JP2010102237A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a specific layer structure in which the number of manufacturing steps is not increased and the width of the simple lighting test circuit is small, in a display device including a simple lighting test circuit. <P>SOLUTION: The simple lighting test circuit 70 on the side of an image signal line 2 includes common lines 74 for simple lighting testing, which are connected in common to each of the input side lines 63 of a thin film transistor 73 for simple lighting testing, corresponding to a video signal line 2 for each primary color. At least one of the common lines 74 for simple lighting testing is formed of layers constituting a pixel electrode 4, or a part of the layers, is directly connected to the input side line 63 via a contact hole 78 provided to a protective insulating film 8 on the input side line 63. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device, and in particular, is a specific example of a simple lighting inspection circuit provided for performing a simple lighting inspection of product quality before mounting a drive circuit element (driver chip) on a display panel of the display device. This relates to a layer structure.

  In recent years, display devices have been used as information display means for observers in various devices. The main part of the present typical display device (the part having the display area excluding the external circuit and the housing) is replaced with a liquid crystal, plasma, and electroluminescence (EL) instead of the conventional mainstream CRT. ), New display panels using FED (Field Emission Display) and the like have become mainstream. In these new display panels, a plurality of pixels, which are basic units for forming an image, are arranged in a matrix form in the display area. In general, the display area is a flat surface. In addition, the display device can be made thin. These new display devices are also collectively referred to as flat panel displays.

  Taking the liquid crystal display device, which is the most representative display device as an example, from the viewpoint of yield in the manufacturing process, the array substrate on which scanning wiring, video signal wiring, thin film transistors, pixel electrodes, and the like are formed is opposed to this. The yield of the liquid crystal panel in which the liquid crystal is injected into the gap after the counter substrate to be bonded with a gap of about several μm is particularly important. It is desirable to judge the quality as early as possible. In particular, it is effective to inspect before mounting an expensive drive circuit element.

  Generally, an inspection signal is input by applying an inspection needle to each signal terminal of the liquid crystal panel before the drive circuit element is mounted, an image is actually displayed in the display area, and scanning wiring or video signal wiring is performed by visual inspection or the like. A lighting inspection is performed to determine whether there is a short circuit, disconnection, pixel defect, display unevenness, foreign matter, or the like.

  However, as a lighting inspection, in the method of inspecting by individually applying inspection needles to all signal terminals, the number of inspection needles is about the number of scanning wirings and the number of video signal wirings, and it becomes a very large number, The cost of the inspection needle is very high. In particular, in small panels for mobile phones and the like, the demand for cost reduction is severe, so the inspection cost is severely restricted. In small panels for cellular phones, the pitch and size of the signal terminals are gradually decreasing due to the narrowing of the pixel pitch due to the high definition of the display area, and the inspection needles are aligned once for all the signal terminals. Therefore, it is difficult to accurately guess.

  As a method for solving the above-described problems, for example, Patent Document 1 discloses a display device in which a simple lighting inspection circuit is formed on an array substrate. In Patent Document 1, a common wiring for simple lighting inspection is provided in units of red, green, and blue (RGB: Red, Green, Blue) of video signal wiring (drain line), and scanning wiring (gate line) and video signal wiring are They are connected via a simple lighting inspection thin film transistor (inspection transistor). Before mounting the driving circuit element (semiconductor chip), the thin film transistor for simple lighting inspection is turned on, and the inspection signal is connected to the common wiring for simple lighting inspection in RGB color units. It can be supplied from the inspection terminal) to perform simple lighting inspection. In such simple lighting inspection, only a simple solid screen can be displayed, so detailed lighting inspection is difficult, but scanning wiring, video signal wiring short circuit, disconnection, pixel defect, display unevenness, or foreign matter Etc. can be found. As a result, it is possible to make a rough quality determination before mounting the drive circuit element.

  In the product stage, when the simple lighting inspection circuit is cut off and removed, or when the simple lighting inspection circuit is left in the liquid crystal display device, in order to prevent interference of electrical signals between the scanning lines and between the video signal lines, The thin film transistor for simple lighting inspection needs to be turned off.

  In Patent Document 1, since the superimposing inspection circuit including the inspection terminal of the simple lighting inspection circuit is superimposed on the region immediately below the drive circuit element, the increase in the area of the frame region by the simple lighting inspection circuit can be reduced. Yes.

Japanese Patent Laid-Open No. 2004-101863 (FIGS. 1, 3, and 4)

  In recent years, the most typical amorphous Si thin film transistor type liquid crystal display device manufacturing process is a transmissive type or a reflective type five mask manufacturing method (five photolithography processes), or a thin film transistor forming process is a halftone mask. In addition, a four-mask manufacturing method (four times of photoengraving process) using a gray tone mask has become mainstream. In these few mask manufacturing methods, it is difficult to directly connect the same layer as the scanning wiring and the same layer as the video signal wiring, and it is composed of another conductive layer (for example, the same layer as the uppermost pixel electrode). It was necessary to connect via conversion wiring. When conversion wiring is not used, a photoengraving process is required in which a contact hole is made in the gate insulating film between the same layer as the scanning wiring and the same layer as the video signal wiring, and a mask for direct connection is added. Yes, the manufacturing process increased.

  In addition, in the semi-transmission type that is adopted for outdoor use in small and medium-sized models, it is necessary to form two types of pixel electrodes, a transmissive region made of a transparent conductive film and a reflective region made of a highly reflective film. In addition, the number of manufacturing steps of the pixel electrode is increased by one. The direct connection between the same layer as the scanning wiring and the same layer as the video signal wiring is basically the same as the transmission type and the reflection type, and it is necessary to connect via a conversion wiring made of another conductive layer. there were.

  For this reason, in the simple lighting inspection circuit, the common wiring for simple lighting inspection is formed in the same layer as the scanning wiring, and the input for supplying the inspection signal to the thin lighting inspection thin film transistor connected to each scanning wiring and each video signal wiring When the side wiring is formed in the same layer as the video signal wiring in the same manner as the thin film transistor of the pixel, the input side wiring and the common wiring for simple lighting inspection are connected with other conductive layers as described above. It was necessary to connect via conversion wiring.

  In order to connect the input side wiring and the simple lighting inspection common wiring through the conversion wiring, basically, it is necessary to open two contact holes having different depths in the insulating film. That is, a protective insulating film is provided on the video signal wiring, and a gate insulating film and a protective insulating film are provided on the scanning wiring. In an amorphous Si inverted staggered thin film transistor type liquid crystal display device used in a four-mask or five-mask manufacturing method, the insulating film on the scanning wiring has a thickness equivalent to that of the gate insulating film on the video signal wiring. Thicker than the insulation film. As described above, since the conversion wiring is connected via the two contact holes, it is necessary to make the area larger than the total area of the two contact holes. Therefore, there is a problem that the area of the simple lighting inspection circuit is increased by the conversion wiring.

  Alternatively, the simple lighting inspection common wiring is formed in the same layer as the video signal wiring, and the input wiring for supplying the inspection signal to the thin lighting inspection thin film transistor connected to each scanning wiring and each video signal wiring is connected to the pixel. When formed in the same layer as the video signal wiring as in the thin film transistor, there are multiple intersections between the common wiring for simple lighting inspection and the input side wiring made of the same layer, so a short circuit occurs in the case of different inspection signals. It is impossible to construct. At the intersection, as described above, it is necessary to connect via a conversion wiring made of another conductive layer.

  Further, in recent years, the width of the drive circuit element has been narrowed, and it has become increasingly difficult to arrange the entire simple lighting inspection circuit including the inspection terminal in the region immediately below. Alternatively, when a part of the simple lighting inspection circuit is arranged in an area different from the mounting area of the drive circuit element, there is a problem that the frame width is widened by the area of the simple lighting inspection circuit.

  In the display device disclosed in Patent Document 1, since the common wiring for simple lighting inspection and the inspection terminal are arranged in parallel in the frame width direction, it is difficult to cope with the recent narrowing of drive circuit elements. ing. In addition, although an equivalent circuit of the simple lighting inspection circuit is shown, details of a specific layer configuration of the simple lighting inspection circuit that is easily narrowed are unknown.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a display device having a narrow frame width and having a simple lighting inspection circuit without increasing the number of manufacturing steps. And it aims at providing the specific layer structure which can make the area (width) of a simple lighting test circuit small.

  A display device according to the present invention includes a pixel having a thin film transistor and a pixel electrode each having a region surrounded by a plurality of scanning wirings and a plurality of video signal wirings crossing the scanning wirings on an insulating substrate, and the pixels are arranged in a matrix. And a simple lighting inspection circuit in a frame area on the insulating substrate outside the display area. The simple lighting inspection circuit is connected to each of the scanning wiring and the video signal wiring. Each of the plurality of scanning wirings and video signal wirings has a simple lighting inspection common wiring that is commonly connected in a predetermined group via the inspection thin film transistor, and at least one of the simple lighting inspection common wirings The book has a layer constituting a pixel electrode disposed above the video signal wiring via an insulating film, or a part of the layer, and is provided on the scanning wiring or video signal wiring. It is directly connected via an input side wiring for supplying an inspection signal via a simple lighting inspection thin film transistor and a contact hole provided in an insulating film on the input side wiring.

  According to the present invention, the area (width) of the simple lighting inspection circuit can be reduced, and a display device with a small frame width having the simple lighting inspection circuit can be obtained.

  Hereinafter, embodiments of the display device of the present invention will be described with reference to the drawings. Note that, in the drawings for explaining the following embodiments, the same reference numerals indicate the same or corresponding parts, and therefore redundant description is omitted in principle.

Embodiment 1 FIG.
FIG. 1 is a plan view showing a schematic configuration of a display device according to Embodiment 1 of the present invention. FIG. 2 is an enlarged plan view of a part of the simple lighting inspection circuit on the video signal wiring side shown in FIG. 3 is a cross-sectional view taken along line AA in FIG. FIG. 4 is an enlarged plan view of a part of the simple lighting inspection circuit on the scanning wiring side shown in FIG. 5 is a cross-sectional view taken along the line BB in FIG. Note that FIG. 1 shows a schematic configuration of the display device in an equivalent circuit. 2 to 5 describe specific layer configurations.

  The first embodiment is a case where the display device is a transmissive liquid crystal display device 100. Further, it is assumed that it is formed by the most common method of manufacturing an amorphous Si thin film transistor type five-mask. In FIG. 1, a liquid crystal display device 100 includes an array substrate 50 having a display region 40 in which a plurality of pixels 10 are arranged in a matrix, and a counter substrate (color filter substrate) 55 opposite to the array substrate 50. The liquid crystal panel is arranged with a gap of about 2 to 5 μm (not shown) and liquid crystal is injected into the gap, and an external circuit (not shown) including a power source, an image processing circuit, and the like. In the transmissive liquid crystal display device 100, a backlight (not shown) is disposed on the back surface of the liquid crystal panel.

  In the transmissive liquid crystal display device 100, the display area 40 on the array substrate 50 is an area surrounded by a plurality of scanning wirings (gate wirings) 1 and a plurality of video signal wirings (source wirings) 2 intersecting therewith. Pixels 10 each including a thin film transistor 3 that is a switch element made of a semiconductor film, a pixel electrode 4 made of a transparent conductive film such as ITO (Indium Tin Oxide), and the like are arranged in a matrix. The array substrate 50 includes the display area 40 and the outer frame area 45. The scanning wiring 1 and the video signal wiring 2 are formed of a metal film made of a metal such as Al, Cu, Mo, Ta, Ti, Cr, W, or an alloy thereof or a laminated film.

  The matrix substrate 50 and the counter substrate 55 are each attached with a polarizing plate or the like (not shown) on the outside. On the liquid crystal side (inner side) of the counter substrate 55, color filters of three primary colors of red, green and blue (RGB) are provided in a vertical stripe shape. Further, ITO or the like is formed on the entire surface of the counter substrate 55 on the color filter (liquid crystal side). A counter electrode 5 made of a transparent conductive film is provided.

  Note that the color filter is not limited to the three primary colors of RGB, but may be other primary color configurations or four or more primary colors, and the color filter is not necessary for monochrome display.

  Further, in the case where the liquid crystal driving of the liquid crystal display device 100 is a lateral electric field (IPS: In Plane Switching) method substantially parallel to the surface of the array substrate 50, the counter electrode 5 is formed on the array substrate 50, so that the counter substrate 55 side May not have the counter electrode 5.

  In FIG. 1, for the sake of convenience, the pixel 10 is described as a square in each primary color. However, in the actual liquid crystal display device 100, in the case of color display, three pixels 10 of the three primary colors RGB are combined to form a square. In many cases, the combination of these three primary colors is called a pixel, and the minimum unit of each primary color is called a sub-pixel. In this specification, the minimum unit of each primary color is a pixel 10.

  Further, as a predetermined group, the plurality of scanning lines 1 are distinguished by odd-numbered scanning lines 1m and even-numbered lines by scanning lines 1n. The plurality of video signal wirings 2 are distinguished by video signal wirings 2r, 2g, and 2b corresponding to the three primary colors RGB of the color filter. Also, in the explanation of each member below, m, n are added to the code corresponding to the odd number and even number, and r, g, b are added to the code corresponding to the three primary colors RGB as necessary. The group is described separately.

  In the frame area 45, not only a plurality of scanning wirings 1 and video signal wiring 2 lead lines, but also a mounting area of the drive circuit element 60, a simple lighting inspection circuit 70 area, and a plurality of external connection terminals 90 connected to an external circuit. Are provided. Although not shown, a storage capacitor electrode provided for holding a liquid crystal voltage in each pixel 10 is provided on the array substrate 50, and a storage capacitor common to which the storage capacitor electrode is commonly connected to the frame region 45. Connection pads (excluding the IPS method) for electrical connection with the wiring and the counter electrode 5 on the counter substrate 45 are provided.

  In the first embodiment, the drive circuit element 60, the simple lighting inspection circuit 70 on the video signal wiring 2 side, the external connection terminal 90, and the like are arranged in the frame region 45 on the lower side of the array substrate 50, and the other The frame width on the three sides is smaller than this. Such a configuration is often used in the small liquid crystal display device 100.

  The drive circuit element 60 is directly mounted on the array substrate 50 by COG (Chip On Glass). The COG mounting is performed by using bump-like output and input bump electrodes (not shown) provided on the mounting surface side of the drive circuit element 60 made of a semiconductor chip (Si element), and the bump electrodes on the array substrate 50. The output-side terminal 62 and the input-side terminal 64 provided at positions corresponding to the above are directly electrically connected via an anisotropic conductive film (ACF: Anisotropic Conductive Film). COG mounting is often used in medium- and small-sized liquid crystal display devices 100, and uses a resin film mounted with a drive circuit element 60, such as TAB (Tape Automated Bonding) mounting that is often used in large-sized display devices. Therefore, since the drive circuit element 60 is mounted directly on the array substrate 50, there are advantages in that it is excellent in impact resistance and has few disconnections after mounting. Moreover, since the process of mounting the Si chip on the resin film member or the resin film is not required, the cost can be reduced as compared with the TAB mounting.

  In addition, as shown in FIG. 1, when the drive circuit element 60 is COG-mounted only in the frame region 45 on one side, for the scanning wiring 1 for reducing the mounting area of the drive circuit element 60 and reducing the cost. A drive circuit element 60 in which a drive circuit for the video signal wiring 2 is integrated is often used. Here, the left side of the drive circuit element 60 corresponds to the drive circuit for the scanning wiring 1 and the right side substantially corresponds to the drive circuit for the video signal wiring 2. Of course, the drive circuit elements 60 for the scanning wiring 1 and the video signal wiring 2 may have different configurations.

  Further, in order to reduce the frame width on the COG mounting area side, the width of the drive circuit element 60 is gradually reduced, and those having a width of 1 mm or less have appeared. Further, by reducing the width of the drive circuit element 60, the number of drive circuit elements 60 that can be taken from one Si substrate is increased, so that the cost of the drive circuit element 60 can be reduced at the same time.

  However, when the width of the drive circuit element 60 is gradually reduced, it overlaps with the area immediately below the drive circuit element 60 and overlaps with the area between the output side terminal 62 and the input side terminal 64 on the array substrate 50 as in the prior art. Therefore, it is gradually difficult to arrange the entire simple lighting inspection circuit 70. In FIG. 1, the main part of the simple lighting inspection circuit 70 on the video signal wiring 2 side is arranged in a region immediately below the drive circuit element 60, but the inspection terminals 81, 82, 85, 86 are connected to the drive circuit element 60. It is placed outside the mounting area. Here, it is arranged in the frame region 45 on the right side of the drive circuit element 60. The inspection terminals 81, 82, 85, and 86 have a larger area than the output side terminal 62 and the input side terminal 64 so that it is not necessary to strictly align the inspection terminals for the simple lighting inspection.

  The simple lighting inspection common gate wiring 71 of the simple lighting inspection thin film transistor 73 (73r, 73g, 73b) on the video signal wiring 2 side is connected to the inspection terminal 85. The simple lighting inspection common wirings 74 (74r, 74g, 74b) connected in common to the simple lighting inspection thin film transistors 73 (73r, 73g, 73b) corresponding to the respective primary colors are respectively inspected terminals 86 (86r, 86g, 86b). )It is connected to the.

  On the other hand, the simple lighting inspection circuit 70 on the scanning wiring 1 side is arranged in the frame area 45 on the right side of the display area 40. Corresponding to the scanning wiring 1 (1m, 1n), the simple lighting inspection common gate wiring 11 (11m, 11n) of the thin film transistor 72 (72m, 72n) for simple lighting inspection is connected to the inspection terminal 81 (81m, 81n). Has been. The simple lighting inspection common wiring 12 for the input signal of the simple lighting inspection thin film transistor 72 (72m, 72n) is connected to the same inspection terminal 82. In this way, even if a signal for turning on the thin film transistor 3 of the pixel 10 is input to the simple lighting inspection common wiring 12, the odd number 1m of the scanning wiring 1 is set by the simple lighting inspection common gate wiring 11 (11m, 11n). In correspondence with the even number 1n, the simple lighting inspection thin film transistors 72m and 72n can be turned on and off separately, so that the scanning wirings 1m and 1n can be turned on and off separately. Thereby, it is possible to inspect a short circuit between the adjacent scanning wirings 1m and 1n.

  The inspection terminals 81, 82, 85, and 86 may be as small as the input terminal 62 and the output terminal 64 if the positioning of the inspection needle for the simple lighting inspection can be strictly performed. If there is a margin in the area immediately below, the inspection terminals 81, 82, 85, 86 are also directly below the drive circuit element 60 in the extending direction of the simple lighting inspection common gate wiring 71 and the simple lighting inspection common wiring 74. They can also be placed side by side.

  Next, the operation and effect of the layer configuration of the simple lighting inspection circuit 70 which is the main part of the present invention will be described in detail on the video signal wiring 2 side with reference to FIGS. The scanning wiring 1 side will be described in detail with reference to FIGS.

  First, the layer configuration of the simple lighting inspection circuit 70 on the video signal wiring 2 side will be described in detail. As shown in FIGS. 2 and 3, the output-side terminal 62 that is COG-connected to the output-side bump electrode of the drive circuit element 60 is not only connected to the video signal wiring 2 but also a corresponding simple lighting inspection thin film transistor. 73 to the output side wiring 61. The simple lighting inspection thin film transistor 73 is formed simultaneously with the thin film transistor 3 of the pixel 10. A gate insulating film 7 and a semiconductor film 6 are formed above the common gate wiring 71 for simple lighting inspection. Here, the semiconductor film 6 constituting the thin film transistor 3 and the simple lighting inspection thin film transistor 73 is patterned in an island shape. The simple lighting inspection common wiring 74 is connected to the input side wiring 63 of the simple lighting inspection thin film transistor 73 in common for each primary color. Here, a simple lighting inspection thin film transistor 73 (73r, 73g, 73b) is provided corresponding to the RGB three-color video signal wirings 2 (2r, 2g, 2b), and a simple lighting inspection corresponding to each primary color is provided. The common wiring 74 (74r, 74g, 74b) is connected in common. The simple lighting inspection common gate wiring 71 serving as the common gate electrode of the simple lighting inspection thin film transistors 73 (73 r, 73 g, 73 b) is formed in the same layer as the scanning wiring 1.

  Further, the surface of the output side terminal 62 is formed of a transparent oxide conductive film in the same layer as the pixel electrode 4, and a metal film below the output side terminal 62 is connected through a contact hole 68 provided in the protective insulating film 8. And connected directly. The metal film under the output side terminal 62 is formed in the same layer in which the video signal wiring 2 extends. Further, the metal film under the output side terminal 62 further extends to serve as the output side wiring 61 of the simple lighting inspection thin film transistor 73. The input-side wiring 63 of the simple lighting inspection thin film transistor 73 is also formed in the same layer as the video signal wiring 2.

  In general, an oxide conductive film made of ITO or the like is more excellent in connection resistance stability and corrosion resistance than the metal film on the terminal surface, and is excellent in terminal reliability. Therefore, in the first embodiment, not only the output side terminal 62 but also various terminals such as the input side terminal 64, the external connection terminal 90, the inspection terminals 81, 82, 85 and 86 formed on the array substrate 50. The surface is formed of an oxide conductive film such as ITO in the same layer as the pixel electrode 4.

  Here, the input-side wiring 63 of the simple lighting inspection thin film transistor 73 on the video signal wiring 2 side is commonly connected to the simple lighting inspection common wirings 74r, 74g, and 74b corresponding to the respective RGB primary colors. The outermost simple lighting inspection common wiring 74b (here, B is the primary color, but this primary color may be any of RGB) near the end of 50 is the input side wiring of the thin lighting inspection thin film transistor 73b. Reference numeral 63 denotes a T-shaped extension in which the primary color input side wirings 63 of B are connected to each other, and is formed in the same layer as the video signal wiring 2. Further, the common lighting 74r and 74g for the simple lighting inspection inside the other primary colors are formed from an oxide conductive film made of the same layer as the pixel electrode 4 or at least a part of the layers constituting the laminated structure. The input side wiring 63 is directly connected to the input side wiring 63 through a contact hole 78 provided in the protective insulating film 8 on the input side wiring 63.

  That is, since the simple lighting inspection common wiring 74 is not formed in the same layer as the scanning wiring 1, the most common five-mask process is used to connect the video signal wiring 2 and the input side wiring 63 formed in the same layer. Alternatively, even in the manufacturing method of a four-mask process using a gray tone (halftone) mask, it is not necessary to connect via a conversion wiring. Further, the outermost simple lighting inspection common wiring 74b near the end of the array substrate 50 is formed of the same layer in which the input-side wiring 63 extends, and therefore does not require a contact hole. Therefore, in the simple lighting inspection circuit 70 on the video signal wiring 2 side, since there is no conversion wiring composed of the pixel electrode 4 in the connection between all the input side wirings 63 and the simple lighting inspection common wiring 74, the conversion wiring is used. An area to be provided is not necessary. Further, the width of the simple lighting inspection circuit 70 on the video signal wiring 2 side can be reduced without increasing the number of manufacturing steps.

  In the transmissive liquid crystal display device 100, the pixel electrode 4 is a transparent conductive film such as ITO, and is an oxide conductive film. On the other hand, the video signal wiring 2 in the same layer as the input side wiring 63 of the thin film transistor 73 for simple lighting inspection is made of a metal such as Al, Cu, Mo, Ta, Ti, Cr, W, or an alloy or a laminated film thereof. Since it consists of a film, the specific resistance is usually smaller than that of an oxide conductive film. Therefore, if the wiring width of the outermost simple lighting inspection common wiring 74b is the same resistance value as the other inner simple lighting inspection common wirings 74r and 74g, it can be made smaller than these wiring widths. Furthermore, the width of the simple lighting inspection circuit 70 can be reduced. Further, since a contact hole for connection with the input side wiring 63 is not required, the reliability is excellent.

  Next, the layer configuration of the simple lighting inspection circuit 70 on the scanning wiring 1 side will be described in detail. As shown in FIG. 4 and FIG. 5, corresponding to the odd-numbered and even-numbered scanning wirings 1m and 1n, there are thin-film transistors 72m and 72n for simple lighting and common gate wirings 11m and 11n. The simple lighting inspection thin film transistors 72m and 72n are formed simultaneously with the thin film transistor 3 of the pixel 10. At present, in the manufacturing method of the most general five-mask process or the four-mask process using a gray tone (halftone) mask, the thin film transistor for simple lighting inspection comprising the same layer as the scanning wiring 1 and the video signal wiring 2 For connection to the output side wiring 13 of 72, the conversion wiring 15 via the two contact holes 16 and 18 is necessary. However, unlike the connection between the input side wiring 63 of the simple lighting inspection circuit 70 on the video signal wiring 2 side and the common wiring 74 for simple lighting inspection, the position where the conversion wiring 15 is provided has few restrictions on arrangement. That is, the conversion wiring 15 can be disposed at a relatively free position as long as it is an area between the scanning wiring 1 outside the display area 40 and the simple lighting inspection circuit 70 on the scanning wiring 1 side. For example, it can be disposed in a seal portion around the display region 40 that seals the liquid crystal or a region such as a surrounding light shielding film. For this reason, in the simple lighting inspection circuit 70 on the scanning wiring 1 side, the conversion wiring 15 hardly affects the increase in the frame width on the right side of the display area 40. Further, in the first embodiment, the main part of the simple lighting inspection circuit 70 on the scanning wiring 1 side is not on the mounting area side of the drive circuit element 60, and therefore, the advantage that the width of the drive circuit element 60 is not limited. There is.

  The input side wiring 14 and the simple lighting inspection common wiring 12 are the same as the outermost simple lighting inspection common wiring 74b of the simple lighting inspection circuit 70 on the video signal wiring 2 side, which is close to the end of the array substrate 50. Similar layers can be formed. That is, the simple lighting inspection common wiring 12 can be configured in the same layer as the video signal wiring 2. Therefore, neither a conversion wiring nor a contact hole is required for connection between the input side wiring 14 and the simple lighting inspection common wiring 12. Further, since the simple lighting inspection common wiring 12 is made of the same layer as the video signal wiring 2, the specific resistance is small, and the wiring width of the simple lighting inspection common wiring 12 is smaller than that of the pixel electrode 4 and the same layer. it can.

  As described above, in the first embodiment, the simple lighting inspection circuit 70 on the scanning wiring 1 side includes the three wirings of the common lighting wirings 11m and 11n for the simple lighting inspection and the common wiring 12 for the simple lighting inspection, and the conversion. Since it is necessary to provide the wiring 15, the frame width on the right side of the display area 40 is slightly increased. However, it is much smaller than the frame width on the lower side of the display area 40 where the COG mounting area and the external connection terminal 90 are provided, and the left side of the display area 40 where a large number of lead lines for the scanning lines 1 are arranged. The frame width on the right side of the display area 40 is smaller than the frame width of the display area 40. Therefore, the increase in the frame width by the simple lighting inspection circuit 70 on the scanning wiring 1 side hardly causes a problem.

Embodiment 2. FIG.
FIG. 6 is an enlarged plan view of a part of the simple lighting inspection circuit on the video signal wiring side of the liquid crystal display device according to the second embodiment of the present invention. 7 is a cross-sectional view taken along the line CC in FIG. FIG. 8 is an enlarged plan view of a part of the simple lighting inspection circuit on the scanning wiring side of the liquid crystal display device according to the second embodiment of the present invention. 9 is a cross-sectional view taken along the line DD in FIG.

  In the second embodiment, the liquid crystal display device 100 is not a transmissive type but a reflective type or a transflective type. The schematic configuration of the liquid crystal display device 100 is the same as that in FIG. The difference from Embodiment 1 is that in the reflective liquid crystal display device 100, the pixel electrode 4 is not an oxide conductive film, but a highly reflective metal such as Al or Ag, or a single layer film of these alloys, Or in addition to this, it is a point comprised with the electrically conductive film which consists of laminated films with ITO, Mo, Ta, Ti, Cr, W, etc. Since Al, Ag, or an alloy thereof has a small specific resistance, the layer constituting the pixel electrode 4 can have a small specific resistance equal to or less than that of the scanning wiring 1 and the video signal wiring 2.

  Further, in the transflective liquid crystal display device 100, the transmission region of the pixel electrode 4 is formed of the same transparent oxide conductive film as that of the transmission type, and the reflection region of the pixel electrode 4 is the same conductive film as that of the reflection type described above. Consists of. Thus, in the case of the reflective or transflective liquid crystal display device 100, as shown in FIGS. 6 and 7, the simple lighting inspection common wiring 74 (74r, 74g, 74b) on the video signal wiring 2 side is provided. These are formed of all or a part of the conductive film constituting the pixel electrode 4 and are directly connected through a contact hole 28 formed on the protective insulating film 8 on the input side wiring 63. .

  For example, in the transflective liquid crystal display device 100, the simple lighting inspection common wirings 74r and 74g are made of metal such as Al and Ag used in the reflective region, or a single layer film of these alloys, or in addition to this. Therefore, the specific resistance is smaller than that of the oxide conductive film used in the transmissive region because the conductive film is made of a laminated film of ITO, Mo, Ta, Ti, Cr, W or the like. Further, when the common wiring 74 for simple lighting inspection is formed by a laminated structure of the oxide conductive film in the transmission region of the pixel electrode 4 and the conductive film in the reflection region, the specific resistance can be further reduced. Therefore, the widths of the simple lighting inspection common wirings 74r and 74g can be reduced as compared with the first embodiment formed of the oxide conductive film. Therefore, the width of the simple lighting inspection circuit 70 can be further reduced.

  In the second embodiment, the outermost simple lighting inspection common wiring 74b near the end of the array substrate 50 is also formed of the same conductive film as the simple lighting inspection common wirings 74r and 74g. In the case of the reflective or transflective liquid crystal display device 100, the specific resistance of the simple lighting inspection common wiring 74b is equal to or less than that of the scanning wiring 1 and the video signal wiring 2 as described above. This is because it can.

  Of course, the outermost simple lighting inspection common wiring 74b may be formed in the same layer as the input-side wiring 63 that does not require the contact hole 28, as in the first embodiment.

  In the case of the transflective liquid crystal display device 100, the simple lighting inspection common wiring 74 may have a stacked structure of a metal film in the reflective region of the pixel electrode 4 and an oxide conductive film in the transmissive region. When the surface of the common wiring 74 for simple lighting inspection is a laminated structure in which an oxide conductive film is formed, various terminals such as the output side terminal 62, the input side terminal 64, the external connection terminal 90, the inspection terminals 81, 82, 85, 86, etc. Since the surface of the film becomes an oxide conductive film as it is, no additional manufacturing process is required. Moreover, the corrosion resistance of the common wiring 74 for simple lighting inspection is also improved.

  When the surface of the common wiring 74 for simple lighting inspection is not an oxide conductive film and the laminated film is a conductive film on the lower layer side, the surface of each terminal has the same layer of oxide conductive as the transmission region of the pixel electrode 4. It should be a film. For example, in the inspection terminal 86, the upper metal film of the laminated film constituting the simple lighting inspection common wiring 74 may be removed so that the oxide conductive film is exposed.

  Next, the inspection circuit 70 on the scanning wiring 1 side will be described in detail. The simple lighting inspection circuit 70 on the scanning wiring 1 side is provided in the right frame region 45 as in the first embodiment. 8 and 9, the simple lighting inspection common wiring 12 is different from the first embodiment in that the pixel electrode is similar to the simple lighting inspection common wiring 74 on the video signal wiring 2 side in the second embodiment. 4 is a metal film in the reflective region, or in addition, a laminated film with an oxide conductive film in the transmissive region. Then, it is directly connected to the input side wiring 14 through a contact hole 19 provided in the protective insulating film 8 on the input side wiring 14. The simple lighting inspection common wiring 12 is connected to the inspection terminal 82.

  As described above, in the reflective or transflective liquid crystal display device 100, if the common wirings 12 and 74 for simple lighting inspection are formed of all or a part of the conductive film constituting the pixel electrode 4, Since the specific resistance is small, the wiring width can be reduced, and the width of the simple lighting inspection circuit 70 can be further reduced as compared with the transmission type.

Embodiment 3 FIG.
FIG. 10 is a plan view showing a schematic configuration of the liquid crystal display device according to Embodiment 3 of the present invention. In the first and second embodiments, the main part of the simple lighting inspection circuit 70 on the scanning wiring 1 side is arranged in the frame region 45 on the right side of the pixel region 40. However, in the third embodiment, the simple portion on the scanning wiring 1 side is simplified. The main part of the lighting inspection circuit 70 is also arranged so as to overlap with a region immediately below the drive circuit element 60. In the third embodiment, the simple lighting inspection thin film transistor 72 for the scanning wiring 1 is not divided into even numbers and odd numbers. Further, the common gate wiring 75 for simple lighting inspection of the thin film transistors 72 and 73 for simple lighting inspection for the scanning wiring 1 and the video signal wiring 2 is made one in common. Therefore, compared with the first and second embodiments, the simple lighting inspection common gate wirings 11m and 11n on the scanning wiring 1 side and the inspection terminals 81m and 81n connected thereto are unnecessary, and the simple lighting inspection common wiring is eliminated. The number 2 and the number of inspection terminals 2 can be reduced.

  In the third embodiment, the inspection terminal 87 connected to the simple lighting inspection common gate wiring 75 for the scanning wiring 1 and the video signal wiring 2 and the inspection terminal 86 connected to the simple lighting inspection common wiring 74 are driven. It is arranged on the right side of the circuit element 60. The inspection terminal 82 connected to the common lighting inspection common wiring 12 on the scanning wiring 1 side is disposed on the left side of the drive circuit element 60. Of course, if there is a margin in the area of the drive circuit element 60, these inspection ends 82, 86, 87 may be arranged in the area immediately below the drive circuit element 60.

  Alternatively, if the inspection terminal 82 has a margin in the area of the drive circuit element 60, it is preferable to extend the common wiring 12 for simple lighting inspection to the right side and combine them on the same side as the other inspection terminals 86 and 87. This is desirable from the viewpoint of configuring the inspection needle.

  In actual use other than the simple lighting inspection, the gate OFF potential is supplied to the inspection terminal 87 so that the simple lighting inspection thin film transistors 72 and 73 are turned off.

  In this way, most of the simple lighting inspection circuits 70 on the scanning wiring 1 side and the video signal wiring 2 side are arranged so as to be superimposed on the region immediately below the drive circuit element 60, thereby comparing with the first and second embodiments. Thus, the frame width on the right side of the display area 40 can be reduced. Further, it is possible to eliminate an increase in the width of the lower frame where the drive circuit element 60 is located.

  As described above, in the first to third embodiments, the simple lighting inspection common wiring 74 on the video signal wiring 2 side includes the three simple lighting inspection common wirings 74r, 74g, and 74b corresponding to the three primary colors of RGB. For example, the simple lighting inspection common wiring 74 on the video signal wiring 2 side may have a group configuration of six by distinguishing odd numbers and even numbers for each primary color. Thus, if the number of the simple lighting inspection common wirings 12 and 74 on the scanning wiring 1 side and the video signal wiring 2 side is increased, the width of the simple lighting inspection circuit 70 increases and the number of inspection terminals also increases. In the layer configuration of the present invention, an increase in a small width can be suppressed. And since a more complicated test | inspection image can be displayed now, there exists an advantage which can perform a more detailed simple lighting test | inspection.

  The display device 100 is not limited to a liquid crystal display device, and may be a self-luminous EL, FED, or a reflective electronic paper using fine particles or oil droplets as long as the display device has a simple lighting inspection circuit 70. It can also be applied to. In the case of the self-luminous display device 100 and the reflective display device 100, the backlight is not necessary.

It is a top view which shows schematic structure of the display apparatus in Embodiment 1 of this invention. FIG. 3 is an enlarged plan view of a part of a simple lighting inspection circuit on the video signal wiring side of the display device according to the first embodiment of the present invention. It is sectional drawing which shows the AA cross section of FIG. It is the top view to which a part of simple lighting test circuit by the side of a scanning wiring of a display in Embodiment 1 of the present invention was expanded. It is sectional drawing which shows the BB cross section of FIG. It is the top view to which a part of simple lighting test circuit by the side of an image signal wiring of a display in Embodiment 2 of the present invention was expanded. It is sectional drawing which shows CC cross section of FIG. It is the top view to which a part of simple lighting test circuit by the side of a scanning wiring of a display in Embodiment 2 of the present invention was expanded. It is sectional drawing which shows the DD cross section of FIG. It is a top view which shows schematic structure of the display apparatus in Embodiment 3 of this invention.

Explanation of symbols

1, 1m, 1n Scanning wiring 2, 2r, 2g, 2b Video signal wiring 3 Thin film transistor 4 Pixel electrode 5 Counter electrode 6 Semiconductor film 7 Gate insulating film 8 Protective insulating film 10 Pixel 11, 11m, 11n Common gate wiring for simple lighting inspection 12 Common wiring for simple lighting inspection 13 Output side wiring 14 Input side wiring 15 Conversion wiring 16, 18, 19 Contact hole 28 Contact hole 40 Display area 45 Frame area 50 Array substrate 55 Counter substrate 60 Drive circuit element 61 Output side wiring 62 Output Side terminal 63 Input side wiring 64 Input side terminals 66, 68 Contact hole 70 Simple lighting inspection circuit 71 Simple lighting inspection common gate wiring 72, 72m, 72n Simple lighting inspection thin film transistor 73, 73r, 73g, 73b Simple lighting inspection thin film transistor 74, 74r, 74g, 74b For lighting inspection for the common wiring 75 simple lighting test common gate line 78 contact hole 81,82,85,86,87 inspection terminals 90 external connection terminal 100 liquid crystal display device

Claims (5)

On the insulating substrate, a plurality of scanning wirings, a plurality of video signal wirings crossing the scanning wirings,
A pixel having a region surrounded by the scanning wiring and the video signal wiring, and having a thin film transistor and a pixel electrode;
A display area in which the pixels are arranged in a matrix, and
With a simple lighting inspection circuit in the frame area on the insulating substrate outside the display area,
The simple lighting inspection circuit is commonly used in a predetermined group for each of the plurality of scanning wirings and the video signal wirings through the simple lighting inspection thin film transistors connected to the scanning wirings and the video signal wirings. It has common wiring for simple lighting inspection to connect,
At least one common wiring for this simple lighting inspection
While having a layer constituting the pixel electrode disposed above the video signal wiring via an insulating film, or a part of the layer,
An input side wiring for supplying an inspection signal to the scanning wiring or the video signal wiring through the thin film transistor for simple lighting inspection, and a contact hole provided in the insulating film on the input side wiring are directly connected. A display device. The display device according to claim 1, wherein the outermost common lead-out wiring for simple lighting inspection that is close to an end portion of the insulating substrate is the same layer extending the input-side wiring. 2. The common lighting wiring for simple lighting inspection other than the outermost side close to an end of the insulating substrate has a layer constituting the pixel electrode or a part of the layer. 2. The display device according to 2. The display according to any one of claims 1 to 3, wherein at least a part of the simple lighting inspection circuit is arranged so as to overlap directly below a drive circuit element mounted directly on the insulating substrate. apparatus. The display device according to claim 1, wherein at least one of the simple lighting inspection common wires has an oxide conductive film on a surface.

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