JP2016009088A - Display device and manufacturing method of display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device that has excellent insulating properties and can prevent entry of bubbles to obtain good adhesion, and a manufacturing method of a display device.SOLUTION: A display device has a circuit board 30 including a pixel circuit having a pixel electrode formed thereon and a display sheet including an opposing electrode capable of applying a voltage between the pixel electrode and the opposing electrode, which are bonded with an adhesive layer therebetween. The circuit board 30 includes convex structure parts 95 and coating films 76 coating the convex structure parts 95; the coating film 76 has a concave-convex part 80 including a concave part 81 and a convex part 82 formed on a bonding surface on the adhesive layer; the convex structure parts 95 are formed to be overlapped on the convex parts 82.

Description

  The present invention relates to a display device and a method for manufacturing the display device.

  2. Description of the Related Art Conventionally, as a display device, an electrophoretic display device in which a circuit substrate in which a pixel electrode is formed on a circuit including switching elements and an electrophoretic layer are bonded via an adhesive layer is known (for example, a patent) Reference 1). When manufacturing such an electrophoretic display device, a sheet-like electrophoretic sheet (display sheet) is generally formed by adhering to a circuit board with an adhesive.

JP 2009-230061 A

  However, in the electrophoretic display device as described above, when the electrophoretic sheet is bonded through the adhesive layer, the upper surface of the circuit board is a flat surface, so that air bubbles enter between the circuit board and the adhesive layer. As a result, the adhesion of the electrophoretic sheet may be reduced.

  Conventionally, the surface of a circuit board is covered with a planarizing film, but the film thickness of the planarizing film is reduced by the protrusions caused by the intersections of the semiconductor layer, the gate wiring, and the source wiring, There is a risk that defects such as display defects may occur due to a decrease in insulation.

  One aspect of the present invention has been made to solve the above-described problem, and is a display device and display capable of obtaining excellent adhesiveness by being excellent in insulation and preventing bubbles from entering. An object is to provide a method for manufacturing a device.

  According to the first aspect of the present invention, a circuit board including a pixel circuit on which a pixel electrode is formed and a display sheet including a counter electrode capable of applying a voltage between the pixel electrode are interposed via an adhesive layer. In the bonded display device, the circuit board includes a convex structure portion and a coating film that covers the convex structure portion, and the coating film has a concave portion and a convex shape on a bonding surface with the adhesive layer. A display device is provided in which an uneven portion including a portion is formed, and the convex structure portion is formed to overlap the convex portion.

According to the display device according to the first aspect, bubbles generated when the display sheet is bonded to the circuit board are discharged to the outside along the concave portions of the concave and convex portions. Accordingly, since bubbles are prevented from entering the adhesive layer, a decrease in adhesion due to the entry of bubbles is prevented. Therefore, the adhesiveness in an adhesive layer and an uneven | corrugated | grooved part improves more, and a display sheet will be favorably bonded to a circuit board through the adhesive layer.
Further, since the convex structure portion is formed so as to overlap the convex portion, the film thickness of the coating film is sufficiently ensured even when the concave and convex portion is formed. Therefore, a highly reliable display device having excellent display quality due to excellent insulation is provided.

Further, in the display device according to the first aspect, in the state in which the concavo-convex portion is viewed in plan, a decrease due to the concave portion from the uppermost surface of the coating film is the thickness of the thickest portion of the coating film. It is good also as a structure currently formed so that the said convex structure part may overlap in the area | region used as 10% or less.
According to this configuration, since the convex structure portion is arranged in a region where the decrease due to the concave portion from the uppermost surface of the coating film is 10% or less of the thickness of the thickest portion of the coating film, the concave and convex portions are formed. Even if it is a case, the film thickness of a coating film is fully ensured. Therefore, a highly reliable display device having excellent display quality due to excellent insulation is provided.

  According to the second aspect of the present invention, a circuit board including a pixel circuit on which a pixel electrode is formed and a display sheet including a counter electrode capable of applying a voltage between the pixel electrode are interposed via an adhesive layer. In the bonded display device, the circuit board includes a convex structure portion and a coating film that covers the convex structure portion, and the coating film has a concave portion and a concave portion on a bonding surface with the adhesive layer. A display device is provided in which the concavo-convex portion is formed, and the concavo-convex portion is formed so that the concave portion does not overlap the convex structure portion in a plan view.

According to the display device according to the second aspect, bubbles generated when the display sheet is bonded to the circuit board are discharged to the outside along the concave portions of the concave and convex portions. Accordingly, since bubbles are prevented from entering the adhesive layer, a decrease in adhesion due to the entry of bubbles is prevented. Therefore, the adhesiveness in an adhesive layer and an uneven | corrugated | grooved part improves more, and a display sheet will be favorably bonded to a circuit board through the adhesive layer.
Moreover, since the convex structure portion does not overlap with the concave portion of the concavo-convex portion, the film thickness of the coating film is sufficiently ensured even when the concavo-convex portion is formed. Therefore, a highly reliable display device having excellent display quality due to excellent insulation is provided.

In the first and second aspects, the circuit board includes a semiconductor layer, a scanning line, and a data line, and the convex structure portion has the semiconductor layer, the scanning line, and the data line in a plan view. It is good also as a structure comprised by overlapping at least two of these.
According to this configuration, insulation can be ensured at the intersection of the semiconductor layer, the scanning line, and the data wiring.

In the first and second aspects, the display sheet may be an electrophoretic sheet.
According to this configuration, an electrophoretic display device in which an electrophoretic sheet is favorably bonded to a circuit board by preventing air bubbles from entering is provided. In addition, an electrophoretic display device excellent in display quality can be provided by ensuring insulation by securing the film thickness of the coating film.

  According to the third aspect of the present invention, a voltage can be applied between the pixel electrode and the pixel circuit on which the pixel electrode is formed, the convex structure portion, and a circuit board including a coating film covering the convex structure portion, and the pixel electrode. In the method for manufacturing a display device in which a display sheet including a counter electrode is bonded via an adhesive layer, the circuit board forming step includes a concave and convex portion including a concave portion and a convex portion on a bonding surface with the adhesive layer. A method of manufacturing a display device in which the concavo-convex portion is formed so that the convex structure portion and the convex portion overlap with each other.

According to the method for manufacturing a display device according to the third aspect, bubbles generated when the display sheet is bonded to the circuit board can be discharged to the outside along the concave portion of the concave and convex portion. Therefore, since bubbles are prevented from entering the adhesive layer, it is possible to prevent a decrease in adhesion due to the bubbles.
Further, since the convex structure portion is formed so as to overlap the convex portion, the film thickness of the coating film is sufficiently ensured even when the concave and convex portion is formed. Therefore, a highly reliable display device having excellent display quality due to excellent insulation is provided.

Further, in the method for manufacturing a display device according to the third aspect, the unevenness forming step may be configured such that, when viewed in plan, a decrease due to the concave portion from the uppermost surface of the coating film is a thickest portion of the coating film. It is good also as a structure which forms the said uneven | corrugated | grooved part so that the said convex structure part of the said circuit board may overlap in the area | region used as 10% or less of this thickness.
According to this configuration, since the convex structure portion is disposed in a region where the decrease from the uppermost surface of the coating film is 10% or less of the thickness of the thickest portion of the coating film, Even so, the film thickness of the coating film can be sufficiently secured. Therefore, a highly reliable display device having good display quality can be manufactured by being excellent in insulation.

  According to the fourth aspect of the present invention, a voltage can be applied between the pixel electrode on which the pixel electrode is formed, the circuit structure including the convex structure portion, and the covering film covering the convex structure portion, and the pixel electrode. In the method for manufacturing a display device in which a display sheet including a counter electrode is bonded via an adhesive layer, the circuit board forming step includes a concave and convex portion including a concave portion and a convex portion on a bonding surface with the adhesive layer. A method of manufacturing a display device that forms the concavo-convex portion so that the concave portion does not overlap the convex structure portion in a plan view.

According to the method for manufacturing a display device according to the fourth aspect, bubbles generated when the display sheet is bonded to the circuit board can be discharged to the outside along the concave portion of the concave and convex portion. Therefore, since bubbles are prevented from entering the adhesive layer, it is possible to prevent a decrease in adhesion due to the bubbles.
Moreover, since the convex structure portion does not overlap with the concave portion of the concavo-convex portion, a sufficient film thickness of the coating film can be ensured even when the concavo-convex portion is formed. Therefore, a highly reliable display device having good display quality can be manufactured by being excellent in insulation.

In the third and fourth aspects, the circuit board includes a semiconductor layer, a scanning line, and a data line, and the convex structure portion has the semiconductor layer, the scanning line, and the data line in a plan view. It is good also as a structure comprised by overlapping at least two of these.
According to this configuration, insulation can be ensured at the intersection of the semiconductor layer, the scanning line, and the data line.

In the third and fourth aspects, the display sheet may be an electrophoretic sheet.
According to this configuration, an electrophoretic display device in which an electrophoretic sheet is favorably bonded to a circuit board by preventing air bubbles from entering is provided. In addition, an electrophoretic display device excellent in display quality can be provided by ensuring insulation by securing the film thickness of the coating film.

It is an equivalent circuit diagram which shows an electrophoretic display device. It is sectional drawing of an electrophoretic display apparatus. It is sectional drawing of the microcapsule which comprises an electrophoretic element. (A), (b) is a figure for demonstrating operation | movement of an electrophoretic element. It is sectional drawing which shows the principal part structure of an element substrate. (A), (b), (c) is a figure which shows an example of the planar structure of an uneven | corrugated | grooved part. (A), (b) is the figure which showed the positional relationship of an uneven | corrugated | grooved part and a convex structure part. It is sectional drawing for demonstrating the tolerance | permissible_width | variety of the positional relationship of a convex structure part and a recessed part. It is a top view for demonstrating the allowable width | variety of the positional relationship of a convex structure part and a recessed part. (A)-(c) is a figure which shows an example of the manufacturing process of an electrophoretic display device.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In addition, in the drawings used in the following description, in order to make the features easy to understand, there are cases where the portions that become the features are enlarged for the sake of convenience, and the dimensional ratios of the respective components are not always the same as the actual ones. Absent.

This embodiment illustrates an active matrix type electrophoretic display device as an example of a display device.
FIG. 1 is an equivalent circuit diagram showing an electrophoretic display device of this embodiment. FIG. 2 is a sectional view of the electrophoretic display device. FIG. 3 is a cross-sectional view of a microcapsule constituting an electrophoretic element. 4A and 4B are diagrams for explaining the operation of the electrophoretic element.

As shown in FIG. 1, the electrophoretic display device 100 according to the present embodiment includes a display unit 5 in which a plurality of pixels 40 are arranged in a matrix in the row direction and the column direction. Around the display unit 5, a scanning line driving circuit 61 and a data line driving circuit 62 are arranged. The display unit 5 is provided with a plurality of scanning lines 36 extending from the scanning line driving circuit 61 and a plurality of data lines 38 extending from the data line driving circuit 62, and the pixels 40 correspond to these intersecting positions. Is provided. Each pixel 40 is provided with a selection transistor 41 and a pixel electrode 35.
Note that the “row direction” is the “horizontal direction” in the display unit, and corresponds to the horizontal direction in FIG. The “column direction” is a “vertical direction” orthogonal to the horizontal direction and corresponds to the vertical direction in FIG.

  The scanning line driving circuit 61 is connected to each pixel 40 via m scanning lines 36 (G1, G2,..., Gm), and sequentially selects the scanning lines 36 from the first row to the m-th row. A selection signal defining the timing for turning on the selection transistor 41 provided in the pixel 40 is supplied via the selected scanning line 36. The data line driving circuit 62 is connected to each pixel 40 via n data lines 38 (S1, S2,..., Sn), and receives an image signal that defines pixel data corresponding to each pixel 40. The pixel 40 is supplied.

  As shown in FIG. 2, the electrophoretic display device 100 has an element substrate 30 (circuit board), a counter substrate 31, and a plurality of microcapsules 20 sandwiched between the element substrate 30 and the counter substrate 31. An electrophoretic element 32.

  In the present embodiment, the electrophoretic element 32 and the pixel electrode 35 are bonded via the adhesive layer 50, whereby the element substrate 30 and the counter substrate 31 are bonded. The electrophoretic element 32 is generally formed on the counter substrate 31 side in advance and is handled as an electrophoretic sheet (display sheet) 51 including the adhesive layer 50. In the present embodiment, the electrophoretic sheet 51 is composed of a sheet body including the adhesive layer 50, the electrophoretic element 32, the counter electrode 37, and the substrate body 79.

  In the manufacturing process described later, the electrophoretic sheet 51 is handled in a state where a protective release sheet is attached to the surface of the adhesive layer 50. Then, the display unit 5 is formed by attaching the electrophoretic sheet 51 from which the release sheet is peeled off to the element substrate 30 on which the pixel electrode 35, the selection transistor 41, various circuits, and the like are separately formed. For this reason, the adhesive layer 50 exists only on the pixel electrode 35 side.

  The element substrate 30 includes a plurality of pixel electrodes 35 provided corresponding to the respective pixels 40. The pixel electrode 35 is made of, for example, a transparent conductive material such as ITO (indium tin oxide) or a metal material such as Al, and applies a voltage to the electrophoretic element 32 with the counter electrode 37 described later. Electrode.

  The counter substrate 31 includes a substrate body 79 and a counter electrode 37. The substrate body 79 is a substrate made of glass, plastic, or the like, and is disposed on the viewing side, so that a transparent substrate is used. A counter electrode 37 is formed on one surface of the substrate body 79 on the side of the electrophoretic element 32 so as to face each pixel electrode 35. The counter electrode 37 is an electrode that applies a voltage to the electrophoretic element 32 together with the pixel electrode 35, and is made of a transparent conductive material such as MgAg (magnesium silver), ITO, or IZO (indium / zinc oxide).

  As shown in FIG. 3, the microcapsule 20 has a particle size of, for example, about 50 μm, and has a dispersion medium 21, a large number of white particles (electrophoretic particles) 27, and a large number of black particles (electrophoresis). Particles) 26 are encapsulated spherical bodies. As shown in FIG. 2, the microcapsule 20 is sandwiched between the counter electrode 37 and the pixel electrode 35, and a plurality of microcapsules 20 are arranged in one pixel 40. 2 shows a configuration in which a plurality of microcapsules 20 are arranged in one pixel 40, a configuration in which one microcapsule 20 is arranged in one pixel 40 may be used. .

  The outer shell portion 20a (wall film) of the microcapsule 20 is formed using an acrylic resin such as polymethyl methacrylate or polyethyl methacrylate, a translucent polymer resin such as a urea resin, or gum arabic. Yes. The dispersion medium 21 is a liquid that disperses the white particles 27 and the black particles 26 in the microcapsules 20.

  Examples of the dispersion medium 21 include water, alcohol solvents (methanol, ethanol, isopropanol, butanol, octanol, methyl cellosolve, etc.), esters (ethyl acetate, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). ), Aliphatic hydrocarbons (pentane, hexane, octane, etc.), alicyclic hydrocarbons (cyclohexane, methylcyclohexane, etc.), aromatic hydrocarbons (benzene, toluene, benzenes having a long-chain alkyl group ( Xylene, hexylbenzene, hebutylbenzene, octylbenzene, nonylbenzene, decylbenzene, undecylbenzene, dodecylbenzene, tridecylbenzene, tetradecylbenzene)), halogenated hydrocarbons (methylene chloride, chloroform, tetrachloride) Element, and 1,2-dichloroethane), can be exemplified a carboxylate, it may be other oils. These substances can be used alone or as a mixture, and a surfactant or the like may be further blended.

  The white particles 27 are particles (polymer or colloid) made of a white pigment such as titanium dioxide, zinc white, and antimony trioxide, and are used, for example, by being negatively charged. The black particles 26 are particles (polymer or colloid) made of a black pigment such as aniline black or carbon black, and are used by being charged positively, for example.

If necessary, these white pigments and black pigments may include electrolytes, surfactants, metal soaps, resins, rubbers, oils, varnishes, compound charge control agents, titanium-based coupling agents, aluminum-based cups. A dispersing agent such as a ring agent and a silane coupling agent, a lubricant, a stabilizer, and the like can be added.
Further, instead of the black particles 26 and the white particles 27, for example, pigments such as red, green, blue, yellow, cyan, magenta and the like may be used. According to such a configuration, red, green, blue, yellow, cyan, magenta, and the like can be displayed on the display unit 5 without using a color filter.
Instead of the above configuration, a one-particle system in which one type of charged particle is dispersed in the colored dispersion medium 21 may be used. Alternatively, a configuration in which two or more kinds of charged particles are dispersed in the colored dispersion medium 21 may be used.
Further, instead of the configuration in which the dispersion medium and particles are enclosed in the microcapsule, a configuration in which the dispersion medium and particles are filled between a pair of substrates may be used. In this case, a partition wall is provided between the pair of substrates. The dispersion medium and the particles may be filled in the cells partitioned by the partition walls.

  In the electrophoretic element 32 configured as described above, when the pixel 40 is displayed in white, as shown in FIG. 4A, the counter electrode 37 is held at a relatively high potential, and the pixel electrode 35 is relatively lowered. Hold at potential. That is, when the potential of the counter electrode 37 is set as a reference potential, the pixel electrode 35 is held negative. Thereby, the negatively charged white particles 27 are attracted to the counter electrode 37, while the positively charged black particles 26 are attracted to the pixel electrode 35. As a result, when this pixel is viewed from the counter electrode 37 side, white is visually recognized.

  On the other hand, when the pixel 40 is displayed in black, as shown in FIG. 4B, the counter electrode 37 is held at a relatively low potential, and the pixel electrode 35 is held at a relatively high potential. That is, when the potential of the counter electrode 37 is set as a reference potential, the pixel electrode 35 is kept positive. As a result, the positively charged black particles 26 are attracted toward the counter electrode 37, while the negatively charged white particles 27 are attracted to the pixel electrode 35. As a result, when this pixel is viewed from the counter electrode 37 side, black is visually recognized.

Next, the configuration of the element substrate 30 will be described in detail. FIG. 5 is a cross-sectional view showing the main configuration of the element substrate 30.
As shown in FIG. 5, the scanning line 36, the data line 38, the selection transistor 41, and the like shown in FIG. 1 are formed on the surface of the element substrate 30 on which the electrophoretic element 32 is disposed.

  The substrate body 71 constituting the element substrate 30 is made of glass, plastic, or the like. Since the substrate body 71 is disposed on the side opposite to the viewing side, it does not have to be transparent. A semiconductor layer 72 is formed on one surface of the substrate body 71 on the electrophoretic element 32 side, and a gate insulating film 73 is formed so as to cover the semiconductor layer 72. The semiconductor layer 72 includes, for example, non-single-crystal silicon materials such as amorphous silicon and polycrystalline silicon, oxide semiconductor materials, transparent oxide semiconductor materials such as In—Ga—Zn—O, and organic substances such as fluorene-bithiophene copolymers. A semiconductor material or the like can be used. When an oxide semiconductor material is used for the semiconductor layer 72, an oxide insulating material is preferably used for the gate insulating film 73. When an organic semiconductor material is used for the semiconductor layer 72, the gate insulating film 73 is used. It is also desirable to use an organic insulating material.

  On the gate insulating film 73, the scanning line 36 that functions as the gate electrode of the selection transistor 41 is formed. For the scanning line 36, for example, a metal laminated film of an Al—Nd alloy and Mo can be used. In addition, Al alone, ITO, Cu, Cr, Ta, Mo, Nb, Ag, Pt, Pd, In, Nd, and alloys thereof can be used.

  A first interlayer insulating film 74 is formed on the entire surface of the substrate body 71 so as to cover the scanning lines 36. For the first interlayer insulating film 74, for example, an inorganic insulating material such as a silicon nitride film, a silicon oxide film, or a silicon nitride oxide film, or an organic insulating material can be used. A data line 38 electrically connected to the source region of the semiconductor layer 72 through the contact hole 75 is formed on the first interlayer insulating film 74. A drain line (drain electrode) 65 that is electrically connected to the drain region of the semiconductor layer 72 through the contact hole 77 is formed on the first interlayer insulating film 74. The same material as that of the scanning line 36 can be used for the data line 38 and the drain line 65. 5 has a top gate structure in which the gate electrode is formed above the semiconductor layer 72 in FIG. 5, the bottom gate structure in which the gate electrode is formed below the semiconductor layer 72. Also good.

  A second interlayer insulating film 76 is formed on the entire surface of the first interlayer insulating film 74 so as to cover the data lines 38 and the drain lines 65. As the first interlayer insulating film 74, for example, an inorganic insulating material such as a silicon nitride film, a silicon oxide film, or a silicon nitride oxide film, or an organic insulating material can be used for the second interlayer insulating film 76. A pixel electrode 35 electrically connected to the drain region of the semiconductor layer 72 through the contact hole 78 and the drain line 65 is formed on the second interlayer insulating film 76. Here, although the planar shape of the pixel electrode 35 is not illustrated, the data line 38 and the scanning line 36 are formed in a substantially rectangular shape in accordance with the substantially orthogonal arrangement.

  Incidentally, in the electrophoretic display device 100 of the present embodiment, the electrophoretic element 32 and the pixel electrode 35 are bonded via the adhesive layer 50 as shown in FIG. Are joined. Therefore, in the electrophoretic display device 100, it is desired to improve the adhesion in the adhesive layer 50 and to prevent the entrapment of bubbles during bonding. This is because if the adhesiveness of the adhesive layer 50 is lowered, the mechanical strength is lowered, so that the reliability of the apparatus is lowered. Further, when bubbles are caught in the adhesive layer 50, the display quality is deteriorated.

  On the other hand, in the present embodiment, the concavo-convex portion 80 is formed on the upper surface of the second interlayer insulating film 76, that is, the bonding surface with the electrophoretic sheet 51. The uneven portion 80 includes a concave portion 81 and a convex portion 82. The pixel electrode 35 has an uneven shape that follows the shape of the uneven portion 80.

In the present embodiment, the upper surface of the convex portion 82 is formed smaller than the pixel electrode 35 as shown in FIG. Specifically, the upper surface of the convex portion 82 only needs to have a planar area (area in plan view) of 20 μm ² or more. Further, it is desirable that the height of the convex portion 82 with respect to the concave portion 81 is set to 1.0 μm or more in the concave-convex portion 80. In this embodiment, when the concave portion 80 is set to about 1.5 μm, entry of bubbles is prevented. As a result, good adhesion could be obtained. The recess 81 is formed so as to communicate with the outside of the display unit 5.

  Further, in the present embodiment, the size of the electrophoretic sheet 51 bonded to the element substrate 30 by the adhesive layer 50 is larger than the size of the formation region (second interlayer insulating film 76) of the uneven portion 80. Therefore, the adhesive layer 50 covers the side end surface of the second interlayer insulating film 76. Further, the sealing material 60 seals the display unit 5 and the peripheral circuit unit 6 so as to be in contact with the adhesive layer 50. According to this configuration, since the outer edge portion of the concavo-convex portion 80 (second interlayer insulating film 76) is covered with the adhesive layer 50 and the sealing material 60, the entry of moisture into the second interlayer insulating film 76 is prevented. Sealability can be obtained.

  Moreover, in the uneven | corrugated | grooved part 80, it is desirable to set the area ratio of the recessed part 81 and the convex part 82 to 10 to 90%.

The planar structure of the uneven portion 80 will be described. FIGS. 6A, 6 </ b> B, and 6 </ b> C are diagrams illustrating an example of a planar structure of the uneven portion 80.
In the concavo-convex portion 80, the flat surface shape of the upper surface 82a of the convex portion 82 may be a hexagon as shown in FIG. 6A, or may be a circle as shown in FIG. A rectangle (square) as shown in FIG. In addition, not only these shapes but the upper surface of a convex part should just be a flat surface.

  Meanwhile, as shown in FIG. 5, the semiconductor substrate 72, the scanning line 36, and the data line 38 are formed on the element substrate 30 below the second interlayer insulating film 76. Since the semiconductor layer 72, the scanning line 36, and the data line 38 are formed in a predetermined region in the display unit 5, they are partially crossed on the substrate in a plan view. From the above, the element substrate 30 is formed with a convex structure that protrudes upward in comparison with other portions at a portion where at least two of the semiconductor layer 72, the scanning line 36, and the data line 38 intersect in a plane. Yes.

  On the other hand, in the present embodiment, the concavo-convex portion 80 is formed in the second interlayer insulating film 76 that becomes a bonding surface with the electrophoretic sheet 51 as described above. The second interlayer insulating film 76 is relatively thin in the recess 81 of the uneven portion 80. For this reason, when the convex structure formed on the element substrate 30 and the concave portion 81 of the concave and convex portion 80 overlap in a planar manner, the thickness of the second interlayer insulating film 76 is thinner than a predetermined thickness (minimum thickness). turn into. When the film thickness of the second interlayer insulating film 76 is reduced, the insulating property of the element substrate 30 is lowered, and a desired voltage cannot be applied to the electrophoretic element 32, causing problems such as display defects. there is a possibility. Further, the thin portion of the second interlayer insulating film 76 cannot fill a specific convex portion such as a foreign substance existing on the element substrate 30, and the foreign substance may be exposed on the surface. is there.

  Therefore, in the electrophoretic display device 100 according to the present embodiment, the second interlayer insulating film (coating film) 76 is adjusted by adjusting the planar positional relationship between the concavo-convex portion 80 and the convex structure formed on the element substrate 30. The film thickness was ensured. As a result, a desired voltage can be applied to the electrophoretic element 32, and problems such as display defects can be prevented. In addition, it is possible to reliably fill specific convex portions such as foreign matters existing on the element substrate 30.

  7 is a diagram showing a planar positional relationship between the concavo-convex portion 80 and the convex structure portion 95, FIG. 7 (a) is a diagram showing a planar configuration, and FIG. 7 (b) is a diagram of FIG. 7 (a). It is sectional drawing by the AA arrow in FIG. In FIG. 7, the case where the convex structure portion 95 is configured by the intersection of the scanning line 36 and the data line 38 is taken as an example. The convex structure portion 95 is not limited to the intersection of the scanning line 36 and the data line 38, but includes a structure constituted by at least two intersections of the scanning line 36, the data line 38, and the semiconductor layer 72. In other words, the convex structure portion 95 includes a portion formed by an intersection where all of the scanning line 36, the data line 38, and the semiconductor layer 72 intersect.

  In the present embodiment, as shown in FIGS. 7A and 7B, the concavo-convex portion 80 is formed so that the concave portion 81 of the second interlayer insulating film 76 does not overlap the convex structure portion 95 in a plane. . In other words, it can also be said that the convex part 82 is formed so as to overlap the convex structure part 95 in a planar manner. According to this, in the second interlayer insulating film 76, the concave portion 81 and the convex structure portion 95 whose thickness is reduced overlap. Since the convex part 82 and the convex structure part 95 whose film thickness are relatively thick do not overlap, it is possible to prevent the film thickness from becoming thin. Therefore, a desired voltage can be applied to the electrophoretic element 32, and problems such as display defects can be prevented. In addition, it is possible to reliably fill specific protrusions such as foreign substances existing on the element substrate 30.

  In the present embodiment, the concave portion 81 is formed so as not to completely overlap the convex structure portion 95 in a planar manner, that is, the convex portion 82 is formed to completely overlap the convex structure portion 95 in a planar manner. It is not limited to cases only. That is, as long as the predetermined film thickness of the second interlayer insulating film 76 can be ensured, the convex structure portion 95 may planarly overlap a part of the concave portion 81.

  FIG. 8 is a cross-sectional view for explaining the allowable width of the positional relationship between the convex structure portion 95 and the concave portion 81. FIG. 9 is a plan view for explaining the allowable width of the positional relationship between the convex structure portion 95 and the concave portion 81. In FIG. 9, the case where the convex structure portion 95 is configured by the intersection of the scanning line 36 and the data line 38 is taken as an example, but the present invention is not limited to this.

  As shown in FIG. 8, the concavo-convex portion 80 is located in the element substrate 30 in a region A where a decrease due to the concave portion 81 from the uppermost surface 76 a of the second interlayer insulating film 76 is 10% or less of the thickness H of the thickest portion. The convex structure portions 95 are formed so as to overlap each other. Here, the thickest portion of the second interlayer insulating film 76 corresponds to the maximum thickness from the upper surface of the first interlayer insulating film 74 to the upper surface of the convex portion 82 (uppermost surface 76a). That is, the concavo-convex portion 80 is formed so that the convex structure portion 95 overlaps a region where the second interlayer insulating film 76 has a film thickness of 90% (90%) or more of the maximum thickness.

  As shown in FIG. 9, an allowable area A <b> 1 in which the arrangement of the convex structure portion 95 is allowed is generated around the convex portion 82. Thus, even when the convex structure portion 95 overlaps with a part of the concave portion 81 in a plan view, it is possible to ensure a sufficient film thickness of the second interlayer insulating film 76 as long as it is within the allowable region A1. . Therefore, a desired voltage can be applied to the electrophoretic element 32, and problems such as display defects can be prevented. In addition, it is possible to reliably fill specific protrusions such as foreign substances existing on the element substrate 30.

  As described above, for example, the electrophoretic sheet 51 is bonded via the adhesive layer 50 as the region for adjusting the planar positional relationship between the concavo-convex portion 80 and the convex structure formed on the element substrate 30. It is most desirable to carry out over the entire upper surface of the element substrate 30. According to this, it is possible to ensure electrical insulation and reliably suppress the occurrence of display defects.

  The position adjustment is not necessarily performed over the entire upper surface of the element substrate 30. For example, the position adjustment may be performed at least in the display unit 5. According to this, electrical insulation is ensured and display defects occur. Can be reliably suppressed. Alternatively, the position adjustment may be performed at least in a region of the display unit 5 that overlaps the pixel electrode 35 in a planar manner, and according to this, electrical insulation can be ensured. Further, the position adjustment may be performed at least in a region of the display unit 5 that does not overlap the pixel electrode 35 in a planar manner, and according to this, it is possible to suppress the occurrence of display defects.

  In the present embodiment, the case where the convex structure portion 95 in the element substrate 30 is configured by at least two intersecting portions of the scanning line 36, the data line 38, and the semiconductor layer 72 is illustrated, but the present invention is not limited to this. In this case, for example, the position adjustment may be performed in an area having an intersection where at least a wiring for supplying a power supply voltage (hereinafter referred to as a power supply voltage line) is an upper layer, or at least an intersection where the power supply voltage line is an upper layer in the display unit 5. A region having a portion, at least a region having a crossing where a voltage supply to a wiring is longer in time than other wirings, and at least a voltage supply to the wiring in at least the display portion 5 is another wiring in time A region having a crossing portion in which a longer wiring is an upper layer, a region having a crossing portion in which wiring containing Al is included in at least one of the constituent materials, or a wiring containing Al in one of the constituent materials in at least the display portion 5 It may be performed in a region having an intersecting portion including.

  Next, a method for manufacturing the electrophoretic display device 100 will be described, and another effect of the uneven portion 80 will be described. 10A to 10C are diagrams illustrating an example of a manufacturing process of the electrophoretic display device 100. FIG. In FIG. 10, the structure of the element substrate 30 is simplified, and the pixel electrode 35 is not shown. In FIG. 10, the structure of the counter substrate 31 is simplified, and the counter electrode 37 is not shown.

  First, the element substrate 30 including the pixel electrode 35, the selection transistor 41, and various circuits is formed. The process of forming the element substrate 30 includes a step of forming the concavo-convex portion 80 (a concavo-convex forming step). The concavo-convex portion 80 is formed so that the concave portion 81 does not overlap the convex structure portion 95 in a plan view by adjusting an exposure amount or the like when the second interlayer insulating film 76 is formed by a photolithography method, for example. Is done. Alternatively, the concavo-convex portion 80 is a region in which a decrease due to the concave portion 81 from the uppermost surface of the second interlayer insulating film 76 is 10% or less of the thickness of the thickest portion of the second interlayer insulating film 76 in a plan view. The convex structure portion 95 is formed so as to overlap.

  Subsequently, an electrophoretic sheet 51 in a state where a protective release sheet is attached to the surface of the adhesive layer 50 is prepared. Then, as shown in FIG. 10A, the electrophoretic sheet 51 from which the release sheet has been peeled is bonded to the element substrate 30. The electrophoretic sheet 51 and the element substrate 30 are bonded together by pressing each other while being heated at a predetermined temperature.

  Here, when the electrophoretic sheet 51 is bonded, an air pocket (bubble) is generated between the adhesive layer 50 and the element substrate 30. When the electrophoretic sheet 51 is bonded to the element substrate 30 and the adhesive layer 50 comes into contact with the convex portion 82 of the concavo-convex portion 80, the bubbles 90 pushed out between the adhesive layer 50 and the convex portion 82 are shown in FIG. So as to flow into the recess 81.

  Further, when the electrophoretic sheet 51 is pressed, the adhesive layer 50 enters the recess 81. In the present embodiment, since the recess 81 is formed so as to communicate with the outside of the display unit 5, the bubbles 90 that have flowed into the recess 81 are reliably discharged to the external region. Finally, as shown in FIG. 10C, the electrophoretic element 32 and the element substrate 30 are bonded via the adhesive layer 50, whereby the element substrate 30 and the counter substrate 31 are joined. The display device 100 is manufactured.

  According to the present embodiment, the bubbles 90 generated when the electrophoretic sheet 51 is bonded to the element substrate 30 can be favorably discharged to the outside by being pushed out into the recess 81 by the protrusion 82. Accordingly, since the bubbles 90 are prevented from entering the adhesive layer 50, a decrease in adhesion due to the entry of the bubbles 90 is prevented.

  Further, the convex structure portion 95 is arranged in a region where the decrease due to the concave portion 81 from the uppermost surface of the second interlayer insulating film 76 is 10% or less of the thickness of the thickest portion, or the convex structure portion 95 is uneven. Since it does not overlap with the concave portion 81 of the portion 80, the film thickness of the second interlayer insulating film 76 can be sufficiently secured even when the concave-convex portion 80 is formed. Therefore, the highly reliable electrophoretic display device 100 having good display quality can be manufactured by being excellent in insulation.

According to the configuration of the present embodiment, bubbles generated when the display sheet is bonded to the circuit board are discharged to the outside along the recesses of the concavo-convex portion, so that the entry of bubbles into the adhesive layer is prevented, and the bubbles Decrease in adhesion due to the penetration of is prevented. Therefore, the adhesiveness in an adhesive layer and an uneven | corrugated | grooved part improves more, and a display sheet will be favorably bonded to a circuit board through the adhesive layer.
Furthermore, since the convex structure portion is formed so as to overlap the convex portion, the film thickness of the coating film is sufficiently ensured even when the concave and convex portion is formed. Therefore, a highly reliable display device having excellent display quality due to excellent insulation is provided.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the electrophoretic display device 100 in which the element substrate 30 and the electrophoretic sheet 51 are bonded to each other is described as an example of the display device, but the present invention is not limited to this. That is, the present invention may be applied to, for example, a liquid crystal display device or an organic electroluminescence device in which the display sheet bonded via the adhesive layer includes a liquid crystal layer or an organic electroluminescence element.

  H: thickness, 30: element substrate (circuit board), 35: pixel electrode, 36: scanning line, 37: counter electrode, 38 ... data line, 50 ... adhesive layer, 51 ... electrophoresis sheet (display sheet), 72 DESCRIPTION OF SYMBOLS ... Semiconductor layer, 76 ... 2nd interlayer insulation film (coating film), 80 ... Uneven part, 81 ... Concave part, 82 ... Convex part, 90 ... Convex structure part, 100 ... Electrophoretic display device.

Claims (10)

In a display device in which a circuit board including a pixel circuit in which a pixel electrode is formed and a display sheet including a counter electrode capable of applying a voltage between the pixel electrode are bonded together via an adhesive layer,
The circuit board includes a convex structure part, and a coating film covering the convex structure part,
The coating film has a concave and convex portion including a concave portion and a convex portion on the bonding surface with the adhesive layer,
The display device, wherein the convex structure portion is formed to overlap the convex portion.   In the state where the uneven portion is seen in a plan view, the convex structure portion is formed in a region where a decrease due to the concave portion from the uppermost surface of the coating film is 10% or less of the thickness of the thickest portion of the coating film. A display device characterized by being formed to overlap each other. In a display device in which a circuit board including a pixel circuit in which a pixel electrode is formed and a display sheet including a counter electrode capable of applying a voltage between the pixel electrode are bonded together via an adhesive layer,
The circuit board includes a convex structure part, and a coating film covering the convex structure part,
The coating film is formed with a concave and convex portion including a concave portion and a concave portion on the bonding surface with the adhesive layer,
The display device according to claim 1, wherein the concave-convex portion is formed so that the concave portion does not overlap the convex structure portion in a plan view. The circuit board includes a semiconductor layer, a scanning line, and a data line,
The display device according to claim 1, wherein the convex structure portion is configured by overlapping at least two of the semiconductor layer, the scanning line, and the data line in a plan view. The display device according to any one of claims 1 to 4, wherein the display sheet is an electrophoretic sheet. A pixel circuit on which a pixel electrode is formed, a convex structure portion, a circuit substrate including a coating film covering the convex structure portion, and a display sheet including a counter electrode capable of applying a voltage between the pixel electrodes, In the manufacturing method of the display device bonded through the adhesive layer,
The step of forming the circuit board includes a concavo-convex forming step of forming a concavo-convex portion including a concave portion and a convex portion on the bonding surface with the adhesive layer,
In the method of manufacturing a display device, the unevenness forming step includes forming the unevenness portion so that the convex structure portion and the convex portion overlap each other.   In the planar view, the step of forming the irregularities includes the circuit board in a region where a decrease due to the concave portion from the uppermost surface of the coating film is 10% or less of the thickness of the thickest portion of the coating film. The method for manufacturing a display device according to claim 6, wherein the concavo-convex portion is formed so that the convex structure portions of the pits overlap. A pixel circuit on which a pixel electrode is formed, a convex structure portion, a circuit substrate including a coating film covering the convex structure portion, and a display sheet including a counter electrode capable of applying a voltage between the pixel electrodes, In the manufacturing method of the display device bonded through the adhesive layer,
The step of forming the circuit board includes a concavo-convex forming step of forming a concavo-convex portion including a concave portion and a convex portion on the bonding surface with the adhesive layer,
The manufacturing method of a display device, wherein the unevenness forming step forms the unevenness portion so that the recess does not overlap the convex structure portion in a plan view. The circuit board includes a semiconductor layer, a scanning line, and a data line,
The display device according to claim 6, wherein the convex structure portion is configured by overlapping at least two of the semiconductor layer, the scanning line, and the data line in a plan view. Production method.   The method for manufacturing a display device according to claim 6, wherein an electrophoretic sheet is used as the display sheet.

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