JP2008003114A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of having a substrate and a flexible wiring board suitably joined together. <P>SOLUTION: Disclosed is an organic EL display device A having a transparent substrate 1A, an anode electrode 21A and a cathode electrode 21B having terminal portions 21A and 21B comprising pluralities of beltlike portions 22A and 22B disposed on the transparent substrate 1A in parallel, and a flexible wiring board joined to the terminal portions 21A and 21B through anisotropic conductive resin, the plurality of beltlike portions 22A disposed closer to the center in the parallel direction (x) between the pluralities of beltlike portions 22A and 22B having a width w1 less than a width w2 of the plurality of beltlike portions 22B disposed closer to ends in the parallel direction (x). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device such as an organic EL display device.

  In addition to organic EL display devices, display devices that display a desired image by a plurality of pixels arranged in a matrix are widely used. FIG. 5 shows an example of a conventional organic EL display device. The organic EL display device X shown in the figure includes a pair of substrates 91A and 91B, an anode electrode 92A, and a cathode electrode 92B. The anode electrode 92A and the cathode electrode 93A have pixel forming portions 94A and 94B. The pixel forming portions 94A and 94B are each composed of a plurality of strip-shaped portions arranged in parallel. An organic layer is sandwiched between the intersections of the pixel forming portions 94A and 94B. These intersecting portions constitute a plurality of pixels arranged in a matrix in the display area 95. Further, the anode electrode 92A and the cathode electrode 92B have terminal portions 93A and 93B, respectively. The terminal portions 93A and 93B are each composed of a plurality of strip-shaped portions arranged in parallel in the direction x. These strip portions have the same width and are arranged at a constant arrangement pitch. The terminal portions 93A and 93B are joined to a flexible wiring board (not shown) via an anisotropic conductive film (not shown).

  However, in the step of bonding the flexible wiring board using the anisotropic conductive film, the anisotropic conductive film is heated and pressurized through the flexible wiring board. For this reason, the flexible wiring board extends, and the arrangement pitch of wiring patterns (not shown) formed on the flexible wiring board becomes uneven. In such a case, the wiring pattern is shifted with respect to the plurality of strips constituting the terminal portions 93A and 93B, and the anode electrode 92A and the cathode electrode 92B and the flexible wiring board can be appropriately conducted. It was inhibited. Further, in a state where the flexible wiring board is extended, it is difficult to align the flexible wiring board and the substrate 91A.

JP 2000-114677 A

  The present invention has been conceived under the circumstances described above, and an object thereof is to provide a display device capable of appropriately joining a substrate and a flexible wiring substrate.

  A display device provided by the present invention includes a transparent substrate, an electrode having a terminal portion composed of a plurality of strip-shaped portions arranged in parallel to the transparent substrate, and an anisotropic conductive resin bonded to the terminal portion. A flexible wiring board that is positioned near the center in the parallel direction among the plurality of strip-shaped portions, but whose width is positioned near the end in the parallel direction among the plurality of strip-shaped portions. It is characterized by being smaller than the width.

  According to such a configuration, even when the flexible wiring board is extended by the heating and pressurizing process when the flexible wiring board is bonded to the transparent substrate, the plurality of strip-shaped portions are close to the end in the parallel direction. Since those in the above are relatively wide, they can be overlapped with the wiring pattern formed on the flexible wiring board. Therefore, the flexible wiring board and the electrode can be appropriately conducted.

  In a preferred embodiment of the present invention, the arrangement pitch of the plurality of strips adjacent to each other near the center in the parallel direction is the same as the arrangement pitch of the plurality of strips adjacent to each other near the end in the parallel direction. The pitch is smaller than the arrangement pitch. According to such a configuration, even if the flexible wiring board extends toward the end in the parallel direction by heating and pressing, the wiring pattern of the flexible wiring board and the end in the arrangement direction among the plurality of strips It is possible to satisfactorily superimpose the objects located closer to each other. Therefore, it is suitable for conducting the flexible wiring board and the electrode.

  In a preferred embodiment of the present invention, the plurality of strips are arranged outward in the arrangement direction of the plurality of strips, and are made of the same material as the plurality of strips, One or more additional belt-shaped portions that do not belong electrically are provided, and the additional belt-shaped portion has a width equal to or smaller than that of the narrowest one of the plurality of belt-shaped portions. According to such a configuration, the flexible wiring board and the transparent substrate can be accurately aligned.

  Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the accompanying drawings.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  1 to 4 show an example of a display device according to the present invention. The organic EL display device A of the present embodiment includes a transparent substrate 1A, a sealing substrate 1B, an anode electrode 2A, a cathode electrode 2B, a dummy electrode 3, an anisotropic conductive film 4, and a flexible wiring substrate 5. In FIGS. 1 and 2, the anisotropic conductive film 4 and the flexible wiring board 5 are omitted for convenience of explanation.

  The transparent substrate 1A is made of, for example, glass and supports the anode electrode 2A, the cathode electrode 2B, the dummy electrode 3, and the organic layer (not shown). In the present embodiment, the transparent substrate 1A has a rectangular shape. The lower surface of the transparent substrate 1A in the drawing is a display area 10 of the organic EL display device A. That is, the organic EL display device A is configured as a so-called bottom emission type that emits light through the transparent substrate 1A.

  The sealing substrate 1B is made of glass, for example, and protects the anode electrode 2A, the cathode electrode 2B, the dummy electrode 3, and the organic layer. The sealing substrate 1B has a rectangular shape, and the dimension in the direction perpendicular to the direction x is smaller than that of the transparent substrate 1A.

  The anode electrode 2A is for supplying holes to the organic layer, and has a pixel forming portion 23A and a terminal portion 21A. The pixel forming portion 23A is composed of a plurality of strip-like portions each extending in a direction perpendicular to the direction x, and is made of a transparent portion by being made of, for example, ITO. The terminal portion 21A is disposed closer to the center in the direction x in the portion near the one end edge of the transparent substrate 1A. As shown in FIG. 2, the terminal portion 21A is configured by a plurality of strip-shaped portions 22A. Each of the plurality of strip portions 22 </ b> A extends in a direction perpendicular to the direction x, and is arranged in parallel along the direction X. The strip portion 22A is made of, for example, Al, Ag, Mo, or Cr. As shown in FIG. 3, the terminal portion 21 </ b> A is a portion that is joined to the flexible wiring substrate 5 via the anisotropic conductive film 4.

  The cathode electrode 2B is for supplying electrons to the organic layer, and has a pixel forming portion 23B and a terminal portion 21B. Each of the pixel forming portions 23B is configured by a strip-like portion extending in the direction x, and is made of a metal having a relatively high reflectance such as Al. The terminal portion 21B is disposed near both ends in the direction x in the portion near one end edge of the transparent substrate 1A, and is shaped so as to sandwich the terminal portion 21A. As shown in FIG. 2, the terminal portion 21 </ b> B is composed of a plurality of strip portions 22 </ b> B. Each of the plurality of strip portions 22B extends in a direction perpendicular to the direction x, and is arranged in parallel along the direction x. The strip portion 22B is made of, for example, Al, Ag, Mo, or Cr. The terminal part 21 </ b> B is a part joined to the flexible wiring substrate 5 through the anisotropic conductive film 4 similarly to the terminal part 21 </ b> A.

  The organic layer is sandwiched between intersections of the pixel formation portion 23A and the pixel formation portion 23B. This organic layer emits light of a predetermined wavelength by being supplied with holes from the anode electrode 2A and electrons from the cathode electrode 2B. Thereby, the intersection of the pixel formation portion 23A and the pixel formation portion 23B constitutes a pixel. The organic layer has a structure in which, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer are stacked.

  The dummy electrodes 3 are arranged near both end edges in the direction x in a portion near one end edge of the transparent substrate 1A. The dummy electrode 3 is used for aligning the flexible wiring substrate 5 and the transparent substrate 1A when the flexible wiring substrate 5 is bonded to the transparent substrate 1A. What are the anode electrode 2A and the cathode electrode 2B? Not conducting. As shown in FIG. 2, the dummy electrode 3 is composed of a plurality of strip portions 31. The strip portion 31 extends in a direction perpendicular to the direction x, and is formed of Al, Ag, Mo, Cr, or the like, which is the same material as the plurality of strip portions 22A and 22B.

  As shown in FIG. 2, the plurality of strip portions 22 </ b> A, 22 </ b> B, and 31 are arranged in parallel in the direction X. The plurality of strip portions 22A are arranged at a constant arrangement pitch p1. The plurality of strip portions 22B are arranged at a constant arrangement pitch p2. The plurality of strip portions 31 are arranged at a constant arrangement pitch p3. In the present embodiment, the arrangement pitch p1 is smaller than the arrangement pitch p2. The arrangement pitch p3 is not more than the arrangement pitch p1. Further, the width w1 of the belt-like portion 22A is set to be smaller than the width w2 of the belt-like portion 22B, and the width w3 of the belt-like portion 31 is set to be equal to or less than the width w2 of the belt-like portion 22A.

  The anisotropic conductive film 4 is obtained by mixing a large number of conductive fine particles in an insulating resin. The anisotropic conductive film 4 joins the flexible wiring substrate 5 to the transparent substrate 1A, and the flexible wiring substrate 5 and the anode electrode. This is for conducting 2A and the cathode electrode 2B. The anisotropic conductive film 4 is an example of the anisotropic conductive resin referred to in the present invention, and has a property of being cured by heating and pressing.

  The flexible wiring board 5 is for supplying power to the organic EL display device A from the outside and transmitting a display command signal, and includes a resin layer 51 and a wiring pattern 52. The resin layer 51 is made of polyimide resin, for example, and has flexibility.

  The wiring pattern 52 is obtained by patterning a metal film such as Cu or Al. As shown in FIGS. 3 and 4, the wiring pattern 52 has a plurality of strip-shaped portions facing the terminal portions 21 </ b> A and 21 </ b> B. These strip portions are basically arranged in parallel at the same arrangement pitch p1 as the plurality of strip portions 22A in a state before the flexible wiring board 5 is bonded to the transparent substrate 1A. As an exception, among the plurality of strips of the wiring pattern 52, those located closer to both ends in the direction x (the three strips on the left in FIG. 4) have the same arrangement pitch p3 as the plurality of strips 31 of the dummy electrode 3 Are arranged in parallel.

  A driving IC 6 is mounted on the flexible wiring board 5. The drive IC 6 performs control to display a desired image on the display area 10 by passive matrix control using the anode electrode 2A and the cathode electrode 2B in accordance with a display command transmitted from outside the machine via the flexible wiring board 5. Is.

  Next, the operation of the organic EL display device will be described.

  As shown in FIG. 4, when the flexible wiring substrate 5 is bonded to the transparent substrate 1 </ b> A, the anisotropic conductive film 4 is heated and pressed through the flexible wiring substrate 5. This is for curing the anisotropic conductive film 4. By this heating and pressurization, the flexible wiring board 5 is stretched in the direction x. For this reason, the arrangement pitch of the plurality of strip-like portions of the wiring pattern 52 becomes larger as it is located closer to both ends in the direction x. According to the present embodiment, among the plurality of belt-like portions of the wiring pattern 52, those arranged closer to the center in the direction x are hardly increased in arrangement pitch. Therefore, a plurality of narrow widths w1 arranged at a relatively small arrangement pitch p1. It overlaps well with the belt-like portion 22A. On the other hand, among the plurality of strips of the wiring pattern 52, those located closer to both ends in the direction x have a remarkable increase in the array pitch. Therefore, the plurality of strips having a thick width W2 arranged at a relatively large array pitch p2. It overlaps well with 22B. Therefore, the wiring pattern 5 of the flexible wiring board 5 can be appropriately conducted to the anode electrode 2A and the cathode electrode 2B.

  In the present embodiment, in order to display an image on the display region 10, the pixel forming portion 23B of the cathode electrode 2B is scanned at a predetermined frequency, and the pixel forming portion 23A of the anode electrode 2A is changed according to this scanning. A plurality of belt-shaped parts to be configured are selectively conducted. For this reason, the current flowing through the strip portion 22B of the cathode electrode 2B is several hundred times the current flowing through the strip portion 22A of the anode electrode 2A. Since the width w2 of the band 22B is larger than the width w1 of the band 22A, the electric resistance of the band 22B is smaller than the electric resistance of the band 22A. Therefore, it is possible to prevent a relatively large current flowing through the belt-like portion 22B from being unduly dissipated as Joule heat, thereby saving power.

  Further, when the flexible wiring board 5 is bonded to the transparent substrate 1A, the dummy electrode 3 formed on the transparent substrate 1A and the plurality of strips included in the wiring pattern 52 of the flexible wiring board 5 are positioned near both ends in the direction x. If they are overlapped with each other, the flexible wiring board 5 and the transparent substrate 1A can be accurately aligned. This alignment can be easily confirmed by visually observing that the plurality of strips 31 and the strips of the wiring pattern 52 facing the plurality of strips 31 overlap each other through the transparent substrate 1A. Of the strips of the plurality of strips 31 and the wiring pattern 52, those facing the plurality of strips 31 are arranged at an arrangement pitch p3. The arrangement pitch p3 is set to be equal to or less than the arrangement pitch p1 of the plurality of strip portions 22A arranged relatively densely. Therefore, the plurality of strip portions 22A and 22B of the anode electrode 2A and the cathode electrode 2B and the plurality of strip portions included in the wiring pattern 52 of the flexible wiring board 5 can be accurately positioned.

  The display device according to the present invention is not limited to the above-described embodiment. The specific configuration of each part of the display device according to the present invention can be modified in various ways.

  If the dummy electrode 3 is composed of a plurality of strip portions 31, it is advantageous for alignment between the flexible wiring board 5 and the transparent substrate 1A. However, the present invention is not limited to this, and consists of only one strip portion 31. Even in the configuration including the dummy electrode 3, accurate positioning can be performed if the width w3 is equal to or smaller than the width w1 of the strip portion 22A of the anode electrode 2A. The organic EL display device described above is an example of the display device according to the present invention, and the present invention can be applied to various display devices such as a liquid crystal display device.

It is a principal part top view which shows an example of the organic electroluminescence display which concerns on this invention. It is a principal part enlarged plan view which shows an example of the organic electroluminescence display which concerns on this invention. It is principal part sectional drawing in alignment with the III-III line of FIG. It is principal part sectional drawing in alignment with the IV-IV line of FIG. It is a principal part top view which shows an example of the conventional display apparatus.

Explanation of symbols

A organic EL display device p1, p2, p3 arrangement pitch w1, w2, w3 width x (parallel) direction 1A transparent substrate 1B sealing substrate 2 electrode 2A anode electrode 2B cathode electrode 3 dummy electrode 4 anisotropic conductive film 5 flexible wiring Substrate 6 drive IC
10 Display regions 21A, 21B Terminal portions 22A, 22B Strip portions 23A, 23B Pixel formation portion 31 Strip portions 51 Resin layer 52 Wiring pattern

Claims (3)

A transparent substrate;
An electrode having a terminal portion composed of a plurality of strip-shaped portions arranged in parallel on the transparent substrate;
A flexible wiring board bonded to the terminal part via an anisotropic conductive resin;
A display device comprising:
Among the plurality of strips, the one located near the center in the parallel direction has a width smaller than the width of the plurality of strips located near the end in the parallel direction. apparatus.   Among the plurality of strips, the arrangement pitch between those adjacent to each other near the center in the parallel direction is smaller than the arrangement pitch between the plurality of strips adjacent to each other near the end in the parallel direction. The display device according to claim 1. One or more additional ones that are arranged outside the plurality of strips in the arrangement direction of the plurality of strips, are made of the same material as the plurality of strips, and do not electrically belong to the electrode With a band,
3. The display device according to claim 1, wherein the additional belt-shaped portion has a width equal to or smaller than a width of the narrowest one of the plurality of belt-shaped portions.

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