JP2006278343A - Manufacturing method of luminescent display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a yield by repairing defects by a short-circuit of a first electrode (transparent electrode 102) and a second electrode (metal electrode 104) of a luminescent display. <P>SOLUTION: When a defect pixel of a non-luminescent pixel, a luminescent defect pixel or the like by short-circuiting a transparent electrode 102 and a metal electrode 104 is generated, only a part B corresponding to the defect part among the transparent electrode 102 corresponding to the defect pixel and the metal electrode 104 corresponding to a region crossing the metal electrode 104 is removed and repaired, so that, electric current is made to flow between the facing transparent electrode 102 through an organic layer 103 by the metal electrode 104 of a remaining part A, its pixel and pixels scanned afterwards are made to emit light. Elimination of a corresponding part of the metal electrode 104 is processed by irradiating a laser beam. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light-emitting display suitable using organic electroluminescence (organic EL) as a light-emitting element.

  2. Description of the Related Art Conventionally, an organic EL element that can emit light by passing a current through a phosphor formed on a glass plate or a translucent organic film is known. FIG. 4 shows a schematic cross-sectional structure of a light emitting display using an organic EL as a light emitting element. As shown in FIG. 4, the conventional light-emitting display is formed by laminating a transparent electrode (layer) 302, an organic layer 303, and a metal electrode (layer) 304 on a transparent substrate 301 in this order.

  In general, an organic EL element is considered to be a capacitive light emitting element that is equivalently expressed by a circuit resistance component, a capacitance component, and a light emitting component. Therefore, when a voltage is applied between the transparent electrode 302 and the metal electrode 304, a charge corresponding to the electric capacity of the element flows into the electrode as a displacement current and is accumulated. Subsequently, when a certain voltage (barrier voltage) is exceeded, a current starts to flow through the organic layer 303 composed of the organic EL element via the electrodes 301 and 304, and light emission starts in proportion to this current.

  FIG. 5 shows an example of the arrangement of transparent electrodes and metal electrodes in a simple matrix drive type light emitting display. As shown in FIG. 5, a light emitting display using the above-described organic EL element as a light emitting element is formed of a plurality of parallel stripes made of ITO or the like and arranged at predetermined intervals on a transparent glass substrate 101. A transparent electrode 102, a light emitting portion 103 made of an organic layer, and a plurality of parallel striped metal electrodes 104 which are orthogonal to the transparent electrode 102 and arranged at a predetermined interval are sequentially stacked. Further, a protective film (not shown) is formed over the entire surface of the substrate 101 on which the metal electrode 104 and the organic layer 103 are formed to prevent moisture.

  In addition, the light emitting display includes a light emitting pixel in which one region of the organic layer 103 in which each of the transparent electrode 102 and the metal electrode 104 facing each other and crossing each other faces and intersects is formed as a unit. By arranging the number of pixels in a matrix, a simple matrix drive type light emitting display is formed. In the light emitting display thus formed, a voltage is appropriately applied between the transparent electrode 102 and the metal electrode 104 corresponding to the pixel by a driving source that scans and drives each transparent electrode 102 and the metal electrode 104, and the corresponding pixel. A current flows through the organic layer 103 to emit light.

  By the way, in manufacturing such a light emitting display, as the area of the display screen increases, the probability of the occurrence of scratches or the adhesion of particles increases. This has been a major factor in yield deterioration during manufacturing.

  That is, as shown in FIG. 4, when the scratch 10 is generated on the transparent electrode 302 or the particles 20 on the transparent electrode 302 are attached, the organic layer 303 is formed on that portion of the surface of the transparent electrode 302. It will be insufficient. In addition, the defect 30 may occur in the organic layer 303 for some reason. As a result, the metal electrode layer 304 is directly formed on the transparent electrode layer 302 in the portion where the organic layer 303 is not sufficiently formed, and the anode of the transparent electrode layer 302 and the cathode of the metal electrode layer 304 are short-circuited. was there.

  Even if the short circuit does not occur, the organic layer 303 between the transparent electrode 302 and the metal electrode 304 is extremely thinly formed, and the light emission current is concentrated on that portion, so that the current hardly flows in the peripheral portion. In other words, the pixel does not emit light. This problem is one of the biggest causes of defects at the time of manufacturing, and greatly reduces the yield.

  Therefore, although measures have been taken by carefully cleaning the substrate, it is not possible to take time for cleaning, and it is impossible to completely remove particles, scratches on the transparent electrode 302, or irregularities on the surface of the transparent electrode 302 by cleaning. there were.

  It should be noted that there is no prior art document information to be disclosed because there is no document known invention related to the present invention that the applicant knows at the time of filing the patent.

  As described above, in a light-emitting display using an organic EL element as a light-emitting element, if there is a concave-shaped scratch on the transparent electrode 302 or dust is attached, film formation on that part becomes insufficient, and the transparent display A thin organic layer 303 is formed on the electrode 302. In particular, in the case of film formation by vapor deposition, when a convex portion is formed by dust or the like, the side surface of the convex portion is difficult to be vapor deposited, and sufficient film formation is not performed. In addition, since the cathode and the anode are close to each other in the thin portion of the organic layer 303, the current is likely to be concentrated, causing a short circuit between the cathode and the anode. Even if the short circuit does not occur, there is a problem that the light emission current is concentrated in the thinly formed portion, and as a result, the current does not easily flow in the peripheral portion and the pixel does not emit light.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a light-emitting display and a method for manufacturing the same that repair defects caused by short-circuiting between a transparent electrode and a metal electrode to improve yield.

  The invention of claim 1 is a method of manufacturing a light-emitting display in which a first electrode, an organic layer composed of an organic electroluminescent element, and a second electrode are sequentially laminated on a substrate. A step of forming one electrode, a step of sequentially stacking the organic layer and the second electrode, and a step of sealing the organic electroluminescent element with a sealing cover after the second electrode is stacked on the organic layer. After the sealing formation step and after the sealing formation step, when there is a defective portion where the organic layer is insufficiently formed in the light emitting portion, light is emitted only to the corresponding portion of the second electrode corresponding to the defective portion. And removing only the portion irradiated with this light.

  The invention of claim 2 is a method of manufacturing a light-emitting display in which a first electrode, an organic layer composed of an organic electroluminescent element, and a second electrode are sequentially laminated on a substrate. Forming a layer of one electrode; sequentially stacking the organic layer and the second electrode; and laminating the organic electroluminescent element with an opaque sealing cover after the second electrode is stacked on the organic layer. A sealing formation step that stops, and after the sealing formation step, when there is a defective portion where the organic layer is insufficiently formed in the light emitting portion, a corresponding portion of the second electrode corresponding to the defective portion And irradiating only the light, and removing only the portion irradiated with the light.

  Invention of Claim 3 is a manufacturing method of the light emission display of Claim 1 or 2, Comprising: The process of removing only the part irradiated with the said light irradiates the said light from the said substrate side. And

  The invention of claim 4 is a method for manufacturing a light-emitting display in which a first electrode, an organic layer composed of an organic electroluminescent element, and a second electrode are sequentially laminated on a substrate. A step of forming a layer of one electrode, a step of sequentially laminating the organic layer and the second electrode, a sealing step of sealing the organic electroluminescent element with a sealing cover, and the formation of the organic layer on the light emitting portion When there is a defective portion that is insufficient, light having a wavelength that is transparent to the sealing cover is emitted only from the sealing cover side to a corresponding portion of the second electrode corresponding to the defective portion. Irradiating and removing only the portion irradiated with this light.

  The present invention corresponds to a region where a transparent electrode and a metal electrode corresponding to a defective pixel intersect even when a defective pixel such as a pixel that does not emit light due to a short-circuit between the transparent electrode and the metal electrode or a defective light emitting pixel occurs. By repairing the metal electrode by deleting only the part corresponding to the defective part of the metal electrode, a current is passed between the transparent electrodes facing each other through the organic layer by the remaining metal electrode, and the pixel and the subsequent scanning are performed. This causes the pixel to emit light. This makes it possible to design a light-emitting display that can withstand practical use even if there are some defective pixels, and can contribute to an improvement in yield by defect repair.

  FIG. 1 is a schematic cross-sectional view of a light emitting display according to an embodiment of the present invention. As shown in FIG. 1, the light-emitting display of the present invention has a plurality of second electrodes intersecting a plurality of transparent electrodes 102, an organic layer 103, and the transparent electrodes 102 made of ITO or the like serving as a first electrode on a glass transparent substrate 101. A metal electrode 104 to be an electrode is sequentially deposited and formed. A light emitting part as an optical display using an organic EL element is formed by the transparent electrode 102 and the metal electrode 104 facing each other with the organic layer 103 interposed therebetween, and each of the transparent electrode 102 and the metal electrode 104 faces each other. One pixel is formed with the light emitting portion of the intersecting region intersecting as one unit.

  Here, the defect pixel includes the scratch 10, the particle 20, and other organic layer defects 30 similar to those in FIG. 4, but a corresponding portion B of the defect portion of the metal electrode 104 is deleted, and the remaining portion around the defect portion is removed. Part A is left. By doing so, the concentration of current is eliminated, and current is passed to the periphery to promote normal light emission of the pixel.

  Focusing on the fact that the defective portion is sufficiently smaller than one pixel, only the defective portion of the metal electrode 104 is deleted in the defective pixel, and the organic layer 103 is formed by the remaining portion A of the metal electrode 104 excluding the defective portion of the defective pixel. The yield is improved by repairing by passing a current between the transparent electrodes 102 facing each other and causing the defective pixel to emit light. Depending on the method of deleting the metal electrode 104, the organic layer 103 or the transparent electrode 102 of the defective portion A may be deleted at the same time, but there is no particular problem.

  For the metal electrode 104, for example, an Al—Li alloy having a small work function such as aluminum, magnesium, indium, copper, or an alloy thereof is used. The transparent electrode 102 can be made of a conductive material having a high work function such as ITO or gold. Here, when gold is used as an electrode material, the electrode is translucent.

  FIG. 2 is a diagram showing a manufacturing process of the simple matrix driving type light emitting display shown in FIG. 2A, first, an electrode material such as ITO is vapor-deposited on the transparent substrate 101, and a plurality of transparent electrode layers 102 are formed according to patterning based on a photolithography method.

  Next, in FIG. 2B, on the transparent substrate 101 on which the transparent electrode 102 is formed, for example, TPD, Alq3, and the like are sequentially stacked as an organic material to form a light emitting unit composed of the organic layer 103. In FIG. 2C, when the metal electrode layer 104 is formed, light emitting pixels having a unit corresponding to a region of the organic layer where each transparent electrode 102 and the metal electrode 104 intersect and sandwich each other are arranged in a matrix. It is formed. It is assumed that the scratches 10 on the transparent electrode 102 or the particles 20 on the transparent electrode 102 are attached as in the conventional example shown in FIG.

  In the simple matrix driving type light emitting display formed as described above, a voltage is applied between the transparent electrode 102 and the metal electrode 104 corresponding to each pixel as appropriate by a driving source that scans and drives each transparent electrode 102 and the metal electrode 104. Then, charges are sent to the light emitting portion 103 of each pixel to emit light. Therefore, a driving source is applied so that all the light emitting pixels of the light emitting display emit light simultaneously, and in this state, defective pixels such as defective light emitting pixels and pixels that do not emit light are confirmed. Then, the defective pixel is repaired.

  As shown in FIG. 2D, the repair is performed by irradiating a part of the unit pixel region corresponding to the light emitting region inherent to the defective pixel with laser light. That is, a part of the metal electrode 104 facing the light emitting region is removed by laser irradiation. Here, the positioning of the laser spot is performed by measuring the coordinates of the light emitting region (pixel) in advance, and further confirming the defective portion by visual observation using a microscope, and positioning the laser spot.

  As a result, when the defective portion is sufficiently smaller than one pixel, only the defective portion of the metal electrode 104 is deleted from the defective pixel, and the remaining metal electrode 104 excluding the defective portion of the defective pixel faces through the organic layer 103. A current can be passed between the transparent electrodes 102 and the pixels can emit light. In the above example, the laser beam is irradiated from the metal electrode 104 side, but the defective portion of the metal electrode 104 can be deleted by irradiating the laser beam from the transparent substrate 101 side. However, when the transmittance of the transparent substrate 101 to the laser is low, it is preferable to irradiate from the metal electrode 104 side.

  In this way, when the defective portion of the metal electrode 104 is deleted, as shown in FIG. 2E, a protective film 105 is laminated on the entire surface of the transparent substrate 101, whereby a simple matrix driving type light emitting display is obtained. Is formed.

  In the above embodiment, the protective film 105 is formed. For example, as shown in FIG. 3, a sealing cover 106 is attached so as to cover the transparent electrode 102, the organic layer 103, and the metal electrode layer 104. You may make it seal around the 101. FIG. In this case, the defective portion of the metal electrode 104 can be deleted after the sealing cover 106 is attached. That is, when the sealing cover 106 is made of metal or the like and is opaque, the laser is irradiated from the transparent substrate 101 side as indicated by a circled number 1. When the sealing cover 106 is made of glass or the like and is transparent, the laser can be irradiated from either the transparent substrate 101 side with the circled number 1 or the sealing cover 106 side with the circled number 2.

  Needless to say, the sealing cover 106 may be further attached to the laminated protective film 105.

  Note that in the above-described embodiment of the present invention, only a simple matrix driving type light-emitting display composed of at least a plurality of transparent electrodes 102 orthogonal to the organic layer 103 and an organic EL element formed by a plurality of metal electrodes 104 is used. However, the present invention is not limited to this, and any material used for the array of light emitting pixels and the light emitting portion may be used as long as a plurality of light emitting pixels are formed by crossing a plurality of pairs of electrodes. Absent.

It is a figure which shows the general | schematic layer structure cross section of the light emission display in this invention embodiment. It is a figure which shows the manufacturing process of the light emission display in embodiment of this invention. It is a figure which shows the state which used the sealing cover with the light emission display in this invention embodiment. It is a figure which shows schematic sectional structure of the conventional light emission display. It is a figure which shows an example of the arrangement | sequence of the transparent electrode of a simple matrix drive type light emitting display using the organic EL element in the past, and a metal electrode.

Explanation of symbols

101 ... Substrate 102 ... Transparent electrode (first electrode)
103 ... Organic layer (light emitting part)
104 ... Metal electrode (second electrode)
105 ... Protective film layer

Claims (4)

A method of manufacturing a light-emitting display in which a first electrode, an organic layer composed of an organic electroluminescent element, and a second electrode are sequentially stacked on a substrate,
Forming a first electrode layer on the substrate;
Sequentially stacking the organic layer and the second electrode;
A sealing forming step of sealing the organic electroluminescent element with a sealing cover after laminating the second electrode on the organic layer;
After the sealing formation step, when there is a defective portion where the organic layer is not sufficiently formed on the light emitting portion, only the corresponding portion of the second electrode corresponding to the defective portion is irradiated with light. Removing only the irradiated part;
A method for manufacturing a light emitting display, comprising: A method of manufacturing a light-emitting display in which a first electrode, an organic layer composed of an organic electroluminescent element, and a second electrode are sequentially stacked on a substrate,
Forming a first electrode layer on the substrate;
Sequentially stacking the organic layer and the second electrode;
A sealing formation step of sealing the organic electroluminescent element with an opaque sealing cover after laminating the second electrode on the organic layer;
After the sealing formation step, when there is a defective portion where the organic layer is not sufficiently formed on the light emitting portion, only the corresponding portion of the second electrode corresponding to the defective portion is irradiated with light. Removing only the irradiated part;
A method for manufacturing a light emitting display, comprising:   The method of manufacturing a light emitting display according to claim 1, wherein the step of removing only the portion irradiated with the light irradiates the light from the substrate side. A method of manufacturing a light-emitting display in which a first electrode, an organic layer composed of an organic electroluminescent element, and a second electrode are sequentially stacked on a substrate,
Forming a first electrode layer on the substrate;
Sequentially stacking the organic layer and the second electrode;
A sealing step of sealing the organic electroluminescent element with a sealing cover;
When there is a defective portion in which the organic layer is not sufficiently formed in the light emitting portion, light having a wavelength that is transparent to the sealing cover is transmitted from the sealing cover side to the defective portion. And a step of irradiating only a corresponding portion of the two electrodes with light and removing only the portion irradiated with the light.

Images