JPS6346985B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a one-dimensional image sensor, and particularly to a one-dimensional image sensor suitable for scanning an image of a document at a reduction ratio of equal to or close to equal magnification.

Conventionally, in this type of image sensor,
The integrated circuit (IC) chip that should be connected to the electrode of the photodetector is not placed on the same substrate as the electrode.
Therefore, the overall size of the sensor was large, and the connection between the IC chip and the electrodes was made using wire bonding, which resulted in problems such as low work efficiency in image sensor manufacturing and low product reliability. .

An object of the present invention is to provide a one-dimensional image sensor that is small, highly reliable, and easy to manufacture.

In the one-dimensional image sensor according to the present invention, a plurality of diodes are formed in a stripe shape with their common electrodes connected on a transparent part of a partially or completely transparent substrate, and a counter electrode of the diodes is formed on a transparent part of a partially or completely transparent substrate. divided into a plurality of groups consisting of a predetermined number of counter electrodes adjacent to each other, and providing a driving integrated circuit chip for each group of mutually adjacent counter electrodes on opposite sides of the stripe on the substrate; It is characterized in that each of the tapes extends toward the integrated circuit chip to be connected, and is connected to the integrated circuit chip using a tape carrier.

FIG. 1 shows an embodiment of a one-dimensional image sensor according to the present invention, and FIG. 2 shows a cross section of the portion indicated by a chain line. In the same figure, 1
is a band-shaped substrate, and is composed of a central member 1a occupying the center portion in the width direction, and side plates 1b and 1c joined to both sides of the central plate 1a. The central plate 1a is made of a transparent material, for example glass. The side plates 1b and 1c are made of, for example, glass epoxy resin. A reinforcing plate 2 has the same planar shape as the substrate 1 and is made of, for example, glass epoxy resin. As shown in FIG. 2 and FIG. 3 depicting the bottom surface, the reinforcing plate 2 is provided with a slit-shaped optical window 2a extending vertically from the center of the reinforcing plate 2 in the width direction.

3 is a photodiode array, on the substrate 1,
Directly above the light window 2a, it extends in a stripe shape along the light window 2a. The photodiode array 3 comprises a transparent common electrode 4 fixed on the substrate 1 as shown in FIG. 2, a photoconductive material layer 5 disposed on the common electrode 4, and a photoconductive a separate counter electrode 6 provided on top of a layer 5 of a magnetic substance.

The common electrode 4 is made of SnO ₂ , for example.

The photoconductive material layer includes a CdS layer 5a, a CdTe layer 3b,
and As ₂ Se _three layers 3c. The photoconductive material layer 5 can also be formed of an amorphous achalcogenide material instead of that shown in FIG.

The counter electrodes 6 are arranged in a group G ₁ , every 32 counter electrodes, for example.
G ₂ , G ₃ . . . and the counter electrodes 6 of each group extend close to the sides of the center plate on the same side with respect to the stripes of the photodiode array. For example, the counter electrode belonging to group _G2 extends to the right in FIG. Also, the counter electrodes 6 of each group, for example those belonging to group G ₂ , are connected to adjacent groups, for example G ₁ and G ₂
The counter electrodes belonging to the photodiode array extend on opposite sides with respect to the stripe 3 of the photodiode array. The counter electrode 6 is made of Au, for example, but when using the vapor deposition method, since the adhesion strength of Au to glass is weak, the extension portion 6a is made of Au.
A Cr layer 6b is interposed between the glass plate and the glass plate.

11 is an IC chip, one for each group of counter electrodes.
They are provided one by one. The IC chips 11 are arranged on the side where the corresponding group of counter electrodes extend as shown. In other words, they are set up in correspondence with adjacent groups.
The IC chips are located on opposite sides of stripe 3. As shown in FIG. 5, the IC chip 11 includes 32 MOS switches MS each connected to a photodiode PD, and a 32-bit shift register SR that controls opening and closing of the MOS switches MS. The shift register SR is started by the start pulse Vs, and the clock pulse
Each time Vc is received, MOS switch MS is made conductive in order. Each photodiode has a connected MOS
Charges are accumulated according to the amount of light received while the switch is not conducting, and the accumulated charges are output from the output terminal OUT when the connected MOS switch is conducting.

The IC chips 11 are each preliminarily bonded to a tape carrier 12 by inner lead bonding, and one end of the conductive wire of the tape carrier is connected to the center plate 1.
The outer lead is bonded to the extended end of the individual electrode of the photodiode array on a.

An input/output line 13 extending in the vertical direction is provided on the outer side portions of the side plates 1b and 1c, and the other end of the conducting wire of the tape carrier 12 is outer lead bonded to the input/output line 13. Input/output line 13
A terminal group 14 is formed at the end of the terminal. A ground line 15 also extends from this terminal group 14. This ground line is connected to the common electrode 4 of each photodiode, and is the only point where the common electrode is drawn out to the outside.

The upper surface of the substrate 1 on which the photodiode array 3 and IC chip 11 are mounted is covered with a cover 21.

During manufacturing, a photodiode array was installed on the center plate 1a and a tape carrier was connected.
After the IC chips are provided on the side plates 1b and 1c, the center plate 1a is joined to the reinforcing plate 2, and then the side plates 1b and 1 are bonded to the reinforcing plate 2 and the center plate 1a.
c, and bond the conductive wire of the tape carrier to the extended end of the counter electrode. In this way, the installation of the photodiode array on the center plate 1a,
After installation of the ICs on the side plates 1b and 1c, each assembly can be inspected. Therefore, yield can be improved.

Incidentally, as shown in FIG. 7, the arrangement of the electrodes may be reversed. That is, the common electrode 4 made of Au is the top layer, the counter electrode 6 made of SnO ₂ is the bottom layer, and the photoconductive material layer 5 is interposed between them. Then, the extension portion 6a made of Au and the intervening layer 6b made of Cr are connected to the counter electrode 6. The connection polarity of the photodiode in FIG. 5 is reversed.

Since the extensions of the counter electrodes in adjacent groups are located on opposite sides, the distance between the extensions 6c can be increased, as shown in FIG. 6.
Therefore, bonding of the tape carrier is easy. Furthermore, since the IC chip is mounted on the same substrate as the photodiode array, the image sensor as a whole becomes smaller. moreover,
If the conductive wire of the tape carrier of the IC chip is bonded to the extended end of the counter electrode as in the illustrated embodiment, the reliability of the bonding portion will be increased.

Further, according to the present invention, it is easy to form a common electrode and a space can be provided between electrode groups, which makes inspection easier and improves yield.Furthermore, the integrated circuit can be placed close to the photodiode array using a tape carrier. Since it can be arranged in a straight line, parasitic capacitance is reduced and high drive speed can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the image sensor according to the present invention, FIG. 2 is an enlarged sectional view taken along the line - - in FIG. 1, and FIG. 3 is a bottom view of the image sensor in FIG. Figure 4 is a schematic diagram showing the extension direction of the counter electrode, Figure 5 is a wiring diagram showing the electrical connection between the IC chip and the photodiode array, Figure 6 is a schematic diagram showing the extension of the counter electrode, and Figure 6 is a schematic diagram showing the extension of the counter electrode. 7
The figure is a sectional view showing a modification of the arrangement of electrodes. DESCRIPTION OF SYMBOLS 1...Substrate, 1a...Central plate, 3...Striped photodiode array, 4...Transparent electrode, 5...Photoconductive material layer, 6...Counter electrode, 6a
...Extension of counter electrode, 11...IC chip, 12
... Tape carrier, G ₁ , G ₂ , G ₃ ... Group of counter electrodes.

Claims (1)

[Claims] 1 A plurality of diodes are formed in a stripe shape with their common electrodes connected on a transparent part of a partially or completely transparent substrate, and the counter electrodes of the diodes are composed of a predetermined number of counter electrodes adjacent to each other. dividing into a plurality of groups, and providing driving integrated circuit chips for each of the mutually adjacent counter electrode groups on opposite sides of the stripes on the substrate, and directing the counter electrodes toward the integrated circuit chips to which they are respectively connected. A one-dimensional image sensor, characterized in that the one-dimensional image sensor is stretched and connected to the integrated circuit chip using a tape carrier.