JP2005227180A - Infrared detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniaturized and inexpensive infrared detector which can detect incident infrared rays from different directions and which is packaged. <P>SOLUTION: The infrared detector 100 is packaged, wherein a plurality of sensor chips 10t<SB>1</SB>and 10t<SB>2</SB>which are housed in a case consisting of a cap 40 with a stem 30 and filters 40fa and 40fb, as a window for transmitting the infrared rays and in which infrared detection elements for sensing the infrared rays are formed are accommodated. In the infrared detector 100, the incident infrared rays L1 and L2 transmitted through the window from the different directions are detected by the plurality of sensor chips 10t<SB>1</SB>and 10t<SB>2</SB>, respectively. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a packaged small infrared detector.

  A packaged small infrared detector is disclosed in, for example, Japanese Patent Laid-Open No. 2003-270047 (Patent Document 1).

  FIG. 9 is a schematic cross-sectional view of the infrared detector disclosed in Patent Document 1. As shown in FIG.

  In the infrared detector 90 shown in FIG. 9, a sensor element 91 that senses infrared rays and a circuit board 92 on which a signal processing circuit that processes an output signal of the sensor element 91 is formed are formed separately. The sensor element 91 includes a membrane part 91a and a thick part 91b formed as a thin part, a hot junction of a thermocouple (not shown) is disposed on the membrane part 91a, and a cold junction of the thermocouple is a thick part 91b. Is placed on top. The sensor element 91 having such a membrane portion 91a is capable of highly sensitive infrared detection because the heat of the hot junction that is the infrared detection portion does not easily escape to the thick portion 91b side.

In the infrared detector 90, the sensor element 91 is disposed on the circuit board 92 and is housed in a case made up of a stem 93, a cap 94 and a filter 95. As described above, the infrared detector 90 in which the sensor element 91 and the circuit board 92 are stacked can be downsized as compared with the infrared detector in which the sensor element 91 and the circuit board 92 are arranged side by side.
JP 2003-270047 A

  If the infrared detector 90 shown in FIG. 9 is used to detect infrared rays incident from different directions, the infrared detectors 90 are prepared in the number of detection directions and arranged in each direction, or one infrared ray is detected. It is necessary to scan the detector 90 in each detection direction. However, in either case, the entire detector becomes larger and the cost of the entire detector increases.

  Accordingly, an object of the present invention is to provide a packaged small and inexpensive infrared detector capable of detecting infrared rays incident from different directions.

  The infrared detector according to claim 1 is a packaged infrared detector in which a plurality of sensor chips each having an infrared detection element for sensing infrared rays are housed in a case provided with a window that transmits infrared rays. An infrared ray that is transmitted through the window and incident from a different direction is detected by the plurality of sensor chips.

  In the infrared detector, the window and the sensor chip can be arranged so that infrared rays that are transmitted through a window provided in the case and incident from different directions are irradiated to the infrared detection elements of the corresponding sensor chip. . Thereby, it can be set as the infrared detector which can detect the infrared rays which permeate | transmit the window and enter from a different direction. In addition, the infrared detector can be reduced in size as compared with the case where infrared detectors are prepared in the number of detection directions or the infrared detectors are scanned, and the cost of the entire detector can be reduced. Can also be reduced. Therefore, the infrared detector can detect infrared rays incident from different directions, and can be a packaged small and inexpensive infrared detector.

  The infrared detector according to claim 2 includes an incident control unit that controls an incident direction of infrared rays, and the plurality of sensor chips transmit the window through the incident control unit, respectively, so as to be in different directions. It is characterized in that infrared rays incident from are detected.

  In the infrared detector, by using the incident control means, it is possible to more reliably select the infrared ray in the direction of detection, and it is possible to detect infrared rays incident from different directions with high accuracy.

  The incident control means may be a prism as described in claim 3. Moreover, it can also be set as a light-shielding plate. Furthermore, as described in claim 5, a reflecting plate may be used. These incident control means are all small components and can be packaged together with a plurality of sensor chips.

  7. The infrared detector according to claim 6, wherein the infrared detector includes a circuit chip on which an input / output control circuit for the sensor chip is formed, and the circuit chip is accommodated in the package. It is preferable. As a result, as compared with the case where the sensor chip and the circuit chip are provided in separate packages, the entire detector can be reduced in size, and the cost of the entire detector can be reduced.

  According to a seventh aspect of the present invention, in the infrared detector, each input / output control circuit corresponding to each of the plurality of sensor chips is preferably formed in one circuit chip. As a result, the entire detector can be downsized and the cost of the entire detector can be reduced as compared with the case where individual circuit chips corresponding to each sensor chip are provided.

  The sensor chip is preferably stacked on the circuit chip. As a result, as compared with the case where the sensor chip and the circuit chip are arranged side by side, the entire detector can be reduced in size, and the cost of the entire detector can be reduced.

  As described in claim 9, it is preferable that the incident control means is accommodated in the package. According to this, since the incident control means is not exposed to the outside, maintenance of the incident control means becomes easy.

  The infrared detector according to claim 10, wherein the sensor chip includes a substrate having a membrane formed as a thin portion, and the infrared detection element includes a thermocouple formed on the substrate and an infrared ray. An absorptive film, a hot junction of the thermocouple is formed on the membrane, a cold junction of the thermocouple is formed on a substrate outside the membrane, and the infrared absorbing film covers the hot junction When the infrared detection element receives infrared rays, the electromotive force of the thermocouple is changed by a temperature difference generated between the hot junction and the cold junction in the thermocouple, and the changed electromotive force is generated. It is suitable for an infrared detector that detects infrared rays based on electric power.

  The sensor chip having the membrane as described above is capable of highly accurate infrared detection because the heat at the hot junction of the thermocouple does not easily escape to the substrate side. By packaging a plurality of such high-precision sensor chips together with the incident control means, it is possible to detect infrared rays incident from different directions with high accuracy. Therefore, the infrared detector is a packaged small and inexpensive infrared detector, and can be a highly accurate infrared detector.

  In the infrared detection element according to claim 11, the thermocouple includes a plurality of sets of films made of different materials alternately extending in series on a substrate, and every other junction is connected to the hot junction. A so-called thermopile type infrared detecting element serving as a cold junction is preferable.

  The thermopile type infrared detection element can obtain a large sensor output and has high sensitivity. By packaging a plurality of sensor chips on which such highly sensitive infrared detecting elements are formed together with the incident control means, it is possible to detect infrared rays incident from different directions with high sensitivity. Therefore, the infrared detector is a packaged small and inexpensive infrared detector, and can be a highly sensitive infrared detector.

  Preferably, the substrate is a semiconductor substrate, and the infrared detection element is formed on the semiconductor substrate via an insulating film. By using a semiconductor substrate, a substrate having a membrane can be easily formed by a general semiconductor manufacturing technique, and a sensor chip having a membrane can be manufactured at low cost.

The formation of the membrane in the semiconductor substrate is, for example, as described in claim 13,
The semiconductor substrate may be etched from the back side opposite to the surface on which the infrared detection element is formed to form a membrane. For example, as described in claim 14, the semiconductor substrate may be etched from the same main surface side as the surface on which the infrared detection element is formed to form a membrane.

The best mode for carrying out the present invention will be described below with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic cross-sectional view of an infrared detector 100 in the present embodiment.

An infrared detector 100 shown in FIG. 1 includes two sensor chips 10t ₁ and 10t _{2 on} which infrared detection elements are formed, and two circuit chips 20t on which a control circuit for controlling input / output of the infrared detection elements is formed. ₁ and 20t ₂ . The sensor chips 10t ₁ and 10t ₂ are arranged on the circuit chips 20t ₁ and 20t ₂ in a stacked manner, and these are placed in a case made up of a cap 40 with a stem 30 and filters 40fa and 40fb which are windows that transmit infrared rays. Contained and packaged. The stem 30 and the cap 40 are welded, and nitrogen is enclosed in the case.

The two sensor chips 10t ₁ and 10t ₂ and the two circuit chips 20t ₁ and 20t ₂ in FIG. ₁ have the same structure.

  FIG. 2 shows details of the sensor chip. FIG. 2A is a schematic cross-sectional view of the sensor chip 10t, and FIG. 2B is a schematic top view. FIG. 2C is a schematic diagram showing the configuration of the infrared detection element 10 formed on the sensor chip 10t and the extraction of the sensor output.

  As shown in FIG. 2A, the sensor chip 10t is made of a silicon (Si) semiconductor substrate 1 and has a membrane 10m formed as a thin portion by etching from the back surface. An infrared detection element 10 is formed on the semiconductor substrate 1 with an insulating film 2 interposed therebetween. The infrared detection element 10 formed on the semiconductor substrate 1 includes a thermocouple 10a and an infrared absorption film 10b.

  As shown in FIG. 2B, the thermocouple 10a is disposed so as to surround the membrane 10m. In addition, in order to make it easy to see, illustration of the infrared rays absorption film 10b is abbreviate | omitted in FIG.2 (b) and FIG.2 (c).

  As shown in FIG. 2C, in the thermocouple 10a, a plurality of sets of films of different materials 10ax and 10ay are alternately extended in series on the semiconductor substrate 1 (thermopile), and every other junction is heated. It becomes the contact 10ah and the cold junction 10ac. As a combination of films of different materials 10ax and 10ay, for example, a combination of an aluminum film and a polysilicon film is used. As shown in FIGS. 2A and 2C, the hot junction 10ah of the thermocouple 10a is formed on a membrane 10m having a small heat capacity. On the other hand, the cold junction 10ac of the thermocouple 10a is formed on the thick portion 10n having a large heat capacity outside the membrane 10m. Further, as shown in FIG. 2A, in the infrared detection element 10, an infrared absorption film 10b is formed on the membrane 10m so as to cover the hot junction 10ah.

  When infrared rays are irradiated from a human body or the like, the infrared rays are absorbed by the infrared absorption film 10b, and the temperature rises. As a result, the temperature of the hot junction 10ah disposed below the infrared absorption film 10b increases. On the other hand, the temperature of the cold junction 10ac serves as a reference point for temperature measurement because the thick portion 10n serves as a heat sink and the temperature does not increase. As described above, the infrared detecting element 10 changes the electromotive force of the thermocouple 10a due to the temperature difference generated between the hot junction 10ah and the cold junction 10ac when receiving infrared rays (seepec effect), and the changed electromotive force. Infrared detection based on Since the thermocouple 10a shown in FIG. 2 (c) is a thermopile, the sum of electromotive forces generated by the combination of the different materials 10ax and 10ay becomes the output of the infrared detecting element 10.

  The sensor chip 10t having the membrane 10m shown in FIGS. 2 (a) to 2 (c) allows heat at the hot junction 10ah of the thermocouple 10a to hardly escape to the thick portion 10n, and enables highly accurate infrared detection. Moreover, the thermocouple 10a which is a thermopile can obtain a large electromotive force (sensor output), and can be a highly sensitive and highly accurate infrared detection element.

The infrared detector 100 shown in FIG. 1 can detect infrared rays L1 and L2 that are transmitted through filters 40fa and 40fb, which are infrared transmission windows, and are incident from different directions. In the infrared detector 100, the infrared rays L0 indicated by the thick dotted arrows that pass through the filters 40fa and 40fb provided on the cap 40 and enter from above are applied to the sensor chips 10t ₁ and 10t ₂ as shown in the figure. Irradiated equally. On the other hand, the infrared rays L1 and L2 indicated by thick solid arrows that pass through the filters 40fa and 40fb and enter from different directions are irradiated to the infrared detection elements of the corresponding sensor chips 10t ₂ and 10t ₁ as shown in the figure. As described above, the arrangement of the filters 40fa and 40fb and the sensor chips 10t ₁ and 10t ₂ is appropriately set. In this manner, the infrared detector 100 in FIG. 1 is an infrared detector that can detect the infrared rays L1 and L2 that are transmitted through the filters 40fa and 40fb, which are infrared transmission windows, and are incident from different directions.

The infrared detector 100 in FIG. 1 can reduce the size of the entire detector as compared with the case where infrared detectors are prepared in the number of detection directions or the infrared detectors are scanned. Cost can also be reduced. In addition, the infrared detector 100 of FIG. 1 includes not only the sensor chips 10t ₁ and 10t ₂ but also circuit chips 20t ₁ and 20t ₂ in which input / output control circuits for the sensor chips 10t ₁ and 10t ₂ are formed. Contained and packaged. This also makes it possible to reduce the size of the entire detector and reduce the cost of the entire detector as compared with an infrared detector in which the sensor chip and the circuit chip are separately packaged. Further, in the infrared detector 100 of FIG. 1, sensor chips 10t ₁ and 10t ₂ and circuit chips 20t ₁ and 20t ₂ are stacked. Therefore, it is a miniaturized infrared detector as compared with an infrared detector in which all sensor chips and circuit chips are arranged side by side.

  As described above, the infrared detector 100 of FIG. 1 is capable of detecting the infrared rays L1 and L2 incident from different directions, and is a packaged small and inexpensive infrared detector.

  FIG. 3 shows a schematic cross-sectional view of another infrared detector 101. In addition, in the infrared detector 101 shown in FIG. 3, the same code | symbol was attached | subjected about the part similar to the infrared detector 100 of FIG.

In the infrared detector 101 of FIG. 3, each input / output control circuit corresponding to each of the _two sensor chips 10t ₁ and 10t ₂ is formed in one circuit chip 20t. As a result, the stem 31 and the cap 41 are smaller than the infrared detector 100 of FIG. 1 in which the individual circuit chips 20t ₁ and 20t ₂ corresponding to the sensor chips 10t ₁ and 10t ₂ are provided. The entire vessel is downsized. Moreover, the cost of the whole detector can be reduced by using one circuit chip 20t. Note that the infrared detector 101 shown in FIG. 3 can also detect infrared rays L1 and L2 that pass through the filters 40fa and 40fb and enter from different directions in the same manner as the infrared detector 100 shown in FIG.

  FIG. 4 shows a schematic cross-sectional view of another infrared detector 102. In addition, in the infrared detector 102 shown in FIG. 4, the same code | symbol was attached | subjected about the part similar to the infrared detector 101 of FIG.

Compared with the infrared detector 101 in FIG. 3, the infrared detector 102 in FIG. 4 has a shape of the cap 42 and the arrangement of the filters 40fa and 40fb, which are infrared transmission windows, with respect to the two sensor chips 10t ₁ and 10t ₂ . Is different. In the infrared detector 101 of FIG. 3, the ratio of the infrared rays L1 and L2 incident from the side is smaller than the infrared ray L0 incident from above. On the other hand, in the infrared detector 102 of FIG. 4, since the cap 42 is opened larger than the infrared rays L1 and L2 incident from the side, the infrared rays incident from the side with respect to the infrared ray L0 incident from above. The ratio of L1 and L2 becomes larger. Therefore, in the infrared detector 102 of FIG. 4, the influence of the infrared ray L0 incident from above is reduced, and the infrared rays L1 and L2 incident through different directions through the filters 40fa and 40fb can be detected more reliably.
(Second Embodiment)
The infrared detector according to the first embodiment is an infrared detector that detects infrared rays that are transmitted through a window provided in a case and incident from different directions. The present embodiment further relates to an infrared detector including an incident control means for controlling the incident direction of infrared rays. Hereinafter, the present embodiment will be described with reference to the drawings.

  5A and 5B are schematic cross-sectional views of the infrared detectors 103 and 104 in the present embodiment.

  Infrared detectors 103 and 104 shown in FIGS. 5A and 5B are incident control means for controlling the incident direction of infrared rays with respect to the infrared detector 100 in FIG. 1 and the infrared detector 101 in FIG. As an infrared detector to which prisms 50a and 50b are added. In FIGS. 5A and 5B, the illustration of the infrared ray L0 incident from above is omitted for simplicity.

In the infrared detectors 103 and 104 provided with the prisms 50a and 50b, as shown in the drawing, infrared rays L3 and L4 incident from different directions are refracted by the prisms 50a and 50b, and are transmitted to the sensor chips 10t ₁ and 10t ₂ . Irradiated. In the infrared detectors 103 and 104, by appropriately setting the apex angles of the prisms 50a and 50b, it is possible to more reliably select the infrared rays L3 and L4 in the direction to be detected. Thereby, the infrared rays L3 and L4 incident from different directions can be detected with high accuracy.

  In the infrared detectors 103 and 104 of FIGS. 5A and 5B, the prisms 50a and 50b are arranged outside the caps 40 and 41, but are arranged inside the caps 40 and 41. You may accommodate in a package. In this case, since the prisms 50a and 50b are not exposed to the outside, maintenance of the prisms 50a and 50b is facilitated.

  6A and 6B are schematic cross-sectional views of other infrared detectors 105 and 106 in the present embodiment.

  Infrared detectors 105 and 106 shown in FIGS. 6A and 6B are incident control means for controlling the incident direction of infrared rays with respect to the infrared detector 100 in FIG. 1 and the infrared detector 101 in FIG. As an infrared detector to which light shielding plates 60a and 60b are added.

In the infrared detectors 105 and 106 shown in FIGS. 6A and 6B, as shown in the drawing, the infrared rays L0 incident from above are blocked by the light shielding plates 60a and 60b, so that each of the sensor chips 10t ₁ and 10t _2. Is not irradiated. Therefore, in the infrared detectors 105 and 106, the influence of the infrared ray L0 incident from above can be eliminated, and the infrared rays L1 and L2 in the detection direction can be selected more reliably. Thereby, the infrared rays L1 and L2 incident from different directions can be detected with high accuracy.

  7A to 7C are schematic cross-sectional views of other infrared detectors 107 to 109 in the present embodiment.

  Infrared detectors 107 and 108 shown in FIGS. 7A and 7B are incident control means for controlling the incident direction of infrared rays with respect to the infrared detector 100 in FIG. 1 and the infrared detector 101 in FIG. As an infrared detector to which reflectors 70 and 71 are added. In FIGS. 7A and 7B, illustration of the infrared ray L0 incident from above is omitted for simplification.

The infrared detector 101 of an infrared detector 100 and 3 in Figure 1, infrared L1 transmitted through the filter 40fa is irradiated to the sensor chip 10t _2, infrared L2 which has passed through the filter 40fb has been irradiated to the sensor chip 10t ₁ . Infrared On the other hand, FIG. 7 in which a reflection plate 70, 71 (a), the infrared detector 107, 108 (b), the infrared L1 having passed through the filter 40fa is irradiated to the sensor chip 10t _1, passed through the filter 40fb L2 is irradiated on the sensor chip 10t _2.

  In the infrared detectors 107 and 108 provided with the reflection plates 70 and 71, the infrared rays L1 and L2 in the direction to be detected can be more reliably selected by appropriately setting the angles of the surfaces of the reflection plates 70 and 71. it can. As a result, the infrared rays L1 and L2 incident from different directions can be detected with high accuracy.

The infrared detector 109 shown in FIG. 7C includes three sensor chips 10t _{1 to} 10t ₃ and one circuit chip 21t. The three sensor chips 10t _{1 to} 10t ₃ are stacked on the circuit chip 21t, and are housed in a case made up of a cap 43 having a stem 32 and filters 40fa to 40fc which are windows that transmit infrared rays. And packaged. The infrared detector 109 of FIG. 7C is also provided with reflecting plates 72 and 73 as incident control means for controlling the incident direction of infrared rays.

In the infrared detector 109 of FIG. 7C, as shown in the figure, infrared rays L0 to L2 incident from three different directions can be detected. The surface of the sensor chip 10t ₂ side reflectors 72 and 73, to ensure the selection of an infrared L0 incident from above is coated so reflection does not occur in the infrared.

  The infrared detectors 103 to 109 of the present embodiment shown in FIGS. 5 to 7 include a prism, a light shielding plate, or a reflector as incident control means for controlling the incident direction of infrared rays, and through these incident control means. The infrared rays incident from different directions through the window are detected by the plurality of sensor chips. In the infrared detectors 103 to 109 of the present embodiment, by using the incident control means, it is possible to more reliably select the infrared ray in the direction to be detected, and it is possible to detect infrared rays incident from different directions with high accuracy. Become.

  In addition, incident control means such as a prism, a light shielding plate, and a reflecting plate are all small components, and can be housed in a case together with a plurality of sensor chips and packaged.

As described above, the infrared detectors 103 to 109 of the present embodiment shown in FIGS. 5 to 7 can detect infrared rays incident from different directions with high accuracy, and can be packaged in a small and inexpensive infrared detector. Can be a container. In addition, although the infrared detectors 103-109 shown in FIGS. 5-7 used the prism, the light-shielding plate, or the reflecting plate independently, you may use these in combination.
(Other embodiments)
The sensor chips 10t _{1 to} 10t ₃ in the infrared detectors 100 to 109 shown in FIGS. 1 to 7 are sensor chips in which a membrane is formed on a semiconductor substrate as shown in detail in FIG. Further, the membrane is formed by etching the semiconductor substrate from the back side opposite to the surface on which the infrared detection element is formed. However, the sensor chip used in the infrared detector of the present invention is not limited to this, and the membrane may be formed by etching the semiconductor substrate from the same main surface side as the surface on which the infrared detection element is formed.

FIGS. 8A to 8C are schematic cross-sectional views of the infrared detectors 110 to 112 of the present invention in which such sensor chips 11t ₁ and 11t ₂ are used.

  When a semiconductor substrate is used as the sensor chip on which the infrared detection element is formed, it is preferable because a membrane can be easily formed by a general semiconductor manufacturing technique and can be manufactured at a low cost. However, the sensor chip on which the infrared detection element is formed is not limited to this, and may be a substrate using any material such as glass. In order to obtain a highly sensitive infrared detection element, it is preferable to form a membrane on the substrate, but even a sensor chip having no membrane is effective. Further, the infrared detection element is not limited to the one using a thermocouple, but may be one that detects infrared rays by using a resistance value change due to the temperature of the thin film resistor.

It is a typical sectional view of the infrared detector in a 1st embodiment. It is a figure which shows the detail of a sensor chip, (a) is typical sectional drawing, (b) is a typical top view, (c) is a schematic which shows the structure of an infrared detection element, and extraction of a sensor output FIG. It is a typical sectional view of another infrared detector in a 1st embodiment. It is a typical sectional view of another infrared detector in a 1st embodiment. (A), (b) is typical sectional drawing of the infrared detector in 2nd Embodiment. (A), (b) is typical sectional drawing of another infrared detector in 2nd Embodiment. (A)-(c) is typical sectional drawing of another infrared detector in 2nd Embodiment. (A)-(c) is typical sectional drawing of the infrared detector in other embodiment. It is typical sectional drawing of the conventional infrared detector.

Explanation of symbols

90,100～112 infrared detector _{10t, 10t 1 ~10t 3, 11t} 1, 11t 2 sensor chip 1 semiconductor substrate 2 insulating film 10 infrared detector 10m membrane 10n thick portion 10a thermocouple 10ah hot junction 10ac cold junction 10b infrared absorbing film _{20t, 21t, 20t 1, 20t} 2 circuit chip 30 to 32 stems 40-43 cap 40fa, 40fb, 40fc filter 50a, 50b prism 60a, 60b light shielding plate 70-73 reflector L0, L1, L2 infrared

Claims (14)

A packaged infrared detector in which a plurality of sensor chips each formed with an infrared detection element for sensing infrared rays are housed in a case provided with a window that transmits infrared rays,
An infrared detector, wherein the plurality of sensor chips respectively detect infrared rays that are transmitted through the window and incident from different directions. The infrared detector comprises an incident control means for controlling the incident direction of infrared rays,
2. The infrared detector according to claim 1, wherein infrared rays that are transmitted through the window and incident from different directions are detected by the plurality of sensor chips via the incident control unit.   The infrared detector according to claim 2, wherein the incident control means is a prism.   The infrared detector according to claim 2, wherein the incident control means is a light shielding plate.   The infrared detector according to claim 2, wherein the incident control means is a reflector. The infrared detector is
An infrared detector comprising a circuit chip on which an input / output control circuit of the sensor chip is formed,
The infrared detector according to claim 1, wherein the circuit chip is housed in the package.   The infrared detector according to claim 6, wherein each input / output control circuit corresponding to each of the plurality of sensor chips is formed in one circuit chip.   The infrared detector according to claim 6 or 7, wherein the sensor chip is stacked on the circuit chip.   The infrared detector according to claim 6, wherein the incident control unit is accommodated in the package. The sensor chip is composed of a substrate having a membrane formed as a thin part,
The infrared detection element comprises a thermocouple and an infrared absorption film formed on the substrate,
A hot junction of the thermocouple is formed on the membrane, and a cold junction of the thermocouple is formed on a substrate outside the membrane;
The infrared absorbing film is formed on the membrane so as to cover the hot junction;
When the infrared detection element receives infrared rays, the electromotive force of the thermocouple is changed by a temperature difference generated between a hot junction and a cold junction in the thermocouple, and infrared rays are detected based on the changed electromotive force. The infrared detector according to any one of claims 1 to 9, wherein   11. The thermocouple according to claim 10, wherein a plurality of sets of films of different materials are alternately extended in series on the substrate, and every other junction becomes the hot junction and the cold junction. Infrared detector. The substrate is a semiconductor substrate;
The infrared detector according to claim 10, wherein the infrared detection element is formed on the semiconductor substrate via an insulating film. The semiconductor substrate is etched from the back side opposite to the surface on which the infrared detection element is formed,
The infrared detector according to claim 12, wherein the membrane is formed. The semiconductor substrate is etched from the same main surface side as the surface on which the infrared detection element is formed,
The infrared detector according to claim 12, wherein the membrane is formed.

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