Heat flux measurement system and heat flux measurement method

Abstract

One embodiment of the present invention provides a heat flux measurement system that is mountable on an insulating substrate. The insulating substrate comprises: a main surface on which an element can be disposed; and a conductive pattern having electrical conductivity on the main surface. The heat flux measurement system comprises: a transmission part and at least one heat flux sensor. The transmission part comprises: a connection section that is thermally connectable to the conductive pattern of the insulating substrate; and an extension section that extends from the connection section along the main surface. The heat flux sensor is thermally connected to the extension section, and is configured to output an electrical signal on the basis of a component along a plane-perpendicular direction perpendicular to the main surface among heat fluxes generated through heat exchange with the extension section.

Description

Heat Flux Measurement System and Heat Flux Measurement Method

[0001] The present invention relates to a heat flux measurement system and a heat flux measurement method.

[0002] Patent Document 1 discloses a technique related to a thermoelectric conversion device that can generate a voltage due to a temperature difference and can suppress a leakage magnetic field much more than conventionally.

[0003] Japanese Patent Application Laid-Open No. 2017-084854

[0004] There is still room for improvement in the technique for measuring the heat flux from a heat source such as an element mounted on an insulating substrate using such a heat flux sensor.

[0005] According to one aspect of the present invention, there is provided a heat flux measurement system that can be mounted on an insulating substrate, the insulating substrate including a main surface on which an element can be disposed and a conductive pattern having electrical conductivity on the main surface, the heat flux measurement system including a transmission unit and at least one heat flux sensor, the transmission unit including a connection unit that can be thermally connected to the conductive pattern of the insulating substrate and an extending unit that extends along the main surface from the connection unit, the heat flux sensor being thermally connected to the extending unit and configured to output an electrical signal based on a component along a plane perpendicular direction perpendicular to the main surface among the heat fluxes generated by heat exchange with the extending unit.

[0006] According to such a configuration, it is possible to provide a technique for measuring the heat flux from a heat source such as an element mounted on an insulating substrate, which is more improved.

[0007] This shows an example configuration of the heat flux measurement system 1000. This is a cross-sectional view taken along line A-A of the heat flux measurement system 1000 shown in Figure 1. This is a diagram showing an example of the configuration of the internal circuit 4. This is a diagram showing an example configuration of the heat flux sensor 43. This is a diagram showing another example of the internal circuit 4. This is a diagram showing another example of the internal circuit 4. This is a diagram showing another example of the internal circuit 4. This is a diagram showing a modified version of the internal circuit 4. This is a diagram showing a modified version of the internal circuit 4. This is a diagram showing a modified version of the internal circuit 4. This is a diagram showing a modified version of the internal circuit 4. This is a diagram showing an example configuration of the heat flux measurement system 1000 equipped with a heat sink 5. This is a diagram showing an example of the heat flux measurement device 1 shown in Figure 13. This is a diagram showing an example of the heat flux measurement device 1 equipped with a magnetic field application unit 6. This is a diagram showing an example configuration of the internal circuit 4 equipped with a plurality of heat flux sensors 43 having different polarities. This is a diagram showing an example configuration of the heat flux measurement device 1 when equipped with a plurality of heat flux sensors 43c, 43d shown in Figure 16. This is a diagram showing another example of the heat flux measurement system 1000.

[0008] Embodiments of the present invention will be described below with reference to the drawings. The various features shown in the embodiments below can be combined with each other.

[0009] Incidentally, the program for realizing the software appearing in one embodiment may be provided as a computer-readable non-transitor-readable medium, or it may be provided so that it can be downloaded from an external server, or it may be provided so that the program is launched on an external computer and its functions are realized on a client terminal (so-called cloud computing).

[0010] Furthermore, in various information processing according to one embodiment, an input and an output corresponding to the input can be realized. Here, as long as an output is obtained as a result of the input, the form of the information referenced in such information processing (hereinafter referred to as "reference information") is not limited. The reference information may be, for example, rule-based information such as a database, a lookup table, or a predetermined function (including a decision formula such as a regression equation constructed by a statistical method), or a trained model that has been pre-trained to learn the correlation between input and output, or a generative AI such as a large-scale language model that can output a desired result by inputting a prompt (these models include parameters that construct the correlation relationship between input and output) or a visual language model.

[0011] Furthermore, in one embodiment, "part" may include, for example, hardware resources implemented by a circuit in a broad sense, and the information processing of software that can be specifically realized by these hardware resources. Also, in one embodiment, various types of information are handled, and this information can be represented, for example, by the physical values ​​of signal values ​​representing voltage and current, the high or low values ​​of signal values ​​as a set of binary bits composed of 0s or 1s, or by quantum superposition (so-called qubits), and communication and calculations can be performed on a circuit in a broad sense.

[0012] Furthermore, a circuit in a broad sense is a circuit realized by combining at least an appropriate combination of circuits, circuits, processors, and memory. The processor may be a general-purpose processor or a dedicated circuit. In other words, this includes application-specific integrated circuits (ASICs), programmable logic devices (for example, simple programmable logic devices (SPLDs), complex programmable logic devices (CPLDs), and field programmable gate arrays (FPGAs)), etc.

[0013] Furthermore, the heat flux sensor used in the measuring device described below is preferably a thin-film type thermoelectric conversion device based on the anomalous Nernst effect, from the viewpoint of responsiveness. The elements of the thermoelectric conversion device (thermoelectric elements) may be composed of alloys or compounds that exhibit the anomalous Nernst effect. These elements may be composed of, for example, topological ferromagnetic materials or topological antiferromagnetic materials called Weyl semimetals, or ferrimagnetic materials, or combinations thereof. Topological ferromagnetic materials are Co ２ Co such as MnGa ２ It may be a metal with a TX composition (where T is a transition metal and X is one of Si, Ge, Sn, Al, and Ga), or the composition formula may be Fe ３ X may be a known alloy of a topological ferromagnetic material, such as a metal represented by X (where X is a stoichiometric composition of a typical element or transition element such as Al or Ga). Furthermore, the topological antiferromagnetic material may be Mn. ３ X (where X is one or more elements selected from Sn, Ge, Ga, Pt, Ir, Rh, or compounds thereof) may be a known topological antiferromagnetic material. The compound constituting the element may be, for example, an alloy having a transition metal, and the alloy may be a compound having a crystal structure with a kagome lattice plane due to the transition metal, and may exhibit an anomalous Nernst effect. The ferrimagnetic material is also not particularly limited as long as it exhibits an anomalous Nernst effect. The structure of the element is not particularly limited, and known structures can be used. Furthermore, the element according to this embodiment may be provided by sputtering, vapor deposition, MBE, plating, granulation, 3D printing, melting, sintering, printing, bonding, etc. Since the thin-film type heat flux sensor based on the anomalous Nernst effect is an alloy, its thermal resistance and heat capacity are lower than those of a heat flux sensor that exhibits the Seebeck effect. Therefore, its sensitivity is higher and its time response is better than that of a conventional heat flux sensor that exhibits the Seebeck effect. The thickness of the element of the heat flux sensor is not particularly limited, but it is preferably less than 1 micrometer.

[0014] Furthermore, the heat flux sensor according to this embodiment may be a heat flux sensor that exhibits the Seebeck effect described above. To improve thermal responsiveness, for example, the thickness of the Seebeck effect element is preferably less than 250 micrometers, more preferably less than 100 micrometers, even more preferably less than 10 micrometers, and even more preferably less than 1 micrometer.

[0015] 1. Example Configuration of Heat Flux Measurement System 1000 Figure 1 shows an example configuration of the heat flux measurement system 1000. Figure 2 is a cross-sectional view taken along line A-A of the heat flux measurement system 1000 shown in Figure 1. As shown in Figures 1 and 2, the heat flux measurement system 1000 comprises an insulating substrate 2000, an element 3000, a heat flux measurement device 1, and a signal processing unit 4000.

[0016] The insulating substrate 2000 comprises a main surface 2000a on which elements 3000 and the like can be arranged, and conductive patterns PT1 to PT4.

[0017] The main surface 2000a is a plane perpendicular to the plane-perpendicular direction D1. For the sake of explanation, the two directions perpendicular to the plane-perpendicular direction D1 will be referred to as the first in-plane direction D2 and the second in-plane direction D3. The first in-plane direction D2 and the second in-plane direction D3 are perpendicular to each other.

[0018] Conduction patterns PT1 to PT4 have electrical conductivity on the main surface 2000a. The insulating substrate 2000 is, for example, FR-4, ceramic (AlN / Al ２ O ３ The printed circuit board is made of glass epoxy, polyimide, etc., but is not limited to these and can be any material. For example, the insulating substrate 2000 may be a flexible substrate. The conductive pattern PT1 is a pattern of conductors laminated on the main surface 2000a, and can be made of copper, for example. Here, the conductive patterns PT1 to PT3 are arranged apart in the first in-plane direction D2. These patterns may be electrically conductive or insulated from each other. The conductive pattern PT4 is arranged near the conductive pattern PT3 and is electrically insulated from the other conductive patterns PT1 to PT3.

[0019] The element 3000 may be an active element such as an integrated circuit chip, or a passive element such as a resistor, capacitor, or inductor. The element 3000 is connected to the conduction pattern PT1 and performs processing according to the power or signal transmitted from the conduction pattern PT1.

[0020] The heat flux measuring device 1 is mountable on an insulating substrate 2000 and outputs an electrical signal corresponding to the heat flux on the insulating substrate 2000. The heat flux on the insulating substrate 2000 is caused, for example, by the heat generation of elements on the same insulating substrate 2000. Therefore, the electrical signal correlates with the heat generation state of the elements 3000 mounted on the insulating substrate 2000. In this embodiment, the heat flux measuring device 1 is positioned in the region between conduction patterns PT2 and PT3 on the main surface 2000a. The heat flux measuring device 1 comprises a housing 2, an outer lead 3, and an internal circuit 4.

[0021] The housing 2 can be formed using an insulator such as epoxy resin or silica filler, similar to the housings that cover typical semiconductor chips. Preferably, the housing 2 is made of a material with high thermal conductivity.

[0022] The outer lead 3 is a conductor extending from the outer periphery or bottom of the housing 2 along the main surface 2000a. At least one of the outer lead 3 is electrically connected to the conduction pattern PT2. Also, at least one of the outer lead 3 is electrically connected to the conduction pattern PT3. The outer lead 3 transmits the heat flux from the insulating substrate 2000 into the interior of the housing. Here, the outer lead 3 includes a first outer lead 31 and a second outer lead 32. The first outer lead 31 is a terminal that functions as a heat channel for heat exchange with the insulating substrate 2000 and is connected to conduction patterns (e.g., conduction patterns PT2 and PT3) that have an extent on the main surface 2000a. The second outer lead 32 is configured to output an electrical signal based on the component of the heat flux flowing into the interior of the housing 2 via the first outer lead 31 along the direction D1 perpendicular to the surface. The second outer lead 32 is connected to conduction pattern PT4, which is insulated from conduction patterns PT1 to PT3. Therefore, the outer lead 3 can function as a connection point that can be thermally connected to the conductive patterns PT1 to PT3 of the insulating substrate 2000.

[0023] The internal circuit 4 is an electrical and thermal circuit housed inside the housing 2 and is connected to the first outer lead 31 and the second outer lead 32. The internal circuit 4 directs the heat flux flowing into the housing 2 along the main surface 2000a via the first outer lead 31 in the direction D1 perpendicular to the surface within the housing 2. The component of the heat flux along the direction D1 perpendicular to the surface is converted into an electrical signal by a heat flux sensor 43, which will be described later. The specific configuration of the internal circuit 4 will be described later.

[0024] The signal processing unit 4000 is configured to acquire electrical signals output from the internal circuit 4 via the conduction pattern PT4. Based on the acquired electrical signals, the signal processing unit 4000 performs various signal processing related to heat flux. For example, the signal processing unit 4000 may calculate the instantaneous power consumption of the element 3000 based on the acquired electrical signals. Based on the calculation result, the signal processing unit 4000 may generate a command to control the operation of the element 3000, or it may present the calculation result to the user.

[0025] 2. Internal Circuit 4 Next, various configuration examples related to the internal circuit 4 described above will be explained.

[0026] 2.1. Example of Internal Circuit 4 Configuration Figure 3 shows an example of the configuration of the internal circuit 4. The straight arrows in Figure 3 represent the heat flux from the insulating substrate 2000. As shown in Figure 3, the internal circuit 4 comprises an inner lead 40, an adhesive layer 41, a substrate layer 42, a heat flux sensor 43, a conductive wire 44, and an inner lead 45.

[0027] The inner lead 40 is connected to at least one of the first outer leads 31. In this embodiment, the inner lead 40 is connected to four first outer leads 31 that are connected to conduction pattern PT2, which is closer to the element 3000, among the conduction patterns PT2 and PT3. The inner lead 40 extends away from the insulating substrate 2000 in the perpendicular direction D1 and along the first in-plane direction D2. As a result, the heat flux flowing into the housing 2 from the first outer leads 31 is transmitted through the inner lead 40 along the first in-plane direction D2. Therefore, the inner lead 40 can function as one of the extensions that extend from the outer lead 3 (specifically the first outer lead 31) as a connection part along the main surface 2000a of the insulating substrate 2000. At the tip of the inner lead 40, an adhesive layer 41, a substrate layer 42, and a heat flux sensor 43 are sequentially laminated along the perpendicular direction D1.

[0028] The adhesive layer 41 is a layer for bonding the substrate layer 42 onto the inner lead 40, and any material can be used for this layer.

[0029] The substrate layer 42 is, for example, a semiconductor substrate such as a silicon substrate. Various circuit patterns can be formed on the substrate layer 42.

[0030] The heat flux sensor 43 is thermally connected to the inner lead 40 as an extended portion. Here, "thermally connected" is not limited to the two members being directly connected, but may also include being connected via another solid thermally conductive member (e.g., an adhesive layer 41 or a substrate layer 42). The heat flux sensor 43 is configured to output an electrical signal based on the component of the heat flux generated by heat exchange with the inner lead 40 along the perpendicular direction D1 perpendicular to the main surface 2000a of the insulating substrate 2000. For example, the heat flux sensor 43 comprises a first surface 43a and a second surface 43b located opposite each other in the perpendicular direction D1, and is configured to output an electrical signal based on the heat flux between the first surface 43a and the second surface 43b (in other words, the heat flux flowing in the perpendicular direction D1). The first surface 43a faces the substrate layer 42 in the perpendicular direction D1. In this case, the first surface 43a (and similarly the second surface 43b) can be (thermally) connected to the inner lead 40 such that it overlaps with at least a portion of the inner lead 40 when the heat flux sensor 43 is viewed in plan from the direction D1 perpendicular to the surface. In this embodiment, since the adhesive layer 41, the substrate layer 42, and the heat flux sensor 43 are laminated on the inner lead 40, the entire first surface 43a is connected to the inner lead 40 such that it overlaps with the inner lead 40. With this configuration, the heat flux conduction efficiency can be improved.

[0031] Here, an example of the configuration of the heat flux sensor 43 will be described. Figure 4 shows an example of the configuration of the heat flux sensor 43. As shown in Figure 4, the heat flux sensor 43 comprises a plurality of thermoelectric conversion elements 431, wiring 432, and a pair of output terminals 433. In this embodiment, the thermoelectric conversion elements 431, wiring 432, and output terminals 433 are laminated on a substrate layer 42.

[0032] <Thermoelectric Conversion Element 431> The thermoelectric conversion element 431 is configured to generate a thermoelectric electromotive force based on the thermoelectric effect, caused by a heat flux in the direction perpendicular to the plane D1. Each of the plurality of thermoelectric conversion elements 431 is formed to extend along a second in-plane direction D3. Furthermore, each of the thermoelectric conversion elements 431 has an easy magnetization axis along a direction different from the direction perpendicular to the plane D1 (in this embodiment, a first in-plane direction D2), and generates an electromotive force in the second in-plane direction D3 due to the heat flux. The thermoelectric conversion element 431 can be formed, for example, as a thin film. The thermoelectric conversion element 431 may also be formed in bulk form. The material constituting the thermoelectric conversion element 431 may be, for example, a topological ferromagnet or topological antiferromagnet called a Weyl semimetal, or a ferrimagnetic material, or a combination thereof. These specific materials are as described above. In other words, the heat flux sensor 43 may include a non-collinear antiferromagnetic material having an easy magnetization axis along an in-plane direction D2 perpendicular to the plane direction D1. With such a configuration, it is possible to provide a heat flux sensor 43 that is thin in the plane direction D1 and highly sensitive based on the anomalous Nernst effect, making it easy to house inside the housing 2.

[0033] <Wiring 432> Wiring 432 connects multiple thermoelectric elements 431 in series so that their polarities are aligned. In this embodiment, wiring 432 connects multiple thermoelectric elements 431 in a meander structure.

[0034] <Output Terminal 433> The output terminal 433 is configured to output the total electromotive force V1 as an electrical signal. For example, the output terminal 433 is configured to output the sum of the electromotive forces output from all of the thermoelectric conversion elements 431. Note that the output terminal 433 does not have to be actually implemented as a connection terminal, and may be a virtual terminal connected to an external element. The output terminal 433 outputs the total electromotive force V1, which is the sum of the thermoelectric electromotive forces of the thermoelectric conversion elements 431. In this embodiment, the heat flux sensor 43 outputs the total electromotive force V1 that is output from the output terminal 433 due to the heat flux. Ideally, V1 = n × k × M × Q (where k is a proportionality constant, M is the magnetization of the thermoelectric conversion element 431, Q is the heat flux, and n is the number of thermoelectric conversion elements 431 connected in series). Since the sign of the total electromotive force V1 is reversed when the direction of the magnetization M is reversed, the direction of the magnetization M is correlated with the polarity of the heat flux sensor 43. The polarity of each thermoelectric conversion element 431 included in one heat flux sensor 43 is the same. The output terminal 433 is connected, for example, to a conductive pattern on the substrate layer 42.

[0035] Returning to Figure 3, the conductive wires 44 are connected to the circuit pattern on the substrate layer 42. At least two of the conductive wires 44 are connected to the output terminals 433 of the heat flux sensor 43.

[0036] The inner lead 45 is connected to the first outer lead 31 and the second outer lead 32, respectively, and extends from the first outer lead 31 and the second outer lead 32 along the first in-plane direction D2. The inner lead 45 is connected to the conductive wire 44. The heat flux transmitted via the inner lead 40, adhesive layer 41, substrate layer 42, and heat flux sensor 43 is transmitted to the first outer lead 31 and the second outer lead 32 via the conductive wire 44 and the inner lead 45. The transmitted heat flux is then transmitted to the conductive pattern PT3 of the insulating substrate 2000. Here, the conductive wire 44 and the inner lead 45 extend along the first in-plane direction D2 and are thermally connected to the conductive pattern PT3, and therefore function as extensions that extend from the first outer lead 31 and the second outer lead 32 as connection points along the main surface 2000a of the insulating substrate 2000. In this way, the outer leads 31 and 32 and the inner leads 40 and 45 can function as a transmission unit as a whole.

[0037] Here, the inner lead 45 connected to the second outer lead 32 is connected to the output terminal 433 via a conductive wire 44. Therefore, the second outer lead 32 can output the total electromotive force V1 as an electrical signal. In other words, the inner lead 45 and the second outer lead 32, acting as transmission parts, are connected to at least one of the multiple output terminals 433. With this configuration, the configuration of the device can be simplified.

[0038] With the above configuration, by placing the heat flux measuring device 1 on the insulating substrate 2000, the heat flux sensor 43 can measure the heat flux from a heat source such as an element 3000 mounted on the insulating substrate 2000.

[0039] 2.2. Alternative Examples of Internal Circuit 4 The configuration of internal circuit 4 is not limited to this example. Figure 5 shows an alternative example of internal circuit 4. In the following description, the explanation may be omitted by using common reference numerals for configurations corresponding to the above-described configuration.

[0040] As shown in FIG. 5, the heat flux measurement device 1 according to the present embodiment further includes a lead frame 46 and a thermal coupling portion 47. The lead frame 46 extends along the upper wall inside the housing 2. At this time, the lead frame 46 extends at least along the first in-plane direction D2. Further, the lead frame 46 is connected to the inner lead 40, thereby transmitting the heat flux propagated from the first outer lead 31 along the first in-plane direction D2. Therefore, the lead frame 46 can also function as an extending portion.

[0041] The thermal coupling portion 47 connects the second surface 43b of the heat flux sensor 43 and the lead frame 46 along the plane normal direction D1. The thermal coupling portion 47 can be formed of a highly thermally conductive insulating material. The heat flux transmitted through the lead frame 46 flows through the heat flux sensor 43 via the thermal coupling portion 47. Thereby, the heat flux sensor 43 outputs the total electromotive force V1.

[0042] In the present embodiment, the inner lead 45 extends along the first in-plane direction D2. The adhesive layer 41, the substrate layer 42, and the heat flux sensor 43 are laminated on the inner lead 45. Therefore, the heat flux flowing through the heat flux sensor 43 along the plane normal direction D1 is transmitted along the first in-plane direction D2 via the inner lead \\(45\\), transmitted to the second outer lead 32, and transmitted to the conduction pattern PT3.

[0043] Thus, the direction in which the heat flux flows may be reversed in the plane normal direction D1.

[0044] Further, the internal circuit 4 does not necessarily need to be configured to transmit the heat flux in the first in-plane direction D2 on both the first surface 43a side and the second surface 43b side of the heat flux sensor 43. FIG. 6 is a diagram showing another example of the internal circuit 4. As shown in FIG. 6, for example, when the insulating substrate 2000 has the conduction pattern PT5 directly below the heat flux measurement device 1, the internal circuit 4 may further include a heat conduction portion 45a. The heat conduction portion 45a is provided directly above the conduction pattern PT5. Further, an adhesive layer 41, a substrate layer 42, a heat flux sensor 43, and a thermal coupling portion 47 are laminated on the heat conduction portion 45a. Thereby, the heat flux flowing in the plane normal direction D1 through the lead frame 46 is transmitted to the conduction pattern PT5 through the heat conduction portion 45a. Thus, the internal circuit 4 may be configured to transmit the heat flux in the first in-plane direction D2 only on one of the first surface 43a and the second surface 43b of the heat flux sensor 43.

[0045] FIG. 7 is a diagram showing another example of the internal circuit 4. As shown in FIG. 7, the lead frame 46 is coupled to the thermal coupling portion 47, but is not directly connected to the first outer lead 31 and the second outer lead 32. In such a case, the heat flux flowing in from the conduction pattern PT5 is transmitted along the plane normal direction D1 through the adhesive layer 41, the substrate layer 42, and the heat flux sensor 43, and is transmitted in the first in-plane direction D2 toward the inner lead 45 through the conduction wire 44, and is transmitted from the inner lead 45 to the second outer lead 32 in the first in-plane direction D2. Thus, it is sufficient if there is a mechanism for changing the direction of the heat flux from the plane normal direction D1 to the first in-plane direction D2 in the heat flux transmission path.

[0046] Figure 8 shows another example of the internal circuit 4. As shown in Figure 8, the heat flux measuring device 1 may further include a base portion 45b that is spaced apart from the insulating substrate 2000. In this case, the base portion 45b is connected to the housing 2 or an internal component of the housing 2 by die bonding or lead bonding. The adhesive layer 41, the substrate layer 42, and the heat flux sensor 43 are laminated on the base portion 45b. In this example, the internal circuit 4 also includes a conductive wire 48 in addition to the conductive wire 44. The conductive wire 48 electrically and thermally connects the first outer lead 31, which is connected to the conductive pattern PT2, to the second surface 43b of the heat flux sensor 43.

[0047] Furthermore, the conductive wire 44 is connected to the first surface 43a of the heat flux sensor 43 via the substrate layer 42. Therefore, the heat flux is transmitted in the first in-plane direction D2 via the conductive wire 48, then transmitted within the heat flux sensor 43 along the perpendicular direction D1, then transmitted along the first in-plane direction D2 via the conductive wire 44, and finally transmitted to the first outer lead 31 and the second outer lead 32 via the inner lead 45. Thus, the transmission part that transmits the heat flux in the first in-plane direction D2 is not limited to members such as the inner leads 40 and 45, but may also be a flexible member such as the conductive wires 44 and 48.

[0048] In other words, the transmission unit comprises an inner lead 45 and conduction wire 44 as a first transmission unit and an inner lead 40 and conduction wire 48 as a second transmission unit. The inner lead 45 and conduction wire 44 and the inner lead 40 and conduction wire 48 are configured to be connectable to different conduction patterns PT2 and PT3. The inner lead 45 and conduction wire 44 are connected to the first surface 43a. The inner lead 40 and conduction wire 48 are connected to the second surface 43b. With this configuration, heat flux can be transmitted more efficiently.

[0049] Furthermore, the internal circuit 4 may be stacked in reverse order, for example, the adhesive layer 41, the substrate layer 42, and the heat flux sensor 43, in the direction perpendicular to the plane D1, so as to approach the insulating substrate 2000. Figures 9 to 12 show modified examples of the internal circuit 4. As shown in Figures 9 to 11, the adhesive layer 41, the substrate layer 42, and the heat flux sensor 43 may be arranged so as to approach the insulating substrate 2000 in the direction perpendicular to the plane D1. Also, as shown in Figure 12, the lead frame 46 is not limited to being arranged along the upper wall of the housing 2.

[0050] 2.3. Example of introducing a heat sink 5 In each of the exemplary embodiments described above, the heat flux measurement system 1000 may further include a heat sink 5. Figure 13 is a diagram showing an example configuration of the heat flux measurement system 1000 including a heat sink 5. As shown in Figure 13, the heat sink 5 connects the element 3000 and the housing 2 so as to cover them from the perpendicular direction D1 and extends along the first in-plane direction D2. Figure 14 is a diagram showing an example of the heat flux measurement device 1 shown in Figure 13. The internal circuit 4 shown in Figure 13 is the same as that shown in Figure 7. The heat sink 5 thermally connects the element 3000 and the heat flux sensor 43 so as to cover the element 3000 and the heat flux sensor 43 from the perpendicular direction D1. With this configuration, heat can be introduced to the heat flux measurement device 1 along the first in-plane direction D2 via the heat sink 5. The heatsink 5 is not connected to the element 3000, but may be connected to the outer surface of the housing 2 to function in order to maintain a constant temperature on the second surface 43b.

[0051] 2.4. Example of Introduction of Magnetic Field Application Unit 6 In each of the exemplary embodiments described above, the heat flux measuring device 1 may further include a magnetic field application unit 6. Figure 15 shows an example of a heat flux measuring device 1 equipped with a magnetic field application unit 6. As shown in Figure 15, the magnetic field application unit 6 is configured to apply a magnetic field along a first in-plane direction D2 to the antiferromagnetic material constituting the thermoelectric conversion element 431 of the heat flux sensor 43. For example, the magnetic field application unit 6 is stacked on the outside (here, the top surface) of the housing 2 and applies an external magnetic field along the first in-plane direction D2 to the heat flux sensor 43. The magnetic field application unit 6 may be an electromagnet as long as it can apply an external magnetic field, but it is preferable that it be a ferromagnetic material that can become a permanent magnet. As the ferromagnetic material, it is particularly preferable that it be a material that can be stacked on the housing 2, for example, ferrite. With such a configuration, the magnetic domains of the heat flux sensor 43 can be aligned, and a heat flux measuring device 1 that is more robust to disturbances can be provided.

[0052] Figure 16 shows an example of the configuration of an internal circuit 4 equipped with a plurality of heat flux sensors 43 having opposite polarities. As shown in Figure 16, the internal circuit 4 is equipped with a plurality of heat flux sensors 43c, 43d whose magnetization directions M are opposite to each other. These configurations are the same as the heat flux sensors 43 described above, except for the direction of magnetization M. These heat flux sensors 43c, 43d are arranged apart in a second in-plane direction D3 so as to intersect the direction of magnetization M with each other.

[0053] Figure 17 shows an example configuration of the heat flux measuring device 1 when it is equipped with a plurality of heat flux sensors 43c and 43d as shown in Figure 16. As shown in Figure 17, the heat flux measuring device 1 according to this embodiment is equipped with four second outer leads 32 connected to the output terminals 433 of the first heat flux sensor 43c and the second heat flux sensor 43d, respectively. The signal processing unit 4000 can reduce noise superimposed on electrical signals based on two types of electrical signals output from these four second outer leads 32. For example, the signal processing unit 4000 can reduce noise N by multiplying the difference between the total electromotive force V1 = n × k × M × Q + N output from the first heat flux sensor 43c, including noise N, and the total electromotive force V2 = n × k × (-M) × Q + N output from the second heat flux sensor 43d by 1 / 2. In this case, the magnetic field application unit 6 may include a first magnetic field application unit 6a and a second magnetic field application unit 6b. The first magnetic field application unit 6a is provided directly above the first heat flux sensor 43c and is configured to apply an external magnetic field along the direction of the magnetization M of the first heat flux sensor 43c. The second magnetic field application unit 6b is provided directly above the second heat flux sensor 43d and is configured to apply an external magnetic field along the direction of the spontaneous magnetization -M of the second heat flux sensor 43d. In this way, the magnetic field application unit 6 is configured to apply magnetic fields opposite to each of the multiple heat flux sensors 43c and 43d. With this configuration, a heat flux measuring device 1 that is more robust to disturbances can be provided. In this case, the magnetic field application unit 6 includes a ferromagnetic material located in the direction D1 perpendicular to the plane of the heat flux sensors 43c and 43d. The easy magnetization axis of the ferromagnetic material is along the easy magnetization axis of the antiferromagnetic material. With this configuration, a heat flux measuring device 1 that is more robust to disturbances can be provided. In this embodiment, both of these easy magnetization axes are aligned with the first in-plane direction D2, and their magnetization directions can be defined to be antiparallel.

[0054] 2.5. Example of the configuration of the thermal induction section 2000b In the exemplary embodiment described above, the insulating substrate 2000 of the heat flux measurement system 1000 may be provided with a thermal induction section 2000b. Figure 18 shows another example of the heat flux measurement system 1000. The arrows in Figure 18 indicate the heat flux flowing on the insulating substrate 2000. As shown in Figure 18, the thermal induction section 2000b is configured to preferentially transmit the heat flux from the first in-plane direction D2 toward the heat flux measurement device 1 (particularly the heat flux sensor 43). With such a configuration, the accuracy of heat flux measurement by the heat flux sensor 43 can be improved.

[0055] For example, the heat induction section 2000b may include conductor patterns 2100 and 2200 using a heat conductor electrically insulated from the element 3000. The conductor patterns 2100 and 2200 are formed in a planar shape (for example, rectangular) on the main surface 2000a. A heat flux measuring device 1 is positioned between the conductor patterns 2100 and 2200. Of the plurality of first outer leads 31, those positioned close to the element 3000 in the first in-plane direction D2 (in this embodiment, the first outer lead 31 extending from the housing 2 to the left in Figure 18) are connected to the conductor pattern 2100. Of the plurality of first outer leads 31, those positioned farther from the element 3000 in the first in-plane direction D2 (in this embodiment, the first outer lead 31 extending from the housing 2 to the right in Figure 18) are connected to the conductor pattern 2200. As an example, the second outer lead 32, which outputs the total electromotive force V1 from the internal circuit 4, is not connected to the conductor patterns 2100 and 2200. With this configuration, the possibility of heat flux inducing noise in the electrical signal output from the internal circuit 4 can be reduced.

[0056] The width of the conductor patterns 2100, 2200 in a direction intersecting the direction in which the inner leads 40, etc., which function as extensions, transmit heat flux (first in-plane direction D2) (for example, the second in-plane direction D3) is preferably wider than the width of the housing 2 in the second in-plane direction D3 (more specifically, the maximum distance between the ends of the connection portion between the first outer lead 31 and the conductor patterns 2100, 2200 in the second in-plane direction D3). This allows the heat flux to be preferentially transmitted from a wider area on the insulating substrate 2000 towards the heat flux sensor 43. The widths of the conductor patterns 2100, 2200 in the second in-plane direction D3 may be equal or different.

[0057] In this embodiment, the conductor patterns 2100 and 2200 are provided in place of the conductive patterns PT2 and PT3, but the insulating substrate 2000 may have both. Furthermore, the conductive patterns PT2 and PT3 themselves may be configured to function as the conductor patterns 2100 and 2200. Also, the shape of the conductor patterns 2100 and 2200 is not limited to rectangles but is arbitrary, and is not limited to planar shapes but may be three-dimensional.

[0058] Additionally or alternatively, the thermal induction portion 2000b may include thermal barrier portions 2300, 2400 that block the heat flux from the element 3000. The thermal conductivity of the thermal barrier portions 2300, 2400 is lower than that of the insulating substrate 2000. For example, the thermal barrier portions 2300, 2400 may be openings that penetrate the insulating substrate 2000. The thermal barrier portions 2300, 2400 are not limited to through-openings and may be formed in the shape of grooves.

[0059] The thermal barriers 2300 and 2400 are provided in regions where the heat flux transmitted on the insulating substrate 2000 via conductive patterns (in this embodiment, the conductor patterns 2100 and 2200 also function as conductive patterns) (for example, in the first in-plane direction D2) is transmitted through the insulating substrate 2000 without passing through the first outer lead 31 and inner leads 40 and 45, which act as transmission parts. In this embodiment, the thermal barriers 2300 and 2400 are positioned apart between the conductor patterns 2100 and 2200 in the first in-plane direction D2, in a direction (for example, the second in-plane direction D3) that intersects the direction in which the heat flux is transmitted on the insulating substrate 2000 (first in-plane direction D2). As a result, a region SP1 is defined on the main surface 2000a, surrounded by the conductor patterns 2100, 2200 and the thermal barrier sections 2300, 2400, and the heat flux measuring device 1 is placed on this region SP1. This makes it possible to suppress the heat flux from flowing in a way that bypasses the heat flux measuring device 1. The conductor patterns 2100, 2200 described above may extend to the first in-plane direction D2 of the thermal barrier sections 2300, 2400. With such a configuration, it is possible to further suppress the heat flux from bypassing the heat flux measuring device 1.

[0060] 3. The above embodiments are merely examples and are not limited thereto. For example, the above embodiments may be implemented in the following ways as appropriate.

[0061] The specific structure of the heat flux measuring device 1 is arbitrary and not limited to the various embodiments described above, and in particular, a structure similar to the wiring structure of existing semiconductor devices can be adopted.

[0062] In the embodiments described above, a lead frame 46 was used, but other substrates may also be used.

[0063] The heat flux sensor 43 described above is not limited to one configured to output a thermoelectric voltage based on an abnormal Nernst effect, but may also be configured to output a thermoelectric voltage based on the Seebeck effect.

[0064] The above embodiment can also be provided as a heat flux measurement method using a heat flux measurement system 1000. The heat flux measurement method includes introducing a heat flux along the main surface 2000a of the insulating substrate 2000 via conductive patterns PT2 and PT3 on the insulating substrate 2000 toward a heat flux sensor 43 mounted on the insulating substrate 2000, and guiding the heat flux introduced along the main surface 2000a toward the heat flux sensor 43 in a direction D1 perpendicular to the surface, thereby causing the heat flux sensor 43 to output a total electromotive force V1 as an electrical signal.

[0065] The above embodiments may also be provided in the following embodiments.

[0066] (1) A heat flux measurement system that can be mounted on an insulating substrate, wherein the insulating substrate has a main surface on which elements can be arranged and a conductive pattern having electrical conductivity on the main surface, the heat flux measurement system comprises a transmission unit and at least one heat flux sensor, the transmission unit comprises a connection unit that can be thermally connected to the conductive pattern of the insulating substrate and an extension unit that extends from the connection unit along the main surface, the heat flux sensor is thermally connected to the extension unit and is configured to output an electrical signal based on the component of the heat flux generated by heat exchange with the extension unit that is perpendicular to the main surface.

[0067] (2) The heat flux measurement system described in (1) above, wherein the heat flux sensor includes a noncollinear antiferromagnetic material having an easy magnetization axis along an in-plane direction perpendicular to the direction perpendicular to the plane, and the heat flux measurement system comprises a magnetic field application unit, the magnetic field application unit is configured to apply a magnetic field along the in-plane direction to the antiferromagnetic material.

[0068] (3) The heat flux measurement system described in (2) above, wherein the magnetic field application unit includes a ferromagnetic material located perpendicular to the surface of the heat flux sensor, and the easy magnetization axis of the ferromagnetic material is aligned with the easy magnetization axis of the antiferromagnetic material.

[0069] (4) A heat flux measurement system according to (2) or (3) above, wherein the heat flux sensor is a plurality of heat flux sensors, the plurality of heat flux sensors have different polarities and are arranged in line in the in-plane direction, and the magnetic field application unit is configured to apply magnetic fields opposite to each of the plurality of heat flux sensors.

[0070] (5) A heat flux measurement system according to any one of (1) to (4) above, wherein the heat flux sensor is provided with a plurality of output terminals, the plurality of output terminals are configured to output the electrical signal, and the transmission unit is connected to at least one of the plurality of output terminals.

[0071] (6) A heat flux measurement system according to any one of (1) to (5) above, wherein the heat flux sensor comprises a first surface and a second surface located opposite each other in the direction perpendicular to the surface, and is configured to output an electrical signal based on the heat flux between the first surface and the second surface, and the first surface is connected to the transmission section such that it overlaps with at least a part of the transmission section when the heat flux sensor is viewed in plan from the direction perpendicular to the surface.

[0072] (7) The heat flux measurement system described in (6) above, wherein the transmission unit comprises a first transmission unit and a second transmission unit, the first transmission unit and the second transmission unit are configured to be connectable to different conduction patterns, the first transmission unit is connected to the first surface, and the second transmission unit is connected to the second surface.

[0073] (8) A heat flux measurement system according to any one of (1) to (7) above, further comprising a heat sink, wherein the heat sink is thermally connected to the element and the heat flux sensor so as to cover them from a direction perpendicular to the surface.

[0074] (9) A heat flux measurement system according to any one of (1) to (8) above, further comprising an insulating substrate, wherein the insulating substrate comprises a heat induction section, and the heat induction section is configured to preferentially transmit the heat flux from an in-plane direction along the main surface of the insulating substrate toward the heat flux sensor.

[0075] (10) A system in which the heat flux measurement system described in (9) above includes a conductor pattern using a thermal conductor electrically insulated from the element.

[0076] (11) A heat flux measurement system according to (9) or (10) above, wherein the heat induction section includes a heat blocking section that blocks the heat flux, and the heat blocking section is provided in a region where the heat flux transmitted on the insulating substrate is transmitted through the insulating substrate without passing through the transmission section.

[0077] (12) The heat flux measurement system described in (11) above, wherein the heat shield is an opening that penetrates the insulating substrate.

[0078] (13) A method for measuring heat flux using a heat flux measuring system described in any one of (1) to (12) above, comprising: introducing a heat flux along the main surface via a conductive pattern on the insulating substrate toward a heat flux sensor mounted on the insulating substrate; and guiding the heat flux introduced along the main surface toward the heat flux sensor in a direction perpendicular to the surface, thereby causing the heat flux sensor to output the electrical signal. Of course, this is not limited to this method.

[0079] Finally, while various embodiments relating to this disclosure have been described, these are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0080] 1: Heat flux measuring device, 2: Housing, 3: Outer lead, 31: First outer lead, 32: Second outer lead, 4: Internal circuit, 40: Inner lead, 41: Adhesive layer, 42: Substrate layer, 43: Heat flux sensor, 43a: First surface, 43b: Second surface, 43c: First heat flux sensor, 43d: Second heat flux sensor, 431: Thermoelectric conversion element, 432: Wiring, 433: Output terminal, 44: Conductive wire, 45: Inner lead, 45a: Heat conduction part, 45b: Base part, 46: Lead frame, 47: Thermal coupling part, 48: 5: Conductor, 6: Heat sink, 6: Magnetic field application section, 6a: First magnetic field application section, 6b: Second magnetic field application section, 1000: Heat flux measurement system, 2000: Insulating substrate, 2000a: Main surface, 2000b: Thermal induction section, 2100: Conductor pattern, 2200: Conductor pattern, 2300: Thermal insulation section, 2400: Thermal insulation section, 3000: Element, 4000: Signal processing section, D1: Direction perpendicular to the plane, D2: First in-plane direction, D3: Second in-plane direction, M: Magnetization, PT1 to PT5: Conduction pattern, SP1: Region, V1: Total electromotive force, V2: Total electromotive force

Claims

1. A heat flux measurement system that can be mounted on an insulating substrate, wherein the insulating substrate has a main surface on which elements can be arranged and a conductive pattern having electrical conductivity on the main surface, the heat flux measurement system comprises a transmission unit and at least one heat flux sensor, the transmission unit comprises a connection unit that can be thermally connected to the conductive pattern of the insulating substrate and an extension unit that extends from the connection unit along the main surface, the heat flux sensor is thermally connected to the extension unit and is configured to output an electrical signal based on the component of the heat flux generated by heat exchange with the extension unit that is perpendicular to the main surface.

2. A heat flux measurement system according to claim 1, wherein the heat flux sensor includes a noncollinear antiferromagnetic material having an easy magnetization axis along an in-plane direction perpendicular to the direction perpendicular to the plane, the heat flux measurement system comprises a magnetic field application unit, and the magnetic field application unit is configured to apply a magnetic field along the in-plane direction to the antiferromagnetic material.

3. A heat flux measurement system according to claim 2, wherein the magnetic field application unit includes a ferromagnetic material located perpendicular to the surface of the heat flux sensor, and the easy magnetization axis of the ferromagnetic material is aligned with the easy magnetization axis of the antiferromagnetic material.

4. A heat flux measurement system according to claim 2 or 3, wherein the heat flux sensor is a plurality of heat flux sensors, the plurality of heat flux sensors have different polarities and are arranged in line in the in-plane direction, and the magnetic field application unit is configured to apply magnetic fields opposite to each of the plurality of heat flux sensors.

5. A heat flux measurement system according to any one of claims 1 to 4, wherein the heat flux sensor comprises a plurality of output terminals, the plurality of output terminals are configured to output the electrical signal, and the transmission unit is connected to at least one of the plurality of output terminals.

6. A heat flux measurement system according to any one of claims 1 to 5, wherein the heat flux sensor comprises a first surface and a second surface located opposite each other in the direction perpendicular to the surface, and is configured to output an electrical signal based on the heat flux between the first surface and the second surface, and the first surface is connected to the transmission section such that it overlaps with at least a portion of the transmission section when the heat flux sensor is viewed in plan from the direction perpendicular to the surface.

7. A heat flux measuring system according to claim 6, wherein the transmission unit comprises a first transmission unit and a second transmission unit, the first transmission unit and the second transmission unit are configured to be connectable to different conduction patterns, the first transmission unit is connected to the first surface, and the second transmission unit is connected to the second surface.

8. A heat flux measurement system according to any one of claims 1 to 7, further comprising a heat sink, wherein the heat sink is thermally connected to the element and the heat flux sensor so as to cover them from a direction perpendicular to the surface.

9. A heat flux measurement system according to any one of claims 1 to 8, further comprising the insulating substrate, wherein the insulating substrate comprises a heat induction portion, and the heat induction portion is configured to preferentially transmit the heat flux from an in-plane direction along the main surface of the insulating substrate toward the heat flux sensor.

10. A heat flux measurement system according to claim 9, wherein the heat induction section includes a conductor pattern using a heat conductor electrically insulated from the element.

11. A heat flux measurement system according to claim 9 or 10, wherein the heat induction section includes a heat blocking section that blocks the heat flux, and the heat blocking section is provided in a region where the heat flux transmitted on the insulating substrate is transmitted through the insulating substrate without passing through the transmission section.

12. A heat flux measurement system according to claim 11, wherein the heat shield is an opening that penetrates the insulating substrate.

13. A method for measuring heat flux using a heat flux measuring system according to any one of claims 1 to 12, comprising: introducing a heat flux along the main surface via a conductive pattern on the insulating substrate toward a heat flux sensor mounted on the insulating substrate; and guiding the heat flux introduced along the main surface toward the heat flux sensor in a direction perpendicular to the surface, thereby causing the heat flux sensor to output the electrical signal.

Images