JP2009086500A - Defect correction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defect correction method capable of reducing a resistance value of a corrected part. <P>SOLUTION: In the defect correction method, a step in which a correction paste 20 is applied in a range including a disconnection defect part 8b of a drain line 8 and a correction layer 20A having both ends overlapping is formed in a normal part of the drain line and the correction layer 20A is baked by the laser beam irradiation, is repeated a plurality of times to laminate a plurality of baked layers 20A on the disconnection defect part 8b. Consequently, a film thickness of the corrected part is increased to reduce the resistance value of the corrected part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a defect correction method, and more particularly, to a defect correction method for correcting a disconnection defect portion of a wiring formed on a substrate. More specifically, the present invention relates to a defect correction method for correcting a disconnection defect portion of a wiring formed on a TFT (Thin Film Transistor) substrate used in a liquid crystal display.

  In recent years, with the increase in size and definition of flat panel displays such as plasma displays, liquid crystal displays, and EL displays, the probability of defects in electrodes and liquid crystal color filters formed on glass substrates has increased. In order to improve the yield, a method for correcting defects has been proposed.

  For example, electrodes are formed on the surface of a glass substrate of a liquid crystal display. When this electrode is disconnected, the conductive correction paste attached to the tip of the application needle is applied to the disconnected portion, and applied multiple times while shifting the application position in the length direction of the electrode to correct the electrode (for example, , See Patent Document 1).

  Also, there is a method in which a film is provided so as to cover the defective part, the defective part and the film are removed almost simultaneously using laser light, ink is applied to the removed part using the film as a mask, and then the film is peeled and removed. Yes (see Patent Documents 2 and 3, for example).

In addition to this, there is a disconnection correction method using laser CVD (Chemical Vapor Deposition) (for example, see Patent Document 4) and a method of applying a correction paste using a microdispenser (for example, patents). References 5 and 6).
JP-A-8-292442 Japanese Patent Laid-Open No. 11-125895 JP 2005-95971 A JP-A-2005-101222 JP 2003-215640 A JP 2006-202828 A

  However, in the method of correcting the electrode, the conductive correction paste is attached to the tip of the application needle, and the correction paste is transferred to the disconnected portion. Therefore, the application diameter is determined by the flat surface size of the tip of the application needle, and is about 10 μm. It was difficult to realize the coating diameter, and it was also difficult to form a thin line using this.

  Further, in the method using the film as a mask, the film and the defective portion are removed almost simultaneously with the laser beam, so that a large laser power is required and the periphery of the defective portion is damaged. Alternatively, since a hole is formed by laser ablation on the upper part of the film adhering (adhered to) the defect portion, it is assumed that dust generated at that time enters the gap between the film and the substrate and contaminates the vicinity of the defect portion.

  Furthermore, if the correction paste is applied to the holes with the film and the substrate attached or closely adhered, the correction paste is sucked into the gap between the film and the substrate by a capillary phenomenon and spreads, and the substrate may be contaminated.

  Further, the correction method using laser CVD requires a means for supplying and discharging a plurality of source gases to the local space including the disconnection portion, and the apparatus configuration becomes complicated.

  Also, in the method of filling the disconnection portion with the correction paste by the micro dispenser method, it is difficult to control the compressed air supplied to the micro dispenser, and a drawing pattern thinner than 10 μm is required like the drain line (data line) of the TFT substrate. In some cases, application is difficult. In addition, since the microdispenser has a structure with a hollow tapered end, the correction paste is easily clogged, and in order to prevent clogging, it is necessary to use a correction paste managed to have a low viscosity.

  Further, when the drain line of the TFT substrate is corrected, the resistance value of the correction part is required to be 100Ω or less, but it is difficult to apply the correction paste thickly with the same width as the drain line having a width of about 5 μm. In addition, since there are burrs and stepped portions (edges) in the disconnection defect portion of the drain line, cracks are likely to occur in the correction portion, and it is difficult to reduce the resistance value of the correction portion.

  Therefore, a main object of the present invention is to provide a defect correction method capable of reducing the resistance value of the correction portion.

  The defect correction method according to the present invention is a defect correction method for correcting a disconnection defect portion of a wiring formed on a substrate, wherein a correction paste is applied to a range including the disconnection defect portion to form a correction layer. The correction layer is formed so that both end portions thereof overlap normal portions of the wiring, and a plurality of correction layers are stacked on a range including the disconnection defect portion by repeating the step a plurality of times. .

  Preferably, the method includes a second step of firing the correction layer by irradiating the correction layer with laser light, and the first and second steps are alternately repeated.

  Preferably, the method further includes a second step of firing the plurality of correction layers by irradiating the plurality of stacked correction layers with laser light.

Preferably, in the first step, after the correction layer is formed, the correction layer is dried.
Preferably, in the first step, the opening portion of the hole formed in the film is opposed to the disconnection defect portion with a gap, and the film is pressed against the substrate within a predetermined range including the hole and the opening is disconnected through the hole. Apply the correction paste to the area including the defective part.

Also preferably, unused holes are used in each first step.
Also preferably, the same hole is used in the first step multiple times.

  Preferably, in the plurality of first steps, the relative positions of the hole and the disconnection defect portion are not changed in a state where the film is separated from the substrate by the restoring force of the film.

  Preferably, in the first step, after applying the correction paste to the disconnection defect portion through the hole while pressing the film against the substrate in a predetermined range including the hole at the tip portion of the application needle to which the correction paste is adhered, The coating needle is retracted upward, and the film is pulled away from the substrate by the restoring force of the film.

  Preferably, in the first step after the second time, the correction paste is not replenished to the tip of the application needle.

  Also preferably, in the first step, the belt-like film is folded and placed up and down, the upper film is irradiated with laser light to form a hole, the film is wound and the hole is positioned on the lower film, and the lower film Is placed above the substrate and a coating needle is placed on the lower film.

  Further, preferably, before disposing the coating needle on the lower film, a part of the upper film is moved to expose the holes formed in the lower film.

  Preferably, the substrate is a TFT substrate.

  In the defect correction method according to the present invention, the step of applying the correction paste to the range including the disconnection defect portion and forming the correction layer in which both ends overlap the normal portion of the wiring is repeated a plurality of times, A plurality of correction layers are stacked. Therefore, it is possible to reduce the resistance value of the correction portion by increasing the thickness of the correction portion.

  FIG. 1A is a plan view showing a main part of a TFT substrate 1 to be corrected, and FIG. 1B is a cross-sectional view taken along the line IB-IB in FIG. 1A and 1B, a TFT substrate 1 includes a glass substrate 2. A gate line 3 extending in the left-right direction in the figure is formed on the surface of the glass substrate 2, and a gate electrode 3 a protruding downward in the figure is formed at a predetermined position of the gate line 3. The surfaces of the gate line 3 and the gate electrode 3 a are covered with a gate insulating film 4, and the surfaces of the gate insulating film 4 and the glass substrate 2 are covered with a gate insulating film 5.

  A plurality of pixel electrodes 6 are formed in a matrix on the surface of the gate insulating film 5. A gate line 3 is arranged in a region between two pixel electrodes 6 adjacent in the vertical direction in the drawing. A semiconductor film 7 is formed above the gate electrode 3a via gate insulating films 4 and 5. A drain line 8 extending in the vertical direction in the figure is formed in a region between two pixel electrodes 6 adjacent in the horizontal direction in the figure, and protrudes leftward in the figure at a predetermined position of the drain line 8. A drain electrode 8a is formed. The end of the drain electrode 8 a extends to the surface of one end of the semiconductor film 7. A source electrode 9 is formed from the surface of the other end of the semiconductor film 7 to the surface of one end of the pixel electrode 6.

  In this way, the TFT 10 including the gate electrode 3a, the drain electrode 8a, the source electrode 9, and the semiconductor film 7 is formed. The whole is covered with a protective film 11 and an alignment film (not shown) to complete the TFT substrate 1. The TFT substrate 1, the liquid crystal and the color filter constitute a liquid crystal panel.

  Here, as shown in FIG. 1A, it is assumed that a disconnection defect portion 8 b exists in the drain line 8. When the disconnection defect portion 8b is corrected after the protective film 11 is formed, a part of the protective film 11 is removed by laser processing to expose the disconnection defect portion 8b, a correction paste is applied, and a cured film formation process is performed. After securing the conduction of the drain line 8, it is necessary to re-form the protective film 11 on the correction portion. Therefore, it is preferable to correct the disconnection defect portion 8b in the step before the formation of the protective film 11 so as to simplify the correction effort. For example, there is no protective film 11 when the formation of the drain line 8 is completed, and the disconnection is corrected at this point.

  FIG. 2 is a diagram showing a defect correction method as the basis of the present invention. In FIG. 2, in this defect correction method, the correction paste 20 is applied so as to overlap the normal drain line 8 including the disconnection defect portion 8b, and the correction layer 20A made of the applied correction paste 20 is formed. Next, the correction layer 20A is irradiated with a laser beam and locally heated, and a metal film is deposited to ensure the conductivity of the correction layer 20A. In many cases, the line width Dw of the drain line 8 is 10 μm or less, and those having a line width of 5 μm or less are manufactured as the definition becomes higher.

  Thus, when the correction paste 20 is applied with substantially the same width without protruding from the thin drain line (pattern) 8 of 5 μm or less, the film thickness Rt of the correction layer 20A is the same as that of the correction paste 20 as shown in FIG. It depends on the contact angle with the drain line 8 and the wettability, and it is difficult to obtain a film thickness Rt of 1 μm or more, and the film thickness Rt remains around 0.5 μm. As the correction paste 20, a paste in which metal nanoparticles are dispersed or a metal complex solution is used. However, since the thickness of the fired layer obtained by firing the correction layer 20A contracts to about 1/10, the drain line Cracks are likely to occur in the fired layer at the step portion (edge) associated with the thickness Dt of 8, which causes the resistance value of the correction portion to increase.

  In order to make the fired layer obtained by firing the correction layer 20A thicker, it is necessary to increase the thickness of the correction layer 20A applied to the defect portion 8b. Embodiments for that purpose will be described below. .

  FIG. 4 is a diagram showing a defect correction method according to an embodiment of the present invention. In FIG. 4, the correction target is the TFT substrate 1 without the protective film 11, and the film 12 having the holes 12a is used as a mask. The film 12 is disposed on the upper surface of the TFT substrate 1 with a certain gap G in a state where the hole 12a is aligned above the disconnection defect portion 8b. The film 12 is, for example, a thin polyimide film, and the width of the film 12 only needs to be sufficient to be used as a mask. For example, the film 12 is a roll-shaped film slit to about 5 mm to 15 mm, and the thickness Ft is The thing of the grade which can see through below is preferable, for example, is about 10-25 micrometers.

  The opening of the hole 12a has, for example, a square shape with a short axis length Sw and a long axis length Sl, so that the correction paste 20 can be applied to the normal drain wires 8 located at both ends of the disconnection defect portion 8b. The long axis length Sl of the hole 12a is set to be longer than the disconnection defect portion 8b. In this way, if the hole 12a is formed so as to overlap the normal drain line 8, a region where the correction layer 20A and the normal drain line 8 overlap can be secured. Improvements can be expected.

  The hole 12a is formed by laser ablation by laser irradiation. As the laser, a pulse laser such as a YAG third harmonic laser, a YAG fourth harmonic laser, or an excimer laser is used. For example, as shown in FIG. 5, the laser unit 13 is fixed to the upper part of the observation optical system 14 and is irradiated with laser light from an objective lens 15 fixed to the lower end of the observation optical system 14. The shape and dimensions of the hole 12a are determined by, for example, a variable slit (not shown) built in the laser unit 13, and are processed into a cross-sectional shape of the laser beam condensed by the objective lens 15.

  The step of opening the hole 12a in the film 12 is performed by the film 12 alone so that the laser beam does not hit the position away from the disconnection defect portion 8b or the disconnection defect portion 8b. For example, the film 12 is held in a state of being horizontally supported by the left and right fixed rollers 16 and 17 at a position away from the TFT substrate 1, and laser light is applied to the film 12 that hits the center of the left and right fixed rollers 16 and 17. To form a hole 12a. At this time, a shielding plate 18 may be disposed between the TFT substrate 1 and the film 12 so that dust generated by laser ablation does not fall on the TFT substrate 1. It is also possible to perform laser ablation on a portion other than the TFT substrate 1 so that foreign matter is not scattered on the TFT substrate 1.

  As described above, since the hole 12a is not processed by laser irradiation in a state where the film 12 is attached or adhered to the disconnection defect portion 8b, the drain line 8 and the vicinity of the disconnection defect portion 8b are not damaged. Moreover, since the hole 12a is opened in a state where the film 12 is floated, it is possible to prevent foreign matter (dust) generated during laser ablation from adhering to the back surface of the film 12.

  At the time when the formation of the hole 12a is completed, the dust generated when the laser ablation of the hole 12a is scattered on the surface of the film 12 around the hole 12a. A step of irradiating a laser beam with a weak power over a wide area around it may be included. At this time, by switching to the YAG second-harmonic laser and irradiating the laser with a weak power over a wide range centered on the hole 12a, it is possible to remove only dust and prevent new dust from being generated. can do. In the apparatus shown in FIG. 5, dust attached to the back surface of the film 12 cannot be removed by laser irradiation. However, if a film reversing mechanism (not shown) is provided, the back surface of the film 12 can be processed in the same manner as the front surface.

  The hole 12a and the disconnection defect portion 8b opened in the film 12 are positioned by relative movement between the TFT substrate 1 and the film 12 based on the image processing result or the respective position coordinate data, and they have a certain gap. It will be in a state of confrontation. This step may be performed manually. FIG. 6 shows a state in which the hole 12a and the disconnection defect portion 8b face each other with a gap G therebetween. The film 12 is in a state of being stretched by a certain tension. The gap G varies depending on the distance between fulcrums (for example, the fixed rollers 16 and 17 shown in FIG. 5) supporting the film 12 and the thickness of the film 12, but is set to about 10 to 1000 μm, for example. Since a plurality of patterns are laminated on the surface of the TFT substrate 1, the surface is uneven. However, if the gap 12 is maintained so that the film 12 in a minute range including the holes 12 a does not contact the TFT substrate 1. good. For example, the gap G is set to about 200 μm.

  Application of the correction paste 20 is performed using an application needle 19 as shown in FIG. The tip of the application needle 19 is pointed, but a flat surface 19a is formed at the tip. The diameter of the flat surface 19a is, for example, about 30 to 100 μm, and an optimum diameter is selected according to the size of the hole 12a. It is preferable to select and use the application needle 19 having a flat surface 19a having a dimension capable of closing the whole hole 12a. If such an application needle 19 is used, the hole 12a can be filled with the correction paste 20 in one application operation.

  If the application needle 19 is lowered from above in the center of the hole 12a in a state where the correction paste 20 is attached around the flat surface 19a of the application needle 19, the film 12 is deformed and a film in a minute range around the hole 12a. 12 adheres to the periphery of the disconnection defect portion 8b, and the correction defect 20 is filled in the disconnection defect portion 8b. The application needle 19 is held by a guide (linear motion bearing) (not shown) so as to be able to advance and retreat in the vertical direction, and pushes the film 12 only by its own weight of the movable part including the application needle 19. Even if the coating needle 19 descends and the film 12 comes into contact with the periphery of the disconnection defect portion 8b and then further descends, the coating needle 19 retreats upward along the guide, so that the flat surface 19a of the coating needle 19 is excessive. There is no load. The application needle 19 is time-controlled by a control means (not shown) and controlled.

  The time during which the film 12 in a minute range including the hole 12a contacts the periphery of the disconnection defect portion 8b is while the coating needle 19 is pressing the film 12, and the correction paste 20 is applied to the film 12 and the TFT substrate 1 (disconnection defect portion 8b). The applicator needle 19 is retracted upward before flowing in the gap with the vicinity) by capillary action. When the application needle 19 is separated from the film 12, the film 12 returns to its original state due to the elasticity of the film 12, and the film 12 in the minute range including the hole 12a is separated from the disconnection defect portion 8b. Therefore, the time for the film 12 to contact the TFT substrate 1 is very short.

  FIG. 8 shows a state in which the application needle 19 is retracted upward, and the film 12 has returned to a state of being separated from the TFT substrate 1, and the disconnection defect portion 8b has a shape that is substantially the same as the shape of the hole 12a. Layer 20A remains. Further, the excessively applied correction paste 20 remains on the surface of the film 12 and in the holes 12a. Thus, since correction is performed using the film 12 as a mask, it is possible to obtain a correction layer 20A (pattern) that is finer than the application shape of the application needle 19.

  If the disconnection defect portion 8b is corrected by such a method, the applied correction paste 20 is not sucked into the gap between the TFT substrate 1 and the film 12 by capillary action, and covers a wider range than the hole 12a. There is no worry of contaminating the TFT substrate 1. Further, since the film 12 is completely separated from the disconnection defect portion 8b and the TFT substrate 1 when the application is finished, the film 12 comes into contact with the correction layer 20A when the film 12 is removed in the subsequent process. Thus, there is no worry of breaking the correction layer 20A.

  If the viscosity of the correction paste 20 is large, the possibility of being sucked into the gap between the TFT substrate 1 and the film 12 by a capillary phenomenon is reduced, but conversely, the fluidity deteriorates and does not enter the entire hole 12a. It is also assumed that the correction paste 20 does not adhere to the part 8b. On the other hand, as described above, since the film 12 in the vicinity of the hole 12a is attached to the periphery of the disconnection defect portion 8b only at the time of application, the influence of the capillary phenomenon can be kept to a minimum. Therefore, the viscosity of the correction paste 20 may be small.

  Even if the film 12 to be used has a film thickness of, for example, 10 μm, it is difficult to obtain the correction layer 20A having the same film thickness as the film 12. For example, since the through hole 12a of the film 12 is processed to be equal to or smaller than the line width of the drain line 8, if the line width of the drain line 8 is 5 μm, the hole 12a is formed with a width smaller than the film thickness of the film 12. It will be. For this reason, even if the correction paste 20 flows into the hole 12a and adheres to the disconnection defect portion 8b, when the hole 12a leaves the TFT substrate 1, most of the correction paste 20 remains in the hole 12a and the correction layer 20A. The film thickness remains at 1 μm or less. This tendency does not change much even if the viscosity of the correction paste 20 is changed.

  The correction layer 20A is subjected to a firing process by local heating. For example, after removing the film 12 from above the disconnection defect portion 8b, a metal deposition process is performed with a continuous wave laser (for example, YAG second continuous wave laser). In this case, the mechanism is simple if the laser unit 13 is of a type that can switch between pulse oscillation and continuous oscillation. However, if switching is not possible, the observation optical system starts from a continuous oscillation laser (not shown) separate from the laser unit 13. It is preferable to be able to irradiate laser light through 14. Or you may provide the optical system for baking in the position distant.

  FIGS. 9A and 9B are diagrams showing a method of firing the correction layer 20A applied to the disconnection defect portion 8b by laser irradiation. As shown in FIG. 9A, the firing laser light is condensed to a spot diameter of, for example, about 10 μm by the objective lens 15, and laser is applied in the extending direction of the drain line 8 from one end to the other end of the correction layer 20A. Firing is performed by scanning light. The thickness of the fired layer 20AA obtained by firing the correction layer 20A shrinks to about 1/10 of the thickness of the correction layer 20A, as shown in FIG. 9B. For example, if the thickness of the correction layer 20A is 0.5 μm, the thickness of the fired layer 20AA is about 0.05 μm, which is much thinner than the thickness Dt of the drain line 8. For this reason, the stepped portion (edge portion) 8c of the drain line 8 is likely to be disconnected, and the resistance value of the correction portion cannot be reduced.

  Therefore, in this embodiment, the steps from coating to firing shown in FIG. 5 to FIG. 9 are performed a plurality of times on one disconnection defect portion 8b, whereby a plurality of fired layers 20AA are formed on the disconnection defect portion 8b. Laminate on top. Therefore, it is possible to reduce the resistance value of the correction portion by increasing the film thickness of the correction portion including the plurality of fired layers 20AA.

  However, in this embodiment, since a plurality of holes 12a formed in the film 12 are used, it takes time to position the holes 12a and the disconnection defect portion 8b, and the time required for correcting the disconnection defect portion 8b. Becomes longer. Therefore, a modified example that can solve this problem will be described.

  FIGS. 10A to 10C are cross-sectional views showing modified examples of this embodiment. In FIG. 10A, as in FIG. 8, the correction paste 20 is applied to the disconnection defect portion 8 b through the hole 12 a of the film 12, the coating needle 19 is retracted upward, and the film 12 is restored by the restoring force of the film 12. Is away from the TFT substrate 1. While this state is maintained, the process waits for a while while the correction layer 20A1 (first correction layer) is dried. The correction layer 20A1 is small and easily dried, and the waiting time varies depending on the type of the correction paste 20 to be used, but is, for example, about several seconds to several tens of seconds. In order to promote drying, the TFT substrate 1 may be heated appropriately, a solvent having a moderately high volatility may be used as the solvent of the correction paste 20, and a photocuring agent (ultraviolet curing) is used as the correction paste 20. Agent) may be added. Further, the correction layer 20A may be dried by blowing air from the local blowing means to the correction layer 20A.

  When the standby is completed, as shown in FIG. 10B, the correction paste 20 is applied over the correction layer 20A1 using the same hole 12a. At this time, since the relative position between the hole 12a and the disconnection defect portion 8b is not changed, the correction paste 20 may be applied as it is around the flat surface 19a at the tip of the application needle 19. Further, since the correction paste 20 is already filled in the hole 12a, the correction paste 20 does not flow into the disconnection defect portion 8b in a large amount by the second application. In addition, at the time of the 2nd application | coating, you may change and apply to the application needle | hook 19 to which the correction paste 20 has not adhered.

  FIG. 10C shows a state where the second application is completed. Since the correction layer 20A2 (second correction layer) formed by the second application is stacked on the correction layer 20A1 formed by the first application, the film thickness of the correction layer 20A becomes thicker. .

  Thereafter, the correction layer 20A is fired by the method shown in FIGS. 9A and 9B, and the conductive fired layer 20AA is obtained. At this time, since the thickness of the correction layer 20A is thick, the generation of cracks in the step portion of the drain line 8 is prevented, and the resistance value of the fired layer 20AA can be reduced.

  In this modified example, since the same through-hole 12a is used as a mask in the first application and the second application, the correction time is greatly shortened as compared with the case of applying by using different through-holes 12a. . Moreover, since the positions of the disconnection defect portion 8b and the through-hole 12a are not shifted even after the first application, the position adjustment is unnecessary.

  If the number of times the correction paste 20 is applied to the same disconnection defect portion 8b using the same hole 12a is increased, the thickness of the correction layer 16A is increased, and the fired layer 16AA in the step portion 8c of the drain line 8 is increased. The generation of cracks can be avoided. Therefore, in order to reduce the resistance of the correction portion, it is preferable to increase the number of times the correction paste 20 is applied. However, as the number of times of application increases, the amount of the correction paste 20 supplied to the disconnection defect portion 8b increases accordingly, and the shape of the correction layer 20A may be destroyed. Decided in a timely manner. Usually, even when the number of coatings is about twice, there is an effect in reducing the resistance.

  Hereinafter, various apparatuses for executing the above-described embodiment and modified examples will be described. FIGS. 11A and 11B are diagrams showing a film supply unit 25 that causes the film 12 to face the TFT substrate 1 with a certain gap. The film 12 coming out from a film supply reel (not shown) is taken up by a film take-up reel (not shown) via fixed rollers 26 to 28. The film 12 is folded left and right and stretched up and down in parallel by the fixed rollers 27 and 28 disposed on the left and right sides and the fixed roller 26 disposed between them. As shown in FIG. 11A, the film 12A between the fixed rollers 26 and 27 is irradiated with laser light to form a hole 12a. At this time, the shielding plate 18 may be disposed between the films 12 stretched up and down in parallel so that dust generated by laser ablation does not fall on the TFT substrate 1.

  The film supply unit 25 is movable in the XYZ directions by an XYZ stage (not shown). The XYZ stage is used for position adjustment between the disconnection defect portion 8b and the hole 12a. Further, the film supply unit 25 may be provided with a rotating means that rotates in parallel with the TFT substrate 1 so that the inclination of the drain wire 8 and the through hole 12a can be finely adjusted.

  In FIG. 11 (a), the film 12 is folded back to the left and right, and when the hole 12a is opened in the upper film 12, the film 12 is also present below it at a slight distance. In the case where the film 12 is used as a substitute for the shielding plate 18, the shielding plate 18 can be omitted.

  At the time when the formation of the holes 12a is completed, dust generated during laser ablation is scattered on the surface of the film 12A. In order to remove dust, a step of irradiating laser light with weak power to a wide range around the hole 12a may be included. At this time, by switching to the YAG second harmonic laser and irradiating a wide range centering on the hole 12a with a weak laser power, it is possible to remove only dust and prevent new dust from being generated. can do. As the laser unit 13, a laser unit that can selectively emit one of two types of laser beams, that is, a laser beam for opening the hole 12a and a laser beam for removing dust is preferably used.

  As described above, since the hole 12a is not processed by the laser beam with the film 12 attached or adhered to the disconnection defect portion 8b, the vicinity of the disconnection defect portion 8b of the TFT substrate 1 is not damaged by the laser beam. . Moreover, since the hole 12a is opened in the state where the film 12 is floated, it is possible to prevent dust from adhering to the back surface of the film 12. If the film 12 is irradiated with laser at a position other than the TFT substrate 1, contamination of the TFT substrate 1 with foreign matter can be prevented.

  Next, as shown in FIG. 11B, the film 12 is wound in the R direction (clockwise direction) in the figure, and the film 12 is inverted so that the surface of the film 12A faces downward. Next, the film 12 is moved relative to the TFT substrate 1 based on the image processing result, and the hole 12a and the disconnection defect portion 8b are aligned so that the TFT substrate 1 and the film 12 face each other. This step may be performed manually. The film 12 is in a state of being stretched by a certain tension. The gap G varies depending on the distance between fulcrums (for example, fixed rollers 27 and 28) that support the film 12, the thickness of the film 12, and the tension applied to the film 12, but is set to about 10 to 1000 μm, for example. Next, a coating unit (not shown) is inserted between the films 12 stretched up and down, and the correction paste 20 is applied from above the holes 12a.

  12A to 12C are cross-sectional views showing the configuration and operation of another film supply unit 35 that disposes the film 12 on the TFT substrate 1. FIGS. 13A and 13B are views of FIGS. 12A and 12B viewed from above. In the defect correcting apparatus including the film supply unit 35, the upper film 12A located above the disconnection defect portion 8b is mechanically moved so that only the lower film 12B is disposed above the disconnection defect portion 8b. Then, the correction paste 20 is applied to the disconnection defect portion 8b through the hole 12a of the lower film 12B.

  That is, in FIG. 12A, a detachable film supply reel and a film take-up reel (not shown) are mounted on the film supply unit 35. The film 12 supplied from the film supply reel is guided between the objective lens 15 and the TFT substrate 1 via the fixed rollers 36 to 38, folded back by the fixed roller 39, and taken up via the fixed roller 40. It is wound on a reel.

  The fixed rollers 37 and 38 are fixed to the movable member 41 and are movable in the vertical direction within a certain range. In FIG. 12A, the movable member 41 is fixed at an upper position. In this state, the upper film 12A in the section L1 supported by and fixed between the fixed rollers 37 and 38 and the lower film 3B in the section L2 sandwiched between the fixed rollers 39 and 40 are spaced at a certain interval, for example, about It is in a state of being stretched substantially in parallel while maintaining around 10 mm, and also faces the TFT substrate 1 in a substantially parallel manner. The section L2 portion (film placement portion 35a) of the film supply unit 35 is inserted below the objective lens 15 and used for correction using the film 12 as a mask.

  A hook 42 for moving the upper film 12A is disposed below the upper film 12A in the section L1. The hook 42 includes a flat plate member having a slightly wider width than the film 12 and two claws 42a erected at a predetermined interval at one end (front side in the figure) of the flat plate member. Is provided so as to be movable in a direction (width direction) perpendicular to the upper film 12A. In FIG. 12A, the hook 42 is not in contact with the upper film 12A, and a certain gap is secured between them.

  As shown in FIG. 13A, the fixed rollers 36, 39, and 40 are fixed to a support base 43, and a linear motion guide member 44 is interposed between the movable member 41 and the support base 43. An arm 46 is fixed to the other end of the pin 45 fixed to the movable member 41, and the arm 46 is fixed to the output shaft of the air cylinder 47. The movable member 41 can be moved up and down by moving the output shaft of the air cylinder 47 up and down. The hook 42 is fixed to the output shaft of the air cylinder 48, and the hook 42 is substantially perpendicular to the feeding direction of the film 12 by moving the output shaft of the air cylinder 48 in a substantially horizontal direction with respect to the TFT substrate 1. It is possible to move in the direction.

  In this state, the through-hole 12a having a shape corresponding to the shape of the disconnection defect portion 8b is formed by irradiating a laser beam on the upper film 12A substantially at the center of the section L1. At this time, the flat plate member of the hook 42 functions as a shielding plate and receives foreign matter (dust) generated by laser ablation, so that the TFT substrate 1 can be prevented from being contaminated. A recess for receiving dust may be formed on the upper surface of the flat plate member of the hook 42. At the time when the formation of the holes 12a is completed, dust generated during laser ablation is scattered on the laser irradiation surface of the film 12. In order to remove dust, a step of irradiating a laser beam with weak power may be put in a wide range around the hole 12a. At this time, by switching to the YAG second harmonic laser and irradiating a wide range centering on the hole 12a with a weak laser power, it is possible to remove only dust and prevent new dust from being generated. can do.

  Next, as shown in FIG. 12B, the hole 12a is moved to the approximate center of the lower film 12B in the section L2 while the film 12 is being taken up by the film take-up reel. Next, when the hook 42 is moved backward, the film take-up reel (not shown) is prevented from returning backward, so that the film 12 is supplied from the film supply reel (not shown) as shown in FIG. Thus, the upper film 12A is pulled by the claw 42a of the hook 42 and moves rearward, and the lower film 12B including the hole 12a is exposed when viewed from above. In order to avoid interference between the output shaft of the air cylinder 48 and the movable member 41, the movable member 41 is provided with a U-shaped notch 41a.

  In FIG. 13B, it is described that the upper film 12A is translated in the shape as it is with respect to the TFT substrate 1 by the hook 42, but the film 12 in the hook 42 is actually folded in two. However, there is no problem in terms of function.

  From this state, as shown in FIG. 12C, the movable member 41 is lowered so that the fixed rollers 37 and 38 fixed to the movable member 41 are positioned below the fixed rollers 39 and 40. . In this way, the lower film 12B faces the TFT substrate 1 between the fixed rollers 37 and 38 substantially in parallel. Since the film 12 is always in a state where a constant tension is applied and the lower film 12B between the fixed rollers 39 and 40 is pushed downward by the fixed rollers 37 and 38, the film 12 may be bent. In addition, the influence of twisting of the film 12 due to the mechanical lateral movement of the upper film 12A does not reach the lower film 12B between the fixed rollers 37 and 38.

  Next, the disconnection defect portion 8b and the hole 12a are aligned so that the lower film 12B including the hole 12a and the TFT substrate 1 face each other with a certain gap G. Thereafter, as shown in FIG. 10B, when the correction paste 20 is applied with the application needle 19, the correction that secures the coating film thickness is completed without contaminating the vicinity of the disconnection defect portion 8b.

  It is also possible to form the holes 12a in the lower film 12B in the state shown in FIG. 13B, that is, in a state where the upper film 12A is laterally moved by the hook 42.

  12 (a) to 12 (c) and FIGS. 13 (a) and 13 (b), the film 12 is folded back by the fixed roller 39, and the upper film 12A and the lower film 12B are arranged vertically at regular intervals. In this state, since the upper film 12A is mechanically moved laterally and correction is performed with one lower film 12B, alignment between the disconnection defect portion 8b and the hole 12a is facilitated.

  Further, since there is no object above the hole 12a of the lower film 12B, it is possible to perform alignment by switching to a high magnification objective lens (for example, 20 times) having a short working distance WD. In addition, since the interference between the coating means and the upper film 12A can be avoided, the distance between the upper film 12A and the lower film 12B can be narrowed, and switching to a high-magnification objective lens is facilitated.

  In the above example, one hole 12a is formed in the film 12 by the laser unit 13 and a fine pattern is drawn using the hole 12a as a mask. However, it is supported by the fixed rollers 26 and 27 (or 37 and 38). When a plurality of holes 12a are formed on the film 12 at intervals, and the holes 12a are sequentially selected and used for correction, the usage amount of the film 12 can be reduced and the tact time for correction can be reduced. Can be shortened. This method is particularly effective in an apparatus in which the film 12 is folded up and down.

  As an example of the application means, there is an application unit 49 shown in FIGS. 14 (a) and 14 (b). The coating unit 49 has a first hole 50a opened at the bottom thereof, a container 50 into which the correction paste 20 has been injected, a second hole 51a opened, a lid 51 that seals the container 50, a first and a first And the application holes 19 having substantially the same diameter as the two holes 50a and 51a. The flat surface 19 a at the tip of the application needle 19 penetrates the second hole 51 a and is immersed in the correction paste 20. Since the diameters of the first and second holes 50a and 51a are slightly larger than the diameter of the application needle 19 penetrating them, the surface tension of the correction paste 20 and the water / oil repellency of the container 50 There is almost no leakage of the correction paste 20 from the first hole 50a.

  A hole formed in the container 50 for injecting the correction paste 20 has a tapered shape in which the cross-sectional area decreases as the hole 50a is approached. Therefore, the tip portion including the flat surface 19a of the application needle 19 can be immersed with a small amount of the correction paste 20, which is economical. The amount of the correction paste 20 is, for example, 20 μl (microliter). Some of the correction pastes 20 do not last for a long time, and the container 50 is periodically replaced. Alternatively, the used container 50 can be reused after washing. In order to simplify the attachment and detachment of the container 50, a structure that can be easily grasped by hand and an attachment and detachment method using suction by a magnet can improve the usability.

  The proximal end portion of the application needle 19 is fixed to the application needle fixing plate 52, and the application needle fixing plate 52 is supported by a guide (linear motion member) (not shown) so as to be movable up and down. In this state, as shown in FIG. 14B, when the flat surface 19a of the application needle 19 is protruded from the first hole 50a provided on the bottom surface of the container 50, the correction paste is applied to the flat surface 19a of the application needle 19. 20 adheres. When the coating needle 19 is further lowered and pressed on the film 12 so as to close the opening of the hole 12a with the flat surface 19a, the film 12 is deformed, and the film 12 in a minute range around the hole 12a is broken. It adheres to the periphery of 8b, and the repairing paste 20 is filled in the disconnection defect portion 8b.

  The application needle fixing plate 52 is supported by a guide (linear motion bearing) (not shown) so as to be able to advance and retreat in the vertical direction, and presses the film 12 only by its own weight of the movable part including the application needle 19. Even if the application needle 19 descends and attempts to further lower the film 12 after contacting the film substrate 12, the application needle 19 retreats upward along the guide, so that the flat surface 19 a of the application needle 19 is overloaded. Don't be. The drive means (not shown) of the application needle 19 is time-controlled and controlled by a control means (not shown).

  In this coating method, since the step of reciprocating the coating needle 19 between the disconnection defect portion 8b and the container (ink tank or paste tank) is omitted, the time required for defect correction is shortened.

  The correction paste 20 is contained in a sealed container 50 except for the holes 50a and 51a, and the application needle 19 is always inserted into the hole 51a of the lid 51 of the container 50 with a small gap. Therefore, the area where the correction paste 20 directly touches the atmosphere is small. Therefore, evaporation of the dilution liquid (solvent) of the correction paste 20 can be prevented, the number of days (exchange period) in which the correction paste 20 can be used can be lengthened, and maintenance of the pattern correction apparatus is reduced. .

  In addition, since the tip including the flat surface 19a of the application needle 19 is immersed in the correction paste 20 in the standby state of the application operation, it is possible to prevent the correction paste 20 attached to the flat surface 19a of the application needle 19 from being dried. In addition, the cleaning process of the application needle flat surface 19a can be omitted.

  Thus, since the application unit 49 can be reduced in size, a plurality of application units 49 having different diameters of the flat surface 19a are prepared, and the application needle 19 is selected and used according to the size of the disconnection defect portion 8b. It is also possible.

  Further, as shown in FIGS. 14A and 14B, the coating unit 49 can be inserted directly under the objective lens 15 and directly above the disconnection defect portion 8b. At this time, in order to secure an insertion space, it is desirable to switch the objective lens 15 to a low magnification. For example, the working distance WD of the 10 × objective lens 15 is about 30 mm, and can be easily inserted if the height of the coating unit 49 is designed to be low.

  In the method described so far, a fine line pattern can be easily formed with a large correction film thickness. For example, a pattern of 10 μm or less can be formed like an electrode correction of a TFT (thin film transistor) panel of a liquid crystal panel. Then, it can be applied to a place where the resistance of the correction portion needs to be lowered. In addition to the electrodes, the black matrix of the liquid crystal color filter has a line width of less than 20 μm due to high definition, and can be applied when the film thickness cannot be ensured by a single application.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a figure which shows the principal part of the TFT substrate which is the correction object of the defect correction method. It is a figure which shows the defect correction method used as the foundation of this invention. It is a figure for demonstrating the problem of the defect correction method shown in FIG. It is a figure which shows the defect correction method by one Embodiment of this invention. It is sectional drawing which shows the process of opening a hole in the film shown in FIG. It is sectional drawing which shows the process of making the hole shown in FIG. 5 confront a disconnection defect part. It is sectional drawing which shows the process of apply | coating correction paste to a disconnection defect part through the hole shown in FIG. It is sectional drawing which shows the state which retracted the application needle | hook shown in FIG. 7 upwards. It is a figure which shows the method of baking the correction layer shown in FIG. It is a figure which shows the example of a change of this embodiment. It is sectional drawing which shows the structure of the film supply unit which makes the film shown in FIG. 4 oppose with a fixed clearance gap with respect to a TFT substrate. It is sectional drawing which shows the structure of another film supply unit. It is a top view of the film supply unit shown in FIG. It is sectional drawing which shows the structure of the application | coating unit using the application needle | hook shown in FIG.

Explanation of symbols

  1 TFT substrate, 2 glass substrate, 3 gate line, 3a gate electrode, 4,5 gate insulating film, 6 pixel electrode, 7 semiconductor film, 8 drain line, 8a drain electrode, 8b disconnection defect, 9 source electrode, 10 TFT , 11 Protective film, 12, 12A, 12B film, 12a hole, 13 laser part, 14 observation optical system, 15 objective lens, 16, 17, 26-28, 36-40 fixed roller, 18 shielding plate, 19 coating needle, 19a flat surface, 20 correction paste, 20A correction layer, 20AA fired layer, 25, 35 film supply unit, 35a film placement part, 41 movable member, 41a U-shaped notch, 42 hook, 42a nail, 43 support base, 44 Linear motion guide member, 45 pins, 46 arms, 47, 48 Air cylinder, 49 Application unit, 50 Container, 50a first hole, 51 lid, 51a second hole, 52 application needle fixing plate.

Claims (13)

In the defect correction method for correcting the disconnection defect part of the wiring formed on the substrate,
Including a first step of forming a correction layer by applying a correction paste in a range including the disconnection defect portion;
The correction layer is formed so that both end portions thereof overlap normal portions of the wiring,
A defect correction method, wherein the first step is repeated a plurality of times to stack a plurality of the correction layers on a range including the disconnection defect portion. A second step of firing the correction layer by irradiating the correction layer with a laser beam;
The defect correction method according to claim 1, wherein the first and second steps are alternately repeated.   The defect correction method according to claim 1, further comprising a second step of firing the plurality of correction layers by irradiating the plurality of stacked correction layers with laser light.   The defect correction method according to claim 1, wherein, in the first step, the correction layer is dried after the correction layer is formed.   In the first step, the opening portion of the hole formed in the film is opposed to the disconnection defect portion with a gap, and the film is pressed against the substrate within a predetermined range including the hole, and the hole is inserted through the hole. The defect correction method according to claim 1, wherein the correction paste is applied to a range including the disconnection defect portion.   6. The defect correcting method according to claim 5, wherein the unused holes are used in each first step.   6. The defect correcting method according to claim 5, wherein the same hole is used in the first step a plurality of times.   8. The plurality of times of the first step, wherein the relative position between the hole and the disconnection defect portion is not changed in a state where the film is separated from the substrate by the restoring force of the film. Defect correcting method described in 1.   In the first step, the film is pressed against the substrate in a predetermined range including the hole at the tip of the application needle to which the correction paste is adhered, and the correction paste is applied to the disconnection defect portion through the hole. 9. The defect correcting method according to claim 5, wherein after the application, the application needle is retracted upward, and the film is pulled away from the substrate by the restoring force of the film.   The defect correction method according to claim 9, wherein in the first step after the second time, the correction paste is not replenished to a tip portion of the application needle.   In the first step, the belt-like film is folded and placed up and down, the upper film is irradiated with laser light to form the hole, the film is wound up and the hole is positioned in the lower film, and The defect correction method according to claim 9, wherein a lower film is disposed above the substrate, and the application needle is disposed on the lower film.   Furthermore, before arrange | positioning the said application needle | hook on the said lower film, a part of the said upper film is moved, and the said hole opened in the said lower film is exposed, It is characterized by the above-mentioned. Defect correction method.   The defect correction method according to claim 1, wherein the substrate is a TFT substrate.

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