JP2006034458A - Solid-state image pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid-state image pickup device capable of being miniaturized further by reducing a solid-state image pickup element without damaging the layout, or the like, of a substrate loaded with electric components, or the like. <P>SOLUTION: Pad parts 32b for connection are arrayed on the surface on the side of a lower side which is one side of the light receiving surface 32a of an image pickup element chip 32. Thus, a wiring pattern region inside the image pickup element chip 32 is reduced and the height dimension of the image pickup element chip is reduced by an arrow (a). An inner lead 36a is connected from the lower side to the pad part 32b for the connection and an inner lead 37a is connected from an upper side through the light receiving surface 32a to the pad part 32b for the connection. At the time of bending the inner leads 36a and 37a connected to the pad part 32b for the connection by roughly 90 degrees and arranging them in parallel position relation on the back side of the light receiving surface 32a, the inner lead 36a is bent with a prescribed interval to the lower side and the inner lead 37a is bent closely to the upper side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a solid-state imaging device disposed at a distal end portion of an electronic endoscope.

  In recent years, endoscopes that can observe an affected area in a body cavity by inserting an elongated insertion section into the body cavity are widely used. As this endoscope, for example, there is an electronic endoscope in which a solid-state imaging device in which a solid-state imaging device such as a charge coupled device is provided at the distal end portion of an insertion portion. In this electronic endoscope, an optical image picked up by a solid-state image sensor is converted into a video signal by a signal processing means, and an endoscope image is displayed on a display device for observation.

  For example, in a solid-state imaging device disclosed in Japanese Patent Application Laid-Open No. 5-115435, an electrical component 1 such as an IC or a capacitor is provided as shown in a front view and a side view illustrating the configuration of a conventional solid-state imaging device in FIG. In consideration of the layout of the mounted substrates (flexible substrates) 2, 3, connection pad portions 5,..., 5 are provided on two opposing sides around the light receiving surface 4 a of the solid-state imaging device 4. 5, 5 are connected to the inner leads 2a, 3a of the flexible substrates 2, 3 via metal protrusions 6. The inner leads 2a and 3a connected to the connecting pad portion 5 are bent to the opposite side to the light receiving surface 4a so as to be arranged side by side on the back side of the light receiving surface.

  However, by dispersing the connecting pad portion around the light receiving surface, the area of the in-chip wiring pattern is increased and complicated, and a region for providing the connecting pad portion is required. There was a problem that the image sensor becomes large.

  The present invention has been made in view of the above circumstances, and provides a solid-state imaging device capable of reducing the size of the solid-state imaging device and further reducing the size without impairing the layout or the like of a substrate on which electrical components or the like are mounted. It is aimed at that.

A solid-state imaging device of the present invention is a solid-state imaging device comprising a connecting pad portion provided around the light receiving surface of an imaging element chip and a flexible substrate having an inner lead connected to the connecting pad portion. ,
At least one of the inner leads connected to the connection pad portion is bent toward the back surface of the light receiving surface on the other side different from the side on which the connection pad portion is provided.

  According to this structure, the inner lead is bent to the back side of the light receiving surface on the other side different from the side on which the connection pad is provided, so that the inner lead is provided with the connection pad. Compared to the case of bending on the side where the solid-state image sensor is bent, the solid state image sensor is made smaller by bringing the inner lead closer to the other side.

  According to the present invention, it is possible to provide a solid-state imaging device capable of further reducing the size by reducing the size of the solid-state imaging device without impairing the layout or the like of the substrate on which the electrical component or the like is mounted.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 relate to an embodiment of the present invention, FIG. 1 is a diagram illustrating a solid-state imaging device, FIG. 2 is a front view of the solid-state imaging device of FIG. 1, and the solid-state imaging device of the present embodiment and a conventional solid-state device. It is a figure which compares the external shape with an image sensor.

  As shown in FIG. 1, the solid-state imaging device 10 of the present embodiment is mainly composed of an objective lens unit 20 and an imaging element unit 30.

  The objective lens unit 20 includes a lens frame 21 and a plurality of objective optical components 22. These objective optical components 22 are fixed in the lens frame 21 by bonding or adhesion.

  On the other hand, the image sensor unit 30 has a solid-state image sensor 31. This solid-state imaging device 31 is provided with a light receiving surface 32a having a predetermined area and a connecting pad portion (see reference numeral 32b in FIG. 2) which is a connection portion for transmitting a driving signal and an output signal of the solid-state imaging device 31 and a driving power source. The chip 32 and a cover glass 33 fixed to the front surface of the imaging element chip 32 with a transparent adhesive.

  An objective optical component 34 made of, for example, a parallel plate is fixed to the front surface of the cover glass 33, and the element frame 23 is fitted and fixed to the outer peripheral surface of the objective optical component 34. Then, the element frame 23 and the lens frame 21 are joined, and the imaging element unit 30 and the objective lens unit 20 are integrated to constitute the solid-state imaging device 10.

  As shown in FIGS. 1 and 2, a predetermined number of connecting pad portions 32b,..., 32b arranged on the light receiving surface 32a side of the image sensor chip 32 are mounted with electrical components 35 such as ICs and capacitors. The leading ends of the inner leads 36 a and 37 a of the flexible substrates 36 and 37 are electrically connected via the metal protrusions 38.

  As shown in FIG. 2, in the solid-state imaging device 31 of the present embodiment, the connecting pad portions 32b,..., 32b are arranged on the lower side surface in the drawing, which is one side of the light receiving surface 32a of the imaging device chip 32. . As a result, the wiring pattern region provided in the image sensor chip 32 can be reduced, and the height dimension of the image sensor chip can be decreased by the arrow a.

  The inner lead 36a of the flexible substrate 36 is connected from the lower side to the connecting pad portion 32b on the lower side surface. On the other hand, the inner lead 37a of the flexible substrate 37 is connected to the connecting pad portion 32b on the lower side surface through the light receiving surface 32a of the imaging element chip 32 from the upper side. Specifically, the inner lead 37a is passed over the optical black 32c that does not affect the imaging of the light receiving surface 32a.

  The inner leads 36a and 37a connected to the connecting pad portion 32b are bent by approximately 90 degrees, and the flexible substrates 36 and 37 are arranged on the back side of the light receiving surface 32a so as to be parallel to the axial direction. At the time of the bending, the inner lead 36a is bent with a predetermined interval b (see FIG. 1) with respect to the lower side in consideration of the load on the connecting pad portion 32b. Bending is performed at a position close to the upper side as shown by the dimension c (see FIG. 1) without considering the load on the connecting pad portion 32b. As a result, the inner lead 37a can be bent at a position close to the upper side without considering the load on the connecting pad portion 32b, so that the amount of protrusion from the end side of the inner lead 37a is smaller than that of the inner lead 36a. Can be reduced.

  The electrical components 35 mounted on the flexible boards 36 and 37 are arranged on the inner side so as to face each other. Further, a signal line 39a and a coaxial cable 39b inserted through the signal cable 39 are electrically connected to the base end portions of the flexible boards 36 and 37.

  Thus, by providing a predetermined number of connecting pad portions on one side, the wiring pattern region provided in the image sensor chip can be reduced, and the area of the image sensor chip can be reduced.

  Further, when the inner leads of the two flexible boards disposed so as to face the back surface side of the light receiving surface of the image sensor chip are electrically connected to the connecting pad portion, the connecting pad portion is provided on one side of the side where the connecting pad portion is provided. The inner lead of the flexible board arranged on the opposite other side is passed through the light receiving surface side of the image sensor chip and connected to the connecting pad, so that the inner lead is bent at a position close to the other side. Thus, the amount of protrusion from the end of the inner lead can be reduced.

  Accordingly, the solid-state imaging device can be reduced in size and the solid-state imaging device can be further reduced in size without changing the layout such as the arrangement position of the flexible substrate.

  For the purpose of reducing the size of the solid-state imaging device, the solid-state imaging device may be formed in a small size by reducing the number of pixels of the solid-state imaging device. In that case, a solid-state imaging device is configured as shown in FIGS. 3 (a) and 3 (b).

  As shown in FIGS. 3A and 3B, the solid-state imaging device 41 according to the present embodiment has a specification that is downsized. Therefore, all the connecting pad portions 42b provided in the imaging device chip 42 have been described above. It is impossible to arrange them on the lower side.

  Therefore, some connecting pad portions 42b are provided at predetermined positions on the upper side opposite to each other with the light receiving surface 42a interposed therebetween. Further, in order to reduce the size of the solid-state imaging device, the single flexible substrate 43 connected to the connecting pad portion 42b is provided.

  The inner leads 43a of the flexible substrate 43 are connected from the lower side to the connecting pad portions 42b on the lower side and upper side surfaces. At this time, the inner lead 43a connected to the connecting pad portion 42b on the upper side surface passes through the light receiving surface side of the imaging element chip 32 from the lower side. Specifically, the inner lead 43a passes outside the light receiving surface 32a. Reference sign 42c is optical black.

  As described above, in this embodiment, since the wiring pattern regions are provided on the upper side and the lower side, the area of the image pickup device chip does not change so much, but the flexible substrate connected to the connecting pad portion is 1 By constituting the sheet, it is possible to reduce the size of the inner lead by bending the inner lead at one place on the lower side. As a result, it is possible to further reduce the size of the solid-state imaging device that has been reduced in size.

  Conventionally, the inner leads 52 of the image sensor chip 51 have been provided on opposite sides as shown in the drawing for explaining the configuration of the image sensor in FIG. For this reason, when a color filter (not shown), a cover glass 53 or the like (not shown) is bonded and fixed on the light receiving surface 51 a of the image pickup device chip 51 with the transparent adhesive 54, mechanical positioning is difficult.

  For this reason, in this embodiment, the inner leads 52 of the image sensor chip 51 are provided on one side or two adjacent sides. As a result, the two sides of the image sensor chip 51 and the cover glass 53 are attached to a jig 55 as shown in the configuration example in FIG. By performing adhesion and fixing in the abutted state, it is possible to improve the positional accuracy between the imaging element chip 51 and the cover glass 53.

  By the way, conventionally, in the solid-state imaging device, the entire circumference of the light receiving surface is covered with an adhesive or a sealing resin so that moisture does not enter the light receiving surface. However, when the entire periphery is covered with an adhesive (sealing resin), the adhesive (sealing resin) may flow into the light receiving surface. In order to prevent this inflow, conventionally, the bonding portion and the sealing portion have been enlarged, which has been a factor in increasing the size of the solid-state imaging device.

  For this reason, in the present embodiment, a step 61 is formed around the light receiving surface 51a of the image sensor chip 51, as shown in a diagram for explaining a configuration example of the image sensor chip in FIG. As shown in FIG. 5B illustrating another configuration example of the image sensor chip, a groove 62 is formed around the light receiving surface 51a, or another configuration example of the image sensor chip in FIG. 5C is described. As shown in the figure, a protrusion 63 is formed around the light receiving surface 51a to prevent the adhesive 54 or the sealing resin from entering. This can reduce the size of the solid-state imaging device. Other configurations are the same as those of the above-described embodiment, and the same members are denoted by the same reference numerals and description thereof is omitted.

  By the way, conventionally, when an air layer is provided between the light receiving surface of the image sensor chip and the cover glass, the cover glass is inclined and attached to the light receiving surface. There was a risk of adverse effects on performance.

  For this reason, in this embodiment, a perspective view for explaining a configuration for preventing the flow of adhesive or the like into the light receiving surface of FIG. 6A, and a height control pad portion and a connection pad portion of FIG. 6B. As shown in FIG. 6A and FIG. 6C, which shows an image sensor in which a uniform air layer is formed between the light receiving surface and the cover glass, predetermined protrusion heights are provided at the four corners of the image sensor chip 51. Of the air layer 72 formed between the light receiving surface 51 a and the cover glass 53 by placing the cover glass 53 on the height control pad 71. The thickness is uniform.

  The height control pad portion 71 has a protruding height higher than that of the other connection pad portions 73. Further, the height control pad 71 may have an electrical connection effect similarly to the connection pad 73 even if it is merely for height adjustment.

  By the way, conventionally, when an air layer is provided between the light receiving surface and the cover glass by bonding the light receiving surface side of the imaging element chip and the cover glass, there is a possibility that an adhesive or a sealing resin may flow into the light receiving surface. .

  Therefore, in this embodiment, in order to form an air layer 72 between the image pickup device chip 51 and the cover glass 53 as shown in FIG. 7, the entire periphery of the light receiving surface 51a is bonded to the adhesive 54 (or sealing resin). ) And the like, the nozzle 81 is disposed inside the air layer 72, and the air layer 72 side is pressurized to a constant pressure to seal the imaging element chip 51 and the cover glass 53.

  As a result, the internal pressure of the air layer becomes higher than the external air pressure, and the adhesive 54 is prevented from flowing into the light receiving surface 51a side, and the thickness of the air layer can be controlled. Contrary to the above, the same effect can be obtained even if the outside air is set to a negative pressure and the pressure on the air layer side is set higher than the surroundings.

  It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention.

[Appendix]
According to the embodiment of the present invention as described above in detail, the following configuration can be obtained.

(1) In a solid-state imaging device including a connecting pad provided around the light receiving surface of an imaging element chip, and a flexible substrate having an inner lead connected to the connecting pad.
A solid-state imaging device in which at least one of inner leads connected to the connecting pad portion is bent toward the back surface of the light receiving surface on the other side different from the side on which the connecting pad portion is provided.

(2) The solid-state imaging device according to appendix 1, wherein at least one of the inner leads passes through the light receiving surface and is connected to the connecting pad portion.

(3) The solid-state imaging device according to attachment 2, wherein the inner lead passes over the optical black.

(4) The solid-state imaging device according to appendix 1, wherein when the connecting pad portion is arranged on one side, the inner lead connected to the connecting pad portion is bent on one side and the other side different from the side. .

(5) The solid-state imaging device according to appendix 1, wherein when the connecting pad portion is provided on different sides, the inner leads connected to the connecting pad portion are bent on the same side.

1 and 2 relate to an embodiment of the present invention, and FIG. 1 is a diagram illustrating a solid-state imaging device. FIG. 1 is a front view of the solid-state image sensor of FIG. 1 and a diagram for comparing the outer shapes of the solid-state image sensor of this embodiment and a conventional solid-state image sensor Front view and side view for explaining another configuration of the solid-state imaging device The figure which shows the structural example which aims at the improvement of the positional accuracy of an image pick-up element chip | tip and a cover glass. The figure which shows the structural example which prevents the flow of the adhesive agent (sealing resin) to a light-receiving surface The figure which shows the structural example which makes the thickness of the air layer formed between a light-receiving surface and a cover glass uniform. The figure which shows the structural example which can control the thickness of an air layer while preventing that an adhesive agent flows into the light-receiving surface side. The figure explaining the structure of the conventional solid-state image sensor

Explanation of symbols

10 ... Solid-state imaging device
31 ... Solid-state image sensor
32. Image sensor chip
32a ... Light receiving surface
32b ... Pad part for connection 36 ... Flexible substrate
36a ... Inner lead 37 ... Flexible substrate 37a ... Inner lead
Attorney Susumu Ito

Claims (1)

In a solid-state imaging device comprising a connecting pad portion provided around the light receiving surface of an imaging element chip and a flexible substrate having an inner lead connected to the connecting pad portion,
Solid-state imaging characterized in that at least one of the inner leads connected to the connecting pad portion is bent to the light receiving surface back side on the other side different from the side on which the connecting pad portion is provided. apparatus.

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