JPH02122577A - Reader - Google Patents

Abstract

PURPOSE:To obtain a highly reliable reader which is superior in quality and facilitates manufacturing control by forming a photoelectric conversion layer and an electrode layer one by one on a substrate for loading photoelectric conversion elements and forming wire bonding pad parts after performing wiring to a part of the above electrode layers from a substrate side for loading signal processing circuits. CONSTITUTION:A Cr layer 20 and an Al layer 21 are formed one by one to a part of the plate face of a glass substrate 12 and a common electrode is composed of the above two layers 20 and 21. An amorphous silicon photoelectric conversion layer 22 is formed so that its layer 22 covers two layers 20 and 21 and it extends over almost all the area of the substrate 12. Then an ITO layer 23, a Cr layer 24, and an Al layer 25 are laminated one after another on the layer 22; besides, they are formed separately into each electrode having a required form by etching. Further, optical passing holes 26 are formed with each element in the Cr layer 20, the photoelectric conversion layer 22, and the ITO layer 23. Then two kinds of leads 27 are connected from an IC chip 15; one of the leads 27 is connected to an end part of the Al layer 25 and its connecting place is formed into a wire bonding pad 28.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reading device such as a contact type image sensor.

[Prior art and its problems]

A contact image sensor has already been put into practical use, and according to the reading system of that sensor, the size of the image sensor is substantially 1:1 with respect to the original.
A long reading device corresponding to the above is brought into close contact with the document, and a light source disposed in the device projects light onto the document, receives the reflected light, and photoelectrically converts it to obtain a read signal.

This reading device reads the document in its long horizontal direction (main scanning direction) and simultaneously moves the document perpendicular to the main scanning direction (
The direction of movement is called the sub-scanning direction), thereby
It is possible to read two-dimensional images of manuscripts.

FIG. 4 is a cross-sectional view in the sub-scanning direction of an already proposed reading device. According to the figure, 1 is a glass substrate, and a common electrode 2 made of AI, Cr, etc. is formed on this substrate 1. A photoelectric conversion layer 3 made of amorphous silicon or the like is formed on the common electrode 2, and a transparent conductive layer 4 and a metal layer 5 made of An, Cr, etc. are sequentially formed on the photoelectric conversion N3. Layers 4 and 5 serve as individual electrodes for each element.

The common electrode 2, the photoelectric conversion layer 3, and the transparent conductive layer 4 have a common light passage hole 6 formed therein, and these light passage holes 6 are also formed in one-to-one correspondence for each element.

Further, one end of the transparent conductive layer 4 and the metal layer 5 extends close to the element selection IC chip 7, and the end portion is a wire bonding pad 8.

Two types of glue portions 9 are connected from the IC chip 7, one lead is connected to the pad 8, and the other lead is connected to the signal derivation pad 10. The signal deriving bat 10 is formed by laminating a transparent conductive layer and a metal layer, and is formed at the same time as the individual electrodes are formed.

In the reading device having the above configuration, a document (not shown) is placed on the element forming side of the substrate 1, a light source (not shown) is placed on the opposite side, and the light emitted by the light source passes through the light passage hole 6. Light is projected onto the original, and the reflected light is received by the photoconductive conversion layer 3 through the transparent conductive layer 4, and a read signal is derived from the individual electrodes. Further, the IC chip 7 is made up of analog switches, shift registers, and the like, so that read signals can be selected for each element.

However, in the reading device having the above configuration, when the photoelectric conversion layer 3 is formed of a thin film such as amorphous silicon, it is necessary to perform masking using a metal mask or the like to form the required portions of the plate surface of the substrate 1. This increases the number of manufacturing steps. Moreover, when performing this masking, care must be taken to ensure that the thin film component does not enter into areas where the thin film is not formed on the plate surface of the substrate l.
Manufacturing management for this becomes complicated.

Furthermore, if the thin film-free area becomes contaminated, there is a problem in that the metal layer 5 formed thereon is discontinuous, or short circuits occur between the individual metal layers 5 or between the individual transparent electrode layers 4. be.

In addition, the individual electrodes are formed continuously on the photoelectric conversion layer 3 and the glass substrate l, so that the boundary between the two 13 becomes a step 11, which may cause disconnection of the individual electrodes.
Another problem is that short circuits occur between individual electrodes.

Therefore, the present invention has been devised in view of the above,
The purpose is to provide a high-quality and highly reliable reading device that eliminates disconnections and short circuits and facilitates manufacturing control.

[Means for solving problems]

The reading device of the present invention includes a base, a photoelectric conversion element mounting board disposed on the base, and a signal processing circuit mounting board disposed on the base and in parallel with the substrate, and , a photoelectric conversion layer and an electrode layer are sequentially formed on a substrate for mounting a photoelectric conversion element, and a part of this electrode layer is a wire bonding pad portion formed by wiring from the side of the substrate for mounting a signal processing circuit. do.

〔Example〕

Hereinafter, the present invention will be explained in detail using the reading device shown in FIGS. 1 to 3.

FIG. 1 is a cross-sectional view of the reading device in the sub-scanning direction;
The figure is an enlarged view of the main part, and FIG. 3 is a perspective view of the main part of the reading device.

In FIG. 1, 12 is a glass substrate, 13 is a photoelectric conversion element array formed on the substrate 12, and 14 is a printed circuit board. A flat package and chip components (not shown) comprising a signal processing circuit are mounted. The element selection IC chip 15 is made up of analog switches, shift registers, etc., and allows read signals to be selected for each element.

Further, the signal processing circuit consists of an amplifier circuit, a signal correction circuit, a reference circuit, etc., and the read signal is processed by the signal processing circuit (i)...1.0 to 2. Amplified to OV (
ii) ... Image information with uniform sensitivity is output by correcting the output variations of each element (iii) ... A signal that outputs the reference level necessary for A-D conversion of the image information, etc. Processing takes place.

The glass substrate 12 and printed circuit board 14 are placed on a metal substrate support member 16, and this substrate support member 1
6 is attached with a light source 17 consisting of an LED or the like,
This light source 17 passes through the glass substrate 12 and illuminates the original 18.

Note that 19 is a connector for leading out the read signal output from the signal processing circuit to the outside.

FIG. 2 specifically shows the configuration of the photoelectric conversion element array 13. According to the figure, a 01 layer 20 and a 41 layer 2I are sequentially formed on a part of the plate surface of a glass substrate 12, and both layers 20 and 21 form a common electrode. Then, an amorphous silicon photoelectric conversion layer 22 is formed by a glow discharge decomposition method so as to cover both layers 20 and 21 and over almost the entire substrate 12, and an ITO layer 23 and a Cr layer are further formed on the photoelectric conversion layer 22. 24
and AI layers 25 are sequentially laminated and etched to form individual electrodes in a desired shape. Furthermore, light passage holes 26 are formed in the 01 layer 20, the photoelectric conversion layer 22, and the ITO layer 23 for each individual element.

Thus, the photoelectric conversion element array 13 of this example is as shown in FIG.

Further, two types of glue portions 27 are connected from the IC chip 15, one of the glue portions 27 is connected to the end of the 41st layer 25, and the connection point becomes a wire bonding pad 28.

According to the reading device having the above configuration, the photoelectric conversion N22 is formed on the 01 layer 20, so that the Cr layer 24 and the AI
The level difference in Ji25 is significantly reduced, and the occurrence of disconnection or short circuit of individual electrodes can be prevented.

Moreover, the amorphous silicon photoelectric conversion layer 22 can be formed over the entire surface of the glass substrate, and no masking is required.

〔Effect of the invention〕

As described above, according to the reading device of the present invention, a photoelectric conversion layer can be formed without using masking, thereby reducing the number of steps, making manufacturing management easier, increasing manufacturing efficiency, and resulting in lower manufacturing costs. This results in a reduction in

Further, according to the reading device of the present invention, a photoelectric conversion layer can be formed over the entire plate surface, and an electrode layer can be formed on the photoelectric conversion layer without any contamination source, and the level difference can be significantly reduced. As a result, there is no disconnection or short circuit in the electrode layer, and as a result, a high quality and highly reliable reading device can be provided.

Note that the reading device of the present invention is not limited to the above-mentioned embodiments, and may use a charge conversion layer made of other materials such as CdS, or may make structural changes or improvements without departing from the gist of the present invention. There is no problem.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a reading device according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of essential parts of the reading device, FIG. 3 is a perspective view showing the photoelectric conversion element array of the reading device, and FIG. FIG. 1 is a cross-sectional view of a conventional reading device. 12・ 13・ 15・ 22・ 23・ 24・ 25・ 28・ Glass substrate photoelectric conversion element array element selection IC chip amorphous silicon photoconductive layer ITO @ 1 layer wire bonding pad part to Cr layer Patent applicant (663) Kyocera Co., Ltd. Representative Kinju Anjo

Claims (2)

[Claims] (1) A reading device comprising a base, a photoelectric conversion element mounting board placed on the base, and a signal processing circuit mounting board placed on the base and in parallel with the board, A photoelectric conversion layer and an electrode layer are sequentially formed on the photoelectric conversion element mounting substrate, and a part of the electrode layer is a wire bonding pad portion formed by wiring from the signal processing circuit mounting substrate side. A reading device. (2) The reading device according to claim (1), wherein the photoelectric conversion layer is an amorphous silicon layer.