JP2006345196A - Holding structure for solid-state imaging element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently radiate heat from a solid-state imaging element package. <P>SOLUTION: The solid-state imaging element 22 comprises a solid-state imaging element chip 29, a frame member 32, and a cover glass 33. A wiring board 34 is fixed to the reverse side of the frame member 32. The frame member 32 has a back opening 41 and the wiring board 34 has an opening 49 to expose the back 30b of a chip substrate 30. The solid-state imaging element package 22 is fixed to a frame 26 by making an abutting surface 26b abut against the back 30b through the back opening 41 and opening 49. A fitting surface 26a for a lens barrel 21 and the abutting surface 26b are formed nearly in parallel and the top surface 30a of the chip substrate 30 where a solid-state imaging element is formed and the optical axis L of a taking lens 20 are nearly perpendicular to each other. Excellent picture quality can, therefore, be obtained. Further, heat from the solid-state imaging chip 29 is conducted to the entire frame 26 through the abutting surface 26b, so the heat radiation is efficiently carried out. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a holding structure for a solid-state image pickup device package containing a solid-state image pickup device chip.

  Digital cameras and video cameras are widely used as electronic devices in which a solid-state imaging device package in which a solid-state imaging device chip such as a CCD or CMOS sensor is housed in ceramics or the like is incorporated. In addition, a solid-state imaging device package and a memory are incorporated into a personal computer, a mobile phone, an electronic notebook, and the like to add a photographing function.

When imaging is performed with an electronic device including a solid-state imaging device package, the temperature of a solid-state imaging device chip, a driving circuit for the solid-state imaging device chip, and the like rise. This is due to heat generation that occurs when charges accumulated in a large number of light receiving elements provided in the solid-state imaging element chip are transferred through a transfer path, and the temperature rises in proportion to the imaging time. Therefore, in Patent Document 1, a heat dissipation member is provided on the lower surface of the semiconductor element mounted on the hollow resin package via an insulating layer. By exposing the lower surface of the heat dissipation member from the hollow resin package, The heat is dissipated. In the semiconductor device disclosed in Patent Document 2, the mounting land on which the packaged CCD element chip is mounted is exposed through a window formed in the base frame, and heat from the CCD element chip is transmitted through the mounting land. Heat is radiated from the window.
JP 2000-158226 A JP 2000-223603 A

  However, in recent years, the number of pixels of a solid-state image sensor has been increased, and the charge accumulated in the solid-state image sensor is also read at a high speed with the increase in the number of pixels, so that the amount of heat generated from the solid-state image sensor chip is large. . Therefore, it is difficult to sufficiently dissipate the heat from the solid-state imaging device chip only by the portion where the heat dissipation member is exposed from the hollow resin package as in Patent Document 1. Further, in Patent Document 2, heat is radiated from a rectangular window portion formed on the frame base, but since the thermal conductivity of air is poor, warm air stagnates in the window portion (inside the opening). In order to radiate heat, it is necessary to provide a fan that convects the air in the window portion.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a solid-state image sensor package holding structure that efficiently dissipates heat from the solid-state image sensor chip.

  The solid-state imaging device package holding structure of the present invention is a holding structure for holding a solid-state imaging device package containing a solid-state imaging device chip on which a plurality of light receiving elements are formed. The solid-state imaging device package includes the solid-state imaging device package. A first opening for exposing the back surface of the element chip is formed, the solid-state imaging device package is held by a holding member that has thermal conductivity and at least a part of which contacts the back surface through the first opening. It is characterized by this. Furthermore, it is preferable to apply a heat-dissipating grease to the contact surface or to sandwich a heat-dissipating sheet.

  In addition, the wiring board is fixed to the solid-state imaging device package on the back side, has an electrode electrically connected to the solid-state imaging device chip, and has a wiring board formed with a second opening that exposes the back surface, The holding member may be brought into contact with the back surface through the second opening to fix the holding member and the wiring board. Also. The holding member is preferably provided with an attachment surface to which the lens barrel is attached, and the abutment surface of the holding member abutted on the back surface and the attachment surface are substantially parallel to each other. Moreover, it is preferable that the holding member is provided with a radiation fin at a position different from the contact surface and the mounting surface.

  According to the present invention, the solid-state imaging device package is formed with the first opening that exposes the back surface of the solid-state imaging device chip, has thermal conductivity, and holds at least partly in contact with the back surface through the first opening. Since the solid-state image sensor package is held by the member, the heat from the solid-state image sensor chip is efficiently radiated. Therefore, deterioration of the performance of the solid-state image sensor chip due to heat can be prevented.

  In addition, a wiring board is provided that is fixed to the solid-state imaging device package on the back side, has an electrode that is electrically connected to the solid-state imaging device chip, has a second opening that exposes the back side, and is held through the second opening. Since the member is brought into contact with the back surface and the holding member and the wiring board are fixed, the contact surface is securely brought into contact with the back surface of the solid-state image sensor chip, and the solid-state image sensor package is firmly fixed. Will be better. In addition, a good captured image can be obtained.

  In addition, since the mounting surface and the contact surface to be attached to the lens barrel are formed substantially in parallel, the solid-state imaging device package is arranged so that the light receiving element is perpendicular to the optical axis of the photographing lens held by the lens barrel. Since it is held, good image quality can be obtained by photographing. Moreover, since the heat radiating fin is provided on the holding member, heat can be radiated more efficiently.

  FIG. 1 is an external perspective view showing a configuration of a mobile phone using the solid-state imaging device package holding structure of the present invention. The mobile phone 2 includes a receiving unit 5, a transmitting unit 6, and a camera unit 8 incorporated in the receiving unit 5 that are foldably connected by a hinge unit 4. A transparent protective plate 10 and a telescopic antenna 11 for protecting the imaging lens 20 (see FIG. 2) are provided on the outer surface of the receiver 5.

  A liquid crystal display (LCD) panel on which various information related to the telephone such as an address book and a telephone number, an image taken by the camera unit 8, and the like and a receiving speaker are incorporated on the inner surface of the receiving unit 5. . On the inner surface of the transmitter 6, in addition to the transmitter microphone 12, there is an operation unit 13 including a dial button and various setting buttons for performing dial operation during transmission, a shutter button and a zoom button operated during photographing, and the like. Is provided. When a memory card (not shown) is loaded in the card slot 15 provided on the side surface of the transmitter section 6, an image photographed by the camera section 8 can be stored in the memory card as image data.

  As shown in FIG. 2, the camera unit 8 includes a lens barrel 21 that holds an imaging lens 20, a solid-state imaging device package 22, and the like. An opening 25 for photographing is formed in the exterior cover 24 of the receiver 5, and one end 21 a of the lens barrel 21 is exposed from the exterior cover 24 in this opening 25. The other end 21b of the lens barrel 21 has a flange shape, and is fixed to a mounting surface 26a of a frame 26 (holding member) constituting a part of a device main body of the cellular phone 2 described later with a screw 27. Yes. The imaging lens 20 is held by a holding unit 28 provided in the lens barrel 21, and a protective plate 10 is provided on the front surface of the imaging lens 20.

  As shown in FIGS. 3 and 4, the solid-state image sensor package 22 includes a solid-state image sensor chip 29, a frame member 32, and a cover glass 33.

The solid-state image sensor chip 29 includes a rectangular chip substrate 30, a solid-state image sensor 31 formed on the chip substrate 30, and a plurality of electrodes 37. This solid-state image sensor chip 29 is
A large number of solid-state imaging elements 31 and electrodes 37 are formed on a chip wafer, and the wafer is diced for each solid-state imaging element 31. The solid-state imaging device 31 is a CCD image sensor including, for example, a plurality of light receiving elements 31a arranged in a matrix shape and charge coupled elements that transport charges accumulated in the light receiving elements 31a in the horizontal and vertical directions. An RGB color film, a microlens, or the like is laminated on the element 31a. Furthermore, the electrode 37 (bonding pad) is formed in the vicinity of the edge of the chip substrate 30, and the electrode 37 is connected to the solid-state imaging device 31 via a wiring layer (not shown) formed inside the chip substrate 30. ing. The plurality of electrodes 37 perform input / output of electric signals with a wiring board 34 described later.

  The frame member 32 is made of ceramic and has a frame shape in which the front opening 40 and the rear opening 41 (first opening) communicate with each other. Inside the frame member 32, a first inner bottom surface 42 is provided to fix the peripheral edge portion of the back surface 30b (see FIG. 3) of the chip substrate 30 with an adhesive. Furthermore, a second inner bottom surface 43 is provided on the inner surface of the frame member 32 outside the first inner bottom surface 42. The second inner bottom surface 43 has a plurality of through holes (not shown) penetrating through the outer surface 32a. A conductive lead frame 45 made of a copper alloy or the like is inserted into the through hole. One end of the lead frame 45 is arranged and exposed on the second inner bottom surface 43, and the lead frame 45 protruding from the outer surface 32a of the frame member 32 is bent downward along the outer surface 32a, The other end of the frame 45 is substantially at the same position as the lower surface of the frame member 32. Thus, the lead frame 45 is substantially L-shaped.

  As shown in FIG. 3, the peripheral portion of the back surface 30 b of the chip substrate 30 is fixed to the first inner bottom surface 42 with an adhesive. Each lead frame 45 is connected by a bonding wire 47 made of a fine metal wire such as gold. At this time, the back surface 30 b of the chip substrate 30 is exposed from the back surface opening 41 of the frame member 32.

  The cover glass 33 is a translucent member formed of a glass material. A cover glass 33 is disposed on the upper surface of the frame member 32 so as to face the solid-state imaging element 31 formed on the surface of the chip substrate 30 and cover the front opening 40, and the peripheral portion of the cover glass 33 is formed of a frame member. The upper surface of 32 is fixed with an adhesive. Therefore, since the front opening 40 of the frame member 32 is closed by the cover glass 33 and the back opening 41 is closed by the back surface 30b of the chip substrate 30, dust and moisture may enter the inside of the frame member 32. It is prevented. A transparent resin member may be used instead of the cover glass 33.

  A wiring board 34 is fixed to the lower part of the solid-state imaging device package 22. An opening 49 (second opening) having substantially the same shape as the back opening 41 of the frame member 32 is formed at the center of the wiring board 34. The frame member 32 is fixed to the wiring board 34 with the back surface opening 41 and the opening 49 aligned. As a result, the back surface 30 b of the chip substrate 30 is exposed from below the wiring substrate 34 through the back surface opening 41 and the opening 49. A foot pattern 50 as an electrode is formed on the surface of the wiring board 34 and at a position corresponding to the other end of the lead frame 45 provided on the frame member 32, and other portions are insulated. . The foot pattern 50 and the lead frame 45 are electrically connected by solder. As a result, the solid-state imaging element 31 and the wiring board 34 are electrically connected, and the wiring board 34 is fixed to the solid-state imaging element package 22. Although not shown, the foot pattern 50 is electrically connected to a signal processing unit via a flexible cable or the like, and this signal processing unit receives an image information signal (electric signal) sent from the solid-state imaging device 31. Process.

  The solid-state image pickup device package 22 configured as described above is fixed to the frame 26 constituting a part of the mobile phone 2 by the receiver 5. The frame 26 as a holding member is made of, for example, aluminum. The frame 26 is formed with a mounting surface 26a for attaching the lens barrel 21 described above, a contact surface 26b for contacting the back surface 30b of the chip substrate 30, and a recess 26c. The attachment surface 26a and the contact surface 26b are formed to be substantially parallel, and a recess 26c is formed between the attachment surface 26a and the contact surface 26b. An insulating heat dissipation sheet 51 is provided between the contact surface 26b and the back surface 30b of the chip substrate 30, and the frame 26 and the solid-state imaging device chip 29 are insulated. Although aluminum is used for the frame 26, the present invention is not limited to this, and a metal having high thermal conductivity may be used. Moreover, although the heat radiating sheet 51 is provided between the contact surface 26b and the back surface 30b, instead of this, heat radiating grease may be applied or an alumite treatment may be performed on the contact surface 26b.

  When the solid-state image pickup device package 22 is attached to the frame 26, the contact surface 34 a passes through the back opening 41 formed in the frame member 34 and the opening 49 formed in the wiring substrate 34, and passes through the back surface 30 b of the chip substrate 30. Positioning is performed so that the optical axis L (see FIG. 2) of the photographing lens 20 coincides with the center of the solid-state imaging device 31 by bringing the contact surface 34a into contact. At this time, a part of the frame member 32 disposed below the attachment surface 26a and the contact surface 26b and the wiring board 34 enter the recess 26c. Then, the solid-state imaging device package 22 is fixed to the frame 26 by fixing the recess 26 c and the lower surface of the wiring board 34 with the UV curable adhesive 52.

  Next, the operation of the above embodiment will be described. When photographing is performed by the mobile phone 2, the solid-state image sensor chip 29 generates heat. The heat of the solid-state imaging device chip 29 is conducted to the entire frame 26 from the contact surface 26 b that is in contact with the back surface 30 b of the chip substrate 30 via the heat dissipation sheet 51. As a result, the heat conducted to the frame 26 is dissipated from the entire frame 26 into the air, and is also conducted to the device body such as the exterior cover 24 connected to the frame 26, so that heat is efficiently dissipated. Is called. Therefore, it is possible to prevent the performance of the solid-state imaging device chip 29 from being deteriorated by heat.

  Further, since the frame 26 is formed with the mounting surface 26a and the contact surface 26b so as to be substantially parallel, the surface 30a on which the solid-state imaging device 31 is provided with respect to the optical axis L of the imaging lens 20 is substantially vertical. Become. Thereby, it is possible to prevent the photographed image quality from being deteriorated and to obtain a good photographed image.

  In the above embodiment, the frame member 32 is directly fixed to the wiring board 34. Instead, as shown in FIG. 5, the frame member 32 and the wiring board 34 are fixed by being separated by a lead frame 55. May be. In addition, the same code | symbol is attached | subjected to the same structural member as the said embodiment, and the overlapping description is abbreviate | omitted.

  One end of the lead frame 55 provided in the solid-state image pickup device package 54 is exposed and fixed to the second inner bottom surface 43 of the frame member 32, and is connected to the electrode 37 of the solid-state image pickup device chip 29 by the bonding wire 47. Yes. The other end of the lead frame 55 protrudes from a through hole formed in the frame member 32, and the lead frame 55 is bent along the outer surface 32 a to the frame member 32. Thus, the other end of the lead frame 55 is disposed below the lower surface of the frame member 32. The other end of the lead frame 55 is connected to the foot pattern 50 of the wiring board 34 disposed below the frame member 32 by solder. Thereby, the lead frame 55 fixes the wiring board 34 to the solid-state imaging device package 22 and electrically connects the solid-state imaging device 31 and the wiring board 34.

  When the solid-state imaging device package 54 is fixed to the frame 26, the contact surface 26 b is passed through the back opening 41 of the frame member 32 and the opening 49 of the wiring substrate 34, and the back surface 30 b of the chip substrate 30 is interposed via the heat dissipation sheet 51. Then, the lower surface of the wiring board 34 and the recess 26 c of the frame 36 are fixed by the UV curable adhesive 52. Thereby, the solid-state imaging device package 54 is positioned in the frame 26 and fixed in a state where the contact surface 26b is securely in contact with the back surface 30b. Although the solid-state image pickup device package 54 of the type in which the frame member 32 and the wiring board 34 are separated and fixed by the lead frame 55 is used, instead of this, an LCC type solid-state image pickup device package that does not use the lead frame 55 is used. In this case, it is preferable to fix the wiring board 34 directly to the frame member.

  Further, the frame 26 for fixing the lens barrel 21 and the solid-state imaging device package 22 may be replaced with a shape with higher heat dissipation efficiency. In this case, as shown in FIG. 6, the heat dissipating fins 61 including a plurality of concave and convex portions are formed on the surface opposite to the mounting surface 26 a and the contact surface 26 b of the frame 60. With such a configuration, when heat from the solid-state imaging element chip 29 is conducted from the contact surface 26 b to the entire frame 60, heat radiation is efficiently performed by the radiation fins 61. The heat dissipating fins 61 may be provided anywhere as long as the positions are different from the attachment surface 26a and the contact surface 26b.

  Moreover, in the said embodiment, although the frame member 32 was formed with ceramic, it is not restricted to this, You may make it form with resin, such as a plastics. Further, although the lens barrel 21 is fixed to the frame 26 with the screws 27, it may be fixed with an adhesive.

  Further, in each of the above embodiments, in order to expose the back surface 30 b of the chip substrate 30, the back opening 41 is provided in the frame member 32 and the opening 46 is provided in the wiring board 34, but the shape of the back opening 41 and the opening 49 The number of openings is not limited to this, and openings having a lattice shape or a circular shape may be formed, and a plurality of openings may be provided. In such a case, it is preferable to appropriately change the shape and number of the contact surfaces 26b of the frame 26 in accordance with the shape and number of openings formed in the frame member 32.

  In the present embodiment, the solid-state imaging device package 22 is attached to the mobile phone 2, but the present invention is not limited to this and may be attached to an electronic device such as a digital camera, a personal computer, an electronic notebook, or a PDA.

1 is an external perspective view of a mobile phone embodying the present invention. It is sectional drawing which shows the structure of a camera part. It is sectional drawing which shows the structure of the attachment part vicinity of a solid-state image sensor package. It is a disassembled perspective view which shows the structure of a solid-state image sensor package. It is sectional drawing explaining attachment of the solid-state image sensor package with which the wiring board was spaced apart and fixed. It is sectional drawing explaining embodiment which formed the radiation fin in the flame | frame.

Explanation of symbols

2 Cellular phone 20 Imaging lens 21 Lens barrel 22 Solid imaging device package 26 Frame 26a Mounting surface 26b Abutting surface 29 Solid imaging device chip 31 Solid imaging device 31a Light receiving device 32 Frame member 33 Cover glass 34 Wiring board 41 Rear opening 49 Opening 50 Foot pattern 61 Radiation fin

Claims (4)

In a holding structure for holding a solid-state imaging device package containing a solid-state imaging device chip having a plurality of light receiving elements formed on the surface,
The solid-state imaging device package has a first opening that exposes the back surface of the solid-state imaging device chip,
A structure for holding a solid-state image pickup device package, wherein the solid-state image pickup device package is held by a holding member having thermal conductivity and at least a part of which is in contact with the back surface through the first opening. A wiring board that is fixed to the solid-state image sensor package on the back surface side, has an electrode that is electrically connected to the solid-state image sensor chip, and has a second opening that exposes the back surface;
2. The solid-state imaging device package holding structure according to claim 1, wherein the holding member is brought into contact with the back surface through the second opening to fix the holding member and the wiring board. The holding member has a mounting surface on which a lens barrel is attached,
3. The solid-state image pickup device holding structure according to claim 1, wherein an abutting surface of the holding member abutted on the back surface and the mounting surface are formed to be substantially parallel. The solid-state image pickup device package holding structure according to any one of claims 1 to 3, wherein the holding member is provided with heat radiation fins at positions different from the contact surface and the mounting surface.

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