JP2010263004A - Solid-state image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that a light reception defect, etc., occurs by dew condensation in a light reception area when temperature rapidly changes in a use environment concerning a solid-state image pickup device which forms a radiator plate in a package in order to radiate generated heat from a solid-state image pickup element to an external part. <P>SOLUTION: The solid-state image pickup device includes: a base body; and the radiator plate, and stores the solid-state image pickup element in an internal space. The radiator plate is not exposed to the internal space. A heat resistance on the inner bottom surface of a region immediately under the light non-reception area of the solid-state image pickup element is made to be smaller than a heat resistance on the inner bottom surface of a region immediately under the light reception area. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solid-state imaging device having an internal space hermetically sealed inside, which is suitable for application to a line sensor, a digital camera, and the like, and a solid-state imaging device mounted on an internal bottom surface in the internal space. .

  Conventionally, as a solid-state image pickup device equipped with a solid-state image pickup device such as a CCD or CMOS used for a digital camera or a mobile phone, a structure in which the solid-state image pickup device is mounted on an inner bottom surface in an airtightly sealed internal space is often used. It is done. This structure is obtained by mounting a solid-state imaging device on a package and connecting the light-transmitting member to the package with a sealing resin after connection such as wire bonding. When the heat generated during the operation of the solid-state imaging device is trapped in the hermetically sealed internal space, the temperature of the solid-state imaging device itself rises, and image defects such as so-called white spot scratches occur. End up. In particular, in recent years, the amount of heat generation has been increasing due to the rapid progress in increasing the number of pixels and the speed of the solid-state imaging device itself, and the temperature rise of the device itself has become remarkable. Therefore, the necessity of the heat radiating means for suppressing heat_generation | fever arises. The heat radiation of the solid-state image sensor is also somewhat dissipated from the connection electrodes such as wires and leads connected to the electrode pads formed on the surface of the solid-state image sensor, but the connection electrodes need to be formed thinly at a rate limited by the electrode pad size. Therefore, the thermal resistance is high and hardly contributes to heat dissipation.

  Further, if a heat sink is placed on the surface side so as to dissipate heat from the surface side of the solid-state imaging device at a portion other than the electrode pad, the placement space becomes large and the device itself becomes large. Moreover, since an insulation process is required to prevent contact with a circuit formed on the surface of the solid-state imaging device, it is not practically used.

  Therefore, it is necessary to dissipate heat from the back side of the solid-state imaging device. Japanese Patent Application Laid-Open No. 2004-146530 and Japanese Patent Application Laid-Open No. 5-190585 disclose means for dissipating heat from the back side of the solid-state image sensor by providing a heat sink made of metal on the back side of the solid-state image sensor. ing.

JP 2004-146530 A JP-A-5-190585

  However, the configuration in which the heat sink is formed on the back side of the solid-state imaging device has the following problems.

  When the heat radiating plate inside the package is uniformly arranged just under the mounting area of the solid-state image sensor as in Patent Document 1, the entire solid-state image sensor is uniformly cooled, so that the use environment is drastically reduced. Due to the change, condensation occurs in the light receiving area of the solid-state imaging device.

  The airtightly sealed internal space inside the solid-state imaging device inevitably contains moisture present in the air in the atmosphere at the time of production, and moisture that passes through the sealing resin itself over time There is also moisture that enters from the interface of various members. When the internal space contains such moisture, when the temperature of the environment in which the solid-state imaging device is used decreases rapidly, the air in the internal space is cooled, and when the amount of water vapor in the internal space exceeds the saturated water vapor amount, Condensation will occur in the space.

  In particular, when a heat sink is used for cooling a solid-state image sensor in a solid-state image pickup device, the heat resistance value of the heat sink is often lower than the heat resistance value of a package or a translucent member. It will be cooled first. As a result, when the heat sink is uniformly disposed below the solid-state image sensor, the solid-state image sensor disposed on the upper surface of the heat sink is also uniformly cooled to cause condensation in the light receiving area of the solid-state image sensor. Will occur. When condensation occurs in the light receiving area of the solid-state image sensor, there is a problem that the light entering the light receiving area is blocked or the amount of light entering the light receiving area is reduced, resulting in poor light reception and image blurring. there were.

  In addition, in the case of Patent Document 2, in addition to the heat radiation plate disposed immediately below the region corresponding to the light receiving area of the solid-state image sensor, as in Patent Document 1, the solid-state image sensor on the inner bottom surface of the package. A heat sink is formed so as to be exposed in the non-mounting area.

  In this case, since the exposed part of the heat sink is cooled earlier than the light receiving area, it is possible to prevent condensation in the light receiving area. However, if the exposed part of the heat sink exists in the package, the light rays that have entered from the translucent member are reflected by the surface of the heat sink exposed on the inner bottom surface of the package and enter the light receiving area of the solid-state image sensor. This is a configuration that causes another problem of causing problems such as flare.

  The present invention has been made in view of the above problems, and provides a structure that reduces the condensation on the light receiving area without causing a flare problem while maintaining the heat dissipation of the solid-state imaging device.

  The above-described problem of the present invention is a solid-state imaging device comprising a base and a heat sink, and having a recess having a bottom surface inside, and mounted on the inner bottom surface of the recess and having a light receiving area and a non-light receiving area on the surface. In a solid-state imaging device including an element and a light-transmitting member that forms an internal space hermetically sealed inside the concave portion together with the concave portion, the heat dissipation plate is not exposed to the internal space. And a solid-state imaging device, wherein the thermal resistance of the inner bottom surface of the region immediately below the non-light-receiving area is configured to be smaller than the thermal resistance of the inner bottom surface of the region immediately below the light-receiving area. Solved.

  According to the present invention, heat dissipation can be maintained, and at the same time, the non-light-receiving area can be cooled more quickly than the light-receiving area, so that condensation on the light-receiving area can be reduced. Further, since the heat radiating plate is a heat radiating plate that is not exposed to the hermetically sealed internal space of the solid-state imaging device, there is no exposed portion of the heat radiating plate viewed from the light beam, and the problem of flare does not occur.

It is sectional drawing and the top view of the solid-state imaging device of 1st embodiment of this invention. It is a figure explaining the name of a package. It is a partial enlarged view of 1st embodiment of this invention. It is sectional drawing of the solid-state imaging device of the 2nd embodiment of this invention. It is sectional drawing of the solid-state imaging device of 3rd embodiment of this invention. It is sectional drawing of the solid-state imaging device of 4th embodiment of this invention. It is sectional drawing of the solid-state imaging device of 5th embodiment of this invention.

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

(First embodiment)
A first embodiment of the present invention will be described with reference to the drawings.

  1A and 1B are a cross-sectional view of the solid-state imaging device showing the first embodiment of the present invention and a top view of the package for showing the position of the exposed portion of the heat sink, respectively. These are the figures which show the definition of the internal bottom face of a package, an external bottom face, and an external side surface.

  In the figure, 101 is a substrate, 102 is a solid-state image sensor, 103 is a light-receiving area formed on the solid-state image sensor, 104 is a non-light-receiving area, 105 is a translucent member, and 106 is a heat sink. A package 112 includes a base 101 and a heat sink 106 and has a recess having a bottom surface inside.

  Reference numeral 107 denotes an adhesive that bonds the solid-state imaging device 102 and the package 112. Reference numeral 108 denotes a wire for connecting the solid-state imaging device 102 and the inner lead 111, and 109 denotes a sealing resin for bonding the package 112 and the translucent member 105. The solid-state imaging device 102 is mounted on the inner bottom surface in the inner space hermetically sealed by the package 112, the translucent member 105, and the sealing resin 109.

  Here, the light receiving area 103 is an area on the surface of the solid-state imaging device where a photodiode contributing to an image is formed. On the other hand, the non-light receiving area 104 is a region on the surface of the solid-state imaging device other than the light receiving area, and is a region where so-called peripheral circuits such as an amplifier circuit (amplifier), a shift register, and a timing generator are formed. In the solid-state imaging device of the present invention, a portion where the heat radiating plate 106 contacts the inner bottom surface of the package 112 without contacting the solid-state imaging element via the base (hereinafter, such a portion is referred to as a contact portion in the present invention) 110. Is forming. The heat radiating plate 106 is formed so that the contact portion exists only in a region immediately below the non-light-receiving area 104 of the solid-state imaging device in the mounting region of the solid-state imaging device 103. That is, the heat sink is not exposed to the internal space, and the thermal resistance of the inner bottom surface of the region immediately below the non-light receiving area is smaller than the thermal resistance of the inner bottom surface of the region immediately below the light receiving area. Is a feature. This will be described with reference to FIG.

  FIG. 3 shows an enlarged view of portion A in FIG. 3, the same members as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted. In FIG. 3, the heat radiating plate 106 on the inner bottom surface of the package 112 is formed so that the contact portion 110 exists only in a region immediately below the non-light-receiving area 104 in the mounting region of the solid-state imaging device 102. In addition, the area immediately below the light receiving area has no contact portion.

  First, the heat sink has a structure in which the contact portion 110 is provided on the inner bottom surface of the package. As a result, the heat of the solid-state imaging device can be efficiently radiated from the contact portion. In addition, the contact portion is formed not only on the inner bottom surface but also in the region immediately below the non-light receiving area in the present invention. That is, by forming a contact portion on the inner bottom surface of the package in a region immediately below the non-light-receiving area, it is possible to efficiently cool the peripheral circuit portion that is the main heat source of the solid-state imaging device.

  On the other hand, the contact part is formed only in the region immediately below the non-light receiving area, so that the non-light receiving area is cooled earlier than the light receiving area of the solid-state image sensor when the temperature of the environment in which the solid-state imaging device is used decreases. can do. As a result, it is possible to reduce / prevent the occurrence of dew condensation caused by the temperature drop in the light receiving area of the solid-state imaging device.

  Furthermore, since the contact portion is formed only in the region immediately below the non-light receiving area, the heat radiating plate is completely hidden by the solid-state imaging device. Therefore, when viewed from the incident light, the exposed portion of the heat sink does not exist, and the problem of flare does not occur.

  In the present embodiment, the contact portion 110 has a Lono character shape when viewed from above so as to be present in the entire region immediately below the non-light-receiving area of the solid-state imaging device. However, the shape is not limited to the Ronoji shape, and it may be provided in a part of the region immediately below the non-light receiving area.

  In particular, when an amplifier circuit (amplifier) is provided in a partial region of the non-light-receiving area, it is preferable to form the contact portion so as to include a region immediately below the amplifier circuit. That is, by forming the contact portion so as to include the region immediately below the amplifier circuit, it is possible to efficiently dissipate the portion that is the main heat source in the solid-state imaging device.

  The material of the heat sink is preferably a metal material having high thermal conductivity such as copper, aluminum, iron, SUS, or the like. The heat radiating plate can be subjected to a surface treatment entirely or partially as required, and may be plated with, for example, gold, silver, nickel, or solder.

  As a material of the substrate 101, a known material such as ceramic or resin can be used, and for the translucent member 105, known glass, crystal, transparent resin or the like can be used. Moreover, about a translucent member, you may form various coatings, such as an antireflection coat and IR coat, on the surface and back surface of a suitable translucent member as needed.

  The adhesive 107 is a part of the heat dissipation path in the present invention, and is an important member that affects the heat dissipation. However, as long as the adhesive 107 is formed with a known thickness of about 1 to 100 μm, the present invention is nothing. It does not impede the effect. Of course, it is most preferable when the adhesive 107 is not provided.

(Second embodiment)
A second embodiment of the present invention will be described with reference to the drawings. In addition, about the part which overlaps with 1st embodiment, since it is the same as that of 1st embodiment, description is omitted.

  FIG. 4 is a cross-sectional view of a solid-state imaging device showing a second embodiment of the present invention. In the figure, 401 is a substrate, 402 is a solid-state image sensor, 403 is a light-receiving area formed on the solid-state image sensor, 404 is a non-light-receiving area, 405 is a translucent member, and 406 is a heat sink. Reference numeral 412 denotes a package including a base body 401 and a heat radiating plate 406. Reference numeral 407 denotes an adhesive that bonds the solid-state imaging element 402 and the package 412. Reference numeral 408 denotes a wire for connecting the solid-state imaging element 402 and an inner lead (not shown), and 409 denotes a sealing resin for bonding the package 412 and the translucent member 405. The solid-state imaging element 402 is mounted on the inner bottom surface in the inner space hermetically sealed by the package 412, the translucent member 405, and the sealing resin 409. The difference from the first embodiment is that the heat radiating plate 406 of the package is formed so as to be exposed also on the external side surface. The definition of the external side is as shown in FIG.

  In the above configuration, the heat radiating plate is formed so as to be exposed to both the hermetically sealed internal space of the solid-state imaging device and the outside of the solid-state imaging device.

  Since the heat radiation plate is exposed on the outer side surface, it can be directly connected to an external cooling means such as a fin, and the heat radiation efficiency can be further improved. In addition, the non-light receiving area can be more efficiently cooled against condensation, which is a preferable configuration.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG. In addition, about the part which overlaps with 1st embodiment, since it is the same as that of 1st embodiment, description is omitted.

  FIG. 5 shows a cross-sectional view of a solid-state imaging device showing a third embodiment of the present invention. In the figure, reference numeral 501 denotes a substrate, 502 a solid-state image sensor, 503 a light-receiving area formed on the solid-state image sensor, 504 a non-light-receiving area, 505 a translucent member, and 506 a heat sink. Reference numeral 512 denotes a package including a base body 501 and a heat sink 506. Reference numeral 507 denotes an adhesive that adheres the solid-state imaging element 502 and the package 512. Reference numeral 508 denotes a wire for connecting the solid-state imaging element 502 and an inner lead (not shown), and 509 denotes a sealing resin for bonding the package 512 and the translucent member 505. The solid-state imaging element 502 is mounted on the inner bottom surface in the inner space hermetically sealed by the package 512, the translucent member 505, and the sealing resin 509.

  The difference from the first embodiment is that the heat radiating plate 506 is formed so as to be exposed to the external space on the outer bottom surface of the package.

  Since the heat radiating plate is exposed to the external space on the outer bottom surface, it can be directly connected to external cooling means such as fins, and the heat radiation efficiency can be further improved. In addition, the non-light receiving area can be more efficiently cooled against condensation, which is a preferable configuration.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG. In addition, about the part which overlaps with 1st embodiment, since it is the same as that of 1st embodiment, description is omitted.

  FIG. 6 shows a cross-sectional view of a solid-state imaging device showing a fourth embodiment of the present invention. In the figure, reference numeral 601 denotes a substrate, 602 a solid-state image sensor, 603 a light-receiving area formed on the solid-state image sensor, 604 a non-light-receiving area, 605 a translucent member, and 606 a heat sink. Reference numeral 612 denotes a package including a base 601 and a heat sink 606. Reference numeral 607 denotes an adhesive that bonds the solid-state image sensor 602 and the package 612. Reference numeral 608 denotes a wire for connecting the solid-state image sensor 602 and an inner lead (not shown), and 609 denotes a sealing resin for bonding the package 612 and the translucent member 605. The solid-state imaging device 602 is mounted on the inner bottom surface in the inner space hermetically sealed by the package 612, the translucent member 605, and the sealing resin 609.

  The difference from the first embodiment is that the heat radiating plate 606 is formed so as to be exposed to the external space on both the outer bottom surface and the outer side surface of the package.

  Since the heat radiating plate is exposed on the outer bottom surface and the outer side surface, it can be directly connected to an external cooling means such as a fin, and the heat radiation efficiency can be further improved. In addition, the non-light receiving area can be more efficiently cooled against condensation, which is a preferable configuration.

(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to FIG. Note that a description of the same parts as those in the above embodiment is omitted.

  FIG. 7 shows a cross-sectional view of a solid-state imaging device showing a fifth embodiment of the present invention. In the figure, reference numeral 701 denotes a substrate, 702 a solid-state image sensor, 703 a light-receiving area formed on the solid-state image sensor, 704 a non-light-receiving area, 705 a translucent member, and 706 a heat sink. Reference numeral 712 denotes a package including a base body 701 and a heat sink 706. Reference numeral 707 denotes an adhesive that bonds the solid-state imaging device 702 and the package 712. Reference numeral 708 denotes a wire for connecting the solid-state imaging device 702 and an inner lead (not shown), and 709 denotes a sealing resin for bonding the package 712 and the translucent member 705. The solid-state imaging device 702 is mounted on the inner bottom surface in the inner space hermetically sealed by the package 712, the translucent member 705, and the sealing resin 709.

  In FIG. 7, the heat radiating plate integrally formed with the base body in the package is not disposed at all in the region immediately below the light receiving area of the solid-state imaging device. The region directly under the light receiving area of the package is composed only of the substrate.

  In this way, the area directly under the light receiving area of the package is composed only of the substrate, so that the thermal resistance value of the package immediately below the non-light receiving area is compared with the thermal resistance value of the package immediately below the light receiving area. In this case, a large difference in thermal resistance value can be formed.

  That is, the thermal resistance value of the package in the region immediately below the non-light-receiving area can be made extremely smaller than the thermal resistance value of the package in the region immediately below the light-receiving area.

  As a result, when the temperature of the solid-state imaging device suddenly drops, the non-light-receiving area can be cooled more efficiently than the light-receiving area, thus preventing condensation in the light-receiving area and preventing condensation in the light-receiving area. Is possible.

  In the first embodiment to the fifth embodiment described above, an example in which the heat sink is in contact with the solid-state imaging device without a base in the region immediately below the non-light-receiving area has been described. The present invention is not limited to such an embodiment. For example, in any region, the heat sink is in contact with the solid-state imaging device through the base, but the thickness of the base between the element and the heat sink in the region immediately below the non-light receiving area is equal to that in the region immediately below the light receiving area. You may comprise so that it may become thinner than it. The present invention has all such modifications as long as the thermal resistance of the inner bottom surface of the region immediately below the non-light receiving area is smaller than the thermal resistance of the inner bottom surface of the region immediately below the light receiving area. It is included.

DESCRIPTION OF SYMBOLS 101 Base | substrate 102 Solid-state image sensor 103 Light-receiving area 104 Non-light-receiving area 105 Translucent member 106 Heat sink 107 Adhesive 108 Wire 109 Sealing resin 110 The part which a heat sink contacts a solid-state image sensor and a base | substrate (contact part)
111 Inner lead 112 package

Claims (4)

A package comprising a base and a heat sink and having a recess having a bottom surface inside;
A solid-state imaging device mounted on the inner bottom surface of the recess and having a light receiving area and a non-light receiving area on the surface;
In the solid-state imaging device comprising the translucent member that constitutes an internal space hermetically sealed inside the concave portion together with the concave portion,
The heat sink is not exposed to the internal space, and
A solid-state imaging device, wherein a thermal resistance of an inner bottom surface of a region immediately below the non-light receiving area is configured to be smaller than a thermal resistance of an inner bottom surface of the region immediately below the light receiving area.   The heat radiating plate is in contact with the solid-state imaging device only through the base body only at the inner bottom surface of the region immediately below the non-light-receiving area, and through the base member at the inner bottom surface of the region immediately below the light-receiving area. The solid-state imaging device according to claim 1, wherein the solid-state imaging device is in contact with the solid-state imaging device.   2. The solid-state imaging device according to claim 1, wherein the heat radiating plate is provided only in a region immediately below the non-light-receiving area, and the region immediately below the light-receiving area is configured only by a base.   4. The solid-state imaging device according to claim 1, wherein the heat radiating plate is configured to be exposed to an external space on an external bottom surface or an external side surface of the package. 5.