JP2006215227A - Method for improving light emitting device and light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device in which a defective pixel can be efficiently improved without exerting adverse influence on normal pixels. <P>SOLUTION: The basic pattern of resistance wiring L3 consisting of poly silicon is formed by a first process from a source region 32 of a driving transistor Qd formed on a transparent substrate 2. The resistance wiring L3 is electrically connected to the anode E1 of an organic EL element through an relay electrode 20. Then, a part or all of the resistance wiring L3 is fused by irradiating it with a laser beam in a second process. Thus, since the resistance wiring L3 whose area is small as compared with that of the anode electrode E1 and a cathode electrode E2 is fused, cutting is completed in a short period of time, and cutting efficiency is good. As a result, the productivity of an organic EL display 1 can be improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for improving a light emitting device and a light emitting device.

  Conventionally, an electro-optical element of a light emitting device, for example, an organic EL element of an organic electroluminescence display device (organic EL display device), a drive transistor is supplied with a current value based on gradation data and is relative to the gradation data. It emits light with brightness. Therefore, when the drive transistor has a defect in the electrical characteristics in the manufacturing process, it does not emit light with the brightness based on the gradation data, and therefore inspection is performed before shipping the product. As one of this type of inspection, there is a bright spot inspection for inspecting each pixel for defects. This bright spot inspection is, for example, a defect inspection in which an organic EL element is short-circuited due to a failure of a drive transistor or the like, and a defective pixel in which the organic EL element emits light with the highest luminance is searched.

When a defective pixel is found, it is important to improve the defect by improving the defect, and various improvement methods have been proposed (for example, Patent Document 1). In the improvement method of Patent Document 1, a part of at least one of the first electrode (anode) or the second electrode (cathode) of a pixel (organic EL element) in which a display defect has occurred is lost (blown) with laser light. This improves display defects.
JP 2003-233329 A

  However, in Patent Document 1, since the first electrode (anode) is formed of a light-transmitting film, the first electrode (anode) is transmitted even when irradiated with laser light, is difficult to be removed, has a poor improvement work efficiency, and is organic EL. It adversely affects the organic EL layer of the device. Further, since the second electrode is formed of a light-shielding metal film and is easy to remove, the light-shielding metal particles may scatter and adversely affect other normal pixels. Further, since the first and second electrodes depend on the pixel region, and the area thereof is large, it takes time to remove the part, and the improvement work efficiency is poor.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a light emitting device improvement method and a light emitting device that can efficiently improve defective pixels without adversely affecting normal pixels. Is to provide.

  The light emitting device improvement method of the present invention is a light emitting device in which a light emitting element and a switching element are formed on a substrate, and the switching element is turned on to supply power from a power supply line to the light emitting element to cause the light emitting element to emit light. In the improvement method, at least one of the wiring formed between the power supply line and the switching element or the wiring formed between the light emitting element and the switching element is a resistance wiring, and the process of forming the resistance wiring is It includes at least a first process for forming a basic mold and a second process for further processing the basic mold.

  According to the method for improving a light-emitting device of the present invention, the basic shape of the resistance wiring has a smaller area (line width) than the electrode of the light-emitting element. Can do.

In this method for improving a light emitting device, the substrate may be a transparent substrate, and the resistance value of the resistance wiring formed by the first step may be adjusted by the second step.

According to this method for improving a light emitting device, the basic type of the resistance wiring is processed in the second step, and the resistance value is adjusted.
In a method of improving the light-emitting device, the second step is a laser beam irradiation step, and fusing some or all of the resistance wiring by irradiating a laser beam to the resistance wire through the substrate The resistance value may be adjusted.

According to this method for improving a light emitting device, the resistance value can be adjusted by irradiating the resistance wiring with laser light from the surface opposite to the element forming surface of the transparent substrate to improve the luminance of the light emitting element.
In this method of improving a light emitting device, the resistance wiring is a plurality of resistance wiring elements connected in parallel, and each resistance wiring element is appropriately selected and cut by irradiating laser light to obtain a resistance value. You may make it adjust.

  According to this method for improving a light-emitting device, the resistance value can be accurately adjusted and the luminance of the light-emitting element can be accurately adjusted simply by irradiating and cutting the resistance wiring element of the resistance wiring with a laser beam. .

In this method for improving a light emitting device, the switching element may be a drive transistor.
According to this method for improving a light emitting device, the current supplied to the light emitting element via the drive transistor is adjusted.

In this method for improving a light emitting device, the resistance wiring may be a polysilicon film.
According to this method for improving a light emitting device, since the polysilicon film easily absorbs laser light, the resistance value can be adjusted in a short time to improve the luminance of the light emitting element.

In the method for improving the light emitting device, the light emitting element may be an electroluminescence element or a light emitting diode.
According to this method for improving a light-emitting device, the luminance of a defective electroluminescent element or light-emitting diode can be improved in a short time as a result of a bright spot inspection of a light-emitting device composed of an electroluminescent element or light-emitting diode.

  In this method for improving a light-emitting device, the electroluminescent element has a light-emitting layer and a hole transport layer formed between an anode and a cathode made of an organic material, and an anode and a drive transistor formed on the hole transport layer side. Between the two, a resistance wiring may be formed.

  According to this method for improving a light-emitting device, as a result of a bright spot inspection of a light-emitting device composed of an electroluminescent element, the luminance of a defective pixel can be increased only by adjusting the resistance value of a resistance wiring with a laser beam for a defective electroluminescent element. It can be improved in a short time.

  In the light emitting device of the present invention, a light emitting element and a switching element are formed on a substrate, the switching element is turned on in response to a selection signal, and a plurality of pixels that emit light by supplying power from a power line to the light emitting element. In the light emitting device having, at least one of the wiring formed between the power supply line and the switching element or the wiring formed between the light emitting element and the switching element for each of the pixels is a resistance wiring, With respect to the specific pixel in each of the pixels, a part of or all of the resistance wiring for the specific pixel is melted with a laser beam so that the resistance value is adjusted.

According to the light-emitting device of the present invention, the resistance wiring easily absorbs laser light and has a smaller area (line width) than the electrode of the light-emitting element, so that the resistance value can be adjusted in a short time and the luminance of the light-emitting element can be increased. Can be improved. As a result, yield and production efficiency can be improved.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic plan view showing an organic electroluminescence display device (organic EL display device) as a light emitting device.

  As shown in FIG. 1, the organic EL display device 1 includes a transparent substrate 2. The transparent substrate 2 is a non-alkali glass substrate formed in a square shape, and a rectangular element formation region 3 is formed on one side surface (surface in FIG. 1: element formation surface 2a as a pattern formation surface). Has been.

  In the element formation region 3, a plurality of data lines Lx extending in the vertical direction (column direction) are formed at predetermined intervals. The plurality of data lines Lx are electrically connected to the data line driving circuit 4 disposed on the lower side of the transparent substrate 2, respectively. The data line driving circuit 4 generates a data signal based on display data (gradation data) supplied from an external device (not shown), and outputs the data signal to the corresponding data line Lx at a predetermined timing. ing.

  Further, in the element formation region 3, as with the data lines Lx, a plurality of power supply lines Lv extending in the column direction are provided alongside the data lines Lx with a predetermined interval. The plurality of power supply lines Lv are electrically connected to a common power supply line Lvc formed below the element formation region 3, respectively, and supply drive power generated by a power supply voltage generation circuit (not shown) to each power supply line Lv. It is like that.

  Further, in the element formation region 3, a plurality of scanning lines Ly extending in a direction (row direction) orthogonal to the data lines Lx and the power supply lines Lv are formed at a predetermined interval. Each scanning line Ly is electrically connected to a scanning line driving circuit 5 formed on the left side of the transparent substrate 2. The scanning line drive circuit 5 selectively drives a predetermined scanning line Ly from the plurality of scanning lines Ly at a predetermined timing based on a scanning control signal supplied from a control circuit (not shown), and scans the scanning line Ly. A signal is output.

  A plurality of pixels 6 arranged in a matrix by being connected to the corresponding data line Lx, power supply line Lv, and scanning line Ly are formed at positions where the data lines Lx and the scanning lines Ly intersect. In the pixel 6, as shown in FIG. 1, a control element formation region 7 and a light emitting element formation region 8 are partitioned.

  FIG. 2 shows an electric circuit showing the pixel circuit 10 formed in the pixel 6. In FIG. 2, the pixel circuit 10 includes a drive transistor Qd as a switching element, a switching transistor Qsw, a holding capacitor Cs, and an organic electroluminescence element (organic EL element) 11.

  In the present embodiment, the drive transistor Qd and the switching transistor Qsw are each an n-type thin film transistor (TFT), and are formed in the light emitting element formation region 8. The organic EL element 11 is an electroluminescence element in which a light emitting layer and a hole transport layer are made of an organic material.

The drive transistor Qd has its gate terminal connected to the source terminal of the switching transistor Qsw. The switching transistor Qsw has a drain terminal connected to the data line Lx and a gate terminal connected to the scanning line Ly. Further, one end of the holding capacitor Cs is connected to the gate terminal of the driving transistor Qd. The other end of the holding capacitor Cs is connected to the power supply line Lv and is supplied with the drive voltage Vdd. The source terminal of the drive transistor Qd is connected to the anode E1 of the organic EL element 11, and the cathode E2 of the organic EL element 11 is grounded. The drain terminal of the drive transistor Qd is connected to the power supply line Lv and is supplied with the drive voltage Vdd.

Next, the operation of the pixel circuit 10 configured as described above will be briefly described.
First, when the selection signal Sy is output from the scanning line driving circuit 5 via the scanning line Ly for a predetermined period, the switching transistor Qsw is turned on for a predetermined period, and the data signal Dx is transmitted from the data line driving circuit 4 via the data line Lx. Is supplied.

  Then, the data signal Dx is supplied to the holding capacitor Cs via the switching transistor Qsw. The holding capacitor Cs accumulates and holds a charge amount corresponding to the data signal Dx. Further, the potential of the gate terminal of the drive transistor Qd is pushed up by the data signal, the drive current Id corresponding to the data signal flows through the drain / source of the drive transistor Qd, and the drive current Id is supplied to the organic EL element 11. The drive current Id has a value relative to the amount of charge corresponding to the data signal Dx stored in the holding capacitor Cs.

  That is, the drive transistor Qd is turned on in response to the data signal Dx, and the conduction state is maintained and the drive current Id is supplied to the organic EL element 11. Then, the organic EL element 11 emits light at this timing.

Next, the configuration of the pixel 6 described above will be described below. FIG. 3 is a schematic plan view showing the layout of the pixels 6.
As shown in FIG. 3, a control element formation region 7 is formed below each pixel 6, and a switching transistor Qsw, a drive transistor Qd, and a holding capacitor Cs are provided in the control element formation region 7. Yes.

  The switching transistor Qsw is a polysilicon thin film transistor (TFT) having a gate electrode connected to the scanning line Ly via the gate wiring G1, and a source region connected to the gate electrode of the driving transistor Qd via the gate wiring G2. The drain region is connected to the data line Lx. The source region of the switching transistor Qsw is connected to one end (lower electrode) of the holding capacitor Cs via the wiring L1 branched from the gate wiring G2, and the other end (upper electrode) of the holding capacitor Cs is connected to the wiring L2. Are electrically connected to the power line Lv.

  Similarly to the switching transistor Qsw, the driving transistor Qd is a polysilicon TFT, the gate electrode is connected to the source region of the switching transistor Qsw via the gate wiring G2, and the drain region is connected to the power supply line Lv via the wiring L2. Has been. The source region of the drive transistor Qd is electrically connected to the anode E1 of the organic EL element 11 via the relay electrode 20 via the wiring L3. The anode E1 is formed in the light emitting element formation region 8, and an organic EL layer 21 constituting the organic EL element 11 is formed on the anode E1.

FIG. 4 is a longitudinal sectional view of a main part for explaining the structure of the drive transistor Qd and the organic EL element 11 and the electrical wiring structure thereof.
In FIG. 4, the driving transistor Qd has a semiconductor film having a channel region 31, a source region 32, and a drain region 33 formed on the element formation surface 2 a of the transparent substrate 2. In addition, a part of the semiconductor film has the wiring L 3 extending from the source region 32. If the thickness of the wiring L3 of the semiconductor film is constant, it is possible to make a resistance wiring having a predetermined resistance value (the wiring L3 is referred to as the resistance wiring L3) by adjusting the width and length of the semiconductor wiring L3. Of course, the resistance value may be adjusted by changing the thickness of the semiconductor film or changing the doping concentration. That is, the resistance value R is as follows. The resistivity of the wiring L3 of the semiconductor film is ρ, the length is D, the width is W, and the thickness is t.
R = ρ · D / (W · t)
It becomes.

  Next, a manufacturing method as a first step for forming a resistance wiring will be briefly described. A semiconductor film is formed on the transparent substrate 2. As the semiconductor film, polysilicon is preferable because it has an appropriate resistance value of several KΩ / □, but other amorphous silicon, continuous grain boundary silicon, or the like may be used. As a forming method, for example, amorphous silicon is deposited by a low temperature plasma CVD method and then crystallized by a laser using an excimer laser or the like. However, other techniques such as spin coating and vapor deposition can be used. After the semiconductor film is formed, patterning is performed using a known photolithography method or the like so as to obtain a necessary resistance value. Note that a photolithography step can be omitted when a pattern is formed by a droplet discharge method after the semiconductor film is formed.

  A gate electrode 35 is formed on the upper side of the semiconductor film with a gate insulating film 34 interposed therebetween. The gate electrode 35 is a low resistance metal film such as tantalum or aluminum, and is electrically connected to the drain of the switching transistor Qsw and one end of the holding capacitor Cs via the gate wiring G2 as shown in FIG. . As shown in FIG. 4, the gate electrode 35 is electrically insulated by a transparent first interlayer insulating film 36 deposited on the gate insulating film 34.

  The drain region 33 is electrically connected to the wiring L2 through a contact hole penetrating the first interlayer insulating film 36, and is electrically connected to the other end of the holding capacitor Cs and the power supply line Lv. The resistance wiring L3 is electrically connected to the relay electrode 20 through a contact hole that penetrates the first interlayer insulating film. The wiring L2 and the relay electrode 20 are electrically insulated by a transparent second interlayer insulating film 37 deposited on the first interlayer insulating film 36.

  On the upper side of the second interlayer insulating film 37, an anode E1 as a transparent electrode is formed. The anode E1 is a transparent conductive film having optical transparency, and is formed of an ITO (Indium Tin Oxide) film. One end of the anode E1 is electrically connected to the relay electrode 20 through a contact hole that penetrates the second interlayer insulating film 37.

On the upper side of the anode E1, an insulating film 38 and a partition wall layer 39 for insulating the anodes E1 from each other are formed. The insulating film 38 is made of silicon dioxide (SiO ₂ ). The partition layer 39 is made of an acrylic photosensitive resin, a polyimide photosensitive resin, or the like. In the insulating film 38 and the partition wall layer 39, at a substantially central position of the anode E1, an accommodation hole 40 that opens upward in a circular arc shape is formed. Then, by forming the accommodation hole 40 in the partition wall layer 39, the partition wall 41 surrounding the upper surface of the anode E1 is formed.

  In this embodiment, the organic electroluminescence layer (organic EL layer) 21 is formed in a region surrounded by the partition walls 41. The organic EL layer 21 is an organic compound layer composed of two layers, a hole transport layer 21a and a light emitting layer 21b.

On the upper side of the organic EL layer 21, a cathode E2 made of a metal film having light reflectivity such as aluminum is formed. The cathode E2 is formed so as to cover the entire surface of the element formation region 3 on the element formation surface 2a side, and is shared by each pixel 6 to supply a common potential to each light emitting element formation region 8. In the present embodiment, the anode E1, the organic EL layer 21, and the cathode E2 constitute an organic electroluminescence element (organic EL element 11) as a light emitting element.

  When the drive current Id corresponding to the data signal Dx is supplied to the anode E1, the organic EL layer 21 (light emitting layer 21b) emits light with a luminance corresponding to the drive current Id. At this time, light emitted from the organic EL layer 21 toward the cathode E2 side (upper side in FIG. 4) is reflected by the cathode E2. Therefore, most of the light emitted from the organic EL layer 21 passes through the anode E1, the interlayer insulating films 37 and 36, and the transparent substrate 2, and outward from the back surface (display surface 2b) side of the transparent substrate 2. It is emitted toward. That is, an image based on the data signal Dx is displayed on the display surface 2 b of the organic EL display device 1.

  An adhesive layer (not shown) made of an epoxy resin or the like is formed on the upper side of the cathode E2 (organic EL element 11), and a sealing substrate (not shown) that covers the element formation region 3 is attached via the adhesive layer. Yes. The sealing substrate is a non-alkali glass substrate and prevents oxidation of each organic EL element 11 and various wirings Lx, Ly, Lv, Lvc and the like.

  Next, a method for adjusting the resistance value of the resistance wiring of the organic EL display device 1 configured as described above will be described. Now, when the organic EL display device 1 is formed up to the state shown in FIG. 4, a luminance inspection is performed. This bright spot inspection is a defect inspection in which the organic EL element 11 is short-circuited due to, for example, a defect of the drive transistor Qd and the pixel 6 having a bright spot defect that emits light with the highest luminance regardless of the gradation data. is there. When a pixel 6 (specific pixel) having a bright spot defect is found, the pixel 6 is darkened to make the defect inconspicuous.

  The darkening of the pixel 6 is caused by a large value of the driving current Id flowing through the organic EL element 11, and thus the driving current Id is cut off. In the present embodiment, the resistance wiring L3 is melted so that the drive current Id does not flow through the organic EL element 11 regardless of the state of the drive transistor Qd. The fusing of the resistance wiring L3 is performed by irradiating the resistance wiring L3 with laser light. The process of adjusting the resistance value by irradiating the resistance wiring using this laser light (laser light irradiation process) is called a second process. At this time, as shown in FIG. 4, the laser beam is irradiated from the back surface (display surface 2b) side of the transparent substrate 2 toward the resistance wiring L3. Since the basic resistance wiring L3 is formed of a polysilicon film, the basic resistance wiring L3 is easily melted, that is, cut (processed) easily by absorbing the energy of the laser beam. In addition, since the laser light is irradiated from the back surface (display surface 2b) side of the transparent substrate 2 close to the resistance wiring L3, the resistance wiring L3 can be cut with little energy loss and high energy efficiency. Furthermore, particles generated when the resistance wiring L3 is melted are not scattered around the resistance wiring L3 by being surrounded by the transparent substrate 2, the first interlayer insulating film 36, and the like, and thus adversely affect other pixels 6. Never give.

Next, effects of the present embodiment configured as described above will be described below.
(1) According to the above embodiment, the resistance wiring L3 formed between the drive transistor Qd and the organic EL element 11 is cut by irradiating the laser beam. Therefore, since the resistance wiring L3 having a smaller area than the anode E1 and the cathode E2 is fused, the cutting is completed in a short time and the cutting efficiency is good. As a result, the productivity of the organic EL display device 1 can be improved.

  (2) According to the above embodiment, since the resistance wiring L3 is made of polysilicon, the energy absorption efficiency of the laser light is better than that of the anode E1 made of ITO. . As a result, the productivity of the organic EL display device 1 can be improved.

(3) According to the above embodiment, since the laser beam is irradiated from the back surface side of the transparent substrate 2 close to the resistance wiring L3 through the transparent substrate 2, the resistance wiring L3 has low energy loss and high energy efficiency. Can be cut in a short time. As a result, the productivity of the organic EL display device 1 can be improved.

(4) According to the above embodiment, since the resistance wiring L3 surrounded by the transparent substrate 2, the first interlayer insulating film 36, and the like is cut around the resistance wiring L3, particles generated by fusing of the resistance wiring L3 are other The other pixels 6 are not scattered and the other pixels 6 are not adversely affected. (Second Embodiment)
Next, a second embodiment of the present invention will be described. This embodiment is different from the first embodiment only in whether or not the resistance wiring L3 is completely cut in the second step, and only the difference will be described.

In the present embodiment, the resistance value of the resistance wiring 13 can be adjusted by cutting only a part of the resistance wiring L3. In addition, when some of the organic EL elements 11 in which the variation in luminance between the light emitting elements is caused by the characteristic variation of the drive transistor Qd and the organic EL element 11 are improved in order to reduce the emission luminance, the resistance wiring L3 is appropriately set. The organic EL element 11 can be adjusted to a desired luminance by cutting the width to reduce the drive current Id.
(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first or second embodiment only in the shape of the resistance wiring L3 made of the polysilicon film, and only the difference will be described.

FIG. 5 is a schematic plan view for explaining the layout of the pixel 6 of this embodiment. In FIG. 5, a part L3a having a narrow line width is formed in a part of the resistance wiring L3 extending from the source region of the driving transistor Qd. And the part L3a was irradiated with the laser beam, and the one part or all part was cut | disconnected. Therefore, in addition to the effects of the first or second embodiment, the cutting efficiency can be further improved.
(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described with reference to FIG. This embodiment is different from the first embodiment only in the shape of the resistance wiring L3 made of a polysilicon film, and only the difference will be described.

FIG. 6 is a schematic plan view for explaining the layout of the pixel 6 of the present embodiment. In FIG. 6, the resistance wiring L3 extending from the source region of the drive transistor Qd is composed of a plurality of resistance wiring elements Lb, and the plurality of resistance wiring elements Lb are formed to be connected in parallel. Then, by selecting an appropriate number of resistance wiring elements Lb and cutting the selected number of resistance wiring elements Lb, it is possible to adjust the resistance value of the entire resistance wiring L3. That is, if all the resistive wiring elements Lb are cut with laser light, the same effect as in the first embodiment can be obtained. In addition, when some of the organic EL elements 11 in which the variation in luminance between the light emitting elements is caused by the characteristic variation of the drive transistor Qd and the organic EL element 11 are improved in order to reduce the emission luminance, the resistance wiring L3 is appropriately set. The organic EL element 11 can be adjusted to a desired luminance by cutting the resistance wiring elements Lb by the number to reduce the drive current Id.
(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described. This embodiment is different from the fourth embodiment only in the wiring width of the resistance wiring element Lb, and only the differences will be described.

FIG. 9 is a schematic plan view for explaining the layout of the pixel 6 of the present embodiment.
In the fourth embodiment, the wiring width of each resistance wiring element Lb is the same. However, in the fifth embodiment of the present invention, each resistance wiring element Lb is given a weight by changing the line width as shown in FIG. May be. For example, the line width of the wiring element Lb1 is a, the line width of the wiring element Lb2 is 2a that is twice the wiring element Lb1, and the line width of the wiring element Lb3 is 4a that is four times that of the wiring element Lb1. As a result, the resistance level of the entire adjustable resistance line L3 is 2 ⁿ (2 to the power of n). By cutting only the appropriate resistance wiring elements and the number, it is possible to adjust the drive current Id more accurately.

In addition, you may change the said embodiment as follows.
In the above embodiment, the resistance wiring L3 is formed of polysilicon. However, the present invention is not limited to this, and may be formed of amorphous silicon, continuous grain boundary silicon, or the like.
In the above-described embodiment, the organic EL display device 1 is embodied as a so-called bottom emission type, but the present invention is not limited to this and may be applied to a top emission type organic EL display device.
In the above embodiment, the laser beam is irradiated from the back surface side of the transparent substrate 2 through the transparent substrate 2, but the laser beam may be irradiated from the element forming surface 2 a side of the transparent substrate 2. In this case, the cathode E2 is preferably a transparent electrode as in the top emission type.
In the above embodiment, at least the cathode E2 is formed, and improvement is performed by irradiating the resistance wiring L3 with laser light based on the result of the luminance inspection. In the stage where the driving transistor Qd of each pixel 6 is formed before the organic EL layer 21 of each pixel 6 is formed, the driving transistor Qd of each pixel 6 is inspected to find a defective driving transistor Qd. At this point, the improvement may be made by irradiating the resistance wiring L3 with laser light. In this case, laser light may be irradiated from the back surface side of the transparent substrate 2 through the transparent substrate 2, or laser light may be irradiated from the element forming surface 2a side of the transparent substrate 2 to improve. .
In the above embodiment, the resistance wiring L3 formed between the driving transistor Qd and the organic EL element 11 is cut by irradiating the laser beam. However, the present invention is not limited to this, and the driving transistor Qd and the power supply line Lv are not limited thereto. The wiring L2 connecting the two may be a resistance wiring, and the driving current Id may be adjusted by irradiating the wiring L2 with laser light.
In the above embodiment, the resistance value of the resistance wiring is adjusted by irradiating the laser beam, but the present invention is not limited to this.
In the above embodiment, the driving transistor Qd is an n-type thin film transistor (TFT). However, the driving transistor Qd may be a p-type thin film transistor (TFT).
In the above embodiment, the pixel circuit 10 that causes the organic EL element 11 to emit light is configured by a pixel circuit including two transistors, that is, a drive transistor Qd and a switching transistor Qsw as shown in FIG. is not.

  For example, a first transistor Q1 connected between the gate and drain of the drive transistor Qd (conductivity type is p-type) and a second transistor connected between the drive transistor Qd and the organic EL element 11 shown in FIG. The present invention may be embodied in an organic EL display device having the pixel circuit 10 provided with the transistor Q2. In the pixel circuit 10 of FIG. 7, when the selection signal Sy is output for a predetermined period, the switching transistor Qsw and the first transistor Q1 are turned on, and the data signal Dx is written to the holding capacitor Cs. When the writing of the data signal Dx is completed, the second transistor Q2 is turned on for an integral period (light emission period) by the control signal Sc so that the organic EL element 11 emits light. Also in the pixel circuit 10 configured in this way, the wiring portion L11 that connects the source of the driving transistor Qd and the power supply line Lv, the wiring portion L12 that connects the driving transistor Qd and the second transistor Q2, and the second transistor You may make it improve a defective pixel using at least any one of the wiring parts L13 which connect Q2 and the organic EL element 11. FIG.

Further, the present invention may be embodied in an organic EL display device having a pixel circuit 10 including a driving transistor Qd (conducting type is p-type), two switching transistors Qsw1 and Qsw2, and a current control transistor Qc shown in FIG. Good. In the pixel circuit 10 of FIG. 8, when the selection signal Sy is output for a predetermined period, two of the switching transistors Qsw1 and Qsw are turned on, the current control transistor Qc is diode-connected, and the holding capacitor Cs is opposed to the data signal Dx. Charge is accumulated. Even when the switching transistors Qsw1 and Qsw are turned off, the driving transistor Qd causes the organic EL element 11 to emit light by passing a driving current Id that is relative to the amount of charge accumulated in the holding capacitor Cs.

Also in the pixel circuit 10 configured as described above, at least one of the wiring portion L21 that connects the source of the driving transistor Qd and the power supply line Lv and the wiring portion L22 that connects the driving transistor Qd and the organic EL element 11 is used. Thus, defective pixels may be improved.
In the above embodiment, the light emitting device is embodied in the organic EL display device 1, but is not limited thereto, and may be, for example, a liquid crystal panel or the like, or includes a planar electron-emitting device. It may be a field effect display device (FED, SED, etc.) using light emission of a fluorescent material by electrons emitted from the element.

1 is a schematic plan view showing an organic EL display device embodying the present invention. FIG. 6 is an electric circuit diagram for explaining a pixel circuit. FIG. 3 is a schematic plan view for explaining a layout of a pixel. The principal part longitudinal cross-sectional view for demonstrating the structure of a drive transistor and an organic EL element, and its electrical wiring structure. The schematic plan view for demonstrating the layout of the pixel for describing 3rd Embodiment. The schematic plan view for demonstrating the layout of the pixel for describing 4th Embodiment. FIG. 6 is an electric circuit diagram for explaining a pixel circuit according to another example of the present invention. Similarly, the electric circuit diagram for demonstrating the pixel circuit of another example. The schematic plan view for demonstrating the layout of the pixel for describing 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Organic EL display device as a light-emitting device, 2 ... Transparent substrate, 2a ... Element formation surface, 2b ... Back surface, 6 ... Pixel, 11 ... Organic electroluminescence element as a light-emitting device, 21 ... Organic electroluminescence layer (organic EL layer), 21a ... hole transport layer, 21b ... light emitting layer, L3 ... resistance wiring (wiring), Lb ... resistance wiring element, Qd ... driving transistor as a switching element.

Claims (9)

In a method for improving a light-emitting device in which a light-emitting element and a switching element are formed on a substrate, and the switching element is turned on to supply power from a power line to the light-emitting element to emit light from the light-emitting element.
At least one of the wiring formed between the power supply line and the switching element or the wiring formed between the light emitting element and the switching element is used as a resistance wiring, and the process of forming the resistance wiring forms at least a basic type And a second step of further processing the basic mold. A method for improving a light-emitting device. In the improvement method of the light-emitting device of Claim 1,
The method for improving a light-emitting device, wherein the substrate is a transparent substrate, and the resistance value of the resistance wiring formed in the first step is adjusted in the second step. In the improvement method of the light-emitting device of Claim 1 or 2,
The second step is a laser beam irradiation step, and fusing some or all of the resistance wiring by irradiating a laser beam to the resistance wire through the substrate, so as to adjust its resistance value A method for improving a light-emitting device. In the improvement method of the light-emitting device as described in any one of Claims 1-3,
The resistance wiring is formed by connecting a plurality of resistance wiring elements in parallel, and each of the resistance wiring elements is appropriately selected and cut by irradiating a laser beam to adjust the resistance value. How to improve the device. In the improvement method of the light-emitting device as described in any one of Claims 1-4,
The method for improving a light-emitting device, wherein the switching element is a drive transistor. In the improvement method of the light-emitting device as described in any one of Claims 1-5,
The method of improving a light-emitting device, wherein the resistance wiring is a polysilicon film. In the improvement method of the light-emitting device as described in any one of Claims 1-6,
The method for improving a light-emitting device, wherein the light-emitting element is an electroluminescence element or a light-emitting diode. In the improvement method of the light-emitting device of Claim 7,
In the electroluminescence device, a light emitting layer and a hole transport layer formed between an anode and a cathode are made of an organic material, and a resistance wiring is formed between the anode formed on the hole transport layer side and the switching device. The improvement method of the light-emitting device characterized by the above-mentioned. In a light-emitting device having a plurality of pixels in which a light-emitting element and a switching element are formed on a substrate, the switching element is turned on in response to a selection signal, and power is supplied from a power line to the light-emitting element to emit light.
At least one of the wiring formed between the power supply line and the switching element or the wiring formed between the light emitting element and the switching element is used as a resistance wiring for each of the pixels, A light emitting device characterized in that a resistance wiring is adjusted by adjusting a resistance value by fusing part or all of the specific wiring to the resistance wiring for the specific pixel with a laser beam.

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