JP2008130738A - Solid-state imaging element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve sealing property and heat dissipation of a solid-state imaging element of a WLCSP type. <P>SOLUTION: An imaging element main body 12 stored in a case 13 is provided with an image sensor chip 16 where a light receiving part 15 is arranged, a spacer 17 fitted onto the image sensor chip 16 so that it surrounds the light receiving part 15 and cover glass 18 which is fitted on the spacer and seals the light receiving part 15. A bonding pad 21 is disposed between the image sensor chip 16 and the spacer 17. Through wiring 22 passing through the image sensor chip 16 and reaching a lower face is installed below the pad. A solder bump 24 is arranged in a position corresponding to a through wiring 22 on a lower face of the image sensor chip 16. The solder bump 24 is electrically connected to the through wiring 29 passing through the case 13 and is connected to an outer side of the lower face. A gap caused in a recess is filled with filling resin 31 and the gap is blocked. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wafer level chip size package (WLCSP) type solid-state imaging device.

  Digital cameras and video cameras using solid-state imaging devices such as CCDs and CMOSs have become widespread. A conventional solid-state imaging device includes an image sensor chip in which a light receiving unit is provided on a silicon chip, a ceramic or plastic case that houses the image sensor chip, and a transparent cover glass that seals the case It consists of. The image sensor chip housed in the case is electrically connected by wire bonding between the electrode pad provided on the chip and the connection terminal of the case, and the external connection terminal of the case is mounted on the mounting substrate. Connected to the circuit.

  Solid-state image sensors are also used in small electronic devices such as mobile phones and endoscope cameras. However, the size of the solid-state image sensor has a large effect on the outline drawing, so it is hoped that the solid-state image sensor will be downsized. It was rare. In order to reduce the size of the solid-state imaging device, a solid-state imaging device using WLCSP has been invented (see, for example, Patent Documents 1 and 2).

WLCSP is a packaging method for performing packaging up to a semiconductor wafer process. A solid-state imaging device manufactured using WLCSP includes, for example, an image sensor chip provided with external connection terminals and a cover glass that is attached to the image sensor chip and seals a light receiving unit. Since it is about the same as a bare chip, it can be significantly reduced in size compared to a case using a case.
JP 2004-031498 A JP 2004-363380 A

  In the conventional solid-state imaging device, the case for housing the chip has a role of maintaining the sealing performance of the light receiving unit. However, since the WLCSP type solid-state imaging device described in Patent Document 1 does not include a case, the sealing performance is slightly impaired, and there is a problem in the moisture-resistant surface.

  The WLCSP type solid-state imaging device described in Patent Document 2 maintains a certain degree of sealing performance by covering the side surface with resin. However, it does not have a case and cannot be said to have sufficient sealing performance. Further, the manufacturing process is complicated, for example, a dicing process is separately incorporated before the sealing process at the wafer level.

  In addition, as the memory capacity increases and the logic functions and integration increases, power consumption increases, and a rise in temperature due to heat generated by the chip is a problem. This is because the solid-state imaging device does not operate normally unless the chip is kept below a certain temperature. In the case of a conventional solid-state imaging device, heat is transferred to the case to reduce the temperature rise of the chip itself. However, in the case of the WLCSP type solid-state imaging device described in Patent Documents 1 and 2, since the case is not provided, there is a problem that heat radiation cannot be performed sufficiently and the temperature becomes high.

  SUMMARY An advantage of some aspects of the invention is to improve the sealing performance and heat dissipation of a WLCSP type solid-state imaging device.

  In order to achieve the above object, a solid-state imaging device according to the present invention includes a chip provided with a light receiving portion on a surface, a spacer provided on the chip so as to surround the light receiving portion, and a light receiving portion provided on the spacer. An image pickup device body including a transparent cover to cover and a first electrical connection portion protruding from the back surface of the chip, and a recess for storing the image pickup device body are formed, and the first of the stored image pickup device is formed in the recess. An insulating case provided with a second electrical connection portion that is electrically connected to the electrical connection portion, and a gap generated in a recess housing the image sensor body is blocked by a resin And

  The case is preferably made of a material having high thermal conductivity such as ceramics.

  According to the solid-state image pickup device of the present invention, the image pickup device body having the light receiving portion is housed in the recess of the case, and the gap generated in the recess is blocked by the resin, thereby improving the sealing performance and heat dissipation. be able to.

  Hereinafter, the solid-state imaging device 11 of the present invention will be described with reference to the drawings. As shown in FIG. 1, the solid-state image sensor 11 includes an image sensor body 12 and a case 13.

  As shown in FIGS. 2A and 2B, the image sensor body 12 is obtained by dividing the image sensor substrate 14 manufactured at the wafer level into a rectangular shape, and a light receiving portion 15 is provided at the center of the upper surface. An image sensor chip 16, a rectangular frame spacer 17 mounted on the image sensor chip 16 so as to surround the light receiving unit 15, and a cover glass 18 mounted on the spacer 17 and sealing the light receiving unit 15. Consists of. However, the image pickup device body may be a WLCSP type, and is not limited to the embodiment (image pickup device body 12) described here.

  The light receiving unit 15 is, for example, a large number of photodiodes arranged in a matrix, and together with a charge coupled device (CCD) that transports charges accumulated in the photodiodes, the image sensor chip 16 is formed by a known semiconductor process. Is provided on the upper surface of the. An RGB color filter and a microlens array 15a are stacked on each photodiode.

  The image sensor chip 16 has a laminated structure, but can be roughly divided into two. The upper layer is a silicon layer 19 provided with a light receiving portion 15, and the lower layer is an insulating layer 20 made of an insulating material. The insulating layer 20 also has an effect of supplementing the strength of the silicon layer 19.

  Between the image sensor chip 16 and the spacer 17, for example, a plurality of bonding pads 21 formed of aluminum and electrically connected to the light receiving unit 15 are provided. Under each bonding pad 21, a through wiring 22 that is electrically connected to the bonding pad 21 and penetrates the image sensor chip 16 to reach the lower surface is provided. An insulating film 23 is provided between the image sensor chip 16 and the through wiring 22 to insulate between the two. A plurality of hemispherical solder bumps (first electrical connection portions) 24 are provided on the lower surface of the image sensor chip 16 at positions corresponding to the through wirings 22.

  The spacer 17 is a rectangular frame in which a rectangular opening 25 is formed in the center, and is bonded to the upper surface of the image sensor chip 16 by an adhesive 26 so as to surround the outer periphery of the light receiving unit 15. The spacer 17 is made of an inorganic material such as silicon. The spacer 17 forms a gap between the light receiving unit 15 and the cover glass 18, thereby preventing the microlens array 15 a from interfering with the cover glass 18.

  The cover glass 18 is bonded to the upper surface of the spacer 17 with an adhesive 27 so as to close the opening 25.

  The case 13 is made of resin, and as shown in FIG. 3, a rectangular recess 28 is formed that is substantially the same size as the image pickup device body 12 or a size that is slightly larger. The image sensor body 12 is housed in the recess 28 from the lower surface side of the image sensor chip 16. At the bottom of the case 13, a metal penetrating wiring (second electrical connection portion) 29 that penetrates the case 13 and connects to the outside of the lower surface is provided at a position corresponding to the solder bump 24 of the image pickup device body 12 to be accommodated. Yes. The through wiring 29 is electrically connected to the solder bump 24 of the image pickup device body 12 housed in the recess 28. A plurality of metal connection terminals 30 are provided on the lower surface of the case 13 at positions corresponding to the through wirings 29.

  As shown in FIG. 1, a filling resin 31 is injected into a gap generated in the recess 28 in which the image pickup device body 12 is housed, and the gap is closed. The filling resin 31 also functions as an adhesive, and fixes the imaging element body 12 to the recess 28. The filling resin 31 may be a room temperature curing type or a thermosetting type. The side surface of the image pickup device body 12 is covered with the filling resin 31, and the sealing performance is improved. In addition, since the image sensor main body 12 is accommodated in the case 13 and the heat generated by the image sensor chip 16 (image sensor main body 12) can move to the case 13, the temperature rise of the image sensor chip 16 itself can be reduced. .

  In the above-described embodiment, the case of the hemispherical solder bump 24 as the external connection terminal provided on the lower surface of the image sensor chip 16 has been described as an example. However, the present invention is not limited to this. An electrically conductive film, an anisotropic conductive paste, or the like may be used. However, the condition is that it protrudes from the lower surface of the image sensor chip 16.

  In the above embodiment, the case 13 is made of resin as an example. However, the case 13 is not limited to this, and may be ceramics or other electrically insulating materials. When the material of the case 13 is ceramic, it is desirable that the through wiring 29 and the connection terminal 30 are, for example, those obtained by plating tungsten (W) with nickel (Ni) and gold (Au). Note that the material of the case 13 may be a substance having high thermal conductivity. If the material of the case 13 is a substance having a high thermal conductivity, the solid-state imaging device 11 is further excellent in heat dissipation.

  Moreover, in the said embodiment, although the case where the penetration wiring 29 connected to the bottom surface outer side from the inner side of the recessed part 28 was provided in the bottom of the case 13 was demonstrated to the example, the penetration wiring 29 is connected to the lower surface outer side. It is not limited to. For example, the case 33 that constitutes the solid-state imaging device 32 shown in FIG. 4 can be considered. At the bottom of the case 33, a metal through-wiring (second electrical connection portion) 34 that penetrates the case 33 and is connected to the outside of the side surface is provided at a position corresponding to the solder bump 24 of the image pickup device main body 12 to be stored. Yes. The through wiring 34 is electrically connected to the solder bump 24 of the image pickup device body 12 housed in the recess 28. A plurality of connection terminals 35 are provided on the side surface of the case 33 at positions corresponding to the through wirings 34.

It is a cross-sectional view of a solid-state image sensor. (A) It is a cross-sectional view of an image pick-up element board | substrate. (B) It is a cross-sectional view of an image pick-up element main body. It is a cross-sectional view of an image sensor main body and a case. It is a cross-sectional view of the solid-state image sensor of another form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 32 Solid-state image sensor 12 Image sensor main body 13, 33 Case 14 Image sensor board | substrate 15 Light-receiving part 15a Micro lens array 16 Image sensor chip 17 Spacer 18 Cover glass 19 Silicon layer 20 Insulating layer 21 Bonding pad 22 Through-hole wiring 23 Insulating film 24 Solder bump (first electrical connection part)
25 Openings 26, 27 Adhesive 28 Recesses 29, 34 Through-wiring (second electrical connection part)
30, 35 Connection terminal 31 Filling resin

Claims (2)

A chip provided with a light receiving part on the front surface, a spacer provided on the chip so as to surround the light receiving part, a transparent cover provided on the spacer and covering the light receiving part, and a back surface of the chip An image pickup device body comprising: a first electrical connection portion provided;
An insulative case in which a recess for housing the image sensor body is formed, and the second electrical connection portion electrically connected to the first electrical connection portion of the housed image sensor is provided in the recess. Consists of
A solid-state image pickup device, wherein a gap generated in the recess containing the image pickup device main body is closed by a resin.   The solid-state image pickup device according to claim 1, wherein the case is made of ceramics.

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