JPH09146013A - Image pickup element assembly of electronic endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an endoscope small in diameter and simplify the internal constitution. SOLUTION: A CCD 18 has a color filter and microlenses 20 on its image pickup surface, and a circuit board 16 is interposed directly between the image pickup surface and a prism 15, and this circuit board 16 has an opening hole 21 for setting air gap and a wiring pattern 22 and a hole 23 for wiring for connecting the CCD 18 and a signal cable 25 together are formed. This circuit board 16 is adhered to both the CCD 18 and prism 15 with an adhesive while its opening hole 21 is positioned on the image pickup surface S, and consequently, the opening hole 21 is held airtight. Further, the terminal of the CCD 18 and the terminal 22A of the wiring pattern are connected together through the hole 23 for wiring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an assembly used in an image pickup section of an electronic endoscope and to which an image pickup device having a color filter or a microlens is assembled.

[0002]

2. Description of the Related Art FIG. 5 shows the structure of an image pickup element assembly provided at the tip of an electronic endoscope apparatus, which is viewed from the side. In FIG. 5, a cover glass 4 is connected to a lens barrel portion 2 having an objective lens system 1 via a prism 3, and the cover glass 4 is arranged so as to close an upper opening of a package 5. Inside the package 5, a CCD (charge
Coupled Device) 6 is arranged, the package 5 is attached to the circuit board 7, and the CCD 6 is electrically connected to the circuit board 7 via the package 5.

The CCD 6 is, for example, an interline CCD, and a color filter and a microlens, which are not shown, are formed on the image pickup surface on the upper surface thereof. This color filter is arranged to obtain a color image using a complementary color mosaic, for example, while the microlens is arranged to improve the light incident efficiency of the CCD 6 with respect to the photosensor. The CCD 6 on which the color filter is formed is attached in the package 5 in an airtight state (in some cases, deterioration preventing gas may be enclosed) so that the color filter is not discolored.

FIG. 6 shows the internal arrangement of the endoscope front end as viewed from the front side. The above-mentioned assembly body from the lens barrel portion 2 to the circuit board 7 includes the front end portion 8 of the assembly. It is arranged from the center to the upper side. Light guides 9A and 9B are arranged near both sides of the objective lens system 1, and a treatment instrument insertion channel 10 for leading out a treatment instrument such as forceps is provided below the circuit board 7. With such a configuration, when the inside of the observed body is illuminated by the light irradiation from the light guides 9A and 9B, the image inside the observed body is captured by the CCD 6 through the objective optical system 1.

[0005]

By the way, in the endoscope, it is a big problem to reduce the diameter and to simplify the structure, and in particular, in the endoscope for the bronchus, it is required to reduce the diameter of the distal end portion. In view of such requirements, the present invention focuses on the assembly of the image pickup device. That is, as shown in FIG. 6, the cover glass 4, the package 5 and the circuit board 7 occupy a length t1 in the radial direction of the tip portion 8. The diameter can be achieved.

The present invention has been made in view of the above points, and an object thereof is to attach an image pickup element assembly of an electronic endoscope capable of reducing the diameter of the endoscope and simplifying the internal structure. To provide.

[0007]

In order to achieve the above object, the invention according to the first aspect is to connect an image pickup device in which at least one of a color filter and a microlens is formed on an image pickup surface to an objective optical system. In the image pickup element assembly, a circuit board is provided between the image pickup surface of the image pickup element and the objective optical system, the circuit board being an image optical path and having an air gap portion for providing an air gap on the image pickup surface. In this circuit board, in order to connect the image pickup device and the signal cable, a wiring pattern formed on a surface on the objective optical system side that does not contact the image pickup surface of the image pickup device, and a terminal of the image pickup device. A wiring hole for connecting to the terminal of the wiring pattern formed on the objective optical system side is formed.

[0008] According to the configuration operation of the above, for example, a color filter is formed on the surface of the imaging device, a microlens is formed on the color filter, a circuit board having an air gap above the microlens Are adhered with an adhesive or the like, and the objective optical system is adhered onto the circuit board with an adhesive or the like. That is, the air gap portion is sized according to the imageable area. When the air gap portion is, for example, an opening hole (through hole), the upper surface of the opening hole is the objective optical system and the lower surface is the microlens. Due to the above, the inside of the opening hole is kept airtight.

In such an assembled body, the inside of the opening hole of the circuit board replaces the air gap which is conventionally present in the upper part of the package. Therefore, assuming that the thickness of the circuit board and the conventional cover glass of the package are the same, in the assembly of the present invention, the thickness of the air gap provided in the upper portion of the package is smaller than that of the conventional assembly. It gets shorter. Further, since the conventional circuit board arranged below the image pickup element is unnecessary, the thickness of this circuit board is shortened.

In order to connect the image signal from the image pickup device to the signal cable, a wiring pattern including an input / output terminal is formed on the circuit board, and an input / output terminal provided on the upper surface of the image pickup device is formed at this terminal. Will be connected. In addition to the above wiring pattern, circuit members such as a CCD drive circuit and an amplifier circuit are also provided.

Here, when the wiring pattern of the circuit board is formed on the upper surface of the board (on the side of the objective optical system), the image pickup device is arranged under the board, and therefore the terminals on the board side. It becomes difficult to connect the terminal to the terminal on the image sensor side. Therefore, in the present invention, a wiring hole is provided in the vicinity of the terminal on the circuit board, and the terminal on the image pickup device side and the terminal on the board side are connected by wire bonding through the wiring hole.

By the way, as a method of connecting the terminal on the image pickup device side and the terminal on the circuit board side, there is a method by pressure bonding using a bump device or the like, but this bump device is expensive.
On the other hand, the above-mentioned connection method by wire bonding has an advantage that existing equipment can be used without requiring special equipment and is advantageous in terms of cost.

[0013]

FIG. 1 is an exploded perspective view of an image pickup element assembly of an electronic endoscope according to an example of the embodiment.
2 shows an assembled state of the members of FIG. 1, FIG. 3 shows a connecting portion between the image pickup element and the circuit board, and FIG. 4 shows an assembled state of the image pickup element and the circuit board. The member shown in the drawing is arranged at the tip of the endoscope, and the objective lens system 12
The lens barrel 13 including the
5 is connected. The circuit board 1 is provided below the prism 15.
A CCD 18 is arranged via 6. As shown in FIG. 3, a color filter 19 is formed on the upper image pickup surface of the CCD 18, and a microlens (the figure is schematically enlarged) 20 is formed on the color filter 19. ing.

The circuit board 16 is made of synthetic resin, ceramic, metal or the like, and has a predetermined thickness t suitable for the material.
2 (about 0.1 mm to several mm), which can be used as a flexible substrate. This circuit board 16
1, a circular opening hole 21 is formed therethrough, and the opening hole 21 has a predetermined size that fits within the imageable area S of the CCD 18, as shown in FIG. In addition, the circuit board 16 has a wiring pattern 22 including an input / output terminal 22A as shown on the upper surface thereof, that is, on the prism 15 side.
And a wiring hole 23 is provided near the input / output terminal 22A on the CCD 18 side. On the other hand, an input / output terminal 24 is also provided on the upper surface of the CCD 18. Therefore, in this circuit board 16, the input / output terminal 22A of the wiring pattern 22 and the input / output terminal 24 of the CCD 18 are connected by wire bonding through the wiring hole 23, and the signal cable 25 is connected to the terminal at the rear end. Will be connected.

When the above-mentioned members shown in FIG. 1 are assembled, FIG.
The assembled body of is completed. That is, as shown in FIG.
The circuit board 16 has the opening hole 21 arranged at a predetermined position, and the wiring hole 23 is aligned with the upper portion of the input / output terminal 24 on the CCD 18, and the CCD 26 is bonded by the adhesive 26.
It is glued directly to the upper surface of 18. Then, as also shown in FIG. 4, the input / output terminals 24 and the wiring pattern 22 on the CCD 18 are passed through the positioned wiring holes 23.
The input / output terminal 22A is connected by wire bonding. Then, the prism 1 is placed on the circuit board 16.
5 is adhered to the periphery of the opening hole 21 with an adhesive 26.

A circuit member 27 for driving the CCD 18 or amplifying the output video signal of the CCD 18 is arranged at a predetermined position of the wiring pattern on the upper side of the circuit board 16 as shown in the figure.

According to such a structure of the assembly, the inside of the opening hole 21 of the circuit board 16 is maintained in an airtight state, and a predetermined color filter deterioration preventing gas is introduced into the opening hole 21. Can be encapsulated. Then, the CCD 1
8 is electrically connected to the signal cable 25 via the circuit board 16, whereby the video signal obtained by the CCD 18 can be taken out to the outside via the signal cable 25.

According to the above embodiment, as shown in FIG. 3, the air gap of height t2 is CC due to the opening 21.
It is formed between D18 (microlens 20) and the prism 15, and the air gap t3 in the package 5 shown in FIG. 5 disappears. Further, since the conventional circuit board 7 disposed below the CCD 18 is unnecessary, the thickness t4 of the circuit board 7 shown in FIG. 5 is shortened. Therefore, in this example, the length of the assembly in the endoscope radial direction (longitudinal direction in the drawing) can be shortened by the amount of both the air gap t3 and the thickness t4 of the circuit board 7, and the endoscope can be shortened. It is possible to contribute to the reduction of the diameter.

Further, according to the existence of the airtight space in the opening hole 21 of the circuit board 16, the color filter 1
As compared with the configuration of FIG. 5, light from the lens barrel portion 2 does not pass through the cover glass 4, and thus the condensing effect of the microlens 20 can be enhanced. There is.

Furthermore, the connection by wire bonding between the input / output terminal 22A of the wiring pattern 22 and the input / output terminal 24 on the CCD 18, which is made possible by providing the wiring hole 23, is advantageous in terms of cost. There is. That is, when the wiring hole 23 is not provided, a method of connecting using a bump device or the like can be considered. However, this is one in which one of the input / output terminals 22A and 24 is formed into a protruding shape and then both are directly contacted with each other. It is a method of crimping while applying heat, and special equipment is required for this purpose. On the other hand, in the case of wire bonding, existing equipment can be used and work efficiency is improved, which is advantageous in terms of cost.

Although the prism is used in the configuration of the above embodiment, the present invention can be applied to a type in which the image pickup element is arranged vertically to the objective optical system without using the prism. Further, the opening hole 21 of the circuit board 16 may have a shape other than a circular shape, and the shape and size are C
It can be appropriately set in the imageable area S of the CD 18.

Further, although the air gap portion is the opening hole 21 penetrating the circuit board in the above-mentioned embodiment, the opening is not such an opening hole, and a groove shallower than the thickness of the board is formed on the lower surface of the circuit board. Can also provide an air gap.

In the CCD 18, both the color filter 19 and the microlens 20 are provided. However, the present invention provides an image pickup device in which only the color filter 19 is formed and an image pickup device in which only the microlens 20 is formed. Also, the present invention can be similarly applied.

[0024]

As described above, according to the present invention,
An air gap portion (for example, an opening) for providing an air gap on the image pickup surface and a wiring pattern for connecting the image pickup element and the signal cable are formed on a circuit board, and this circuit board is used for the image pickup surface of the image pickup element and the objective. Since it is directly inserted in the optical system, the air gap can be efficiently arranged on the image pickup surface, the cover glass is not required, and the thickness of the conventional circuit board can be reduced. . Therefore,
There is an advantage that the length of the assembled body in the radial direction of the endoscope is shortened and the diameter of the endoscope can be reduced.

Further, since the circuit board is provided with the wiring hole, the terminals of the wiring pattern and the terminals of the image pickup device can be easily connected by wire bonding even if the circuit board and the image pickup device are arranged in an overlapping manner. Becomes Moreover, there is an advantage in that existing equipment can be used without requiring special equipment such as a bump device, which is advantageous in terms of cost.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of an image pickup element assembly of an electronic endoscope according to an example of an embodiment of the present invention.

FIG. 2 is a view showing a state where the assembled body of FIG. 1 is assembled.

FIG. 3 is an explanatory diagram showing a structure of a connection portion between the CCD and the circuit board of FIG.

4 is a diagram showing a state where the CCD and the circuit board of FIG. 1 are assembled.

FIG. 5 is a diagram showing a structure of a conventional image pickup element assembly.

FIG. 6 is a diagram showing an internal configuration of an endoscope using the assembly of FIG. 5 from the front side.

[Explanation of symbols]

 3,15 ... Prism, 4 ... Cover glass, 5 ... Package, 6,18 ... CCD, 7,16 ... Circuit board 19 ... Color filter, 20 ... Microlens, 21 ... Opening hole, 22 ... Wiring pattern, 22A, 24 ... I / O terminals, 23 ... Wiring holes.

Claims (1)

[Claims] 1. An image pickup device assembly for connecting an image pickup device having at least one of a color filter and a microlens formed on the image pickup face to an objective optical system, wherein the image pickup face of the image pickup device and the objective optical system are provided. In between, a circuit board having an air gap part for forming an image optical path and for providing an air gap on the imaging surface is arranged, and in order to connect the imaging element and the signal cable to the circuit board, A wiring pattern formed on the surface of the image pickup device on the side of the objective optical system that does not come into contact with the image pickup surface, and a wiring for connecting the terminals of the image pickup device to the terminals of the wiring pattern formed on the side of the objective optical system. An image pickup device assembly for an electronic endoscope, characterized in that a hole for use is formed.