JP3150324B2 - Method of inspecting thin film transistor substrate and method of repairing wiring of thin film transistor substrate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a thin film transistor substrate used for a liquid crystal display device and a method for repairing wiring of the thin film transistor substrate. [Prior Art] FIG. 2 shows a case of a 5 × 5 pixel array as an example of an electrical wiring configuration of a thin film transistor active matrix substrate (hereinafter abbreviated as a thin film transistor substrate). The thin film transistor substrate has scanning lines 11 to 15, signal lines 21 to 25, and a thin film transistor 7 and a transparent pixel electrode 8 formed on a glass substrate at each intersection. The basic configuration of the liquid crystal display device is such that the thin film transistor substrate and the common electrode substrate face each other in parallel, and liquid crystal is sealed between the two substrates. 11p〜1
5p and 21p to 25p are electrode terminal pads. In manufacturing a thin film transistor substrate, short-circuit defects 3 between scanning lines and signal lines due to dust and photoresist defects in the manufacturing process are likely to occur. As shown in FIG. 3A, the short-circuit 3 is a short-circuit 3a generated at the intersection of the scanning line and the signal line.
And a short circuit 3b generated in the thin film transistor. These defects cause linear display defects along the scanning lines 13 and the signal lines 23. As a countermeasure, there is a method of providing a plurality of intersections and thin film transistors as shown in FIG. In the case of the figure, the short circuit can be corrected by cutting the wiring at the positions 9a and 9d. However, in order to realize this method, it is necessary to specify the position where the short circuit occurs. FIG. 4 shows an electrical method generally used for short-circuit inspection. In this inspection, in the thin film transistor substrate, the scanning lines 11 to 15 are connected to the external wirings 11d to 15d by the connection wiring 1c, and the signal lines 21 to 25 are also connected to the external wirings 21d to 25d by the connection wiring 2c. Then, a probe or the like is brought into contact with the connection wirings 1c and 2c, a potential difference V is applied between the scanning line and the signal line, and the current value is measured by the ammeter 4 to determine the presence or absence of a short circuit. However, this method has a problem that a pixel address where a short circuit has occurred cannot be specified. In order to solve this problem, the measurement of the current value in a state where a potential difference V is applied only to one scanning line and one signal line was performed for the thin film transistor substrate having the wiring structure shown in FIG. What is necessary is just to perform sequentially for a scanning line and all the signal lines. However, in this method, it is necessary to measure the current value as many times as the product of the number of scanning lines and the number of signal lines, and it takes a long time to measure a thin-film transistor substrate such as a liquid crystal display having a large number of pixels, which is not suitable for practical use. Further, damage to the electrode terminal portions 11p to 15p and 21p to 25p due to the contact of the probe for applying a voltage also becomes a problem.
Further, even if a structure in which a large number of probes are simultaneously contacted in order to shorten the inspection time, it takes a long time to electrically switch the scanning lines or signal lines to be inspected.
Further, in the above-described electrical inspection method, FIG.
As shown in (1), with respect to the intersection of the scanning line and the signal line or a thin film transistor substrate having a plurality of thin film transistors, it is not possible to specify which intersection or the thin film transistor has a short-circuit defect. As a method of shortening the inspection time, combining a thin film transistor substrate and an electrochromic display panel,
Japanese Patent Application Laid-Open No. 1-154092 discloses a method for detecting a defect based on a color development state of a color development film of an electrochromic substrate. According to this method, the color-forming film of the electrochromic display substrate becomes non-color-forming or color-forming depending on the conduction state of each pixel electrode, so that a defective pixel can be specified. However, this method requires a conductive connection through the pixel electrode of the thin film transistor substrate and the color developing film and the electrolytic film of the electrochromic display substrate, so that when a liquid electrolyte is required, there is a problem that the thin film transistor substrate is contaminated. Further, even when a solid is used as the electrolyte, there is a problem that the thin film transistor substrate is easily damaged due to physical contact with the metal wire, and a defect inspection error due to poor connection is liable to occur. [Problems to be Solved by the Invention] As described above, in the related art, it was impossible to detect a short-circuit defect of a thin film transistor substrate in a short time and without damaging the substrate. Further, even if the pixel address where the short-circuit defect exists can be specified, if the intersection of the scanning line and the signal line or the thin film transistor is provided for each pixel, which intersection or the thin film transistor exists in the thin film transistor It was impossible to identify. An object of the present invention is to eliminate short-circuit defects in a thin film transistor substrate.
An object of the present invention is to provide a method of inspecting a thin film transistor substrate and a method of correcting a defect of the thin film transistor substrate in a short time and with minimum contact with the substrate. Another object of the present invention is to provide a method for inspecting a thin film transistor substrate, which can specify which intersection or thin film transistor has a short circuit even at an intersection of a scanning line and a signal line or a thin film transistor substrate having a plurality of thin film transistors. An object of the present invention is to provide a method for repairing a defect of a thin film transistor substrate. Another object of the present invention is to provide a method of inspecting a thin film transistor substrate and a method of correcting a defect of the thin film transistor substrate, which can automatically correct the wiring of the thin film transistor substrate having a short-circuit defect.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a method for inspecting a short-circuit defect of a thin film transistor substrate in which a first wiring layer and a second wiring layer are formed in a matrix.
A voltage is applied to the first wiring layer and the second wiring layer to detect the presence or absence of a short-circuit defect in the thin film transistor substrate. Identify the location of the short-circuit defect in the matrix from the infrared image,
The position in the specified matrix is imaged to obtain a second infrared image of the position in the matrix, and the position where the short-circuit defect has occurred is specified from the second infrared image. In order to achieve the above object, in a method for correcting a short-circuit defect of a thin film transistor substrate in which a first wiring layer and a second wiring layer are formed in a matrix, an image of the first wiring layer is taken. An infrared image of the first wiring layer was obtained, and a second
The infrared image of the second wiring layer is obtained by imaging the wiring layer, and the position where the short-circuit defect of the thin film transistor substrate is caused is identified from the infrared image of the first wiring layer and the infrared image of the second wiring layer. Then, by taking an image of the position where the specified short-circuit defect is occurring, an infrared image of the position where the short-circuit defect is occurring is obtained, and a wiring position to be cut at the position where the short-circuit defect is generated is determined from the infrared image, The wiring is cut by irradiating the determined wiring position to be cut with a laser beam. [Operation] In a normal thin film transistor substrate, the resistance value between the scanning line and the signal line is about several tens of megaohms, so that even when a voltage of about several tens of volts is applied between the scanning line and the signal line, almost no current flows. Absent. On the other hand, when a short-circuit defect between the scanning line and the signal line exists in the thin film transistor substrate, a current flows through the short-circuit defect portion, and the wiring generates heat. By detecting the state of the heat generation by the infrared image detector, a scanning line and a signal line in which a short circuit has occurred can be detected, and an image address in which a short circuit has occurred can be specified. In addition, the short-circuit portion has high infrared light radiation intensity because it has a higher resistance than a normal wiring. Therefore, by detecting the infrared image of the wiring pattern at the short-circuit pixel address, the short-circuit position can be specified from the infrared light intensity distribution. Further, the wiring pattern can be clearly detected by using the visible image. Therefore, a visible image at the same position as the infrared image is detected,
By referring to the position of the wiring pattern in the visible image,
The location of the short circuit can be more easily specified. When the short-circuit position is specified by the above method, the position where the wiring should be cut can be determined. Based on this, the wiring correction irradiation position can be controlled by a laser or the like, and the wiring can be corrected automatically. Further, by reducing the width of the wiring outside the electrode terminal portion of the scanning line and the signal line, the wiring resistance increases, and the amount of heat generated from the wiring increases. This makes it easy to detect the wiring. [Example] Hereinafter, an example of the present invention will be described. FIG. 1 shows a procedure of a method for inspecting a thin film transistor substrate according to the present invention. In the present invention, the inspection is performed in a state where one terminal of each of the scanning line 1 and the signal line 2 of the thin film transistor substrate is electrically connected. First, a continuity test is performed in the same manner as the conventional electrical test method. Next, an address of a pixel in which a short circuit is likely to occur (short-circuit pixel address) is specified for a substrate determined to be defective in the continuity test. Then, the wiring pattern at the address of the short-circuited pixel is sequentially inspected to specify the short-circuit position, and then the wiring is corrected. In the continuity test, a potential difference V is applied between the scanning line 1 and the signal line 2, and a current value is measured by the ammeter 4. In a normal thin film transistor substrate, the resistance between the scanning line 1 and the signal line 2 is about several tens of megaohms, so that almost no current flows even when a voltage of about several tens of volts is applied. On the other hand, when a short-circuit defect 3 exists between the scanning line 1 and the signal line 2, a current flows through the short-circuit portion 3. Therefore, a substrate having a current value equal to or greater than a specified value is determined as a defective substrate in which a short circuit has occurred. In identifying the short-circuit pixel address, the scan line 1
A potential difference V is applied between the scanning line and the signal line 2 to detect heat generation of the wiring due to a current flowing through the scanning line and the signal line in which the short circuit has occurred, and specify the short-circuit pixel address. For this, an infrared microscope 5m that can obtain an output corresponding to the intensity of the infrared light radiated from the heat-generating part in a minute area of about 10 to 30 μm (technique) is used, and the terminals of the scanning line 1 and the signal line 2 are connected Scanning is performed along the broken line 6 to detect a heating wire. FIG. 5 shows a detailed embodiment of the short-circuit pixel address specifying method. In the figure, the thin film transistor substrate
The scanning lines 11 to 15 are electrically connected to the external wirings 11d to 15d formed outside the electrode terminal pads 11p to 15p by the connection wiring 1c, and the signal lines 21 to 25 are formed outside the electrode terminal pads 21p to 25p. The formed external wirings 21d to 25d are electrically connected to the connection wiring 2c. In order to apply a potential difference V between the scanning lines 11 to 15 and the signal lines 21 to 25, a voltage application probe may be brought into contact with the connection wirings 1c and 2c. As shown in the figure, when the short circuit 3 occurs at the pixel where the scanning line 13 and the signal line 23 intersect, the current is supplied from the external wiring 13d → the electrode terminal pad 13p → the short circuit 3
→ The electrode terminal pad 23p → the external wiring 23d flows, and the wiring therebetween generates heat. Therefore, for example, if infrared rays emitted from the external wirings 11d to 15d and the external wirings 21d to 25d are detected by an infrared microscope along the broken line 6, the infrared light intensity distribution waveform of the broken line 6 portion
1t and 2t are obtained. By detecting a position where the intensity of infrared light is strong from these waveforms, the position of the heated wiring, that is, the scanning line 13 and the signal line 23 can be detected. As a result, the short-circuit pixel address can be specified. In this embodiment, when there are N short circuits in the substrate, the number of detected scanning lines and signal lines is N at maximum, and a short circuit may occur at a maximum of N × N intersections. It can be specified as a pixel address. Next, a first embodiment of the short-circuit position specifying method will be described. As shown in FIG. 6, in a substrate having a plurality of intersections of scanning lines and signal lines and a plurality of thin film transistors 7, short-circuit defects may occur in short-circuit candidate regions 73a to 73d. Therefore, in order to correct the wiring, it is necessary to specify (in the short-circuit position specification) in which short-circuit candidate area a short-circuit has occurred. In general,
The short-circuit portion has a high radiation intensity of infrared light because of, for example, a higher resistance than a normal wiring. Accordingly, in this embodiment, as shown in FIG.
It is positioned sequentially within a 5m field of view, and an infrared image is detected. If the intensity of the infrared image is equal to or higher than a predetermined value, it is determined that heat is generated due to the short circuit at the pixel address, and the short circuit position in the infrared image is detected. The short-circuit position may be detected, for example, as a position at which the infrared light intensity becomes maximum. In addition to the short circuit position coordinates in the infrared image obtained in this way, using circuit pattern design data and board positioning coordinate data,
What is necessary is just to determine the short-circuit candidate area where the short-circuit 3 has occurred.
Thereby, it is found that the short circuit 3 shown in FIG. 6 exists in the candidate short circuit area 73c, and the wiring cutting position can be determined to be 9c. If the intensity of the infrared image is less than the predetermined value, it is determined that there is no short circuit at the short-circuit pixel address, and no short-circuit position is specified. Next, a second embodiment of the short-circuit position specifying method will be described with reference to FIG. In the first embodiment, the short-circuit position is specified using only the infrared image. In the present embodiment, the short-circuit position is specified with reference to a visible image that detects the same position as the infrared image. Seventh
FIG. 6B is a visible image obtained by performing the transmission illumination and detecting the wiring pattern shown in FIG. Since the transmitted illumination is illuminated from the back of the substrate, a metal wiring pattern can be detected as a silhouette image as shown in FIG. First, a characteristic pattern as shown in FIG.
At this time, the position 77 of the dictionary pattern 63 is set as the origin, and the short-circuit candidate positions (representative positions of the short-circuit candidate areas) 74a to 74d and the cutting positions
Set the coordinates of 9a to 9d. This allows the dictionary pattern position
If 77 is known, short-circuit candidate positions 74a to 74d and cutting positions 9a to
9d can be determined. In the short-circuit position specification, the wiring patterns at the short-circuit defective pixel addresses are sequentially inspected, but the dictionary pattern position 77 in the visible image changes according to the positioning state of the substrate. Therefore, a visible image is detected by transmitted illumination for each inspection, and the coordinates 77 of the position where the dictionary pattern 63 most matches in the image are obtained by pattern matching. Thereby, the coordinates of the short-circuit candidate positions 74a to 74d and the cutting positions 9a to 9d in the visible image can be calculated. On the other hand, the position of the short circuit 3 is obtained from the infrared image. In this embodiment, since the visible image and the infrared image detect the same position, the coordinates of the visible image and the infrared image are equal. Therefore, among the short-circuit candidate positions 74a to 74d obtained from the visible image, the short-circuit candidate position that minimizes the distance to the position of the short-circuit 3 in the infrared image can be determined as the position where the short-circuit occurs. Thus, similarly to the first embodiment, the short circuit 3 shown in FIG.
It can be seen that it exists in the short-circuit candidate area 73c, and the wiring cutting position can be determined to be 9c. In this embodiment, the coordinate data to be stored in advance is only the short-circuit candidate positions 74a to 74d and the cutting positions 9a to 9d when the position 77 of the dictionary pattern 63 is the origin, and the short-circuit position can be more easily specified. it can. The wiring cutting position is determined by the short-circuit position specifying method described above. Therefore, in the wiring correction, the substrate in which the short circuit has occurred is corrected by cutting the wiring cutting position by a wiring correction method such as the laser 43. Next, a first embodiment of a thin film transistor substrate inspection apparatus will be described with reference to FIGS. This device comprises a mechanical system, a continuity inspection system, and an optical system. The mechanism system includes a θ stage 31, a Z stage 32, a Y stage 33, and an X stage 34, on which the thin film transistor substrate 30 is mounted and an arbitrary position of the substrate 30 is positioned in the optical system field of view. The continuity inspection system includes a DC power supply 35, an ammeter 4, and probes 36a and 36b. The probes 36a and 36b are brought into contact with a wiring pattern to give a potential difference between a scanning line and a signal line.
The presence or absence of a short-circuit defect is determined from the current value. The optical system includes an infrared image detection system, a laser beam irradiation system for cutting wires, a bright field illumination system, a transmission illumination system, and a visible image detection system. The infrared image detection system includes an objective lens 37, a dichroic mirror 38, a lens 39, and an infrared image detector 5, and emits infrared light (wavelength range λ ₁ : about 5
1313 μm). This infrared image detection system is an objective lens
Since the infrared image is enlarged at 37, the intensity of infrared light radiated from a minute area of about 10 to 30 μm (technique) can be detected.
The laser beam irradiation system includes a laser 43, a beam expander 42,
An opening 41 having a moving mechanism (not shown) and a dichroic mirror 40. The laser light transmitted through the opening 41 is reduced by the objective lens 37 and projected onto the thin film transistor substrate 30 to cut the wiring. Lamp 4 for bright-field illumination
6, lens 45, half mirror 44, objective lens 37
The thin film transistor substrate 30 is illuminated from above via the.
The transmission illumination system includes a lamp 50 and a lens 49, and illuminates from the back side of the thin film transistor substrate 30. The visible image detection system includes a visible image detector 48 and a lens 47. The visible image detector 48 is adjusted to detect a visible image at the same position as the infrared image detector 5. In this embodiment, the objective lens 37 needs to transmit light from the visible region to the infrared region, and ZnS or the like may be used as the glass material. The dichroic mirror 38, the light detection wavelength region lambda ₁ of the infrared image detector 5 is reflected and light of a short wavelength from the detection wavelength region lambda ₁ is the optical element of the property of transmitting. Also dichroic mirror 40
Has a characteristic of reflecting the wavelength λ ₂ (λ ₂ <λ ₁ ) of the laser 43 and transmitting visible light (wavelength range λ ₃ : λ ₃ <λ ₂ ).
In this embodiment, the above-described continuity inspection, short-circuit pixel address specification, short-circuit position specification, and wiring correction are realized by one inspection apparatus. Next, an embodiment of an infrared light intensity distribution waveform detection method for specifying a short-circuit pixel address will be described with reference to FIG. The thin film transistor substrate 30 is mounted on an X stage 34 driven by a motor 51 and a feed screw 52. The position of the X stage 34 is detected by the position detector 53, and the infrared light emitted from the substrate 30 is detected by the infrared image detector 5 via the objective lens 37. In the above configuration, at the time of image detection, the output signal of the infrared image detector 5 is sampled and held by the sample and hold circuit 55 based on the signal of the position detector 53, and the A / D converter 56 performs A / D conversion.
The data is converted and stored in the memory 57. By similarly detecting the Y direction, the infrared light intensity distribution waveforms 1t and 2t shown in FIG. 5 are obtained. Next, FIG. 10 shows an embodiment of a circuit configuration for automatically performing short-circuit pixel identification and wiring correction. The image detected by the visible image detector 48 is stored in the image memory 60. Then, after binarization by the binarization circuit 61, pattern matching with the dictionary pattern 63 is performed by the pattern matching circuit 62, and the dictionary pattern position 77 in the detected image shown in FIG. 7 is obtained. The position data and the preset short-circuit candidate position and wiring cut position coordinate data 65 are input to the short-circuit candidate position calculation circuit 64 to calculate the short-circuit candidate position and the wiring cut position. On the other hand, after the image detected by the infrared image detector 5 is stored in the memory 66, first, the presence or absence of heat generation is determined by the heat generation determination circuit 67. That is, if the intensity of the infrared image is less than the predetermined value, it is determined that the pixel address has no short circuit, and the short circuit position is not specified. If the intensity of the infrared image is higher than a certain value, it is determined that there is a short circuit,
The heat generation position detection circuit 68 detects the position where the infrared light intensity is maximum in the image as the heat generation position. The short-circuit position determination circuit 69 determines a short-circuit candidate position closest to the heat generation position obtained by the heat generation position detection circuit 68 as a true short-circuit position. Thereby, the wiring cutting position is also determined. Based on this, the position of the opening 41 of the laser irradiation system is calculated by the opening position calculation circuit 70. Further, the opening controller 71 drives the opening moving mechanism 72 so that the opening
Position 41. Thereafter, via the beam expander 42,
By irradiating the laser, automatically cut the wiring,
Can correct short circuit. Although the above embodiment has described the case where the visible image is referred to for specifying the short-circuit position, when only the infrared image is used, instead of the output of the short-circuit candidate position calculation circuit 64, circuit pattern design data and What is necessary is just to input the short-circuit candidate position obtained from the positioning coordinate data of the substrate to the short-circuit position determination circuit 69. In the above description, the visible image obtained by the transmission illumination is used for detecting the position of the wiring pattern. However, the visible image obtained by the bright field illumination may be used. However, if a binary image of the wiring pattern cannot be obtained stably, it will be necessary to perform pattern matching using a grayscale image. Further, a specific wiring position may be obtained using a method other than pattern matching, for example, a method such as projection. FIG. 11 shows a second embodiment of the thin film transistor substrate inspection apparatus. In this embodiment, the objective lens 83 for visible light and laser light and the objective lens 82 for infrared light are provided independently. For example, objective lenses for visible light and laser light
83 is disposed at the center, and a doughnut-shaped objective lens 82 for infrared light is installed coaxially with the objective lens 83.
The same function as that of the embodiment can be obtained. Reference numeral 84 denotes a mirror having a hole in the center, and an optical element that passes visible light and laser light through the center and reflects only infrared light. In the embodiment of the thin film transistor substrate inspection apparatus described above, the case where the inspection of the short-circuit defect and the correction of the wiring are performed by one apparatus has been described. However, it goes without saying that the short-circuit defect inspection and the wiring correction according to the present invention may be individually performed by separate devices. Next, FIG. 12 shows a first embodiment of an external wiring pattern suitable for specifying a short-circuit pixel address. The heat value of the wiring is W, the wiring resistance is R, the current value flowing through the wiring is I, the volume resistivity of the wiring material is ρ [Ω · m], the wiring length is l, the wiring width is x, and the wiring thickness is t. Then, W = I ² R... R = ρ · l / (x · t)... In other words, by reducing the wiring width or wiring thickness, the amount of heat generated from the wiring per unit length increases,
That is, the intensity of the infrared light emitted from the wiring increases, and the detection of the heated wiring is facilitated. In the embodiment shown in FIG. 12, the wiring widths of the external wirings 23d and 24d are reduced to a width equivalent to the minimum exposure line width of the wiring pattern of the thin film transistor substrate. Since the external wiring is outside the electrode terminal pads 23p and 24p to which the IC for driving the pixel is connected, the external wiring does not affect the operation characteristics of the pixel. Also for driving like electrode terminal pad
There is no need to secure a certain width to reduce the contact resistance with the IC. Therefore, it is feasible to form an external wiring pattern having the above-described shape on the thin film transistor substrate. FIG. 13 shows a second embodiment of the external wiring pattern. The difference from the embodiment of FIG. 7 is that an insulating film 80 such as SiN used in a thin film transistor substrate manufacturing process is coated on the external wiring patterns 23d and 24d and the glass substrate 81. Although the intensity of the infrared light emitted from the object differs depending on the material and the surface condition even at the same temperature of the object, according to the present embodiment, the insulating film 80
The intensity of the infrared light radiated from the surface is detected, the infrared light intensity distribution substantially corresponds to the temperature distribution, and the processing for detecting the position of the heated wiring can be simplified. [Effects of the Invention] As described above, according to the present invention, a short-circuit failure of the wiring of the thin film transistor substrate can be quickly detected, so that a defect inspection of the thin film transistor substrate can be performed in a very short time. Further, the number of times of contact with the probe for defect inspection is extremely small, and it is possible to reduce substrate damage accidents in the inspection process. Further, according to the present invention, it is possible to specify a short-circuit position, which has been impossible in the related art, even on a substrate in which a plurality of thin film transistors or a plurality of intersections of scanning lines and signal lines are formed for each pixel of a liquid crystal display. This makes it possible to correct a substrate having a short-circuit defect. As described above, according to the present invention, the inspection of the thin film transistor substrate can be performed in a very short time, which is effective in improving the yield of the thin film transistor substrate and has a remarkable effect in reducing the cost of the product.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of an embodiment of a method for inspecting a thin film transistor substrate according to the present invention, FIG. 2 is a view showing an example of an electrical wiring configuration of the thin film transistor substrate, and FIG. And FIG. 4 is a diagram showing an example of a wiring structure for preventing short circuit defects.
FIG. 5 is an explanatory view of a conventional electrical short-circuit defect inspection method, FIG. 5 is an explanatory view of a short-circuit pixel address specifying method, FIG. 6 is an explanatory view of a short-circuit position specifying method, and FIG. FIG. 8 is a diagram illustrating a first embodiment of a thin film transistor substrate inspection apparatus, FIG. 9 is a diagram illustrating an image detection method for specifying a short-circuit pixel address, and FIG. 10 is a circuit configuration. FIG. 11 is a diagram showing a second embodiment of the thin film transistor substrate inspection device, and FIGS. 12 and 13 are diagrams showing an embodiment of an external wiring pattern suitable for identifying a short-circuit pixel address, respectively. is there. 1,11-15 scanning line 2,21-25 signal line 3,3a-3d short-circuit defect, 4 ammeter 5 infrared image detector, 5m infrared microscope 6 ... Infrared light intensity detection position, 7,7c-7d ... Thin film transistor 8 ... Transparent pixel electrode, 9a-9d ... Wiring cutting position 11p-15p ... Scanning electrode terminal pad 21p-25p ... Signal electrode terminal Pad 1c, 2c Connection wiring 11d to 15d, 21d to 25d External wiring 1t, 2t Infrared light intensity distribution waveform 30 Thin film transistor substrate 31, 31 θ stage 32 Z stage 32 Y stage 34 X stage 35 DC power supply 36a, 36b Probe 37 Objective lens 38, 40 Dichroic mirror 39, 45, 47, 49 Lens 41 Opening 42 …… Beam expander, 43… Laser 44 …… Half mirror, 46 and 50 …… Lamp 48 …… Visible image detector, 51 …… Motor 52 …… Feed screw, 53 …… Position detector 55… … Sample hold circuit 56… A / D converter, 57… Memory 63… Dictionary patterns 73a to 73d… Short circuit candidate area 74a to 74d… Short circuit candidate position 75 …… Infrared light intensity line 76 …… Infrared light intensity distribution waveform 77 ... Dictionary pattern position, 80 ... Insulating film 81 ... Glass substrate 82 ... Objective lens for infrared light 83 ... Objective lens for visible light and laser light 84 ... Center Mirror with a hole in the part

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI G09G 3/36 H01L 21/66 J H01L 21/66 G02F 1/136 500 (72) Inventor Yoshifumi Yoritomi Totsuka-ku, Yokohama-shi, Kanagawa 292 Yoshida-cho, Hitachi, Ltd. Production Engineering Laboratory Co., Ltd. (56) References JP-A-2-64594 (JP, A) JP-A-1-185454 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) G01R 31/02 G02F 1/133 550 G02F 1/1368 G09F 9/00 352 G09G 3/36 H01L 21/66

Claims (4)

(57) [Claims] 1. A method of inspecting a thin film transistor substrate having a first wiring layer and a second wiring layer formed in a matrix for a short-circuit defect, wherein the first wiring layer and the second wiring layer are To detect the presence or absence of a short-circuit defect in the thin-film transistor substrate. If there is the short-circuit defect, the short-circuit defect is detected from a first infrared image of the first wiring layer and the second wiring layer. The position in the matrix is specified, and the position in the specified matrix is imaged to obtain a second infrared image of the position in the matrix.
A method for inspecting a thin film transistor substrate, wherein a position where the short-circuit defect is caused is specified from an infrared image of the substrate. 2. The method according to claim 1, wherein the first infrared image and the second infrared image are obtained by imaging while applying a voltage to the first wiring layer and the second wiring layer. The method for inspecting a thin film transistor substrate according to claim 1. 3. A method for correcting a short-circuit defect of a thin film transistor substrate in which a first wiring layer and a second wiring layer are formed in a matrix, wherein the first wiring layer is imaged and the first wiring layer is imaged.
And an infrared image of the second wiring layer is obtained by imaging the second wiring layer, and an infrared image of the first wiring layer and an infrared image of the second wiring layer are obtained. From the above, the position where the short-circuit defect is caused is specified, and the position where the specified short-circuit defect is caused is imaged to obtain an infrared image of the position where the short-circuit defect is generated, and the infrared image is obtained from the infrared image. A wiring repair method for a thin film transistor substrate, comprising: determining a wiring position to be cut at a position where a short-circuit defect has occurred; and irradiating the determined wiring position to be cut with a laser beam to cut the wiring. 4. An infrared image of said first wiring layer and said infrared image of said second wiring layer.
4. The method for repairing wiring of a thin film transistor substrate according to claim 3, wherein an infrared image of said wiring layer is obtained by imaging while applying a voltage to said first wiring layer and said second wiring layer. .