5 having a plurality of thermoelectric conversion units 51.

[0017] Figure 6 FIG. 43 is a diagram showing an example of the measurement system 1 not having the signal processing unit 3. DETAILED DESCRIPTION

[0018] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that in this specification and the accompanying drawings, for components having substantially the same functional configuration, repeated description is omitted by assigning the same reference numerals.

[0019] In addition, a program for implementing the software appearing in the present embodiment can be provided as a computer-readable non-transitory storage medium, can be provided so as to be downloadable from an external server, and can also be provided so as to realize its function on a client terminal by starting the program through an external computer (so-called cloud computing).

[0020] In addition, the "unit" in the present embodiment may include, for example, a combination of hardware resources implemented by a generalized circuit and software information processing that can be specifically realized by such hardware resources. In addition, although various information is processed in the present embodiment, this information is, for example, a numerical value having a physical meaning of a signal value representing voltage or current, or a signal value level that can be a binary bit set composed of 0 or 1, or is represented by quantum superposition (so-called qubit), and communication or calculation can be performed on a generalized circuit.

[0021] In addition, a generalized circuit is a circuit implemented by appropriately combining at least a circuit, circuitry, a processor, a memory, etc. That is, it includes application-specific integrated circuits (ASICs) for specific purposes, programmable logic devices (e.g., simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), and field programmable gate arrays (FPGAs)).

[0022] 1. Configuration example of measurement system 1

[0023] In this chapter, a configuration example of measurement system 1 will be described.

[0024] 1.1 Overall structure of measurement system 1

[0025] Figure 1 It is an overall perspective view showing a configuration example of measurement system 1. Note that the scale, positional relationship, etc. are only examples and are not limited thereto. As Figure 1 shown, measurement system 1 includes a measurement unit 2 and a signal processing unit 3.

[0026] <Measurement unit 2>

[0027] The measurement unit 2 is configured to output an electromotive force based on a temperature gradient along the z direction, which is an example of the gradient direction. The measurement unit 2 in this embodiment is formed in a film shape or a plate shape that expands in a plane with the z-axis direction, which is an example of the gradient direction, as the normal direction. Hereinafter, for the sake of convenience, the in-plane direction defining the plane perpendicular to the z-axis direction will be referred to as the x-axis direction and the y-axis direction. Note that the x-axis direction, the y-axis direction, and the z-axis direction are orthogonal to each other. The measurement unit 2 in this embodiment includes a housing 21 and a heat flux sensor 22.

[0028] <Housing 21>

[0029] The housing 21 is configured to be able to accommodate the heat flux sensor 22 described later. The shape of the housing 21 is arbitrary, for example, it is a rectangular parallelepiped shape. The material of the housing 21 is arbitrary, but it is preferably a material with relatively small thermal resistance and heat capacity so that heat can be transferred to the heat flux sensor 22 with a relatively small delay. For example, the material of the housing 21 can be metal or carbon, etc.

[0030] <Heat flux sensor 22>

[0031] The heat flux sensor 22 is configured to output an electromotive force based on the temperature gradient along the z-axis direction. The heat flux sensor 22 is accommodated inside the housing 21 in an electrically insulated manner from the housing 21.

[0032] <Signal processing unit 3>

[0033] The signal processing unit 3 is configured to process the signal output from the measurement unit 2 and includes a control board 31 and an integrated circuit 32.

[0034] <Control board 31>

[0035] The control board 31 is connected to at least a part of the measurement unit 2, such as the housing 21, and is configured to transmit the signal from the heat flux sensor 22. In the present embodiment, the control board 31 is exposed outside the housing 21. Therefore, the control board 31 is preferably a flexible board that can elastically deform at least with respect to an external force in the z-axis direction. Thereby, the possibility of damage to the control board 31 due to interference with the outside can be reduced.

[0036] <Integrated circuit 32>

[0037] The integrated circuit 32 is configured to perform predetermined signal processing based at least on the electromotive force output from the thermoelectric conversion unit 41. The integrated circuit 32 is configured to acquire the electromotive force by being electrically connected to the heat flux sensor 22. According to such a configuration, a measurement system 1 capable of performing signal processing based on the electromotive force can be provided. The integrated circuit 32 includes, for example, a communication unit, a storage unit, and a processor, and these constituent elements are electrically connected via a communication bus inside the integrated circuit 32.

[0038] The communication unit is preferably a wired communication device, such as USB, IEEE1394, Thunderbolt (registered trademark), wired LAN network communication, etc., but may also include wireless LAN network communication, mobile communication such as 3G / LTE / 5G, Bluetooth (BLU ETOOTH, registered trademark) communication, etc. as needed. That is, it is more preferably configured as a collection of these multiple communication devices. That is, the integrated circuit 32 can communicate various information with the outside via the communication unit and the network.

[0039] The storage unit stores various information defined by the above description. This can be implemented, for example, as a storage device such as a solid state drive (SSD) that stores various programs related to the measurement system 1 executed by the processor, or as a memory such as a random access memory (RAM) that stores temporary information (parameters, arrays, etc.) required for program operation. The storage unit stores various programs or variables related to the integrated circuit 32 executed by the processor.

[0040] The processor processes and controls the overall operations related to the measurement system 1. The processor is, for example, a Central Processing Unit (CPU) not shown in the figure. The processor realizes various functions related to the measurement system 1 by reading a predetermined program stored in the storage unit. That is, the information processing of the software stored in the storage unit is specifically realized by the processor as an example of hardware, and thus can be executed as each functional unit included in the processor. These will be further described in detail in the next section. Note that the processor is not limited to a single one, and may also be configured to have multiple processors according to each function. In addition, it may also be a combination of these. Note that the integrated circuit 32 may also be composed only of a processor. In addition, the integrated circuit 32 is not limited to a digital circuit including a processor, and may also be an analog circuit.

[0041] 1.2. Details of the measurement system 1

[0042] In this section, the details of the measurement system 1 described in the previous section will be described. Figure 2 is Figure 1 A cross-sectional view of the measurement system 1 shown in the plane with the x direction as the normal direction.

[0043] As Figure 2 shown, the housing 21 includes a first wall portion 211 and a second wall portion 212. The first wall portion 211 and the second wall portion 212 are configured to extend in a plate shape in the xy plane. In the present embodiment, for the sake of convenience of explanation, it is assumed that the first wall portion 211 and the second wall portion 212 have the same shape. The first wall portion 211 and the second wall portion 212 are disposed opposite to each other with a separation in the z-axis direction. Note that at least a part of the outer periphery of the first wall portion 211 is connected to at least a part of the outer periphery of the second wall portion 212 by a peripheral wall portion not shown. Thus, a region capable of accommodating the heat flux sensor 22 is formed between the first wall portion 211 and the second wall portion 212.

[0044] <Heat flux sensor 22>

[0045] The heat flux sensor 22 is configured to perform heat exchange with a measurement object not shown via the housing 21. The heat flux sensor 22 includes a substrate 4 and a thermoelectric conversion device 5.

[0046] The substrate 4 is configured to have electrical insulation. From the viewpoint of durability within the housing 21, the substrate 4 preferably has rigidity against an external force in the z-axis direction. In the present embodiment, the substrate 4 is formed in a flat plate shape with the z-axis direction as the normal direction. The specific form of the substrate 4 is arbitrary. For example, the substrate 4 may be a chip on which an LSI (Large Scale Integration) such as Si is assembled, or may be a structure in which an IC is mounted on a substrate with good heat dissipation, such as an insulating film such as polyamide, a flexible printed circuit board, a PCB, Al, Cu, MgO, a sapphire substrate, GaN, SiC, SiO2 / Si, Ta2O5 / Ta, A12O3, A12O3 / Al, SiN, Ti, TiO2 / Ti, CuO / Cu, Ga2O3, GaAs, lnAs, lnSb, etc. or a composite thereof, or a combination of these.

[0047] <First adhesive layer Gr1>

[0048] The heat flux sensor 22 may further include a first adhesive layer Gr1. The first adhesive layer Gr1 is configured to bond the substrate 4 to the first wall portion 211. The specific form of the first adhesive layer Gr1 is arbitrary, but a material having a relatively small thermal resistance and heat capacity is preferred. In other words, regarding the heat flux sensor 22 related to the present embodiment, a heat flux sensor film (an example of a circuit composed of the thermoelectric conversion element 511, that is, the thermoelectric conversion unit 41) is formed on the substrate, and the substrate is bonded to the housing 21 (specifically, the first wall portion 211). The upper surface of the heat flux sensor film may also be bonded to the housing 21.

[0049] The thermoelectric conversion device 5 includes at least one (one in the present embodiment) thermoelectric conversion unit 51. The thermoelectric conversion unit 51 is configured to generate an electromotive force based on a temperature gradient along the z-axis direction. For example, the thermoelectric conversion unit 51 is configured to generate an electromotive force based on the anomalous Nernst effect. According to such a configuration, compared with the case of using a Seebeck element, the volume of the measurement system 1 in the gradient direction can be made more compact. Note that at least a part of the thermoelectric conversion unit 51 may also be configured to generate an electromotive force based on the Seebeck effect.

[0050] The thermoelectric conversion unit 51 is provided on the substrate 4 in the z-axis direction. The z-axis direction is an example of the gradient direction as the direction from the substrate 4 toward the thermoelectric conversion unit 51. Specifically, the thermoelectric conversion unit 51 is provided on the surface of the substrate 4 opposite to the surface connected to the first wall portion 211. Thereby, the first wall portion 211 is configured to perform heat exchange with the thermoelectric conversion unit 51 via the substrate 4.

[0051] In addition, the thermoelectric conversion unit 51 is connected to the second wall portion 212 via the second adhesive layer Gr2 without passing through the substrate 4 or an insulating rigid member other than the substrate 4. The specific form of the second adhesive layer Gr2 is the same as that of the first adhesive layer Gr1. Thus, the second wall portion 212 is configured to exchange heat with the thermoelectric conversion unit 51 without passing through a substrate that is the same as or different from the substrate 4. According to such a configuration, compared with the prior art, the volume of the measurement system 1 in the gradient direction can be made more compact. Note that the region of the thermoelectric conversion unit 51 that faces the second wall portion 212, in other words, the region to which the second adhesive layer Gr2 is bonded, may also be configured to have electrical insulation from the second wall portion 212 by laminating an insulating film. In other words, a member that does not have rigidity but has electrical insulation may be interposed between the thermoelectric conversion unit 51 and the second wall portion 212.

[0052] The heat flux sensor 22 may also include an exposed portion E1 that faces the second wall portion 212 with a gap therebetween at least in the gradient direction. For example, the exposed portion E1 may be configured such that at least a part of the region of the thermoelectric conversion unit 51 that faces the second wall portion 212 is exposed with respect to the second wall portion 212. Various devices may be arranged on the exposed portion E1. Thereby, the internal space of the housing 21 can be utilized more effectively. Figure 3 FIG. shows a configuration example of the measurement system 1 in the case where the integrated circuit 32, which is an example of a device, is arranged on the exposed portion E1. As Figure 3 shown, the integrated circuit 32, which is an example of a device, may also be arranged on the exposed portion E1 such that it faces the second wall portion 212 at least in the gradient direction. According to such a structure, compared with the case where the integrated circuit is located outside the housing 21, the possibility of interference between the integrated circuit and an external object can be further reduced.

[0053] 1.3. Details of the thermoelectric conversion unit 51

[0054] Here, a configuration example of one thermoelectric conversion unit 51 will be described. Figure 4 FIG. shows a configuration example of the thermoelectric conversion unit 51. As Figure 4 shown, the thermoelectric conversion unit 51 includes a plurality of thermoelectric conversion elements 511, wirings 512, and a pair of output terminals 513.

[0055] <Thermoelectric conversion element 511>

[0056] The thermoelectric conversion element 511 is configured to generate an electromotive force based on the thermoelectric effect and due to a temperature gradient in the z-axis direction (i.e., the movement of heat). Each of the multiple thermoelectric conversion elements 511 is formed to extend along the y-axis direction. In addition, each of the thermoelectric conversion elements 511 is configured so that the thermoelectric conversion element 511 has spontaneous magnetization in a direction different from the z-axis direction as the gradient direction (in this embodiment, the x-axis direction), thereby being configured to generate an electromotive force in the in-plane direction due to the above-mentioned temperature gradient. The thermoelectric conversion element 511 can be formed in a thin film shape, for example. The thermoelectric conversion portion 51 can include magnetic domains configured to be magnetized along the x-axis direction as one of the in-plane directions of the thin film. Note that the thermoelectric conversion element 511 can also be formed in a block shape. Note that the material constituting the thermoelectric conversion element 511 can be, for example, composed of a topological ferromagnet or a topological antiferromagnet called a Weyl semimetal, or can be composed of a ferrimagnet, or can be a combination of these. These specific materials will be described in detail below.

[0057] <Wiring 512>

[0058] The wiring 512 is configured to connect the plurality of thermoelectric conversion units 51 in series so that the respective polarities are aligned.

[0059] <Output Terminal 513>

[0060] The output terminal 513 is a terminal configured to output the total value of the electromotive force output from the plurality of thermoelectric conversion elements 511 as a whole. Note that the output terminal 513 may not be actually installed as a terminal for connection, but may be a virtual terminal connected to an external element. In this embodiment, the thermoelectric conversion section 51 has a pair of output terminals 513, and a total electromotive force V1, which is the total value of the electromotive force of the thermoelectric conversion elements 511, is output from the pair of output terminals 513. In this embodiment, the thermoelectric conversion section 51 outputs the total electromotive force V1 from the output terminals 513 due to the heat flow accompanying the temperature gradient. Ideally, V1 = n × k × M × Q (where k is a proportional constant, M is the magnetization of the thermoelectric conversion element 511, Q is the amount of heat transfer, and n is the number of thermoelectric conversion elements 511 connected in series). Note that the direction of heat transfer corresponds to the temperature gradient. The polarity of the thermoelectric conversion elements 511 included in one thermoelectric conversion section 51 is the same.

[0061] 2. Configuration Example of Thermoelectric Converter 5 Having Multiple Thermoelectric Converter Sections 51

[0062] In this chapter, a configuration example of a thermoelectric conversion device 5 including a plurality of thermoelectric conversion sections 51 will be described. Figure 5 1 is a diagram showing a configuration example of a thermoelectric converter 5 having a plurality of thermoelectric converters 51. Note that, for configurations common to the above configurations, descriptions thereof may be omitted by assigning the same reference numerals.

[0063] As shown Figure 5 in the present embodiment, the thermoelectric conversion device 5 includes, as a plurality of thermoelectric conversion units 51, four thermoelectric conversion units 51a to 51d and an insulating film 52 having electrical insulation. The plurality of thermoelectric conversion units 51a to 51d are the same as the above-described thermoelectric conversion unit 51 described with reference to Figure 3 and include a plurality of thermoelectric conversion elements 511, wirings 512, and output terminals 513. Each of the plurality of thermoelectric conversion units 51a to 51d is stacked on the substrate 4 in the z-axis direction in order starting from the thermoelectric conversion unit 51a. The thermoelectric conversion unit 51a is connected to the substrate 4, and the thermoelectric conversion unit 51d is connected to the second wall portion 212 via the second adhesive layer Gr2. Thus, the four thermoelectric conversion units 51a to 51d form a laminate. In other words, the measurement system 1 further includes a laminate. The laminate is configured by stacking a plurality of thermoelectric conversion elements 511 on the substrate 4 in the gradient direction. With such a structure, the measurement system 1 can be made smaller in volume in the in-plane direction. Note that the heat flow flowing into each of the plurality of thermoelectric conversion units 51a to 51d constituting the laminate is substantially common.

[0064] In the present embodiment, the thermoelectric conversion elements 511 included in the thermoelectric conversion unit 51a and the thermoelectric conversion unit 51c are configured to extend along the x-axis direction and have spontaneous magnetization in the y-axis direction. In addition, the thermoelectric conversion elements 511 of the thermoelectric conversion unit 51a and the thermoelectric conversion elements 511 of the thermoelectric conversion unit 51c are configured such that the directions of spontaneous magnetization are opposite (for example, anti-parallel). As a result, the polarities of the thermoelectric conversion unit 51a and the thermoelectric conversion unit 51c are configured to be reversed. In this way, the thermoelectric conversion unit 51a and the thermoelectric conversion unit 51c can each output an electromotive force in the reverse direction with respect to the temperature gradient in the same z-axis direction. The thermoelectric conversion units 51a and 51c are examples of the first thermoelectric conversion elements, and the y-axis direction is an example of the first output direction. In other words, each of the plurality of first thermoelectric conversion elements is configured to output an electromotive force along the first output direction, which is one of the in-plane directions of the substrate 4, based on the temperature gradient. The polarity of at least one of the plurality of first thermoelectric conversion elements is different from the polarity of at least another of the plurality of first thermoelectric conversion elements. With such a configuration, for example, the influence of the electromotive force caused by the temperature gradient in the in-plane direction can be canceled, and thus a measurement system 1 with higher accuracy can be provided.

[0065] In the present embodiment, the thermoelectric conversion elements 511 included in the thermoelectric conversion sections 51b and 51d are configured to extend along an in-plane direction (specifically, the y-axis direction) different from that of the thermoelectric conversion elements 511 included in the thermoelectric conversion sections 51a and 51c, and have spontaneous magnetization in the x-axis direction. In addition, the thermoelectric conversion elements 511 of the thermoelectric conversion section 51b and the thermoelectric conversion elements 511 of the thermoelectric conversion section 51d are configured such that the directions of spontaneous magnetization are opposite (for example, anti-parallel). As a result, the polarities of the thermoelectric conversion section 51b and the thermoelectric conversion section 51d are configured to be reversed. In this way, the thermoelectric conversion section 51b and the thermoelectric conversion section 51d can respectively output reverse electromotive forces with respect to the temperature gradient in the same z-axis direction. The thermoelectric conversion elements 511 included in the thermoelectric conversion sections 51b and 51d are examples of the second thermoelectric conversion elements, and the x-axis direction is an example of the second output direction. In other words, the thermoelectric conversion section 51 includes a plurality of second thermoelectric conversion elements. Each of the plurality of second thermoelectric conversion elements is configured to output an electromotive force along a second output direction that is one of the in-plane directions of the substrate 4 and different from the first output direction, based on the temperature gradient. The polarity of at least one of the plurality of second thermoelectric conversion elements is different from the polarity of at least another of the plurality of second thermoelectric conversion elements. According to such a configuration, the influence of the in-plane temperature gradient in a plurality of directions can be reduced. Note that it can also be considered that the thermoelectric conversion sections 51a and 51b constitute one thermoelectric conversion unit, the thermoelectric conversion sections 51c and 51d constitute one thermoelectric conversion unit, and the polarities of these thermoelectric conversion units are different. Note that the first output direction and the second output direction only need to be along one direction of the in-plane direction, can be arbitrary, and do not necessarily need to be perpendicular to the z-axis direction (in other words, the gradient direction). In addition, the first output direction and the second output direction only need to intersect, and do not necessarily need to be orthogonal to each other. In addition, the number of stacked thermoelectric conversion sections 51 is not limited to four.

[0066] 3. Others

[0067] The measurement system 1 is not limited to the structure of the above embodiment. For example, regarding the measurement system 1 related to the above embodiment, the following form can be adopted.

[0068] The integrated circuit 32 can be provided on the substrate 4. In addition, the integrated circuit 32 can also be provided outside the housing 21.

[0069] The first wall portion 211 and the second wall portion 212 can both be configured to be stacked in close contact with the substrate 4 and the thermoelectric conversion device 5.

[0070] For example, the measurement system 1 may not include the signal processing unit 3. Figure 6 FIG. is an example of a measurement system 1 that does not include the signal processing unit 3. As Figure 6As shown, for example, the measurement system 1 may also include only the measurement unit 2. In this case, the thermoelectric conversion unit 51 of the measurement unit 2 may not have the exposed portion E1, and its entire surface may be bonded to the second wall portion 212. With such a configuration, by expanding the region of the thermoelectric conversion unit with respect to the temperature gradient, a measurement system 1 with higher sensitivity to the temperature gradient can be provided.

[0071] Alternatively, it can be provided in various forms described below.

[0072] (1) A measurement system, comprising a heat flux sensor and a housing; the heat flux sensor includes a substrate having electrical insulation and a thermoelectric conversion unit provided on the substrate, the thermoelectric conversion unit being configured to generate an electromotive force based on a temperature gradient along a gradient direction as the direction from the substrate toward the thermoelectric conversion unit, the housing being configured to accommodate the heat flux sensor and including a first wall portion and a second wall portion, the first wall portion being configured to exchange heat with the thermoelectric conversion unit via the substrate, and the second wall portion being configured to exchange heat with the thermoelectric conversion unit without passing through a substrate that is the same as or different from the substrate.

[0073] With such a configuration, compared with the prior art, the volume of the measurement system in the gradient direction can be made more compact.

[0074] (2) The measurement system according to (1) above, wherein the thermoelectric conversion unit includes a plurality of first thermoelectric conversion elements, each of the plurality of first thermoelectric conversion elements being configured to output an electromotive force along a first output direction that is one of the in-plane directions of the substrate based on the temperature gradient, and the polarities of at least one of the plurality of first thermoelectric conversion elements being different from the polarities of at least another of the plurality of first thermoelectric conversion elements.

[0075] With such a configuration, for example, the influence of the electromotive force caused by the in-plane temperature gradient can be canceled, and thus a measurement system with higher accuracy can be provided.

[0076] (3) The measurement system according to (2) above, further including a laminate configured to be formed by laminating the plurality of first thermoelectric conversion elements on the substrate along the gradient direction.

[0077] With such a configuration, the volume of the measurement system in the in-plane direction can be made smaller.

[0078] (4) The measurement system according to (2) or (3) above, wherein the thermoelectric conversion unit includes a plurality of second thermoelectric conversion elements, and each of the plurality of second thermoelectric conversion elements is configured to output an electromotive force along a second output direction that is one of the in-plane directions of the substrate and different from the first output direction based on the temperature gradient, and the polarities of at least one of the plurality of second thermoelectric conversion elements are different from the polarities of at least another of the plurality of second thermoelectric conversion elements.

[0079] With such a configuration, the influence of in-plane temperature gradients in multiple directions can be reduced.

[0080] (( )5) The measurement system according to any one of (1) to (4) above, further comprising an integrated circuit configured to acquire the electromotive force, and the integrated circuit is configured to perform predetermined signal processing based at least on the electromotive force output from the thermoelectric conversion unit.

[0081] With such a configuration, a measurement system capable of performing signal processing based on the electromotive force can be provided.

[0082] (6) The measurement system according to (5) above, wherein the integrated circuit is disposed on the substrate so as to be accommodated in the housing.

[0083] With such a configuration, compared with the case where the integrated circuit is located outside the housing, the possibility of interference between the integrated circuit and external objects can be further reduced.

[0084] (7) The measurement system according to any one of (1) to (6) above, wherein the thermoelectric conversion unit is configured to generate the electromotive force based on the anomalous Nernst effect.

[0085] With such a configuration, compared with the case of using a Seebeck element, the volume of the measurement system in the gradient direction can be made more compact.

[0086] Of course, it is not limited to this.

[0087] Finally, although various embodiments related to the present disclosure have been described, these are only presented as examples and are not intended to limit the scope of the invention. The new embodiment can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. The embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and its equivalents.

[0088] In addition, the following forms should also be noted.

[0089] Conventional heat flux sensors are heat flux sensors that utilize the Seebeck effect. For these sensors that utilize the Seebeck effect, both the heat capacity and the thermal resistance are large, and a robust structure is made with a sturdy housing for protection. Therefore, it becomes a sensor with a large thermal resistance and heat capacity, and since it obstructs the heat flow path, it is impossible to accurately measure the heat flux.

[0090] Therefore, in the device related to the present embodiment and the system using the device, for example, a heat flux sensor film that exhibits an anomalous Nernst effect and has high thermal conductivity is fabricated on a substrate with good thermal conductivity, and the sensor substrate uses an insulating and highly thermally conductive housing. Thereby, the heat flux can be measured more accurately.

[0091] Regarding the heat flux sensor (an example of a device) according to the present embodiment, from the viewpoint of responsiveness, a heat flux sensor based on the thin-film type anomalous Nernst effect is preferred. The element (thermoelectric conversion element) of the heat flux sensor (i.e., the thermoelectric conversion device) can be composed of a compound that exhibits an anomalous Nernst effect. This element can be, for example, composed of a topological ferromagnet or a topological antiferromagnet called a Weyl semimetal, or can be composed of a ferrimagnet, or a combination of these. The topological ferromagnet can be an alloy of Co2TX such as Co2MnGa (X is any one of Si, Ge, Sn, Al, and Ga), or can be an alloy of a well-known topological ferromagnet with a composition formula of Fe3X (X is a typical element such as Al or Ga or a stoichiometric or non-stoichiometric composition of a transition element). In addition, the topological antiferromagnet can be a well-known topological antiferromagnet such as Mn3X (X is one or more elements selected from Sn, Ge, Ga, Pt, Ir, Rh, or a compound thereof). Regarding the composition ratio of the alloy that constitutes the topological ferromagnet or topological antiferromagnet, it is not necessarily only the stoichiometric composition ratio as described above, as long as it partially has a stoichiometric structure, and there is no particular limitation on the composition ratio. Regarding the compound that constitutes the element, for example, it is composed of an alloy having a transition metal, and the alloy is a compound having a crystal structure with a Kagome lattice plane composed of a transition metal and can exhibit an anomalous Nernst effect. The ferrimagnet is not particularly limited as long as it can exhibit an anomalous Nernst effect. There is no particular limitation on the structure of the element, and a well-known structure can be used. In addition, the element according to the present embodiment can be provided by means such as sputtering, evaporation, MBE, electroplating, sintering, printing, and pasting. The heat flux sensor according to the present embodiment is not only a device for measuring heat, but can also be configured as a device for detecting light or chemical substances, etc.

[0092] Regarding the heat flux sensor according to this embodiment, a heat flux sensor film (a circuit composed of thermoelectric conversion elements) is formed on a substrate, and the substrate is bonded to a housing. The upper surface of the heat flux sensor film may also be bonded to the housing. At this time, the material of the bonding film or the housing is preferably a material having a relatively small thermal resistance and heat capacity. For example, the material of the housing may be a metal, carbon, or the like.

[0093] In addition, the heat flux sensor film may be a multilayer film, a film including a magnet layer (hard magnetic layer), a film including a coil layer, a film in which an insulating layer is inserted and a thermoelectric conversion element circuit is stacked, or any combination thereof. In addition, in order to cancel the Seebeck effect that becomes noise of the abnormal Nernst effect, a heat flux sensor having a plurality (preferably four) different polarities may be fabricated on a plane or in the form of a multilayer film. For example, the sum of the A, B, C, and D signals shown in the figure can cancel the Seebeck effect and extract the abnormal Nernst effect (heat flux in the z direction). A and D can detect the heat flux in the x direction from the Seebeck effect, and C and B can detect the heat flux in the y direction from the Seebeck effect. The order in the figure can be arbitrary. In addition, a thin bonding layer may be provided between the sensor film and the substrate. The bonding layer only needs to have a low thermal resistance, and its material is not strictly required. The housing is preferably low in thermal resistance.

[0094] In addition, by providing a signal processing integrated circuit (IC) for signal processing including a MUX, amplifier, ADC, processor, DSP, memory, communication function, etc., higher-precision measurement can be achieved. Here, the substrate may be, for example, a chip on which an LSI such as Si is assembled, or a structure in which an IC is mounted on a substrate having good heat dissipation, such as an insulating film such as polyamide, a flexible circuit board, a PCB, Al, Cu, MgO, a sapphire substrate, GaN, SiC, SiO2 / Si, Ta2O5 / Ta, Al2O3, Al2O3 / Al, SiN, Ti, TiO2 / Ti, CuO / Cu, Ga2O3, GaAs, InAs, InGaAs, InSb, etc. or a composite thereof, or a combination of these. The terminals may also be led out to a flexible substrate. There are no particular limitations on these structures.

[0095] In addition, by opening the upper or lower part of the heat flux sensor part to have a contact point with the outside, the thermal resistance can be reduced. The structure of the opening may be a physically open structure or a structure connected to a member having a small thermal resistance. Furthermore, the PKG (package) of the IC may be the PKG shown in the figure or a package such as WLCSP.

[0096] The following describes a modification example of this embodiment. For example, by providing a film or the like that can absorb electromagnetic waves including light in the heat flux sensor unit, electromagnetic waves can be detected. Further, by providing an optical filter, electromagnetic waves (light) in a selected wavelength range can be detected only, and thus selectivity can be improved. Further, by coating or providing a substance that reacts with or adsorbs to a gas, a liquid, or a solution on the heat flux sensor, a gas or the like that reacts with the substance can be detected. Further, it is sufficient that the above substance is thermally bonded to the heat flux sensor, and it is not necessarily required to be directly provided on the heat flux sensor.

[0097] The following describes other modification examples of this embodiment. In the interior or other layers of the LSI, a coil for generating a magnetic field for heat flux sensor modulation or heat for catalyst heating may also be provided. In such a coil, since heat can be conducted, measurement can be performed normally. The position where the coil is provided only needs to be a position with good heat dissipation. This is not particularly limited to the application object of the heat flux sensor. For example, it may be a heat flux sensor of the anomalous Nernst effect, and it is not necessarily a device for detecting electromagnetic waves or substances.

[0098] Description of Reference Numerals

[0099] 1: Measurement system,

[0100] 2: Measurement unit,

[0101] 3: Signal processing unit,

[0102] 4: Substrate,

[0103] 5: Thermoelectric conversion device,

[0104] 21: Housing,

[0105] 211: First wall portion,

[0106] 212: Second wall portion,

[0107] 22: Heat flux sensor,

[0108] 31: Control substrate,

[0109] 32: Integrated circuit,

[0110] 41: Thermoelectric conversion portion,

[0111] 51: Thermoelectric conversion portion,

[0112] 51a: Thermoelectric conversion portion,

[0113] 51b: Thermoelectric conversion portion,

[0114] 51c: Thermoelectric conversion portion,

[0115] 51d: Thermoelectric conversion section,

[0116] 511: Thermoelectric conversion element,

[0117] 512: Wiring,

[0118] 513: Output terminal,

[0119] 52: Insulating film,

[0120] E1: Exposed portion,

[0121] Gr1: First adhesive layer,

[0122] Gr2: Second adhesive layer.

Claims

1. A measurement system, wherein, it includes a heat flux sensor and a housing; the heat flux sensor includes a substrate having electrical insulation and a thermoelectric conversion portion provided on the substrate, the thermoelectric conversion portion is configured to generate an electromotive force based on a temperature gradient along a gradient direction which is a direction from the substrate toward the thermoelectric conversion portion, the housing is configured to be able to accommodate the heat flux sensor and includes a first wall portion and a second wall portion, the first wall portion is configured to perform heat exchange with the thermoelectric conversion portion via the substrate, the second wall portion is configured to perform heat exchange with the thermoelectric conversion portion without passing through a substrate that is the same as or different from the substrate.

2. The measurement system according to claim 1, wherein, the thermoelectric conversion portion includes a plurality of first thermoelectric conversion elements, each of the plurality of first thermoelectric conversion elements is configured to output an electromotive force along a first output direction which is one of the in-plane directions of the substrate based on the temperature gradient, the polarity of at least one of the plurality of first thermoelectric conversion elements is different from the polarity of at least another of the plurality of first thermoelectric conversion elements.

3. The measurement system according to claim 2, wherein, it further includes a laminate, the laminate is configured to be formed by laminating the plurality of first thermoelectric conversion elements on the substrate along the gradient direction.

4. The measurement system according to claim 2 or 3, wherein, the thermoelectric conversion portion includes a plurality of second thermoelectric conversion elements, each of the plurality of second thermoelectric conversion elements is configured to output an electromotive force along a second output direction which is one of the in-plane directions of the substrate and different from the first output direction based on the temperature gradient, the polarity of at least one of the plurality of second thermoelectric conversion elements is different from the polarity of at least another of the plurality of second thermoelectric conversion elements.

5. The measurement system according to any one of claims 1 to 4, wherein, it further includes an integrated circuit configured to acquire the electromotive force, the integrated circuit is configured to perform a predetermined signal process based at least on the electromotive force output from the thermoelectric conversion portion.

6. The measurement system according to claim 5, wherein, the integrated circuit is provided on the substrate so as to be accommodated in the housing.

7. The measurement system according to any one of claims 1 to 6, wherein, the thermoelectric conversion portion is configured to generate the electromotive force based on the anomalous Nernst effect.

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