JPS6223087A - Display elememt - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a display element comprising an electro-optic medium sandwiched between substrates having electrodes, and particularly relates to a display element having an electro-optic medium sandwiched between substrates having electrodes. The present invention relates to a display element having a three-layer structure with an insulating film sandwiched therebetween.

[Prior Art] Recently, development of thin displays has been actively conducted due to demands for office automation equipment terminals, portable televisions, and the like. Among these, in information display devices in which electrodes are arranged in rows and columns in order to support large-capacity graphic displays, there are two types of information display devices: an active matrix method in which active elements are arranged at the intersections of the electrodes, and a high Two types of methods for driving the duty are being studied. These latter methods are already used in personal computers, word browsers, etc., but they have the problem that display quality deteriorates as the number of displayed characters increases, and the former method causes many active elements to become defective. Practical implementation has been delayed because it is difficult to manufacture without.

[Problem to be Solved by the Invention 1] In the case of a display element that does not use such an active element, as the number of display pixels increases, the number of terminals to be drawn out increases, or the number of conductive thin films used as lead wires increases. As wiring on the substrate becomes complicated, it is desired to increase the degree of freedom in wiring by wiring conductive SS in two layers with an insulating layer in between. In addition, in the case of display elements using active elements, it is possible to display high-density information with good visibility, but it is not possible to connect the conductive thin film underneath. It is necessary to sandwich and stack insulating films, and use a portion of the insulating films to conductively connect the upper and lower conductive thin films. Furthermore, in this case, 1
Since at least one active element is required for each pixel, it is extremely difficult to produce a large number of active elements without defects, and in order to repair these defects, conductive connections between the upper and lower conductive thin films are required. I need to take it.

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and uses a substrate in which electrodes are arranged on an insulating substrate, and an electro-optic medium is placed between the pair of substrates. A display element having a three-layer structure in which a part of the electrode of at least one of the substrates sandwiches an insulating film and conductive F11 films on the upper and lower sides; This is a display element characterized by having a structure in which at least a part of the portion is vertically electrically connected by laser irradiation.

The present invention has a three-layer structure consisting of an insulating film and a conductive thin film on the upper and lower sides, and conducts electricity in the vertical direction using a laser in at least a part of the three-layer structure. It is characterized by a conductive connection.

A brief explanation of the connection method using this method will be added here. A cross-sectional view of the three-layer structure is shown in FIG. 1(a), where (1) shows the glass substrate, (2) and (4) the conductive thin films, and (3) the insulating film. When a substrate with this structure is irradiated with a laser from above, it becomes shaped as shown in (b). At this time, the upper or lower conductive material covers the exposed surface of the insulating film,
Conductivity can be established between the upper and lower conductive thin films. This conductive connection is stable during cleaning processes, current tests, etc., and enables reliable conductive connection, and does not require a mask to form a hole, such as a contact hole, in a specific position in the insulating film. Not only is productivity good, but
Even if the position of the conductive connection changes, it is only necessary to change the position of the laser irradiation, so it is suitable for the production of many types of products and for repairing defective parts whose locations have not been determined.

In order to repair this defective area, it is preferable to form an auxiliary wiring that is not connected to the conductive thin film that has the defective area and use this as a bypass. Auxiliary wiring that is not connected to the thin film is formed, and when a defective point occurs, this defective point can be removed by cutting, etc., and then this auxiliary wiring can be used to perform its original function. . In addition, when manufacturing a structure in which a conductive thin film is sandwiched between insulating films, this auxiliary wiring can be formed at the same time as one of the conductive thin films, so there is no need to increase the number of manufacturing steps. Not only does it have a repair function without any defects, but the pattern shape is devised in advance to make it easier to connect, and auxiliary wiring is arranged to deal with various defects.
This method has the characteristics of making this method easier and more reliable.

For example, by arranging a large number of segment-side electrodes in a line on one board, and arranging a large number of line-shaped electrodes perpendicular to the common-side electrode on the other board, no active elements are used. A dot matrix display element can be constructed, but in such a layered display element, if this line-shaped electrode is cut during the manufacturing process, the display beyond the cut point will no longer be visible.In this case, as shown in Fig. 2. By arranging auxiliary wiring using a portion not related to display, this auxiliary wiring can be used as a bypass to repair this defect. The example in Figure 2 is
This shows the pattern of the conductive thin film that is the electrode on the segment side substrate.
In addition to 11), there is a second auxiliary wiring (12) on the left side, and a segment electrode (11) that is originally required on the upper side of the board in the figure.
A first auxiliary wiring (13) is formed through an insulating film, and a third auxiliary wiring (14) is formed below with an originally required segment electrode (11) through an insulating film. If the segment electrode (11) is cut, the intersection of the first auxiliary wiring (13) and the segment electrode (11) (15), the second auxiliary wiring (12) and the first auxiliary wiring wiring(
13), the intersection (!7) of the second auxiliary wiring (12) and the third auxiliary wiring (14), and the intersection of the third auxiliary wiring (14) and the segment electrode (11). The upper part of the segment electrode (11) is connected to the first auxiliary wiring (
13), second auxiliary wiring (12) and third auxiliary wiring (1
4) can be connected to the lower side of the segment electrode (11), and the entire segment electrode (11) can be pulled out to the outside and defects can be repaired.

Of course, in this case, the second auxiliary wiring (12) may be used as a terminal to be taken out to the outside as it is, or a plurality of auxiliary wirings may be arranged in parallel, and various applications are possible as to how to arrange the auxiliary wiring.

In the present invention, the defect can be easily repaired by forming an auxiliary wiring insulated from the originally required electrode as in the above example.

Of course, the present invention is not limited to repairing defects.

It is clear that it can also be used for electrically conductive connections between stacked electrodes in general.

Furthermore, the present invention is not limited to display elements that do not use active elements as described above, but can also be applied to a substrate for a wobbling element in which one or more active elements are formed in each pixel, and in the repair process, In addition to making a conductive connection by laser irradiation, a process of cutting off the short-circuited part of the conductive thin film where a short circuit has occurred or a process of cutting off the defective active element may be used in conjunction with the process, if necessary.

In this case, since the laser device used for conductive connection can be used for this cutting process, one device can have both the cutting and connecting functions. Furthermore, since evacuation, gas introduction, etc. are not required, the substrate processing capacity can be greatly improved.

Furthermore, defects can occur at any location on the active element substrate, and the probability that adjacent active elements become defective is extremely low. Therefore, one pixel is provided with multiple active elements, and in the initial state, the first If there is a defect in the first active element, the defective part is deleted, that is, the first active element is separated from the matrix electrode and the display pixel electrode. , and a second t@
By conductively connecting the active element to the matrix electrode and the display pixel electrode, the second active element can be used, eliminating line defects and point defects, and improving the yield of the active element substrate. Make things possible 1#.

Even in the case of these single-driving element substrates, matrix electrodes,
Repair is facilitated by forming an auxiliary electrode that is electrically insulated from the active element electrode and the display pixel electrode.

In particular, the present invention is particularly effective when two or more layers of conductive thin films are originally formed, such as in the case of an active element substrate.
There is no need to add a film forming process, and there is no need to reduce productivity.

In the present invention, the conductive thin film laminated via the insulating film is
Even if it is a transparent conductive thin film such as ITO (1n20+-9nO2) or 5nOz, A1. For example, in the example of FIG. 2, the segment electrode (11) is a transparent conductive thin film, which may be a metal conductive thin film such as Cr.
The first auxiliary wiring (12) and the second auxiliary wiring (14) may be a transparent conductive thin film or a metal conductive thin film.

Active elements of the present invention include thin film transistors, thin film diodes, MIM (metal-insulating film-metal), etc.
Adaptation to any active element is the rotation part.

The present invention consists of substrates on which electrodes are arranged so that the electrode surfaces face each other, and an electro-optic medium is sandwiched between them, and is applicable to liquid crystal display elements, electrochromic display elements, electrophoretic display elements, etc. It is.

[Function] According to the display element of the present invention, conductive connection can be easily made by irradiating a laser beam to a three-layer structure portion in which a conductive thin film is laminated with an insulating film interposed therebetween, and the position of the laser irradiation can be adjusted. Since it is easy to change the position of the conductive connection by simply changing the position, it can be easily applied to the case where the position of the conductive connection is changed for each board and to the case of manufacturing a wide variety of products.

Furthermore, according to the display element of the present invention, some of the conductive P! It is possible to cut the film and conduct the conductive connection using the same laser device, resulting in good productivity.

Furthermore, by ablating a portion of the conductive thin film and making conductive connections using laser irradiation, defects caused by defects in the conductive thin film or active elements, mutual short circuits, etc. can be easily repaired, and a defect-free display can be performed. According to this method, the manufacturing yield can be easily increased by 1
00%, when using a display element using active elements as an information display device, it is possible to sufficiently compensate for the disadvantage of high manufacturing cost compared to conventionally used dot matrix and the like.

``Example'' Example 1 The structure of the six display elements shown below is an example of a dot matrix display element using auxiliary wiring according to the present invention.
It is the same as shown in the figure. ITO (In203-!) was deposited as a conductive thin film on a glass substrate as an insulating substrate.
Jr! p2) Form a g film.

After forming the segment electrode and the first auxiliary wiring by cholera patterning, the segment electrode and a part of it are connected to the end of the segment electrode on the terminal side and the end opposite to the end of the segment electrode via the insulating film of 5i02. A thin film of AI was formed so as to be laminated to form a segment substrate, and a common substrate on which a common electrode was formed was created.

If it is found through inspection that a disconnection has occurred in this segment electrode, the portion where the disconnected segment electrode is laminated with the first auxiliary wiring at the end opposite to the terminal side, the first auxiliary wiring Laser irradiation is performed on four locations of the laminated portion of the second auxiliary wiring, the laminated portion of the second auxiliary wiring and the third auxiliary wiring, and the laminated portion of the third auxiliary wiring and the terminal side portion of the segment electrode to establish conductive connection. The broken segment electrode was repaired by taking the following steps.

Next, the segment substrate and the common substrate were arranged so that the electrode surfaces faced each other, the periphery was sealed with a sealing material, and the inside was filled with liquid crystal to form a liquid crystal display element.

Embodiment 2 FIG. 3 shows an example of a cross-shaped display that cannot be displayed without laminated wiring, and the display pattern is a bar graph surrounded by a frame. Figure 3 (
a) shows the pattern of the conductive thin film of the underlying layer; (b)
shows the pattern of the conductive thin film in the upper layer.

A thin film of In203-SmO2 is formed on a glass substrate and patterned to form segment electrodes (21) of the frame and each segment electrode (22) of the bar graph.
Conductive thin film (23) for leads to connect to (2)
0 and first auxiliary wiring for leads (25), (28)
.

(27) is formed, and then an ITO thin film is formed again through the Si02 insulating film, and a segment electrode (21) for displaying a frame pattern, a segment electrode (22) for displaying a bar graph pattern, and a second auxiliary The conductive thin film on the upper layer and the conductive thin film on the lower layer are then electrically connected by laser irradiation at the part (28) in FIG. A segment substrate was formed which was connected to the terminal through the conductive thin film. In this case as well, if a defective part such as a short circuit or cut occurs in the conductive thin film that is the original lead pattern, the short circuit part should be cut out and formed as an auxiliary wiring in the case of a short circuit. Repair could be easily made by making a conductive connection using laser irradiation at the portion (30) of the preliminary lead pattern in FIG.

A liquid crystal display element was fabricated by facing this segment substrate and a common substrate on which common electrodes were formed at corresponding positions. In the case of this liquid crystal display element, since the two-layer conductive thin film is originally formed, there is an advantage that the auxiliary wiring can be formed without any new process. Although only a simple wiring example was used in this example, if necessary, in order to connect one electrode to another, two or more conductive connection points, two or more auxiliary wirings, such as the above It is clear that the auxiliary wiring of the conductive thin film and the auxiliary wiring of the underlying conductive thin film may each be connected one or more times.

Example 3 A substrate having two thin film transistors (TPT) in one pixel was formed. In this substrate, the first TPT and the second TPT
PT was made to have the same structure. Therefore, the first T
It is necessary to connect the drain electrode of the PT and the gate electrode of the second TPT. Since conductive connection was made using wiring and via an insulating film, this conductive connection was made by laser irradiation. At the same time, conductive connection between the display pixel electrode and the second TPT, conductive connection between the power line and the source electrode of the second TPT, etc. can also be performed.

A liquid crystal display element was prepared by placing this TPT substrate and a substrate on which a transparent conductive thin film was formed in the corresponding portions to face each other.

[Effects of the Invention] In the display element of the present invention, conductive connection can be easily made by irradiating a laser beam onto a three-layer structure portion in which a conductive thin film is laminated with an insulating film interposed therebetween. It is easy to change the position of the conductive connection by simply changing the position, and it can be easily applied to the case where the position of the conductive connection is made different for each board and to the case of manufacturing a wide variety of products.

Furthermore, in the display element of the present invention, the cutting of the conductive thin film and the conductive connection can be performed using the same laser device, and the productivity is high.

Furthermore, by ablating a part of the conductive thin film and making conductive connections using laser irradiation, defects caused by defects in the conductive thin film or active elements, mutual short circuits, etc. can be easily repaired, and manufacturing yields can be increased. This can reduce costs and, in turn, greatly contribute to the practical application of active Madrisk panels.

Further, in the above description, the explanation has been mainly given to liquid crystal display elements, but it is naturally applicable to electrochromic display elements, electrophoretic display elements, etc., and various applications will be made in the future.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are cross-sectional views showing a state (a) before electrical conduction is established in the earthwork head and a state (b) after electrical conduction is established according to the present invention. FIG. 2 is a plan view showing an example of a pattern of a conductive thin film of a segment electrode substrate for a display element of the present invention. FIG. 3 is a plan view showing the pattern of Example 2, and (a
) shows the pattern of the conductive thin film in the lower layer, and (b) shows the pattern of the conductive thin film in the upper layer. Glass substrate: 1 Conductive thin M: 2,4 Insulating film: 3 Segment electrode: 11 Second auxiliary wiring: 12 First auxiliary wiring: 13 Third auxiliary wiring: 14 Intersection: 15. IEi, 17.18th
/VJ 3rd) 1 (α)

Claims (4)

[Claims] (1) In a display element using a substrate in which electrodes are arranged on an insulating substrate, and an electro-optic medium is sandwiched between the pair of substrates, a part of the electrode of at least one of the substrates has an insulating film. The scissors have a three-layer structure consisting of conductive thin films on the upper and lower sides, and at least a part of the three-layer structure has a structure in which conduction is established in the vertical direction by laser irradiation. display element. (2) The display element according to claim 1, wherein at least one conductive thin film of the three-layer structure is an auxiliary wiring insulated from other conductive thin films. (3) The display element according to claim 1 or 2, wherein at least one of the conductive thin films is a transparent conductive thin film. (4) Claim 1 or 2, wherein the substrate having the three-layer structure is a substrate having electrodes arranged in rows and columns, and a thin film active element provided near the intersection of the electrodes in the rows and columns. display element.