JP2007158184A - Solid photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an bedewing more effectively in a solid photographing device, where its chip-form solid photographing element is sealed in an airtight manner by its sealing package. <P>SOLUTION: The sealing package 10 for sealing the solid photographing element 20, in an airtight manner comprises a package body 11, leads 12, and heat radiating plates 13. The package body 11 is formed in the shape of a recess to surround the top surface of the solid photographing element 20 which includes its light-receiving surface 21 so as to surround its respective side surfaces. Each lead 12 is fastened to each inner wall-surface of the package body 11 and is connected electrically with each electrode pad 22 of the solid photographic element 20. Each heat-radiating plate 13 is fastened to each inner wall-surface of the package body 11 and is abutted against a portion of the top surface of the solid photographic element 20, wherefrom its light-receiving surface 21 is excluded. The sealing package 10 seals in an airtight manner the solid photographic element 20 by filling a resin into the space between the solid photographic element 20 and the package body 11 wherefrom at least its light-receiving surface 21 is excluded. The heat-radiating plates 13 conduct the heat generated from the solid photographic element 20 to the package body 11 and reduces the temperature difference between the solid photographing element 20 and the sealing package 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device in which a chip-shaped solid-state imaging device is hermetically sealed by a sealing package.

  As a sealing method for sealing a chip-shaped solid-state imaging device such as a CCD (Charge Coupled Device) image sensor, there is an airtight sealing method. In general, a concave portion for storage is integrally formed on a package body that is a base of a sealed package, and a solid-state image sensor is fixed to the bottom surface of the concave portion so that a light receiving surface faces upward, and then the opening of the concave portion is formed. Sealing is performed by bonding a transparent lid (lid) to the package body using an adhesive so as to close the package.

  By the way, in such a hermetic sealing type solid-state imaging device, there is a problem that condensation occurs on the light receiving surface of the solid-state imaging element. Regarding the prevention of this dew condensation, Patent Document 1 discloses a technique of filling a transparent resin between the lid and the light receiving surface, but this causes a problem that the light transmittance is reduced and the sensitivity is lowered. is there.

Therefore, as other methods, a technique for preventing moisture from entering the sealed space from the outside (see Patent Documents 2 and 3) and a technique for reducing the temperature of the solid-state imaging element that generates heat (see Patent Document 4) are proposed. ing. In Patent Document 2, by forming irregularities in the joint portion of the lid of the package body, the joint area is expanded and the moisture resistance (performance to prevent the ingress of moisture from the outside) is improved. In Patent Document 3, the moisture resistance is improved and moisture remaining in the sealed space is reduced by bonding the lid of the package body using a hygroscopic adhesive and a low moisture-permeable adhesive. I am letting. In Patent Document 4, the temperature of the solid-state imaging device is lowered by providing a metal radiating fin on the outer surface of the package body.
Japanese Patent Laid-Open No. 6-151643 Japanese Patent Laid-Open No. 10-247695 JP-A-11-145337 JP 2004-146530 A

  An object of the present invention is to provide a solid-state imaging device capable of preventing dew condensation more effectively than the technique described in the above-mentioned conventional document.

  In order to achieve the above object, the solid-state imaging device of the present invention is a solid-state imaging device comprising a rectangular chip-shaped solid-state imaging device and a sealed package for hermetically sealing the solid-state imaging device. Is an upper surface including the light receiving surface of the solid-state imaging device, and a package body formed in a concave shape so as to surround each side surface thereof, and is fixed to the package body and electrically connected to an electrode pad of the solid-state imaging device. And a heat sink fixed to the package body and contacting a part of the upper surface of the solid-state image sensor excluding the light-receiving surface, and at least the solid-state image sensor and the package body excluding the light-receiving surface The solid-state imaging device is hermetically sealed by filling a resin between the two. Thereby, the temperature difference between the solid-state imaging device and the sealed package is reduced.

  In addition, it is preferable that the said heat sink is metal. Moreover, it is preferable that the said heat sink is provided with the frame-shaped part formed so that it might contact | abut the circumference | surroundings of the said light-receiving part. Further, it is preferable that when the lead is bonded to the mounting substrate, the heat radiating plate contacts the mounting substrate and releases heat. These improve heat dissipation.

  Moreover, it is preferable that the recessed part is provided in the surface of the said heat sink which contacts the said resin, or the said package main body. Thereby, the adhesiveness of resin and a package main body increases.

  The resin preferably covers the back surface of the solid-state image sensor. Moreover, it is preferable that the printing board on which predetermined information was printed is affixed on the surface of the said resin which covers the back surface of the said solid-state image sensor.

  Further, it is preferable that the solid-state imaging device is a CCD image sensor, and the heat sink is in contact with an output amplifier. The output amplifier generates a large amount of heat, which increases heat dissipation.

  According to the solid-state imaging device of the present invention, it is possible to reduce the temperature difference between the solid-state imaging device and the sealed package and prevent condensation. In addition, since the path from the light receiving surface to the outside passes through the side portion of the solid-state imaging element, and the side portion is filled with resin, it is possible to reduce the ingress of moisture causing condensation. Furthermore, since the heat sink abuts on the upper surface of the solid-state imaging device and functions as a mounting position reference plate in the vertical direction of the solid-state imaging device, the mounting accuracy of the solid-state imaging device with respect to the sealed package can be improved.

  In FIG. 1, a sealed package 10 for hermetically sealing a rectangular chip-shaped solid-state imaging device 20 includes a package body 11 made of transparent plastic, a plurality of leads 12 and a heat radiating plate 13 fixed to the package body 11. Consists of. The package main body 11 is a concave lid member composed of a rectangular flat plate-shaped upper portion and four rectangular flat plate-shaped side portions surrounding the rectangular flat plate-shaped upper portion, and includes an upper surface including the light receiving surface 21 of the solid-state imaging device 20 and each side surface thereof. Enclose. The material of the package body 11 is not limited to plastic, and may be glass. The package body 11 may be opaque if at least a portion facing the light receiving surface 21 is transparent so that light enters the light receiving surface 21.

  The lead 12 is made of metal (copper alloy type, nickel alloy type, etc.), and includes a strip-like base portion 12c, and an inner lead portion 12a and an outer lead portion 12b that are bent substantially perpendicularly to the base portion 12c. . The inner lead portion 12a is fixed to the inner wall surface of the upper portion of the package body 11, the base portion 12c is fixed to the inner wall surface of the side of the package body 11, and the outer lead portion 12b is fixed to the lower end surface thereof.

  The heat radiating plate 13 is made of metal (copper alloy type, nickel alloy type, etc.), and is bent at a substantially right angle to the rectangular frame-shaped part 13b in which the rectangular opening 13a is formed, and the frame-shaped part 13b. It consists of two side portions 13c and an end portion 13d bent at a substantially right angle with respect to the end portions of each side portion 13c. The frame portion 13b is fixed to the inner wall surface of the upper portion of the package body 11, the side portion 13c is fixed to the inner wall surface of the side of the package body 11 where the leads 12 are not formed, and the end portion 13d is fixed to the lower end surface thereof. Yes.

  Each lead 12 is disposed so as to correspond to each electrode pad 22 formed on the upper surface of the solid-state imaging device 20. The heat radiating plate 13 is disposed so as to correspond to a portion excluding the light receiving surface 21 and the electrode pad 22 formed on the upper surface of the solid-state imaging device 20, and exposes the light receiving surface 21 from the rectangular opening 13a. The solid-state imaging device 20 is a silicon semiconductor chip, and a CCD image sensor, a CMOS image sensor, or the like is configured as the imaging device.

  FIG. 2 shows a cross section of a package unit (solid-state imaging device) 2 formed by hermetically sealing the solid-state imaging element 20 with a sealing package 10. 2A is a vertical cross-sectional view along the X direction in FIG. 1, and FIG. 2B is a vertical cross-sectional view along the Y direction in FIG.

  The solid-state imaging device 20 is fixed in the sealed package 10 by bonding the electrode pad 22 to the inner lead portion 12a via the conductive adhesive 30, and the upper surface of the solid-state imaging device 20 is disposed on the heat radiating plate 13. Is in contact with the frame-like portion 13b. A resin 31 is filled between the solid-state imaging device 20 and the sealed package 10 (at least excluding the light receiving surface 21). The resin 31 also covers the back surface of the solid-state imaging device 20. A plastic or metal printing plate 32 on which predetermined information (product name, lot number, wafer number, etc.) is printed (marked) is attached to the back surface side of the solid-state imaging device 20 through a resin 31. It has been. The resin 31 is preferably a low moisture-permeable resin in order to prevent moisture from entering.

  The outer lead portion 12 b is exposed to the outside and functions as an external terminal of the package unit 2. The outer lead portion 12b is connected by soldering or the like when the package unit 2 is mounted on a predetermined mounting substrate (not shown). Further, the end 13d of the heat radiating plate 13 is also exposed to the outside, and when the package unit 2 is mounted on the mounting board, the end 13d contacts the mounting board.

  Since the package unit 2 transmits heat generated in the solid-state image pickup device 20 by the image pickup operation to the package body 11 through the heat radiating plate 13, and this heat is released to the mounting substrate through the heat radiating plate 13, the solid-state image pickup device. The temperature difference between 20 and the sealed package 10 can be reduced, and condensation can be prevented. Further, the path from the light receiving surface 21 to the outside is long because it passes through the side portion of the solid-state imaging device 20, and the path is filled with the resin 31, so moisture hardly enters the light receiving surface 21. This structure also contributes to prevention of condensation.

  Further, as shown in FIG. 2A, the frame-like portion 13b of the heat radiating plate 13 is formed to be thicker than the inner lead portion 12a of the lead 12, and contacts the upper surface when the solid-state imaging device 20 is attached. The heat sink 13 functions as an attachment position reference plate in the vertical direction of the solid-state image sensor 20. Thereby, the mounting accuracy in the vertical direction is improved, and the flatness (chip flatness) of the solid-state imaging device 20 with respect to the sealed package 10 is improved.

  In addition, it is preferable that the heat sink 13 is black or the surface is coated with black so that reflection of light is prevented and unnecessary light does not enter the light receiving surface 21. When the solid-state imaging device 20 is configured as a CCD image sensor, the amount of heat generated during the imaging operation is the largest in an output amplifier (not shown) that converts a signal charge into a voltage signal. It is preferable to be disposed so as to abut on the output amplifier.

  FIG. 3 shows an example in which a recess 33 is provided on the surface of the heat dissipation plate 13 in contact with the resin 31. The recess 33 improves the adhesion between the heat radiating plate 13 and the resin 31. The outer shape of the recess 33 may be an appropriate shape such as a circle, a rectangle, or a groove. The recess 33 may be provided on the surface of the package body 11 as long as it is a part that contacts the resin 31.

  Next, a method for manufacturing the package unit 2 (a method for sealing the solid-state imaging element 20) will be described with reference to FIG. As shown in FIG. 4A, first, a conductive adhesive 30 is applied to the inner lead portion 12a of the lead 12 with the opening of the sealed package 10 facing upward. Next, as shown in FIG. 4B, the light receiving surface 21 of the solid-state imaging device 20 faces downward, and the electrode pads 22 are stacked in the sealed package 10 while being aligned so as to correspond to the inner lead portions 12a. . At this time, the surface of the solid-state imaging device 20 comes into contact with the frame-like portion 13 b of the heat radiating plate 13.

  Next, after the conductive adhesive 30 is cured and the solid-state imaging device 20 is fixed to the sealed package 10, as shown in FIG. 4C, the solid-state imaging device 20 and the sealed package 10 are at least (at least The resin 31 is filled so as to cover the back surface of the solid-state imaging device 20 and the printing plate 32 is attached to the surface of the filled resin 31. Then, after the resin 31 is cured, printing is performed on the printing plate 32 with a laser or ink.

  In this method, the light-receiving surface 21 of the solid-state imaging device 20 is hermetically sealed at an early stage of the process, so that dust contamination on the light-receiving surface 21 is reduced and scratches caused by the process are prevented.

  In the above embodiment, the inner lead portion 12a and the electrode pad 22 are bonded using the conductive adhesive 30, but the present invention is not limited to this, and bonding may be performed using solder or the like.

  It is also effective to use an anisotropic conductive adhesive for this joining. Instead of applying the conductive adhesive 30 in FIG. 4A, an anisotropic conductive adhesive is applied to the region 40 shown in FIG. 5 so as to straddle the plurality of inner lead portions 12a. Similarly, the electrode pad 22 is pressed onto the inner lead portion 12a via an anisotropic conductive adhesive. By this pressing, the anisotropic conductive adhesive is conductive in the vertical direction, and the corresponding inner lead portion 12a and the electrode pad 22 are electrically connected. Since the anisotropic conductive adhesive does not have conductivity in the lateral direction, the inner lead portions 12a or the electrode pads 22 are not short-circuited. By using an anisotropic conductive adhesive, the above-described adhesive application process is simplified.

  It is also effective to use an anisotropic conductive tape having conductivity only in the thickness direction in place of the anisotropic conductive adhesive. This anisotropic conductive tape may be attached to the region 40 shown in FIG. 5 so as to straddle the plurality of inner lead portions 12a, and the solid-state imaging device 20 having bumps formed on the electrode pads 22 with solder or the like may be pressed. .

  Furthermore, in order to ensure the contact and heat dissipation between the heat sink 13 and the solid-state image sensor 20, an anisotropic conductive tape is attached to the surface of the frame-like portion 13b that contacts the upper surface of the solid-state image sensor 20. Also good. It is also effective to apply an insulating adhesive having thermal conductivity and low moisture permeability to the surface of the frame portion 13b.

  Moreover, in the said embodiment, although the printing board 32 is provided in the back surface side of the solid-state image sensor 20, the printing board 32 does not necessarily need to be provided. When the printing plate 32 is not provided, printing may be performed directly on the surface of the filled resin 31 with a laser or the like.

  Moreover, in the said embodiment, although the lead | read | reed 12 and the heat sink 13 are arrange | positioned along the inner wall of the sealing package 10, and the lower end part of the sealing package 10 is made into the mounting surface with a board | substrate, the lead 12 and the heat sink 13 The shape and the arrangement method on the package body 11 may be changed as appropriate.

  FIG. 6 shows a modification of the lead 12 and the heat radiating plate 13 in which the base portion 12 c of the lead 12 and the side portion 13 c of the heat radiating plate 13 are exposed on the outer surface of the sealed package 10. The above is an example of a surface mount package, and FIG. 7 further illustrates a DIP (Dual Inline Package), which is a type of insertion mount package, in which the outer lead portion 12b of the lead 12 is straightened downward. is doing.

It is an external appearance perspective view of a solid-state image sensor and its sealing package. It is a longitudinal cross-sectional view of a package unit, (A) shows the cross section which follows the X direction of FIG. 1, (B) shows the cross section which follows the Y direction of FIG. It is sectional drawing which shows the example which provided the recessed part in the surface of the heat sink. It is sectional drawing explaining the manufacturing method of a package unit, (A) shows the application | coating process of an adhesive agent, (B) shows the alignment process of a solid-state image sensor, (C) shows the filling process of resin. It is a perspective view which shows the application | coating area | region of an anisotropic conductive adhesive, and the sticking area | region of an anisotropic conductive tape. It is a longitudinal cross-sectional view which shows the example which exposed the lead | read | reed and the heat sink to the outer surface of the sealing package, (A) is a cross section in the X direction of FIG. 1, (B) is a cross section in the Y direction of FIG. Show. It is a longitudinal cross-sectional view which shows the example which extended the outer lead part of the lead | read | reed downward, (A) is a cross section along the X direction of FIG. 1, (B) shows the cross section along the Y direction of FIG.

Explanation of symbols

2 Package unit (solid-state imaging device)
DESCRIPTION OF SYMBOLS 10 Sealing package 11 Package body 12 Lead 12a Inner lead part 12b Outer lead part 12c Base part 13 Heat sink 13a Rectangular opening 13b Frame-like part 13c Side part 13d End part 20 Solid-state image sensor 21 Light-receiving surface 22 Electrode pad 30 Conductive adhesive 31 Resin 32 Printing board 33 Recess

Claims (8)

In a solid-state imaging device comprising a rectangular chip-shaped solid-state imaging device and a sealing package for hermetically sealing the solid-state imaging device,
The sealed package includes an upper surface including a light receiving surface of the solid-state imaging device, a package body formed in a concave shape so as to surround each side surface thereof, and is fixed to the package body, and is electrically connected to an electrode pad of the solid-state imaging device. Connected to the package main body, and a heat radiating plate fixed to the package body and abutting on a part of the upper surface of the solid-state image sensor excluding the light-receiving surface, and at least the solid-state image sensor excluding the light-receiving surface A solid-state image pickup device, wherein the solid-state image pickup element is hermetically sealed by filling a resin between the main body and the package body.   The solid-state imaging device according to claim 1, wherein the heat radiating plate is made of metal.   The solid-state imaging device according to claim 1, wherein the heat radiating plate includes a frame-like portion formed so as to abut on the periphery of the light receiving portion.   4. The solid-state imaging device according to claim 1, wherein when the lead is bonded to the mounting substrate, the heat dissipation plate contacts the mounting substrate and emits heat. 5.   5. The solid-state imaging device according to claim 1, wherein a concave portion is provided on a surface of the heat radiating plate or the package main body that is in contact with the resin.   The solid-state imaging device according to claim 1, wherein the resin covers a back surface of the solid-state imaging element.   The solid-state imaging device according to claim 6, wherein a printing plate on which predetermined information is printed is attached to a surface of the resin that covers a back surface of the solid-state imaging element.   8. The solid-state image pickup device according to claim 1, wherein the solid-state image pickup element is a CCD image sensor, and the heat radiating plate is in contact with an output amplifier.

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