Display device and method for manufacturing the same

Abstract

This display device comprises: a substrate on which a drive circuit is provided; an adhesive layer that covers the substrate; a first LED chip that is provided on the adhesive layer; a pixel circuit that is provided on the adhesive layer separately from the first LED chip; a light-shielding layer that is provided on the adhesive layer and that has a first opening which is substantially the same shape as the first LED chip in a plan view of the first LED chip, and a second opening which is substantially the same shape as the pixel circuit in a plan view of the pixel circuit; an insulation layer that covers the drive circuit and the pixel circuit; and first wiring that is provided on the insulation layer and the connects the first LED chip and the pixel circuit, wherein the first wiring overlaps with the light-shielding layer.

Description

[Technical field]

[0001] The present invention relates to a display device and a method for manufacturing a display device. [Background technology]

[0002] Development of so-called LED displays, which have tiny LED chips arranged in pixels arranged in a matrix, is underway as a next-generation display. LEDs are self-emitting elements similar to OLEDs, but unlike OLEDs, they are made of inorganic compounds containing gallium (Ga) and indium (In). Therefore, LED displays are easier to ensure high reliability compared to OLED displays. Furthermore, LEDs have high luminous efficiency and high brightness. Therefore, LED displays are expected to be next-generation displays with high reliability, high brightness, and high contrast.

[0003] In an LED display, it is necessary to separate the LEDs from a sapphire substrate (also called an element substrate) on which the LEDs are formed into individual LED chips, and to place each individual LED chip in a pixel of a circuit substrate (also called a backplane or TFT substrate). Patent Document 1 discloses an LED display in which an LED chip is provided in a recess provided in a planarizing film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Pat. No. 1,093,7815 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Document 1, wiring connected to an LED chip is routed on the display surface side of the LED display. In this case, the routed wiring connected to the LED chip reflects the light emitted by the LED chip. This causes a problem of reduced visibility of the LED display. In addition, if the positional accuracy for mounting the LED chip on the circuit board is improved, a problem of reduced manufacturing takt time occurs.

[0006] In view of the above problems, one embodiment of the present invention aims to provide a display device that suppresses reflection of light emitted from an LED chip by metal wiring and improves image visibility. Another embodiment of the present invention aims to improve the manufacturing takt time in alignment for mounting an LED chip on a circuit board. [Means for solving the problem]

[0007] A display device according to one embodiment of the present invention has a substrate on which a driving circuit is provided, an adhesive layer covering the substrate, a first LED chip provided on the adhesive layer, a pixel circuit provided on the adhesive layer at a distance from the first LED chip, a light-shielding layer provided on the adhesive layer and having a first opening having substantially the same shape as the first LED chip when viewed in a plane and a second opening having substantially the same shape as the pixel circuit when viewed in a plane, an insulating layer covering the driving circuit and the pixel circuit, and first wiring provided on the insulating layer and connecting the first LED chip and the pixel circuit, the first wiring overlapping the light-shielding layer.

[0008] A manufacturing method of a display device according to one embodiment of the present invention includes forming an adhesive layer on a substrate on which a drive circuit is provided, forming a light-shielding layer having a plurality of openings and a liquid-repellent surface on the adhesive layer, selectively applying a solvent onto the adhesive layer within the plurality of openings, placing a first LED chip so as to be in contact with the solvent within a first opening among the plurality of openings, placing a pixel circuit so as to be in contact with the solvent within a second opening among the plurality of openings, evaporating the solvent, bonding the adhesive layer to the first LED chip and bonding the adhesive layer to the pixel circuit, forming an insulating layer on the drive circuit, the first LED chip, and the pixel circuit, forming a first contact hole in the insulating layer that reaches the first LED chip and a second contact hole that reaches the pixel circuit, and forming a first wiring on the insulating layer that connects the first LED chip and the pixel circuit via the first contact hole and the second contact hole. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a display device according to an embodiment of the present invention; [Diagram 2] FIG. 2 is an enlarged view of a pixel in a display device according to one embodiment of the present invention. [Diagram 3] 1 is a schematic cross-sectional view of a pixel in a display device according to one embodiment of the present invention. [Figure 4] 2 is a schematic cross-sectional view of a peripheral region and a display region in a display device according to one embodiment of the present invention. FIG. [Diagram 5] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 6] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 7] 1A to 1C are plan views illustrating a manufacturing method of a display device according to an embodiment of the present invention. [Figure 8] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 9] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 10]5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 11] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 12] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 13] 2 is a schematic cross-sectional view of a peripheral region and a display region in a display device according to one embodiment of the present invention. FIG. [Figure 14] 1 is a schematic cross-sectional view of a pixel in a display device according to one embodiment of the present invention. [Figure 15] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 16] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. [Figure 17] 5A to 5C are cross-sectional views illustrating a method for manufacturing a display device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Each embodiment of the present invention will be described below with reference to the drawings. Note that each embodiment is merely an example, and those that a person skilled in the art can easily come up with by appropriately modifying the embodiment while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, in order to make the explanation clearer, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment. However, the illustrated shapes are merely examples and do not limit the interpretation of the present invention.

[0011] In each embodiment of the present invention, the direction from the substrate toward the LED chip is referred to as "upper", and the opposite direction is referred to as "lower". However, the expressions "upper" and "lower" merely describe the upper-level relationship of each element. For example, the expression that the LED chip is disposed on the substrate includes the case where another member is interposed between the substrate and the LED chip. Furthermore, the expressions "upper" and "lower" include not only the case where each element overlaps in a plan view, but also the case where they do not overlap.

[0012] When describing the embodiments of the present invention, elements having the same functions as elements already described may be given the same reference numerals or the same reference numerals plus a symbol such as an alphabet, and the description may be omitted. In addition, when it is necessary to describe an element by distinguishing between the RGB colors, the element is distinguished by adding the symbol R, G, or B after the reference numeral indicating the element. However, when it is not necessary to describe an element by distinguishing between the RGB colors, the element is described using only the reference numeral indicating the element.

[0013] (First embodiment) In this embodiment, a display device 100 according to one embodiment of the present invention will be described with reference to FIGS.

[0014] <Display device overview> 1 is a schematic diagram of a display device 100 according to an embodiment of the present invention. The display device 100 includes a substrate 101 having a display area 102 and a peripheral area 103 surrounding the display area 102. A plurality of pixels 110 are arranged in an array in the display area 102. Each pixel 110 includes an LED chip and a pixel circuit. A controller 104, a row control circuit 105, and a column control circuit 107 are arranged in the peripheral area 103. The row control circuit 105 and the column control circuit 107 are also referred to as drive circuits that drive the pixels 110.

[0015] The column control circuit 107 includes a column driver 108 connected to each column of the pixels 110. The column driver 108 is connected to a data line 136 that supplies a data signal commonly to all the pixels 110 arranged in the column. The row control circuit 105 also includes a row driver 106 connected to each row of the pixels 110. The row driver 106 is connected to a select line 134 that supplies a select signal commonly to all the pixels 110 arranged in the row. The array of pixels 110 is controlled by the controller 104 via the row control circuit 105 and the column control circuit 107.

[0016] <Display device configuration> 2 is an enlarged view of a pixel 110 when the display device 100 is viewed in plan. The pixel 110 has a plurality of LED chips 120 and a pixel circuit 130. The plurality of LED chips 120 include, for example, red, green, and blue LEDs that emit red, green, and blue light. A full-color pixel 110 can be configured by controlling the LED chips 120R, 120G, and 120B.

[0017] The pixel circuit 130 is formed on a substrate separate from the substrate 101. The pixel circuit 130 is, for example, a bare chip such as an unpackaged integrated circuit substrate, such as a semiconductor substrate.

[0018] Although not shown in FIG. 2, the LED chip 120 has two terminals. The two terminals of the LED chip 120 are disposed on the upper surface (upper side) of the LED chip 120. One terminal of the LED chip 120R is connected to the pixel circuit 130 via a wiring 118-1. One terminal of the LED chip 120G is connected to the pixel circuit 130 via a wiring 118-2. One terminal of the LED chip 120B is connected to the pixel circuit 130 via a wiring 118-3. The wiring 118-4 connects the other terminal of the LED chip 120R, the other terminal of the LED chip 120G, the other terminal of the LED chip 120B, and the pixel circuit 130, respectively. The wiring 118-5 connects the pixel circuit 130 to the pixel circuit 130 of the pixel 110 adjacent in the row direction. The wiring 118-6 connects the pixel circuit 130 to the pixel circuit 130 of the pixel 110 adjacent in the row direction. The wiring 118-7 connects the pixel circuit 130 to the LED chips 120R, 120G, and 120B of the pixels 110 adjacent in the column direction, respectively. Here, the wirings 118-5 and 118-6 connecting the pixels 110 adjacent in the row direction function as select lines. The select lines electrically connect the row driver 106 to the pixel circuits 130 of the pixels 110 adjacent in the row direction. The wirings 118-4 and 118-7 connecting the pixels 110 adjacent in the column direction function as data lines. The data lines electrically connect the column driver 108 to the LED chips 120 and pixel circuits 130 of the pixels 110 adjacent in the column direction.

[0019] Fig. 3 is a schematic cross-sectional view of the LED chips 120R, 120G, and 120B and the pixel circuit 130. Fig. 3 corresponds to a cross section of the pixel 110, but for ease of understanding, the schematic cross-sectional view shown in Fig. 3 does not correspond to the plan view of the pixel 110 shown in Fig. 2.

[0020] An insulating layer 144 and an insulating layer 152 are provided over a substrate 101. For example, a glass substrate, a resin substrate, a ceramic substrate, or a metal substrate is used as the substrate 101. For example, silicon oxide, silicon nitride, or the like is used as the insulating layer 144 and the insulating layer 152. The insulating layers 144 and 152 will be described in detail later.

[0021] Moreover, an adhesive layer 112 is provided on the insulating layer 152. The adhesive layer 112 is provided on one surface of the substrate 101. The adhesive layer 112 covers the display region 102 and the peripheral region 103. The adhesive layer 112 fixes the LED chips 120 arranged on the substrate 101. As the adhesive layer 112, an adhesive layer having sufficient light transmissivity in the visible light region, such as a VPA (vinyl sulfonic acid) adhesive layer, a polyimide adhesive layer, an acrylic adhesive layer, a silicone adhesive layer, a polyester adhesive layer, or a rubber adhesive layer, is used. The thickness of the adhesive layer 112 is, for example, 1 μm or more and 5 μm or less. If the thickness is thin, the adhesive force (bonding force) is weak, and if the thickness is thick, the cost increases and glue stains due to the adhesive layer are likely to occur.

[0022] On the adhesive layer 112, LED chips 120R, 120G, and 120B and a pixel circuit 130 are provided. A micro LED or a mini LED is used as the LED chip 120. A micro LED is an LED having a size of 100 μm or less, and a mini LED is an LED having a size of 100 μm to 200 μm. In the display device 100, an LED of either size can be used, and may be appropriately used according to the size of the pixel 110. In this embodiment, the LED chip 120 is a micro LED, and has a size of, for example, a vertical width of 7 μm to 150 μm, a horizontal width of 3 μm to 100 μm, and a height of about 3 μm to 15 μm. The LED chip 120 is arranged so that the terminals 122-1 and 122-2 are provided on the upper side. The terminals 122-1 and 122-2 are formed of a conductive material such as, for example, gold (Au), copper (Cu), silver (Ag), tin (Sn), or aluminum (Al). The same applies to the LED chips 120G and 120B and the pixel circuit 130. The LED chip 120 emits light to the substrate 101 side. Therefore, the substrate 101 side becomes the display surface of the display device 100.

[0023] A light-shielding layer 114 is provided on the adhesive layer 112. The light-shielding layer 114 is a black film having insulating properties. The light-shielding layer 114 is also called a black matrix. The light-shielding layer 114 has a plurality of openings 115. The plurality of openings 115 correspond to the positions where the LED chips 120R, 120G, and 120B and the pixel circuit 130 are disposed, respectively. As shown in FIG. 2, the LED chip 120R is disposed in the opening 115R in the light-shielding layer 114, the LED chip 120G is disposed in the opening 115G, the LED chip 120B is disposed in the opening 115B, and the pixel circuit 130 is disposed in the opening 115C. The shape of the opening 115R when viewed in a plane is substantially the same as the shape of the LED chip 120R when viewed in a plane. The thickness of the light-shielding layer 114 is preferably thinner than the height of the LED chip 120. For example, if the height of the LED is about 3 μm, the thickness of the light-shielding layer 114 should also be 3 μm or less.

[0024] An insulating layer 116 is provided so as to cover the light-shielding layer 114, the LED chips 120R, 120G, and 120B, and the pixel circuit 130. In FIG. 2, the insulating layer 116 is not shown. For example, an organic resin material such as polyimide, polyamide, acrylic, or epoxy may be used as the insulating layer 116. Also, for example, an inorganic material such as silicon oxide or silicon nitride may be used as the insulating layer 116. For example, the insulating layer 116 may be SOG (Spin on Glass). Also, for the insulating layer 116, a film of an inorganic material and a film of an organic resin material may be combined. When an organic resin material is used as the insulating layer 116, it functions as a planarizing film and can reduce the surface unevenness caused by the LED chips 120R, 120G, and 120B, and the pixel circuit 130. The insulating layer 116 is provided with a plurality of contact holes that expose the two terminals 122-1 and 122-2 of the LED chip 120 and the terminals 132-1 and 132-2 of the pixel circuit 130.

[0025] As shown in Fig. 3, a plurality of wirings 118-1 to 118-6 are provided on the insulating layer 116. In Fig. 3, for example, the wiring 118-4 connects the terminal 122B-2 of the LED chip 120B and the terminal 132-1 of the pixel circuit 130. Although the wirings 118-1 to 118-6 will not be described in detail, as described in Fig. 2, they connect the LED chip 120 and the pixel circuit 130. Signals for controlling light emission are supplied to the LED chips 120R, 120G, and 120B via the wirings 118-1 to 118-7 shown in Figs. 2 and 3.

[0026] FIG. 4 is a cross-sectional view of the peripheral region 103 and the display region 102. FIG. 4 shows a row driver 106 in the peripheral region 103. The row driver 106 and the column driver 108 are, for example, circuits configured with a plurality of transistors 150. A known transistor may be used as the transistor 150. In this embodiment, the transistor 150 is a bottom-gate transistor. The transistor 150 has a gate electrode 142, an insulating layer 144 functioning as a gate insulating layer, a semiconductor layer 146, and source or drain electrodes 148-1 and 148-2. In addition, an insulating layer 152 functioning as passivation is provided on the transistor 150.

[0027] One of the plurality of wirings 118 connects the pixel 110 to the row driver 106. For example, as shown in FIG. 4, in the peripheral region 103, the wiring 118-8 connects the source electrode or drain electrode 148-2 of the transistor 150 constituting the row driver 106 to the pixel circuit 130 of the pixel 110. In addition, another of the plurality of wirings 118 connects the pixel 110 to the column driver 108. In the peripheral region 103, the wiring 118 is connected to the source electrode or drain electrode 148-2 of the transistor 150 constituting the column driver 108. As shown in FIG. 4, the adhesive layer 112 and the light-shielding layer 114 are also provided in the peripheral region 103. The adhesive layer 112 and the light-shielding layer 114 cover the column control circuit 107, the row control circuit 105, and the controller 104. The wiring 118 and the source or drain electrode 148-2 are connected via contact holes formed in the insulating layer 116, the light-shielding layer 114, the adhesive layer 112, and the insulating layer 152. Although FIG. 4 shows an example in which the adhesive layer 112 and the light-shielding layer 114 are provided in the peripheral region 103, an embodiment of the present invention is not limited to this. A configuration in which the adhesive layer 112 and the light-shielding layer 114 are provided in the display region 102 and neither the adhesive layer 112 nor the light-shielding layer 114 is provided in the peripheral region 103 may be used. Alternatively, a configuration in which the adhesive layer 112 and the light-shielding layer 114 are provided in the display region 102 and the adhesive layer 112 or the light-shielding layer 114 is provided in the peripheral region 103 may be used.

[0028] The wiring 118 is made of a metal such as aluminum or copper. The gate electrode 142, the source or drain electrodes 148-1 and 148-2, and the wiring for routing the gate electrode 142 and the source or drain electrodes 148-1 and 148-2 are also made of a metal such as aluminum or copper. The wiring made of such a metal reflects the light emitted from the LED chip, reducing the visibility of the image. In addition, the light emitted by the LED chip is mixed, reducing the contrast.

[0029] In the display device 100 according to an embodiment of the present invention, the light-shielding layer 114 is provided in a region other than the region in which the LED chips 120R, 120G, and 120B and the pixel circuit 130 are provided. That is, in the display region 102, the gaps provided by the LED chips 120, 120G, and 120B and the pixel circuit 130 are filled with the light-shielding layer 114. In addition, the terminals of the LED chip 120 are provided on the upper side. Therefore, the multiple wirings 118 are routed above the light-shielding layer 114. This makes it possible to omit the wirings provided below the LED chips 120R, 120G, and 120B in the display region 102. In the display device 100, since the display surface is the lower side of the substrate 101, the multiple wirings 118 routed in the display region 102 can be shielded by the light-shielding layer 114. This makes it possible to provide a display device 100 that suppresses reflection of light emitted from the LED chips 120R, 120G, and 120B by the wiring 118 made of metal and improves image visibility. Since the region in which the drive circuit is disposed is separated from the region in which the LED chip 120 is disposed, the influence of the light emitted from the LED chip 120 can be reduced.

[0030] <Display Device Manufacturing Method> Next, a method for manufacturing the display device 100 according to one embodiment of the present invention will be described with reference to FIGS.

[0031] FIG. 5 is a diagram for explaining a process of forming a transistor 150 and an insulating layer 152 constituting a driving circuit in the peripheral region 103 on the substrate 101. FIG. 5 is a cross-sectional view of the display region 102 and the peripheral region 103. A known transistor forming method is applied to form the gate electrode 142, the insulating layer 144, the semiconductor layer 146, and the source or drain electrodes 148-1 and 148-2. The driving circuit is formed by the above process. After that, an insulating layer 152 that functions as a passivation layer is formed on the transistor 150. For example, a single layer of silicon oxide or silicon nitride, or a stacked layer of silicon oxide and silicon nitride may be used as the insulating layer 152. Here, the insulating layer 144 and the insulating layer 152 are also provided in the display region 102. Next, an opening 153 that exposes a part of the source or drain electrode 148-2 is formed in the insulating layer 152.

[0032] FIG. 6 is a diagram for explaining a process of forming an adhesive layer 112 on an insulating layer 152. FIG. 6 is a cross-sectional view of the display region 102. The adhesive layer 112 is formed not only in the display region 102 but also in the peripheral region 103. For the adhesive layer 112, an adhesive layer having sufficient light transmissivity in the visible light region, such as a VPA adhesive layer, a polyimide adhesive layer, an acrylic adhesive layer, a silicone adhesive layer, a polyester adhesive layer, or a rubber adhesive layer, is used. There is no particular limitation on the method of applying the adhesive layer 112, and for example, spin coating, slit coating, inkjet coating, roll coating, etc. are used. The thickness of the adhesive layer 112 is, for example, 1 μm or more and 5 μm or less. The adhesive layer 112 may be a thermosetting material or an ultraviolet curing material. By using an ultraviolet curing material as the adhesive layer 112, it may be processed into an arbitrary shape by patterning.

[0033] 7 and 8 are diagrams illustrating a process of forming a light-shielding layer 114 on the adhesive layer 112. FIG. 7 is a plan view of the substrate 101, and FIG. 8 is a cross-sectional view of the display region 102. The light-shielding layer 114 is formed not only in the display region 102 but also in the peripheral region 103. As described above, the thickness of the light-shielding layer 114 is determined according to the height of the LED chip 120.

[0034] As shown in FIG. 7, the light-shielding layer 114 has a plurality of openings 115R, 115G, 115B, and 115C. The LED chip 120R, the LED chip 120G, and the LED chip 120B are respectively provided in the plurality of openings 115R, 115G, and 115B later. The pixel circuit 130 is later provided in the opening 115C. Therefore, it is preferable that the area of ​​the openings 115R, 115G, 115B, and 115C is slightly larger than the area of ​​the LED chip 120 and the area of ​​the pixel circuit 130. For example, it is preferable that the shape of the opening 115R in a plan view is 1.05 to 1.5 times the shape of the LED chip 120R in a plan view. The relationship between the LED chips 120G and 120B and the pixel circuit 130 and the openings 115G, 115B, and 115C is the same as the relationship between the LED chip 120R and the opening 115R.

[0035] In a later process, it is necessary to apply a solvent for adhering the LED chip 120 and the pixel circuit 130 to the substrate 101. However, if the solvent is applied to the surface of the light-shielding layer 114, it becomes difficult to accurately attach the LED chip 120 and the pixel circuit 130 to the inside of the opening 115. Therefore, it is preferable that the surface of the light-shielding layer 114 has liquid repellency. In other words, it is preferable that the surface contact angle of the light-shielding layer 114 is larger than the surface contact angle of the adhesive layer 112 inside the opening 115. It is preferable that the surface contact angle of the light-shielding layer 114 is, for example, 85° or more. Since the surface of the light-shielding layer 114 has liquid repellency, it becomes easier to apply the solvent to the target area when applying the solvent later.

[0036] The liquid repellency of the light-shielding layer 114 can be improved by incorporating a fluorine-containing compound into a highly insulating black resin (e.g., cardo resin, low molecular weight acrylic resin, etc.). The liquid repellency of the light-shielding layer 114 can be adjusted by adjusting the content of the fluorine-containing compound. The more the fluorine-containing compound is, the higher the liquid repellency of the light-shielding layer 114 can be. A fluorine-containing compound is a compound that contains a fluorine atom.

[0037] When applying the light-shielding layer 114 by ink jetting, for example, a liquid-repellent component may be added to the black resist. The liquid-repellent component refers to a surfactant that contains fluorine. Fluorosurfactants are mixed uniformly in liquid form, but have the property of moving and segregating to the top layer of the film when applied or dried. By utilizing this property, if a fluorosurfactant is added to the black resist, the liquid repellency of only the upper layer of the light-shielding layer 114 can be increased when the black resist is applied and dried.

[0038] Furthermore, after the light-shielding layer 114 is formed, a fluororesin may be formed on the light-shielding layer 114 by a so-called lift-off technique. For example, a pattern is formed in the opening 115 using a resist. Next, a fluororesin film is formed on the light-shielding layer 114 and the pattern using the resist, and then the resist is removed. In this way, the fluororesin may be formed on the light-shielding layer 114.

[0039] In addition, after forming the light-shielding layer 114 from a black resin having insulating properties, fluorine or a fluorine compound (for example, CF 4 ) may be used for plasma treatment. For example, after forming a mask on the opening 115, the light-shielding layer 114 is exposed to an atmosphere in which a plasma containing fluorine is formed. A fluorine compound is generated on the surface of the light-shielding layer 114 made of a resin material. This may increase the liquid repellency of the surface of the light-shielding layer 114 compared to the surface of the adhesive layer 112 inside the opening 115.

[0040] 9 is a diagram for explaining a process of applying the solvent 117 to the opening 115 of the light-shielding layer 114. The solvent 117 includes a flux activator. As the flux activator, for example, a flux activator described in JP 2014-57019 A can be used. For example, the solvent 117 may be dropped into the inside of the opening 115 of the light-shielding layer 114 by an inkjet method. Furthermore, as a method for applying the solvent 117, an electrostatic dispensing method or a precision dispenser method may be used in addition to the inkjet method.

[0041] 8, the surface of the light-shielding layer 114 has liquid repellency. Therefore, even if the solvent 117 is applied to the surface of the light-shielding layer 114, the solvent 117 is repelled by the surface of the light-shielding layer 114, so that the solvent 117 can be selectively provided inside the opening 115.

[0042] FIG. 10 is a diagram for explaining a process of mounting the LED chip 120R, the LED chip 120G, the LED chip 120B, and the pixel circuit 130 in the multiple openings 115 of the light-shielding layer 114. In this embodiment, the solvent 117 is selectively provided inside the multiple openings 115. After picking up the LED chip 120 from the element substrate, the LED chip 120 is released on the solvent 117 and dropped. The timing of the release is the timing when the lower surface of the LED chip 120 comes into contact with the solvent 117. At this time, the solvent 117 and the LED chip 120 are in contact with each other, so that the LED chip 120 can be smoothly transferred onto the solvent 117. For the operations of holding, transporting, releasing, etc. the LED chip 120, a device (e.g., a chip mounter) that can suck the upper surface of the LED chip 120 and release the sucking as necessary is used. Alternatively, a transfer substrate may be used to pick up a plurality of LED chips from the element substrate, and the transfer substrate and the circuit substrate may be bonded together, after which the LED chips 120 may be separated from the carrier substrate, thereby disposing the LED chips 120 in the openings 115. The pixel circuits 130 are also placed on the solvent 117 in the same manner as the LED chips 120.

[0043] The position of the LED chip 120 placed on the solvent 117 fluctuates for a while with the fluctuation of the solvent 117. After a certain time, the shape of the solvent 117 stabilizes, and the position of the LED chip 120 also converges to a predetermined position. Here, the opening 115 of the light-shielding layer 114 on which the solvent 117 is provided is an area on which the outline of each LED chip 120 is projected, as described above. Therefore, the position where each LED chip 120 converges is a position that almost coincides with this opening 115. In this way, by forming the solvent 117 in the opening 115, the position of each LED chip 120 can be determined spontaneously and accurately by utilizing the surface tension of the solvent 117.

[0044] By positioning the LED chip 120 and the pixel circuit 130 in the above manner, it is possible to suppress misalignment when mounting the LED chip 120 or the pixel circuit 130 on the substrate 101. This makes it possible to improve the positional accuracy of the LED chip 120R, the LED chip 120G, the LED chip 120B, and the pixel circuit 130.

[0045] 11 is a diagram for explaining the step of drying the solvent 117. In the drying step, for example, the substrate 101 is heated at about 100° C. to evaporate the solvent 117. As a result, the flux activator remains between the adhesive layer 112 and the LED chip 120 and between the adhesive layer 112 and the pixel circuit 130. As a result, the LED chip 120R, the LED chip 120G, the LED chip 120B, and the pixel circuit 130 can be fixed to the adhesive layer 112. In this embodiment, the height of the LED chip 120R, the height of the LED chip 120G, and the height of the LED chip 120B are approximately the same.

[0046] FIG. 12 is a diagram for explaining a process of forming an insulating layer 116 on the LED chip 120 and the pixel circuit 130. The insulating layer 116 is formed in the display region 102 and the peripheral region 103. For example, an organic resin material such as acrylic, polyimide, polyamide, or epoxy is used as the insulating layer 116. The insulating layer 116 may have a thickness that covers the LED chip 120R, the LED chip 120G, the LED chip 120B, and the pixel circuit 130, and may have a thickness of, for example, 5 μm or more and 17 μm or less. Next, in the display region 102, contact holes are formed in the insulating layer 116 to expose the terminals 122-1 and 122-2 of the LED chip 120. In the peripheral region 103, contact holes are formed in the insulating layer 116, the light-shielding layer 114, and the adhesive layer 112 to expose the source electrode or the drain electrode 148-2. The depth of the contact holes formed in the display region 102 is different from the depth of the contact holes formed in the peripheral region 103. Therefore, it is preferable to form the contact holes in the display region 102 and the peripheral region 103 in different steps. In addition, although the present embodiment has been described with reference to a case where the openings 153 are formed in advance in the insulating layer 152, the embodiment of the present invention is not limited to this. When etching the insulating layer 116, the light-shielding layer 114, the adhesive layer 112, and the insulating layer 152, the contact holes may be formed all at once.

[0047] Finally, the wiring 118 is formed on the insulating layer 116. For example, a metal such as aluminum or copper is used as the wiring 118. A conductive film is formed on the insulating layer 116 and appropriately patterned to form the wiring 118. This allows the LED chip 120 and the pixel circuit 130 to be connected. Also, the pixel circuit 130 and the drive circuit to be connected.

[0048] Through the above steps, the display device 100 according to one embodiment of the present invention can be manufactured.

[0049] In this embodiment, a case has been described in which contact holes exposing the source or drain electrode 148-2 are formed in the insulating layer 116, the light-shielding layer 114, and the adhesive layer 112 in the peripheral region 103 in the step shown in Fig. 12, but an embodiment of the present invention is not limited thereto. For example, an opening may be formed in the light-shielding layer 114 in the peripheral region 103 in the step shown in Fig. 7 and Fig. 8, and a contact hole exposing the source or drain electrode 148-2 may be formed in the opening in the step shown in Fig. 12.

[0050] In the manufacturing method of the display device 100 according to one embodiment of the present invention, the surface of the light-shielding layer is made liquid-repellent, so that the solvent 117 applied to the surface of the light-shielding layer is repelled. This allows the solvent 117 to be positioned in the opening of the light-shielding layer with high precision. After the LED chip 120 and the pixel circuit 130 are placed on the solvent 117, the shape of the solvent 117 is stabilized, and the positions of the LED chip 120 and the pixel circuit are converged to predetermined positions. This allows the positioning of the LED chip 120 and the pixel circuit 130 to be performed with high precision in a short time. As described above, in the manufacturing method of the display device 100, the manufacturing tact time for aligning the LED chip and the pixel circuit for mounting them on the substrate can be improved.

[0051] In addition, in this embodiment, an example is described in which a circuit configured with transistors 150 is used as the row driver 106 or the column driver 108, but an embodiment of the present invention is not limited to this. As the row driver 106 and the column driver 108, for example, a bare chip 140 such as an unpackaged integrated circuit substrate such as a semiconductor substrate may be used.

[0052] 13 is a cross-sectional view of the peripheral region 103 and the display region 102 when a bare chip 140 is used as the row driver 106. When the bare chip 140 is used for each of the row driver 106 and the column driver 108, an adhesive layer 112 and a light-shielding layer 114 are provided on the substrate 101. An opening 115D is provided in the light-shielding layer 114. The bare chip 140 is arranged in the opening 115. A plurality of terminals 142-1 to 142-3 are provided on the bare chip 140. The wiring 118-9 connects the terminal 142-1 of the bare chip 140 to the pixel circuit 130 of the pixel 110. The wiring 118-10 connects the terminal 142-2 of the bare chip 140 to the terminal of the bare chip 140 of the adjacent row driver 106. Wiring 118-11 connects terminal 142-3 of bare chip 140 and a terminal of controller 104.

[0053] When the bare chip 140 is used for each of the row driver 106 and the column driver 108, it is not necessary to form a transistor on the substrate 101. When the bare chip is used for each of the row driver 106 and the column driver 108, the insulating layer 144 and the insulating layer 152 may be omitted as appropriate, and the adhesive layer 112 may be formed on the substrate 101. When forming the multiple openings 115R, 115G, 115B, and 115C in the light-shielding layer 114, the opening 115D for arranging the bare chip 140 may be formed. The subsequent steps can be performed in the same manner as the manufacturing process of the display region 102 described with reference to FIGS. 9 to 11, and therefore the manufacturing process of the display device 100 can be simplified.

[0054] Second embodiment In the first embodiment, the height of the LED chip 120R, the height of the LED chip 120G, and the height of the LED chip 120B are described as being approximately the same, but the embodiment of the present invention is not limited thereto. The height of the LED chip 120R, the height of the LED chip 120G, and the height of the LED chip 120B may differ for each color. The heights of the LED chips 120R, 120G, and 120B may differ by about 8 μm to 12 μm due to differences in structure and the like. The difference in height of the LED chips 120R, 120G, and 120B causes a problem that the connection surfaces between the terminals 122-1 and 122-2 and the wiring 118 are not uniform. In addition, the depth of the contact hole formed in the insulating layer 116 is different between the terminal of the LED chip 120 with a small height and the terminal of the LED chip 120 with a large height. Therefore, it may be difficult to form a contact hole in the insulating layer 116 according to the height of the LED chip 120, or the wiring 118 may be broken when the wiring is formed.

[0055] Therefore, when the heights of the LED chips 120R, 120G, and 120B differ for each color, it is preferable to adjust the thickness of the adhesive layer 112 so that the connection surfaces between the terminals 122-1 and 122-2 and the wiring 118 are uniform.

[0056] <Display device configuration> Fig. 14 is a cross-sectional view of a pixel 110 in a display device 100A according to one embodiment of the present invention. Fig. 14 corresponds to a cross-section of the pixel 110, but for ease of understanding, the schematic cross-sectional view shown in Fig. 14 does not correspond to the plan view of the pixel 110 shown in Fig. 2.

[0057] In this embodiment, as shown in FIG. 14, a case will be described in which the height of the LED chips increases in the order of the LED chip 120B, the LED chip 120R, and the LED chip 120G. In this case, the thickness of the adhesive layer 112 in the area where the LED chips 120R, 120G, and 120B are arranged is adjusted so that the connection surface between the terminals and the wiring 118 in the LED chips 120R, 120G, and 120B is uniform. In FIG. 14, the thickness of the adhesive layer 112 inside the opening 115R where the LED chip 120R is provided is thickness t1. The thickness of the adhesive layer 112 inside the opening 115G where the LED chip 120G is provided is thickness t2. The thickness of the adhesive layer 112 inside the opening 115B where the LED chip 120B is provided is thickness t3. The thickness of the adhesive layer 112 overlapping the light-shielding layer 114 is thickness t4. The thickness of the adhesive layer 112 inside the opening 115C where the pixel circuit 130 is provided is thickness t5.

[0058] As described above, in this embodiment, the LED chips 120B, 120R, and 120G are increased in height in this order. Therefore, the thickness of the adhesive layer 112 is adjusted so that the thickness of the adhesive layer 112 is increased in the order of thickness t2, thickness t1, and thickness t3. Also, depending on the height of the LED chip 120G, the thickness t2 and the thickness t4 may be the same size, or the thickness t2 may be greater than the thickness t4. In FIG. 14, the case where the thickness t5 is greater than the thickness t3 is shown, but the thickness t5 may be appropriately set depending on the height of the pixel circuit 130. Therefore, when the height of the terminal of the pixel circuit 130 is different from the height of the LED chips 120R, 120G, and 120B, the thicknesses t1 to t5 may be adjusted. This makes it possible to make the connection surfaces between the terminals of the LED chips 120R, 120G, and 120B and the pixel circuit 130 and the wiring 118 uniform.

[0059] <Display Device Manufacturing Method> A method for manufacturing the display device 100A shown in Fig. 14 will be described with reference to Fig. 4, Fig. 5, Fig. 9 to Fig. 12, and Fig. 15 to Fig. 17. Note that detailed description of the same steps as in the first embodiment will be omitted.

[0060] The process of forming the transistor 150 and the insulating layer 152 over the substrate 101 is similar to the process shown in FIG.

[0061] In this embodiment, in order to adjust the thickness of the adhesive layer 112 inside the openings 115R, 115G, 115B, and 115C, for example, a photoresist having adhesive properties is used as the adhesive layer 112. For example, the above-mentioned VPA (vinyl sulfonic acid)-based adhesive layer or the like may be used as the photoresist having adhesive properties.

[0062] First, similarly to the process shown in FIG. 5, an adhesive layer 112 having a uniform thickness is formed on the insulating layer 152. Next, as shown in FIG. 15, adhesive layers 112a, 112b, and 112c are partially formed. The region 113a where the adhesive layer 112a is formed is the region where the LED chip 120R is provided, the region 113b where the adhesive layer 112b is formed is the region where the LED chip 120B is provided, and the region 113c where the adhesive layer 112c is formed is the region where the pixel circuit 130 is provided. Also, in FIG. 15, the adhesive layer 112a, the adhesive layer 112b, and the adhesive layer 112c are thicker in this order. The thicknesses of the adhesive layer 112a, the adhesive layer 112b, and the adhesive layer 112c are different depending on the heights of the LED chips 120R, 120G, and 120B and the pixel circuit 130 to be placed later. The other regions are the regions where the light-shielding layer 114 and the LED chip 120G are provided. By using a photoresist having adhesive properties as the adhesive layer 112, it is possible to form the adhesive layer 112 with different thicknesses in predetermined regions. If necessary, the adhesive layer may be partially formed in the region where the LED chip 120G is provided.

[0063] The adhesive layer 112 having different thicknesses is formed, for example, by forming an adhesive layer with a predetermined thickness in each of the regions 113a, 113b, and 113c, then forming an adhesive layer with a predetermined thickness in each of the regions 113b and 113c, and finally forming an adhesive layer with a predetermined thickness in the region 113c. In this way, the adhesive layer 112 provided with the adhesive layers 112a, 112b, and 112c can be formed.

[0064] Fig. 16 is a diagram illustrating a process of forming a light-shielding layer 114 on an adhesive layer 112. As shown in Fig. 16, the thickness of the light-shielding layer 114 is preferably greater than the thickness of the adhesive layer 112c, which is the thickest among the adhesive layers 112a, 112b, and 112c. If the thickness of the light-shielding layer 114 is less than the thickness of the adhesive layer 112c, the solvent 117 will overflow from the openings 115 of the light-shielding layer 114.

[0065] The process of providing the LED chip 120 and the pixel circuit 130 on the adhesive layer 112 is similar to that described with reference to FIGS. 9 to 11, and therefore a detailed description thereof will be omitted.

[0066] FIG. 17 is a diagram for explaining a process of forming the insulating layer 116 on the LED chip 120 and the pixel circuit 130. The insulating layer 116 is formed in the display region 102 and the peripheral region 103. The material and thickness of the insulating layer 116 are as described in FIG. 12. Next, contact holes are formed in the insulating layer 116. As a result, the terminals 122R-1, 122R-2, 122G-1, 122G-2, 122B-1, 122B-2, 132-1, and 132-2 are exposed from the insulating layer 116. Also, the wiring or terminals of the driving circuit are exposed from the insulating layer 116. Finally, the wirings 118-1 to 118-8 are formed on the insulating layer 116. A conductive film is formed on the insulating layer 116 and appropriately patterned to form the wirings 118-1 to 118-8. As a result, the LED chip 120 and the pixel circuit 130 can be connected by the wirings 118. In addition, the pixel circuit 130 and a driver circuit can be connected through the wiring 118.

[0067] Through the above steps, the display device 100A according to one embodiment of the present invention shown in FIG. 14 can be manufactured.

[0068] According to the display device 100A of this embodiment, even if the heights of the LED chip 120R, the LED chip 120G, and the LED chip 120B are different for each color, the connection surfaces between the terminals 122-1 and 122-2 and the wiring 118 can be made uniform. This allows the depth of the contact holes formed in the insulating layer 116 to be approximately the same regardless of the height of the LED chip 120. This makes it easy to form the contact holes in the insulating layer 116, and prevents the wiring 118 from being broken when the wiring is formed.

[0069] The above-described embodiments of the present invention may be combined as appropriate as long as they are not mutually inconsistent. In addition, a display device according to any of the embodiments may be combined as appropriate by a person skilled in the art to add or remove components or modify the design, or to add or omit steps or modify conditions, and the combination is included in the scope of the present invention as long as it includes the gist of the present invention.

[0070] Even if there are other effects and advantages different from those brought about by the aspects of each of the above-mentioned embodiments, those that are clear from the description in this specification or that can be easily predicted by a person skilled in the art are naturally understood to be brought about by the present invention. [Explanation of symbols]

[0071] 100: display device, 101: substrate, 102, 102A: display area, 103: peripheral area, 104: controller, 105: row control circuit, 106: row driver, 107: column control circuit, 108: column driver, 110: pixel, 112: adhesive layer, 114: light shielding layer, 115, 115R, 115G, 115B, 115C: opening, 116: insulating layer, 117: solvent, 118 : wiring, 120, 120R, 120G, 120B: LED chip, 122R-1, 122R-2, 122G-1, 122G-2, 122B-1, 122B-2: terminal, 124: photoresist, 130: pixel circuit, 142: gate electrode, 144: insulating layer, 146: semiconductor layer, 148-1, 148-2: source electrode or drain electrode, 150: transistor

Claims

1. A substrate on which a drive circuit is provided; An adhesive layer covering the substrate; A first LED chip provided on the adhesive layer; a pixel circuit provided on the adhesive layer and spaced apart from the first LED chip; a light-shielding layer provided on the adhesive layer, the light-shielding layer having a first opening having a shape substantially the same as a shape of the first LED chip when viewed in a plane, and a second opening having a shape substantially the same as a shape of the pixel circuit when viewed in a plane; an insulating layer covering the driving circuit and the pixel circuit; a first wiring provided on the insulating layer and connecting the first LED chip and the pixel circuit; The display device, wherein the first wiring overlaps with the light-shielding layer.

2. a second wiring provided on the insulating layer and electrically connecting the pixel circuit and the drive circuit; the first LED chip and the pixel circuit are provided in a display area, the drive circuit is provided in a peripheral region surrounding the display region, The display device according to claim 1 , wherein the second wiring is electrically connected to the drive circuit in the peripheral region through a contact hole provided in the insulating layer.

3. The height of the pixel circuit is different from the height of the first LED chip, The display device according to claim 2 , wherein the adhesive layer has a thickness in a first region in which the first LED chip is disposed, the thickness being different from a thickness in a second region in which the pixel circuit is disposed.

4. The display device according to claim 3 , wherein a height of a surface of the first LED chip that is connected to the first wiring is the same as a height of a surface of the pixel circuit that is connected to the second wiring.

5. a second LED chip provided on the adhesive layer in the display area and having a different light emission color from the first LED chip; a third wiring provided on the insulating layer and connecting the second LED chip and the pixel circuit; The display device according to claim 2 , wherein the light-shielding layer further includes a third opening having substantially the same shape as the second LED chip in a plan view.

6. The height of the second LED chip is different from the height of the first LED chip, The display device of claim 5 , wherein the adhesive layer has a thickness in a first region where the first LED chip is arranged different from a thickness in a third region where the second LED chip is arranged.

7. The display device according to claim 6 , wherein a height of a surface of the first LED chip that is connected to the first wiring is the same as a height of a surface of the second LED chip that is connected to the third wiring.

8. The display device according to claim 1 , wherein the surface of the light-shielding layer comprises fluorine or a fluorine compound.

9. The display device according to claim 1 , wherein the thickness of the light-shielding layer is smaller than the height of the first LED chip.

10. An adhesive layer is formed on a substrate on which a driving circuit is provided, forming a light-shielding layer having a plurality of openings and a liquid-repellent surface on the adhesive layer; selectively applying a solvent onto the adhesive layer within the plurality of openings; placing a first LED chip in a first opening among the plurality of openings so as to be in contact with the solvent; placing a pixel circuit in contact with the solvent in a second opening among the plurality of openings; The solvent is evaporated to bond the adhesive layer to the first LED chip and to bond the adhesive layer to the pixel circuit; forming an insulating layer on the driving circuit, the first LED chip, and the pixel circuit; forming a first contact hole in the insulating layer, the first contact hole reaching the first LED chip and a second contact hole reaching the pixel circuit; forming a first wiring on the insulating layer, the first wiring connecting the first LED chip and the pixel circuit via the first contact hole and the second contact hole.

11. The height of the first LED chip is different from the height of the pixel circuit, Forming the adhesive layer comprises: The method of claim 10, wherein the adhesive layer is formed to have a different thickness in a first region where the first LED chip is provided and a second region where the pixel circuit is provided.

12. After mounting the first LED chip, placing a second LED chip in a third opening among the plurality of openings so as to be in contact with the solvent; The method of claim 10, further comprising: evaporating the solvent to adhere the adhesive layer and the second LED chip.

13. The height of the first LED chip is different from the height of the second LED chip, Forming the adhesive layer includes: The method of claim 12, further comprising forming the adhesive layer to have a different thickness in a first region where the first LED chip is provided and a third region where the second LED chip is provided.

14. The method for manufacturing a display device according to claim 10 , wherein the surface contact angle of the liquid-repellent light-shielding layer is 90° or more.

15. The formation of the liquid-repellent light-shielding layer is The method for manufacturing a display device according to claim 10 , further comprising forming an insulating black resin on the adhesive layer, and then performing a plasma treatment using a gas containing fluorine or a fluorine compound.

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