JP2005347556A - Solid-state imaging element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state imaging element with a small size, low profile, high yield and high reliability for providing excellent sealing workability, by preventing an adhesive or a sealing resin from oozing out to an effective light receiving area so as to prevent deterioration in the imaging characteristic. <P>SOLUTION: The solid-state imaging element wherein a micro lens is formed on the surface of a light receiving element is configured such that at least one side of a range formed with the micro lens is nearly in matching with the edge of the effective light receiving area of the solid-state imaging element. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a solid-state image sensor, and more particularly to a solid-state image sensor in which a microlens is formed on the surface of a light-receiving element.

  In recent years, solid-state imaging devices such as CCD and CMOS sensors have been mounted not only on digital cameras, but also on personal computers, mobile phones, etc., and there is an increasing demand for smaller and thinner mounting forms. .

  In order to satisfy these requirements, a solid-state imaging device with a microlens has been proposed. A solid-state imaging device with a microlens mounted on a substrate is shown in FIGS. FIG. 5 is a plan view of a solid-state imaging device, and FIG. 6 is a cross-sectional view of a solid-state imaging device including a substrate and a solid-state imaging device mounted on the substrate. In these drawings, a solid-state image sensor 101 with a microlens 103 is mounted on a substrate 106 made of a flexible substrate or the like having an opening 106 a facing the light receiving area 102 of the solid-state image sensor 101. The electrode pad 105 of the solid-state imaging device 101 is electrically connected to a wiring pattern formed on one surface of the substrate 106 via a bump 104a by an adhesive 104 such as an anisotropic conductive adhesive. A translucent member 107 is bonded to the other surface of the substrate 106.

  As a result, a space is formed between the microlens 103 formed on the surface of the solid-state imaging device 101 and the translucent member 107. For example, in order to prevent moisture, dust and the like from entering the space, The solid-state imaging device disclosed in Kaihei 08-148666 is configured such that the space of the opening 106a is hermetically sealed. Such a solid-state imaging device has many advantages such that the entire device can be reduced in size and thickness, and can be prevented from dew condensation and imaging degradation on the imaging region, thereby ensuring reliability.

  However, in the case of the structure of the solid-state imaging device disclosed in Japanese Patent Application Laid-Open No. 08-148666, the entire periphery of the surface of the solid-state imaging device 101 is surrounded by an adhesive 104 such as an anisotropic conductive adhesive so as to surround the light receiving area 102. In order to adhere, the adhesive 104 such as the anisotropic conductive adhesive may ooze out to the light receiving area 102 side. Specifically, as shown in FIG. 7, the adhesive 104 flows into the grooves 110 a between the plurality of convex lenses 110 on the surface of the microlens 103 due to capillary action. In particular, as shown in FIG. 5, when the electrode pad 108 of the solid-state imaging device 101 is only in two directions, the adhesive 104 such as an anisotropic conductive adhesive must be applied in two directions without the electrode pad 108. In this case, since there is no wiring pattern in this direction, the adhesive 104 easily flows out, and it is difficult to secure the yield.

  Therefore, in the above structure, there is a problem in that the yield decreases due to the adhesive 104 such as an anisotropic conductive adhesive oozing out into the light receiving area 102. Furthermore, there is a problem that the imaging characteristics of the solid-state imaging device 101 deteriorate due to the influence of the adhesive 104 that has oozed out.

  Further, the formation range of the conventional microlens 103 of the solid-state imaging device 101 is conventionally substantially matched with the formation range of the color filter formed larger than the light receiving area 102 in order to make the film thickness uniform. The distance between the bonding portion and the microlens region is close by a distance L1, generally a distance of 200 μm or more, on the outer sides of the end portion 102a of the light receiving area 102 by four distances. Therefore, when the adhesive 104 in the bonding portion oozes out, the adhesive 104 easily reaches the region of the microlens 103 as shown in FIG. Once the adhesive 104 reaches the surface of the microlens 103, the adhesive 104 spreads to the effective light receiving area 102 due to capillary action, and this causes the adhesive 104 to ooze into the light receiving area 102. It was a big cause of.

In order to solve the above problem, Japanese Patent Application Laid-Open No. 2002-124654 discloses the distance from the end surface of the opening 106a of the substrate 106 to the microlens region as the distance between the surface of the solid-state imaging device 101 and the substrate 106 (adhesive agent). A proposal has been disclosed in which a dike or a groove is provided on the surface of the solid-state imaging device 101 or the opening end of the substrate 106, which is 2.5 times or more of the thickness (104).
Japanese Patent Laid-Open No. 08-148666 JP 2002-124654 A

  However, in the case of the solid-state imaging device described in Japanese Patent Application Laid-Open No. 2002-124654, the opening 106a of the substrate 106 is configured to be larger than necessary, and a dike, a groove, or the like is formed at the end of the surface of the solid-state imaging device 101. However, there is a problem that the cost increases. Furthermore, according to the proposal described in Japanese Patent Application Laid-Open No. 2002-124654, it is against the request to reduce the chip size.

  The present invention has been made in view of the above problems, and enables reduction in the chip size, and further prevents the adhesive or sealing resin from oozing out to the light receiving area of the solid-state imaging device and improves the yield. An object of the present invention is to provide a solid-state imaging device having high reliability and yield by preventing deterioration of imaging characteristics.

  In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a solid-state imaging device in which a microlens is formed on a light receiving element surface, and the area where the microlens is formed is an end face of an effective light receiving area on at least one side. Is substantially the same.

  According to a second aspect of the present invention, in the solid-state imaging device in which the microlens is formed on the surface of the light receiving element, the range in which the microlens is formed corresponds to 10 columns of pixels outside the end face of the effective light receiving area on at least one side. It is characterized as follows.

  With the configuration as described above, the chip size is reduced, and the adverse effect on the imaging characteristics due to the seepage of the adhesive or the sealing member to the light receiving area is prevented, so that a solid-state imaging device with high yield and high reliability can be obtained. It becomes feasible.

  As described above based on the embodiments, according to the present invention, it is possible to prevent the adhesive or sealing resin from seeping into the effective light receiving area, thereby preventing the deterioration of the imaging characteristics, and the small and thin sealing. A high-yield and high-reliability solid-state imaging device with good workability can be obtained. In addition, the chip size of the solid-state image sensor can be reduced, and a smaller solid-state image sensor can be realized.

Next, the best mode for carrying out the present invention will be described.
FIG. 1 is a plan view of a solid-state imaging device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a solid-state imaging device including the solid-state imaging element and substrate of FIG.

  In FIG. 2, a solid-state imaging device 1 with a microlens 3, which is a semiconductor chip, is mounted on a substrate 6 made of a flexible substrate having an opening 6 a facing the effective light receiving area 2 of the solid-state imaging device 1. The An electrode pad 5 that is a protruding electrode of the solid-state imaging device 1 is electrically connected to a wiring pattern formed on one surface of the substrate 6 via a bump 4a by an adhesive 4 such as an anisotropic conductive adhesive. ing. The translucent member 7 is bonded to the other surface of the substrate 6 with an adhesive.

  A space is provided between the microlens 3 formed on the surface of the solid-state imaging device 1 and the translucent member 7, but the solid-state imaging device is configured so that moisture, dust, and the like do not enter the space. The adhesive 4 described above is provided around the effective light receiving area 2 so that the space of the opening 6a is hermetically sealed. A sealing resin may be used instead of the adhesive 4.

  Further, the substrate 6 is not limited to a flexible substrate, and may be a hard substrate such as ceramic, glass epoxy, or metal. The translucent member 7 may be glass, transparent resin such as vinyl chloride or acrylic, or an optical member such as a low-pass filter, an IR cut filter, a lens, or a prism.

  Furthermore, the electrode pad 5 includes a metal ball or a metal surface on the surface in addition to a stat bump such as Au or Cu formed by a wire bond method, a bump such as Au, Ag, Cu, In, or solder formed by a plating method. A plated resin ball, a conductive adhesive patterned by printing, or the like may be used.

  Here, a range R1 in which the microlens 3 is formed (hereinafter referred to as a microlens formation range) R1 substantially coincides with a range R2 in the effective light receiving area 2 (hereinafter referred to as an effective light receiving range) on at least one side. In other words, when the solid-state imaging device 1 is viewed from a direction orthogonal to the surface of the effective light receiving area 2, at least one side of the edge of the effective light receiving range R2, which is the edge 2a of the effective light receiving area 2, is formed as a microlens. It substantially coincides with the edge of the range R1.

  In more detail, as shown in FIG. 1, the microlens formation range R1 has dimensions of 10 pixels or 9 pixels or less outside the edge of the effective light receiving range R2 on each side. Only have a large range. Naturally, it is better that the number of pixels is 10 columns or less, and if possible, it is best to match the end face of the effective light receiving area 2 if possible. However, since the shape defect of the microlens 3 is likely to occur at the outermost peripheral end of the microlens formation range R1, it is preferable to form the microlens 3 to the outside of the effective light receiving area 2 up to about 5 to 10 columns of pixels. preferable.

  FIG. 3 is a diagram for explaining the edge of the microlens formation range R1 and the edge of the effective light receiving range R2. 4 is an enlarged cross-sectional view of a portion indicated by B in FIG. The microlens formation range R1 has a range that substantially coincides with each edge that is each of the four sides of the effective light receiving range R2, but as shown in FIGS. The effective light receiving range R2 is larger than the effective light receiving range R2 by a distance L1 outside the four sides. This L1 has a length of 10 pixels or less as described above.

  For example, when the size of one pixel is 5 μm, the distance L1 is 10 pixels, that is, 50 μm. Therefore, according to such a solid-state imaging device, since the distance between the electrode pad 8 and the microlens formation region R1 is about 150 μm as compared with the conventional product described above, even if the adhesive 4 in the electrode pad portion protrudes. It becomes difficult for the adhesive 4 to reach the microlens region. Therefore, it is possible to prevent the adhesive 4 from seeping out into the effective light receiving area 2, to prevent deterioration of the imaging characteristics of the solid-state imaging device 1, and to realize a solid-state imaging device with high yield and high reliability.

  As shown in FIG. 3, in the present embodiment, an example in which the four sides of the microlens formation range R1 substantially coincide with the edge of the effective light receiving range R2 has been described. In the case where the pad 5 is provided only in two directions or only in one direction, the adhesive 4 easily reaches the microlens 3 from the direction in which the electrode pad 5 exists. In such a case, it is only necessary to prevent the adhesive 4 from flowing into the microlens 3 from two directions or one direction where the electrode pad 5 exists, so that at least two sides or one side of the microlens formation range R1 is present. As long as it is substantially coincident with the edge of the effective light receiving range R2. Furthermore, when it is sufficient to prevent the adhesive 4 from flowing in only one direction, at least one side of the microlens formation range R1 corresponding to a certain direction of the electrode pad 5 is substantially the same as the edge of the effective light receiving range R2. It only has to be done.

  As described above, according to the present embodiment, it is possible to prevent the adhesive or the sealing resin from seeping out to the effective light receiving area, thereby preventing the deterioration of the imaging characteristics, and the small and thin structure with good sealing workability. A solid-state imaging device with high yield and high reliability can be obtained. In addition, the chip size of the solid-state image sensor can be reduced, and a smaller solid-state image sensor can be realized.

  Further, since the area of the microlens 3 is narrowed, the electrode pad portion can be brought closer to the effective light receiving area side even in a solid-state imaging device having the same effective light receiving area size, so that the chip size can be reduced and the size can be further reduced. A solid-state imaging device can be realized.

  The present invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

It is a top view of the solid-state image sensing device concerning an embodiment of the invention. It is sectional drawing of the solid-state imaging device containing the solid-state image sensor and board | substrate of FIG. It is a figure for demonstrating the edge part of the micro lens formation range R1 concerning embodiment of this invention, and the edge part of the effective light reception range R2. It is an expanded sectional view of the part shown by B of FIG. It is a top view of the solid-state image sensor concerning a prior art. It is sectional drawing of the solid-state imaging device containing the board | substrate concerning a prior art, and the solid-state image sensor mounted in the board | substrate. It is an expanded sectional view of the part shown by A of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid-state image sensor, 2 Effective light-receiving area, 3 Micro lens, 4 Adhesive, 5 Electrode pad, 6 Board | substrate, 6a Opening part, 7 Translucent member agent Patent attorney Susumu Ito

Claims (2)

A solid-state imaging device having a microlens formed on the surface of the light receiving element,
A solid-state imaging device, wherein at least one side of a range where the microlenses are formed substantially coincides with an edge of an effective light receiving area of the solid-state imaging device. The at least one side substantially coincides with the edge of the effective light receiving area of the solid-state imaging device within a distance of 10 columns outside the edge of the effective light receiving area. Solid-state image sensor.

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