JP5089266B2 - Manufacturing method of image display element - Google Patents

Description

The present invention relates to a large-sized image display device configured by arranging a large number of liquid crystal display (LCD) panels, plasma display panels (PDP), electroluminescent (EL) display panels, and the like. it relates manufacturing method of an image display element.

  A large display is a system in which a plurality of flat displays (for example, LCD panels, PDPs, EL display panels, etc.) are arranged in a matrix form as image display elements (or display units) in order to achieve high performance at a low price. Is adopted. 10A and 10B are schematic configuration diagrams of an image display apparatus which is a conventional large display, in which FIG. 10A shows the overall configuration, and FIG. FIG. 11 is an enlarged cross-sectional view of the joint portion of the image display element constituting the image display device of FIG. 10 as viewed from XI-XI.

As shown in FIG. 10A, a large-screen image display device is configured by arranging a plurality of unit image display elements 20 in a matrix. As shown in FIG. 11, the image display element 20 includes a front panel 21 and a back panel 22 made of a glass plate or the like. The front panel 21 and the back panel 22 are opposed to each other with a predetermined interval, and a plurality of pixels 23 and a plurality of electrodes 24 for controlling them are arranged therebetween to form a light emitting layer (or liquid crystal layer). And the periphery is sealed with a sealing portion 25. FIG. 10B shows a state where the pixel 23 is seen from the viewing side through the transparent front panel 21.
A lead line 26 for applying a voltage to the electrode 24 is drawn around the image display element 20, that is, from the joint portion 27 of the adjacent image display element 20.

When the gap Ga (see FIG. 10) between the pixels 23 of the adjacent image display elements 20 in the joint portion 27 is larger than the pixel gap Gb in the same image display element, the joint portion 27 becomes conspicuous.
Therefore, rather than pulling out the leader line from the peripheral edge of the image display element, the back panel 22 is divided into two to provide a gap at the center, and electrode pins or lead-outs as shown in the figure are applied to the electrode terminals exposed in the gap. A technique for connecting the wire 26 and pulling it out of the back panel 22 is disclosed (for example, see Patent Document 1).

  In addition, as another example in which the joint portion of the image display element is made as small as possible, as shown in FIG. The plurality of first end surface wirings 30, the plurality of second end surface wirings 32 provided on the end surface of the back plate 31, and the plurality of lines provided on the back surface of the back plate 31 and connected to the second end surface wiring 32. And a plurality of side surface connection wirings 35 provided on the sealing material 34 on the side surface and connecting the first end surface wiring 30 and the second end surface wiring 32 to each other. Is disclosed (for example, see Patent Document 2).

JP 2001-251571 A (3rd page, FIGS. 2 and 4) JP 2000-122571 A (2nd page, FIG. 5)

The large screen display device is provided with a sealing portion for sealing the light emitting layer between the front panel and the back panel, and a lead line for applying a voltage to the electrodes at the end of each image display element. Therefore, the pixel gap Ga in the joint portion 27 of the adjacent image display elements is larger than the pixel gap Gb in the same image display element due to the sealing width g1 of the sealing portion 25 and the electrode lead-out allowance g2. Then, there existed a problem that a seam part became conspicuous. In order to make the pixel arrangement pitch P1 uniform, when the pixel interval Gb in the same image display element is made to coincide with the large pixel interval Ga in the joint portion, a request for high luminance brightening and high resolution of a large display is required. There was a problem that could not be achieved.

As a countermeasure, in the image display element such as Patent Document 1 in which the back panel is divided and a leader line is drawn from the gap of the divided part so that the joint part between the image display elements is not enlarged, the divided part has As a result, there is a problem that the structure becomes complicated.
Further, in the image display device as in Patent Document 2, the non-display area of the joint portion can be reduced. However, when the image display elements are brought into contact with each other, the side wiring portions are brought into contact with each other. There is a problem that it is necessary to sufficiently insulate, and there are a portion where the side connection wiring is formed and a portion where the side connection wiring is not formed on the side surface.

The present invention has been made in order to solve the above-described problems. When a plurality of image display elements are arranged in a matrix, the image display elements can be narrowed by aligning seams. an object of the present invention is to provide a manufacturing how the child.

A method for manufacturing an image display element according to this invention comprises a front panel, a back panel facing the front panel with a small size than the front panel, the state of the display or non-display are arranged in a matrix between both of the panels In a method for manufacturing an image display element having a plurality of selected pixels and a plurality of electrodes connected to the pixels, and the panels are bonded to each other , the pixels on the surface of the front panel facing the back panel Forming electrodes and electrodes, providing electrode connection portions led out from the respective electrodes on the peripheral edge, attaching the back panel together, and forming the electrode connection portions on the side facing upward, the electrodes Both panels so that the ridgeline formed by the connecting surface and the side surface of the front panel that follows it, and the ridgeline formed by the upper side surface of the back panel and the back surface that follows the ridgeline are located on substantially the same horizontal plane. Applying a paste-like conductive material using a dispenser device in a tilted state, forming a side wiring from the electrode connection portion to the side surface of the back panel, and forming a side wiring on the back side of the back panel And a step of forming a subsequent back surface wiring with a paste-like conductive material.

According to the manufacturing method of the image display device of this invention, after bonding the two panels provided with electrode connection portion to the peripheral portion of the front panel, as a step forming a wiring portion, the side surface portions of the back panel from the electrode connecting portions In addition, there are a step of forming a side wiring by applying a paste-like conductive material using a dispenser device, and a step of forming a backside wiring following the side wiring with a paste-like conductive material on the back side of the back panel. Side wiring can be easily formed with simple equipment, and extraction of electrodes is simplified, so that manufacturing equipment and manufacturing processes can be simplified, manufacturing costs can be reduced, and high-quality image display elements are provided at low cost. be able to.

Embodiment 1 FIG.
FIG. 1 is a front view showing a schematic configuration in a case where image display elements using the EL display panel according to Embodiment 1 as an example are arranged in two rows and two columns on the same plane, and FIG. 2 is a rear view thereof. 3 is a perspective view of a single image display element as viewed from the back side, and FIG. 4 is an enlarged cross-sectional view showing a joint portion between the image display elements.
In addition to the EL display panel, the image display element may be a flat display unit such as an LCD panel or a PDP. Although the case of four sheets is shown in the figure, in the case of a large-screen image display device, a larger number are arranged in a matrix.

  As shown in FIGS. 1 to 4, the image display element 10 includes a transparent front panel 1 and a back panel 2 made of a glass plate or the like. The front panel 1 and the back panel 2 are opposed to each other with a predetermined interval, and a plurality of pixels 3 for selecting a display state or a non-display state are arranged in a matrix between the panels 1 and 2. . The pixel 3 is composed of display cells 3a, 3b, and 3c of three colors of red (R), green (G), and blue (B), and each pixel 3 is arranged at a constant display pixel interval. The front view of FIG. 1 is a view seen from the viewing side, and shows a state where the pixel 3 is seen through the front panel 1.

  The pixel 3 includes a light emitting layer 4 and an electrode 5 provided orthogonally across the light emitting layer 4. The electrode 5 is made of a transparent electrode or a metal electrode. The front panel 1 is formed slightly larger than the rear panel 2, and the electrode connecting portion drawn out from the electrode 5 here is defined as an electrode lead-out allowance g <b> 2, which is the difference surface between the two panels formed on the peripheral edge when arranged opposite to each other. 6 is provided. Since the end portions of both panels are sealed by the sealing portion 7, the electrode 5 passes through the sealing portion 7 and communicates with the external electrode connection portion 6.

As shown in FIGS. 2 and 3, a connector 8 is mounted on the back surface 2a of the back panel 2 (the surface opposite to the surface facing the front panel 1 will be referred to as a “back surface”). ing. And the electrode connection part 6 and the connector 8 are electrically connected by the wiring 9 formed of the paste-like conductive material. The wiring 9 formed from the electrode connecting portion 6 to the back surface 2a via the side surface 2b of the back panel 2 is applied using, for example, a dispenser device. Details of the coating method will be described later. In addition to application using a dispenser device, for example, an ink jet type device is also possible.
The image display element 10 configured as described above is supplied with electric power from the external drive circuit (not shown) to the pixel 3 through the connector 9 via the connector 8.

  The paste-like conductive material is silver, gold, carbon paste or the like, and has a viscosity of a certain level (for example, 150 dPa · s or more), the electrode 7 is connected to the sealing portion 7 even when a narrow pitch electrode wiring is formed. The paste-like conductive material does not flow between the portions 6 and a short circuit between the adjacent electrode connection portions 6 or wirings 9 can be prevented.

It is effective if a low-temperature curable silver paste is used as the paste-like conductive material. The silver paste generally needs to be fired at a high temperature. However, the low-temperature curable silver paste can be cured at a lower temperature than the high-temperature baked silver paste, thereby simplifying the production equipment.
In addition, by using a low-temperature curable silver paste, the image display element 10 may be applied to an organic EL that is considered to be weak at high temperatures, or may be applied to a film-like display device such as deformable electronic paper. It becomes possible and the use is expanded.
Furthermore, as will be described later, when an electronic component other than the connector 8 is mounted on the back surface 2a of the back panel 2, and wiring is performed with a paste-like conductive material after mounting, wiring can be performed without damaging the electronic component.

As described above, in the image display element 10 according to the present embodiment, it is possible to easily perform the wiring of the electrode lead without increasing the electrode lead allowance g2.
In the conventional configuration as described with reference to FIG. 11, it is necessary to connect, for example, a flexible cable or the like by an ACF (Anisotropic Conductive Film) at the end face of the image display element. It was necessary to secure a width of about 3 mm. On the other hand, according to the present embodiment, since the electrode lead-out allowance g2 can be realized at around 0.2 mm, the dimension of the joint portion can be greatly shortened when a plurality of image display elements 10 are arranged. Further, since the seam portion is joined at the side surface of the front panel, the end faces are aligned and the seam is neatly aligned.
Although details will be described later, if the width dimension of the electrode lead-out allowance g2 is set to be equal to or less than the thickness of the back panel, it is easier to form the wiring on the side surface.

2 to 4 show the case where the wiring 9 drawn out from the electrode connecting portion 6 is directly connected to the connector 8 provided on the back panel 2, but FIG. 5 shows another example of wiring.
Since the paste-like conductive material can be easily applied to an arbitrary shape by adjusting to an appropriate viscosity, the electronic component 11 is mounted on the back surface 2a of the back panel 2 taking advantage of such characteristics. The wiring is made to the connector 8 via the electronic component 11.
First, the wiring 9 formed on the back surface 2 a is connected to the electronic component 11 from the electrode connecting portion 6 via the side surface 2 b of the back panel 2. Furthermore, wiring 12 made of a paste-like conductive material is formed from the terminal portion of the electronic component 11 to the individual terminals of the connector 8 to ensure conduction. The electronic component 11 may be attached to the back surface 2a using an adhesive or the like.

The electronic component 11 includes, for example, a driver IC for the image display element 10. By attaching these ICs to the back panel 2 and wiring them first, the number of connectors and the number of pins can be reduced compared to the case of connecting directly with the connectors 8 as shown in FIGS. Therefore, it becomes easy to insert / remove to / from the unit in which the image display element 10 is incorporated.
Usually, the larger the fitting area of the connector 8, the greater the friction. Therefore, the force required for insertion / extraction increases, and if this becomes too large, the image display element 10 may be destroyed during operation. When the number of electrodes inside the image display element 10 is large, by mounting the driver IC, the electrical wiring from the connector 8 to the electronic component 11 is only the input signal of the driver IC. The number and size can be reduced. In addition, since it is not necessary to secure a space for mounting electronic components on the unit substrate side on which the plurality of image display elements 10 are assembled, a simple circuit configuration can be achieved and cost reduction can be achieved.

  As described above, according to the image display device of the present embodiment, the electrode connection portion led out from each electrode is provided at the peripheral edge portion of the front panel facing the back panel, and the side surface of the back panel from the electrode connection portion. Since the plurality of wirings connected to the respective electrodes are formed of the paste-like conductive material over the back surface through the above, the wiring drawn out from the electrodes is simplified, and the size of the electrode extraction portion of the image display element can be reduced.

In addition, since the paste-like conductive material is a low-temperature curable silver paste, there is no need for high-temperature firing, which simplifies the manufacturing equipment. In addition, when electronic components are mounted and wired, wiring can be performed without damaging the electronic components. Furthermore, since an organic EL or the like that is vulnerable to high temperatures can be applied as a display device, the application of the image display element is expanded.

In addition, since the wiring is directly connected to the connector mounted on the back side of the back panel or connected to the connector via the electronic component mounted on the back side, the unit substrate side on which a plurality of image display elements are assembled In addition, since it is not necessary to secure a space for the connector or the electronic component, a simple circuit configuration can be achieved, and the cost can be reduced.
In particular, a connector connected to a connector via an electronic component can be reduced in size by reducing the number of connectors and the number of pins. Therefore, it can be easily inserted into and removed from a unit in which an image display element is incorporated.

Embodiment 2. FIG.
FIG. 6 is a perspective view of the image display element according to the second embodiment, and is a view seen from the back side. The same parts as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and differences will be mainly described.
The difference is the means for forming the wiring to the back surface 2a of the back panel 2.
That is, among the wirings 9, a plurality of wirings formed on the flat surface portion on the back surface 2a side of the back panel 2 are formed by printing using a screen printer in a lump without using a dispenser device. Is. In the figure, since an example in which electronic components are mounted is shown, the wiring on the back surface 2a side is wiring 9 and wiring 12.

However, even in this case, the wiring from the electrode connection portion 6 through the side surface 2b of the back panel 2 to the back surface 2a is formed by a dispenser device (or an ink jet device), and the flat portion of the back surface 2a of the back panel 2 Only using a screen printer.
In this case, the attachment and electrical connection of the connector 8 and the electronic component 11 described in the first embodiment are subsequent processes.

  In the present embodiment, a plurality of image display elements 10 are held side by side as shown in FIG. 6 in addition to wiring the back surface 2a of the back surface 2a of one image display element 10 all together as described above. In this state, the wirings of the back surfaces 2a of the plurality of image display elements 10 can be collectively formed using a screen printer. In this way, wiring can be formed in a short time and workability is improved.

  As described above, according to the present embodiment, among the wirings, the plurality of wirings formed on the flat surface portion on the back surface side of the back panel are formed by printing all together, so that complicated wiring patterns can be easily formed. Can be formed. Furthermore, since it is possible to print not only one image display element but also a large number of elements at the same time, the manufacturing time can be greatly reduced.

Embodiment 3 FIG.
FIG. 7 is a cross-sectional view of a main part of the image display device according to the third embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, description thereof will be omitted, and differences will be mainly described.
The difference is that the surface of the wiring and the surface of the connection terminal portion of the connector to which the wiring is connected (also on the surface of the connection terminal portion when an electronic component is mounted) are covered by forming a protective film 13 with an insulating protective material. This is the point. This protects wiring parts such as panel edges that are easily damaged by mechanical shock, ensures long-term reliability of the wiring itself, and prevents the image display element 10 from being affected by humidity and the like. To protect.

In particular, when using a low-temperature curable silver paste, there are cases where the strength of the paste-like electrode and the reliability for long-term use may be uneasy depending on the usage environment, as compared with a method of firing at a high temperature. By forming the protective film 13 made of an insulating protective material on the surface of the wiring 9 made of a paste-like conductive material, moisture can be cut off and the strength and reliability can be ensured. The protective film 13 may be made of any material that blocks moisture. As a method for forming the protective film 13, coating or the like is effective.

  The sealing part 7 of the image display element 10 is generally transparent. Therefore, in the protective film formed from the side surface portion to the back surface, at least a portion covering the side surface of the back panel 2 and the wiring in the vicinity thereof is made of a black material, so that light leaking from the sealing portion 7 can be reduced. . That is, the black portion 13 a shown in FIG. 7 is a region corresponding to the sealing portion 7.

As described above, according to the present embodiment, since the wiring and its connection terminal portion are covered with the protective film, the wiring portion and its connection portion are protected, and long-term reliability of the wiring portion is ensured. The
Further, since at least a portion of the protective film covering the side surface of the back panel and the wiring in the vicinity thereof is made of a black material, light leaking from the sealing portion can be reduced, and a reduction in contrast can be suppressed.

Embodiment 4 FIG.
The image display element has been described so far. Embodiment 4 is a case where these image display elements are used to constitute a large-screen image display device.
A plurality of image display elements 10 are arranged in a plurality of rows, a plurality of rows, and a matrix with the front side of the front panel 1 as the viewer side, and end faces are made into one large screen image display device. The image diagram is equivalent to FIG. 10A described in the background art section.
If the image display element 10 described in the first to third embodiments is applied, the size of the non-display portion of the joint portion of the adjacent image display elements can be greatly reduced. A large and large image display device can be effectively constructed.

For example, in recent large screen display devices, the method of arranging LEDs is the mainstream, and as the resolution increases, the arrangement of LEDs increases in density and the cost increases.
Therefore, when a light emitting device such as PDP or organic EL is applied to the display pixels of the image display elements described in the first to third embodiments and arranged in a matrix, an inexpensive and high-definition image display device is realized. can do.
Furthermore, when a reflective display device that reflects external light such as liquid crystal or electronic paper is applied and arranged in a matrix, an inexpensive information display device with ultra-low power consumption can be realized.

  As described above, according to the present embodiment, any one of the image display elements described in the first to third embodiments is used, and a plurality of the image display elements are arranged in a matrix form to obtain a large screen. Therefore, the joint width between the image display elements is reduced, the seam portion that is a non-display portion is not conspicuous, the image quality is improved, and a large-screen image display device with high visibility can be obtained. it can.

Embodiment 5 FIG.
Embodiment 5 relates to a manufacturing method. Since the configuration of the image display element is the same as that described in the first to third embodiments, the same parts are denoted by the same reference numerals and the description thereof is omitted. 8 and 9 are diagrams for explaining a method of manufacturing the image display element 10, and particularly a part related to a method of forming a wiring. The principal part enlarged view is shown in the dashed-dotted line of each figure.

  Prior to the process shown in FIG. 8, the process until the front panel 1 and the back panel 2 are bonded together is completed. That is, the light emitting layer 4 and the electrode 5 of the pixel 3 as described in the first embodiment are formed on the surface of the front panel 1 facing the back panel 2, and the electrode connection portion 6 drawn from the electrode 5 is provided at the peripheral portion. Provided, the back panel 2 is overlapped on the front panel 1, the outer peripheral part is sealed with the sealing part 7, and bonded together to form a single body.

Next, as shown in FIG. 8, the side surfaces of the panels 1 and 2 on the side where the electrode connection portion 6 is provided face upward, and the formation surface of the electrode connection portion 6 and the subsequent side surface 1 b of the front panel 1 In a state in which both panels 1 and 2 are inclined so that the ridge line Pa to be formed and the ridge line Pb formed by the upper side surface 2b of the back panel 2 and the back surface 2a following the ridge line Pb are located on substantially the same horizontal plane Lh. Hold.
Next, the dispenser device 14 injects a paste-like conductive material from the nozzle 14a at the tip thereof, and individually covers the sealing portion 7 and the side surface 2b of the back panel 2 from the terminals of the electrode connection portion 6 to the back surface 2a. The side wiring 9a is formed by coating.

  By inclining at an angle as described above, interference between the nozzle 14a of the dispenser device 14 and the ridge lines Pa and Pb portions of both the panels 1 and 2 of the wiring forming portion can be reduced, and coating can be facilitated. In addition, on the ridge line Pb side of the back panel 2, the application position is slightly applied to the back surface 2 a side of the back panel 2, thereby facilitating connection with the back surface wiring 9 b on the back surface 2 a in the next process. .

Here, if the width dimension of the portion of the front panel 1 where the electrode connection portion 6 is provided, that is, the electrode lead-out allowance g2 is equal to or less than the thickness t of the back panel 2, the bonded panels 1 and 2 are attached. The angle α when arranged obliquely can be set to an angle of 45 ° or less with respect to the vertical direction, and can be set close to the vertical. In addition, although the thickness of the sealing part 7 is exaggerated and thickly expressed for easy understanding in the drawing, the thickness is actually much smaller than the thickness t of the back panel 2.
As a result, even when the side surface 7a of the sealing portion 7 is recessed, it faces upward, so that when the paste-like conductive material is applied, it becomes easy to enter the recessed portion and the connection with the electrode connecting portion 6 is reliably performed. be able to. If the angle α is large, the paste-like electrode material will not easily enter the depression on the sealing side surface and may be cut off.

Next, as shown in FIG. 9, the back panel 2 is held horizontally with the back surface 2 a side facing upward, from the ridge line Pb of the back panel 2 to the terminal of the connector 8 (or electronic component 11) that has been bonded and fixed in advance. The back surface wiring 9b on the back surface side is formed by injecting and applying the paste-like conductive material by the dispenser device. In this way, wirings 9a and 9b from the electrode connecting portion 6 to the connector 8 are formed, and electrical connection is completed.
The back surface wiring 9b formed on the back surface 2a may be a printing method as described in the second embodiment.
Further, as described in Embodiment 3, the surfaces of the wirings 9a and 9b and the surface of the terminal portion of the connector 8 are covered with a protective film as necessary, or a part of the protective film is made black. The following measures may be taken.
Furthermore, it is effective to use a low-temperature curable silver paste as the paste-like conductive material.

As described above, according to the present embodiment, as the wiring portion forming step, the step of applying the paste-like conductive material from the electrode connecting portion to the side surface portion of the back panel to form the side surface wiring, Since there is a process for forming the backside wiring that follows the side wiring on the backside with a paste-like conductive material, wiring for electrode extraction can be easily performed, manufacturing equipment and manufacturing processes can be simplified, and manufacturing can be performed. Cost can be reduced.
Further, as a side wiring forming step, the side surface on the side where the electrode connection portion is formed is directed upward, the ridge line formed by the formation surface of the electrode connection portion and the side surface of the subsequent front panel, and the upper side of the back panel Since it was applied using a dispenser device with both panels tilted and held so that the ridgeline formed by the side surface and the subsequent back surface was located on the same horizontal plane, the side surface with simple equipment Since the wiring can be easily formed, the equipment can be simplified and the manufacturing process can be simplified, and the manufacturing cost can be reduced.

It is a front view which shows schematic structure at the time of arranging the image display element by Embodiment 1 of this invention in 2 rows 2 columns. FIG. 2 is a schematic rear view of FIG. 1. It is the perspective view which looked at the image display element of Drawing 1 and Drawing 2 from the back side. It is an expanded sectional view which shows the junction part of the image display elements of FIG.1 and FIG.2. It is the perspective view which showed the other example of the image display element by Embodiment 1, and was seen from the back surface side. 6 is a perspective view of an image display element according to Embodiment 2. FIG. FIG. 6 is a cross-sectional view of a main part of an image display element according to a third embodiment. It is explanatory drawing explaining 1 process of the manufacturing method of the image display element by Embodiment 5. FIG. It is explanatory drawing explaining the other process of the manufacturing method of the image display element by Embodiment 5. FIG. It is a schematic block diagram of the conventional image display apparatus. It is an expanded sectional view of the junction part of the image display element which comprises the image display apparatus of FIG. It is principal part sectional drawing which shows the other example of the conventional image display apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front panel 1b Side surface 2 Back surface panel 2a Back surface 2b Side surface 3 Pixel 3a-3c Display cell 4 Light emitting layer 5 Electrode 6 Electrode connection part 7 Sealing part 8 Connector 9 Wiring 9a Side surface wiring 9b Back surface wiring 10 Image display element 11 Electronic component 12 Wiring 13 Protective film 13a Black portion 14 Dispenser device 14a Nozzle g2 Electrode drawing allowance Lh Horizontal plane.

Claims (1)

A front panel, a back panel that is smaller than the front panel and faces the front panel, a plurality of pixels that are arranged in a matrix between the panels and selected to be displayed or not, and the pixels A plurality of electrodes connected to each other, and in the method for manufacturing an image display element configured by bonding the both panels,
Forming the pixel and the electrode on a surface of the front panel facing the back panel, providing an electrode connection portion led out from each electrode at a peripheral portion, and bonding the back panel together to form the integrated body; ,
A side surface on the side where the electrode connection portion is formed is directed upward, a ridge line formed by a formation surface of the electrode connection portion and a side surface of the front panel that follows, a side surface above the back panel, and a back surface following the back surface And applying a paste-like conductive material using a dispenser device in a state in which both the panels are inclined and held so that the ridge line formed by and the ridge line is located on substantially the same horizontal plane, Forming side wiring on the side surface of the panel;
And a step of forming, on the back surface side of the back panel, a back surface wiring following the side surface wiring with a paste-like conductive material.

Images