JP2010145875A - Liquid crystal display device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repair method which repairs display defects due to black spot defects, bright spot defects, disconnection of wiring, or the like of a liquid crystal display device without adding an extra step, and prevents the reduction in an aperture ratio and the loss of long-time reliability due to repair. <P>SOLUTION: A repair electrode conductive to a scanning line or a signal line is preformed on the scanning line or the signal line. When a defect is found, a conductive connection pattern is formed from this repair electrode to a pixel electrode or another repair electrode to repair the display defect. The repair electrode can be formed in a TFT manufacturing step and can be formed under a black matrix together with the connection pattern. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device and a manufacturing method thereof, and more particularly, to a repair technique for a pixel portion and a wiring of a liquid crystal display device.

  In recent years, an active matrix type liquid crystal display device has been widely used as one of display devices, and has been widely used as a display device for television receivers, monitors for personal computers, portable terminals, and the like. In addition, active research and development continues to increase the screen size, resolution, and display quality of liquid crystal display devices. On the other hand, in order to improve the manufacturing yield of liquid crystal display devices and reduce costs, the importance of technology that repairs these defects along with manufacturing technology that reduces the occurrence of point defects and line defects in the manufacturing process of liquid crystal display panels Has increased.

JP-A-9-127549 JP 2002-182246 A

  In an active matrix liquid crystal display device, switching elements are arranged in a matrix in the vicinity of intersections of a plurality of scanning lines and a plurality of signal lines, and pixel electrodes connected to the respective switching elements are formed. Has been. In the liquid crystal display device having such a configuration, particularly in the case of a large-screen liquid crystal display device, display defects such as pixel bright spot defects, dark spot defects, and wiring disconnection defects may occur in the manufacturing process. .

  For example, when a thin film transistor (hereinafter referred to as TFT) used as a switching element is formed poorly, the source region or the source electrode penetrates the gate insulating film and is short-circuited with the scan line. Such defects occur that the potential becomes the same as the potential, or the pixel electrode is short-circuited with the capacitor line formed through the insulating layer, and the potential of the pixel electrode and the capacitor line becomes the same. A pixel having a defect is a pixel having a so-called dark spot defect that causes dark display or a bright spot defect that causes bright display when displayed as a display device. In the case of a dark spot defect, such a defect is likely to be visually recognized when the surrounding pixels are brightly displayed, and in the case of a bright spot defect, such a defect is easily visible when the surrounding pixels are darkly displayed. Further, even when the leak does not occur until such a short circuit occurs, a normal image signal is not supplied to the pixel electrode, and the display gradation of the pixel becomes abnormal regardless of the image signal. In addition, when a disconnection occurs in a signal line or a scanning line, pixels provided after the disconnection portion as a so-called line defect can be luminescent spots, dark spots, or gradation abnormalities in a linear form. Whether it becomes a bright spot defect or a dark spot defect depends on the defect mode, the setting of the transmission axis of the polarizing plate, and the like.

  Therefore, various repair methods have been proposed to deal with these defects. For example, for point defects such as bright spot defects and dark spot defects, a pad extending from the pixel electrode is provided so as to overlap with the signal line, and the signal line and the pixel are irradiated by irradiating the pad with a laser. There is a method in which an image signal from a signal line is supplied to a pixel electrode by connecting the electrode to make the defect inconspicuous (Patent Document 1). However, in this method, the pixel electrode and the signal line are welded so that the signal line is not blown while the insulating layer between the pad extending from the pixel electrode and the signal line is destroyed by the laser. The underlying signal lines are easily damaged and remain problematic in terms of long-term reliability.

  In addition, a method of repairing by a similar method by providing a pad extending from the signal line so as to overlap with the pixel electrode has been proposed, but this method not only has a problem in long-term reliability, but also The signal lines are generally made of metal, and therefore the pads also have light-shielding properties. Therefore, the aperture ratio of all the pixel portions is reduced by the amount of light shielded by the pads regardless of whether the pixel portions are defective or repaired. Will be lowered, which is not preferable. In addition, for line defects such as disconnection of scanning lines, etc., after detecting the disconnection in the inspection process, contact holes are opened on both ends of the disconnection of the wiring, and these contact holes and disconnection portions are formed by laser CVD. There is a method of repairing the disconnection by forming a conductive film that covers (Patent Document 2). However, in this method, after the disconnection is discovered, the substrate is returned to the photolithography process again in order to form such a contact hole. Therefore, the number of PEPs (Photo Engraving Process) and the number of processes increase, and the productivity increases. In addition to a significant decrease, the opening of such contact holes causes a new yield reduction, and there are many problems.

  The present invention has been made in view of the above points, and in the case of repairing display defects, the present invention does not damage signal lines, scanning lines, and insulating layers, and does not reduce the aperture ratio. It is an object of the present invention to provide a liquid crystal display device that enables easy repair. Another object of the present invention is to provide a liquid crystal display device that can be repaired without adding an extra photolithography process. It is another object of the present invention to provide a liquid crystal display device with high display quality and reliability even when such a liquid crystal display device is repaired.

  A liquid crystal display device according to the present invention includes a thin film transistor formed near a signal line and a scanning line and connected to the scanning line and the signal line, and an opening reaching the scanning line or the signal line. An insulating layer formed on the scanning line or the signal line, a pixel electrode made of a transparent conductive layer formed on the insulating layer, connected to the thin film transistor, and the transparent conductive layer so as to cover the opening And a connection pattern that is connected to the repair electrode and repairs a display defect.

  By adopting such a configuration, the present invention enables the repair electrode to be already scanned even when a display defect such as a dark spot defect, a bright spot defect, or a disconnection of a scanning line or a signal line is found. Since one end of the connection pattern is formed on the repair electrode and the other end is formed on the wiring of the pixel electrode or signal line of the pixel portion to be repaired. By connecting on another repair electrode, these display defects can be repaired.

  According to the present invention, the repair electrode is patterned from the transparent conductive layer in the same layer and the same process as the pixel electrode in the normal TFT and pixel electrode forming process, and is formed in advance together with the opening on the scanning line or the signal line. Therefore, even if these display defects are found after the formation of the pixel electrode, a cell array substrate having display defects is formed in order to form a contact hole for repair as in the prior art. An extra step of returning to the photolithography step again becomes unnecessary. Therefore, the number of photolithography processes is not increased and the productivity is improved. In addition, since the contact hole is not newly opened in the cell array substrate after the manufacturing process is almost completed as in the prior art, the yield reduction due to the contact hole opening cannot occur.

  In the present invention, a repair electrode that is electrically connected to a scanning line or a signal line is formed in advance on the scanning line or the signal line, and is made of ITO (Indium Tin Oxide) or the like at the time of repair as in the conventional example. It does not destroy the insulating film between a part of the pixel electrode and the signal line and weld the pixel electrode and the signal line by laser. Therefore, the long-term reliability can be improved without damaging the metal layer such as the lower signal line by the laser beam.

  Further, in the present invention, since the repair electrode is formed on the scanning line or the signal line, the repair electrode is usually formed under the black matrix. Therefore, the aperture ratio is not lowered by providing the repair electrode. Even when the repair is performed using the connection pattern, the connection pattern is only formed in the vicinity of the repair electrode, so that the connection pattern can also be formed under the black matrix. Therefore, the aperture ratio is not reduced by the connection pattern. Even if the connection pattern is formed so as to extend to the outside of the black matrix, in the present invention, the connection pattern is not formed in advance so as to overlap the pixel electrode in all the pixel portions as in the conventional example. Since it is only necessary to form the pixel portion having a display defect such as a defect or a bright spot defect, a decrease in the aperture ratio can be minimized.

  Further, since the repair electrode covers the opening with the transparent conductive layer after opening the insulating layer on the scanning line or the signal line, the scanning line or the signal line which is a metal layer is not exposed in the opening. Therefore, also in this respect, the long-term reliability of the liquid crystal display device can be improved. The liquid crystal display device according to the present invention is characterized in that the repair electrode is provided in the vicinity of the pixel electrode. By adopting such a configuration, the length of the connection pattern can be shortened when repairing a pixel part having a dark spot defect or a bright spot defect by connecting a pixel electrode and a signal line. It is possible to minimize adverse effects such as image signal attenuation due to the resistance of the pattern. In addition, in the case where a disconnection defect occurs in the scanning line or signal line in the vicinity of the pixel electrode in addition to the dark spot defect or the bright spot defect, the repair electrode in the vicinity of the pixel electrode can be used for repairing all of these defects. it can.

  The liquid crystal display device according to the present invention includes a capacitor line that forms a storage capacitor with the pixel electrode, and the repair electrode is on the signal line and is at an intersection of the signal line and the capacitor line. It is formed on both sides. With this configuration, when a short circuit or leak occurs between the capacitor line and the pixel electrode, the short circuit or leak portion between the capacitor line and the pixel electrode is separated from the pixel electrode, and there is no short circuit or leak. By forming a connection pattern between the other pixel electrode and the repair electrode, an image signal from the signal line can be supplied to the pixel electrode free from short circuit or leakage. Since the repair electrode is formed on both sides of the intersection of the signal line and the capacitance line, the pixel electrode which is not short-circuited or leaked on both sides of the capacitance line is connected to the nearest repair electrode. be able to. Therefore, by repairing such defective pixel electrodes, the area of the pixel electrode that does not contribute to normal display can be minimized, and repair can be performed with the shortest connection pattern. In addition, when the signal line is disconnected between the repair electrodes formed on both sides of the intersection of the signal line and the capacitor line on the signal line, the repair electrodes are connected by a connection pattern. Disconnection can also be repaired.

  The liquid crystal display device according to the present invention is characterized in that the connection pattern is connected to a repair electrode formed on the signal line and a pixel electrode of a pixel portion having a display defect. By adopting such a configuration, the image signal supplied from the signal line is supplied to the pixel electrode having the display defect through the connection pattern. A normal image comes to be visually recognized. Therefore, it can be sufficiently used as a liquid crystal display device.

  In the liquid crystal display device according to the present invention, the thin film transistor is formed on the scanning line, and the repair electrode is provided on the scanning line between the thin film transistor and the signal line. And In the liquid crystal display device according to the present invention, the thin film transistor is formed on the scanning line, and the repair electrode is formed on the scanning line between the thin film transistor and an adjacent signal line adjacent to the signal line. It is provided in. By adopting such a configuration, when the scanning line is disconnected, the repair electrodes sandwiching the disconnected portion can be connected with the shortest connection pattern.

  The liquid crystal display device according to the present invention is characterized in that the connection pattern connects the repair electrodes on both sides of the disconnection portion of the signal line or the scanning line. By adopting such a configuration, even in the liquid crystal surface device in which the scanning lines are disconnected, the scanning lines on both sides of the disconnected part are repaired so as to be electrically connected by the connection pattern. A scanning signal supplied from the scanning line is supplied to the gate electrode. Accordingly, the line defect is repaired, and a normal image is visually recognized, thereby improving the manufacturing yield of the liquid crystal display device. The same applies to the signal lines.

  The liquid crystal display device according to the present invention is characterized in that the connection pattern is formed under a black matrix. By adopting such a configuration, not only the repair electrode but also the connection pattern does not protrude outside the black matrix formation region, so that the aperture ratio is not reduced by the connection pattern. Therefore, even a repaired liquid crystal display device can display a bright image with high display quality. In the liquid crystal display device according to the present invention, the transparent conductive layer is made of a conductive material containing ITO, and the connection pattern is made of a metal containing W or Mo. With this configuration, the repair electrode can be formed using the same material and the same process as the pixel electrode, and no special process is required. Further, the laser CVD method can be used by using a metal containing W or Mo as the material of the connection pattern. In addition, when Mo is used, good electrical connection can be achieved without causing electrolytic corrosion between the connection pattern and the ITO of the repair electrode.

  A method of manufacturing a liquid crystal display device according to the present invention includes a first step of forming on a substrate a gate electrode and a scanning line that are formed of a first metal layer and are connected to a thin film transistor, and a first insulating layer is formed on the gate electrode. And a second step of forming a semiconductor layer of the thin film transistor, a source electrode and a drain electrode made of a second metal layer are formed on the semiconductor layer, and connected to the drain electrode on the first insulating layer A third step of forming a signal line to be performed, a fourth step of forming a second insulating layer on the second metal layer, and the first insulating layer and the second insulating layer formed on the scanning line A fifth step of forming an opening penetrating the scanning line and reaching the scanning line or an opening penetrating the second insulating layer formed on the signal line and reaching the signal line; and A pixel electrode made of a transparent conductive layer connected to the source electrode Rutotomoni, characterized in that it comprises a sixth step of forming a repair electrodes made of transparent conductive layer covering the opening. By adopting such a configuration, in a liquid crystal display device including a bottom gate type thin film transistor, in a normal process of manufacturing the thin film transistor and the pixel electrode, on the scanning line made of the first metal layer or the second metal layer. A repair electrode can be formed on the signal line consisting of

  According to the present invention, as described above, even when a display defect is found after the formation of the pixel electrode, an extra process such as returning the cell array substrate to the photolithography process again is unnecessary. Become. Therefore, the number of photolithography processes is not increased and the productivity is improved. In addition, since the contact hole is not newly opened in the cell array substrate after the manufacturing process is almost completed as in the prior art, the yield reduction due to the contact hole opening cannot occur. Further, in the present invention, since the repair electrode that is electrically connected to the scanning line or the signal line is formed on the scanning line or the signal line in advance, the metal layer such as the lower signal line is damaged as in the prior art. It can improve long-term reliability.

  Furthermore, in this invention, an aperture ratio does not fall by providing a repair electrode. Further, since the repair electrode is covered with the transparent conductive layer after the insulating layer on the scanning line or the signal line is opened, the scanning line or the signal line which is a metal layer is not exposed in the opening. Therefore, also in this respect, the long-term reliability of the liquid crystal display device can be improved.

  A method of manufacturing a liquid crystal display device according to the present invention includes a first step of forming on a substrate a source electrode made of a first metal layer, connected to a thin film transistor, a drain electrode, and a signal line connected to the drain electrode, A second step of forming a semiconductor layer of the thin film transistor on the source electrode and the drain electrode, and a scan made of the second metal layer through the first metal layer and the first insulating layer formed on the semiconductor layer. A third step of forming a line and a gate electrode; a fourth step of forming a second insulating layer on the second metal layer; and the first and second insulating layers formed on the signal line. A fifth step of forming an opening penetrating the insulating layer and reaching the signal line or an opening penetrating the second insulating layer formed on the scanning line and reaching the scanning line; and the second insulating layer A pixel electrode comprising a transparent conductive layer connected to the source electrode To form a, characterized in that it comprises a sixth step of forming a repair electrodes made of transparent conductive layer covering the opening. By adopting such a configuration, even in a liquid crystal display device including a top-gate thin film transistor, the repair electrode as described above can be formed in a normal process for manufacturing the thin film transistor and the pixel electrode. Therefore, the same effect as described above can be obtained.

  In the method for manufacturing a liquid crystal display device according to the present invention, after the pixel electrode and the repair electrode are formed, the pixel electrode is separated from the thin film transistor or the scanning line, and is formed on the pixel electrode and the signal line. The method includes a step of forming a connection pattern for connecting the repair electrode. In order to adopt such a configuration, when the pixel electrode is short-circuited or leaked with the scan line, for example, the pixel electrode short-circuited or leaked with the scan line is disconnected from the thin film transistor or the scan line by cutting the source electrode. As the image signal supplied from the signal line is supplied to the pixel electrode, the dark spot defect and the bright spot defect are repaired, and a pseudo normal image is visually recognized. . Therefore, it can be sufficiently used as a liquid crystal display device.

  The method of manufacturing a liquid crystal display device according to the present invention includes a step of forming a capacitor line that constitutes a storage capacitor with the pixel electrode, and the pixel electrode and the repair electrode are formed after the pixel electrode and the repair electrode are formed. Forming a connection pattern for separating the non-overlapping pixel electrode and the repair electrode by separating the electrode electrode and the capacitive line from each other and the pixel electrode and the capacitive line not overlapping each other. It is characterized by that. By adopting such a configuration, when both the capacitor line and the pixel electrode are short-circuited or leaked at the overlapping portion, the overlapping portion where the capacitor line and the pixel electrode are short-circuited or leaked is removed from the pixel electrode. An image from the signal line is formed on the separated pixel electrode that does not overlap with the capacitor line by forming a connection pattern that connects the repaired electrode and the separated pixel electrode that does not overlap with the capacitor line. A signal can be supplied. Therefore, a pseudo-normal image can be visually recognized, and can be sufficiently used as a liquid crystal display device.

  The manufacturing method of the liquid crystal display device according to the present invention includes a step of separating the pixel electrode from the thin film transistor or the scanning line. With such a configuration, when the pixel electrode is not only short-circuited to the capacitor line but also the scanning line is short-circuited or leaked, for example, the source electrode is short-circuited or leaked by cutting the source electrode. Since the pixel electrode is disconnected from the thin film transistor or the scanning line and released, and the image signal is supplied to the pixel electrode through the connection pattern, the dark spot defect and the bright spot defect are repaired, A pseudo-normal image is visually recognized. Therefore, it can be sufficiently used as a liquid crystal display device.

  The method of manufacturing a liquid crystal display device according to the present invention includes a step of forming a connection pattern for connecting repair electrodes on both sides of a broken line on a signal line or a scanning line after the formation of the repair electrode. To do. By adopting such a configuration, even in the liquid crystal surface device in which the scanning line or the signal line is disconnected, the disconnected part can be repaired by the connection pattern, so that the TFT gate electrode and drain electrode after the disconnected part can be repaired. Since a scanning signal and an image signal supplied from the scanning line or the signal line are supplied, the line defect is repaired and a normal image is visually recognized. Therefore, the manufacturing yield of the liquid crystal display device is improved.

  The manufacturing method of the liquid crystal display device according to the present invention is characterized in that the connection pattern for connecting the repair electrodes on the scanning line is formed so as not to overlap the source electrode. By adopting such a configuration, the connection pattern has the same potential as the scanning line, that is, the gate electrode, but does not overlap the source electrode, so that an increase in the gate-source parasitic capacitance Cgs can be prevented. Therefore, even with such a repaired liquid crystal display device, the punch-out voltage can be reduced and uneven brightness can be suppressed, so that a liquid crystal display device with high display quality can be manufactured.

  In the method for manufacturing a liquid crystal display device according to the present invention, the connection pattern is formed by a laser CVD method or an ink jet method. By adopting such a configuration, it is not necessary to go through a photolithography process even in the connection pattern forming process because it is possible to directly draw the connection pattern without requiring a mask for forming the connection pattern. Contributes to improved productivity.

  As described above, the present invention provides a liquid crystal display device capable of repairing a display defect without damaging a signal line, a scanning line, or an insulating layer, and without reducing the aperture ratio. Can be provided. In addition, the present invention can provide a liquid crystal display device that can be repaired without requiring an extra photolithography process. Further, the present invention can provide a liquid crystal display device with high display quality and reliability even when such a liquid crystal display device is repaired.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[overall structure]
The active matrix type liquid crystal display device according to the present invention includes a liquid crystal panel in which liquid crystal is sandwiched between a cell array substrate and a counter substrate. FIG. 1 is a schematic configuration diagram of a liquid crystal panel portion of an active matrix type liquid crystal display device according to the present invention. FIG. 1A is a schematic plan view of the cell array substrate 101, and FIG. 1B is an equivalent circuit diagram for explaining the functions of the pixel unit 10 and the surrounding members. Note that in each drawing used for description in this specification, the scale or aspect ratio is appropriately changed for convenience.

  The cell array substrate 101 is formed with a plurality of scanning lines 72 extending in the X (row) direction and connected to the scanning line external terminals 74 and the gate electrodes of TFTs serving as switching elements in the pixel unit 10. ing. A scanning signal which is a signal for selectively switching the TFT is supplied to the TFT via the scanning line 72. A plurality of scanning line external terminals 74 corresponding to the plurality of scanning lines 72 are provided in the Y direction near the end of the cell array substrate 101. The scanning line external terminal 74 is connected to a predetermined terminal (not shown) of the scanning line driving device 70 such as a scanning line driver IC via an ACF (anisotropic conductor) (not shown).

  The cell array substrate 101 is formed with a plurality of signal lines 82 extending in the Y (column) direction and connected to the signal line external terminal 84 and the drain electrode of the TFT in the pixel unit 10. . An image signal is supplied to the TFT selected by the scanning signal via the signal line 82. A plurality of signal line external terminals 84 corresponding to the plurality of signal lines 82 are provided along the X direction near the end of the cell array substrate 101. The signal line external terminal 84 is connected to a predetermined terminal (not shown) of the signal line driver 80 such as a signal line driver IC via an ACF (not shown). The scanning line driving device 70 and the signal line driving device 80 may be disposed on the cell array substrate 101. In FIG. 1A, a capacitor line 28 (described later), which is a common line for the storage capacitor Cs, is not shown.

  In the display area 107 of the cell array substrate 101, the pixel unit 10 is arranged in a matrix form in an area defined by the scanning line 72 and the signal line 82 corresponding to each intersection of the scanning line 72 and the signal line 82. Is arranged. Reference numeral 10a denotes one pixel portion (hereinafter also referred to as a target pixel portion) related to the scanning line 72a and the signal line 82a, and adjacent pixel portions 10b, 10c, 10d, and the like are adjacent thereto. An adjacent scanning line 72c, which is a scanning line for the adjacent pixel portion 10c, is formed along the direction in which the scanning line 72a extends. An adjacent signal line 82b, which is a signal line for the adjacent pixel portion 10b, is formed along the direction in which the signal line 82a extends.

[Pixel part]
Next, a configuration of a pixel portion using a bottom gate TFT as a switching element and its peripheral portion will be described with reference to FIGS. 1B, 2 and 3A. 2 is a schematic plan view including the pixel unit 10 and its periphery according to the present embodiment, and FIG. 3A is a schematic cross-sectional configuration diagram in the direction of the arrow in the line AA ′ in FIG. It is. In FIG. 2, the gate insulating film 13 and the passivation layer 19 are removed for easy understanding, and the layer to be viewed is appropriately changed. The same applies to FIGS. 4 and 6 to 9 described later.

  The pixel unit 10 includes a TFT 20 and a pixel electrode 32. The TFT 20 is provided in the vicinity of the intersection between the scanning line 72 and the signal line 82. Further, the TFT 20 is formed integrally with the scanning line 72 on the substrate 11, and the gate electrode 12 which is a partial region on the scanning line 72 and the gate insulating film 13 which is the first insulating layer on the gate electrode 12. And a source electrode 25 and a drain electrode 26 formed on the semiconductor layer 14a. The region of the scanning line 72 that overlaps the TFT semiconductor layer 14 a in plan view generally functions as the gate electrode 12 of the TFT 20, whereby the gate electrode 12 is electrically connected to the scanning line 72.

  In addition, the substantially U-shaped drain electrode 26 branches off from the signal line 82 and is electrically connected to the drain region 16 which is a part of the semiconductor layer 14a. In the present embodiment, the drain electrode 26 branches off from a position where the signal line 82 and the scanning line 72 do not overlap in plan view. The source electrode 25 is electrically connected to the source region 15 which is a part of the semiconductor layer 14a, and is a transparent pixel formed from the transparent conductive layer 30 through the contact hole 23 which penetrates the passivation layer 19 which is the second insulating layer. The electrode 32 is electrically connected. The width of the wiring of the source electrode 25 is formed narrower than the width of the scanning line 72 and the signal line 82. The source electrode 25 passes from above the semiconductor layer 14 a over the end portion of the scanning line 72 via the gate insulating film 13 which is the first insulating layer, and further extends to the contact hole 23 on the gate insulating film 13. Is formed.

  As shown in FIG. 2, in the present embodiment, the repair electrode 24 is one pixel in a region that is part of the signal line 82 extending in the Y direction and defines one pixel portion. It is formed in two places per part, that is, as 24a1 and 24a2. Further, in a part of the scanning line 72 extending in the X direction and defining one pixel portion, the repair electrode 24 is formed at two positions per pixel portion, that is, as 24a3 and 24a4. Yes. Reference numeral 23 a is a contact hole for the repair electrode 24. Details of the repair electrode 24 will be described later.

  Further, the capacitor line 28 (also referred to as a storage capacitor common line or a storage capacitor common line) is a wiring connected in common to the storage capacitor Cs of each pixel portion in order to supply power to one electrode of the storage capacitor Cs27. The storage capacitor common signal having a predetermined voltage is supplied. In the present embodiment, the capacitor line 28 is formed so as to pass through the plurality of pixel portions 10 arranged in the vicinity of the center of the pixel electrode 32 along the direction in which the scan line extends, and the scan line 72 and the capacitor line 28. Are alternately arranged along the direction in which the signal lines extend with a predetermined interval. The capacitor line 28 also functions as one electrode of the storage capacitor Cs27, and a region where the pixel electrode 32 and the capacitor line 28 overlap in plan view constitutes the storage capacitor Cs27. Therefore, the other electrode of the storage capacitor Cs 27 is electrically connected to the pixel electrode 32 and the source electrode of the TFT 20. In the storage capacitor Cs27, the voltage of the image signal output from the signal line 82 is applied to the pixel electrode 32 through the TFT 20 in the ON state (selection period), and then the TFT 20 is in the OFF state (non-selection). The capacitance is provided to maintain the applied voltage substantially constant for a necessary time during the period.

  The common electrode (counter electrode) 34 is formed so as to face the pixel electrode 32 and is a transparent electrode common to each pixel. The common electrode 34 is generally formed on a counter substrate (not shown) in a TN (Twisted Nematic) type or VA (Vertical Alignment) type liquid crystal display device. A common signal having a predetermined voltage is applied to the common electrode 34 via a common electrode line (common electrode line) 35. Between the pixel electrode 32 and the counter electrode 34, the liquid crystal 99 which is an electro-optic material is sandwiched through an alignment film (not shown). Reference numeral 17 in FIG. 3A is a channel region of the TFT 20, and reference numerals 38 and 39 in FIG. 1B are a gate-source parasitic capacitance Cgs and a gate-drain parasitic capacitance Cgd, respectively. .

  The operation of the liquid crystal display device 100 including such a pixel unit 10 is, for example, as follows. The scanning line driving device 70 selects a pixel unit 10 to which the image signal from the signal line 82 should be written in units of rows based on a synchronization signal and other information of an image signal (not shown) input to the liquid crystal display device 100. Is output. Similarly, the signal line driving device 80 operates in synchronization with the scanning signal based on the luminance information of the image signal and supplies the image signal to the pixel unit 10 selected in the scanning period. Then, a voltage corresponding to the image signal from the signal line driving device is applied to the pixel electrode 32 via the TFT 20 in the selected pixel unit 10. As a result, an electric field is generated between a pair of electrodes including the pixel electrode 32 and the common electrode 34, and the orientation of the molecules of the liquid crystal 99 (the orientation of the liquid crystal molecules) is controlled by this electric field. Then, by utilizing this change in orientation, the light transmitting through the liquid crystal is modulated, thereby displaying an image or the like. In this way, a liquid crystal display device is configured.

  Next, the pixel portion and its periphery will be described in more detail with reference to FIG. As the substrate 11 of the cell array substrate 101, a plastic substrate can be used in addition to a glass substrate, a quartz substrate, etc., which are substrates having insulating properties and translucency. The scanning line 72, the gate electrode 12, the capacitor line 28, and the like are formed by patterning the first metal layer. The first metal layer may be, for example, a single layer film of AlNd, Al, or Mo, or a laminated film formed by combining AlNd, Al, Mo, and Cu. When the first metal layer contains Al and is connected to a transparent conductive layer such as ITO or an oxide semiconductor, the first metal layer has a laminated structure. For example, the lower layer is a metal containing Al such as AlNd. It is desirable that the upper layer connected to ITO or the like is a metal containing Mo. By adopting such a material and structure, a good electrical connection can be established with a repair electrode 24 made of ITO, which will be described later. The thickness of the first metal layer is desirably 100 nm to 500 nm, and more desirably 200 nm.

  As the material of the gate insulating film 13 which is the first insulating layer, a silicon oxide-based or silicon nitride-based SiNx, SiOx or SiOxNy single layer film, or a laminated film in which these are combined can be used. Thereby, an insulating and translucent layer can be formed. The gate insulating film 13 is provided so as to cover the scanning line 72 and the capacitor line 28 including the gate electrode 12 formed from the first metal layer. The thickness of the gate insulating film 13 is desirably 100 nm to 500 nm, and more desirably 250 nm to 300 nm. The semiconductor layer is generally made of amorphous Si, but is not particularly limited to this, and may be an oxide semiconductor containing any of In, Ga, and Zn. The semiconductor layer may be either amorphous or crystalline. The thickness of the semiconductor layer is not particularly limited, but is preferably 50 nm to 300 nm.

  The source electrode 25, the drain electrode 26, and the signal line 82 are patterned from the second metal layer. The material or structure of the second metal layer is not particularly limited and may be a single layer film of Al or Mo, but in order to avoid electric corrosion between the transparent conductive layer such as ITO and Al, for example, an upper layer in contact with ITO Is a laminated film (laminated wiring) formed by combining Al and Mo, such that Mo is Mo and the lower layer is Al. In the case where an oxide semiconductor is used as a material for the semiconductor layer, a semiconductor layer having a three-layer structure such as Mo—Al—Mo is more preferable. In this way, by using the second metal layer in which the uppermost layer and the lowermost layer are made of a metal containing Mo, the lower layer of the second metal layer is connected to the oxide semiconductor and the upper layer is connected to a transparent conductive layer such as ITO. Even in such a case, it is possible to prevent electric corrosion that tends to occur between Al and the oxide semiconductor layer, and between Al and a transparent conductive layer such as ITO, and to make a good and reliable electrical connection. . The thickness of the second metal layer is 100 nm to 500 nm, and more preferably 200 nm.

  The passivation layer 19 that is the second insulating layer is formed using silicon nitride or the like having insulating properties and translucency. The passivation layer 19 is formed so as to cover the TFT 20 and the signal line 82 including the source electrode 15 and the drain electrode 16 formed from the second metal layer. The pixel electrode 32 is formed by patterning the transparent conductive layer 30 formed on the passivation layer 19. Although it does not specifically limit as the material, For example, ITO is used. Further, the repair electrode 24 is formed together with the pixel electrode 32 by patterning the transparent conductive layer 30. The transparent conductive layer of the repair electrode 24 and the transparent conductive layer of the pixel electrode 32 are formed at positions separated from each other.

[Repair electrode]
Next, the repair electrode will be described. 3B and 3C are configuration diagrams of the repair electrode 24. FIG. FIG. 4B is an embodiment of the repair electrode formed on the signal line 82, and is a cross-sectional view taken along the line BB ′ in FIG. FIG. 3C is an embodiment of the repair electrode formed on the scanning line 72, and is a cross-sectional view taken along the line CC 'in FIG. The repair electrode 24 on the signal line shown in FIG. 3B is formed so as to cover the contact hole 23a that is an opening that penetrates the passivation layer 19 that is the second insulating layer and reaches the signal line 82 that is made of the second metal layer. This is a conductive layer made of ITO. The repair electrode 24 is simultaneously patterned in the process of patterning the pixel electrode 32 from the transparent conductive layer 30 made of ITO, and is formed in the same layer and the same process as the pixel electrode 32. The repair electrode 24 is electrically connected to the signal line 82 at the bottom of the contact hole 23a.

  Further, the repair electrode 24 on the scanning line shown in FIG. 4C is a contact that is an opening that penetrates the passivation layer 19 and the gate insulating film 13 that is the first insulating layer and reaches the scanning line 72 made of the first metal layer. It is a conductive layer made of ITO formed so as to cover the hole 23a. Similarly to the above, the repair electrode 24 formed on the scanning line is simultaneously patterned in the step of patterning the pixel electrode 32 from the transparent conductive layer 30 made of ITO. It is formed. The repair electrode 24 is electrically connected to the scanning line 72 at the bottom of the contact hole 23a. Thus, the repair electrode 24 is formed together with the formation of these TFTs and the like in the manufacturing process of the cell array substrate 101 including the TFT 20, the scanning line, the signal line, the capacitor line, the pixel electrode, and the like.

  In the present embodiment, as shown in FIG. 2, the repair electrode 24 is provided at four locations for each pixel unit 10. That is, in the pixel portion of interest 10a, the repair electrode 24a2 is located on the signal line 82a near the end remote from the TFT 20 of the pixel electrode 32 across the capacitor line 28, and the end of the pixel electrode 32 close to the TFT 20 Repair electrodes 24a1 are provided on the nearby signal lines 82a. On the scanning line 72a, the repair electrode 24a4 is interposed between the signal line 82a and the TFT 20 with the TFT 20 interposed therebetween, and the repair electrode 24a3 is disposed between the adjacent signal line 82b and the TFT 20 on the adjacent pixel portion 10b. , Each provided.

  The formation position and the number of repair electrodes 24 on the signal line are arbitrary, and are not limited to two locations per pixel portion as described above. For example, when the formation position of the capacitor line 28 is formed not near the center of the pixel portion 10a but near one of the adjacent scanning lines, the repair electrode 24 on the signal line has the effect of the present invention. As long as it plays, only one location on the signal line and close to the center of the pixel electrode 32 may be provided. Further, the position and number of the repair electrodes 24 on the scanning line are not limited to two locations per pixel portion as described above. In addition, when the distance between the repair electrode 24 and the repair electrode 24 is shortened, the resistance of the connection pattern 21 described later can be reduced. Further, when the distance between the repair electrodes is increased, disconnection or the like can be repaired over a wide range even when the number of repair electrodes 24 is small. In addition, the distance between the repair electrodes may be all equal, or part or all may be unequal.

  In addition, the formation position of the repair electrode 24 is not limited to the pixel portion 10 inside the display area 107 as described above, but other positions on the scanning line 72 and the signal line 82, for example, the periphery outside the display area 107 You may form on the scanning line and signal line which were formed in the part. Further, it can also be provided on wiring other than the scanning line and the signal line, for example, a transfer wiring (not shown) for transferring a synchronization signal, a control signal, and the like, and the capacitor line 28. The structure of the repair electrode 24 is the same as that shown in FIG. 3C if these wirings are formed from the first metal layer, and the structure shown in FIG. It is the same. The repair electrode 24 may be provided in a region where the capacitor line 28 and the signal line 82 intersect, and the structure of the repair electrode 24 in this case is the same as that shown in FIG.

[Repair method]
Next, the repair method will be described with reference to FIGS. 4 and 5A. FIG. 4 is a configuration diagram of the liquid crystal display device according to the present embodiment. FIG. 5A is a schematic cross-sectional view of the repair electrode 24 formed on the signal line, and is a cross-sectional view taken along the line DD ′ in FIG. Reference numeral 21 is a conductive connection pattern formed in the repair process according to the present embodiment.

  As an example, a repair method in a TN type normal white mode liquid crystal display device having a defect in which the pixel electrode 32 is short-circuited with the scanning line 72 for some reason will be described. In a liquid crystal display device in which two polarizing plates are arranged so that their transmission axes are orthogonal to each other, and a TN liquid crystal having a twist angle of 90 degrees is sandwiched between these two polarizing plates, no electric field is applied to the liquid crystal Is a white display (bright display) that transmits light from the backlight. When an electric field corresponding to black display is applied to the liquid crystal, the light from the backlight is absorbed to display black (dark display). Normal white mode LCD is displayed.

  In such a TN type normal white mode liquid crystal display device, when a defect such as a short circuit with the scanning line 72 occurs for some reason, the pixel electrode 32 is supplied with a normal voltage based on the image signal. In other words, the potential of the pixel electrode 32 is always almost the same as the potential of the scanning line 72. Since the voltage level of the scanning signal supplied to the scanning line 72 is generally different from the voltage level of the common signal applied to the common electrode 34 and the potential difference between the two is relatively large, the pixel electrode having such a short-circuit defect is also present. An electric field corresponding to the difference between the scanning signal potential and the common electrode potential is applied between the common electrode 34 and the common electrode 34. Therefore, when an image is displayed on such a liquid crystal display device, the pixel portion having such a short-circuit defect is darkly displayed, and when the peripheral pixel portion is brightly displayed, it is visually recognized as a so-called dark spot defect. The

  Next, the repair method according to the present embodiment will be described taking the dark spot defect of such a TN type normal white mode liquid crystal as an example. First, after the cell array substrate 101 is formed, information such as the presence / absence of a dark spot defect and a defect position is acquired in an inspection process. A specific defect inspection method will be described later. Next, when there is a dark spot defect caused by a short circuit between the pixel electrode 32 and the scanning line 72, the connection between the TFT 20 or the scanning line 72 and the pixel electrode 32 is disconnected. Specifically, for example, when the pattern layout is as shown in FIG. 4, the source electrode is cut by irradiating the cut portion 98 of the source electrode 25 with laser light. As a result, the pixel electrode 32 is electrically released. The cut point 98 is not particularly limited as long as it does not depart from the gist of the present invention as long as it can be separated from at least the pixel electrode 32 from the short-circuited point.

  Next, a connection pattern 21 is formed by growing a metal made of W (tungsten) or Mo from the repair electrode 24a1 to the end of the pixel electrode 32 by laser CVD or the like. Since the repair electrode 24a1 is electrically connected to the signal line 82a at the bottom thereof, the signal line 82a and the pixel electrode 32 are electrically connected via the connection pattern 21. As a result, the image signal supplied to the signal line 82a is supplied to the pixel electrode 32, and the potential of the pixel electrode 32 is always the same as the potential of the signal line 82a. Therefore, when an image is displayed on such a liquid crystal display device, the pixel unit 10a related to the repaired pixel electrode 32 displays a display having a gradation corresponding to the average voltage of the image signal supplied from the scanning line 82a. It will be visually recognized, and will not be visually recognized as a dark spot defect, but will be visually recognized as a pixel portion that performs a normal display with no defect.

  When a metal made of Mo or the like is used as the material of the connection pattern 21, since the repair electrode 24 and the pixel electrode 32 are both made of ITO, these and the connection pattern 21 are good and highly reliable. Connection can be made. The width of the connection pattern 21 is not particularly limited, but may be several μm, for example, about 5 μm. Further, it is desirable to grow the connection pattern 21 so that the connection pattern 21 overlaps at the end of the pixel electrode 32. The width and length of the overlap are not particularly limited, but may be about 3 μm. If the length of the overlap with the pixel electrode 32 is about this level, the connection pattern 21 can be formed under a black matrix (hereinafter referred to as BM) (not shown), that is, inside the region overlapping with the BM. The light shielding part is not increased by the pattern 21. Therefore, there is no problem that the aperture ratio is lowered by the formation of the connection pattern 21.

  Note that BM is a light shielding layer formed of metal or black resin, and is formed on the counter substrate together with a color filter, for example. The black matrix is formed in a lattice shape so as to cover at least the scanning lines 72 and the signal lines 82 in the display area 107, the area between them and the pixel electrode 32, and the peripheral edge of the pixel electrode 32. When the TFT 20 is not formed on the scanning line 72, the TFT 20 is also formed so as to cover it. As described above, the present invention can repair the display defect of the dark spot defect of the pixel portion by adopting such a configuration. That is, when such a display defect is found, the repair electrode 24 is already formed on the wiring of the signal line 82, so that one end of the connection pattern 21 is connected to the repair electrode and the other end is connected. Such display defects can be repaired by connecting to the pixel electrode of the pixel portion to be repaired.

  The repair electrode 24 is formed from the transparent conductive layer in the same layer and the same process as the pixel electrode in the normal TFT and pixel electrode formation process, and is formed in advance together with the opening on the scanning line or the signal line. Therefore, even when these display defects are found after the formation of the pixel electrode, the cell array substrate having the display defect is again subjected to the photolithography process in order to form a contact hole for repair as in the prior art. An extra step of returning is unnecessary. Therefore, the number of photolithography processes is not increased and the productivity is improved. In addition, since the contact hole is not newly opened in the cell array substrate after the manufacturing process is almost completed as in the prior art, the yield reduction due to the contact hole opening cannot occur.

  Further, according to the present invention, a repair electrode that is electrically connected to a scanning line or a signal line is formed in advance on the scanning line or the signal line. As in the conventional example, a pixel electrode made of ITO or the like is used for repair. The pixel electrode and the signal line are not welded by a laser by destroying the insulating film between the portion and the signal line. Therefore, the long-term reliability can be improved without damaging the metal layer such as the lower signal line by the laser beam. Furthermore, in the present invention, since the repair electrode 24 is formed on the scanning line or the signal line, the repair electrode is usually formed under the black matrix. Therefore, the aperture ratio is not lowered by providing the repair electrode. Even when the connection pattern 21 is repaired, since the connection pattern is only formed in the vicinity of the repair electrode, the connection pattern can also be formed under the black matrix.

  Therefore, the aperture ratio is not reduced by the connection pattern. Even if the connection pattern is formed to extend to the outside of the black matrix, in the present invention, the connection pattern is not formed in advance so as to overlap the pixel electrode in all the pixels as in the conventional example, but a dark spot defect. Alternatively, since it is sufficient to form only in a pixel portion having a display defect such as a bright spot defect, a decrease in aperture ratio can be minimized. Further, since the repair electrode 24 is covered with the transparent conductive layer after the insulating layer on the scanning line or the signal line is opened, the scanning line or the signal line which is a metal layer is not exposed in the opening. Therefore, also in this respect, the long-term reliability of the liquid crystal display device can be improved.

[Production method]
Next, with reference to FIG. 3, FIG. 4 and FIG. 5 (a), a manufacturing method of the liquid crystal display device according to the present embodiment will be described in the order of steps. First, after forming a first metal layer on the substrate 11 to be the cell array substrate 101, the first metal layer is patterned to form a pattern such as the scanning line 72, the capacitor line 28 and the like including the gate electrode 12 (first Step (first PEP)). A method for forming the first metal layer is not particularly limited, but a sputtering method may be used. The materials and structures of the first metal layer and the substrate 11 are as described above.

  Next, the gate insulating film 13 is formed on the entire surface of the substrate by a CVD method or the like (second step). Thereby, the pattern formed of the first metal layer is covered with the gate insulating film 13. Next, the semiconductor layer 14 is formed. The method for forming the semiconductor layer is not particularly limited, but plasma CVD is used in the case of amorphous Si, and sputtering is performed in the case of an oxide semiconductor such as an oxide semiconductor containing In, Ga, and Zn (hereinafter referred to as IGZO). A scheme can be used. After the semiconductor layer is formed, the semiconductor layer 14a is formed by patterning to form the semiconductor layer 14a to be the semiconductor layer of the TFT 20 (third step (second PEP)).

  Next, a second metal layer is formed and patterned to form the source electrode 25, the drain electrode 26, the signal line 82, and the like (fourth step (third PEP)). Although the formation method of a 2nd metal layer is not specifically limited, You may use a sputtering system. The material and structure of the second metal layer are as described above. Next, a passivation layer 19 is formed on the entire surface of the substrate by CVD using silicon nitride or the like. As a result, the second metal layer and the like are covered with the passivation layer 19. Then, patterning is performed by etching, and a part of the pattern is removed to form a contact hole 23 for connecting the pixel electrode 32 and the source electrode 25, a contact hole 23a that is an opening for the repair electrode 24, and the like. Form (fifth step (fourth PEP)). Since the contact hole 23a for the repair electrode 24 is formed by this PEP, it is not necessary to return to the photolithography process again in a process subsequent to this PEP for repair, and productivity is improved.

  Next, the transparent conductive layer 30 is formed by a sputtering method or the like. After forming the transparent conductive layer 30, the pixel electrode 32, the repair electrode 24, etc. are formed by patterning this (6th step (5th PEP)). The repair electrode 24 is formed so as to cover the contact hole 23a. In addition, since the repair electrode 24 is formed of the same layer and the same PEP from the transparent conductive layer 30 that forms the pixel electrode 32 in this PEP, the repair electrode 24 is again formed in the film-forming process in the process after this PEP for repair. Productivity is improved without the need to return.

  Thus, the cell array including the pixel unit 10 including the bottom gate type TFT 20 and the pixel electrode 32, various wirings such as the capacitor line 28, the scanning line 72, the signal line 82, and the repair electrode 24 on the substrate 11. A substrate 101 is formed. Next, the cell array substrate 101 formed in this way is inspected for defects (seventh step). The cell array substrate is in a state where the pixel electrode 32 is formed at this stage, and is not yet sealed with the counter substrate and the liquid crystal is not sealed. Can be detected including its position. For example, in the EB tester (Electron Beam Tester) method, a predetermined voltage is applied to the capacitor line 28, and the pixels on the cell array substrate 101 are scanned using the scanning line driving device 70 and the signal line driving device 80 (see FIG. 1). After applying a voltage to the electrode 32 and holding the charge in the storage capacitor Cs, each pixel electrode 32 is irradiated with an electron beam. Then, the amount of secondary electrons emitted from each pixel electrode 32 by the electron beam is detected. Since the amount of secondary electrons varies depending on the amount of charge held in the pixel electrode, it is possible to distinguish between a normal pixel and a defective pixel that cannot hold charge due to a short circuit or disconnection.

  And when a defect is discovered, a repair process is performed (8th step). In the defect defect repairing process, as described above, for example, the source electrode 25 is cut to cut off the electrical connection between the TFT 20 or the scanning line 72 and the pixel electrode 32, and the repair electrode 24a1 is formed by laser CVD or the like. A connection pattern 21 made of a conductive material is formed between the pixel electrode 32 and the pixel electrode 32. Thereby, the pixel electrode 32 is electrically released from the TFT 20 and the scanning line 72, and the signal line 82a and the pixel electrode 32 are electrically connected. Display defects such as bright spot defects and disconnection, which will be described later, can also be repaired in this step.

  Next, the cell array substrate 101 thus repaired and the counter substrate provided with a color filter or the like are subjected to an alignment treatment or the like, and then both substrates are bonded together with a sealing material. As the sealing material, for example, an ultraviolet curable sealing material such as a photo-curing acrylic resin is used. Liquid crystal is injected between the liquid crystal substrates thus sealed, and an optical member such as a drive circuit, a polarizing plate, or a backlight is attached to complete the liquid crystal display device 100 (9th step). Since the manufacturing method of the liquid crystal display device according to the present embodiment has such a configuration, it is possible to provide a liquid crystal display device in which defects are repaired. The liquid crystal display device manufactured by such a manufacturing method has already been described. There are the following effects.

The method of forming the connection pattern 21 in the repair process is not particularly limited, but a laser CVD apparatus can be used. The laser light source may be a laser such as a carbon dioxide gas laser. For example, the third harmonic (wavelength 349 nm) of a YLF laser using lithium yttrium fluoride (LiYF ₄ ) doped with Nd ions may be used. it can. The wavelength of the laser beam is not particularly limited as long as it does not depart from the spirit of the present invention. As the source gas, a W compound such as WC (CO) ₆ can be used in the case of forming a W connection pattern, but other gases containing Mo, Cr, or the like may be used. As the carrier gas, Ar is used, but nitrogen or the like can also be used. If the average output of the laser beam is set to 50 mW or more, for example, the connection pattern 21 made of W having a wiring width of about 3 to 10 μm and a film thickness of about 250 to 350 nm can be formed.

  The method of forming the connection pattern 21 is not limited to such a laser CVD method. For example, fine particles such as Au and Ag having a particle diameter of about several nanometers as a material of the connection pattern 21 are dispersed in an organic solvent. The connection pattern 21 may be formed by using a paste and patterning the connection pattern by an ink jet method or the like and then heating and drying. Both the laser CVD method and the ink jet method do not require a mask and can directly draw a pattern. Therefore, it is not necessary to go through a photolithography process in forming a connection pattern, which contributes to an improvement in productivity.

[Application Example 1]
Next, a bright spot defect repair method will be described by taking a TN type normal white mode liquid crystal display device as an example as described above. In this application example, the description will focus on the parts different from the embodiment relating to the defect defect repair method described above, and the same or equivalent components as those described in the above embodiment are denoted by the same reference numerals. A description thereof will be omitted.

  FIG. 6 is a configuration diagram of the liquid crystal display device according to the present embodiment. In this application example, repair of a bright spot defect that occurs when the pixel electrode 32 is short-circuited to the capacitor line 28 will be described. For example, the capacitor line 28 is driven at the same potential as the common electrode 34. In the non-selection period that occupies most of one scanning period, the TFT 20 is in an off state. Therefore, when the pixel electrode 32 is short-circuited with the capacitor line 28, the pixel electrode 32 and the capacitor line 28 are It becomes the same potential. Accordingly, in such a case, the potential of the pixel electrode 32 and the potential of the common electrode 34 are the same, and there is no electric field between the two electrodes. Therefore, in the case of a TN type normal white mode liquid crystal display device, such a defective pixel transmits light from the backlight and displays white. Therefore, when an image is displayed on such a liquid crystal display device, when the pixel portion around the pixel portion having such a short-circuit defect is darkly displayed, the pixel portion having the short-circuit defect is brightly displayed. It is visually recognized as a so-called bright spot defect. Note that, during the selection period of the TFT 20, the TFT 20 is turned on, so that the signal line 82a, the pixel electrode 32, and the capacitor line 28 are short-circuited, and the potential of the signal line 82a is also subject to fluctuations.

  When such a bright spot defect exists, first, the TFT 20 or the scanning line 72 and the pixel electrode 32 are disconnected. Specifically, for example, the source electrode 25 is cut by irradiating the cut portion 98 of the source electrode 25 with laser light. Thereby, the pixel electrode 32 becomes non-conductive with the TFT 20 or the scanning line 72 regardless of whether the TFT 20 is on or off, and is electrically released. Furthermore, when a short circuit occurs in a region where both the pixel electrode 32 and the capacitor line 28 overlap in plan view, the capacitor line 28 and the pixel electrode 32 are short-circuited by irradiating the cut portions 98g and 98h with laser light. The pixel electrode is separated from the portion and separated into three pixel electrodes 32f, 32g, and 32h. As a result, the pixel electrode 32 f becomes a pixel electrode that overlaps the capacitor line 28, and the pixel electrodes 32 g and 32 h become separated pixel electrodes that do not overlap the capacitor line 28 of the pixel electrode 32. As a result, the separated pixel electrodes 32g and 32h become non-conductive with the capacitor line 28 and are electrically released from the capacitor line 28.

  In FIG. 6, the cut points 98g and 98h are provided at two places on both sides of the capacitor line 28. However, the present invention is not limited to this, and at least a short-circuit point between the capacitor line 28 and the pixel electrode 32 can be cut. As long as it does not deviate from the gist of the present invention, it may be one place, and the location of the cutting part is not particularly limited. Next, a metal made of W, Mo, or the like is grown from the repair electrodes 24a1 and 24a2 to the end of the pixel electrode 32 by a laser CVD method or the like to form connection patterns 21 and 21a. Since the repair electrode 24 is electrically connected to the signal line 82a at the bottom, the signal line 82a and the pixel electrodes 32g and 32h are electrically connected via the connection patterns 21 and 21a. As a result, an image signal supplied to the signal line 82a is supplied to the pixel electrodes 32g and 32h, and the potentials of the pixel electrodes 32g and 32h become the same as the potential of the signal line 82a. When an image is displayed on a liquid crystal display device, in the pixel unit 10a related to the repaired pixel electrode 32, a display having a gradation according to the average voltage of the image signal supplied from the scanning line 82a is visually recognized. Therefore, it is not visually recognized as a bright spot defect, but is visually recognized as a pixel portion that performs pseudo-normal display without any defect. When the TFT 20 is operating normally, the pixel electrode 32 is cut at the cut points 98g and 98h without cutting the source electrode at the cut point 98, and only the pixel electrode 32h is connected by the connection pattern 21a. It may be simply connected to the repair electrode 24a2.

  The position and number of repair electrodes on the signal line are not particularly limited. For example, as shown in the figure, when the capacitor line 28 is formed near the center of the pixel electrode 32 along the direction in which the scanning line 72 extends, two repair electrodes are provided for each pixel portion on the signal line 82a. It is desirable to provide 24a2 and 24a1 on both sides of the intersection between the capacitor line 28 and the signal line 82a. Thus, even if the pixel electrode 32 is cut at two places at the cut places 98g and 98h, both the pixel electrodes 32g and 32h on both sides of the capacitor line 28 are connected from the signal line 82a through the connection patterns 21 and 21a. An image signal can be supplied. Therefore, the substantial reduction of the pixel portion of the pixel portion 10a can be minimized.

  Further, when only one repair electrode 24 on the signal line 82 is formed per pixel portion, the repair electrode 24 is provided on or near the intersection of the capacitor line 28 and the signal line 82, and In this way, the pixel electrode is cut on both sides of the capacitor line 28, and a connection pattern connected to both of the cut pixel electrodes 32g and 32h is grown from one repair electrode 24, whereby the signal line 82a and the pixel electrode 32g, Both of 32h may be conducted. When the capacitor line 28 is formed close to one of the scanning lines 72a and 72c, only the repair electrode at a position remote from the capacitor line 28 is used among the repair electrodes 24a2 and 24a1. May be.

  Although the description has been made with the example of the normal white mode so far, the present invention can also be applied to a normal black mode liquid crystal display device in which the transmission axes of two polarizing plates are provided in parallel. In a normal black mode liquid crystal display device, when no electric field is applied to the liquid crystal, light from the backlight is absorbed to display black (dark display), and when an electric field corresponding to white display is applied to the liquid crystal, the backlight emits light. Light is transmitted and white display (bright display) is obtained. Accordingly, the defect mechanism of the bright spot defect and the dark spot defect is also opposite to that of the normal white mode liquid crystal display device, but the repair method described in this embodiment can also be applied to the normal black mode liquid crystal display device. .

[Application 2]
Next, a repair method when the signal line 82 is disconnected will be described. In this application example, the description will focus on parts that are different from the above-described embodiment, and the same or equivalent components as those described in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be omitted. .

  FIG. 7 is a configuration diagram of the liquid crystal display device according to the present embodiment. For example, when the signal line 82a is disconnected at the disconnection point 49, a line defect occurs as described above. In this case, the two repair electrodes closest to the disconnection point 49 are electrically connected by the connection pattern 21 grown by the laser CVD method or the like. Thereby, the disconnection defect is repaired. That is, the metal made of W, Mo, or the like, from one repair electrode 24a1 close to the disconnection point 49 to the other repair electrode 24a2 that is close to the disconnection point 49 and sandwiches the disconnection point 49 and faces the one repair electrode 24a1. The connection pattern 21 is formed by growing across the disconnection point 49. Since the two repair electrodes 24a1 and 24a2 are electrically connected to the signal lines 82a1 and 82a2 at the bottoms thereof, the connection of the signal lines that have been disconnected through the connection pattern 21 is repaired.

  The position and number of repair electrodes are not particularly limited, but it is desirable to provide such a disconnection defect at a plurality of locations per pixel portion as already described. By doing in this way, the space | interval between repair electrodes 24 becomes short, and the influence by the resistance of the connection pattern 21 can be decreased. Although not shown, a plurality of connection patterns may be formed in different directions from one repair electrode. For example, when a disconnection of a signal line and a dark spot defect of a pixel electrode occur simultaneously in one pixel portion, a connection pattern extending in the signal line direction for repairing the disconnection and a pixel electrode for repairing the dark spot Both extending connection patterns may be formed so as to be connected to a certain repair electrode 24.

[Application Example 3]
Next, a repair method when the scanning line 72 is disconnected will be described with reference to FIGS. 8 and 5B. In this application example, the description will focus on parts that are different from the above-described embodiment, and the same or equivalent components as those described in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be omitted. . FIG. 8 is a configuration diagram of the liquid crystal display device according to the present embodiment. FIG. 5B is a schematic cross-sectional view of the repair electrode 24 formed on the scanning line, and is a cross-sectional view taken along the line EE ′ of FIG.

  For example, as shown in FIG. 8, when the scanning line 72 is disconnected at the disconnection point 49 between the repair electrode 24a3 and the adjacent signal line 82b and separated into the scanning line 72a1 and the scanning line 72a2, As described above, line defects occur. The repair electrode 24a3 is a repair electrode provided on the scanning line 72a1 between the TFT 20 of the target pixel portion 10a and the adjacent signal line 82b. The repair electrode 24b4 is a repair electrode provided on the scanning line 72a2 between the TFT 20 (not shown) in the adjacent pixel portion 10b and the adjacent signal line 82b.

  In this case, the disconnection defect can be repaired by electrically connecting the two repair electrodes on the scanning line closest to the disconnection point 49 with the disconnection point 49 interposed therebetween by a laser CVD method or the like. . That is, a metal made of W, Mo, or the like is approached from one repair electrode 24a3 close to the disconnection location 49, close to the disconnection location 49, and the other repair electrode 24b4 facing the one repair electrode 24a3 across the disconnection location 49. The connection pattern 21 is formed by growing over the disconnection point 49 until the connection pattern 21 is reached. Since the two repair electrodes 24a3 and 24b4 are both electrically connected to the scanning lines 72a1 and 72a2 at the bottoms thereof, the disconnection of the scanning lines disconnected through the connection pattern 21 is repaired. The connection pattern 21 intersects with the adjacent signal line 82b. However, since the passivation layer 19 is formed between the adjacent signal line 82b and the connection pattern 21, there is no short circuit with the adjacent signal line 82b. In addition, since the step due to the adjacent signal line 82b is also relaxed by the passivation layer 19, the connection pattern 21 itself is hardly disconnected at the step.

  The position and the number of repair electrodes are not particularly limited, but it is desirable to provide such a disconnection defect at a plurality of locations per pixel portion as already described. By doing in this way, the space | interval of the repair electrode 24 becomes short, and the influence by the resistance of the connection pattern 21 can be decreased. Accordingly, in this application example, only one repair electrode 24 is provided between the TFT 20 and the adjacent signal line 82b, but a plurality of repair electrodes 24 may be provided.

[Application Example 4]
Next, another repair method when the scanning line 72 is disconnected will be described. In this application example, the description will focus on parts that are different from the above-described embodiment, and the same or equivalent components as those described in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be omitted. .

  FIG. 9 is a configuration diagram of the liquid crystal display device according to the present embodiment. For example, when the scanning line 72 is disconnected at the disconnection point 49 between the TFT 20 and the repair electrode 24a3, the scanning line 72 is separated into the scanning line 72a1 and the scanning line 72a, and the line defect as described above. Will occur.

  In this case, laser CVD is performed in such a way that the two repair electrodes 24a3 and 24a4 on the scanning line closest to the breakage point 49 sandwiching the breakage point 49 do not overlap with the source electrode 25 of the TFT 20 in plan view. Disconnection defects can be repaired by electrical connection by a method or the like. That is, a metal made of W, Mo, or the like is approached from one repair electrode 24a3 close to the disconnection point 49, close to the disconnection point 49, and the other repair electrode 24a4 facing the one repair electrode 24a3 across the disconnection point 49. The connection pattern 21 is formed by growing up to. Since these two repair electrodes 24a3 and 24a4 are both electrically connected to the scanning lines 72a2 and 72a1 at the bottoms thereof, the scanning lines that have been disconnected through the connection pattern 21 can be repaired. .

  Then, as shown in the figure, it is desirable that the connection pattern 21 is formed so as to bypass the TFT 20 through a path that does not overlap the source electrode 25 of the TFT 20 in plan view. Since the scanning lines 72a1 and 72a2 and the connection pattern 21 are electrically connected to each other at the bottom of the repair electrode, by forming the connection pattern 21 so as to detour in this manner, the source electrode 25 and the connection pattern 21 are overlapped in a plane. An increase in the gate-source capacitance Cgs38 can be avoided, and the occurrence of uneven brightness due to a punch-through voltage or the like can be prevented. Therefore, even a repaired liquid crystal display device can maintain its display quality.

  As described above, the present invention can repair not only the dark spot defect in the pixel portion but also the display defect such as the bright spot defect or the disconnection of the scanning line or the signal line. That is, when such a display defect is found, the repair electrode 24 is already formed on the wiring of the scanning line 72 or the signal line 82, so that one end of the connection pattern 21 is formed on the repair electrode. These display defects can be repaired by connecting the other end to a pixel electrode of a pixel portion to be repaired or another repair electrode formed on a wiring such as a signal line. In addition, the same effects as described above can be obtained.

[Application Example 5]
The present invention can also be applied to a liquid crystal display device (not shown) using a top gate type TFT. When a top gate type TFT is used, the manufacturing process thereof is as follows, for example. First, a source electrode made of a first metal layer and connected to a thin film transistor, a signal line connected to the drain electrode and the drain electrode are formed on the substrate (first step). Next, a semiconductor layer of a thin film transistor is formed on the source electrode and the drain electrode (second step). Next, a scanning line and a gate electrode are formed from the second metal layer via the first insulating layer formed on the first metal layer and the semiconductor layer (third step). Next, a second insulating layer is formed on the second metal layer (fourth step). Next, the first insulating layer and the second insulating layer formed on the signal line and the opening reaching the signal line or the second insulating layer formed on the scanning line and the scanning line are reached. Openings are formed (5 steps). Next, a pixel electrode made of a transparent conductive layer connected to the source electrode is formed on the second insulating layer, and a repair electrode made of a transparent conductive layer covering the opening is formed (sixth step). A connection pattern for repairing display defects can be connected to the repair electrode.

  By using such a manufacturing method, a top gate type TFT and a pixel electrode are formed, and a cell array substrate in which a repair electrode is formed on a signal line and a scanning line is manufactured in the same manner as described above. can do. Therefore, even in a liquid crystal display device using a top gate type TFT, when a display defect such as a bright spot defect, a dark spot defect, or a disconnection defect occurs, it can be repaired in the same manner as described above. The same effect is produced.

  The present invention is not limited to the defect inspection method described in this embodiment. Further, although a TN liquid crystal display device has been described, the present invention is applied to a liquid crystal display device having operation modes of VA type, IPS (In-Plane Switching) type, and FFS (Fringe Field Switching) type other than the TN type. Even applicable. Further, although specific embodiments shown in the drawings have been described, the present invention is not limited to the embodiments shown in the drawings, and any configuration known so far as long as the effects of the present invention are exhibited. However, it goes without saying that it can be adopted.

It is a typical block diagram of the liquid crystal display device which is one embodiment. 1 is a schematic configuration diagram of a pixel portion according to an embodiment of the present invention. 1 is a schematic cross-sectional configuration diagram of a pixel portion and a repair electrode according to an embodiment of the present invention. 1 is a schematic configuration diagram of a pixel portion according to an embodiment of the present invention. It is a rough section lineblock diagram showing the repair state which is an embodiment of the invention. 1 is a schematic configuration diagram of a pixel portion according to an embodiment of the present invention. 1 is a schematic configuration diagram of a pixel portion according to an embodiment of the present invention. 1 is a schematic configuration diagram of a pixel portion according to an embodiment of the present invention. 1 is a schematic configuration diagram of a pixel portion according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Pixel part 11 ... Substrate 12 ... Gate electrode 13 ... Gate insulating film (1st insulating layer)
DESCRIPTION OF SYMBOLS 14 ... Semiconductor layer 14a ... Semiconductor layer of TFT 15 ... Source region 16 ... Drain region 19 ... Passivation layer (2nd insulating layer)
20 ... TFT (Thin Film Transistor)
DESCRIPTION OF SYMBOLS 21 ... Connection pattern 23 ... Contact hole 23a ... Contact hole 24, 24a1, 24a2, 24a3, 24a4 ... Repair electrode 25 ... Source electrode 26 ... Drain electrode 27 ... Storage capacity Cs
28 ... Capacitor line 30 ... Transparent conductive layer 32, 32f, 32g, 32h ... Pixel electrode 34 ... Common electrode (counter electrode)
35 ... Common electrode line 49 ... Disconnection location 72, 72a, 72c ... Scanning line 82, 82a, 82b ... Signal line 98, 98g, 98h ... Disconnection location 100 ... Liquid crystal display device 101 ... Cell array substrate 103 ... Counter substrate 107 ... Indicated Area

Claims (17)

A thin film transistor formed near the signal line and the scanning line and connected to the scanning line and the signal line;
An insulating layer provided on the scanning line or the signal line, the opening having an opening reaching the scanning line or the signal line;
A pixel electrode comprising a transparent conductive layer formed on the insulating layer and connected to the thin film transistor;
A repair electrode formed from the transparent conductive layer so as to cover the opening;
A liquid crystal display device comprising a connection pattern connected to the repair electrode and repairing a display defect. The liquid crystal display device according to claim 1, wherein the repair electrode is provided in the vicinity of the pixel electrode. A capacitor line that forms a storage capacitor with the pixel electrode;
3. The liquid crystal display device according to claim 1, wherein the repair electrode is formed on both sides of the intersection of the signal line and the capacitance line on the signal line. 4. The liquid crystal display according to claim 1, wherein the connection pattern is connected to a repair electrode formed on the signal line and a pixel electrode of a pixel portion having a display defect. 5. apparatus. The thin film transistor is formed on the scanning line,
3. The liquid crystal display device according to claim 1, wherein the repair electrode is provided on the scanning line between the thin film transistor and the signal line. The thin film transistor is formed on the scanning line, and the repair electrode is provided on the scanning line between the thin film transistor and an adjacent signal line adjacent to the signal line. Item 3. A liquid crystal display device according to item 1 or 2. The said connection pattern has connected the said repair electrodes in the both sides of the disconnection location of the said signal line or the said scanning line, The Claim 1 thru | or 3, 5 or 6 characterized by the above-mentioned. A liquid crystal display device according to claim 1. 8. The liquid crystal display device according to claim 1, wherein the connection pattern is formed under a black matrix. 9. The liquid crystal display device according to claim 1, wherein the transparent conductive layer is made of a conductive material containing ITO, and the connection pattern is made of a metal containing W or Mo. Forming a gate electrode and a scanning line made of a first metal layer and connected to the thin film transistor on the substrate;
A second step of forming a semiconductor layer of the thin film transistor on the gate electrode through a first insulating layer;
Forming a source electrode and a drain electrode made of a second metal layer on the semiconductor layer, and forming a signal line connected to the drain electrode on the first insulating layer;
A fourth step of forming a second insulating layer on the second metal layer;
The signal line passing through the first insulating layer and the second insulating layer formed on the scanning line and through the second insulating layer formed on the signal line or an opening reaching the scanning line A fifth step of forming an opening reaching
Forming a pixel electrode made of a transparent conductive layer connected to the source electrode on the second insulating layer, and forming a repair electrode made of the transparent conductive layer covering the opening. A method for manufacturing a liquid crystal display device. Forming a source electrode made of a first metal layer, connected to the thin film transistor, a drain electrode, and a signal line connected to the drain electrode on the substrate;
A second step of forming a semiconductor layer of the thin film transistor on the source electrode and the drain electrode;
A third step of forming a scanning line and a gate electrode made of a second metal layer via a first insulating layer formed on the first metal layer and the semiconductor layer;
A fourth step of forming a second insulating layer on the second metal layer;
The scanning line passes through the first insulating layer formed on the signal line and the second insulating layer and reaches the signal line or the second insulating layer formed on the scanning line. A fifth step of forming an opening reaching
Forming a pixel electrode made of a transparent conductive layer connected to the source electrode on the second insulating layer, and forming a repair electrode made of the transparent conductive layer covering the opening. A method for manufacturing a liquid crystal display device. After forming the pixel electrode and the repair electrode, separating the pixel electrode from the thin film transistor or the scanning line and forming a connection pattern for connecting the pixel electrode and the repair electrode formed on the signal line 12. The method of manufacturing a liquid crystal display device according to claim 10 or claim 11, comprising: A step of forming a capacitor line constituting a storage capacitor with the pixel electrode, and after forming the pixel electrode and the repair electrode, the pixel electrode and a portion where the pixel electrode and the capacitor line overlap with the pixel 12. The method of claim 10, further comprising the step of separating the electrode and the capacitor line into portions that do not overlap and forming a connection pattern that connects the non-overlapping pixel electrode and the repair electrode. The manufacturing method of the liquid crystal display device of description. 14. The method of manufacturing a liquid crystal display device according to claim 13, further comprising a step of separating the pixel electrode from the thin film transistor or the scanning line. The liquid crystal display according to claim 10 or 11, further comprising a step of forming a connection pattern for connecting repair electrodes on both sides of a broken line on a signal line or a scanning line after the formation of the repair electrode. Device manufacturing method. 16. The method of manufacturing a liquid crystal display device according to claim 15, wherein the connection pattern for connecting the repair electrodes on the scanning line is formed so as not to overlap the source electrode. The method for manufacturing a liquid crystal display device according to claim 12, wherein the connection pattern is formed by a laser CVD method or an ink jet method.

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