JPH01282864A - Manufacture of matrix wiring section of image sensor - Google Patents

Abstract

PURPOSE:To reduce the wiring resistance of output electrodes and also to make a sensor smaller by film-forming a wiring pattern of output electrodes, and then by plating the wiring pattern electrolytically using the pattern as the negative electrode, and forming a plating film on the pattern. CONSTITUTION:Photoconductive films of CdS-CdSe, etc., are formed on a substrate 1 through evaporation, etc., and they are formed into photodetectors 2 through photoetching, etc. After that, they are heat-treated and given photoelectric transducing characteristics. Then, NiCr-Au, etc., are formed into a pattern on the substrate 1 through lift off, etc., to make common electrodes 3 and individual electrodes 4. Next, intermediate layer insulating films 6 are formed in a specified pattern. Then, NiCr-Au, etc., are formed into a pattern to get output electrodes 7 on them. After that, the output electrodes 7 are electrolytically plated and a film of Au, etc., is formed through the plating. This plating film reduces the wiring resisting of the output electrodes 7 greatly.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an image sensor used in an image reading section of a facsimile machine, etc., and particularly relates to a method for manufacturing a multi-IJ Fuchs line section on a sensor substrate. .

A typical wiring layout structure of a conventional technology-based image sensor is shown in Figure 2 (for example, [Nikkei Mechanical J 19
(See December 1, 1986 issue, pages 71-78).

As shown in FIG. 2, a large number of light receiving elements 2 are formed on a substrate 1 in a linear arrangement, and a wiring pattern consisting of a common electrode 3 and individual electrodes 4 is formed. In this example, six light receiving elements 2 are made into one group, and each group has the same wiring pattern. That is, on one side of the two rows of light receiving elements, one end of each of the six light receiving elements 2 is connected to one common electrode 3, and the other end of each light receiving element 2 is connected to an individual electrode 4, respectively. The common electrode 3 is connected to a butt portion 3a provided at one end of the substrate 1. In addition, the individual electrodes 4 are arranged in a matrix wiring part 5 in a pattern of 6 pieces.
connected to.

This matrix wiring section 5 is the part targeted by the present invention. The individual electrodes 4 in the matrix wiring section 5 are the lower layer wiring pattern, on which the pattern of the intermediate layer insulating film 6 is formed, and further on this, the six parallel output electrodes 7 which are the upper layer wiring pattern are formed. has been done. The output electrode 7 is connected to the lower layer individual electrode 4 at the contact portion 8 where the intermediate layer insulating film 6 is not provided.

Problems to be solved by the invention In the case of contact type image sensors for facsimile machines, etc.
The number of arrays of light receiving elements 2 is very large, and the sensor substrate 1 becomes long. Since the wiring pattern of the output electrode 7 is formed over the entire length of the substrate 1, the wiring length becomes very long if it is long. In addition, due to the demand for miniaturization of equipment, the sensor board 1
Since the width of the output electrode 7 is designed to be as small as possible, the width of each line and the pitch between the lines of the output electrode 7 must also be made small.

Usually, the wiring pattern of the matrix wiring section 5 is made using thin film technology such as vapor deposition or lift-off method. With thin film technology, the electrode film thickness cannot be made very large, so in a long image sensor, the output electrode 7 is thin and long. In this case, even if a metal material with a low specific resistance is used, the wiring resistance of the output electrode 7 increases.

In a device such as an image sensor that uses a slight change in a minute current as information, the presence of wiring resistance of the output electrode 7 has a large adverse effect on sensor performance.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to improve the conductivity of the output electrode by a simple method and to suppress wiring resistance even if the output electrode becomes long. It's about doing.

Means to Solve the Problem Therefore, in the present invention, the wiring pattern of the output electrode in the matrix wiring part is formed into a thin film by a lift-off method or the like, and then electrolytic plating is performed using the wiring pattern as a negative electrode to form a thin film made of a predetermined conductive material. A plating film was formed.

According to a thin film technique such as a functional lift-off method, a fine wiring pattern of the output electrode can be formed easily and with high precision. However, as mentioned above, the film thickness cannot be made very large. By applying electrolytic plating to this wiring pattern, the conductivity of the output electrode is improved by the plating film, and the wiring resistance is reduced.

Embodiment FIG. 1 shows a wiring layout structure in the process of being manufactured in an embodiment of the present invention. First, Cd5-C on the substrate 1.
A photoconductive film such as dSe is formed by vapor deposition or the like, and then formed into the shape of the light receiving element 2 by photoetching or the like. Then Cd
It is photoelectrically activated by heat treatment at 450C to 600C in vapor such as C-e2 and imparts photoelectric conversion characteristics.

Next, NtCr Au etc. is removed from the substrate 1 by lift-off etc.
A pattern is formed on the top to form a common electrode 3 and individual electrodes 4. Next, an intermediate insulating film 6 made of polyimide resin or the like is placed on the individual electrodes 4 that constitute the matrix wiring section 5.
is coated in a predetermined pattern. Then on top of these
Patterning iCr-Au etc. by lift-off etc.
An output electrode 7 is obtained. This output electrode 7 is connected to the individual electrode 4 at a contact portion 8 without an insulating film 6, thereby forming a matrix wiring portion 5.

One end of the output electrode 7 is connected to a pad portion 7a arranged at a predetermined position on the substrate 1, and is also commonly connected to a plating lead portion 7b shown with a dot in the figure.
One large pad portion 7c is connected to this lead portion 7b. These are patterned at the same time as the output electrode 7 and the plating lead part 7b.
A thickness of several hundred amps is sufficient. Note that the plating lead portion 7b and pad portion 7c, which are shown with dots, are arranged outside the effective portion of the sensor board 1.
This portion is cut together with the substrate 1 during the final substrate cutting.

Next, the output electrode 7 is electrolytically plated to form a plating film of Au or the like with a thickness of several thousand amps to several μm. This plating film significantly reduces the wiring resistance of the output electrode 7. The plating lead portion 7b and the pad portion 7c are provided to facilitate wiring work in the agate wood process, and will be cut later as described above.

Effects of the Invention As is clear from the above explanation, according to the present invention, even if the wiring pattern of the output electrode is thin and thin by forming a thin film to reduce the area of the sensor substrate, the wiring resistance can be reduced by applying electrolytic plating afterwards. can be made small enough,
Moreover, since it is a simple process of electrolytic plating, there is no loss of quality. Therefore, it is possible to reduce the size of the sensor and reduce the wiring resistance, and it is possible to mass-produce highly reliable image sensors with a high yield.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a wiring layout configuration in a manufacturing process according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a typical wiring layout configuration of an image sensor. 1... Substrate, 2... Light receiving element, 3... Common electrode,
4... Individual electrode, 5... Matrix wiring section, 6...
・Insulating film, 7... Output electrode, 8... Contact part, 7
b...Lead part for plating. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure a \

Claims (1)

[Claims] The output electrode wiring pattern in the matrix wiring part of the image sensor is formed into a thin film by a lift-off method or the like, and then electrolytic plating is performed using the wiring pattern as a negative electrode to form a plated film made of a predetermined conductive material on the wiring pattern. A method for manufacturing a matrix wiring part of an image sensor.