JP2005346982A - Display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device having excellent display characteristics with degradation of a resistor alleviated, and a manufacturing method of the display device. <P>SOLUTION: As one mode of the device, the display device is provided with a cathode auxiliary wiring 21 arranged on a substrate 11 having a transparent conductive layer pattern 29, a plurality of metal pads 41 electrically connected to the cathode auxiliary wiring 21 and arranged on the cathode auxiliary wiring 21 so as to get in contact with the transparent conductive layer pattern 29, and an FPC 61 equipped so as to be connected with the plurality of metal pads 41 from on top of the plurality of the metal pads 41. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device and a manufacturing method thereof.

With the rapid progress of technological development in the information and communication field in recent years, great expectations are placed on a flat display replacing CRT. In particular, organic EL displays are actively studied because they are excellent in terms of high-speed response, visibility, brightness, and the like.

An organic EL device announced by Tang et al. Of Kodak Company in 1987 has a two-layer structure of organic thin films, and uses tris (8-quinolinolato) aluminum (hereinafter abbreviated as “Alq”) as a light emitting layer. Then, green light emission was generated by driving at a low voltage of 10 V or less, and a high luminance of 1000 cd / m ² was obtained (for example, see Non-Patent Document 1). The luminous efficiency was 1.5 lumen / W.

  Since then, research for rapid practical use has been advanced, and various stacked organic EL elements having about 1 to 10 organic layers sandwiched between a hole injection electrode and an electron injection electrode have been developed.

  With regard to organic EL materials, organic EL can be obtained by forming thin films of various low-molecular compounds by a method such as spin coating, ink jet, die coating, or flexographic printing, as well as a method of forming a thin film of various low-molecular compounds by vacuum deposition. A method of creating an element has been proposed.

  In addition, technical information about organic EL elements created by the “Technical Field Patent Map Creation Committee” is posted on the JPO homepage, so-called basic patents, various materials, manufacturing methods, device structures, driving methods In regard to color technology, durability improvement, applications, etc., patent reports are published and registered patents are cited and reported collectively.

  An organic EL element substrate used in an organic EL display has an anode formed on the substrate, a thin organic compound layered on the anode, and a transparent layer formed on the organic compound layer on the substrate. In this structure, the cathode is formed so as to face the anode. An organic EL element is a current-driven display element that emits light when a current is supplied to an organic compound layer disposed between an anode and a cathode. Hereinafter, a thin film of an organic compound to be laminated is referred to as an organic thin film layer. A display pixel is a portion where an anode, a plurality of organic thin film layers, and a cathode are stacked. Then, light is extracted from the transparent anode and a desired image is displayed.

  By the way, the organic EL display device uses a current drive element, and in the passive drive type organic EL display device, it is necessary to emit light instantaneously within a time when each row is selected. As a result, a large current flows into the electrode as compared with the case where a voltage-driven display element such as a liquid crystal device is used.

  Therefore, it is important to make the cathode wiring and anode wiring low resistance. As panels become larger, higher definition, and higher brightness, the resistance of these wirings will need to be further reduced, and at the same time, contacts and driving circuits between these wirings and auxiliary wiring Lowering the resistance between the connection terminal and the auxiliary wiring has been an issue. In this regard, there is a disclosed prior art regarding cathode auxiliary wiring connected to the cathode wiring of the organic EL display device (for example, Patent Document 1).

  In this prior art, a transparent electrode material is used for the drive circuit connection terminal, and the cathode material and the cathode auxiliary wiring material are the same. In this case, if the cathode surface or the cathode auxiliary wiring surface is not oxidized before the connection between the cathode material and the cathode auxiliary wiring material, the possibility of solving the problem of contact resistance between the cathode and the cathode auxiliary wiring is increased.

  Further, an organic electroluminescence display element that attempts to eliminate an increase in contact resistance of a metal electrode due to baking at the time of manufacture is disclosed (for example, Patent Document 2). Therefore, a barrier layer is formed on the surface layer of the extraction electrode provided on the transparent substrate, and the extraction electrode is brought into contact with the metal electrode laminated on the transparent substrate via the organic light emitting layer via the barrier layer.

  The extraction electrode is formed of a metallic conductive material such as Cr, Al, Cu, Ag, Au, Pt, Pd, Ni, Mo, Ta, Ti, W, C, Fe, In, Ag-Mn, and Zn. The barrier layer is formed of a refractory metal, a noble metal, an oxide, a nitride, or an oxynitride having good heat resistance and alteration.

  Therefore, it is described that the contact resistance between the extraction electrode and the metal electrode is kept low even when heating is performed at the time of forming the interlayer insulating film or the like, and the driving can be performed at a low voltage. Further, when the extraction electrode is formed via the adhesion improving layer, the adhesion of the extraction electrode to the transparent substrate is improved, and a good electrical connection between the extraction electrode and the metal electrode is maintained.

  On the other hand, since the anode wiring is usually formed of a transparent conductive film, a metal oxide film such as ITO (Indium Tin Oxides) is used. Since such a metal oxide film generally has a higher specific resistance than a metal, it is difficult to reduce the wiring resistance. Accordingly, it is possible to reduce the resistance by providing an anode auxiliary wiring made of a metal material outside the display region.

  The structure of the organic EL display device provided with the anode auxiliary wiring will be described with reference to FIG. FIG. 7 is a top view showing a configuration of an organic EL element substrate used in the organic EL display device.

  A plurality of anode wirings 1 are formed of a transparent conductive film. On the substrate end side of the anode wiring 1, anode auxiliary wiring 26 is formed corresponding to each anode wiring 1. The anode auxiliary wiring 26 is patterned so as to be superimposed on the anode wiring 1. Thereby, the anode wiring 1 and the anode auxiliary wiring 26 are connected. Since the anode auxiliary wiring 26 is formed of a metal film having a specific resistance lower than that of the anode wiring 1, the wiring resistance can be reduced. At this time, a pattern corresponding to the cathode auxiliary wiring 21 is simultaneously formed.

  Al or Al alloy having a low specific resistance is mainly used for the anode auxiliary wiring 26 and the cathode auxiliary wiring 21. Further, for example, a refractory metal film is used as a barrier layer in the upper layer and the lower layer. The refractory metal film under the Al layer is formed to improve the contact resistance with the transparent conductive film. The refractory metal film on the upper layer of Al is formed in order to prevent the contact resistance from deteriorating due to the deterioration of Al due to oxidation or the like in a later step.

  An insulating film 22 having an opening 23 corresponding to the pixel electrode is formed from above. For example, a photosensitive polyimide resin is used for the insulating film 22. In the step of forming the opening 23, a contact hole 25 for connecting the cathode auxiliary wiring 21 and the cathode wiring 5 is formed. And in order to isolate | separate the cathode wiring 5, the partition 10 of a reverse taper structure is formed. An organic thin film layer (not shown) is formed thereon, and a cathode wiring 5 is formed thereon. The cathode wiring 5 is separated by the partition wall 10 and formed so as to intersect the anode wiring 1. In the opening 23 provided at the position where the cathode wiring 5 and the anode wiring 1 intersect, a current flows through the organic thin film layer to emit light.

  The cathode auxiliary wiring 21 and the anode auxiliary wiring 26 are used as, for example, metal pads for connecting to an FPC or the like. For example, an anisotropic conductive film (hereinafter referred to as ACF) is attached on the cathode auxiliary wiring 21 and the anode auxiliary wiring 26, and further, FPC or the like is overlapped on the ACF and bonded. Accordingly, the cathode auxiliary wiring 21 or the anode auxiliary wiring 26 which is a metal pad is connected to the FPC or the like, and current can be supplied to the anode wiring 1. Since the cathode auxiliary wiring 21 and the anode auxiliary wiring 26 are formed of metal, wiring resistance and connection resistance with external wiring are reduced as compared with the case where a transparent conductive film formed of a metal oxide such as ITO is used as a metal pad. can do.

  However, the configuration in which the anode auxiliary wiring 26 or the cathode auxiliary wiring 21 made of metal is used as a metal pad for connecting to an external wiring has the following problems. The cathode auxiliary wiring 21 and anode auxiliary wiring 26 made of metal may corrode during or after the manufacturing process. When corrosion of the metal occurs, the corroded portion gradually spreads with time, and the connection resistance and wiring resistance with external wiring such as FPC are deteriorated. Therefore, the resistance of only the wiring in which metal corrosion has occurred is deteriorated, resulting in display unevenness. In particular, when the whole or most of the portion connected to the external wiring is corroded, the connection resistance is significantly deteriorated. This corrosion of the metal occurs due to impurities contained in an external wiring such as an FPC, and gradually spreads from the occurrence location to the entire metal pad. As described above, the conventional organic EL display device has a problem that the connection resistance is deteriorated and the display characteristics may be deteriorated.

JP 11-317292 A JP 2001-351778 A Appl. Phys. Lett. , 51, 913 (1987)

  As described above, the conventional organic EL display device has a problem that display characteristics may be deteriorated due to deterioration of resistance.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide a display device in which deterioration of display characteristics due to deterioration of resistance is reduced.

  The display device according to the first aspect of the present invention includes a conductive metal oxide layer (for example, cathode auxiliary wiring in the embodiment of the present invention) on a substrate (for example, the substrate 11 in the embodiment of the present invention). 21) and a plurality of metal pads (for example, metal pad 41 in an embodiment of the present invention) are laminated, and the plurality of metal pads are disposed on the surface opposite to the substrate of the metal oxide layer, and the metal oxide layer And the plurality of metal pads are conductively connected, and external wiring (for example, FPC 62 in the embodiment of the present invention) is conductively connected from the side opposite to the substrate surface of the metal pad. Thereby, it is possible to reduce display characteristic deterioration due to resistance deterioration.

  A display device according to a second aspect of the present invention is the display device described above, wherein a plurality of metal pads are arranged along the longitudinal direction of the metal oxide layer. Thereby, it is possible to reduce display characteristic deterioration due to resistance deterioration.

  In the display device according to the third aspect of the present invention, in the display device described above, a plurality of metal pads are juxtaposed in the width direction of the metal oxide layer, thereby reducing display characteristics due to resistance deterioration. Can be reduced.

  A display device according to a fourth aspect of the present invention is the display device described above, wherein a metal layer is further provided above the metal oxide layer and closer to the display region than the end of the external wiring, The metal layer is formed separately from the metal pad. Thereby, the resistance of the wiring can be reduced.

  A display device according to a fifth aspect of the present invention is the display device described above, wherein the metal pad and the metal layer are the same process layer. Accordingly, it is possible to provide a display device in which the deterioration of display characteristics due to the deterioration of resistance is reduced with a simple configuration.

  A display device according to a sixth aspect of the present invention is the display device described above, wherein the metal pad includes at least one layer of Al, Al alloy, Mo, Mo alloy, Ag, or Ag alloy.

  A method for manufacturing a display device according to a seventh aspect of the present invention includes: forming a conductive metal oxide layer on a substrate; and forming a plurality of metal pads on the metal oxide layer. And a step of conductively connecting external wiring from the side opposite to the substrate surface of the plurality of metal pads. Thereby, it is possible to reduce display characteristic deterioration due to resistance deterioration.

  According to an eighth aspect of the present invention, there is provided a display device manufacturing method comprising: forming a metal film on the metal oxide layer; and patterning the metal film to form a metal pad in the manufacturing method described above. And a step of performing. As a result, a display device can be manufactured with a simple configuration and reduced deterioration of display characteristics due to resistance deterioration.

  The display device manufacturing method according to the ninth aspect of the present invention is the above-described manufacturing method, in the step of patterning the metal film, without removing the metal film located closer to the display region than the end of the external wiring. The metal layer is formed by leaving. Thereby, wiring resistance can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which improved the weather resistance and corrosion resistance of the electrode in a terminal part, and improved the long-term reliability performance as an electronic device can be provided.

  Hereinafter, embodiments to which the present invention can be applied will be described. The following description is to describe the embodiment of the present invention, and the present invention is not limited to the following embodiment. For clarity of explanation, the following description is omitted and simplified as appropriate. Further, those skilled in the art will be able to easily change, add, and convert each element of the following embodiments within the scope of the present invention. In addition, what attached | subjected the same code | symbol in each figure has shown the same element, and abbreviate | omits description suitably.

  An element substrate on which an organic EL light emitting element of the organic EL display device according to the present embodiment is formed will be described with reference to FIG. FIG. 1 is a plan view showing a configuration of an element substrate of an organic EL display device. 1 is anode wiring, 5 is cathode wiring, 10 is a partition, 11 is a substrate, 21 is cathode auxiliary wiring, 22 is an insulating film, 23 is an opening, 25 is a contact hole, 26 is anode auxiliary wiring, and 27 is auxiliary wiring. , 28 are metal patterns, and 29 is a transparent conductive film pattern. In the present invention, the cathode auxiliary wiring 21 has a two-layer structure of a transparent conductive film pattern 29 and a metal pattern 28 provided thereon. Reference numeral 40 denotes a terminal portion of the cathode auxiliary wiring 21.

  A plurality of anode wirings 1 are formed on the substrate 11 so as to be in contact with the surface of the substrate 11. The plurality of anode wirings 1 are formed in parallel. An anode auxiliary wiring 26 corresponding to each anode wiring 1 is formed on the anode wiring 1 on the substrate end side. On the substrate end side, the anode auxiliary wiring 26 functions as a metal pad for connecting to external wiring such as FPC (Flexible Printed Circuit board) and TCP (Tape Career Package). That is, an anisotropic conductive film (hereinafter referred to as ACF) is bonded onto the anode auxiliary wiring 26, and further, external wiring is superimposed on the ACF and pressure bonded. Thereby, the external wiring and the anode auxiliary wiring 26 which is a metal pad are connected. A current can be supplied from the drive circuit to the anode wiring 1 through the external wiring. A transparent conductive film pattern 29 is formed in the same layer as the anode wiring 1. A metal pattern 28 is formed in the same layer as the anode auxiliary wiring 26.

  The metal pattern 28 is formed corresponding to the number of the cathode wirings 5. The metal pattern 28 is separated in a direction perpendicular to the cathode wiring 5. A portion of the metal pattern 28 provided on the display area side is an auxiliary wiring portion 27. On the other hand, a portion of the metal pattern 28 provided on the substrate end side becomes a terminal portion 40 for connection to external wiring. The terminal portion 40 is formed with a metal pad for connecting to an external wiring such as FPC or TCP. The configuration around the terminal portion 40 will be described later.

  The anode wiring 1 and the transparent conductive film pattern 29 are formed of a transparent conductive film such as ITO. The anode auxiliary wiring 26 and the metal pattern 28 are formed of a metal film having a multilayer structure or a single layer structure. For example, a laminated metal film to be the anode auxiliary wiring 26 and the metal pattern 28 is formed in the order of the Mo layer, the Al layer, and the Mo layer from the bottom. A cathode wiring 5 is disposed so as to cross the anode wiring 1, and a cathode auxiliary wiring 21 is formed on the substrate end side of the cathode wiring 5. An insulating film 22 is formed on the substrate on which the anode auxiliary wiring 1, the anode auxiliary wiring 26, and the cathode auxiliary wiring 21 are formed. The film thickness of the insulating film 22 is 0.7 μm, for example. In the insulating film 22, an opening 23 is provided at a position where the anode wiring 1 and the cathode wiring 5 intersect (that is, a position serving as a display pixel).

  A contact hole 25 is formed in the insulating film 22 to connect the cathode auxiliary wiring 21 and the cathode wiring 5 to the outside of the display area. In the contact hole 25, the cathode wiring 5 and the cathode auxiliary wiring 21 are connected. In the terminal portion 40 disposed on the substrate end side of the cathode auxiliary wiring 21, the cathode auxiliary wiring 21 is connected to the external wiring and a drive circuit connected to the external wiring through the ACF. Thereby, an electric current can be sent through the organic thin film layer sandwiched between the anode wiring 1 and the cathode wiring 5 in the opening 23, and the organic thin film layer emits light. The area where the opening 23 is provided becomes a display area, and a desired image can be displayed.

  A plurality of organic thin film layers (organic compound layers) and the cathode wiring 5 are sequentially stacked on the insulating film 22. Accordingly, the organic thin film layer is sandwiched between the cathode wiring 5 and the anode wiring 1. However, illustration of the organic thin film layer is omitted in FIG. In addition, before the organic thin film layer is formed, a separation structure (hereinafter referred to as a partition wall 10) that separates adjacent cathode wirings is provided. The barrier rib 10 is formed in a desired pattern before the cathode wiring 5 is formed by vapor deposition or the like. For example, as shown in FIG. 1, a plurality of partition walls 10 orthogonal to the anode wiring 1 are formed on the anode wiring 1 in order to form a plurality of cathode wirings 5 orthogonal to the anode wiring 1.

  The partition wall 10 preferably has an inverted taper structure. That is, it is preferable that the cross-section is formed so as to be separated from the substrate 11. Thereby, the side wall and the rising portion of the partition wall 10 are shadowed by vapor deposition, and the cathode wiring 5 can be divided. The partition wall 10 can be formed with a height of 3.4 μm and a width of 10 μm, for example.

  After the partition wall 10 is formed, an organic thin film layer is formed by a vapor deposition method or a coating method. Further, a metal is deposited on the organic thin film layer. The deposited metal film is divided by a partition wall 10 having a reverse taper structure to form a plurality of cathode wirings 5. The metal film to be the cathode wiring 5 is deposited using a mask so as not to be formed outside the partition wall 10. The organic EL element substrate has the above-described configuration.

  The element substrate and the counter substrate on which the water catching material is formed are arranged to face each other. The element substrate and the counter substrate are bonded to each other with a sealing material provided on the opposing surface, and the space in which the organic EL element is provided is sealed. And an external wiring is connected to the connection terminal of wiring, and an organic EL display panel is formed by mounting a drive circuit.

  Next, the structure of the terminal part 40 provided in the board | substrate edge side is demonstrated using FIG. FIG. 2A is an enlarged top view including the periphery of the terminal portion 40, focusing on one anode wiring 1. FIG. 2B is an enlarged sectional view showing the terminal portion 40. 41 is a metal pad, 42 is a cutting part, 51 is a counter substrate, 53 is a sealing material for bonding the counter substrate 51 and the substrate 11, 61 is an ACF, 62 is an FPC, 63 is a conductive layer provided on the FPC 62, Reference numeral 66 denotes a cover resin for preventing moisture and the like from entering. In FIG. 2, reference numeral 65 denotes an end of the ACF on the display area side. In FIG. 2, the left side is the display area side, and the right side is the substrate end side.

  In the present embodiment, the cathode auxiliary wiring 21 has a laminated structure of a transparent conductive film pattern 29 and a metal pattern 28 provided on the transparent conductive film pattern 29. As shown in FIG. 2, a plurality of metal pads 41 for connecting to the FPC 62 are provided in the terminal portion 40. That is, the terminal portion 40 is provided with a cutting portion 42 for cutting the metal pattern 28 perpendicular to the wiring direction, and the metal pattern 28 is separated to form a plurality of metal pads 41. The plurality of metal pads 41 are arranged in a line along the wiring direction.

  Since the plurality of metal pads 41 are directly provided on the transparent conductive film pattern 29, they are electrically connected to the transparent conductive film pattern 29. By forming a plurality of metal pads 41 separated from each other in this way, even if corrosion occurs, it is possible to prevent the corrosion site from spreading. That is, even when corrosion occurs in one metal pad 41, the metal pattern 28 is separated from the adjacent metal pad 41, thereby preventing the metal corrosion from spreading to the adjacent metal pad 41. it can. Thereby, deterioration of resistance based on expansion of metal corrosion can be reduced. Therefore, even if the metal pad 41 is corroded, the electrical characteristics of the wiring due to the deterioration of resistance can be maintained.

  In the example shown in FIG. 2, nine metal pads 41 are arranged along the direction in which the wiring is provided. The metal pad 41 is formed on a region where the transparent conductive film pattern 29 is exposed, and is directly disposed on the transparent conductive film pattern 29. An ACF 61 is pressure-bonded on the metal pad 41. It is preferable that the metal pad 41 be formed in such a size that it can be sufficiently adhered to the ACF 61 to obtain a sufficient connection resistance.

  Here, the metal pad 41 is formed with a width of 200 μm × 200 μm. The size of the metal pad 41 is set, for example, in consideration of the size of the conductive particles contained in the ACF 61 and the adhesion with the ACF 61. For example, it is preferable to make the metal pad sufficiently larger than the size of the conductive particles contained in ACF61. Further, if the area of the metal pad 41 is too large, the resistance deterioration due to the expansion of corrosion becomes large.

  In general, the specific resistance of a metal film is lower than the specific resistance of a transparent conductive film, and current flows easily. Therefore, by reducing the width of the cut portion 42, the resistance of the entire wiring can be reduced. That is, the resistance of the cathode auxiliary wiring 21 can be reduced and the display quality can be improved. Moreover, it can prevent that the adjacent metal pad 41 contacts by forming the width | variety of the cutting part 42 more than patterning precision. Here, the cutting portion 42 is formed with a thickness of 10 μm from the patterning accuracy of the metal pattern to reduce the wiring resistance. That is, a gap of 10 μm is provided between adjacent metal pads 41. In the cut portion 42, the transparent conductive film pattern 29 is exposed in the uppermost layer. The width of the cut portion 42 is preferably 10 μm or less in order to reduce resistance degradation.

  In FIG. 2, nine metal pads 41 are arranged in a row along the direction of the cathode wiring 5. The nine metal pads 41 are provided in parallel. An end portion of the FPC 62 is provided on the third metal pad 41 from the left. That is, the FPC 62 is attached so that the end on the display area side is disposed on the third metal pad 41 from the left. Therefore, there are two more metal pads inside the end of the FPC 62 on the display area side.

  An end portion 65 of the ACF is disposed on the metal pad 41 that is closest to the display area. A conductive layer 63 is provided on the substrate side of the FPC 62. The conductive layer 63 is provided in contact with the ACF 61 from above. The current of the metal pad 41 is supplied through the conductive layer 63. The metal pattern 28 is provided with a cover resin 66 in an area where the transparent conductive film pattern 29 is exposed. The cover resin 66 is a resin having low water permeability and prevents moisture and the like from entering the cathode auxiliary wiring 21 and the sealed space.

  An auxiliary wiring portion 27 is formed inside the metal pad 41 on the most display area side. The auxiliary wiring portion 27 and the metal pad 41 are formed as part of the metal pattern. That is, the auxiliary wiring part 27 and the metal pad 41 are formed by the same process. The auxiliary wiring portion 27 is provided so as to extend to the inside of the sealing material. That is, the sealing material 53 is arranged on the auxiliary wiring portion 27. Note that the auxiliary wiring portion 27 may be disposed inside the sealing material 53. The auxiliary wiring portion 27 is formed along the direction of the cathode wiring 5 to the inside of the contact hole 25 shown in FIG. Since the specific resistance of the metal pattern 28 is lower than the specific resistance of the transparent conductive film pattern 29, the wiring resistance of the cathode auxiliary wiring 21 can be reduced by providing the auxiliary wiring portion 27 along the wiring direction.

  Furthermore, the metal pad 41 and the auxiliary wiring portion 27 are arranged separately, and the auxiliary wiring portion 27 is provided on the inner side of the FPC 62, whereby corrosion caused by impurities contained in the FPC 62 is caused to the auxiliary wiring portion 27. Can be prevented. Thereby, deterioration of wiring resistance can be prevented. Furthermore, by providing the display area side of the end portion 65 of the ACF, it is possible to prevent the corrosion caused by the impurities contained in the ACF 65 from occurring on the auxiliary wiring portion 27. Thereby, deterioration of wiring resistance can be prevented.

  A drive circuit (not shown) is connected to the conductive layer 63 of the FPC 62. Then, current from the drive circuit is supplied to the cathode auxiliary wiring 21 through the metal pad 41. In FIG. 2, the FPC 62 is used as the external wiring, but it goes without saying that the TCP on which the drive circuit is mounted may be used. Of course, the number, size, and the like of the above-described metal pads are examples, and are not limited to those described above. Furthermore, various arrangements are conceivable for the plurality of metal pads. Examples of arrangement of a plurality of metal pads are shown in FIGS. 3, 4 and 5, respectively. 3, 4 and 5 are top views schematically showing examples of arrangement of metal pads.

  In the arrangement shown in FIG. 3, the metal pad 41 is further separated in a direction parallel to the wiring with respect to the arrangement shown in FIG. Thereby, the area of one metal pad 41 can be reduced, and even if corrosion occurs, the area where corrosion spreads can be narrowed. Further, in the arrangement shown in FIG. 4, the auxiliary wiring portion 27 is thinned in the metal pad. The metal pads 41 are arranged on both sides of the thin portion of the auxiliary wiring portion 27, respectively. Further, in the arrangement shown in FIG. 5, the auxiliary wiring portion 27 is formed in a U-shape. And the metal pad 41 is arrange | positioned inside the U-shaped part. Thus, the plurality of metal pads 41 can be arranged in various ways.

  In the above description, the plurality of metal pads 41 are provided on the terminal portion of the cathode auxiliary wiring 21, but a plurality of metal pads may be formed on the anode auxiliary wiring 26. That is, by forming a plurality of metal pads on the substrate end side of the anode auxiliary wiring 26, it is possible to prevent resistance deterioration on the anode wiring side.

  Next, the manufacturing method of the organic EL display concerning a present Example is demonstrated using FIG. FIG. 6 is a flowchart showing an example of a method for manufacturing an organic EL display according to this example.

  First, an ITO film to be the anode wiring 1 and the transparent conductive film pattern 29 is formed on the substrate 11 (step S101). As the substrate 11, for example, a transparent substrate such as a glass substrate is used. As the glass substrate, for example, soda lime glass can be used. The thickness of the ITO film is usually 50 to 200 nm. More preferably, it is 100-150 nm. Typically, it is an ITO film having a thickness of 150 nm manufactured by a DC sputtering method. In addition to the above, the ITO film can be generally produced by physical vapor deposition (PVD) such as vacuum deposition or ion plating. In this description, an ITO film is used. Of course, other than ITO, a conductive film made of a transparent metal oxide such as IZO may be used.

  ITO can be formed on the entire surface of the glass substrate with good uniformity by sputtering or vapor deposition. The ITO film is patterned by photolithography and etching to form the anode wiring 1 (step S102). A phenol novolac resin is used as the resist, and exposure development is performed. Etching may be either wet etching or dry etching. For example, ITO can be patterned using a mixed aqueous solution of hydrochloric acid and nitric acid. As the resist stripping material, for example, monoethanolamine can be used. Thereby, the anode wiring 1 and the transparent conductive film pattern 29 are formed.

  Next, a laminated metal film of Mo layer, Al layer, and Mo layer is formed by DC sputtering (step S103). These can be continuously formed. In addition, the laminated metal film may be produced by a physical vapor deposition method (PVD) such as a vacuum deposition method or an ion plating method, or a plating method such as electrolytic plating or electroless plating.

  The thicknesses of the upper and lower Mo layers are usually 50 to 200 nm, and the thickness of the Al layer is usually 200 to 400 nm. When Mo alloy is used instead of Mo, corrosion resistance is improved. As the Mo alloy, it is preferable to use binary Mo-W, Mo-Nb, Mo-V, Mo-Ta, or the like.

  An Al alloy can be used instead of Al. When pure Al is applied as a layer made of either Al or Al alloy, it is preferable to set the film forming temperature to 100 ° C. or lower in order to suppress generation of hillocks. When using an Al alloy, it is preferable to use Al—Nd because the resistance can be reduced during curing. Furthermore, Al—Si, ternary Al—Si—Cu, and the like are also applicable. Here, a combination of three layers of Mo, Al, and Mo is used.

  Thereafter, the laminated metal film is patterned (step S104). For example, the resist is patterned by a photolithography process, the laminated metal film is etched, and the resist is peeled off. Any known resist may be used as long as it does not contradict the spirit of the present invention.

  For the etching, for example, an etching solution made of a mixed aqueous solution of phosphoric acid, acetic acid and nitric acid can be used. Any known stripping agent may be used for stripping the resist as long as it does not violate the gist of the present invention.

  The Mo layer and the Al layer can be collectively etched with this etching solution. Thereby, the anode auxiliary wiring 26 is formed. Moreover, the metal pattern 28 is formed by this process. By forming the anode auxiliary wiring 26 and the metal pattern 28 in the same process, the manufacturing process can be simplified. Therefore, the cathode auxiliary wiring 21 is patterned in these steps. Note that a silica coat film may be formed on the entire surface of the substrate before the ITO film forming step (step S101).

  Next, the insulating film 22 is formed on the surface of the substrate 11 provided with the anode wiring 1, the metal pattern 28, and the anode auxiliary wiring 26 (step S105). For example, a photosensitive polyimide solution is applied by spin coating. The thickness of the insulating film 22 may be set to 0.7 μm, for example. The insulating film 22 is patterned (step S106). For example, the insulating film layer is patterned by a photolithography process and a developing process, and then cured, and the insulating film at a position to be a display pixel is removed to provide an opening 23. The intersection of the cathode wiring 5 and the anode wiring 1 formed in step S109 described later becomes a display pixel.

  At the same time, a contact hole 25 for connecting the cathode wiring 5 and the cathode auxiliary wiring 21 is formed. For example, the opening corresponding to the pixel is formed with a size of about 300 μm × 300 μm. The contact hole 25 between the cathode wiring 5 and the cathode auxiliary wiring 21 is formed with, for example, 200 μm × 200 μm or less. In the case where the pixel opening is about 300 μm × 300 μm, it is preferable that the contact forming portion between the cathode and the auxiliary wiring is 200 μm × 200 μm or less because it does not affect the size of the entire device.

  Subsequently, the partition 10 is formed on the surface of the insulating film (polyimide layer) so that the 64 cathode wirings 5 can be separated and arranged (step S107). In FIG. 1, the number of wires is reduced and schematically shown. The partition 10 is formed by applying a photosensitive resin such as a novolac resin or an acrylic resin film on the upper layer of the insulating film. For example, a photosensitive resin is spin-coated, patterned by a photolithography process, and then photoreacted to form cathode barrier ribs. It is desirable to use a negative type photosensitive resin so that the cathode partition has an inversely tapered structure.

  When a negative photosensitive resin is used, when light is irradiated from above, the photoreaction becomes insufficient at deeper locations. As a result, when viewed from above, the cross-sectional area of the cured portion has a structure that is narrower on the lower side than on the upper side. This means that it has an inverted taper structure. With such a structure, the cathodes can be separated from each other because the portions that are shaded when viewed from the vapor deposition source during vapor deposition of the cathodes do not reach the vapor deposition.

  Further, in order to modify the surface of the ITO layer in the opening 23, oxygen plasma or ultraviolet light may be irradiated. For example, using a parallel plate RF plasma (high frequency plasma) apparatus, oxygen plasma irradiation is performed to modify the surface of the ITO film.

  Thereafter, an organic thin film layer is stacked (step S108). First, a metal mask having an opening is attached to a glass substrate. At this time, the opening of the metal mask and the position where the organic thin film layer should be provided are arranged so as to overlap each other, and the 50 μm space is attached between the metal mask and the glass substrate. Then, an ethyl benzoate solution in which 0.5% (percentage by mass) of polyvinyl carbazole is dissolved is applied by a mask spray method. Then, the solution is concentrated and dried to form a hole injection layer.

  Subsequently, α-NPD (N, N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine) is deposited on the upper layer of the hole injection layer to form a hole transport layer having a thickness of 40 nm. Form. Further, Alq (tris (8-hydroxynato) aluminum) serving as the host compound of the light emitting layer and coumarin 6 serving as the fluorescent dye of the guest compound are simultaneously vapor deposited on the upper layer to form a light emitting layer having a thickness of 60 nm. Form. Subsequently, LiF is deposited on the light emitting layer to form a cathode interface layer having a thickness of 0.5 nm.

  Thereafter, a metal material such as aluminum is vapor-deposited to form a cathode wiring with a film thickness of 100 nm (step S109). As a result, the aluminum film is separated by the partition walls, and the cathode wiring 5 that intersects the anode wiring 1 can be formed between the partition walls. For example, 64 cathode wirings 5 are formed corresponding to the number of pixels. An organic EL element substrate is formed by these steps.

  Next, in order to seal the organic EL light emitting element formed by the above-mentioned process, a process for manufacturing a sealing counter substrate will be described. First. A glass substrate different from the element substrate is prepared. The glass substrate is processed to form a water catching material storage for storing the water catching material. The water catching material storage part applies a resist to the glass substrate and exposes a part of the substrate by exposure and development. The exposed part is formed by etching to form a water catching material storage part.

  After a water catching material such as calcium oxide is disposed in the water catching material storage portion, the two substrates are stacked and bonded. Specifically, a sealing material is applied to the surface of the counter substrate on which the water catching material storage unit is provided using a dispenser. For example, an epoxy-based ultraviolet curable resin can be used as the sealing material. The sealing material is applied to the entire outer periphery of the region facing the organic EL element. After the two substrates are aligned and face each other, the sealing material is cured by irradiating ultraviolet rays, and the substrates are bonded to each other. Thereafter, heat treatment is performed for 1 hour in a clean oven at 80 ° C. in order to further accelerate the curing of the sealing material. As a result, the sealing material and the pair of substrates separate the substrate where the organic EL element is present from the outside of the substrate. By disposing the water catching material, it is possible to prevent the organic EL element from being deteriorated due to moisture remaining or entering the sealed space.

  Unnecessary portions near the outer periphery of the substrate are cut and removed, a signal electrode driver is connected to the anode auxiliary wiring 26, and a scanning electrode driver is connected to the cathode auxiliary wiring 21 in the same manner. A terminal portion connected to each auxiliary wiring is formed at the substrate end. An anisotropic conductive film (ACF) is attached to the terminal portion, and a TCP (Tape Carrier Package) provided with an FPC or a drive circuit is connected. A part of the substrate auxiliary side of the anode auxiliary wiring 26 whose uppermost layer is a Mo layer serves as a terminal portion, and the contact resistance can be reduced.

  Specifically, ACF is temporarily crimped to the terminal portion. An ACF uses Hitachi Chemical's Anisolm 7106U. The pressure during the temporary pressure bonding is 80 ° C., the pressure pressure is 1.0 MPa, and the pressure bonding time is 5 seconds. Next, a TCP with a built-in FPC or drive circuit is pressure-bonded to the terminal portion. The crimping temperature during the final crimping is 170 degrees, the crimping pressure is 2.0 MPa, and the crimping time is 20 seconds. Thereby, a drive circuit is mounted. This organic EL display panel is attached to the housing, and the organic EL display device is completed. In addition, the above-mentioned process is an example of a manufacturing process, and is not limited thereto, and may be used for a display device other than an organic EL display device. Needless to say, the present invention is not limited to a passive matrix display device, and can also be used for an active matrix display device.

It is a top view which shows an example of a structure of the organic electroluminescence display concerning this invention. It is a figure which shows the structure of a terminal part periphery in an example of the organic electroluminescent display apparatus concerning this invention. It is a flowchart which shows the manufacturing process of the organic electroluminescence display of this invention. In the organic EL display device according to the present invention, it is a top view showing an arrangement example of metal pads. In the organic EL display device according to the present invention, it is a top view showing an arrangement example of metal pads. In the organic EL display device according to the present invention, it is a top view showing an arrangement example of metal pads. It is a top view which shows the structure of the organic electroluminescent display apparatus of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Anode wiring 5 Cathode wiring 10 Partition 11 Board | substrate 21 Cathode auxiliary wiring 22 Insulating film 23 Opening part 25 Contact hole 26 Anode auxiliary wiring 27 Auxiliary wiring part 28 Metal pattern 29 Transparent conductive layer pattern 40 Terminal part 41 Metal pad 42 Cutting part 51 Opposite Substrate 53 Sealing material 61 ACF
62 FPC
63 conductive layer 65 end of ACF 66 cover resin 100 organic EL element substrate

Claims (9)

On the substrate, a conductive metal oxide layer and a plurality of metal pads are laminated,
The plurality of metal pads are disposed on the surface of the metal oxide layer opposite to the substrate;
The metal oxide layer and the plurality of metal pads are conductively connected to each other,
A display device in which external wiring is conductively connected from the side opposite to the substrate side of the metal pad.   The display device according to claim 1, wherein a plurality of metal pads are arranged along a longitudinal method of the metal oxide layer. The display device according to claim 1, wherein a plurality of metal pads are juxtaposed in the width direction of the metal oxide layer. A metal layer is further provided above the metal oxide layer and closer to the display region than the end of the external wiring,
The display device according to claim 1, wherein the metal layer is disposed separately from a metal pad.   The display device according to claim 1, wherein the metal pad and the metal layer are the same process layer.   6. The display device according to claim 1, wherein the metal pad includes at least one layer of Al, Al alloy, Mo, Mo alloy, Ag, or Ag alloy. Forming a conductive metal oxide layer on a substrate;
Forming a plurality of metal pads on the metal oxide layer;
And a step of conductively connecting external wiring from the side opposite to the substrate surface of the plurality of metal pads. Forming a metal film on the metal oxide layer;
The method for manufacturing a display device according to claim 7, further comprising: patterning the metal film to form a metal pad.   9. The method of manufacturing a display device according to claim 8, wherein in the step of patterning the metal film, the metal layer is formed by leaving the metal film positioned on the display region side with respect to the end portion of the external wiring without being removed.

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