JPH033361A - Hybrid integrated one-dimensional photoelectric transducer array - Google Patents

Abstract

PURPOSE:To obtain a low cost device realizing high performance by a simple constitution by a method wherein a grounding electrode having a part facing each optical signal output wiring with a desired facing area is arranged below an output terminal electrode connecting an optical signal output wiring part and a photoelectric transducer, via an interlayer insulating layer. CONSTITUTION:The following are mounted on a hybrid integration one-dimensional photoelectric transducer array: a plurality of photoelectric transducers 14 formed on an insulative substrate 11, a driving circuit 19 of the photoelectric transducers 14, and an optical signal output wiring part containing a plurality of optical signal output wirings 16 connecting the photoelectric transducers 14 with the driving circuit 19. In said array, grounding electrodes 25 are installed, which are formed below output terminal electrodes 23 connecting optical signal output wiring parts 16 and the photoelectric transducers 14, via an interlayer insulating layer 22, and have a part facing each optical signal wiring 16 with a desired facing area. For example, the area of the grounding electrode 25 below the facing electrode part 23 of the signal output wiring 16 of short wiring length is made large. On the contrary, the area of the grounding electrode 25 corresponding with the facing electrode of the signal output wiring 16 of long wiring length is made small. Thereby the earth capacity of each signal output wiring is uniformized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a hybrid integrated one-dimensional photoelectric conversion element array. More specifically, the present invention provides a novel configuration of a hybrid integrated one-dimensional photoelectric conversion element array suitable for close-contact reading in which light reflected from a document is received in a one-dimensional image sensor element array used for image reading. Regarding.

2. Description of the Related Art In the past, a one-dimensional photoelectric conversion element array such as a MOS or a CCD, called an IC sensor, was used as an image reading device for a document in a facsimile transmitter or the like. On the other hand, in recent years, so-called contact image sensors have been put into practical use, in which the document width corresponds to the photoelectric conversion element array width on a one-to-one basis. This type of image sensor does not require the optical path of the reduction optical system, and does not require the delicate adjustments that are inevitable when using the reduction optical system, so it greatly promotes the miniaturization and cost reduction of the transmitter. This makes it easy to use the reading device.

FIG. 3 is a diagram showing a typical configuration example of a photoelectric conversion element array used in the above-described contact type image sensor.

As shown in the figure, this photoelectric conversion element array is made of amorphous silicon (hereinafter referred to as a-Si) on a transparent glass substrate 1.
The photoconductive layer includes a common electrode 2 and individual electrodes 3 formed as a film formation pattern on a photoconductive layer, and a sensor element section 4. Usually, it includes a polyimide insulating layer coated on the surfaces of these components, an upper layer wiring conductor, a matrix wiring section 5, an output signal wiring section 6, and a drive IC arrangement section 7 formed on top of the polyimide insulating layer. .

The common electrode 2 and the individual electrodes 3 and the upper layer wiring are connected through through holes 8 provided in the polyimide insulating layer. Further, a drive IC 9 is fixed to the drive IC arrangement portion 7 with an adhesive, and the signal output line 6 and the drive IC 9 are connected through bonding wires 101.

The photoelectric conversion element array configured as described above receives image light at the sensor element section 4, and transmits a weak current between the individual electrodes 3 and the common electrode 2, which changes depending on the strength of the image light, to the output signal wiring section 6. The signal is amplified by the drive IC 9 and output as a scanning signal.

Problems to be Solved by the Invention The sensor element section 4 in the photoelectric conversion element array used in the contact type image sensor configured as described above has the same size as the width of the document to be read.

For example, in a sensor for reading an A4 size original, the width of the photoelectric conversion element array is 216+++ m.

Here, as can be seen from FIG. 3, the output signal wiring section 6 from the photoelectric conversion element section 4 to the drive IC 9 differs depending on the position of the corresponding sensor. That is, although it varies depending on the width dimension and pattern design of the transparent glass substrate 1,
The wiring length of the output signal wiring section 6 is from 1mm to 120I in the case of an A4 size photoelectric conversion element array! It varies within a range of about Ia+. Therefore, each input terminal of the drive IC 9 is connected to a wiring system having a different capacitance to ground. For this reason, the optical signal input to the drive IC 9 is contaminated with noise depending on the variation in ground capacitance, and the S/N ratio is degraded. This is particularly noticeable when reading a black original because the current value is small.

Such deterioration in characteristics due to variations in the wiring length of the output signal wiring section 6 can be corrected electrically, but in this case, an additional circuit is required and the equipment An increase in costs is inevitable.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art and provide a novel configuration of an inexpensive hybrid integrated one-dimensional photoelectric conversion element array that achieves high performance with a simple configuration.

Means for solving the problem, that is, according to the present invention, includes a plurality of photoelectric conversion elements formed on an insulating substrate, a drive circuit for the photoelectric conversion elements, and each of the photoelectric conversion elements is connected to the drive circuit. In a hybrid integrated one-dimensional photoelectric conversion element array equipped with an optical signal output wiring section including a plurality of optical signal output wirings, a terminal electrode is provided below an output terminal electrode that connects the optical signal output wiring section and the photoelectric conversion element, respectively. A hybrid integrated one-dimensional photoelectric conversion element array is provided, which is formed through an interlayer insulating layer and includes a ground electrode having a portion facing each optical signal output wiring with a desired facing area.

Here, according to a preferred embodiment of the present invention, the interlayer insulating layer interposed between the output terminal electrode and the ground electrode is an interlayer insulating layer on which IJ wiring is mounted, which constitutes the photoelectric conversion element. It is the same insulating layer as the layer.

Function The hybrid integrated one-dimensional photoelectric conversion element array according to the present invention has the following features:
Its main feature is that a ground electrode is placed below the output terminal electrode of the optical signal output wiring section via an interlayer insulating layer.

In the photoelectric conversion element array according to the present invention, since the ground electrode is provided below the optical signal output wiring section via the interlayer insulating layer, the capacitance between this ground electrode and each optical signal output wiring is appropriately set. By doing so, it is possible to adjust the capacitance to ground of each optical signal output wiring to correct variations in capacitance to ground between the optical signal output wirings.

That is, in contrast to the configuration of the conventional photoelectric conversion element array described above, the photoelectric conversion element array according to the present invention improves the S/N of the optical signal by equalizing the ground capacitance of the input terminal of the drive IC that reads the signal. are doing.

Hereinafter, the present invention will be described in more detail with reference to the drawings, but the following disclosure is only one embodiment of the present invention, and does not limit the technical scope of the present invention in any way.

Example 1 FIGS. 1(a) and 1(5) are a cross-sectional view and a plan view, respectively, showing a configuration example of a photoelectric conversion element array according to the present invention.

As shown in the figure, this photoelectric conversion element array consists of a transparent glass substrate 1 on which an a-3i photoconductor layer 20 is formed.
1, forming a first conductor layer consisting of a common electrode 12, individual electrodes 13 and ground wiring 21 formed on the a-3i photoconductor layer 20, and a photosensitive polyimide film 22 covering these first conductor layers. The second conductor layer further includes a matrix wiring section 15 formed on the polyimide film 22, a drive IC installation section 17, and a signal output wiring section 16. Through holes 18 are formed in the polyimide film 22 as necessary. Further, the drive IC 19 is mounted on the drive ICC installation part 7 and connected to each wiring by a bonding wire 30.

Here, in the vicinity of the connection point of each signal output wiring 16 with the common electrode 12 constituting the photoelectric conversion element, a counter electrode part 23 with a locally enlarged wiring width is provided, and it is connected to the ground electrode 25 through a polyimide film. They are facing each other.

The photoelectric conversion element array according to this embodiment with the above configuration has 8 elements/8 elements that can be used to read an A4 size document.
It is a ma+ photoelectric conversion element array, and the numbers of individual electrodes 13 and common electrodes 12 are 1728 and 1, respectively.
There are 08 pieces. Furthermore, the configuration of the matrix wiring section 15 is as follows:
The size is 108×16, and 108 signal output wirings 16 are arranged.

In a hybrid integrated one-dimensional photoelectric conversion element array having such a structure, the stray capacitance varies depending on the length of the wiring because each signal output wiring 16 is uneven due to the difference in distance to the drive IC 19. There is.

Now, for example, the width of the signal output wiring 160 is 0.1 mm,
Assuming that the length of the transparent glass substrate 11 is about 230 mm, each parasitic stray capacitance is in the range of about 0.1 pF to 5 pF.

Therefore, the counter electrode portion 2 of the signal output wiring 16 having a short wiring length is
The area of the ground electrode 25 under 3 is increased, and conversely, the ground electrode 2 corresponds to the counter electrode of the signal output wiring 16, which has a long wiring length.
By reducing the area of 5, the above-mentioned variations in stray capacitance can be corrected, and as a result, the ground capacitance of each signal output wiring is equalized.

Therefore, fixed pattern noise sources due to variations in capacitance to ground are eliminated, and the S/N ratio when reading image light is significantly improved. Furthermore, since a correction circuit is not required in the external signal processing circuit, this circuit can be connected at low cost.

Example 2 FIG. 2 is a plan view showing another example of the configuration of a photoelectric conversion element array according to the present invention.

As shown in the figure, this photoelectric conversion element array includes a matrix wiring section 35 formed on a transparent glass substrate 31;
It includes a photoelectric conversion element section 34, a ground wiring electrode section 41, and an output wiring terminal section 36. Moreover, this transparent glass substrate 31
The drive IC 2 mounted on the drive IC board 51 adjacent to
9, and a plurality of signal output wirings 56 of irregular lengths that connect the drive IC 29 and the photoelectric conversion element section 34 on the transparent substrate 31.

The transparent glass substrate 31 and the drive IC board 51 are arranged facing each other on a transparent support plate (not shown), and each output wiring terminal section 36 and the signal output wiring 56 are connected to the bonding wire 4.
Connected by 0. Note that a counter electrode section 55 is formed on the ground wiring electrode section 41 on the transparent glass substrate 31 to correct variations in stray capacitance of the signal output wiring section 56 of the drive IC board 51.

The hybrid integrated one-dimensional photoelectric conversion element array configured as described above functions in exactly the same way as the integrally configured photoelectric conversion element array shown in the first embodiment.
An inexpensive substrate material such as a printed board can be used for this purpose, while the width of the expensive transparent glass substrate 310 can be made small, making it possible to further reduce costs.

As described in detail of the invention, the hybrid integrated one-dimensional photoelectric conversion element array according to the present invention provides a counter electrode corresponding to the length of each signal output wiring and a ground wiring opposite to the counter electrode.
The capacitance to ground of the optical signal output wiring from each sensor is equalized by an equalization port to correct variations in parasitic capacitance due to uneven wiring lengths of the signal output wiring section. Therefore, it is possible to reduce noise contamination and improve photoelectric conversion characteristics without the need for additional circuits or complicated signal processing.

By using the photoelectric conversion element array according to the present invention, a high-performance contact sensor can be provided at a low cost, and by using it in a document reading device of a facsimile machine, it can be used in a low-cost, small-sized facsimile machine, etc. This makes it possible to manufacture image processing/communication devices.

[Brief explanation of drawings]

FIGS. 1(a) and 1(a) are a sectional view and a plan view, respectively, showing a configuration example of a photoelectric conversion element array according to the present invention, and FIG. FIG. 3 is a plan view showing a typical configuration of a conventional photoelectric conversion element array. [Main reference numbers] 1.11.31...Transparent glass substrate, 2.12...
...Common electrode, 3.13...Individual electrode, 4.14.34...Photoelectric conversion element section, 5.15.35
・ 6.16.56・ 7.17・ ・ ・ 8.18・ ・ ・ 9.19.29・ 10.30.40・ 20・ ・ ・ ・ ・ 21.41・ 22・ ・ ・ 23.36・ 25 .55・ 51・ ・ Matrix wiring section, signal output wiring section, drive IC installation section, through hole, bonding wire for connecting drive IC1, amorphous silicon (a-3i) semiconductor layer, ground wiring, polyimide insulating layer, counter electrode , ground electrode, drive IC board

Claims (1)

[Claims] an optical signal output wiring section including a plurality of photoelectric conversion elements formed on an insulating substrate, a drive circuit for the photoelectric conversion elements, and a plurality of optical signal output wirings respectively connecting the photoelectric conversion elements to the drive circuit; In a hybrid integrated one-dimensional photoelectric conversion element array equipped with 1. A hybrid integrated one-dimensional photoelectric conversion element array comprising: a ground electrode having portions facing each other with a desired facing area;