WO2012029974A1

WO2012029974A1 - Infrared ray detection sensor and electronic apparatus

Info

Publication number: WO2012029974A1
Application number: PCT/JP2011/070158
Authority: WO
Inventors: 純一郎又賀; 岩波　瑞樹; 尚武高橋; 佐々木　康弘
Original assignee: 日本電気株式会社
Priority date: 2010-09-03
Filing date: 2011-09-05
Publication date: 2012-03-08

Abstract

This infrared ray detection sensor is provided with a substrate (11) and a plurality of infrared ray detection elements (12) that are mounted and disposed on the substrate (11). The plurality of infrared ray detection elements (12) include: a plurality of infrared ray detection elements (12a) that are positioned at a lower layer portion that is in the proximity of the substrate (11); and a plurality of infrared ray detection elements (12b) that are positioned at an upper layer portion that is spaced from the substrate (11). When viewing from a direction perpendicular to the surface of the substrate (11), the infrared ray detection elements (12a) positioned at the lower layer portion and the infrared ray detection elements (12b) positioned at the upper layer portion are disposed in a manner so as to overlap each other in the vertical direction.

Description

Infrared detection sensor and electronic device

The present invention relates to an infrared detection sensor and an electronic device.

Conventional infrared sensors include pyroelectric infrared sensors that use the pyroelectric effect, resistance change types that use the temperature change rate of the resistance of materials, and sensors that use changes in the electrical characteristics of semiconductor pn junctions. Yes. In particular, pyroelectric and variable resistance sensors that can operate at room temperature are used for fire detection and human body detection, and by arranging infrared detector elements in an array, infrared spatial distribution can be easily imaged with high resolution. It can be used to secure safety in the dark and search for structural materials.

On the other hand, with recent advances in information and communication technology and expansion of network infrastructure, there are new sensor usage movements such as energy saving in building air conditioning and grasping consumer behavior, and at the same time it is compact to realize a system that uses many sensors. Therefore, a highly sensitive sensor device with low manufacturing cost is desired.

Patent Document 1 describes a thermal infrared detection system for crime prevention and disaster prevention, an industrial thermal management system, and an infrared detector used for temperature distribution measurement. In this infrared detector, a plurality of infrared detection elements are arranged in a one-dimensional manner so that the infrared receiving surfaces of adjacent infrared detecting elements have a step, and the receiving surfaces contact or overlap each other when viewed from the viewing direction. Or they are arranged in two dimensions. Thereby, there is no insensitive area | region in a multi-element type infrared detector between infrared detecting elements, and mutual isolation | separation is possible.

Patent Document 2 describes an infrared sensor array with improved infrared detection sensitivity. The infrared sensor array is substantially orthogonal to an infrared sensor that is supported by legs on a substrate and includes an infrared detector having a temperature detection film and an infrared absorber supported by the support on the infrared detector. It is an infrared sensor array juxtaposed in two axial directions. The infrared sensor is disposed adjacent to each other, and includes a first infrared sensor having a plate-like infrared absorbing portion whose distance from the substrate is a, a plate-like portion, and a plate-like portion provided around the plate-like portion. And a second infrared sensor having an infrared absorbing portion having a flange portion whose distance is larger than a. And in this infrared sensor array, the infrared absorption part of a 1st infrared sensor and a 2nd infrared sensor is arrange | positioned away in the perpendicular direction of a board | substrate.

In Patent Document 3, a plurality of pyroelectric infrared detectors arranged one-dimensionally are used to detect the presence, position, and behavior of a human body in a living room at low cost and in a compact size. An infrared sensor system to perform is described. This infrared sensor system includes a signal converting means for converting a signal output from a pyroelectric infrared detector into a digital signal, a pulse counting means for counting pulses of the digital signal output from the signal converting means, and a pulse counting means. Are provided with area-specific information storage means for storing the pulse information counted in step (1), and determination means for determining data stored in the area-specific information storage means. Then, the determination unit compares the pulse information stored in the area-specific information storage unit with a preset threshold value.

Patent Document 4 describes a simple pyroelectric infrared sensor that detects a central region and its peripheral region. In this pyroelectric infrared sensor, a single element for forming a first dual element and a second dual element is sequentially arranged in a horizontal direction on a substrate made of a pyroelectric material. In this single element, infrared rays generated in different substantially continuous regions are condensed and irradiated by the Fresnel lens of the lens dome to realize a wide viewing angle. Thereby, human detection is performed in a region (center region) corresponding to the first dual element and a region (peripheral region) corresponding to the second dual element.

JP 59-222731 A JP 2004-294296 A JP 2007-187599 A JP 2007-292461 A

In Patent Document 3 and Patent Document 4, since a plurality of infrared sensors are arranged in parallel or in a grid on the same plane, there is a limit to downsizing. Moreover, in patent document 1 and patent document 2, a plurality of infrared sensors are arranged apart from each other in the vertical direction (Z-axis direction) for the purpose of eliminating a dead area between the infrared sensors. However, this has a problem in that it is difficult to obtain sufficient sensitivity.

The sensitivity of the pyroelectric material is proportional to the pyroelectric current generated by the temperature change caused by the heat generated by the received infrared light and the light receiving area of the infrared detecting element. Therefore, if the sensor element is reduced in size and the mounting area of the sensor element is reduced, the sensitivity of each infrared detecting element is lowered and the sensitivity is reduced as a whole.

The present invention has been made in view of the above circumstances, and provides an infrared detection sensor and an electronic device that can be miniaturized and can perform highly accurate detection of infrared rays distributed in a wider spatial region. The purpose is to do.

An infrared detection sensor according to a first aspect of the present invention provides:
In an infrared detection sensor comprising a substrate and a plurality of infrared detection elements mounted and arranged on the substrate,
The plurality of infrared detection elements are:
A plurality of infrared detection elements located in a lower layer portion adjacent to the substrate;
A plurality of infrared detection elements located in an upper layer portion separated from the substrate,
When viewed from a direction perpendicular to the surface of the substrate, each infrared detection element located in the lower layer portion and each infrared detection element located in the upper layer portion are arranged so as to overlap each other in the vertical direction. ing,
An infrared detection sensor characterized by that.

An electronic device according to a second aspect of the present invention is:
An infrared detection sensor according to the first aspect is provided.

According to the present invention, it is possible to reduce the size and to detect infrared rays distributed in a wider spatial region with high accuracy.

It is a composition perspective view showing an example of a pyroelectric infrared detection sensor concerning an embodiment of the present invention. 1B is a sectional view taken along line MM in FIG. 1A. FIG. It is a top view which shows an example of a pyroelectric infrared detection sensor. It is a schematic sectional drawing which shows an example of a structure of a pyroelectric infrared detection sensor. It is a top view which shows an example of an infrared sensor element. It is the NN sectional view taken on the line of FIG. 2B. It is a figure which shows an example of the manufacturing method of a pyroelectric infrared detection sensor. It is a figure which shows an example of the manufacturing method of a pyroelectric infrared detection sensor. It is a figure which shows an example of the manufacturing method of a pyroelectric infrared detection sensor. It is a figure which shows another example of the manufacturing method of a pyroelectric infrared detection sensor. It is a figure which shows another example of the manufacturing method of a pyroelectric infrared detection sensor. It is a figure which shows another example of the manufacturing method of a pyroelectric infrared detection sensor. It is a figure which shows another example of the manufacturing method of a pyroelectric infrared detection sensor. It is a schematic perspective view which shows an example of the structure of the pyroelectric infrared detection sensor which concerns on a related technique. It is a schematic perspective view which shows another example of a structure of the pyroelectric infrared detection sensor which concerns on a related technique. It is a figure which shows an example which processed the electrical signal detected with the pyroelectric infrared detection sensor into the mosaic image. It is a figure which shows another example which processed the electrical signal detected with the pyroelectric infrared detection sensor into the mosaic image. It is the voltage sensitivity graph of the detection target detected with the pyroelectric infrared detection sensor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1A is a structural perspective view showing an example of a pyroelectric infrared detection sensor according to an embodiment of the present invention. 1B is a cross-sectional view taken along line MM in FIG. 1A. FIG. 1C is a plan view illustrating an example of a pyroelectric infrared detection sensor. FIG. 2A is a schematic cross-sectional view showing an example of the configuration of a pyroelectric infrared detection sensor. FIG. 2B is a plan view showing an example of an infrared sensor element. 2C is a sectional view taken along line NN in FIG. 2B.

As shown in FIGS. 1A, 1B, and 2A, a pyroelectric infrared detection sensor 100 according to an embodiment of the present invention (hereinafter simply referred to as infrared detection sensor 100) includes a plurality of infrared sensor elements that receive infrared rays. 12 (hereinafter simply referred to as sensor elements 12), and the plurality of sensor elements 12 are arranged in an array and in a grid (lattice) on the substrate 11 so as to be staggered in the vertical direction. Mounting is arranged. The plurality of sensor elements 12 includes 15 (a plurality of) sensor elements 12a located in a lower layer portion close to the substrate 11 and eight (a plurality of) sensor elements 12b located in an upper layer portion separated from the substrate 11. Become. Here, the thickness of the substrate 11 is not particularly limited. The sensor element 12 has a thickness of 1 μm or more and 100 μm or less.

As shown in FIGS. 1A, 1B, and 2A, when viewed from a direction perpendicular to the surface of the substrate 11, each sensor element 12a located in the lower layer portion and each sensor element 12b located in the upper layer portion Are arranged so as to overlap each other in the vertical direction. Specifically, one of the sensor elements 12 (lower layer part (first stage) sensor element 12a) is part of the other sensor element (upper layer part (second stage) sensor element 12b). It is mounted on the substrate 11 so as to overlap each other in the vertical direction. Each sensor element 12b is arranged at the intersection of a cross-shaped gap formed between the four sensor elements 12a. In the present embodiment, the sensor element 12a and the sensor element 12b in which a part of each other overlaps in the vertical direction as described above are referred to as adjacent sensor elements 12. The adjacent sensor elements 12 have different heights (arrangement positions) from the substrate 11 in order to avoid contact between the sensor elements 12, that is, the

sensor elements

12a and 12b. Further, the adjacent sensor elements 12 do not interfere with the arrangement so as not to contact each other when viewed from a direction perpendicular to the surface of the substrate 11 in order to eliminate the insensitive area of the infrared detection sensor 100. It is desirable to arrange them to be as dense as possible.

As shown in FIG. 1C, a sensor array portion composed of a plurality of sensor elements 12 arranged in an array and a peripheral circuit portion 16 surrounding the sensor array portion are formed on the substrate 11. And the infrared sensor element 12 and the peripheral circuit part 16 are electrically connected by the below-mentioned wiring and bonding wire (not shown). The peripheral circuit unit 16 is connected to an image processing device (not shown). In this image processing apparatus, information for a mosaic image obtained by processing an electrical signal transmitted from the infrared detection sensor 100 (the plurality of sensor elements 12) is generated based on a detection target such as a human body, and the mosaic is displayed in a display apparatus (not shown). (See FIGS. 6A and 6B).

The sensor element 12 is a conventionally well-known element, and as shown in FIGS. 2B and 2C, the pyroelectric ceramic film 10 having a rectangular shape as a whole and having two main surfaces as a pyroelectric body, The upper and lower electrode layers 18 and 19 are formed on both main surfaces of the pyroelectric ceramic film 10. In the sensor element 12, the upper main surface constitutes a detection surface 17d, and a rectangular light receiving surface 17c is formed on the detection surface 17d. The upper electrode layer 18 is disposed in the light receiving surface 17c. The electrode layer 18 includes four (plural) rectangular electrodes 17a arranged in parallel to each other, and the electrode layer 19 includes four (plural) plural rectangular electrodes arranged in parallel to each other. 17b is included. Here, the electrode patterns formed on the upper and lower electrode layers may be arbitrarily set as long as they can be electrically connected to other electric elements.

When the pyroelectric ceramic film 10 is irradiated with infrared rays, a pyroelectric effect proportional to the area of the light receiving surface 17c of the sensor element 12 is generated according to the irradiation amount and wavelength of the infrared rays. And the pyroelectric charge resulting from this pyroelectric effect is induced in the pyroelectric ceramic film 10, and this induced electric charge becomes a potential difference in the upper and lower electrode layers 18 and 19. Then, by measuring this potential difference as an electrical signal using an appropriate electrical circuit (here, the peripheral circuit unit 16), the irradiated infrared ray can be detected. Specifically, since the amount of infrared light received by each sensor element 12 varies according to the movement of the human body that is the detection target, the infrared detection sensor 100 increases the movement of the human body by analyzing the time variation data. Detection is possible with detection sensitivity.

The material of the pyroelectric material used in the present embodiment is not particularly limited, and ceramic pyroelectric materials such as lead zirconate titanate ceramics (PZT) and lithium tantalate ceramics, and organic pyroelectrics such as polyvinylidene fluoride. Body material can be used. Among these, lead zirconate titanate ceramics (PZT) having a high pyroelectric coefficient and capable of maximizing the pyroelectric effect by polarization treatment can be cited as a desirable example.

In this embodiment, referring to FIG. 2C, the electrical connection between the substrate 11 and the electrode layer 19 (pyroelectric part) under the sensor element 12 is formed on the substrate 11 by plating. It is possible to use a metal wiring that has been made. Further, for the connection between the wiring and the upper electrode layer 18, a wire bonding method can be used in addition to the plating method.

In the infrared detection sensor 100 according to the present embodiment, for example, the sensor element 12 is formed on the substrate 11 by a film forming process or pasting, and is integrally joined, and further, electrodes and wiring for electrical connection are formed. Then, it is manufactured by further sealing and packaging. As shown in FIG. 2A, the sealed package is provided with an optical filter 15 that transmits only infrared light having a wavelength suitable for a detection target. Further, as shown in FIG. 2A, in order to efficiently collect infrared light incident from a wide range and detect it with the array-shaped sensor element 12, an optical diffraction element 14 such as a Fresnel lens is provided near the optical filter 15. Can also be provided.

3A to 3C show an example of a method for manufacturing the infrared detection sensor according to the present embodiment.

In order to form a plurality of sensor elements 12 so as to be staggered in the vertical direction and in two layers (multilayers) as in the infrared detection sensor 100, FIG. 3B and FIG. It is necessary to continue the process shown in 3C.

First, as shown in FIG. 3A, a plurality of sensor elements 12 a (sensor elements 12) are formed on the prepared substrate 11. Here, the plurality of sensor elements 12a are arranged in a grid so that the adjacent sensor elements 12a are equidistant.

Here, the material of the substrate 11 is not particularly limited, and a metal material (for example, aluminum alloy, copper alloy, iron, iron-based alloy, titanium, or titanium alloy) or a resin material (epoxy, acrylic, polyimide). , Polycarbonate, etc.) and ceramic materials (alumina, silica, magnesia, or their compounds, composites, etc.) can be selected and used according to the desired shape and use environment.

The sensor element 12a can be formed on the substrate 11 by using, for example, an aerosol deposition method in which ceramic fine particles are sprayed at a high speed, a solution method such as a sol-gel method, or a gas phase method (MOCVD method or the like). These methods can be appropriately selected and used according to the material and shape of the substrate 11. In addition, a method of producing a pyroelectric ceramic plate by a method such as a tape casting method and bonding it to the substrate 11 using an adhesive can be used for manufacturing the sensor element 12a. For example, an epoxy adhesive can be used as the adhesive. The thickness of the obtained adhesive layer is not particularly limited, but is 10 μm or more and 20 μm or less, preferably 5 μm or more and 20 μm or less. If the thickness of the adhesive layer exceeds 20 μm, unnecessary electrical resistance components increase, which is not preferable because the infrared detection sensitivity may decrease. If the thickness of the adhesive layer is less than 10 μm, the adhesive strength is low. Since it may be insufficient, it is not preferable.

Next, as shown in FIG. 3B, a plurality of leg portions 13 are formed using a resin material having low thermal conductivity, and the leg portions 13 are respectively arranged in regions formed between the plurality of sensor elements 12a. To do. Here, the plurality of leg portions 13 are arranged on the leg portions 13 and arranged in a grid so that adjacent sensor elements 12b are equally spaced (see FIG. 1A). Each leg 13 is arranged at the intersection of a cross-shaped gap formed between the four sensor elements 12a (see FIGS. 1A and 1B). In addition, the height of the leg part 13 is made higher than the sensor element 12a.

Subsequently, as shown in FIG. 3C, the sensor elements 12b are bonded and fixed on the respective leg portions 13 by using, for example, an epoxy adhesive. As a result, the plurality of sensor elements 12 a are arranged in a grid on the substrate 11 via the legs 13. Here, the main surface (light receiving surface 17 c) of each sensor element 12 b is arranged to be parallel to the surface of the substrate 11. At this time, the sensor element 12b is disposed so as to avoid contact between the sensor element 12b and the adjacent sensor element 12a and contact between the sensor element 12b and the closest sensor element 12b.

Here, as shown in FIG. 3C, the sensor element 12 b was arranged so as to be parallel to the substrate 11. However, the present invention is not limited to this, and the installation of the leg portion 13 in which the installation surface of the sensor element 12b is inclined in advance with respect to the surface of the substrate 11 in a range where it does not contact the adjacent sensor element 12a and the closest sensor element 12b. The sensor element 12b may be bonded on the surface, and the main surface (light receiving surface 17c) of the sensor element 12b may be inclined with respect to the surface of the substrate 11. Further, when the sensor element 12a is arranged on the substrate 11, a plurality of inclined surfaces inclined from the horizontal plane (the surface of the substrate 11) are previously formed on the substrate 11, and the sensor element 12a is arranged on the inclined surface. Thus, the main surface (light receiving surface 17c) of the sensor element 12b can be inclined with respect to the surface of the substrate 11.

4A to 4D show another example of the method for manufacturing the infrared detection sensor 100 according to the present embodiment.

In order to form a plurality of sensor elements 12 so as to be staggered in the vertical direction and in two layers (multilayers) like the infrared detection sensor 100, after the step of FIG. 4A, FIG. 4B to FIG. It is necessary to continue the process shown in 4D.

First, as shown in FIG. 4A, a substrate 21 is prepared. As the material of the substrate 21, the same material as that of the substrate 11 described in the manufacturing method of FIGS. 3A to 3C can be used. Here, the substrate 21 is preferably thicker than the substrate 11 in order to form a plurality of recesses 21b.

Next, as shown in FIG. 4B, the substrate 21 is subjected to grid-like pattern processing to form a plurality of recesses 21b that can be accommodated in the sensor elements 12a. Here, when the sensor element 12a is accommodated in each recess 21b, the sensor element 12a arranged in the step shown in FIG. 4C contacts the sensor element 12b arranged on the recess 21b in the step shown in FIG. 4D. In order to avoid this, the depth of the recess 21b is set deeper than the height of the sensor element 12a.

Subsequently, as shown in FIG. 4C, the sensor element 12a is bonded and fixed on the portion constituting the bottom surface of each recess 21b (herein, referred to as “integrated substrate 21a”) using an epoxy adhesive. Then, the plurality of sensor elements 12a are sequentially arranged on the integrated substrate 21a. Thereby, the plurality of sensor elements 12a are arranged in a grid on the substrate 21 (integrated substrate 21a).

Subsequently, as shown in FIG. 4D, each concave portion 21b is already arranged in each concave portion 21b on a grid-like portion (herein referred to as “integrated leg portion 21c”) that constitutes a square cylindrical side wall. The plurality of sensor elements 12b are bonded and fixed using an epoxy adhesive so as not to contact the sensor element 12a. Accordingly, the plurality of sensor elements 12b are arranged in a grid on the substrate 21 via the integrated leg portion 21c. Each sensor element 12b is arranged at the intersection of a cross-shaped gap formed between the four sensor elements 12a.

It is preferable that the

adjacent sensor elements

12a and 12b be as small as possible from each other as long as the elements do not contact each other. Further, the sensor element 12a and the sensor element 12b are arranged in three or more layers (three or more steps) even if they are arranged in two upper and lower layers (two steps) regardless of the angle, shape and size with respect to the substrate 11. May be.

Hereinafter, the result of comparing the detection accuracy of the infrared detection sensor 100 according to the present embodiment and the

infrared detection sensors

101 and 102 according to the related technology will be described. 5A and 5B are schematic perspective views illustrating an example of the configuration of the

infrared detection sensors

101 and 102 according to the related technology.

Here, the measurement result by the infrared detection sensor 100 shown in FIG. 1A is taken as an example. Moreover, the measurement results by the

infrared detection sensors

101 and 102 shown in FIGS. 5A and 5B are referred to as Comparative Example 1 and Comparative Example 2, respectively.

The mounting area where the

infrared detection sensors

100, 101, and 102 corresponding to the example, comparative example 1, and comparative example 2 are mounted on the substrate 11 is the same, and infrared rays from the detection target are also detected under the same conditions. The light is incident on the

sensors

100, 101, and 102. Moreover, the same thing was used also about the electronic component etc. which are required for the sensor element 12 (sensor element 12a, sensor element 12b) to be used, and others. Further, the

infrared detection sensors

100, 101, and 102 were supplied with the same electric power during the measurement of infrared rays, and the usage environments such as temperature, humidity, and pressure were also the same.

In Examples, Comparative Examples 1 and 2, a MgO substrate having a rectangular shape with sides of 45 mm and 30 mm and a thickness of 100 μm (0.05 mm) was used as the substrate 11. The pyroelectric ceramic film 10 of the sensor element 12 is made of lead zirconate titanate ceramic, and the upper and lower electrode layers 18 and 19 (

electrodes

17a and 17b) are silver / palladium alloys (weight ratio 70%: 30%) was used. In the embodiment, a resin material having a low thermal conductivity, for example, an epoxy resin, an acrylic resin, a polyimide resin, a polycarbonate resin, or the like is used for the leg portion 13 that fixes the sensor element 12b to the substrate 11.

<Example>
In the present embodiment, as described above, the infrared detection sensors 100 shown in FIG. 1A, that is, the sensor elements 12 in the upper layer portion and the lower layer portion are alternately arranged in the vertical direction, and two layers (multilayer) in a grid shape. A pyroelectric infrared array sensor arranged in the above was used.

Here, the sensor element 12 has a square shape with a side of 5 mm, and the upper and lower main surfaces of the pyroelectric ceramic film 10 with a thickness of 15 μm (0.015 mm) formed with

electrode layers

18 and 19 with a thickness of 5 μm. did. Further, in the lower layer portion on the substrate 11, the sensor elements 12 a are separated from each other by 3 mm to form a 3 × 5 grid arrangement. Further, in the upper layer portion on the substrate 11, the sensor elements 12b are separated from each other by 3 mm to form a grid-like arrangement of 2 rows × 4 columns. Here, 23 sensor elements 12 were used in total (upper layer portion: 8 and lower layer portion: 15). Each sensor element 12b is arranged at the intersection of a cross-shaped gap formed between the four sensor elements 12a.

<Comparative Example 1>
In this comparative example 1, the infrared detection sensor 101 shown in FIG. 5A was used. Specifically, an infrared array sensor in which the sensor elements 12 (pyroelectric bodies) are mounted on the substrate 11 in a grid shape so as to have the same mounting area as the infrared detection sensor 100 of the example is used. Here, since the sensor elements 12 are not arranged in the upper layer portion, the number of pyroelectric bodies, that is, the number of sensor elements 12 is 15, which is smaller than that of the embodiment.

<Comparative Example 2>
In this comparative example 2, the infrared detection sensor 102 shown in FIG. 5B was used. Specifically, the same number of sensor elements 12c as the infrared detection sensors 100 of the embodiment (the area of the light receiving surface 17c of each sensor element 12 is smaller than that of the sensor elements 12 of the embodiment) are formed on the substrate 11 in a grid pattern. An arrayed infrared array sensor was used.

6A and 6B are diagrams showing mosaic images obtained by processing the electrical signals generated by the

infrared detection sensors

100 and 101 in the example and the comparative example 1. FIG. FIG. 6A is based on the example (infrared detection sensor 100), and FIG. 6B is based on the comparative example 1 (infrared detection sensor 101). As described above, in the

infrared detection sensors

100 and 101, different levels of electrical signals are generated in the sensor elements 12 of the plurality of sensor elements 12 (sensor array portions) depending on the detection target. Thus, it can be converted into information for a mosaic image.

As shown in FIG. 6A, by using the infrared detection sensor 100 of the above embodiment, a larger number of sensor elements 12 can be mounted in the same mounting area on the substrate 11, and the comparative example shown in FIG. 6B. As compared with the first infrared detection sensor 101, it is possible to display a higher-definition image.

FIG. 7 shows a voltage sensitivity graph of a detection target detected by the

infrared detection sensors

100 and 102 of the above-described example and comparative example 2. Graph A and graph B show the results of the infrared detection sensor 100. Here, the graph A shows the result of the sensor element 12b in the upper layer part, and the graph B shows the result of the sensor element 12a in the lower layer part. Graph C shows the result of the infrared detection sensor 102.

From FIG. 7, by using the infrared detection sensor 100 of the above embodiment, both the detection by only the sensor element 12 b in the upper layer part and the detection by only the sensor element 12 a in the lower layer part are more than the infrared detection sensor 102. The peak was high, and in the same mounting area on the substrate 11, the infrared detection area by the infrared detection sensor 100 was improved. As a result, high voltage sensitivity could be obtained.

In addition, regarding the sensor element 12a in the lower layer part, when the area of the main surface (detection surface 17d) on the same is the same, a better infrared detection result is obtained when the area of the light receiving surface 17c is smaller. This phenomenon is thought to be due to the rapid temperature change of the entire sensor element (detection surface 17d) due to heat conduction from the infrared light receiving surface 17c.

From the above results, it can be easily inferred that higher voltage sensitivity can be obtained by combining the detection results of the sensor element 12a in the upper layer part and the sensor element 12b in the lower layer part as the entire infrared detection sensor 100.

As described above, according to the infrared detection sensor 100 of the present embodiment, it is possible to reduce the size, and it is possible to detect the infrared rays distributed in a wider spatial region with high accuracy.

According to the infrared detection sensor 100 of the present embodiment, by arranging a plurality of sensor elements 12 alternately in the vertical direction, the sensor element 12b in the upper layer part receives infrared rays on the entire detection surface 17d, and In the sensor element 12a, the heat of the light receiving surface 17c that receives infrared rays induces a temperature change other than the light receiving surface 17c due to heat conduction in the sensor element 12a. As a result, the temperature change of the sensor element 12a is made efficient with respect to the same amount of incident infrared rays, and a large amount of pyroelectric charge is obtained, so that an infrared detection sensor with high density and high sensitivity is realized.

Note that the configuration of the infrared detection element described in the embodiment is an example, and can be changed without departing from the technical idea of the present invention.

For example, in the above embodiment, the infrared detection sensor 100 and each sensor element 12 are rectangular. However, the present invention is not limited to this, and the shapes of the infrared detection sensor 100 and each sensor element 12 may be circular or elliptical. Moreover, although the surface of the board | substrate 11 was comprised from the plane area | region parallel to a horizontal surface, it is not restricted to this, A plane area | region, a slope area | region, and a curved surface area | region may be mixed. Thereby, various arrangement | positioning of the sensor element 12 is attained. The sensor elements 12 are alternately arranged in a grid shape, but the present invention is not limited to this arrangement, and as long as

adjacent sensor elements

12a and 12b are arranged without contact, other arrangements, for example, a staggered pattern, Also good.

Further, the arrangement state of the sensor element 12 with respect to the substrate 11 is parallel to the surface of the substrate 11, but is not limited thereto, and may be inclined with respect to the substrate 11. The sensor element 12 arranged directly on the substrate 11 may be inclined. Further, the sensor element 12 may be tilted by the substrate 11 when the sensor element 12 is arranged from the substrate 11. Further, both the sensor element 12 and the substrate 11 may be inclined. In short, it is only necessary that adjacent sensor elements 12 are arranged without contacting each other.

Further, the material of the substrate 11 is not limited to the pyroelectric material used in the above-described example (having spontaneous polarization without applying an electric field from the outside). Even a ferroelectric whose direction can be reversed by an external electric field can be used. Further, the upper and lower electrode patterns to be formed are not limited as long as electrical connection between the sensor element 12 and an external circuit or the like is possible, and the mounting method, wiring drawing, wiring material, or wiring shape is not limited. It is possible to change arbitrarily.

Some or all of the above embodiments may be described as in the following supplementary notes, but are not limited to the following.

(Appendix 1)
In an infrared detection sensor comprising a substrate and a plurality of infrared detection elements mounted and arranged on the substrate,
The plurality of infrared detection elements are:
A plurality of infrared detection elements located in a lower layer portion adjacent to the substrate;
A plurality of infrared detection elements located in an upper layer portion separated from the substrate,
When viewed from a direction perpendicular to the surface of the substrate, each infrared detection element located in the lower layer portion and each infrared detection element located in the upper layer portion are arranged so as to overlap each other in the vertical direction. ing,
An infrared detection sensor characterized by that.

(Appendix 2)
The infrared detection sensor according to appendix 1, wherein the plurality of infrared detection elements located in the lower layer portion and the plurality of infrared detection elements located in the upper layer portion are all arranged in a grid.

(Appendix 3)
Each infrared detecting element located in the upper layer part is located in the lower layer part, and is arranged at an intersection of a cross-shaped gap formed between four adjacent infrared detecting elements. 2. An infrared detection sensor according to 2.

(Appendix 4)
The infrared detection sensor according to any one of appendices 1 to 3, wherein each of the infrared detection elements includes at least one of a pyroelectric material and a ferroelectric material.

(Appendix 5)
The infrared detection sensor according to any one of supplementary notes 1 to 4, wherein the plurality of infrared detection elements are arranged such that light receiving surfaces thereof are parallel to the surface of the substrate.

(Appendix 6)
The infrared detection sensor according to any one of appendices 1 to 4, wherein the plurality of infrared detection elements are arranged such that light receiving surfaces thereof are inclined with respect to the surface of the substrate.

(Appendix 7)
The infrared detection sensor according to appendix 6, wherein the two adjacent infrared detection elements are arranged at different angles with respect to the surface of the substrate.

(Appendix 8)
The plurality of infrared detection elements located in the lower layer part are directly arranged with respect to the substrate, and the plurality of infrared detection elements located in the upper layer part are arranged via legs installed on the substrate. The infrared detection sensor according to any one of appendices 1 to 7, characterized in that:

(Appendix 9)
A plurality of recesses are formed in the substrate,
The plurality of infrared detection elements positioned in the lower layer portion are respectively disposed on the bottom surfaces of the respective recesses, and the plurality of infrared detection elements positioned in the upper layer portion respectively exclude the plurality of recesses in the substrate. Placed in the part,
The infrared detection sensor according to any one of appendices 1 to 7, characterized in that:

(Appendix 10)
Each of the infrared detection elements located in the lower layer part has an effective detection area relatively small with respect to the area of the main surface of each of the infrared detection elements. The infrared detection sensor described.

(Appendix 11)
Each infrared detection element is a pyroelectric body, and the pyroelectric body is made of a ceramic material. The infrared detection sensor according to any one of supplementary notes 1 to 10, wherein the pyroelectric body is made of a ceramic material.

(Appendix 12)
The infrared detection sensor according to appendix 11, wherein each of the infrared detection elements includes a lead zirconate titanate ceramic material as a ceramic material that functions as a pyroelectric body.

(Appendix 13)
The infrared detection sensor according to any one of appendices 1 to 12, wherein at least one selected from a metal material, a resin material, and a ceramic material is used as a material of the substrate.

(Appendix 14)
An electronic apparatus comprising the infrared detection sensor according to any one of appendices 1 to 13.

It should be noted that the present invention can be variously modified and modified without departing from the broad spirit and scope of the present invention. Further, the above-described embodiment is for explaining an example of the present invention, and does not limit the scope of the present invention.

This application is based on Japanese Patent Application 2010-197931 filed on September 3, 2010. The specification, claims, and entire drawings of Japanese Patent Application 2010-197931 are incorporated herein by reference.

According to the infrared detection sensor of the present invention, the amount of infrared light received by each sensor element (infrared detection element) is analyzed based on time-varying data that varies according to the movement of the human body that is the detection target. Sensitivity can be detected. Moreover, since it is detected as a mosaic image, the detected person cannot be specified, and personal information is protected. Therefore, it can be applied to an infrared sensor for human body detection in consideration of privacy.

11, 21

Substrate

12, 12a, 12b, 12c Sensor element (infrared detector)
DESCRIPTION OF SYMBOLS 13 Leg part 14 Optical diffraction element 15 Optical filter 16

Peripheral circuit part

17a, 17b Electrode 17c Light-receiving surface 17d Detection surface 18 Upper electrode layer 19 Lower electrode layer 21a Integrated substrate 21b Recessed part 21c

Integrated leg part

100, 101, 102 Pyroelectric infrared sensor (infrared array sensor)

Claims

In an infrared detection sensor comprising a substrate and a plurality of infrared detection elements mounted and arranged on the substrate,
The plurality of infrared detection elements are:
A plurality of infrared detection elements located in a lower layer portion adjacent to the substrate;
A plurality of infrared detection elements located in an upper layer portion separated from the substrate,
When viewed from a direction perpendicular to the surface of the substrate, each infrared detection element located in the lower layer portion and each infrared detection element located in the upper layer portion are arranged so as to overlap each other in the vertical direction. ing,
An infrared detection sensor characterized by that.
2. The infrared detection sensor according to claim 1, wherein the plurality of infrared detection elements located in the lower layer portion and the plurality of infrared detection elements located in the upper layer portion are all arranged in a grid.
Each infrared detecting element located in the upper layer part is located in an intersection of four cross-shaped gaps formed between four infrared detecting elements located in the lower layer part and adjacent to each other. Item 3. The infrared detection sensor according to Item 2.
The infrared detection sensor according to any one of claims 1 to 3, wherein each of the infrared detection elements includes at least one of a pyroelectric material and a ferroelectric material.
The infrared detection sensor according to any one of claims 1 to 4, wherein the plurality of infrared detection elements are arranged such that light receiving surfaces thereof are parallel to a surface of the substrate.
The infrared detection sensor according to any one of claims 1 to 4, wherein the plurality of infrared detection elements are arranged such that light receiving surfaces thereof are inclined with respect to a surface of the substrate.
The infrared detection sensor according to claim 6, wherein the two adjacent infrared detection elements are arranged at different angles with respect to the surface of the substrate.
The plurality of infrared detection elements located in the lower layer part are directly arranged with respect to the substrate, and the plurality of infrared detection elements located in the upper layer part are arranged via legs installed on the substrate. The infrared detection sensor according to any one of claims 1 to 7, wherein:
A plurality of recesses are formed in the substrate,
The plurality of infrared detection elements positioned in the lower layer portion are respectively disposed on the bottom surfaces of the respective recesses, and the plurality of infrared detection elements positioned in the upper layer portion respectively exclude the plurality of recesses in the substrate. Placed in the part,
The infrared detection sensor according to claim 1, wherein:
An electronic apparatus comprising the infrared detection sensor according to any one of claims 1 to 9.