Display device

Abstract

A display device provided with: a glass substrate in which a first wiring pattern is provided on a first principal surface and a second wiring pattern is provided on a second principal surface that is opposite the first principal surface; a through hole including a tapered opening having an opening diameter that gradually expands going toward the first principal surface, the tapered opening being provided in the vicinity of the first principal surface, and a penetration part extending from the tapered opening in the thickness direction of the glass substrate, the through-hole penetrating the glass substrate; and a connection part provided inside of the through-hole, the connection part electrically connecting the first and the second wiring patterns.

Description

[Technical field]

[0001] The present disclosure relates to a display device. [Background technology]

[0002] In recent years, electronic devices have become more and more sophisticated, and various developments are being made to achieve this. For example, a technology has been developed in which a functional element provided on one side of a substrate is electrically connected to wiring provided on the other side of the substrate by a through electrode that penetrates the substrate (for example, Patent Document 1).

[0003] Meanwhile, various display devices have been proposed, such as liquid crystal displays, OLED (Organic Light Emitting Diode) displays, micro LED (Light Emitting Diode) displays, etc. In these display devices, a glass substrate is generally used as a substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2016-63114 A Summary of the Invention

[0005] In such a glass substrate, it is desirable to provide the substrate with fewer scratches or stresses in order to maintain the strength of the glass substrate. Therefore, it is desirable to provide a through-glass via (TGV) penetrating the glass substrate in such a manner that the substrate is less scratched or stressed, thereby maintaining the strength of the glass substrate.

[0006] It is therefore desirable to provide a stronger and more reliable display device.

[0007] A display device according to one embodiment of the present disclosure includes a glass substrate having a first wiring pattern on a first main surface and a second wiring pattern on a second main surface opposite the first main surface, a through hole penetrating the glass substrate, the through hole including a tapered opening provided near the first main surface and having an opening diameter increasing toward the first main surface and a penetration portion extending from the tapered opening in a thickness direction of the glass substrate, and a connection portion provided inside the through hole and electrically connecting the first wiring pattern and the second wiring pattern.

[0008] According to an embodiment of the display device of the present disclosure, a glass substrate having a first wiring pattern on a first main surface and a second wiring pattern on a second main surface opposite to the first main surface, a through hole penetrating the glass substrate, and a connection portion provided inside the through hole and electrically connecting the first wiring pattern and the second wiring pattern, the through hole being provided near the first main surface and including a tapered opening whose opening diameter increases toward the first main surface, and a through portion extending from the tapered opening in the thickness direction of the glass substrate. As a result, for example, the display device according to the present embodiment can suppress the occurrence of scratches or stress on the glass substrate. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view illustrating a schematic overall configuration of a display device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a perspective view that illustrates a schematic example of a tiling display using the display device illustrated in FIG. [Diagram 3] 4 is a vertical cross-sectional view illustrating a configuration of a through electrode provided in the display device according to the embodiment. FIG. [Figure 4A] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4B] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4C]5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4D] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4E] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4F] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4G] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4H] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4I] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4J] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 4K] 5A to 5C are vertical cross-sectional views illustrating steps of a first manufacturing method for a through electrode provided in the display device according to the embodiment. [Figure 5A] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5B] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5C] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5D] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5E] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5F] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5G] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5H] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5I] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 5J] 5A to 5C are vertical cross-sectional views illustrating steps of a second manufacturing method for a through electrode provided in the display device according to the same embodiment. [Figure 6] 13 is a vertical cross-sectional view illustrating a configuration of a through electrode provided in a display device according to a modified example of the embodiment. FIG. [Figure 7] FIG. 2 is a schematic diagram showing the appearance of a television device to which the display device according to the embodiment is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the drawings. The embodiment described below is a specific example of the present disclosure, and the technology according to the present disclosure is not limited to the following aspects. Furthermore, the arrangement, dimensions, and dimensional ratios of each component of the present disclosure are not limited to the aspects shown in each drawing.

[0011] The explanation will be given in the following order. 1. Embodiment 1.1.Outline of the display device 1.2.Structure of the through electrode 1.3. Manufacturing method 1.4. Variations 2. Application Examples

[0012] <1. Embodiment> (1.1. Schematic configuration of the display device) First, a schematic configuration of a display device according to an embodiment of the present disclosure will be described with reference to Figures 1 and 2. Figure 1 is a perspective view that illustrates a schematic overall configuration of the display device according to the present embodiment.

[0013] 1, the display device 1 according to this embodiment includes, for example, a counter substrate 1A, an array substrate 1B, and a control substrate 1C. The display device 1 according to this embodiment may be a liquid crystal display having a liquid crystal layer (not shown) provided between the counter substrate 1A and the array substrate 1B that face each other. The image display surface of the display device 1 is the surface of the counter substrate 1A opposite to the surface facing the array substrate 1B.

[0014] The counter substrate 1A is composed of a transparent substrate such as a glass substrate that transmits light in the visible light range. The counter substrate 1A has red, green, and blue color filters and a black matrix on the surface facing the array substrate 1B, and a common electrode made of a transparent conductive material that spreads over the entire surface of the counter substrate 1A on the surface facing the array substrate 1B.

[0015] The array substrate 1B is made of a transparent substrate such as a glass substrate that transmits light in the visible light band. The array substrate 1B has active elements such as TFTs (Thin Film Transistors) and pixel electrodes provided for each pixel on the surface facing the counter substrate 1A.

[0016] The control substrate 1C includes a control circuit for controlling display or non-display of each pixel provided on the array substrate 1B, etc. For example, the control substrate 1C may include a control circuit for supplying image signals, driving power, etc. to the array substrate 1B.

[0017] As a result, the display device 1 can control the polarization direction of light passing through the liquid crystal layer for each pixel by controlling the voltage applied to the liquid crystal layer by the common electrode and pixel electrode provided on the counter substrate 1A and the array substrate 1B. Therefore, by providing two polarizing plates whose polarization directions are perpendicular to each other so as to sandwich the counter substrate 1A and the array substrate 1B, the display device 1 can control the transmission or non-transmission of light through the polarizing plate, array substrate 1B, liquid crystal layer, counter substrate 1A, and polarizing plate for each pixel. Therefore, the display device 1 can control the display or non-display of each pixel.

[0018] On the other hand, in the display device 1, the control substrate 1C is laminated on the surface of the array substrate 1B opposite to the surface facing the counter substrate 1A. Therefore, in the array substrate 1B, it is desired to form a conductive path from the surface facing the counter substrate 1A to the surface opposite to the facing surface. As such a conductive path, for example, a through electrode penetrating from one main surface of the array substrate 1B to the other main surface can be considered. The through electrode can electrically connect the wiring provided on one main surface of the array substrate 1B to the wiring provided on the other main surface over a short distance, so that signal loss or delay due to wiring can be suppressed.

[0019] Furthermore, the through wiring can function more effectively in a tiling display as shown in Fig. 2. Fig. 2 is a perspective view that shows a schematic example of a tiling display using the display device 1 shown in Fig. 1. Note that, although Fig. 2 shows an example in which the large-screen display device 2 is configured with nine display devices 1, the number of display devices 1 that configure the large-screen display device 2 is not limited to this example. For example, the large-screen display device 2 may be configured with eight or less or ten or more display devices 1.

[0020] As shown in FIG. 2, a large-screen display device 2 may be constructed by, for example, arranging a plurality of display devices 1 shown in FIG. 1 in a tiled manner. A large-screen display device 2 using a plurality of display devices 1 is also called a tiling display. In such a large-screen display device 2, the display devices 1 may be arranged with close spacing in the lateral direction so that the seams between the tiled display devices 1 are not visible. Also, it is desirable that the control circuit and the like of the display device 1 be provided on the control substrate 1C rather than the array substrate 1B in order to enlarge the pixel area of ​​the display device 1.

[0021] That is, when the display device 1 is used as a unit of a tiling display, it is difficult to arrange the control substrate 1C on the side of the display device 1 in terms of the width of the interval in the lateral direction of the display device 1. Therefore, it is important that the conductive path from one main surface to the other main surface of the array substrate 1B is formed as a through electrode penetrating the array substrate 1B. Also, in order to prevent the user from noticing the seams between the display devices 1, it is desirable that the control circuit of the display device 1 is provided separately on the control substrate 1C, not on the periphery of the pixel region of the array substrate 1B.

[0022] However, in the process of providing the through electrodes in the array substrate 1B, scratches or stress may occur in the array substrate 1B. In particular, when the array substrate 1B is a glass substrate, scratches or stress occurring in the glass substrate may significantly reduce the strength of the array substrate 1B. Therefore, in order to maintain the strength of the array substrate 1B, it is desirable that the through electrodes penetrating the array substrate 1B are formed while suppressing the occurrence of scratches or stress in the array substrate 1B.

[0023] In view of the above circumstances, the present inventors have come up with the technology according to the present disclosure, in which a through hole is provided through a glass substrate to provide a through electrode, the through hole having a tapered opening having an inverse tapered shape and a through portion extending substantially perpendicularly from the tapered opening.

[0024] According to the technology of the present disclosure, it is possible to prevent scratches or stress on the glass substrate caused by forming through holes, and therefore it is possible to provide through electrodes on the glass substrate while maintaining its strength. Therefore, in the display device 1, for example, the counter substrate 1A, the array substrate 1B, and the control substrate 1C can be electrically connected to each other by the through electrodes while maintaining the strength of each substrate. Therefore, according to the technology of the present disclosure, it is possible to provide a display device that maintains its strength.

[0025] (1.2. Structure of the Through Electrode) Next, a specific configuration of the through electrode provided in the display device 1 according to this embodiment will be described with reference to Fig. 3. Fig. 3 is a vertical cross-sectional view illustrating the configuration of the through electrode provided in the display device 1 according to this embodiment. Fig. 3 shows only the peripheral configuration of the through electrode of the display device 1.

[0026] As shown in FIG. 3, the display device 1 comprises a glass substrate 100, a through hole 110 including a tapered opening 110A and a through portion 110B, which passes through the glass substrate 100, and a connection portion 120 provided on the inner side surface of the through hole 110.

[0027] The glass substrate 100 is a substrate corresponding to the array substrate 1B of the display device 1. The glass substrate 100 may be, for example, a quartz glass substrate, an aluminosilicate glass substrate, or a soda-lime glass substrate.

[0028] Further, a first wiring pattern 131 and an interlayer film 132 covering the first wiring pattern 131 are provided on the flat first main surface S1 of the glass substrate 100. The first wiring pattern 131 and the interlayer film 132 may be provided in a plurality of layers by being alternately laminated.

[0029] The first wiring pattern 131 is, for example, a wiring electrically connected to a pixel electrode provided for each pixel on the array substrate 1B. The first wiring pattern 131 may be made of a metal used for general wiring or electrodes. For example, the first wiring pattern 131 may be made of Cu (copper), Ti (titanium), Mo (molybdenum), Al (aluminum), or the like.

[0030] The interlayer film 132 is a film that electrically insulates each layer of the multi-layered first wiring pattern 131. The interlayer film 132 can be made of an organic insulating material or an inorganic insulating material. For example, the interlayer film 132 can be made of an organic resin such as an acrylic resin or a novolac resin, or an SiO 2 Alternatively, it may be made of an inorganic oxynitride such as SiN.

[0031] The interlayer film 132 has an opening 135 for forming the through hole 110 in the glass substrate 100. For example, the interlayer film 132 may be provided on the first main surface S1 so that the region in which the through hole 110 is to be formed in a later step is exposed at the opening 135. That is, the opening size of the opening 135 provided in the interlayer film 132 is larger than the opening of the tapered opening 110A of the through hole 110.

[0032] On the other hand, on a flat second main surface S2 of the glass substrate 100 opposite to the first main surface S1, a second wiring pattern 141 and an insulating film 142 covering the second wiring pattern 141 are provided.

[0033] The second wiring pattern 141 forms an electrical connection point with the control substrate 1C on the second main surface S2. Specifically, bumps or the like (not shown) are provided on the second wiring pattern 141 exposed from the insulating film 142, and electrical connection between the array substrate 1B and the control substrate 1C is formed via the bumps or solder or the like. The second wiring pattern 141 may be provided in a laminated structure of a seed layer containing Cu (copper) or Ti (titanium) and a plating layer containing Cu (copper), for example, by using an electrolytic plating method.

[0034] The insulating film 142 is provided so as to cover a portion of the second wiring pattern 141 and expose a portion of the second wiring pattern 141. The insulating film 142 is provided to form an electrical contact of the second wiring pattern 141 in a predetermined region of the second main surface S2 while protecting the second wiring pattern 141. The insulating film 142 may be made of, for example, an organic resin having insulating properties. For example, the insulating film 142 may be made of a filler-containing resist, a solder resist, or the like.

[0035] The through holes 110 are provided penetrating the glass substrate 100. As described later, an electrical connection between a first wiring pattern 131 provided on the first main surface S1 and a second wiring pattern 141 provided on the second main surface S2 is formed at a connection portion 120 provided via the through holes 110.

[0036] Specifically, the through hole 110 is composed of a tapered opening 110A provided in the vicinity of the first main surface S1, and a through portion 110B provided extending in the thickness direction of the glass substrate 100 from the tapered opening 110A.

[0037] The tapered opening 110A is provided so that the opening diameter becomes larger toward the first main surface S1. That is, the tapered opening 110A is provided so as to have a so-called inverse tapered shape when the first main surface S1 is the upper side and the second main surface S2 is the lower side. By providing the tapered opening 110A, the angle of the inner side surface of the through hole 110 is changed stepwise from the flat first main surface S1 in a direction substantially perpendicular to the first main surface S1.

[0038] The through portion 110B extends from the end of the inverse tapered shape of the tapered opening 110A approximately perpendicularly to the thickness direction of the glass substrate 100 until it reaches the second main surface S2. The through portion 110B may be provided in a columnar shape, or may be provided in a similar inverse tapered shape to the tapered opening 110A. However, the through portion 110B is provided so that the degree of taper is at least smaller than that of the tapered opening 110A.

[0039] The connection portion 120 is provided on the inner side surface of the through hole 110, and electrically connects the first wiring pattern 131 and the second wiring pattern 141. Specifically, the connection portion 120 is provided so as to cover the entire inner side surface of the through portion 110B, the tapered opening 110A, and the opening 135 of the interlayer film 132. As a result, the connection portion 120 is provided up to the interlayer film 132 on the first main surface S1, and can be electrically connected to the first wiring pattern 131 through the via 121 penetrating the interlayer film 132. Furthermore, the connection portion 120 is provided continuously with the second wiring pattern 141 on the second main surface S2, and can be electrically connected to the second wiring pattern 141. Therefore, the connection portion 120 is formed conformally on the inner side surface of the through hole 110, and can electrically connect the first wiring pattern 131 and the second wiring pattern 141.

[0040] The connection part 120 may be formed by, for example, electrolytic plating. In such a case, the connection part 120 is provided in a laminated structure of a seed layer 120B containing Cu (copper) or Ti (titanium) and a plating layer 120A containing Cu (copper). By using electrolytic plating, the connection part 120 can be more reliably formed along the complex shape of the inside of the through hole 110.

[0041] The space inside the through hole 110 may be filled with a filling material 150 containing, for example, an insulating material or a metallic material.

[0042] When the embedding material 150 is made of an insulating material, the embedding material 150 may be, for example, an insulating organic resin such as an acrylic resin or a novolac resin. The embedding material 150 may further include a filler or the like to adjust various parameters such as strength, viscosity, or dielectric constant.

[0043] When the embedding material 150 is made of a metal material, the embedding material 150 may be a metal such as Cu (copper), Ti (titanium), Mo (molybdenum), or Al (aluminum). In such a case, the embedding material 150 can more reliably form a conductive path between the first wiring pattern 131 and the second wiring pattern 141.

[0044] According to the above configuration, the through hole 110 is provided to include the tapered opening 110A and the through portion 110B, thereby preventing the connection portion 120 formed on the inner side surface of the through hole 110 from being bent at an acute angle for wiring. Therefore, the display device 1 can reduce the stress on the glass substrate 100 caused by the connection portion 120.

[0045] Furthermore, in the display device 1, the through portion 110B can easily penetrate the glass substrate 100 without excessively increasing the opening diameter of the tapered opening portion 110A in the first main surface S1. Therefore, the display device 1 can more easily electrically connect the first wiring pattern 131 provided on the first main surface S1 and the second wiring pattern 141 provided on the second main surface S2.

[0046] Furthermore, in the display device 1, the first wiring pattern 131 and the connection portion 120 can be formed separately, so that it becomes easier to form desired patterns for each of them. Specifically, the through hole 110 and the connection portion 120 can be made to have a pattern size for ensuring reliable conduction between the first wiring pattern 131 and the second wiring pattern 141, while the first wiring pattern 131 can be made to have a finer pattern size. Accordingly, the first wiring pattern 131 can be formed to include a wiring pattern that is thinner than the minimum opening diameter of the through hole 110, for example.

[0047] (1.3. Manufacturing method) (First manufacturing method) Next, a first manufacturing method for the through electrode provided in the display device 1 according to this embodiment will be described with reference to Fig. 4A to Fig. 4K. Fig. 4A to Fig. 4K are vertical cross-sectional views illustrating each step of the first manufacturing method for the through electrode provided in the display device 1 according to this embodiment. Fig. 4A to Fig. 4K show only the peripheral configuration of the through electrode of the display device 1.

[0048] First, as shown in FIG. 4A, a first wiring pattern 131 and an interlayer film 132 are alternately laminated on a first main surface S1 of a glass substrate 100. An opening 135 is provided in the interlayer film 132 to expose the glass substrate 100 in order to form a through hole 110 in the glass substrate 100 in a later step. The opening 135 is provided, for example, to have a larger opening diameter than the maximum opening diameter of a tapered opening 110A of the through hole 110 formed in a later step. Furthermore, a via opening 121A is provided in the interlayer film 132 to expose the first wiring pattern 131 in order to form a via 121 that electrically connects the connection portion 120 and the first wiring pattern 131 in a later step. The first wiring pattern 131 may be formed of, for example, Cu (copper), Ti (titanium), Mo (molybdenum), Al (aluminum), or the like. The interlayer film 132 is formed of, for example, SiO 2 (silicon dioxide) or SiN (silicon nitride), or the like.

[0049] 4B, a resist layer 171 is formed over the entire surface of the first main surface S1 of the glass substrate 100 so as to cover the interlayer film 132. The resist layer 171 is provided to protect regions other than the regions where the through holes 110 are formed when the glass substrate 100 is wet-etched in a later process. The resist layer 171 is made of, for example, a resist material that is resistant to an etching solution for the glass substrate 100 (for example, a hydrofluoric acid-based etching solution).

[0050] Next, as shown in FIG. 4C, a UV laser or CO 2 Through holes 110 penetrating the resist layer 171 and the glass substrate 100 are formed by laser processing using a laser.

[0051] 4D, the glass substrate 100 is wet-etched with a hydrofluoric acid-based etching solution through the through-hole 110 formed in the resist layer 171, thereby forming a tapered opening 110A and a through-hole 110B in the glass substrate 100. As a result, the inner side surface of the through-hole 110 is smoothed by the wet etching, and minute scratches and the like formed on the glass substrate 100 by the laser processing are erased. Therefore, the glass substrate 100 can maintain its strength even after the through-hole 110 is formed.

[0052] Specifically, the vicinity of the first main surface S1 of the glass substrate 100 is isotropically etched by the etching liquid that has penetrated into the interface between the glass substrate 100 and the resist layer 171, thereby forming a tapered opening 110A whose opening diameter increases toward the first main surface S1. Also, the inner side surface of the through hole 110 formed in the glass substrate 100 by laser processing is uniformly wet-etched, thereby forming a through portion 110B.

[0053] Next, as shown in FIG. 4E, the resist layer 171 is removed.

[0054] 4F, a sputtering method is used to uniformly deposit Ti (titanium) on the first main surface S1, the second main surface S2, and the inside of the through-hole 110 of the glass substrate 100, thereby forming a seed layer 120B. That is, Ti (titanium) is uniformly deposited on the first main surface S1, the second main surface S2, and all of the exposed surfaces of the through-hole 110 of the glass substrate 100, thereby forming the seed layer 120B.

[0055] 4G, a resist layer 172 is formed on each of the first main surface S1 and the second main surface S2 in an area excluding the area where the connection portion 120 and the second wiring pattern 141 are to be formed. The resist layer 172 is provided to protect the area other than the area where the connection portion 120 and the second wiring pattern 141 are to be formed when the connection portion 120 and the second wiring pattern 141 are to be formed by electrolytic plating in a later step. The resist layer 172 is made of, for example, a resist material that is resistant to a plating solution of Cu (copper).

[0056] 4H, electrolytic plating is used to form a plating layer 120A on the seed layer 120B in an area not protected by the resist layer 172. This forms the connection portion 120 and the second wiring pattern 141 in a desired area. Furthermore, the seed layer 120B and the plating layer 120A are conformally formed inside the via opening 121A, so that the connection portion 120 and the first wiring pattern 131 are electrically connected to each other.

[0057] Then, as shown in FIG. 4I, the resist layer 172 is removed.

[0058] 4J, the seed layer 120B that is not covered by the plating layer 120A and is exposed on each of the first main surface S1 and the second main surface S2 is removed by etching. The etching of the seed layer 120B can be performed by utilizing the etching selectivity due to the materials of the plating layer 120A formed of Cu (copper) and the seed layer 120B formed of Ti (titanium), for example.

[0059] Next, as shown in Fig. 4K, the space inside the through hole 110 is filled with a filling material 150 made of an insulating material such as an acrylic resin or a novolac resin. A partial region of the second main surface S2 of the glass substrate 100 is covered with an insulating film 142. Specifically, the insulating film 142 is formed by applying a solder resist or the like to a partial region on the second main surface S2 of the glass substrate 100. As a result, a partial region of the second wiring pattern 141 is covered with the insulating film 142 and a partial region is exposed.

[0060] According to the above steps, a through electrode is formed which penetrates the glass substrate 100 and electrically connects the first wiring pattern 131 provided on the first main surface S1 and the second wiring pattern 141 provided on the second main surface S2.

[0061] According to the above manufacturing method, the through electrode can be formed without performing a step of flattening each layer provided on the glass substrate 100 by polishing. For example, when the through electrode is formed by filling the through hole 110 by via-filling, a step of removing the plating layer formed in excess of the through electrode and flattening the first main surface S1 of the glass substrate 100 is required. However, polishing the glass substrate 100 may cause fine scratches on the surface of the glass substrate 100, which may significantly reduce the strength of the glass substrate 100. According to the above manufacturing method, the through electrode can be formed without polishing the first main surface S1 of the glass substrate 100, so that the strength of the glass substrate 100 can be maintained.

[0062] (Second manufacturing method) Next, a second manufacturing method for the through electrode provided in the display device 1 according to this embodiment will be described with reference to Fig. 5A to Fig. 5J. Fig. 5A to Fig. 5J are vertical cross-sectional views illustrating each step of the second manufacturing method for the through electrode provided in the display device 1 according to this embodiment. Fig. 5A to Fig. 5J show only the peripheral configuration of the through electrode of the display device 1.

[0063] The second manufacturing method is different from the first manufacturing method in that the connection portion 120 is formed only by a sputtering method, not by an electrolytic plating method. Therefore, in the second manufacturing method, the connection portion 120 is provided as a single layer film of a metal such as Cu (copper).

[0064] First, as shown in FIG. 5A, a first wiring pattern 131 and an interlayer film 132 are alternately laminated on a first main surface S1 of a glass substrate 100. An opening 135 is provided in the interlayer film 132 to expose the glass substrate 100 in order to form a through hole 110 in the glass substrate 100 in a later step. The opening 135 is provided, for example, to have a larger opening diameter than the maximum opening diameter of a tapered opening 110A of the through hole 110 formed in a later step. Furthermore, a via opening 121A is provided in the interlayer film 132 to expose the first wiring pattern 131 in order to form a via 121 that electrically connects the connection portion 120 and the first wiring pattern 131 in a later step. The first wiring pattern 131 may be formed of, for example, Cu (copper), Ti (titanium), Mo (molybdenum), or Al (aluminum). The interlayer film 132 is formed of, for example, SiO 2 (silicon dioxide) or SiN (silicon nitride), or the like.

[0065] 5B, a resist layer 171 is formed over the entire surface of the first main surface S1 of the glass substrate 100 so as to cover the interlayer film 132. The resist layer 171 is provided to protect regions other than the regions where the through holes 110 are formed when the glass substrate 100 is wet-etched in a later process. The resist layer 171 is made of, for example, a resist material that is resistant to an etching solution for the glass substrate 100 (for example, a hydrofluoric acid-based etching solution).

[0066] Next, as shown in FIG. 5C, a UV laser or CO 2 Through holes 110 penetrating the resist layer 171 and the glass substrate 100 are formed by laser processing using a laser.

[0067] 5D, the glass substrate 100 is wet-etched with a hydrofluoric acid-based etching solution through the through-hole 110 formed in the resist layer 171, thereby forming a tapered opening 110A and a through-hole 110B in the glass substrate 100. As a result, the inner side surface of the through-hole 110 is smoothed by the wet etching, and minute scratches and the like formed on the glass substrate 100 by the laser processing are erased. Therefore, the glass substrate 100 can maintain its strength even after the through-hole 110 is formed.

[0068] Specifically, the vicinity of the first main surface S1 of the glass substrate 100 is isotropically etched by the etching liquid that has penetrated into the interface between the glass substrate 100 and the resist layer 171, thereby forming a tapered opening 110A whose opening diameter increases toward the first main surface S1. Also, the inner side surface of the through hole 110 formed in the glass substrate 100 by laser processing is uniformly wet-etched, thereby forming a through portion 110B.

[0069] Next, as shown in FIG. 5E, the resist layer 171 is removed.

[0070] 5F, a sputtering method is used to uniformly form a Cu (copper) film on the first main surface S1, the second main surface S2 of the glass substrate 100, and the inside of the through hole 110, thereby forming the connection portion 120. That is, a Cu (copper) film is uniformly formed on the first main surface S1, the second main surface S2 of the glass substrate 100, and all of the exposed surfaces of the through hole 110, thereby forming the connection portion 120.

[0071] 5G, a resist layer 173 is formed on each of the first main surface S1 and the second main surface S2 in an area where the connection portion 120 and the second wiring pattern 141 are to be formed. The resist layer 173 is provided to remove the connection portion 120 and the second wiring pattern 141 formed in areas other than the desired area. The resist layer 173 is made of, for example, a resist material that is resistant to etching with Cu (copper).

[0072] 5H, the connection portion 120 and the second wiring pattern 141 that are not covered with the resist layer 173 and are exposed on each of the first main surface S1 and the second main surface S2 are removed by etching. As a result, the connection portion 120 and the second wiring pattern 141 are formed in desired regions. In addition, the connection portion 120 is conformally formed inside the via opening 121A, so that the connection portion 120 and the first wiring pattern 131 are electrically connected to each other.

[0073] Then, as shown in FIG. 5I, the resist layer 173 is removed.

[0074] 5J, the space inside the through hole 110 is filled with a filling material 150 made of an insulating material such as an acrylic resin or a novolac resin. A partial region of the second main surface S2 of the glass substrate 100 is covered with an insulating film 142. Specifically, the insulating film 142 is formed by applying a solder resist or the like to a partial region on the second main surface S2 of the glass substrate 100. As a result, a partial region of the second wiring pattern 141 is covered with the insulating film 142 and a partial region is exposed.

[0075] According to the above steps, a through electrode is formed which penetrates the glass substrate 100 and electrically connects the first wiring pattern 131 provided on the first main surface S1 and the second wiring pattern 141 provided on the second main surface S2.

[0076] According to the above manufacturing method, similarly to the first manufacturing method, the through electrodes can be formed without performing a step of planarizing each layer provided on the glass substrate 100 by polishing. Therefore, according to the second manufacturing method, the through electrodes can be formed without polishing the first main surface S1 of the glass substrate 100, so that the strength of the glass substrate 100 can be maintained.

[0077] Furthermore, according to the second manufacturing method, the connection portion 120 and the second wiring pattern 141 can be formed without performing an electrolytic plating process, so that the manufacturing process can be further simplified.

[0078] (1.4. Modifications) Furthermore, a modified example of the display device 1 according to the present embodiment will be described with reference to Fig. 6. Fig. 6 is a vertical cross-sectional view illustrating the configuration of a through electrode provided in a display device 10 according to the modified example. Fig. 6 shows only the peripheral configuration of the through electrode of the display device 10.

[0079] 1 in that the first wiring pattern 131 and the connection portion 120 are directly and electrically connected to each other without the via 121 penetrating the interlayer film 132. Note that other configurations of the display device 10 according to the modification are substantially similar to those of the display device 1 shown in FIG. 1, and therefore a description thereof will be omitted here.

[0080] 6, the first wiring pattern 131 is provided such that its end protrudes from the interlayer film 132. The protruding end of the first wiring pattern 131 can be electrically connected to the opening 135 of the interlayer film 132 and the connection portion 120 provided along the inner side surface of the through hole 110 inside the opening 135 of the interlayer film 132. As a result, the first wiring pattern 131 can be directly electrically connected to the connection portion 120, and therefore the reliability of signal transmission between the first wiring pattern 131 and the second wiring pattern 141 can be further improved.

[0081] 6, the first wiring pattern 131 is provided on the first main surface S1 of the glass substrate 100, but the position of the first wiring pattern 131 is not limited to this example. For example, the first wiring pattern 131 may be provided so as to be sandwiched between two interlayer films 132 laminated on the first main surface S1 of the glass substrate 100. Even in such a case, the first wiring pattern 131 can be electrically connected to the connection portion 120 by being provided so as to protrude from the interlayer film 132.

[0082] <2. Application Examples> The display device 1 according to the present embodiment can be applied to various electronic devices that display an image signal input from the outside or an image signal generated inside. For example, the display device 1 according to the present embodiment can be applied to a television device, a digital camera, a notebook personal computer, a mobile phone, a smartphone, and the like. An example of an application example of the display device 1 according to the present embodiment is shown with reference to FIG. 7. FIG. 7 is a schematic diagram showing the appearance of a television device to which the display device 1 according to the present embodiment is applied.

[0083] 7, a television device 300 has an image display unit 310 including, for example, a front panel 320 and a filter glass 330. The display device 1 according to the present embodiment may be applied to such an image display unit 310.

[0084] The technology according to the present disclosure has been described above by giving embodiments and modifications. However, the technology according to the present disclosure is not limited to the above embodiments, and various modifications are possible.

[0085] For example, the display device 1 according to the present embodiment is not limited to a liquid crystal display, and may be applied to other displays provided on a glass substrate. Specifically, the display device 1 according to the present embodiment may be applied to a plasma panel display, an OLED display, a micro LED display, or the like.

[0086] In addition, not all of the configurations and operations described in the embodiments are necessarily essential to the configurations and operations of the present disclosure. For example, among the components in the embodiments, components that are not described in the independent claims showing the highest concept of the present disclosure should be understood as optional components.

[0087] Terms used throughout this specification and the appended claims should be construed as "open-ended" terms. For example, the terms "including" or "including" should be construed as "not limited to the manner in which it is described as including." The term "having" should be construed as "not limited to the manner in which it is described as having."

[0088] The terms used in this specification include terms that are used merely for convenience of explanation and are not used for the purpose of limiting the configuration and operation. For example, terms such as "right", "left", "upper", and "lower" merely indicate directions on the drawings to which reference is made. Furthermore, the terms "inner" and "outer" merely indicate directions toward and away from the center of the focused element, respectively. The same applies to terms similar to these and terms of a similar meaning.

[0089] The technology according to the present disclosure may also have the following configuration. According to the technology according to the present disclosure having the following configuration, the through hole penetrating the glass substrate is configured to include a tapered opening and a through portion, thereby making it possible to suppress the occurrence of scratches or stress on the glass substrate. Therefore, according to the technology according to the present disclosure, the strength of the glass substrate can be maintained, and therefore a display device with higher strength and reliability can be provided. The effects achieved by the technology according to the present disclosure are not necessarily limited to the effects described herein, and may be any of the effects described in the present disclosure. (1) a glass substrate having a first wiring pattern provided on a first main surface and a second wiring pattern provided on a second main surface opposite to the first main surface; a through hole penetrating the glass substrate, the through hole including a tapered opening provided near the first main surface and having an opening diameter increasing toward the first main surface, and a through portion extending from the tapered opening in a thickness direction of the glass substrate; a connection portion provided inside the through hole and electrically connecting the first wiring pattern and the second wiring pattern; A display device comprising: (2) The display device according to (1) above, wherein the first wiring pattern includes a wiring pattern that is narrower than a minimum inner diameter of an opening of the through hole. (3) The display device according to (1) or (2), wherein the connection portion is provided so as to cover an entire periphery of an inner side surface of the through hole with a conductive material. (4) The display device according to any one of (1) to (3) above, wherein a space inside the through hole is filled with an insulating material or a metallic material. (5) The display device according to any one of (1) to (4) above, wherein an interlayer film covering the first wiring pattern is further provided on the first main surface of the glass substrate. (6) The display device according to (5) above, wherein the connection portion is electrically connected to the first wiring pattern through a via that penetrates the interlayer film. (7) The display device according to (5) or (6), wherein the interlayer film has an opening having a diameter larger than a maximum opening diameter of the tapered opening in a region corresponding to the through hole. (8) the second main surface of the glass substrate is covered with an insulating film; The display device according to any one of (1) to (7) above, wherein the second wiring pattern is provided so as to be partially exposed from the insulating film. (9) The display device according to any one of (1) to (8) above, wherein the first main surface and the second main surface of the glass substrate are flat in areas other than the areas where the through holes are provided. (10) The display device according to any one of (1) to (9) above, which is a liquid crystal display device. (11) The display device according to any one of (1) to (10) above, wherein the display device is configured by arranging a plurality of the glass substrates in a tiled shape.

[0090] This application claims priority based on Japanese Patent Application No. 2020-019370, filed on February 7, 2020 in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0091] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur to those skilled in the art depending on design requirements and other factors, and that such modifications are within the scope of the appended claims and their equivalents.

Claims

1. a glass substrate having a first wiring pattern provided on a first main surface and a second wiring pattern provided on a second main surface opposite to the first main surface; a tapered opening portion provided so as to be exposed to the first main surface and having an opening diameter increasing toward the first main surface, and a through hole penetrating the glass substrate, the through hole including a through portion extending from the tapered opening portion in a thickness direction of the glass substrate; a connection portion provided inside the through hole and electrically connecting the first wiring pattern and the second wiring pattern; Equipped with the tapered opening has a first side surface that forms a first inclination angle with respect to the first main surface; the through portion has a second side surface that forms a second inclination angle with respect to the first main surface that is greater than the first inclination angle; The tapered opening has a maximum opening diameter at a position exposed to the first main surface, and the maximum opening diameter of the tapered opening is larger than a maximum opening diameter at the through portion. Display device.

2. The display device according to claim 1 , wherein the first wiring pattern includes a wiring pattern that is narrower than a minimum inner diameter of an opening of the through hole.

3. The display device according to claim 1 , wherein the connection portion is provided so as to cover an entire periphery of an inner side surface of the through hole with a conductive material.

4. The display device according to claim 1 , wherein a space inside the through hole is filled with an insulating material or a metallic material.

5. The display device according to claim 1 , further comprising an interlayer film on the first main surface of the glass substrate, the interlayer film covering the first wiring pattern.

6. The display device according to claim 5 , wherein the connection portion is electrically connected to the first wiring pattern through a via that penetrates the interlayer film.

7. The display device according to claim 5 , wherein the interlayer film has an opening, the opening having a diameter larger than a maximum opening diameter of the tapered opening, in a region corresponding to the through hole.

8. the second main surface of the glass substrate is covered with an insulating film; The display device according to claim 1 , wherein the second wiring pattern is provided so as to be partially exposed from the insulating film.

9. The display device according to claim 1 , wherein the first main surface and the second main surface of the glass substrate are flat except for an area where the through hole is provided.

10. The display device according to claim 1 , wherein the display device is a liquid crystal display device.

11. The display device according to claim 1 , wherein the display device is configured by arranging a plurality of the glass substrates in a tiled shape.

12. A display device as described in claim 1, wherein the opening diameter of the through hole continuously expands from the second main surface to the first main surface.

13. A display device as described in claim 1, wherein the through portion has a constant opening diameter in the thickness direction of the glass substrate, or has an opening diameter that expands continuously in the thickness direction of the glass substrate from the second main surface to the tapered opening.

14. A display device as described in claim 1, wherein the tapered opening has an opening diameter that expands continuously from the through portion to the first main surface.

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