JPWO2006112122A1 - Infrared sensor - Google Patents

Abstract

The present invention provides an infrared sensor that is small in size, has a wide infrared light receiving region (field of view), and has high detection accuracy, and further provides an infrared sensor that has high electromagnetic shielding properties and excellent electromagnetic wave resistance. An infrared sensor element 1, a package 2 having a box-like shape with an opening on one side and having a wiring pattern 11 inside, the infrared sensor element 1 being housed therein, and the entire opening of the package 2. The infrared sensor element 1 is disposed so as to cover the infrared sensor element 1 and has an optical filter that simultaneously functions as a lid for sealing the opening. Using a metal package, the optical filter and the metal package are electrically connected to improve anti-electromagnetic properties.

Description

  The present invention relates to an infrared sensor, and more particularly, to an infrared sensor with a wide viewing angle for sensing infrared rays, and an infrared sensor with a wide viewing angle and enhanced electromagnetic shielding properties.

  For example, as shown in FIG. 4, an infrared sensor element 53 in which a light receiving electrode 61 is disposed on a pyroelectric element 62 is used as one of the conventional infrared sensors used in human body detection and crime prevention equipment. A cylindrical metal case (cap) 55 provided with an optical filter 54 that supports the infrared sensor element 53 on the upper surface side and supports the infrared sensor element 53 on a metal base (stem) 52 having lead terminals 51. There is a stored infrared sensor with lead terminals. The infrared sensor further includes a support base 63 that supports the infrared sensor element 53, a substrate 64 on which a support base 63 is placed, and a surface on which necessary electrodes and circuits (not shown) are formed, and a bypass capacitor 65. FET 66, resistor 67, and the like.

  The input / output lead terminal 51 (51a, 51b) of the infrared sensor penetrates the metal stem 52 through the insulating material 60 and is connected to the circuit on the substrate 64, and is connected to the ground lead. The terminal 51 (51c) is electrically connected to the stem 52 (see Patent Document 1).

  However, in this conventional infrared sensor, the support base 63 and the support base 63 for supporting the infrared sensor element 53 are placed in the metal case 55 as described above, and necessary electrodes and circuits (see FIG. (Not shown) are provided with a substrate 64, a bypass capacitor 65, an FET 66, etc., which not only have a large number of parts and increase the size of the product, but also the manufacturing process becomes complicated and the manufacturing cost is reduced. There is a problem of causing an increase.

  Further, in the above conventional infrared sensor, the optical filter 54 is fitted into a part of the upper surface of the metal case 55, and the entire upper surface of the metal case 55 does not serve as a light receiving surface. There is a problem that becomes narrower.

  In addition, as shown in FIG. 5, for the purpose of downsizing, cost reduction, and productivity improvement, an upper substrate (for example, a silicon substrate) 71 having infrared transparency, and a lower substrate having an insulating portion and a conductive portion. An infrared sensor having a structure in which two of 72 are joined has been proposed (see Patent Document 2).

  The upper substrate 71 and the lower substrate 72 constituting the infrared sensor are provided with recesses 71a and 72a at positions facing each other, and a cavity 73 is formed by bonding both via a bonding layer 75, An infrared sensor element 74 is installed in the hollow portion 73. According to this infrared sensor, the infrared sensor element 74 is disposed in the cavity 73, and the cavity 73 has a low thermal conductivity. Therefore, the infrared sensor element 74 is affected by an external thermal influence. It is difficult to obtain high detection accuracy.

  However, in the case of the infrared sensor of Patent Document 2, the upper substrate 71, the lower substrate 72, the bonding layer 75, and the like are exposed from the side surfaces, and there is a problem that electromagnetic shielding properties (electromagnetic wave resistance) are likely to be insufficient. In addition, there is a problem in that it is not easy to form the recess 71a to be the cavity 73 in a substrate having infrared transparency such as silicon, and the cost is increased.

Further, in the case of the infrared sensor of Patent Document 2, the side surface of the cavity 73 does not stand vertically, so that it is difficult to secure an effective infrared light receiving region (field of view). There is a problem in that the degree of freedom of the structure is restricted because it is necessary to dispose it close to the upper substrate having infrared transparency.
Japanese Utility Model Publication No. 5-11464 JP 2001-174324 A

  The present invention solves the above-mentioned problems, and is an infrared sensor that is small in size, has a wide infrared light receiving region (field of view), has high detection accuracy, and has high electromagnetic shielding properties and excellent anti-electromagnetic properties. The purpose is to provide.

In order to solve the above problems, the infrared sensor of the present invention (Claim 1)
A surface-mounted infrared sensor comprising an infrared sensor element, a package in which the infrared sensor element is accommodated, and an optical filter that transmits infrared light of a predetermined wavelength,
An infrared sensor element;
A package corresponding to surface mounting, in which the infrared sensor element is housed, having a box shape with one surface opened, and a package in which a wiring pattern is disposed;
An optical filter that is not partially shielded and configured so that substantially the entire surface transmits infrared rays of a predetermined wavelength, and is disposed so as to cover the entire opening of the package, and the infrared sensor And an optical filter that simultaneously performs a function of causing the element to receive infrared light having a predetermined wavelength and a function as a lid for sealing the opening.

The infrared sensor of the present invention (Claim 2)
A surface-mounting infrared element including an infrared sensor element, a package in which the infrared sensor element is accommodated, and an optical filter that transmits infrared light of a predetermined wavelength,
An infrared sensor element;
A metal package corresponding to surface mounting, in which the infrared sensor element is housed, having a box shape with one surface opened, and a metal pattern having a wiring pattern disposed therein Package and
It is an optical filter that is not partially shielded and configured to transmit substantially infrared light of a predetermined wavelength, and is disposed so as to cover the entire opening of the metal package. An optical filter that simultaneously performs the function of causing the infrared sensor element to receive infrared light of a predetermined wavelength and the function of a lid that seals the opening; and
The optical filter and the metal package are electrically connected to each other.

  According to a third aspect of the present invention, there is provided the infrared sensor according to the second aspect, wherein an optical filter having a resistance of 1 MΩ / cm or less is used as the optical filter, and the optical filter is joined to the metal package. Thus, the optical filter and the package are electrically connected.

  According to a fourth aspect of the present invention, there is provided the infrared sensor according to the second aspect of the invention, wherein the optical filter includes a filter base material and a coating made of a low resistance material formed on the surface of the filter base material. The optical filter and the package are electrically connected to each other by bonding the optical filter to the metal package through the low resistance material.

  An infrared sensor according to a fifth aspect of the present invention is the configuration of the invention according to any one of the second to fourth aspects, wherein the infrared sensor is placed at a predetermined position of the metal package in such a manner that it is not electrically connected to the package by an insulator. The infrared sensor element disposed in the package is electrically connected to the outside through an external connection terminal for electrically connecting the infrared sensor element to the outside. It is characterized by being composed.

The infrared sensor according to the present invention (Claim 1) is a package corresponding to surface mounting in which an infrared sensor element and an infrared sensor element are housed, and has a box-like shape with one surface opened. A package having a wiring pattern disposed therein, and an optical filter that is not partially shielded and configured so that substantially the entire surface transmits infrared rays having a predetermined wavelength. The optical filter is disposed so as to cover the whole, and has an optical filter that simultaneously functions as an infrared sensor element for receiving infrared light of a predetermined wavelength and a function as a lid for sealing the opening. Since partial shielding is not performed and the entire surface is configured to transmit infrared rays, it is possible to widen the infrared light receiving region (field of view) and improve detection accuracy.
In addition, since the package includes a wiring pattern, it is possible to reduce the number of wiring patterns to be formed on other members, thereby reducing the size of the product and the number of components.
In addition, since the optical filter is joined to the package without any other parts, it is possible to reduce the size of the product and simplify the manufacturing process to reduce the cost. .
Furthermore, it is possible to further reduce the number of parts and reduce the size of the product by giving the package functions such as the stem and support part (base) that supports the infrared sensor element in the conventional infrared sensor. become.

  The infrared sensor according to the present invention (Claim 2) is a package corresponding to surface mounting in which an infrared sensor element and an infrared sensor element are housed, and has a box-like shape with one surface opened. A package having a wiring pattern disposed therein, and an optical filter that is not partially shielded and configured so that substantially the entire surface transmits infrared rays of a predetermined wavelength. An optical filter that is disposed so as to cover the entire opening and that simultaneously functions as a lid that seals the opening with a function of causing the infrared sensor element to receive infrared light having a predetermined wavelength. Because it is made of metal and the infrared sensor element is housed in a sealed space formed by an optical filter and a package that are electrically connected to each other, the electromagnetic shielding property is improved. It is possible to obtain a high infrared sensor of high reliability in resistance to electromagnetic wave characteristics.

Further, the optical filter used in the infrared sensor of the present invention (Claim 2) is not partially shielded, and the entire surface transmits infrared light of a predetermined wavelength. ) Can be widened to improve detection accuracy.
In addition, since the package includes a wiring pattern, it is possible to reduce the number of wiring patterns to be formed on other members, thereby reducing the size of the product and the number of components.
In addition, since the optical filter is joined to the package without any other parts, it is possible to reduce the size of the product and simplify the manufacturing process to reduce the cost. .
Furthermore, it is possible to further reduce the number of parts and reduce the size of the product by giving the package functions such as the stem and support part (base) that supports the infrared sensor element in the conventional infrared sensor. become.

Further, as in the infrared sensor of claim 3, in the configuration of the invention of claim 2, an optical filter having a resistance of 1 MΩ / cm or less is used as the optical filter, and the optical filter is joined to a metal package. As a result, the optical filter and the package can be easily and reliably conducted, and the present invention can be further effectively realized.
In addition, as a method of bonding the optical filter to the package, a method of bonding using a conductive adhesive or a method of mechanical bonding can be used, and the specific method is not particularly limited. .

Further, as in the infrared sensor of claim 4, in the configuration of the invention of claim 2, the optical filter is constituted by a filter base material and a film made of a low resistance material formed on the surface of the filter base material. When the optical filter and the package are electrically connected by bonding the optical filter to a metal package through a low resistance material, the degree of freedom in selecting the material constituting the optical filter itself is increased. It is possible to improve the characteristics of the infrared sensor from the viewpoint of the performance of the optical filter.
Examples of the filter substrate include single crystal silicon, quartz, sapphire, barium fluoride, spinel, and polyethylene.
The low resistance material to be applied to the surface of the optical filter is preferably a metal, particularly Ge (germanium).
In addition, as a method of applying a low resistance material to the surface of the optical filter, various thin film forming methods such as vapor deposition and sputtering can be applied, and there are special restrictions on the specific methods and conditions. Absent.
The optical filter having a resistance of 1 MΩ / cm or less as defined in claim 3 is achieved by a combination of a filter base material and a low resistance material.

  Further, in the configuration of the invention according to any one of claims 2 to 4, as in the infrared sensor according to claim 5, the insulator is not electrically connected to the package at a predetermined position of the metal package. When the infrared sensor element arranged in the package is electrically connected to the outside through the external connection terminal for electrically connecting the arranged outside and the infrared sensor element, It is possible to reliably obtain a surface-mounting type infrared sensor with high connection reliability and to reduce the size of the product.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the structure of the infrared sensor concerning one Example (Example 1) of this invention, (a) is sectional drawing, (b) is a perspective view. (a) is a figure which shows the visual field (corner) of the infrared sensor concerning Example 1 of this invention, (b) is the visual field of the infrared sensor of the structure which has arrange | positioned the optical filter in a part of upper surface of the conventional metal case. It is a figure which shows (corner). It is a figure which shows typically the structure of the infrared sensor concerning other Example (Example 2) of this invention, (a) is sectional drawing, (b) is a perspective view. It is a figure which shows the structure of the conventional infrared sensor. It is a figure which shows the structure of the other conventional infrared sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Infrared sensor element 1a Pyroelectric element 2 Package 2a Package opening 2b Inside (sealing space)
3 Optical filter 4 Insulating material 5 External connection terminal (external electrode)
6 Insulator (glass)
7 Conductive adhesive 10a, 10b Electrode (light receiving electrode)
11 Wiring pattern 12 Support part (base)
13 Bypass capacitor 14 FET
15 Resistance 22 Package

  The features of the present invention will be described in more detail below with reference to examples of the present invention.

FIG. 1A is a cross-sectional view schematically showing an infrared sensor according to one embodiment (Example 1) of the present invention, and FIG. 1B is a perspective view thereof.
This infrared sensor has an infrared sensor element 1 and a box-like shape with one surface (the upper surface side in FIG. 1) in which the infrared sensor element 1 is housed in the inside (sealing space) 2b, The wiring pattern 11 is provided therein, the infrared sensor element is accommodated therein, the metal package 2 corresponding to surface mounting, and the opening 2a of the package 2 are disposed so as to cover the whole, and the infrared sensor element 1 includes an optical filter 3 that simultaneously receives an infrared ray having a predetermined wavelength and a function as a lid for sealing the opening 2 a of the package 2.

  As the infrared sensor element 1, two electrodes (light receiving electrodes) 10a and 10b disposed on the surface of the pyroelectric element 1a polarized in the thickness direction are connected in series and in opposite polarities, and two light receiving elements are received. A so-called dual-type infrared sensor element is used, which is configured to eliminate external noise (such as temperature changes in the surrounding environment) that are simultaneously input to the electrodes 10a and 10b.

Further, as the package 2, a metal package such as 42Ni, phosphor bronze, brass, iron foil, iron, etc., which is box-shaped and has substantially the entire upper surface opened, is used. A part of the outer side is lined with an insulating material 4 such as glass or LCP resin (liquid crystal polymer). A wiring pattern 11 necessary for the configuration of the infrared sensor is formed on the surface of the insulating material 4.
The planar shape of the opening 2a of the package 2 is a rectangle.
Further, a support portion (base) 12 that supports the infrared sensor element 1 is disposed on the bottom surface of the package 2, and the infrared sensor element 1 is supported on the support portion (base) 12.

  Further, inside the package 2, a bypass capacitor 13, an FET 14, and a resistor 15 having a high resistance value necessary for configuring an infrared sensor are arranged so as to be in electrical communication with electrodes and wirings (not shown).

  In addition, in the infrared sensor of the first embodiment, an external connection insulated by an insulator (glass in this first embodiment) 6 so as not to conduct with the package 2 at a predetermined position of the metal package 2. A terminal (external electrode) 5 is provided. The infrared sensor element 1 disposed in the package 2 is configured to be electrically connected to the outside via a wiring pattern disposed in the package 2 or an external connection terminal (external electrode) 5. Has been.

As the optical filter 3, an optical filter made of single crystal silicon having a resistance of 1 MΩ / cm or less and transmitting infrared light of a predetermined wavelength is used as a filter base. It has a rectangular planar shape substantially corresponding to the opening 2a on the upper surface.
The optical filter 3 is bonded and fixed to the metal package 2 by the conductive adhesive 7, and the optical filter 3 and the package 2 are electrically connected.

  As the optical filter 3, an optical filter in which a metal film made of Ge (germanium) is applied as a low-resistance material film on the surface of the filter base by a method such as vapor deposition is used. Thus, the optical filter 3 and the package 2 can be electrically connected to each other by bonding to the metal package 2 with a conductive adhesive.

  In the infrared sensor configured as described above, the package 2 is made of metal, the optical filter 3 and the package 2 are electrically connected, and the infrared sensor element 1 is made of the metal package 2, Since it is housed in the sealed space 2b formed by the optical filter 3 that is electrically connected to the package 2, it is possible to improve electromagnetic shielding properties and realize excellent anti-electromagnetic properties.

  Further, the optical filter 3 used in the infrared sensor of Example 1 is not partially shielded, and is configured so that the entire surface transmits infrared rays. ) And an infrared sensor with high detection accuracy can be obtained.

  2A is a diagram schematically showing the field of view (corner) of the infrared sensor according to the first embodiment of the present invention, and FIG. 2B is optically shown in a part of the upper surface of the conventional metal case 55 for comparison. It is a figure which shows typically the viewing angle of the infrared sensor of the structure which has arrange | positioned the filter. 2A, the same reference numerals as those in FIG. 1 denote the same parts as in FIG. 1, and in FIG. 2B, the same reference numerals as in FIG. Show.

2 (a) and 2 (b), in the infrared sensor according to Example 1 of the present invention (FIG. 2 (a)), the entire opening 2a of the package 2 is covered with the optical filter 3, and the conventional sensor It can be seen that a wider viewing angle θ can be secured as compared with the infrared sensor (FIG. 2B) having a configuration in which the optical filter 54 is disposed on a part of the upper surface of the metal case 55.
In the present invention, a wider field of view can be ensured by increasing the angle between the bottom and side walls of the package 2 (θ1 (see FIG. 2A)).

  Further, since the package 2 includes the wiring pattern 11, it is possible to reduce the number of wiring patterns to be formed on other members, thereby reducing the size of the product and the number of parts.

  In addition, since the optical filter 3 can be joined to the package 2 without using other components, it is possible to reduce the size of the product and simplify the manufacturing process to reduce the cost. It becomes possible.

Further, since the package 2 includes the support portion (base) 12 that supports the infrared sensor element 1, no separate support member is required, and further, the number of parts is reduced and the product is downsized. It becomes possible.
Further, since the bottom of the package 2 functions as a stem of a conventional infrared sensor, the product can be downsized in this respect as well.

  FIG. 3A is a sectional view schematically showing a configuration of an infrared sensor according to another embodiment (Example 2) of the present invention, and FIG. 3B is a perspective view thereof.

The infrared sensor of Example 2 is
(1) A package 22 made of an insulating ceramic rather than a metal is used as a package in which the infrared sensor element 1 is housed.
(2) Unlike the case of the infrared sensor of the first embodiment, the inner surface of the package 2 is not provided with a structure lined with the insulating material 4, and the wiring pattern 11 is directly formed on the inner surface of the package 22. point,
(3) The external connection terminal (external electrode) 5 is not disposed in the package via an insulator such as glass as in the case of the infrared sensor of the first embodiment, but is made of an insulator ceramic. Although the configuration is different from that of the first embodiment in that it is directly formed on 22, the configuration is the same as that of the infrared sensor of the first embodiment in other points.
3A and 3B, the same reference numerals as those in FIGS. 1A and 1B indicate the same or corresponding parts.

In the infrared sensor of the second embodiment, since the package 22 is not made of metal, the electromagnetic wave resistance is inferior to that of the infrared sensor of the first embodiment, but the infrared sensor of the first embodiment is otherwise different. The same effect as the case can be obtained.
That is, the optical filter 3 used in the infrared sensor of Example 2 is not partially shielded, and the entire surface is configured to transmit infrared rays. ) And an infrared sensor with high detection accuracy can be obtained.
Further, since the package 22 includes the wiring pattern 11, a separate circuit board is not required, and the number of wiring patterns to be formed on other members is reduced, thereby reducing the product size and the number of components. Can be achieved.

  Further, since the optical filter 3 can be joined to the package 22 without using other components, the product can be downsized, and the manufacturing process can be simplified to reduce the cost. It becomes possible.

Further, since the package 22 includes the support portion (base) 12 that supports the infrared sensor element 1, no separate support member is required, and further, the number of parts is reduced and the product is downsized. It becomes possible.
Further, since the bottom of the package 22 functions as a stem of a conventional infrared sensor, the product can be downsized in this respect as well.

  In the second embodiment, the case where the package 22 made of an insulator ceramic is used has been described as an example. However, a package made of another insulator such as a glass epoxy resin can also be used.

  In the first and second embodiments, the case where the infrared sensor element is a so-called dual-type pyroelectric infrared sensor element using a pyroelectric element has been described as an example. There is no particular restriction on the type, and the present invention can be applied to an infrared sensor using a single type, a quad type, or various infrared sensor elements such as a thermopile and a photodiode.

  In the above embodiment, the case where an optical filter made of single crystal silicon is used has been described as an example. However, as the optical filter, for example, quartz, sapphire, barium fluoride, spinel, polyethylene can be used other than single crystal silicon. It is possible to use those made of various materials that transmit infrared rays.

  In addition, the present invention is not limited to the first and second embodiments in other respects, and various applications and modifications can be made within the scope of the invention with respect to the specific shape of the package. It is.

As described above, in the present invention, the optical filter is disposed so as to cover the entire opening of the package, and the optical filter has a function of causing the infrared sensor element to receive infrared light having a predetermined wavelength, and the opening is sealed. Since the function as a lid to be stopped is performed at the same time, it is possible to obtain an infrared sensor having a wide infrared light receiving region (field of view) and high detection accuracy. Further, since the package is provided with a wiring pattern, it is possible to reduce the number of wiring patterns to be formed on other members, thereby reducing the size of the product and the number of parts.
Further, by using a metal package and electrically connecting the optical filter and the metal package, it is possible to improve the anti-electromagnetic characteristics.
Therefore, the present invention can be widely used in the field of general-purpose infrared sensors used in human body detection, crime prevention equipment, and the like.

Claims (5)

A surface-mounted infrared sensor comprising an infrared sensor element, a package in which the infrared sensor element is accommodated, and an optical filter that transmits infrared light of a predetermined wavelength,
An infrared sensor element;
A package corresponding to surface mounting, in which the infrared sensor element is housed, having a box shape with one surface opened, and a package in which a wiring pattern is disposed;
An optical filter that is not partially shielded and configured so that substantially the entire surface transmits infrared rays of a predetermined wavelength, and is disposed so as to cover the entire opening of the package, and the infrared sensor An infrared sensor comprising: an optical filter that simultaneously performs a function of causing an element to receive infrared light having a predetermined wavelength; and a function of a lid that seals the opening. A surface-mounting infrared element including an infrared sensor element, a package in which the infrared sensor element is accommodated, and an optical filter that transmits infrared light of a predetermined wavelength,
An infrared sensor element;
A metal package corresponding to surface mounting, in which the infrared sensor element is housed, having a box shape with one surface opened, and a metal pattern having a wiring pattern disposed therein Package and
It is an optical filter that is not partially shielded and configured to transmit substantially infrared light of a predetermined wavelength, and is disposed so as to cover the entire opening of the metal package. An optical filter that simultaneously performs the function of causing the infrared sensor element to receive infrared light of a predetermined wavelength and the function of a lid that seals the opening; and
The infrared sensor, wherein the optical filter and the metal package are electrically connected.   An optical filter having a resistance of 1 MΩ / cm or less is used as the optical filter, and the optical filter and the package are electrically connected by bonding the optical filter to the metal package. Item 3. The infrared sensor according to Item 2.   The optical filter is composed of a filter base material and a coating made of a low resistance material formed on the surface of the filter base material, and the optical filter is placed in the metal package through the low resistance material. The infrared sensor according to claim 2, wherein the optical filter and the package are electrically connected by bonding.   Via an external connection terminal for electrically connecting the outside and the infrared sensor element disposed at a predetermined position of the metal package in such a manner that the insulator does not conduct with the package. The infrared sensor according to claim 2, wherein the infrared sensor element disposed in the package is configured to be electrically connected to the outside.

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