JP2015190912A - Infrared detection device, visual field limiting unit, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared detection device capable of more accurately determining the quantity of infrared rays outputted from an external visual field, a visual field limiting unit, and a manufacturing method thereof.SOLUTION: The infrared detection device includes: a sensor unit 10 which has a quantum type infrared sensor part 11 on a first principal surface thereof; and a visual field limiting unit 20 which has an aperture 23 for limiting a visual field of the quantum type infrared sensor part 11 and is provided on the first principal surface of the sensor unit 10 so that the quantum type infrared sensor part 11 is optically connected to the outside via the aperture 23. The visual field limiting unit 20 includes a first member 21 having emissivity of 0.7 or more at 25°C and a second member 22 having emissivity of 0.3 or less at 25°C. An inside wall part 201 of the aperture 23 of the visual field limiting unit 20 is made of the first member 21. The second member 22 is exposed to a surface parallel with the first principal surface of the sensor unit 10, out of an external surface of the visual field limiting unit 20.

Description

  The present invention relates to an infrared detection device, a visual field limiting unit, and a method for manufacturing the same.

Sensors are known that convert physical changes such as temperature, pressure, and light into electrical changes such as current and voltage. With this sensor, various objects can be measured as numerical values. In particular, sensors that can contribute to energy saving and high efficiency are attracting attention due to recent interest in environmental issues.
Among these sensors, an optical sensor that detects the amount of change in light includes an infrared sensor that receives infrared rays and converts them into electrical signals. Infrared sensors are used for TV remote control operations and the like because they can transmit information without affecting the human eye.

  Furthermore, the infrared sensor has a feature that it can sense the temperature of an object without directly contacting it, and can be used as a human sensor or a non-contact thermometer that senses a heat source such as a human body. For this reason, when using an infrared sensor, for example as a human sensor, unnecessary electric power can be effectively reduced by mounting in an illumination etc. In addition, for a gas having an absorption band in the infrared region (carbon dioxide, carbon monoxide, etc.), the infrared sensor can be applied as a gas sensor, and various uses beyond a human sensor can be expected. Infrared sensors are classified into thermal sensors and quantum sensors based on their operating principles.

Thermal sensors are widely used in human sensors, but have a problem of low frequency response. Further, when the thermal sensor is used as a gas sensor, the gas detection response is low, and there is a problem in terms of rapid abnormality detection.
On the other hand, the quantum type sensor is characterized by high frequency response, and is very promising compared to the thermal type sensor.
Moreover, in order that an infrared sensor shall output the signal according to the infrared rays which injected from the predetermined visual field range, the form which provides a visual field restriction | limiting part is known (patent document 1).

JP 2011-95143 A

As shown in Patent Document 1, in a conventional infrared detection device having a quantum infrared sensor unit and a field-of-view restriction unit, the correct amount of infrared rays may not be accurately quantified using the output signal of the quantum infrared sensor unit. .
Therefore, the present invention has been made in view of such circumstances, and provides an infrared detection device, a visual field limiting unit, and a method for manufacturing the same, which can quantify the amount of infrared light output from an external visual field with higher accuracy. The purpose is to do.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by the following aspects.
That is, an infrared detection device according to an aspect of the present invention includes a sensor unit having a quantum infrared sensor unit on a first main surface side, and an opening that restricts a field of view of the quantum infrared sensor unit. And a visual field limiting unit provided on the first main surface of the sensor unit so that the infrared sensor unit is optically connected to the outside through the opening, and the visual field limiting unit is 25 ° C. A first member having an emissivity of 0.7 or more and a second member having an emissivity at 25 ° C. of 0.3 or less, and the inner wall portion of the opening of the visual field limiting unit is the first member. And the second member is exposed on a surface parallel to the first main surface of the sensor unit, of the outer surface of the visual field limiting unit.

  Moreover, the visual field restriction unit according to an aspect of the present invention includes an opening for restricting the visual field of the quantum infrared sensor unit of the sensor unit having the quantum infrared sensor unit on the first main surface side, and 25 ° C. A first member having an emissivity of 0.7 or more and a second member having an emissivity at 25 ° C. of 0.3 or less, and an inner wall portion of the opening is made of the first member, and the visual field When the limiting unit is mounted on the first main surface of the sensor unit, the second member is exposed on a surface parallel to the first main surface of the sensor unit, of the outer surface of the visual field limiting unit. It is characterized by.

  The manufacturing method of the visual field restriction unit according to one aspect of the present invention includes a second member disposing step of disposing a second member having an opening region on a support member, covering the second member, and one on the opening region. A first member forming step of forming a first member on the support member so that an optical opening is formed in the portion, and the first member has an emissivity at 25 ° C. of 0.7 or more. A material having an emissivity at 25 ° C. of 0.3 or less is used for the second member.

  An infrared detection device according to another aspect of the present invention includes a sensor unit having a quantum infrared sensor unit on a first main surface side, an opening that limits a field of view of the quantum infrared sensor unit, and the quantum type A visual field limiting unit provided on the first main surface of the sensor unit so that an infrared sensor unit is optically connected to the outside through the opening, and the visual field limiting unit is at 25 ° C. The first member having an emissivity of 0.7 or more and the second member having an emissivity at 25 ° C. of 0.3 or less, and the inner wall portion of the opening of the visual field limiting unit is the first member The second member is exposed in at least a part of a region surrounding the opening in a plan view on the outer surface of the visual field limiting unit.

  According to the infrared detection device of the present invention, it is possible to accurately quantify the amount of infrared light output from the external visual field using the output signal of the quantum infrared sensor unit.

It is a figure which shows the structural example of the infrared rays detection apparatus 100 which concerns on 1st Embodiment. It is a figure for demonstrating the effect of the infrared detection apparatus 100 which concerns on 1st Embodiment. It is an external appearance schematic diagram which shows the structural example of the infrared rays detection apparatus 200 which concerns on 2nd Embodiment. It is a schematic diagram for demonstrating the manufacturing method of the visual field restriction | limiting unit 20 which concerns on embodiment to process order. It is a figure which shows the structural example of the infrared sensor unit 500 used for verification. It is a figure which shows the structural example of the infrared sensor unit 500 used for verification. It is a figure which shows the structural example of the infrared sensor unit 500 used for verification. It is a figure which shows the state which installed the aluminum tape 61 in the 1st infrared sensor unit for verification 600. FIG. It is a figure which shows the state which installed the aluminum tape 61 in the 1st infrared sensor unit for verification 600. FIG. It is a figure which shows the state which installed the aluminum tape 61 in the 1st infrared sensor unit for verification 600. FIG. It is a figure which shows the state which has arrange | positioned the 1st verification infrared sensor unit 600 facing the planar blackbody furnace. It is a figure which shows the structural example of the infrared sensor unit 700 for 2nd verification. It is a figure which shows the structural example of the infrared sensor unit 700 for 2nd verification. It is a figure which shows the structural example of the infrared sensor unit 700 for 2nd verification. It is a figure which shows the state which has arrange | positioned the 2nd verification infrared sensor unit 700 facing the plane blackbody furnace.

Hereinafter, a mode for carrying out the present invention (this embodiment) will be described.
<Infrared detector>
The infrared detection device of the present embodiment has a sensor unit having a quantum infrared sensor unit on the first main surface side, and an opening that restricts the visual field of the infrared sensor unit, and the quantum infrared sensor unit is interposed through the opening. And a visual field limiting unit provided on the first main surface of the sensor unit so as to be optically connected to the outside. The visual field limiting unit includes a first member having an emissivity of 0.7 or more at 25 ° C. and a second member having an emissivity of 25 or less at 25 ° C. The inner wall portion of the opening of the visual field limiting unit is the first member. The second member is exposed on a surface parallel to the first main surface of the sensor unit.
In the infrared detection device of the present embodiment, the inner wall portion of the opening of the field limiting unit is the first member, and the second member of the field limiting unit is exposed on the outer surface parallel to the first main surface of the sensor unit. As a result, the amount of infrared rays output from the external visual field can be quantified with high accuracy.

(Description of mechanism)
As a mechanism that enables the infrared detection device of the present embodiment to quantify the amount of infrared rays output from the measurement object with high accuracy, the second member of the field-of-view restriction unit is arranged outside the first main surface of the sensor unit. By being exposed on the surface, the infrared rays output from the measurement object toward the outer surface of the visual field limiting unit are reflected without being absorbed by the second member, so that the temperature change of the visual field limiting unit is suppressed. It is inferred that this is due to this.

  This will be described in detail. First, a quantum type infrared sensor part outputs the signal according to the difference of the infrared energy input from the outside, and the infrared energy which quantum type infrared sensor part itself outputs. In the infrared detection device of the present embodiment, the infrared energy source input from the outside to the quantum infrared sensor section is an external visual field outside the opening and an inner wall (internal visual field) of the opening of the visual field limiting unit. As described above, in the infrared detection device of the present embodiment, since the temperature change of the visual field limiting unit is suppressed, the influence of the infrared energy of the internal visual field is reduced, the infrared energy input from the outside, and the quantum infrared sensor unit The difference in the infrared energy output by itself is due to the infrared energy input from the external visual field. For this reason, it is surmised that the infrared detection apparatus of this embodiment can quantify the amount of infrared rays output from the external visual field with high accuracy.

In the infrared detection device of the present embodiment, the quantum infrared sensor unit may include a plurality of light receiving units, and each of the plurality of light receiving units may independently output a signal.
In the conventional infrared detecting device, in which the quantum infrared sensor unit is composed of a plurality of light receiving units and is not exposed on the outer surface parallel to the first main surface of the sensor unit, the opening of the field limiting unit among the fields of view of each light receiving unit When the areas of the inner wall portions are different, it is more difficult to quantify the amount of infrared rays output from the external visual field. That is, when the temperature of the visual field limiting unit and that of the quantum infrared sensor unit are different, the variation in the output becomes more remarkable.
In the infrared detection device of the present embodiment, even when the quantum infrared sensor unit has a plurality of light receiving units, the temperature change of the visual field limiting unit is suppressed as described above, so the amount of infrared light output by the external visual field is reduced. It becomes possible to quantify with high accuracy in each light receiving part.

As described above, the amount of infrared rays output from the external visual field can be quantified with high accuracy in each light receiving unit. For this reason, when a measurement object having a known uniform temperature is installed in each light receiving unit over the entire external visual field of each light receiving unit, the signals output from each light receiving unit have the same value. Set correction conditions (gain correction value, offset correction value, etc.) for the output signal. Accordingly, it is possible to obtain a more accurate correction condition that cancels the characteristic variation of each light receiving unit due to manufacturing variation or the like. At this time, since the influence of the infrared energy of the internal visual field causes an error of the gain correction value, it is necessary to reduce the influence of the infrared energy of the internal visual field.
In order to internally execute and output such correction conditions for the output signal from the quantum infrared sensor unit, the infrared detection device of the present embodiment receives the output signal from the quantum infrared sensor unit. It is preferable to further include a signal correction unit that corrects and outputs the output signal.

(View restriction unit)
The field-of-view restriction unit of the present embodiment has an opening and has a first member and a second member. The inner wall part of the opening part of the visual field restriction unit is a first member. The second member of the visual field restriction unit is exposed on the outer surface. The first member is made of a material having an emissivity at 25 ° C. of 0.7 or more, and examples thereof include an epoxy resin and a polyphthalamide resin. The second member is made of a material having an emissivity at 25 ° C. of 0.3 or less from the viewpoint of reflecting infrared rays incident from the outside without absorbing them, for example, aluminum (Al), copper (Cu), or Cu Etc. as the main material, and a metal or the like whose surface is plated. Examples of the plating include nickel (Ni) plating and tin (Sn) plating.

  In the visual field limiting unit, the inner wall portion of the opening is the first member. Further, the second member of the visual field limiting unit is exposed on the outer surface. The field-of-view restriction unit is spatially connected to the outside through the opening on the first main surface of the sensor unit having the quantum infrared sensor unit on the first main surface side. Installed. Thereby, as above-mentioned, the infrared rays detection apparatus which can quantify the amount of infrared rays which a measurement object outputs with high precision can be obtained.

  In addition, as long as the opening part of the opening part of a visual field restriction | limiting part optically connects a quantum type infrared sensor part and the exterior, the light transmittance etc. will not be restrict | limited in particular. For example, an optical filter having a high transmittance at a specific wavelength in part or all of the aperture, an optical lens that changes the optical path of infrared light incident from the external field, and a reflection that prevents reflection of infrared light incident from the external field An optical adjustment unit such as a prevention film may be provided. The shape of the opening is not particularly limited. Examples of the shape of the opening in plan view include a polygon such as a triangle and a quadrangle, and an oval shape such as a circle and an ellipse.

Moreover, it is preferable that the thickness of a metal part is 500 micrometers or less from a viewpoint of the ease of manufacture of a 2nd member. Here, the thickness means a thickness in a direction perpendicular to the first main surface of the sensor unit. As an example for realizing the second member, a so-called lead frame having Cu as a main material can be used. In this embodiment, the 2nd member should just be exposed to at least one part of the outer surface parallel to the 1st main surface of a sensor unit among the outer surfaces of a visual field restriction unit. From the viewpoint of improving the measurement accuracy of the infrared detector, 50% or more of the outer surface parallel to the first main surface is preferably the second member, more preferably 70% or more, and 90% or more. Is more preferable.
Further, the angle formed by the wall surface of the inner wall portion of the opening of the visual field limiting unit and the first main surface of the sensor unit is 90 degrees. Alternatively, the angle formed by the wall surface of the inner wall portion and the first main surface of the sensor unit may be greater than 90 degrees, and the inner wall portion may have a reverse taper structure.

(Production method of field-of-view restriction unit)
In the manufacturing method of the visual field limiting unit according to the present embodiment, the second member disposing step of disposing the second member having the opening region on the support member, and the optical opening portion being formed in a part on the opening region. And a first member forming step of forming the first member on the second member.
According to the above manufacturing method, the above-described visual field limiting unit of the present embodiment can be manufactured easily and with high accuracy. That is, by first disposing the second member having the opening region on the support member, this opening can be used as a reference region when forming an optical opening to be disposed in the next step. It is possible to manufacture simply and with high accuracy.

In the method of manufacturing the field-of-view restriction unit according to this embodiment, when the optical adjustment unit is to be arranged in the opening, the optical adjustment unit is arranged in the opening region of the second member on the support member before the first member forming step. The method further includes a step. Thereby, it is possible to manufacture a field-of-view restriction unit including an optical adjustment unit easily and with high accuracy.
From the viewpoint of increasing the manufacturing efficiency, in the method for manufacturing the visual field limiting unit of the present embodiment, the second member arranged in the second member arranging step includes a plurality of opening regions, and the first member is formed after the first member forming step. It is preferable to further include a cutting step of dividing the plurality of opening regions into individual pieces (that is, physically dividing the plurality of opening regions, respectively).

(Sensor unit)
In the present embodiment, the sensor unit has a quantum infrared sensor unit on the first main surface side. Although it does not restrict | limit in particular, The form which sealed resin other than one main surface (namely, light-receiving surface) of a quantum type infrared sensor part may be sufficient. The sensor unit includes a base and a quantum infrared sensor unit provided on the base. The quantum sensor unit may be configured with one light receiving unit or may be configured with a plurality of light receiving units. In the case of a plurality of light receiving units, for example, it is preferable that the light receiving units are arranged symmetrically with respect to the center of the opening in a plan view, for example, so as to have the same viewing angle and the same viewing area. In addition to the quantum infrared sensor unit, the sensor unit may further include the signal correction unit described above in the sensor unit. Further, the sensor unit may include a wiring or a terminal for outputting a signal output from the quantum infrared sensor unit directly or indirectly to the outside. A lead frame is preferably used as such wiring or terminal from the viewpoint of ease of manufacture.

(Quantum infrared sensor unit)
In this embodiment, a quantum type infrared sensor part outputs the signal according to the incident infrared rays. As a method of extracting the signal, a current output or a voltage output may be used.
A specific configuration of the quantum infrared sensor unit includes a semiconductor multilayer unit having a PN or PIN junction. Specific examples of the semiconductor stacked portion having a PN or PIN junction include those using a compound semiconductor layer containing indium and antimony. From the viewpoint of being able to operate at room temperature without a cooling mechanism, it is preferable to provide a barrier layer having a large band gap in a part of the semiconductor stacked portion. An example of a barrier layer having a large band gap is AlInSb.
In addition, as described above, the quantum infrared sensor unit of the present embodiment may include a plurality of light receiving units. The plurality of light receiving units can output signals corresponding to the incident infrared rays independently of each other.

(Signal correction unit)
In the present embodiment, the signal correction unit receives an output signal from the quantum infrared sensor unit, corrects the output signal, and outputs the corrected signal. The correction method is not particularly limited, but from the viewpoint of correcting with high accuracy, gain correction that multiplies the output signal by a predetermined value, offset correction that adds or subtracts the predetermined value, and the like are preferable. It is more preferable to apply both.
The predetermined values used for gain correction and offset correction may be fixed values or variable values. The method for obtaining the predetermined values used for gain correction and offset correction is not particularly limited. For example, a method for determining according to a signal output when a measurement object having a known temperature is arranged in the external visual field of the quantum infrared sensor unit. Is mentioned.

Hereinafter, the infrared detection device, field-of-view restriction unit, and manufacturing method thereof according to this embodiment will be described in more detail with reference to the drawings. Note that, in each drawing described below, parts having the same configuration are denoted by the same reference numerals, and repeated description is omitted.
<First Embodiment>
FIG. 1 is a schematic external view showing a configuration example of an infrared detecting device 100 according to the first embodiment of the present invention. 1A is a schematic plan view from above, and FIG. 1B is a schematic cross-sectional view of FIG. 1A taken along line X1-X′1.
As shown in FIGS. 1A and 1B, the infrared detection device 100 includes a sensor unit 10 and a visual field restriction unit 20.

The sensor unit 10 includes a resin sealing portion 12 serving as a base, and a quantum infrared sensor portion 11 embedded on one surface side (that is, the first main surface side) of the resin sealing portion 12. The resin sealing portion 12 is, for example, a thermosetting epoxy resin package. The light receiving surface of the quantum infrared sensor unit 11 is exposed from the resin sealing unit 12 and is, for example, substantially flush with the first main surface.
The field-of-view restriction unit 20 has an opening 23 that restricts the field of view of the quantum infrared sensor unit 11, and the sensor is configured such that the quantum infrared sensor unit 11 is optically connected to the outside through the opening 23. It is provided on the first main surface of the unit 10. The visual field limiting unit 20 includes a first member 21 having an emissivity at 25 ° C. of 0.7 or more and a second member 22 having an emissivity at 25 ° C. of 0.3 or less.

As shown in FIGS. 1A and 1B, the opening 23 is formed in the first member 21. As a result, the inner wall 201 of the opening 23 serves as the first member 21. The second member 22 is exposed on the outer surface 202 parallel to the first main surface of the sensor unit 10 among the outer surfaces of the visual field limiting unit 20. The second member 22 does not cover the opening 23. That is, as shown in FIG. 1A, the second member 22 is exposed in at least a part of a region surrounding the opening 23 in a plan view on the outer surface of the visual field limiting unit 20.
FIG. 2 is a schematic cross-sectional view for explaining the function and effect of the infrared detecting device 100 according to the first embodiment. In FIG. 2, the boundary between the external visual field and the internal visual field of the quantum infrared sensor unit 11 is indicated by a dotted line, and the external visual field is indicated by an arc line of a double arrow. Moreover, the infrared rays emitted from the measurement object are indicated by a one-dot broken line with an arrow.

  In the infrared detecting device 100 of the first embodiment, the inner wall portion of the opening 23 of the visual field limiting unit 20 is the first member 21 having an emissivity of 0.7 or more at 25 ° C. Further, the second member 22 having an emissivity of 0.3 or less at 25 ° C. is exposed on the outer surface of the field limiting unit 20 parallel to the first main surface of the sensor unit 10. Thereby, out of the infrared rays emitted from the measurement object in the external field of view, the infrared rays that are not incident on the quantum infrared sensor unit 11 and are incident on the field limiting unit 20 are reflected on the second member 22 (for example, the outer surface). , The metal part) is reflected without being absorbed, so that the temperature change of the visual field limiting unit 20 is suppressed. As a result, since the temperature difference between the visual field limiting unit 20 in the internal visual field of the quantum infrared sensor unit 11 and the quantum infrared sensor unit 11 itself is reduced, highly accurate measurement is possible.

<Second Embodiment>
FIG. 3 is a schematic external view showing a configuration example of an infrared detection apparatus 200 according to the second embodiment of the present invention.
As shown in FIG. 3, in the infrared detection device 200 according to the second embodiment, the quantum infrared sensor unit 11 includes a plurality of light receiving units 111 and 112. When deriving correction conditions (such as gain correction and / or offset correction) so that the output signals S111 and S112 from the light receiving units 111 and 112 have the same value at the temperature of a plurality of different measurement objects, both light receiving units If the temperature of the inner wall portion of the visual field limiting unit 20 that is the internal visual field of 111 and 112 and the temperature of the light receiving portions 111 and 112 themselves are different, correction is performed so that the temperature is the same at the temperature of a plurality of different measurement objects. Even if the condition is derived, a signal corresponding to the temperature difference from the inner wall portion is also superimposed, so that deviation from the true value (output signal indicating the temperature of the measurement object) occurs in the actual measurement environment.

  However, in the infrared detection device 200 of the second embodiment, the inner wall portion of the opening 23 of the visual field restriction unit 20 is the first member 21, and the second member 22 of the visual field restriction unit 20 is the first member of the sensor unit 10. It is exposed on the outer surface parallel to the main surface. As a result, the temperature difference between the inner wall portion of the visual field limiting unit 20 which is the internal visual field of both the light receiving units 111 and 112 and the temperature difference between the light receiving units 111 and 112 itself is reduced and becomes the same. Therefore, it is possible to derive a more accurate correction condition.

(Production method of field-of-view restriction unit)
FIG. 4 is a schematic diagram for explaining the manufacturing method of the visual field limiting unit 20 according to the embodiment of the present invention in the order of steps. As shown in FIG. 4A, first, the second member 22 having an opening region is disposed on the support member 105. Next, as shown in FIG. 4B, the mold 110 is disposed on the support member 105. Then, as shown in FIG. 4C, the first member 21 is formed on the support member 105 so as to cover the second member 22 and to form an optical opening partly on the opening region. . The first member 21 is formed by injection molding, for example. Next, as shown in FIG.4 (d), the formed 1st member 21 is cut | disconnected and a some opening area | region is divided | segmented separately. That is, the plurality of openings are physically divided. Thereby, the some visual field restriction | limiting unit 20 can be manufactured. As shown in FIG. 4E, the field-of-view restriction unit 20 obtained in this way is placed on the sensor unit 10 having the quantum infrared sensor unit 11 via the opening 23. Arrange it so that it is optically connected to the outside. Thereby, the infrared detection device 100 of the first embodiment or the infrared detection device 200 of the second embodiment can be obtained.

(About emissivity measurement method)
As an example of the emissivity measurement method, there is a method in which a sample to be measured and a black body as a reference for emissivity are prepared, and an emissivity of the sample is measured by combining an FTIR apparatus which is an infrared spectrophotometer. . The sample and black body are brought to a certain temperature, for example, 25 ° C., and the amount of infrared rays by thermal radiation of the sample and black body is measured using an FTIR apparatus. Then, the emissivity is calculated from the ratio of the amount of infrared radiation due to thermal radiation of the sample to the amount of infrared radiation due to thermal radiation of the black body. When detecting the amount of infrared rays with the FTIR apparatus, the area for measuring the thermal radiation of the sample and the black body needs to be equalized using an aperture or the like.

<Verification experiment>
Next, the verification experiment conducted by the inventor and the result thereof will be described.
(First infrared sensor unit for verification)
FIG. 5 is a plan view showing a configuration example of the first verification infrared sensor unit 600. FIG. 6 is a cross-sectional view of FIG. 5 taken along X5-X′5. FIG. 7 is a cross-sectional view of FIG. 5 taken along Y5-Y′5.
The inventor has a first verification infrared sensor unit (hereinafter referred to as a first verification unit) 600 shown in FIGS. 5 to 7 and a second verification infrared sensor unit (hereinafter referred to as a second verification unit). Unit) 700 and a verification experiment of the present invention was conducted.

  The infrared unit 500 common to the first verification unit 600 and the second verification unit 700 includes a sensor unit 30 and a field-of-view restriction unit 40 as shown in FIGS. The sensor unit 30 is symmetrical with respect to the center of the opening so as to be embedded in the thermosetting epoxy resin package 31 serving as a base and to be embedded in the thermosetting epoxy resin package 31 to have the same viewing angle and the same viewing area. The infrared detection unit 32 includes four light receiving units 311, 312, 313, and 314 and a terminal unit 33 for inputting and outputting signals to and from the sensor unit 30. The field-of-view restriction unit 40 includes a square opening with a side of 500 μm arranged above the infrared detection unit 32, and an optical filter 42 whose main material is made of Si. The inner wall 41 of the visual field limiting unit 40 is made of a mold resin having an emissivity of 0.95. The field-of-view restriction unit 40 and the resin package 31 are attached with an adhesive 51.

Each of the four light receiving parts 311 to 314 of the infrared detection part 32 is configured as a photodiode having a PIN structure including a light absorption layer and a barrier layer on a compound semiconductor substrate. A photodiode having a PIN structure includes a n-type indium antimony (InSb) layer, a p-type InSb layer, an n-type InSb layer, and a p-type InSb layer on a gallium arsenide (GaAs) substrate as a compound semiconductor substrate. An i-type InSb layer as a light absorption layer, and a p-type aluminum indium antimony (AlInSb) layer as a barrier layer for preventing leakage of carriers generated between the p-type InSb layer and the i-type InSb layer, It is constructed by stacking.
FIG. 8 is a plan view showing a first verification unit 600 in which an aluminum tape 61 is installed on the infrared unit 500. FIG. 9 is a cross-sectional view of FIG. 8 taken along X8-X′8. FIG. 10 is a cross-sectional view of FIG. 8 taken along Y8-Y′8.

As shown in FIG. 8 to FIG. 10, in this verification experiment, the infrared unit 500 is subjected to 25 ° C. on the entire outer surface of the visual field limiting unit 40, which is parallel to the first main surface of the infrared unit 500. An aluminum tape 61 having an emissivity of 0.2 was installed. Since the aluminum tape 61 is also disposed on the optical filter 42, the infrared rays incident from the external visual field disappear, and the infrared detection unit 32 detects the output from the inner wall portion 41 and the amount of infrared rays only from the aluminum tape. Since the output from the aluminum tape has a low emissivity and a small area with respect to the inner wall portion 41, an extremely small amount of infrared rays is emitted relative to the amount of infrared rays radiated from the inner wall portion 41. Therefore, the sensor output at this time is It can be said that this is the sensor output of the internal visual field emitted by the inner wall portion 41.
Then, as shown in FIG. 11, a planar black body in which an infrared sensor unit (that is, the first verification unit 600) in which the aluminum tape 61 is attached to the infrared unit 500 is set to 50 ° C. in a room temperature environment of 23 ° C. It arrange | positions facing the furnace 800 (heat source), and acquired the output (S311-S314) from the four light-receiving parts 311-314.

(Second verification infrared sensor unit)
FIG. 12 is a plan view showing a state in which the aluminum tape 71 having an emissivity of 0.2 at 25 ° C. is installed only on the optical filter 42 in the infrared unit 500. FIG. 13 is a cross-sectional view of FIG. 12 taken along X12-X′12. It is sectional drawing which cut | disconnected FIG. 14 by Y12-Y'21.
As shown in FIG. 12 to FIG. 14, infrared rays are irradiated in the same manner as the first verification unit 600 except that an aluminum tape 71 having an emissivity of 0.2 at 25 degrees is installed only on the optical filter 42. A sensor unit (ie, the second verification unit 700) was constructed.
Then, as shown in FIG. 15, the second verification unit 700 is placed opposite to the flat black body furnace 800 (heat source) set to 50 ° C. in a room temperature environment of 23 ° C. (with a separation distance from the heat source). The outputs (S311 to S314) from the four light receiving units 311 to 314 were acquired.
As shown in FIGS. 11 and 15, the first and second verification units 600 and 700 on which the aluminum tapes 61 and 71 are installed are arranged opposite to the flat black body furnace (heat source) 800 set to 50 ° C. Outputs (S311 to S314) were obtained from the four light receiving units 311 to 314. Table 1 shows outputs (S311 to S314) acquired from the first and second verification units 600 and 700, respectively.

As shown in Table 1, when the aluminum tape 61 is installed on the entire outer surface of the field-of-view restriction unit 40 that is parallel to the first main surface of the sensor unit 30 (that is, the first verification unit 600). Compared with the case where the aluminum tape 71 is installed only on the optical filter 42 (that is, the second verification unit 700), the output from the internal visual field is reduced.
Further, by performing gain correction on the signals output from the light receiving units 311 to 314, it is possible to obtain a correction condition for canceling the characteristic variations of the light receiving units 311 to 314 due to manufacturing variations and the like with high accuracy. Show. A gain correction value that adjusts so that the signals output from each light receiving unit have the same value when a measurement object having a known uniform temperature is installed in each light receiving unit 311 to 314 in the entire external visual field of each light receiving unit. First, sensor output by infrared rays from a black body furnace at 50 ° C. is acquired as infrared energy inputted from the outside.

  Here, the infrared unit 500 (with the aluminum tapes 61 and 71 removed) constructing the first and second verification units 600 and 700 was exposed in front of the flat blackbody furnace 800. Thereby, the infrared unit 500 outputs both infrared energy from the internal visual field and infrared energy from the external visual field. The difference between this sensor output and Table 1 which is the sensor output of the second verification unit 700 in which only the optical filter 42 is covered with the aluminum tape 71 is the sensor output by infrared rays from the external visual field of the infrared unit 500, The values are shown in Table 2.

表２に示す４つの出力を全てＳ３１１の出力値に揃えるようなゲイン補正値を求めると、表３となる。

Table 3 shows the gain correction values obtained by aligning all four outputs shown in Table 2 with the output values of S311.

Table 3 shows gain correction values for canceling the variation in characteristics of each light receiving unit due to the manufacturing variation adjusted in the external visual field.
When the gain correction value is obtained and adjusted for each manufactured individual, the output by the infrared energy of the internal visual field is estimated as calculated in Tables 2 and 3, and the infrared energy input from the external visual field and the internal visual field is used. The difference between the output and the output by the infrared energy of the internal visual field is obtained. This difference becomes the output by the infrared energy of the external visual field. Then, a gain correction value is calculated so that the output of each light receiving unit is aligned with one preset output for the output of infrared energy of the external visual field.

As described above, the method for estimating the sensor output of only the infrared energy of the external visual field takes a lot of time for adjustment and reduces the manufacturing efficiency. Therefore, in order to increase the manufacturing efficiency and to make a quick adjustment, the gain correction value is accurately determined only by exposing the sensor to a 50-degree planar blackbody furnace. Therefore, the present embodiment has an effect of reducing the influence of the infrared energy of the internal visual field by the second member 22, and thus is a very effective means for obtaining an accurate gain correction value.
Table 4 shows the outputs obtained by exposing the 50 degree planar blackbody furnace to the first and second verification units 600 and 700, respectively.

表４の値からＳ３１１を１とするようにゲイン補正値を求めると、表５となる。

When the gain correction value is obtained from the values in Table 4 so that S311 is 1, Table 5 is obtained.

  Table 5 shows gain correction values including the effects of both the external visual field and the internal visual field. An error corresponding to the influence of the internal visual field is generated from the gain correction value adjusted only by the external visual field. The smaller the error, the more accurately the gain correction value can be determined. The difference between the gain correction value including the effects of both the external visual field and the internal visual field in Table 5 and the gain correction value adjusted only in the external visual field in Table 3 is an error. Table 6 shows the error [%].

   Comparing the errors of the gain correction values of the first verification unit 600 and the second verification unit 700, the entire outer surface parallel to the first main surface of the infrared unit 500 among the outer surfaces of the field-of-view restriction unit 40. It can be seen that the first verification unit 600 with the aluminum tape 61 installed has a smaller deviation in the gain correction value, and the accuracy is improved by installing a low emissivity member on the outer surface parallel to the first main surface. It can be seen that the gain correction value is well obtained.

  The present invention is suitable as an infrared sensor unit used for human body detection, a temperature sensor, and the like.

DESCRIPTION OF SYMBOLS 10 Sensor unit 11 Quantum type infrared sensor part 20 View restriction unit 21 1st member 22 2nd member 23 Opening part 30 Sensor unit 31 Epoxy resin package 31 Resin package 32 Infrared detection part 40 View restriction unit 41 Inner wall part 42 Optical filter 51 Adhesion Agents 61, 71 Aluminum tape 100, 200 Infrared detector 105 Support member 110 Forms 111, 112, 311 to 314 Light receiving portion 201 Inner wall portion 202 Outer surface 500 Infrared unit 600 First infrared sensor unit for verification (first verification) Unit)
700 Infrared sensor unit for second verification (second verification unit)
800 Plane blackbody furnace

Claims (15)

A sensor unit having a quantum infrared sensor on the first main surface side;
On the first main surface of the sensor unit, an opening for limiting a field of view of the quantum infrared sensor unit is provided, and the quantum infrared sensor unit is optically connected to the outside through the opening. A visual field limiting unit provided,
The visual field limiting unit includes a first member having an emissivity at 25 ° C. of 0.7 or more, and a second member having an emissivity at 25 ° C. of 0.3 or less,
The inner wall of the opening of the visual field limiting unit is the first member,
The infrared detection apparatus in which the second member is exposed on a surface parallel to the first main surface of the sensor unit, of the outer surface of the visual field limiting unit.   The infrared detection device according to claim 1, wherein the second member is made of metal.   The infrared detection device according to claim 2, wherein at least a part of a surface exposed to the outer surface of the metal is plated with Sn.   The infrared detection device according to claim 2, wherein the metal contains Cu.   The infrared detection apparatus according to claim 1, wherein a thickness of the second member in a direction perpendicular to the first main surface of the sensor unit is 500 μm or less.   The infrared detection apparatus according to claim 1, wherein the first member is made of a resin.   The infrared detection apparatus according to claim 1, wherein the quantum infrared sensor unit includes a plurality of light receiving units, and the plurality of light receiving units each independently output a signal.   The infrared detection device according to claim 1, further comprising a signal correction unit that receives an output signal from the quantum infrared sensor unit, corrects the output signal, and outputs the corrected signal.   The infrared detection device according to claim 1, further comprising an optical adjustment unit provided in the opening.   The infrared detection device according to any one of claims 1 to 9, wherein an angle formed by a wall surface of the inner wall portion and the first main surface of the sensor unit is greater than 90 degrees. An opening for limiting the field of view of the quantum infrared sensor part of the sensor unit having the quantum infrared sensor part on the first main surface side;
A first member having an emissivity at 25 ° C. of 0.7 or more;
A second member having an emissivity at 25 ° C. of 0.3 or less,
The inner wall portion of the opening is made of the first member,
When the visual field limiting unit is mounted on the first main surface of the sensor unit, the second member is disposed on a surface parallel to the first main surface of the sensor unit among the outer surfaces of the visual field limiting unit. Exposed view restriction unit. A second member disposing step of disposing a second member having an opening region on the support member;
A first member forming step of forming a first member on the support member so as to cover the second member and to form an optical opening in a part of the opening region;
A material having an emissivity of 0.7 or more at 25 ° C. is used for the first member,
A method for manufacturing a visual field limiting unit, wherein the second member is made of a material having an emissivity of 0.3 or less at 25 ° C.   The manufacturing method of the visual field restriction unit according to claim 12, further comprising a step of arranging an optical adjustment unit in the opening region of the second member arranged on the support member before the first member forming step. The second member arranged in the second member arrangement step includes a plurality of opening regions,
The manufacturing method of the visual field restriction unit according to claim 12 or 13, further comprising a cutting step of cutting the first member and dividing the plurality of opening regions individually after the first member forming step. A sensor unit having a quantum infrared sensor on the first main surface side;
On the first main surface of the sensor unit, an opening for limiting a field of view of the quantum infrared sensor unit is provided, and the quantum infrared sensor unit is optically connected to the outside through the opening. A visual field limiting unit provided,
The visual field limiting unit includes a first member having an emissivity at 25 ° C. of 0.7 or more, and a second member having an emissivity at 25 ° C. of 0.3 or less,
The inner wall of the opening of the visual field limiting unit is the first member,
The infrared detection apparatus in which the second member is exposed in at least a part of a region surrounding the opening portion in a plan view on the outer surface of the visual field limiting unit.

Images