JP2018028575A - Display device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce resistance of common electrodes without sacrificing flatness of a display area.SOLUTION: A display device comprises; thin film transistors provided on a substrate; a resin layer provided on top of the thin film transistors; grooves formed on the resin layer; a first conductive layer filling the grooves; and a second conductive layer provided on the resin layer to be superimposed on and in contact with the first conductive layer, the second conductive layer being more conductive than the first conductive layer. The first conductive layer may be made of a metal material while the second conductive layer may be made of a metal oxide material.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a display device including a plurality of pixels. In particular, the present invention relates to a display device having a common electrode (common electrode) on an array substrate.

  Conventionally, liquid crystal displays and organic EL displays have been developed as display devices. These display devices include an optical element such as a liquid crystal element or a light emitting element in each of a plurality of pixels constituting a display area, and display an image on a screen by controlling the amount of light output from each pixel. A liquid crystal element or a light emitting element basically has a structure in which an optical material is sandwiched between two electrodes. The amount of light to be output is controlled using a change in the optical material caused by supplying a predetermined potential to the two electrodes.

  By the way, as one of the two electrodes constituting the liquid crystal element or the light emitting element (particularly, the common electrode), an electrode having a light transmitting property (transparent electrode) is often used in general. This is because it is necessary to transmit backlight light or reflected light from the pixel electrode in the case of a liquid crystal element, and to transmit light emitted from an optical material in the case of an organic EL element.

  Such a transparent electrode is usually made of a transparent conductive material such as ITO, and has a characteristic that its resistance value is higher than that of a metal electrode. For this reason, when the area of the transparent electrode is increased, a potential drop may occur due to the wiring resistance, and the potential may vary. Therefore, as a countermeasure against the potential drop of the transparent electrode, a technique is known in which a conductive film having a lower resistance value is electrically connected to reduce the resistance as a whole (Patent Document 1).

JP 11-337945 A

  Here, as a driving method of the liquid crystal display, an IPS (In Plane Switching) method and an FFS (Fringe Field Switching) method are known. In these driving methods, the alignment of the liquid crystal is controlled by a lateral electric field formed between the pixel electrode and the common electrode. Therefore, each of these driving methods has a feature that a common electrode is formed on the array substrate and high flatness is required in the display region.

  When the technique described in Patent Document 1 described above is applied to such a drive-type liquid crystal display, an auxiliary wiring or the like is further laminated on the common electrode provided on the array substrate. Therefore, the unevenness (undulations) on the surface on the array substrate side is increased, and the flatness of the display area may be impaired. In addition, the liquid crystal layer may be disturbed in alignment due to unevenness on the surface on the array substrate side, which may cause a problem of light leakage during image display.

  The present invention solves the above-described problems, and an object thereof is to reduce the resistance of a common electrode without impairing the flatness of a display region.

  A display device according to an embodiment of the present invention includes a thin film transistor on a substrate, a resin layer on the thin film transistor, a groove provided in the resin layer, a first conductive layer embedded in the groove, A second conductive layer provided on the resin layer, a part of which overlaps and is in contact with the first conductive layer, and has a higher conductivity than the first conductive layer.

  Furthermore, the pixel electrode may be provided so as to face the second conductive layer and the insulating layer and connected to the thin film transistor.

  The insulating layer may be disposed between the resin layer and the second conductive layer and may cover the pixel electrode. At this time, the insulating layer may cover the inside of the groove.

  As another form, the insulating layer may be provided so as to cover the second conductive layer. At this time, the second conductive layer has a first opening, and the pixel electrode is connected to the thin film transistor through a second opening provided in the resin layer inside the first opening. May be. Furthermore, the insulating layer may have a third opening inside the first opening.

  The thin film transistor is connected to a gate wiring extending in a row direction and a source wiring extending in a column direction, and the second conductive layer is connected to the first portion extending along the gate wiring or the source wiring, and the first portion And a second portion overlapping with the pixel electrode.

  The first conductive layer may be provided along the first portion of the second conductive layer.

  The second portion in the second conductive layer may include a plurality of portions patterned in a linear shape.

  In one embodiment of the present invention, a method of manufacturing a display device includes forming a thin film transistor on a substrate, forming a resin layer on the thin film transistor, forming a groove in the resin layer, and forming the first inside the groove. Forming a second conductive layer that is embedded with a conductive layer and that partially overlaps and contacts the first conductive layer on the resin layer.

  At the same time as forming the groove in the resin layer, an opening reaching the thin film transistor may be formed in the resin layer. At that time, a halftone mask or a gray tone mask may be used.

  The first conductive layer may be formed by an electrolytic plating method when the inside of the groove is filled with the first conductive layer.

  The second conductive layer may be made of a metal oxide material, and the first conductive layer may be made of a metal material.

It is a top view which shows the structure of the display apparatus in 1st Embodiment. It is sectional drawing which shows the structure of the pixel of the display apparatus in 1st Embodiment. It is a top view which shows the structure of the pixel of the display apparatus in 1st Embodiment. It is sectional drawing which shows the manufacturing method of the display apparatus in 1st Embodiment. It is sectional drawing which shows the manufacturing method of the display apparatus in 1st Embodiment. It is sectional drawing which shows the manufacturing method of the display apparatus in 1st Embodiment. It is sectional drawing which shows the manufacturing method of the display apparatus in 1st Embodiment. It is sectional drawing which shows the manufacturing method of the display apparatus in 1st Embodiment. It is sectional drawing which shows the manufacturing method of the display apparatus in 1st Embodiment. It is a top view which shows the structure of the pixel of the display apparatus in 2nd Embodiment. It is a top view which shows the structure of the pixel of the display apparatus in 3rd Embodiment. It is sectional drawing which shows the structure of the pixel of the display apparatus in 3rd Embodiment. It is sectional drawing which shows the structure of the pixel of the display apparatus in 4th Embodiment. It is a top view which shows the structure of the pixel of the display apparatus in 4th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in various modes without departing from the gist thereof, and is not construed as being limited to the description of the embodiments exemplified below.

  Further, in order to make the explanation clearer, the drawings may be schematically represented with respect to the width, thickness, shape, and the like of each part as compared with the actual embodiment, but are merely examples, and the interpretation of the present invention. It is not intended to limit. In addition, in the present specification and each drawing, elements having the same functions as those described with reference to the previous drawings may be denoted by the same reference numerals and redundant description may be omitted.

  In the present specification, “upper” includes not only the case of being placed directly on a certain object but also the case of being placed with another object in between. The same applies to the term “below”. Further, terms such as “upper” and “lower” indicate a relative vertical relationship between objects, and do not mean an absolute vertical relationship. Specifically, the direction away from the main surface of the substrate is defined as “up” and the approaching direction is defined as “down” with reference to the main surface of the substrate (surface on which elements and the like are formed).

  When a thin film is processed to form a plurality of thin film patterns, the plurality of patterns may have different functions or roles. These plural patterns are derived from thin films formed as the same layer in the same process, and are composed of the same layer structure and the same material. Therefore, in this specification, it is defined that these plural patterns exist in the same layer.

(First embodiment)
<Configuration of display device>
FIG. 1 is a plan view showing the configuration of the display device according to the first embodiment. FIG. 2 is a cross-sectional view illustrating a configuration of a pixel of the display device according to the first embodiment. FIG. 3 is a plan view illustrating a configuration of a pixel of the display device according to the first embodiment. FIG. 2 is a diagram corresponding to a cross section taken along the alternate long and short dash line AA ′ in the plan view shown in FIG. 3.

  In the present embodiment, a liquid crystal display device is illustrated as an example of the display device. Specifically, a liquid crystal display device driven by an FFS method is exemplified. However, the present invention can be applied to a display device other than a liquid crystal display device (for example, an organic EL display device) as long as the display device has a common electrode on the array substrate side.

  First, the overall configuration of the liquid crystal display device 100 according to the first embodiment will be described with reference to FIG. The liquid crystal display device 100 has a display area 104 on a substrate 102. The display area 104 includes a plurality of pixels 106. That is, an area where a plurality of pixels 106 are arranged in the row direction and the column direction functions as the display area 104. Each pixel 106 includes a liquid crystal element as a display element. For example, a multicolor display can be performed by constructing a liquid crystal element and its peripheral structure so that the adjacent pixels 106 give red, green, or blue. The arrangement of the pixels 106 is not limited, and a known arrangement such as a stripe arrangement or a delta arrangement can be employed.

  Further, the liquid crystal display device 100 includes a driving circuit for supplying various signals to the pixel 106. Specifically, as illustrated in FIG. 1, the liquid crystal display device 100 includes gate side driving circuits 108 and 110 and a source side driving circuit 112. Although FIG. 1 shows an example in which two gate side driver circuits 108 and 110 are provided on both sides of the display region 104, the number of gate side driver circuits is not limited to this.

  Further, it is not necessary to install part or all of the gate side driver circuits 108 and 110 and the source side driver circuit 112 on the substrate 102. For example, a driver circuit formed of an integrated circuit (IC) is provided on the substrate 102. Alternatively, it may be disposed on the connector 114. In FIG. 1, an integrated circuit 116 is provided over a connector 114 as part of the gate side driver circuits 108 and 110 and the source side driver circuit 112.

  The connector 114 has a function of supplying power from a power source and supplying various signals from an external circuit (not shown) to the gate side driving circuits 108 and 110 and the source side driving circuit 112. A flexible printed circuit (FPC) may be used as the connector 114. A signal from an external circuit is supplied to each pixel 106 via the gate side driving circuits 108 and 110 and the source side driving circuit 112, and an image is reproduced on the display area 104.

  Next, a schematic configuration of the pixel 106 will be described with reference to FIGS. 2 and 3, the thin film transistor 5 is provided on the first substrate 12. The thin film transistor 5 basically includes an active layer 14, a gate insulating film 16, a gate wiring 18, an interlayer insulating film 20, a source wiring 22 and a drain electrode 24. A well-known thing can be employ | adopted about the structure of the thin-film transistor 5, and the material of each part.

  A resin layer 26 is provided on the thin film transistor 5. The resin layer 26 has a role of flattening undulations on the first substrate 12 due to the formation of the thin film transistor 5. In the present embodiment, an acrylic resin is used as the resin layer 26, but the present invention is not limited to this.

  The resin layer 26 used in the present embodiment can be formed using a photosensitive resin composition. As such a photosensitive resin composition, it is preferable that the resolution is high and the pattern shape after exposure and development hardly changes even in the subsequent heat treatment step. The photosensitive resin composition that hardly changes the pattern shape even in the heat treatment step is preferably a composition containing a resin having high heat resistance. Examples of the resin having high heat resistance include a resin containing a cyclic aliphatic group or an aromatic group, or a resin containing a monomer component capable of giving a high glass transition temperature.

  As such a resin having high heat resistance, at least one resin selected from acrylic resins, siloxane resins, polyimide resins, and polyether resins is preferable. As the photosensitive resin composition containing such a resin having high heat resistance, Japanese Patent No. 3241399, Japanese Patent No. 4207604, Japanese Patent No. 4784283, Japanese Patent No. 4784283, Japanese Patent No. 4737209, Patent No. The photosensitive resin composition described in Japanese Patent No. 4637221, Japanese Patent No. 4232527, Japanese Patent No. 5176768, or the like can be applied.

  Moreover, when exposing the photosensitive resin composition layer and performing pattern formation, it is preferable to use a multitone mask called a halftone mask or a gray tone mask as a photomask. By using these masks, patterns having different film thicknesses can be formed by a single exposure process.

  Furthermore, after exposure and development, there is a step called “post-exposure” in which further exposure is performed to decompose the photosensitive agent present in the resin layer formed using the photosensitive resin composition. After this post-exposure, it is preferable to perform heating at about 100 ° C. for about 10 minutes. If the heating process is performed while the photosensitizer is present in the resin layer, it is considered that the photosensitizer inhibits the thermosetting property of the resin and lowers the Tg of the resin, which may greatly change the pattern shape. Therefore, after performing post-exposure and decomposing the photosensitive agent remaining in the resin layer, the heating process of about 100 ° C. described above is performed in advance before the heating process (baking process) of 200 ° C. or higher. The change in the shape of the pattern due to the above can be reduced. Thus, a desired pattern can be formed by combining the photosensitive resin composition and the post-exposure heating.

  The resin layer 26 of this embodiment is provided with an opening 28 for electrically connecting the pixel electrode 32 and the thin film transistor 5 and a groove 30 for embedding the first conductive layer 36 as an auxiliary electrode. . At this time, if the edges of the opening 28 and the groove 30 are broken during the baking of the resin layer 26, the opening 28 and the groove 30 are enlarged, and there is a risk that the aperture ratio of the pixel is sacrificed. For this reason, in the present embodiment, a resin material having a high glass transition point is used so that the edges of the opening 28 and the groove 30 do not collapse when the resin layer 26 is baked.

  The pixel electrode 32 is provided on the resin layer 26 and is connected to the drain electrode 24 of the thin film transistor 5 through the opening 28. As the pixel electrode 32, a light-transmitting metal oxide material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) can be used. Of course, the present invention is not limited to this, and any conductive material having translucency can be used.

  The groove 30 is a linear recess provided in the resin layer 26. The groove part 30 can be formed by removing the resin layer 26 halfway by a technique such as half etching. In the present embodiment, the trench 30 is arranged in a line along the gate wiring 18. Specifically, in FIG. 2, the trench 30 extends in the depth direction along the gate wiring 18 toward the drawing.

  The trench 30 and the pixel electrode 32 are covered with an insulating layer 34. As the insulating layer 34, an inorganic material containing silicon oxide or silicon nitride can be used. The insulating layer 34 is disposed between the pixel electrode 32 and a second conductive layer 38 as a common electrode to be described later, thereby electrically insulating the two.

  A first conductive layer 36 made of a metal material is disposed inside the groove 30. The first conductive layer 36 is made of a material having a higher conductivity than a second conductive layer 38 described later, and functions as an auxiliary wiring for reducing the resistance of the second conductive layer 38 substantially. In the present embodiment, the first conductive layer 36 is embedded so as to fill the inside of the groove 30 covered with the insulating layer 34. Therefore, the shape of the first conductive layer 36 of the present embodiment is the same as the shape of the groove 30, and has a configuration extending linearly along the gate wiring 18 as shown in FIG. 3.

  In the present embodiment, since the first conductive layer 36 is arranged along the gate wiring 18, the resistance of the second conductive layer 38 that functions as a common electrode to be described later can be reduced without sacrificing the aperture ratio. Can be planned. This is because the area above the gate wiring 18 is basically an area covered with the light shielding film 42 and does not contribute to image display.

  In the present embodiment, an example in which the first conductive layer 36 is provided so as to fit in the groove portion 30 is shown, but it is not strictly necessary to have such a structure, and the first conductive layer 36 is greatly increased from the upper surface of the resin layer 26. It doesn't have to be protruding or greatly dented. That is, even if the first conductive layer 36 is provided, the shape of the groove 30 and the shape of the first conductive layer 36 do not have to be exactly the same as long as the effect of planarization by the resin layer 26 is not significantly impaired. .

  A second conductive layer 38 made of a metal oxide material is disposed on the insulating layer 34. For example, as the second conductive layer 38, a light-transmitting conductive material such as ITO or IZO can be used. Of course, the present invention is not limited to this, and any conductive material having translucency can be used.

  The second conductive layer 38 of this embodiment functions as a common electrode to which a constant potential (common potential) is applied. Specifically, as shown in FIG. 3, the second conductive layer 38 includes a first portion 38 a extending along the gate wiring 18, and a second portion connected to the first portion 38 a and overlapping the pixel electrode 32. 38b. The first portion 38a is a portion disposed along the first conductive layer 36 and overlaps and contacts the first conductive layer 36 as shown in FIG. The second portion 38b includes a plurality of linearly patterned portions 38c, and the plurality of portions 38c overlap with the pixel electrode 32 through the insulating layer 34, respectively. That is, the second portion 38b functions as a common electrode.

  Due to such a structure, the first portion 38a is substantially reduced in resistance by the first conductive layer 36 functioning as an auxiliary wiring. That is, the resistance of the conductor portion constituted by the first portion 38a and the first conductive layer 36 is reduced as a whole. For this reason, the second portion 38b functioning as a common electrode in each pixel 106 is given a constant potential from the first portion 38a, so that variation in potential due to the wiring resistance of the second conductive layer 38 can be reduced.

  Returning to FIG. 2, a light-shielding film 42 and a color filter 44 are provided on the second substrate 40 disposed to face the first substrate 12. The light shielding film 42 may be formed of a metal film such as chromium, or may be formed of a resin material containing a black pigment. The color filter 44 can be made of a resin material containing a pigment (pigment or dye) having absorption at a specific wavelength.

  The structure based on the first substrate 12 described above is referred to as an array substrate in this specification. A structure based on the second substrate 40 is referred to as a counter substrate in this specification. In FIG. 2, a liquid crystal layer 46 is disposed between the array substrate 120 and the counter substrate 130. Although not shown in FIG. 2, the liquid crystal layer 46 is provided with a spacer for maintaining a cell gap. Although not shown in FIG. 2, an alignment film is provided in a portion in contact with the liquid crystal layer 46 in the array substrate 120 and the counter substrate 130.

  The liquid crystal display device 100 of the present embodiment described above has a structure in which the first conductive layer 36 is provided as an auxiliary wiring in order to reduce the resistance of the second conductive layer 38 that functions as a common electrode. Then, by providing the resin layer 26 with the groove 30 in advance and embedding the first conductive layer 36 in the groove 30, it is possible to suppress the undulation caused by the auxiliary wiring. Thus, according to this embodiment, it is possible to reduce the resistance of the common electrode without impairing the flatness of the display region.

<Manufacturing method of display device>
A method for manufacturing the liquid crystal display device 100 of the present embodiment will be described. First, as shown in FIG. 4, the thin film transistor 5 is formed on the first substrate 12. In this embodiment, a glass substrate is used as the first substrate 12, and the active layer 14, the gate insulating film 16, the gate wiring 18, the interlayer insulating film 20, the source wiring 22, and the drain electrode 24 are formed by a known manufacturing process. Since the method of forming the thin film transistor 5 is a known manufacturing process, detailed description thereof is omitted.

  Next, after applying the positive photosensitive resin material 25 which is the raw material of the resin layer 26 described above so as to cover the thin film transistor 5, a photosensitive process using a halftone mask 501 is performed, and ultraviolet light is not shielded. And a second photosensitive region 25b in which the amount of ultraviolet light irradiation is reduced by the light shielding member. Although the halftone mask is exemplified here, the present invention is not limited to this, and any mask having a similar function may be used. For example, a gray tone mask may be used.

  Note that the second photosensitive region 25 b is a region that will later become the groove portion 30, and thus is formed in a linear shape along the gate wiring 18 in this embodiment. Specifically, in FIG. 5, the second photosensitive region 25 b extends along the gate wiring 18 in the depth direction toward the drawing.

  After forming the first photosensitive region 25a and the second photosensitive region 25b, the first photosensitive region 25a and the second photosensitive region 25b are removed with a developer, and the resin layer 26 is formed by baking with heat or ultraviolet rays. In this manner, as shown in FIG. 6, the resin layer 26 having the opening 28 and the groove 30 is formed. In the present embodiment, since the resin material having a high glass transition point is used as described above, the edge is not broken by baking and the opening 28 and the groove 30 can be formed at a steep angle.

  After forming the resin layer 26, as shown in FIG. 7, the transparent conductive film (ITO film in this embodiment) is processed by photolithography to form the pixel electrode 32. The pixel electrode 32 is connected to the drain electrode 24 of the thin film transistor 5 through the opening 28. Thereafter, an insulating layer 34 is formed so as to cover the trench 30 and the pixel electrode 32. As the insulating layer 34, an inorganic insulating film such as a silicon nitride film or a silicon oxide film is used.

  Next, as shown in FIG. 8, a first conductive layer 36 that functions as an auxiliary wiring is formed inside the groove 30 (strictly, inside the groove 30 covered with the insulating layer 34). The first conductive layer 36 is made of a material having a higher conductivity than the second conductive layer 38 described later. Specifically, the first conductive layer 36 of the present embodiment is made of a metal material.

  The formation of the first conductive layer 36 is not particularly limited, but for embedding the groove 30, for example, a method of forming a metal film by electrolytic plating or sputtering, followed by pattern formation by photolithography, or conductive ink by inkjet. The method of driving in can be used. Alternatively, the first conductive layer 36 may be formed by filling the groove 30 with a resin material containing a conductive material as long as the condition that the second conductive layer 38 has a higher conductivity is satisfied.

  After forming the first conductive layer 36, a second conductive layer 38 functioning as a common electrode is formed. In FIG. 9, a first portion 38a disposed along the gate wiring 18 and a second portion 38b overlapping the pixel electrode 32 (specifically, a plurality of patterns patterned in a line constituting the second portion 38b). Portion 38c) is shown. The shape of the second conductive layer 38 in plan view is as shown in FIG.

  At this time, the second conductive layer 38 is in contact with and electrically connected at the portion overlapping the first conductive layer 36. Therefore, the second conductive layer 38 can use the first conductive layer 36 having higher conductivity as an auxiliary wiring, and the resistance is reduced as a whole.

  Through the process described above, the array substrate 120 shown in FIG. 2 is completed. Thereafter, the counter substrate 130 shown in FIG. 2 is bonded with a sealant or the like, and the liquid crystal layer 46 is injected between the array substrate 120 and the counter substrate 130. Thereby, the liquid crystal display device 100 shown in FIG. 2 is completed.

(Second Embodiment)
FIG. 10 is a plan view showing the configuration of the liquid crystal display device according to the second embodiment. The difference from the first embodiment is that, in the liquid crystal display device of the second embodiment, the shapes of the plurality of portions 52c constituting the second portion 52b of the second conductive layer 52 are different from those of the first embodiment. In addition, since it is the same structure as 1st Embodiment about another point, suppose that detailed description is abbreviate | omitted.

  In FIG. 10, the second conductive layer 52 includes a first portion 52 a disposed along the gate wiring 18 and a second portion 52 b disposed so as to overlap the pixel electrode 32. The second portion 52b is composed of a plurality of portions 52c that are linearly patterned, and each of the plurality of portions 52c has a linear pattern having a bent portion.

  With such a shape, the horizontal electric field formed between the pixel electrode 32 and the second conductive layer 52 as the common electrode is formed in a plurality of directions, so that the viewing angle can be further improved. Is possible.

  In the present embodiment, an example in which a plurality of portions 52c, which are linear patterns having bent portions, are arranged as common electrodes at positions overlapping with the pixel electrodes 32 has been described, but other than linear patterns having bent portions. As an example, a shape like a fish bone (generally called a fishbone shape) may be adopted.

(Third embodiment)
FIG. 11 is a plan view showing the configuration of the liquid crystal display device according to the third embodiment. FIG. 12 is a cross-sectional view showing the configuration of the liquid crystal display device according to the third embodiment. The difference from the first embodiment is that the first portion 54 a of the second conductive layer 54 is provided along the source wiring 22 of the thin film transistor 5 in the liquid crystal display device of the third embodiment. In addition, since it is the same structure as 1st Embodiment about another point, suppose that detailed description is abbreviate | omitted.

  In FIG. 11, the first portion 54 a of the second conductive layer 54 extends along the source line 22. Further, the second portion 54 b of the second conductive layer 54 is connected to the first portion 54 a and overlaps the pixel electrode 32. That is, the plurality of portions 54 c constituting the second portion 54 b are configured to extend substantially parallel to the gate wiring 18.

  FIG. 12 corresponds to a cross section obtained by cutting the plan view shown in FIG. 11 along B-B ′. As shown in FIG. 12, the first conductive layer 36 filled in the groove 30 is disposed on the source wiring 22. Since the upper portion of the source wiring 22 is finally shielded by the light shielding film 42, it does not contribute to image display. Therefore, in the present embodiment, by disposing the first conductive layer 36 along the source wiring, the resistance of the second conductive layer 54 functioning as a common electrode can be reduced without impairing the aperture ratio.

  In the present embodiment, the example in which the first conductive layer 36 is disposed above the source wiring 22 has been described. However, the first conductive layer 36 extends along both the gate wiring 18 and the source wiring 22. It is also possible. That is, in this case, the first conductive layer 36 is arranged in a lattice shape. With such a configuration, the dead space shielded by the light shielding film 42 can be utilized more effectively, and the resistance of the second conductive layer 54 can be further reduced.

  Further, the configuration of the second embodiment is applied to the second conductive layer 54 of the present embodiment, and a plurality of portions 54c constituting the second portion 54b of the second conductive layer 54 are linearly formed with bent portions, respectively. A pattern is also possible. The effects of such a configuration are as described in the second embodiment.

(Fourth embodiment)
FIG. 13 is a cross-sectional view showing the configuration of the liquid crystal display device according to the fourth embodiment. FIG. 14 is a plan view showing the configuration of the liquid crystal display device according to the fourth embodiment. FIG. 13 corresponds to a cross section obtained by cutting the plan view shown in FIG. 14 along CC ′. The difference from the first embodiment is that in the liquid crystal display device of the fourth embodiment, the arrangement of the pixel electrode and the common electrode is opposite to that of the first embodiment. In addition, since it is the same structure as 1st Embodiment about another point, suppose that detailed description is abbreviate | omitted.

  In FIG. 13, the resin layer 26 is provided with an opening 28 and a groove 30. The groove 30 is filled with the first conductive layer 62. In the present embodiment, as in the first embodiment, the groove 30 and the first conductive layer 62 are arranged so as to extend along the gate wiring 18. However, unlike the first embodiment, the insulating layer 66 is not disposed inside the groove 30.

  A second conductive layer 64 that functions as a common electrode is provided on the resin layer 26. Unlike the first embodiment, the second conductive layer 64 of this embodiment is provided immediately above the resin layer 26. Therefore, the second conductive layer 64 disposed at a position overlapping the first conductive layer 62 is electrically connected by being in contact with the first conductive layer 62. As a result, the second conductive layer 64 can be used by using the first conductive layer 62 as an auxiliary wiring.

  The second conductive layer 64 has a slightly larger opening 64 a so as not to overlap with the opening 28 of the resin layer 26. In other words, it can be said that the opening 28 is provided inside the opening 64 a provided in the second conductive layer 64.

  An insulating layer 66 is disposed on the second conductive layer 64. At this time, an opening 66 a is also provided in the insulating layer 66. As shown in FIG. 13, the diameter of the opening 66 a provided in the insulating layer 66 is larger than the diameter of the opening 28 of the resin layer 26 and smaller than the diameter of the opening 64 a of the second conductive layer 64.

  A pixel electrode 68 is provided on the insulating layer 66. The pixel electrode 68 is connected to the drain electrode 24 of the thin film transistor 5 through the opening 64a and the opening 28 provided in the resin layer 26 inside the opening 66a. Further, the pixel electrode 68 of the present embodiment has a comb shape. Specifically, like the second conductive layer 38 in the first embodiment, a first portion 68 a extending along the gate wiring 18, and a first portion 68 a connected to the first portion 68 a and overlapping the second conductive layer 64. Two portions 68b. The second portion 68b includes a plurality of portions 68c that are linearly patterned, and each of the plurality of portions 68c overlaps the second conductive layer 64 via the insulating layer 66.

  As described above, the position of the pixel electrode 68 and the second conductive layer 64 functioning as a common electrode is opposite to that of the first embodiment, but a lateral electric field can be applied to the liquid crystal layer 46 without any particular problem. it can. Also in this case, the first conductive layer 62 embedded in the resin layer 26 can be used as an auxiliary wiring for the second conductive layer 64, and the resistance of the common electrode is reduced without impairing the flatness of the display region. It is possible.

  The configuration of the present embodiment can also be used in combination with the configuration of the second embodiment or the third embodiment.

  In this embodiment, the case of an organic EL display device has been exemplified as a disclosure example. However, as other application examples, a self-light emitting device other than the organic EL display device, a liquid crystal display device, or an electronic paper type having an electrophoretic element or the like Any flat panel display device such as a display device may be used. Further, the present invention can be applied from medium to small size to large size without particularly limiting the size.

  The embodiments described above as the embodiments of the present invention can be implemented in appropriate combination as long as they do not contradict each other. Also, those in which those skilled in the art appropriately added, deleted, or changed the design based on the display device of each embodiment, or those in which the process was added, omitted, or changed in conditions are also included in the present invention. As long as the gist is provided, it is within the scope of the present invention.

  In addition, even for other operational effects different from the operational effects brought about by the aspects of the above-described embodiments, those that are apparent from the description of the present specification, or that can be easily predicted by those skilled in the art, Of course, it is understood that the present invention provides.

DESCRIPTION OF SYMBOLS 5 ... Thin-film transistor, 12 ... 1st board | substrate, 14 ... Active layer, 16 ... Gate insulating film, 18 ... Gate wiring, 20 ... Interlayer insulating film, 22 ... Source wiring, 24 ... Drain electrode, 24 ... Drain electrode, 25 ... Photosensitivity 25a ... first photosensitive region, 25b ... second photosensitive region, 26 ... resin layer, 28 ... opening, 30 ... groove, 32 ... pixel electrode, 34 ... insulating layer, 36 ... first conductive layer, 38 ... 2nd conductive layer, 38a ... 1st part, 38b ... 2nd part, 38c ... Multiple parts, 40 ... 2nd board | substrate, 42 ... Light shielding film, 44 ... Color filter, 46 ... Liquid crystal layer, 100 ... Liquid crystal display device , 102 ... Substrate, 104 ... Display area, 106 ... Pixel, 108, 110 ... Gate side drive circuit, 112 ... Source side drive circuit, 114 ... Connector, 116 ... Integrated circuit, 120 ... Array substrate

Claims (18)

A thin film transistor on a substrate;
A resin layer on the thin film transistor;
A groove provided in the resin layer;
A first conductive layer embedded in the groove;
A second conductive layer provided on the resin layer, a part of which overlaps and contacts the first conductive layer, and has a higher conductivity than the first conductive layer;
A display device comprising:   2. The display device according to claim 1, further comprising a pixel electrode disposed to face the second conductive layer via an insulating layer and connected to the thin film transistor.   The display device according to claim 2, wherein the insulating layer is disposed between the resin layer and the second conductive layer and covers the pixel electrode.   The display device according to claim 3, wherein the insulating layer covers the inside of the groove.   The display device according to claim 2, wherein the insulating layer covers the second conductive layer. The second conductive layer has a first opening,
The display device according to claim 5, wherein the pixel electrode is connected to the thin film transistor through a second opening provided in the resin layer inside the first opening.   The display device according to claim 6, wherein the insulating layer has a third opening inside the first opening. The thin film transistor is connected to a gate wiring extending in a row direction and a source wiring extending in a column direction,
3. The second conductive layer according to claim 2, wherein the second conductive layer includes a first portion extending along the gate wiring or the source wiring, and a second portion connected to the first portion and overlapping the pixel electrode. Display device.   The display device according to claim 8, wherein the first conductive layer is provided along the first portion of the second conductive layer.   The display device according to claim 8, wherein the second portion of the second conductive layer includes a plurality of portions patterned in a linear shape.   The display device according to claim 1, wherein the second conductive layer is made of a metal oxide material.   The display device according to claim 11, wherein the first conductive layer is made of a metal material. A thin film transistor is formed on the substrate,
Forming a resin layer on the thin film transistor;
Forming a groove in the resin layer;
Filling the inside of the groove with a first conductive layer;
Forming a second conductive layer, a part of which overlaps and contacts the first conductive layer on the resin layer;
A method for manufacturing a display device.   The method for manufacturing a display device according to claim 13, wherein an opening reaching the thin film transistor is formed in the resin layer simultaneously with forming the groove in the resin layer.   The method for manufacturing a display device according to claim 14, wherein a halftone mask or a gray tone mask is used to form the groove and the opening.   The method for manufacturing a display device according to claim 13, wherein the first conductive layer is formed by an electrolytic plating method when the inside of the groove is filled with the first conductive layer.   The method for manufacturing a display device according to claim 13, wherein the second conductive layer is made of a metal oxide material.   The display device manufacturing method according to claim 17, wherein the first conductive layer is made of a metal material.

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