JP2005079400A - Semiconductor device and imaging apparatus including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device wherein an IC chip is kept in a horizontal state and strongly joined onto a substrate. <P>SOLUTION: The semiconductor device 1 including: the substrate 10; a stand 11 formed on the substrate; and the IC chip 20 located on the stand, can be attained by the semiconductor device formed with a plurality of divided stand blocks 11-1 to 11-4 which are made by dividing the stand 11. Since the stand 11 with the IC chip 20 located thereon is divided into a plurality of the stand blocks 11-1 to 11-4, the substrate is exposed from parts among the stand blocks. Applying an adhesive 5 to the parts among the stand blocks and directly placing the lower side of the IC chip 20 onto the stand blocks 11-1 to 11-4 can join the both in a state that no adhesive 5 overrides the upper face of the stand blocks. Thus, the semiconductor device 1 is obtained, wherein the IC chip is strongly joined with the substrate while keeping the levelness of the IC chip. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor device including a substrate on which an IC chip is mounted. In particular, the present invention relates to a semiconductor device suitable for mounting an image sensor such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) in a predetermined posture.

  For example, Patent Document 1 discloses an imaging apparatus in which an imaging element such as a CCD is arranged. The apparatus disclosed in Patent Document 1 includes a distance setting unit between a substrate and an image sensor. The setting means is arranged at the bottom of the image sensor and functions as a pedestal that adjusts the focal position. This setting means is configured integrally with the image sensor, and employs another substrate or a paste material used for mounting. As shown in Patent Document 1, when an IC chip for imaging such as a CCD is mounted on a substrate, it is necessary to accurately place the IC chip at a planned mounting position, and also consider the position in the optical axis direction.

  Also, an adhesive is often used when mounting an IC chip directly on a substrate or on a pedestal such as a die pad. For example, Patent Document 2 discloses a problem relating to an adhesive in flip chip mounting in which a bare chip is mounted on a substrate as it is, and a solution to the problem. In Patent Document 2, a plurality of radial grooves are formed in the substrate in order to solve the problem in the case where the amount of adhesive used for connecting the IC chip is too large. If comprised in this way, since an adhesive agent can be made to flow toward the periphery from a center, it can suppress that an adhesive agent is unevenly distributed. Further, the protruding adhesive is accommodated in a peripheral groove provided on the tip side.

JP 2002-27311 A Japanese Patent Laid-Open No. 2001-230274

  As shown in Patent Document 1, a semiconductor device in which an IC chip for imaging such as a CCD (hereinafter simply referred to as a CCD) is mounted on a substrate is provided with a pedestal for mounting the CCD on the substrate, and an adhesive is used. The technique of adhering the CCD onto the pedestal is widely used. FIG. 5 is a view showing an overview of a conventional manufacturing process of a semiconductor device in which a CCD is mounted on a substrate. FIG. 5A is a plan view in a state where an adhesive is disposed on a substrate, FIG. 5B is a diagram showing a state where a CCD is disposed on the adhesive, and FIG. 5C is A- in FIG. It is A sectional drawing.

  As shown in FIG. 5A, an adhesive 105 is disposed on a pedestal 101 on the substrate 100. A plurality of terminals 102 are formed on the substrate 100. Then, as shown in FIG. 5B, the CCD 110 is placed so as to be pressed from above the adhesive 105, and the connection pads 111 and the terminals 102 on the CCD side are wire-bonded. However, when the state at this time is viewed from the side, as shown in FIG. 5C, the thickness of the adhesive 105 may become uneven and the CCD 110 may be inclined. Thus, when the CCD 110 as the imaging element is tilted, the imaging function of the manufactured semiconductor device is deteriorated.

  Further, in the manufacturing method shown in FIG. 5, since the CCD 110 is simply pressed from the adhesive 105, bubbles are easily mixed in the adhesive and voids are easily generated. Since such voids cause cracks and reduce strength, the reliability of the semiconductor device is reduced.

  In the technique disclosed in Patent Document 2, the radiation groove is formed directly on the substrate. Then, an adhesive is disposed between the substrate and the IC chip, and the IC chip is pressed and fixed to the substrate side. At this time, the adhesive is interposed between the substrate surface and the IC chip mounting surface to bond them together. Too much adhesive enters the groove, but the adhesive between the substrate surface and the IC chip mounting surface contributes to adhesion. Therefore, when the adhesive on the substrate surface becomes non-uniform, the IC chip is inclined as described above. Therefore, even when an image pickup device such as a CCD is placed on the substrate using the technique shown in Patent Document 2, there is a possibility that the problem of tilt similarly occurs. Furthermore, in this patent document 2, since it is necessary to prepare the board | substrate which formed the groove | channel specially, cost will raise.

  As described above, in the conventional semiconductor device, when an IC chip is fixed on a substrate using an adhesive, it is difficult to arrange the IC chip without inclining. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a semiconductor device that solves such problems and holds an IC chip in a horizontal state with a simple configuration and is firmly bonded to a substrate.

  The object is a semiconductor device including a substrate, a pedestal portion formed on the substrate, and an IC chip placed on the pedestal portion, and a semiconductor formed by a pedestal block obtained by dividing the pedestal portion into a plurality of parts. This can be achieved with the device. In the present invention, since the pedestal portion on which the IC chip is placed is divided into a plurality of pedestal blocks, the substrate is exposed at the portion between the pedestal blocks. If an adhesive is disposed between the pedestal blocks and the lower surface of the IC chip is placed directly on the pedestal block, the two can be bonded without the adhesive getting on the upper surface of the pedestal block. Therefore, it is possible to provide a semiconductor device that is firmly bonded to the substrate while maintaining the level of the IC chip.

  The pedestal block preferably includes a pedestal block that supports at least four corners of the IC chip, and a space communicating with the outside is formed between the pedestal blocks when the IC chip is placed. . With such a structure, the internal air can be efficiently discharged to the outside side while the adhesive is filled in the space. Therefore, generation | occurrence | production of a void can be suppressed.

  Further, each of the pedestal blocks arranged at the four corners preferably has a structure including an outer edge portion protruding outward from the outer periphery of the IC chip when the IC chip is placed. Thus, if the outer edge part which protrudes to the exterior side is provided, the IC chip can be reliably placed at the intended placement position using this as a mark. Then, it is possible to obtain a strong structure in which the space is filled with an adhesive, and the IC chip and the substrate are bonded via the adhesive.

  The pedestal block can be formed as a metal pattern formed on the substrate. When the terminal pattern or the like is formed, it may be formed at the same time. In the case of an imaging apparatus including the semiconductor device, since an IC chip for IC imaging such as a CCD or SMOS is arranged at a predetermined position on the substrate with high positional accuracy, a clear captured image can be obtained.

  As described above, according to the present invention, it is possible to provide a semiconductor device that stably supports an IC chip such as a CCD with a level of horizontality.

  Hereinafter, a semiconductor device according to an embodiment of the present invention will be described with reference to the drawings. 1A and 1B are diagrams illustrating an outline of a manufacturing process of a semiconductor device 1 according to an embodiment. FIG. 1A is a plan view illustrating a state in which an adhesive is disposed on a substrate, and FIG. It is the figure which showed the state which has arrange | positioned on the adhesive agent which demonstrates CCD as an example. FIG. 2 is a cross-sectional view taken along the line BB in FIG.

  A pedestal 11 is formed on the surface of the substrate 10 of the semiconductor device 1 together with a number of terminals 12. The pedestal portion 11 is composed of a plurality (four pieces in FIG. 1) of pedestal blocks 11-1 to 11-4. These pedestal blocks 11-1 to 11-4 can be configured by metal patterns formed on the substrate by plating, for example. It is desirable to use Au as the metal used for the metal pattern. The pedestal blocks 11-1 to 11-4 are preferably formed so that the level difference from the surface of the substrate 10 is about 5 to 6 μm. The pedestal blocks 11-1 to 11-4 may be formed on the substrate 10 at the same time when the terminals 12 are pattern-formed. Thereby, since the manufacturing process only for each base block becomes unnecessary, a manufacturing process can be simplified.

  The pedestal blocks 11-1 to 11-4 shown in FIG. 1 are substantially L-shaped, and are arranged independently so as to support the four corners of the CCD 20 from the lower end corresponding to the planned placement positions of the CCD 20. Therefore, the substrate 10 is exposed (exposed) between the central portion surrounded by the base blocks 11-1 to 11-4 and between the base blocks. As shown in FIG. 1 (A), the adhesive 5 is desirably disposed almost at the center. Here, it is preferable that the planned mounting position of the CCD 20 is a position where an optical axis (not shown) of the light receiving unit of the CCD 20 substantially coincides with an optical axis of a lens 30 described later.

  As the adhesive 5 to be used, a conductive and insulating adhesive can be selected and used according to the connection form between the CCD 20 and the substrate 10. Silver paste can be suitably used as the conductive adhesive, and epoxy resin can be suitably used as the insulating adhesive. These adhesives are desirably thermosetting. The adhesive 5 may be fluid or sheet. The adhesive 5 is not limited to the above, and can be changed as appropriate.

  FIG. 1B shows a state in which the external appearance of the semiconductor device 1 is completed by mounting the CCD 20 on the central portion from the state of FIG. The CCD 20 is set so that its four corners are positioned on the four pedestal blocks 11-1 to 11-4. Therefore, an area surrounded by the base blocks and the bottom of the CCD 20 becomes one space SP. And between the adjacent base blocks, a passage 7 is formed to communicate this space SP with the outside. That is, by closing the CCD 20 from above, the space SP formed is in a state where it is communicated from the center to the outside via the passages 7 formed vertically and horizontally in FIG.

  In the manufacturing process, as shown in FIG. 1A, a predetermined amount of the adhesive 5 is placed in the center of the space, and then the CCD 20 is placed from above. At that time, it is desirable to increase the fluidity of the adhesive 5 by using a heating tool as necessary. Due to the bottom of the CCD 20, the pushed adhesive 5 flows toward the passage 7 while filling the space SP. Therefore, if air bubbles are not mixed in the adhesive 5 itself, the space is filled with the adhesive 5 while the internal air is efficiently pushed outward, so that no void is generated. The CCD 20 includes a connection pad 21 and is wire-bonded to the terminal 12 on the substrate 10 side.

  Here, the amount of the adhesive 5 to be used is a volume equivalent to the space SP or slightly larger than this. If the amount of the adhesive 5 is defined in this way, the adhesive 5 does not climb onto the base blocks 11-1 to 11-4 when the CCD 20 is pressed. Therefore, the mounted CCD is not tilted by the non-uniform adhesive interposed between the pedestal and the CCD as in the prior art. That is, in the present semiconductor device 1, the mounting surface (lower surface) of the CCD 20 is placed in direct contact with the upper surface of the pedestal blocks 11-1 to 11-4, so that the CCD 20 tilts while maintaining the level. There is no. This can be confirmed by FIG. 2 showing a cross section of 1 (B). Since the CCD 20 is placed on the upper surface of the pedestal blocks 11-1 to 11-4 formed smoothly by Au plating or the like, the horizontal state can be reliably maintained.

  In addition, the inventor of the present application obtained a stronger adhesive force when the CCD is directly bonded to the substrate using the adhesive than when the CCD is bonded to the metal base using the adhesive. It is confirmed that As shown in FIG. 1 (B), the semiconductor device 1 has an adhesive 5 interposed between the semiconductor substrate 1 and the substrate 10 below the CCD 20, so that the metal base portion is bonded with an adhesive interposed therebetween. In comparison, a structure in which the CCD 20 is more firmly fixed on the substrate 10 can be realized.

  Further, other functions performed by the pedestal blocks 11-1 to 11-4 will be described. These pedestal blocks 11-1 to 11-4 are designed to have a planar shape so that the expected placement position can be confirmed when the CCD 20 is placed. As can be confirmed by comparing FIG. 1A and FIG. 1B, the outer edges of the pedestal blocks 11-1 to 11-4 formed in an L shape rather than the outer periphery of the CCD 20 with the CCD 20 mounted. The portion 11PR is slightly protruding. Thus, by forming the outer edge portion 11PR of the pedestal blocks 11-1 to 11-4 so as to slightly protrude, the CCD 20 can be placed while checking the expected placement position.

  As described above, in the present semiconductor device 1, the CCD 20 is positioned in the height direction on the top surfaces of the pedestal blocks 11-1 to 11-4, and the positioning in the in-plane direction is the pedestal blocks 11-1 to 11-4. The outer edge portion 11PR is used. Therefore, the CCD 20 can be reliably arranged at a predetermined position on the substrate 10.

  FIG. 3 shows an example of the shape improvement of the pedestal blocks 11-1 to 11-4. (A) shows an example in which only the widths of the left and right passage portions 7L and 7R are narrowed, and (B) shows an example in which the widths of the upper and lower passages 7U and 7D are further widened. The pedestal blocks 11-1 to 11-4 shown in this improved example are devised so that the extruded adhesive 5 does not come into contact with the pattern of the terminals 12 located on the left and right. That is, when the CCD 20 is disposed at the top, the left and right passage portions 7L and 7R are narrowed in the portion that becomes the passages 7U and 7D. When formed in this way, a large amount of the adhesive 5 flows toward the upper and lower passages 7, so that contact between the adhesive 5 and the terminals 12 can be suppressed.

  In the present semiconductor device 1, since no adhesive is interposed between the pedestal portion and the CCD 20, there is no problem that the CCD is inclined as in the prior art. Moreover, since the CCD is placed on the upper surface of the flat pedestal formed by plating or the like, the horizontal state can be maintained. Further, since the adhesive 5 is interposed between the substrate 10 and the CCD 20, both can be firmly bonded.

  FIG. 4 is a diagram showing an imaging device 30 in which the semiconductor device 1 is incorporated. The imaging device 30 includes a lens barrel 31 fixed to the substrate 10 and a lens holder 32 slidably connected to the lens barrel 31 in the optical axis direction. A lens 33 is fixed to the lens holder 32. Since the CCD 20 is arranged at a predetermined position on the substrate 10 with high positional accuracy, the imaging device 30 can obtain a clear captured image.

  The preferred embodiment of the present invention has been described in detail above. However, the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the gist of the present invention described in the claims. Deformation / change is possible. For example, in the above embodiment, the IC chip is described as a CCD, but the present invention is not limited to this. The present invention can be widely applied to a semiconductor device including an IC chip that needs to be placed at a predetermined position with high accuracy while maintaining levelness. Moreover, in the said embodiment, although the shape of the base block was L-shaped, it is not restricted to this. What is necessary is just to change suitably the shape and number of base blocks as needed.

It is the figure which showed the outline of the manufacturing process of the semiconductor device which concerns on embodiment. (A) is the top view which shows the state which has arrange | positioned the adhesive agent to a board | substrate, (B) is the figure which showed the state which has arrange | positioned the IC chip on the adhesive agent. It is BB sectional drawing of FIG.1 (B). It is a figure showing about the example of improvement of the shape of a base block. It is the figure which showed the imaging device incorporating the semiconductor device. It is the figure which showed the general appearance of a mode that the semiconductor device which mounted CCD on the board | substrate conventionally is manufactured.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor device 5 Adhesive 10 Board | substrate 11 Base part 11-1 to 11-4 Base block 20 CCD
SP space PR outer edge

Claims (6)

A semiconductor device comprising a substrate, a pedestal portion formed on the substrate, and an IC chip placed on the pedestal portion,
A semiconductor device, wherein the pedestal portion is formed by a pedestal block divided into a plurality of parts. The pedestal block includes a pedestal block that supports at least four corners of the IC chip, and a space that communicates with the outside when the IC chip is placed is formed between the pedestal blocks. Item 14. The semiconductor device according to Item 1. 3. The semiconductor device according to claim 2, wherein each of the pedestal blocks disposed at the four corners includes an outer edge portion protruding outward from an outer periphery of the IC chip when the IC chip is placed. 4. The semiconductor device according to claim 2, wherein the space is filled with an adhesive, and the IC chip and the substrate are bonded via the adhesive. The semiconductor device according to claim 1, wherein the pedestal block is formed as a metal pattern formed on the substrate. An imaging apparatus comprising the semiconductor device according to claim 1.

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