JPH06121113A - Image sensor - Google Patents

Abstract

PURPOSE:To prevent an output from being defective by dust such as a glass fiber generated from a substrate. CONSTITUTION:A glass cover 2 is fitted to the upper part of a frame 1, a light source substrate 4 mounting a light emitting element 3 is fixed inside the frame 1, and a rod lens array 5 is fixed. A sensor substrate 7 mounting a light receiving element 6 is arranged at the lower part of the frame 1, and positioning holes 7a and 7b are bored on the both sides of the sensor substrate 7 in the lengthwise direction. Pins 1a and 1b are provided projectingly at the lower part of the frame 1 corresponding to these holes 7a and 7b and further, the holes 7a and 7b are coated with friction reducing films for preventing friction with the pins 1a and 1b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor used in facsimiles, optical character readers and the like.

[0002]

2. Description of the Related Art An example of a conventional image sensor is shown in FIG. In this image sensor, a transparent cover (glass cover) 31 that abuts an imaging target on the upper portion of the frame 30.
The light source substrate 33 on which the light emitting element 32, which is a light emitting portion, is mounted is fixed to the frame 30 at an angle of about 45 degrees with respect to the surface of the glass cover 31. Also, the light emitting element 3
A spherical plastic lens 34 is arranged on the optical path of 2, and a rod lens array 35, which is an optical system for condensing the reflected light from the document W which is the imaging target on the glass cover 31, is provided on the glass cover 31. Is fixed to the frame 30 perpendicularly to the plane. Further, below the frame 30, there is provided a sensor substrate 37 on which a light receiving element 36 serving as a light receiving portion is mounted. Further, in this image sensor, the elastic member 38 is fixed on the sensor substrate 37, and the sensor substrate 37 is pressed against the bottom surface 30a of the frame 30 and positioned by the elastic member 38.

By the way, in the sensor substrate 37 provided with the light receiving element 36, in addition to through holes for wiring the electronic components such as the light receiving element 36, pins of parts such as connectors for external connection are fitted and parts are attached. In many cases, a positioning hole for positioning is formed. Next, a manufacturing process of a substrate having a through hole and a positioning hole will be briefly described with reference to FIGS. 6 and 7. First, the prepared hole 41 of the through hole is formed in the base material 40 as shown in FIG. 6A (see FIG. 6B). Subsequently, copper plating 42 is applied to the front surface and the back surface of the base material 40 including the wall surface of the prepared hole 41 [see (c) of FIG. 6]. Then, after etching the copper plating 42 according to a predetermined wiring pattern [see (d) of FIG. 7],
The necessary wiring patterns are left and the other wiring patterns are covered with the resist 43 [see (e) of FIG. 7]. Finally, a positioning hole 44 into which a pin of a component such as a connector is fitted
To form a base substrate [see (f) in FIG. 7].

Electronic components such as a light receiving element and a connector are mounted at predetermined positions on the completed base substrate. For example, as shown in FIGS. 8 and 9, when light receiving elements (bare chips) 51 are mounted in an array on the front surface side of a base substrate (sensor substrate) 50 and a connector 52 is mounted on the rear rear side, the projections are provided on the connector 52. Pin 52a, 5
2b to the positioning holes 50a, 50 formed in the substrate 50.
The connector 52 is positioned on the board 50 by being fitted into the connector b.

[0005]

By the way, as shown in the enlarged sectional view of the positioning hole 50a (50b) of the substrate 50 in FIG. 10, the substrate 50 is usually made of glass epoxy, and in this case, the positioning hole is formed. The glass fiber 60 projects from the wall surface of 50a (50b). When the pins 52a and 52b of the connector 52 are fitted into the positioning holes 50a and 50b in such a state, the pins rub against the wall surface of the hole, and the glass fiber 60 protruding from the wall surface is torn,
Appears on the substrate 50 (see FIG. 9). This glass fiber 60
Is likely to adhere to the light receiving element 51, and the light that should be received by the light receiving element 51 is blocked or weakened by the glass fiber 60, resulting in frequent output failures of the image sensor.

Therefore, it is an object of the present invention to provide an image sensor which prevents output failure due to dust such as glass fibers generated from a substrate.

[0007]

In order to achieve the above object, in the image sensor of the present invention, a transparent cover for abutting an object to be imaged is attached to a frame, and in the frame,
A light emitting unit for irradiating the imaged object with light, an optical system for collecting reflected light from the imaged object, and a substrate provided with a light receiving unit for receiving light from the optical system are provided. In an image sensor having a hole for inserting a pin of another component in the substrate, the hole is provided with an anti-friction film for preventing abrasion of the hole and the pin of the other component. To do.

In this image sensor, since the wall surface of the hole is covered with the anti-friction film, the pin and the hole are not worn even when the pins of other parts are fitted into the hole, and dust (glass fiber) generated from the substrate is generated. Etc.) does not appear on the substrate. Therefore, the output of the image sensor is stable. In the image sensor of the present invention, the holes of the substrate and the pins of the other parts can have various modes. For example, in the image sensor according to claim 2, as described above, the hole of the board is a positioning hole for attaching a connector for connecting the board to the outside, and the pins of other parts are the positioning holes of the board. Corresponding pins provided on the connector.

Other than this, there are various modes as holes and pins. Particularly, in the image sensor according to claim 3, the hole of the board is a positioning hole of the board itself, and the pins of the other parts are pins provided in the board mounting portion of the frame corresponding to the positioning hole of the board. . This image sensor relates to the image sensor previously filed by the applicant,
The board can be positioned on the frame simply by inserting the pins of the frame into the positioning holes of the board. Particularly, by forming one positioning hole and the pin with high precision, there is an advantage that the substrate can be accurately attached in the transverse direction and the longitudinal direction of the frame.

The anti-friction film to be applied to the hole is not limited in its material as long as it can prevent abrasion of the pin of another component when it is fitted, and the nickel used in ordinary through holes is used. Examples of plating include copper plating and gold plating.

[0011]

EXAMPLES The image sensor of the present invention will be described below based on examples. FIG. 1 shows a partially cutaway side view of one embodiment. This image sensor is based on the prior application of the present applicant, in which a positioning hole of the substrate itself is formed in a substrate provided with a light receiving portion, and a pin is protrudingly provided in a substrate mounting portion of a frame corresponding to the positioning hole of the substrate. ing.

A transparent cover (glass cover) 2 is attached to the upper part of the frame 1, and a light source substrate 4 on which light emitting elements (LED chips, etc.) 3 are mounted in an array in the frame 1.
Is fixed at an angle of about 45 degrees with respect to the surface of the glass cover 2, and is a rod lens array 5 which is an optical system for condensing reflected light from a document (not shown) on the glass cover 2. Are fixed perpendicularly to the surface of the glass cover 2. Directly below the rod lens array 5 is a sensor substrate 7 on which light receiving elements (photodiodes or the like) 6 for receiving light from the array 5 are mounted in an array.

The sensor substrate 7 is pushed upward by a stopper plate 8 provided on the bottom of the frame 1 through a reinforcing plate 9 and then fixed to the lower portion of the frame 1.
The stopper 8 is not provided over the entire length of the image sensor, but is engaged with the protrusions 1c and 1d formed on the side portion of the frame 1 on both sides of the image sensor in the longitudinal direction.

As shown in the schematic plan view of FIG. 2, the sensor substrate 7 is provided with positioning holes 7a and 7b at both ends in the longitudinal direction. Here, the positioning hole 7a has an oblong shape (stupid hole), and the positioning hole 7b serves as a reference hole. The anti-friction film, which is a feature of the present invention, is provided so as to cover the wall surfaces of the holes 7a and 7b, which is not particularly shown in FIG. The details of the anti-friction film will be described later in the substrate manufacturing process.

On the other hand, on the lower part of the frame 1, pins 1a and 1b corresponding to the positioning holes 7a and 7b of the sensor substrate 7 are provided.
(Only the pin 1b is shown in FIG. 1) is provided in a protruding manner, the pin 1a is inserted into the fool hole 7a, and the pin 1b is a reference pin and is inserted into the reference hole 7b. The pins 1a and 1b can be manufactured, for example, by molding the frame 1 by injection molding of resin,
It can be formed integrally with the frame 1.

In this image sensor, by inserting the pins 1a and 1b of the frame 1 into the holes 7a and 7b of the sensor substrate 7, the substrate 7 can be positioned on the frame 1. In particular, by fitting the reference pin 1b into the reference hole 7b, the substrate 7 can be attached to the frame 1 with high accuracy. The image pickup operation of this image sensor is similar to the conventional one, the light emitted from the light emitting element 3 is incident on the original on the glass cover 2, and the reflected light from the original is condensed by the rod lens array 5. The light is received by the light receiving element 6 and converted into an electric signal.

Next, the fabrication of the sensor substrate 7 in the image sensor as described above will be briefly described with reference to the steps shown in FIGS. First, the prepared holes 11 and the positioning holes 12 of all through holes are drilled at predetermined positions of the base material 10 as shown in FIG. 3A (FIG. 3B).
reference〕. Then, copper plating 13 is applied to the prepared hole 11 of the through hole, the wall surface of the positioning hole 12, and the front and back surfaces of the base material 10 [see (c) of FIG. 3]. Then copper plating 1
3 was etched according to a predetermined wiring pattern [Fig.
(D)] after that, the necessary wiring pattern of the copper plating 13 is exposed, and the other wiring patterns are formed in the resist 1
By coating with 4, the base substrate is completed [Fig.
(E)].

According to this process, the positioning hole 12 is first opened together with the prepared hole 11 of the through hole as compared with the conventional process shown in FIGS. 6 and 7, so that the final positioning hole drilling process [FIG. (See (f)] is unnecessary, and the base substrate is finished by applying a resist. That is, since the positioning hole 12 is simultaneously formed as a dummy through hole together with the original through hole 11 for electrically connecting the electronic component such as the light receiving element, not only the through hole 11 but also the positioning hole 12 is formed. , Copper plating (conductive metal film) 1
3 is present, and copper plating 13 'is applied to the positioning hole 12
Is the anti-friction film. Since the wall surface of the positioning hole 12 is covered with the anti-friction film 13 ′, the glass fiber of the base substrate material (glass epoxy) does not appear from the wall surface of the positioning hole 12. Therefore, even if the pin of the frame is fitted into the positioning hole 12, the glass fiber does not accumulate on the base substrate 10 due to the friction between the pin and the positioning hole 12, and the output failure of the image sensor is eliminated.

In the above embodiment, the sensor substrate 7 is provided with its own positioning holes 7a and 7b, and the frame 1 is provided with the pins 1a and 7b.
Although a and 1b are provided (according to the prior application of the applicant), even if a positioning hole for an electronic component such as a connector is formed on the sensor substrate and the electronic component is provided with a pin,
An equivalent effect can be obtained.

[0020]

As described above, in the image sensor of the present invention, the hole formed in the substrate having the light receiving portion is provided with the anti-friction film for preventing the hole and the pin of the other component from being worn.
It has the following effects. (1) Since the board material (glass epoxy) is not exposed from the wall surface of the hole, dust such as glass fiber generated from the board does not appear on the board even when the pins of other parts are fitted into the hole, and the dust is generated. Output failure does not occur. (2) Since holes can be formed at the same time as through holes in the substrate manufacturing process, the manufacturing process can be simplified. (3) Since it is not necessary to remove dust such as glass fiber when assembling the image sensor, the image sensor assembling process can be simplified.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of an image sensor according to an embodiment of the present invention.

FIG. 2 is a schematic plan view of a sensor substrate incorporated in the image sensor shown in FIG.

FIG. 3 is a manufacturing process diagram of a sensor substrate incorporated in an image sensor.

FIG. 4 is a manufacturing process diagram following FIG. 3;

FIG. 5 is a cross-sectional view of a main part of an image sensor according to a conventional example.

FIG. 6 is a manufacturing process diagram of a sensor substrate incorporated in an image sensor.

FIG. 7 is a manufacturing process diagram following FIG. 6;

FIG. 8 is a partial perspective view showing a state where a connector is attached to a sensor substrate incorporated in an image sensor.

FIG. 9 is a partial perspective view showing a state in which a connector is attached to a sensor substrate incorporated in an image sensor.

FIG. 10 is a partially enlarged view for explaining the state of the positioning hole after the sensor substrate is manufactured.

[Explanation of symbols]

1 frame 2 glass cover (transparent cover) 3 light emitting element 5 rod lens array (optical system) 6 light receiving element 7 sensor substrate 1a, 1b frame pins (pins, reference pins) 7a, 7b positioning holes for the sensor substrate (dumb hole, Reference hole) 10 Base substrate (sensor substrate) 12 Positioning hole 13 'Copper plating (anti-friction film)

Claims (3)

[Claims] 1. A transparent cover for contacting an object to be imaged is attached to a frame, and a light emitting portion for irradiating the object to be imaged with light and a light reflected from the object to be imaged are condensed in the frame. Of the optical system, and a substrate provided with a light receiving portion for receiving light from the optical system, the image sensor formed by forming a hole for inserting a pin of another component in the substrate, the hole An image sensor characterized in that an anti-friction film is applied to the hole to prevent abrasion of the hole and the pin of other parts. 2. The hole is a positioning hole for mounting a connector for connecting the board to the outside, and the pin of the other component is a pin provided in the connector corresponding to the positioning hole of the board. The image sensor according to claim 1, wherein the image sensor is provided. 3. The hole is a positioning hole of the substrate itself,
The image sensor according to claim 1, wherein the pin of the other component is a pin provided on a board mounting portion of the frame corresponding to a positioning hole of the board.