JP2007171058A - Infrared detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost infrared detector whose height has been reduced. <P>SOLUTION: The infrared detector A comprises: a printed-wiring board 10, where an infrared light receiving element 20, an IC component 21 in which the signal processing circuit of the infrared light receiving element 20 is integrated, and an externally mounted electronic component 22 are packaged; a metal case 1 for sealing at least the component packaging part of the printed-wiring board 10; and an infrared transmission filter 6 that is mounted to an opening window 5 provided at the part of the metal case 1 that opposes the light reception surface of the infrared light receiving element 20. The IC component 21 is die-bonded to the part of a back board 4 exposed from a through hole 13 formed on the printed-wiring board 10. A bonding pad provided on the surface of the printed-wiring board 10 makes continuity with that of the IC component 21 via a bonding wire made of a metal small-gauge wire. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an infrared detector.

Conventionally, as shown in FIGS. 8A and 8B, a pyroelectric infrared light receiving element 20, an IC component 21 in which a signal processing circuit of the infrared light receiving element 20 is integrated, and an external electronic component are combined into a three-dimensional circuit. An infrared detector having a structure in which a vertical mounting structure 31 mounted on a molded substrate (MID) 30 is erected on a stem 32 and covered with a metal cap 33 is provided (see, for example, Patent Document 1).
Japanese Patent No. 3211074

  The infrared detector having the above configuration is tall because the vertical mounting structure 31 is erected on the stem 32. When the infrared detector is mounted on an electric device to be mounted on a wall surface, the infrared detector is incorporated. There was a problem that the design protruded due to the protruding part.

  Further, since the three-dimensional circuit molded substrate 30 is used, there is a problem that the manufacturing process is complicated and the cost is increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a low-cost infrared detector realizing a low profile.

  In order to achieve the above object, the present invention provides an infrared light receiving element, an IC component in which a signal processing circuit of the infrared light receiving element is integrated, and a printed wiring board on which at least the infrared light receiving element and an external electronic component are mounted. And a metal case that encloses at least a component mounting part of the printed wiring board, and an infrared transmission filter that is attached to an opening window provided in a part of the metal case facing a light receiving surface of the infrared light receiving element, Bonding of the IC component and a bonding pad provided on the surface of the printed wiring board, wherein the IC component is disposed in either a recess provided on the surface of the printed wiring board or a through hole formed in the printed wiring board. The pad is electrically connected to the pad through a bonding wire made of a fine metal wire.

  According to the present invention, since the infrared light receiving element and the external electronic component are mounted on the printed wiring board, the manufacturing process is simple, the manufacturing cost can be reduced, and the low profile can be realized. Is disposed in either the concave portion or the through hole of the printed wiring board, the thickness of the infrared detector can be reduced by the depth of the concave portion or the thickness of the printed wiring board, and the height can be further reduced. There is an effect. In addition, since the component mounting portion of the printed wiring board is enclosed in the metal case, the noise resistance against electrical external noise is improved and the reliability is improved.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
Embodiment 1 of this invention is demonstrated based on FIGS. 1-3. FIG. 1A is an exploded perspective view of the infrared detector A of the present embodiment, and FIG. 1B is a perspective view of the state in which the front plate 3 is removed. 20, a printed wiring board 10 on which an IC component 21 in which a signal processing circuit of the infrared light receiving element 20 is integrated and an external electronic component 22 are mounted is housed. Here, the infrared detector A is for detecting the presence or absence of a person in the detection area by detecting infrared rays radiated from a human body in the detection area by the pyroelectric infrared light receiving element 20, for example. 21 is formed with a circuit for processing the detection output of the infrared light receiving element 20 and outputting a human body detection signal indicating the presence or absence of a person.

  The case 1 includes a square frame-shaped frame body 2, and a metal front plate 3 and a back plate 4 that are attached to the frame body 2 so as to close the openings on the front side and the back side of the frame body 2. Composed. An opening window 5 is formed on the front plate 3 at a portion where the infrared light receiving element 20 faces, and a plate-like infrared transmission filter 6 having a light transmission property with respect to infrared rays is attached to the opening window 5. Yes. Thus, the infrared light entering the case 1 through the infrared transmission filter 6 is incident on the light receiving surface of the infrared light receiving element 20.

  On the other hand, the printed wiring board 10 has a narrow projecting portion 12 projecting from one side of the substantially rectangular component mounting portion 11 and has a substantially convex shape in plan view, and is adhered to the surface of the back plate 4. Adhesive and fixed using an agent. The front end side of the protruding portion 12 protrudes to the outside of the back plate 4 and protrudes to the outside of the case 1 through a notch 7 provided on the lower surface of the frame body 2. And the lead terminal 23 is mounted in the site | part exposed to the outer side of the case 1 in the protrusion part 12. As shown in FIG.

  An infrared light receiving element 20 and an external electronic component 22 are mounted on the surface (surface on the front plate 3 side) of the printed wiring board 10. Further, a through hole 13 into which the IC component 21 is inserted is formed at the center of the printed wiring board 10, and the IC component 21 is die-bonded to the portion of the back plate 4 exposed from the through hole 13, and the printed wiring The bonding pad provided on the surface of the plate 10 and the bonding pad of the IC component 21 are electrically connected via a bonding wire (not shown) made of a fine metal wire. In the printed wiring board 10, a through hole 14 having a planar shape smaller than that of the infrared light receiving element 20 is formed at the mounting portion of the infrared light receiving element 20. It is mounted to bridge between both side edges.

  Next, the manufacturing process of the infrared detector A will be described with reference to FIGS. First, an epoxy adhesive 15 and a silver paste 16 are applied to the surface of the back plate 4 (see FIG. 2A), the printed wiring board 10 is placed on the surface of the back plate 4, and the adhesive 15 is attached. The printed wiring board 10 is bonded and fixed to the back plate 4 by curing (see FIG. 2B). At this time, a ground pattern (not shown) provided on the back surface of the printed wiring board 10 is electrically connected to the metal back plate 4 via the silver paste 16.

  And after apply | coating the die bonding paste 17 to the site | part of the backplate 4 exposed from the through-hole 13 of the printed wiring board 10 (refer FIG.2 (c)), die the IC component 21 to the printed wiring board 10 through the through-hole 13. FIG. Bonding is performed, the die bonding paste 17 is cured, and the IC component 21 is fixed to the printed wiring board 10. The bonding pad of the printed wiring board 10 and the bonding pad of the IC component 21 are electrically connected via a bonding wire (not shown). (See FIG. 2 (d)).

  Thereafter, a silver paste is applied to an electrode (not shown) provided at the component mounting position of the printed wiring board 10 (see FIG. 2E), the electronic component 22 is mounted to cure the silver paste, and the through hole First, silver paste is applied to the peripheral electrode 14 (see FIG. 2 (f)), the infrared light receiving element 20 is mounted and the silver paste is cured, and then the silver paste is further applied to the electrode of the infrared light receiving element 20. Next, the mounting of the component is completed by curing the silver paste (see FIG. 2G).

  Next, as shown in FIG. 3A, an epoxy adhesive 18 is applied to the peripheral edge of the front surface of the back plate 4 except for the portion where the protruding portions 12 of the printed wiring board 10 overlap, and the front surface of the back plate 4 After the frame 2 is overlapped on the side and the frame 2 is bonded and fixed (see FIG. 3B), an epoxy adhesive 19 is applied to the upper surface of the frame 2 (see FIG. 3C). Assembling of the case 1 is completed by stacking the front plate 3 to which the infrared transmission filter 6 is fixed on the front side of the body 2 and bonding and fixing the front plate 3 (see FIG. 3D). Thereafter, an epoxy adhesive is applied to the notch 7 provided in the frame 2 and cured to seal the case 1, and then lead to the through hole 12 a provided in the projecting portion 12 protruding from the notch 7 to the outside of the case 1. The terminal 23 is fixed by press-fitting (so-called press-fit connection), and the assembly of the infrared detector A is completed.

  The infrared detector A of the present embodiment has the above-described configuration, and since the infrared light receiving element 20, the IC component 21, and the external electronic component 22 are mounted on the printed wiring board 10, it is manufactured. The process is simple and the manufacturing cost can be reduced, and the height can be reduced. Since the mounting components (infrared light receiving element 20, IC component 21, and external electronic component 22) are all mounted on the same surface of the printed wiring board 10, they can be formed thinner than in the case of double-side mounting, and infrared detection is possible. The height of the vessel A can be reduced.

  In addition, since the IC component 21 is disposed in the through hole 13 provided in the printed wiring board 10 (that is, die-bonded to the portion of the back plate 4 (case 1) exposed from the through hole 13), the printed wiring Since the thickness of the infrared detector A can be reduced by the thickness of the plate 10 and the infrared detector A can be further reduced in height, the infrared detector A can be used even when the infrared detector A is incorporated in an electrical device. As a result, the thickness of the assembly part does not increase, and the design is not impaired. In this embodiment, the IC component 21 is disposed in the through hole 13 provided in the printed wiring board 10. However, the IC component 21 may be mounted in a recess formed on the component mounting surface of the printed wiring board 10. The thickness of the infrared detector A can be reduced by the depth of the recess, and the height can be reduced.

  Further, since the infrared light receiving element 20 is mounted so as to bridge the peripheral portion of the through-hole 14 provided in the printed wiring board 10, the infrared light receiving element 20 is thermally insulated, and the sensitivity of the infrared light receiving element 20. Can be improved.

  Moreover, since the component mounting part 11 of the printed wiring board 10 is enclosed in the metal case 1, the noise resistance against electrical external noise can be improved and the reliability can be improved.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. In the first embodiment described above, a part of the printed wiring board 10 is protruded outside the case 1 and the lead terminal 23 is attached to the protruding portion. However, in this embodiment, the printed wiring board 10 is provided inside the case 1. The whole is stored. In addition, since the basic structure of the infrared detector A is the same as that of Embodiment 1, the same code | symbol is attached | subjected to a common component and the description is abbreviate | omitted.

  As shown in FIGS. 4A and 4B, the case 1 includes a flat box-shaped metal cover 8 whose lower surface (rear surface) is opened, and a metal back plate that is attached to the opening of the cover 8. 4 and. The back plate 4 is provided with three insertion holes 4a through which the three lead terminals 23 fixed to the printed wiring board 10 are inserted. On the upper surface (front surface) of the cover 8, an opening window 9 is formed at a portion facing the infrared light receiving element 20, and a plate-like infrared transmission filter 9 having translucency for infrared rays is formed in the opening window 9. It is attached. Thus, the infrared light incident on the inside of the case 1 through the infrared transmission filter 9 enters the light receiving surface of the infrared light receiving element 20.

  On the other hand, the printed wiring board 10 has a rectangular plate shape and is bonded and fixed to the front side of the back plate 4 using an adhesive. An infrared light receiving element 20 and an external electronic component 22 are surface-mounted on the surface of the printed wiring board 10 (surface opposite to the back plate 4). Further, a through hole 13 into which the IC component 21 is inserted is formed at the center of the printed wiring board 10, and the IC component 21 is die-bonded to the portion of the back plate 4 exposed from the through hole 13, and the printed wiring The bonding pad provided on the surface of the plate 10 and the bonding pad of the IC component 21 are electrically connected via a bonding wire (not shown) made of a fine metal wire. In the printed wiring board 10, a through hole 14 having a planar shape smaller than that of the infrared light receiving element 20 is formed at the mounting portion of the infrared light receiving element 20. It is mounted so as to bridge between both side edges.

  Next, the manufacturing process of this infrared detector A will be described with reference to FIGS. First, as shown in FIG. 5A, the lead terminal 23 is fixed by press-fitting into a through hole 10a provided in the printed wiring board 10 (so-called press-fit connection). An epoxy adhesive 15 is applied to the front side of the back plate 4 (see FIG. 5B), and the printed wiring board 10 is placed on the front side of the back plate 4 with the lead terminals 23 inserted through the insertion holes 4a. Then, the adhesive 15 is cured to fix the printed wiring board 10 to the back plate 4 (see FIG. 5C). Then, from the back side of the back plate 4, silver paste 24 is applied only to the insertion holes 4a through which the lead terminals 23 electrically connected to the ground pattern of the printed wiring board 10 are inserted (see FIG. 5D). ) By curing the silver paste, the ground pattern of the printed wiring board 10 is electrically connected to the back plate 4 made of a metal plate. Further, the epoxy adhesive 25 is applied to the three insertion holes 4a from the back side of the back plate 4 (see FIG. 5E), and the adhesive 25 is cured to seal the insertion holes 4a. (See FIG. 5 (f)).

  Thereafter, after the die bonding paste 17 is applied to the portion of the back plate 4 exposed from the through hole 13 of the printed wiring board 10 (see FIG. 6A), the IC component 21 is die bonded to the back plate 4 through the through hole 13. Then, the die bonding paste 17 is cured to fix the IC component 21 to the back plate 4, and the bonding pad of the printed wiring board 10 and the bonding pad of the IC component 21 are made conductive via a bonding wire (not shown). (Refer FIG.6 (b)). Then, a silver paste is applied to an electrode (not shown) provided at a component mounting position of the printed wiring board 10 (see FIG. 6C), and the electronic component 22 is mounted to cure the silver paste (FIG. 6 ( d)).

  Next, silver paste is primarily applied to the peripheral electrode of the through hole 14 in the printed wiring board 10 (see FIG. 7A), and the infrared light receiving element 20 is bridged between the peripheral parts of the through hole 14. After mounting and curing the silver paste, the silver paste is further applied to the electrode of the infrared light receiving element 20 to cure the silver paste, thereby completing the component mounting (see FIG. 7B). .

  Thereafter, as shown in FIG. 7C, the cover 8 having the infrared transmission filter 9 fixed to the opening window 9 is attached to the upper surface side of the back plate 4, and the flange portion 8a and the back plate 4 of the cover 8 are attached. The assembly of the infrared detector A is completed by welding (see FIG. 7D).

  The infrared detector A of the present embodiment has the above-described configuration, and since the infrared light receiving element 20, the IC component 21, and the external electronic component 22 are mounted on the printed wiring board 10, it is manufactured. The process is simple and the manufacturing cost can be reduced, and the height can be reduced. Since the mounting components (infrared light receiving element 20, IC component 21, and external electronic component 22) are all mounted on the same surface of the printed wiring board 10, they can be formed thinner than in the case of double-side mounting, and infrared detection is possible. The height of the vessel A can be reduced.

  In addition, since the IC component 21 is disposed in the through hole 13 provided in the printed wiring board 10 (that is, die-bonded to the portion of the back plate 4 (case 1) exposed from the through hole 13), the printed wiring Since the thickness of the infrared detector A can be reduced by the thickness of the plate 10 and the infrared detector A can be further reduced in height, the infrared detector A can be used even when the infrared detector A is incorporated in an electrical device. As a result, the thickness of the assembly part does not increase, and the design is not impaired. In this embodiment, the IC component 21 is disposed in the through hole 13 provided in the printed wiring board 10. However, the IC component 21 may be mounted in a recess formed on the component mounting surface of the printed wiring board 10. The thickness of the infrared detector A can be reduced by the depth of the recess, and the height can be reduced.

  Further, since the infrared light receiving element 20 is mounted so as to bridge the peripheral portion of the through-hole 14 provided in the printed wiring board 10, the infrared light receiving element 20 is thermally insulated, and the sensitivity of the infrared light receiving element 20. Can be improved.

  Moreover, since the printed wiring board 10 is enclosed in the case 1 made of metal, the noise resistance against electrical external noise is improved, and the reliability can be enhanced.

The infrared detector of Embodiment 1 is shown, (a) is a disassembled perspective view, (b) is a perspective view of the state which removed the surface plate. (A)-(g) is explanatory drawing of a manufacturing process same as the above. (A)-(e) is explanatory drawing of a manufacturing process same as the above. The infrared detector of Embodiment 2 is shown, (a) is a disassembled perspective view, (b) is a perspective view of the state which removed the cover. (A)-(f) is explanatory drawing of a manufacturing process same as the above. (A)-(d) is explanatory drawing of a manufacturing process same as the above. (A)-(d) is explanatory drawing of a manufacturing process same as the above. The conventional infrared detector is shown, (a) is an exploded perspective view, (b) is an external perspective view.

Explanation of symbols

A Infrared detector 1 Metal case 4 Back plate 5 Open window 6 Infrared transmission filter 10 Printed wiring board 13 Through hole 20 Infrared light receiving element 21 IC component 22 Electronic component

Claims (1)

An infrared light receiving element; an IC component in which a signal processing circuit of the infrared light receiving element is integrated; a printed wiring board on which at least the infrared light receiving element and an external electronic component are mounted; and at least a component mounting portion of the printed wiring board. A metal case to be sealed; and an infrared transmission filter attached to an opening window provided in a portion of the metal case facing a light receiving surface of the infrared light receiving element, wherein the IC component is disposed on a surface of the printed wiring board. A bonding wire made of a fine metal wire is disposed between the bonding pad provided on the surface of the printed wiring board and the bonding pad of the IC component, which is disposed in either the recessed portion provided or the through hole formed in the printed wiring board. An infrared detector characterized by being conducted through.

Images