Display device and method for manufacturing a display device

Abstract

A display device includes a substrate provided with a drive circuit, an adhesive layer covering the substrate, a first LED chip provided on the adhesive layer, a pixel circuit provided on the adhesive layer separately from the first LED chip, a light-blocking layer provided on the adhesive layer and having a first opening portion having substantially the same shape as a shape of the first LED chip as viewed in plan and a second opening portion having substantially the same shape as a shape of the pixel circuit as viewed in plan, an insulating layer covering the drive circuit and the pixel circuit, and a first wiring provided on the insulating layer and connecting the first LED chip and the pixel circuit, the first wiring overlapping the light-blocking layer.

Description

Technical Field

[0001] This invention relates to a display device and a method for manufacturing a display device. Background Technology

[0002] As a next-generation display, LED displays are being developed, which incorporate tiny LED chips arranged in a matrix of pixels. LEDs are self-emissive elements similar to OLEDs, but unlike OLEDs, they are composed of inorganic compounds containing gallium (Ga) and indium (In). Therefore, compared to OLED displays, LED displays are easier to ensure in terms of reliability. Furthermore, LEDs have high luminous efficiency and high brightness. Consequently, LED displays are expected to be a next-generation display offering high reliability, high brightness, and high contrast.

[0003] In LED displays, it is necessary to separate individual LED chips from the sapphire substrate (also called the component substrate) where the LEDs are formed, and to arrange each LED chip in a pixel on a circuit board (backplane, also called a TFT substrate). Patent Document 1 discloses an LED display in which LED chips are disposed in a recess provided on a planarization film.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: US Patent No. 10937815 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] In Patent Document 1, wiring connected to the LED chip is wound around the display surface of the LED display. In this case, the wiring connected to the LED chip is reflected by the light emitted from the LED chip. This results in a decrease in the visual legibility of the LED display. Furthermore, if the positional accuracy for mounting the LED chip on the circuit board is improved, a decrease in manufacturing cycle time is generated.

[0009] In view of the above problems, one object of an embodiment of the present invention is to provide a display device that suppresses the reflection of light emitted from an LED chip by wiring formed of metal, thereby improving the visual recognizability of the image. Alternatively, one object of an embodiment of the present invention is to improve the manufacturing cycle time for aligning the LED chip onto the circuit board.

[0010] Means for solving technical problems

[0011] A display device according to one embodiment of the present invention includes: a substrate having a driving circuit; an adhesive layer covering the substrate; a first LED chip disposed on the adhesive layer; a pixel circuit disposed on the adhesive layer separately from the first LED chip; a light-shielding layer disposed on the adhesive layer, having a first opening having a shape substantially the same as the shape of the first LED chip when viewed from above and a second opening having a shape substantially the same as the shape of the pixel circuit when viewed from above; an insulating layer covering the driving circuit and the pixel circuit; and a first wiring disposed on the insulating layer connecting the first LED chip and the pixel circuit, the first wiring overlapping the light-shielding layer.

[0012] A method for manufacturing a display device according to an embodiment of the present invention includes the following steps: forming an adhesive layer on a substrate having a driving circuit; forming a light-shielding layer on the adhesive layer, the light-shielding layer having a plurality of openings and being hydrophobic on its surface; selectively applying a solvent to the adhesive layer within the plurality of openings; placing a first LED chip in contact with the solvent in a first opening among the plurality of openings; placing a pixel circuit in contact with the solvent in a second opening among the plurality of openings; causing the solvent to evaporate to bond the adhesive layer to the first LED chip and 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 reaching the first LED chip and a second contact hole reaching the pixel circuit on the insulating layer; 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. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a display device according to an embodiment of the present invention.

[0014] Figure 2 This is a magnified view of the pixels in a display device according to an embodiment of the present invention.

[0015] Figure 3 This is a cross-sectional schematic diagram of a pixel in a display device according to an embodiment of the present invention.

[0016] Figure 4 This is a cross-sectional schematic diagram of the peripheral area and the display area in a display device according to an embodiment of the present invention.

[0017] Figure 5 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0018] Figure 6 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0019] Figure 7This is a top view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0020] Figure 8 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0021] Figure 9 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0022] Figure 10 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0023] Figure 11 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0024] Figure 12 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0025] Figure 13 This is a cross-sectional schematic diagram of the peripheral area and the display area in a display device according to an embodiment of the present invention.

[0026] Figure 14 This is a cross-sectional schematic diagram of a pixel in a display device according to an embodiment of the present invention.

[0027] Figure 15 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0028] Figure 16 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention.

[0029] Figure 17 This is a cross-sectional view illustrating a method for manufacturing a display device according to an embodiment of the present invention. Detailed Implementation

[0030] Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, each embodiment is merely an example, and any content that can be readily conceived by those skilled in the art through appropriate modifications while maintaining the spirit of the invention is, of course, included within the scope of the present invention. Additionally, to make the description clearer, the accompanying drawings sometimes schematically show the width, thickness, shape, etc., of various parts compared to the actual embodiments. However, the shapes shown are merely examples and do not limit the interpretation of the present invention.

[0031] In various embodiments of the present invention, the direction from the substrate toward the LED chip is defined as "up," and the opposite direction is defined as "down." The terms "above" or "below" are used only to describe the vertical relationship between the elements. For example, the description of "arranging the LED chip above the substrate" also includes cases where other components are sandwiched between the substrate and the LED chip. Furthermore, the terms "above" or "below" include not only cases where the elements overlap when viewed from above, but also cases where they do not overlap.

[0032] When describing embodiments of the present invention, elements having the same function as those already described are sometimes labeled with the same reference numerals or have Latin letters or other symbols added to the same reference numerals, thus omitting the description. Furthermore, for a particular element, if it is necessary to distinguish it from the various RGB colors in the description, an R, G, or B symbol is added after the reference numeral representing that element to differentiate it. However, for an element where it is not necessary to distinguish it from the various RGB colors in the description, only the reference numeral representing that element is used for description.

[0033] (First Implementation)

[0034] In this embodiment, refer to Figures 1 to 13 A display device 100 according to one embodiment of the present invention will be described.

[0035] <Overview of the display device>

[0036] Figure 1 This 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 pixel circuitry. A controller 104, a row control circuit 105, and a column control circuit 107 are disposed in the peripheral area 103. The row control circuit 105 and the column control circuit 107 are also referred to as driving circuits for driving the pixels 110.

[0037] The column control circuit 107 includes column drivers 108 connected to each column of pixels 110. The column drivers 108 are connected to a data line 136, which supplies data signals to all pixels 110 arranged in the column. Additionally, the row control circuit 105 includes row drivers 106 connected to each row of pixels 110. The row drivers 106 are connected to a select line 134, which supplies select signals to all 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.

[0038] <Composition of the display device>

[0039] Figure 2 This is a magnified view of pixel 110 when viewed from above the display device 100. Pixel 110 has multiple LED chips 120 and pixel circuitry 130. The multiple LED chips 120 include, for example, red, green, and blue LEDs that emit red, green, and blue light. By controlling LED chips 120R, 120G, and 120B, a full-color pixel 110 can be constructed.

[0040] The pixel circuit 130 is formed on a substrate different from the substrate 101. The pixel circuit 130 is, for example, a bare chip such as an unpackaged integrated circuit substrate, like a semiconductor substrate.

[0041] Figure 2 Although not shown in the diagram, LED chip 120 has two terminals. The two terminals of LED chip 120 are located on the upper surface (upper side) of LED chip 120. One terminal of LED chip 120R is connected to pixel circuit 130 via wiring 118-1. One terminal of LED chip 120G is connected to pixel circuit 130 via wiring 118-2. One terminal of LED chip 120B is connected to pixel circuit 130 via wiring 118-3. Wiring 118-4 connects the other terminal of LED chip 120R, the other terminal of LED chip 120G, the other terminal of LED chip 120B, and pixel circuit 130 respectively. Wiring 118-5 connects pixel circuit 130 to the pixel circuit 130 of pixel 110 adjacent in the row direction. Wiring 118-6 connects pixel circuit 130 to the pixel circuit 130 of pixel 110 adjacent in the row direction. Wiring 118-7 connects the pixel circuit 130 to the LED chips 120R, 120G, and 120B of the adjacent pixels 110 in the column direction, respectively. Here, wiring 118-5 and 118-6, connecting the adjacent pixels 110 in the row direction, function as selection lines. The selection lines electrically connect the row driver 106 to the pixel circuit 130 of the adjacent pixels 110 in the row direction. Wiring 118-4 and 118-7, connecting the adjacent pixels 110 in the column direction, function as data lines. The data lines electrically connect the column driver 108 to the LED chip 120 and pixel circuit 130 of the adjacent pixels 110 in the column direction.

[0042] Figure 3 This is a cross-sectional schematic diagram of LED chips 120R, 120G, 120B and pixel circuit 130. Figure 3 Corresponding to the cross-section of pixel 110, but for ease of explanation, Figure 3 The cross-sectional schematic diagram shown is not consistent with Figure 2 The top view corresponding to pixel 110 is shown.

[0043] An insulating layer 144 and an insulating layer 152 are provided on a substrate 101. The substrate 101 may be, for example, a glass substrate, a resin substrate, a ceramic substrate, or a metal substrate. The insulating layers 144 and 152 may be, for example, silicon oxide or silicon nitride. The insulating layers 144 and 152 will be described in detail later.

[0044] Additionally, an adhesive layer 112 is provided on the insulating layer 152. The adhesive layer 112 is provided on one side of the substrate 101. Furthermore, the adhesive layer 112 covers the display area 102 and the surrounding area 103. The adhesive layer 112 fixes the LED chips 120 arranged on the substrate 101. As the adhesive layer 112, for example, an adhesive layer with sufficient light transmittance in the visible light region is used, 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. The thickness of the adhesive layer 112 is, for example, 1 μm or more and 5 μm or less. If the thickness is too thin, the adhesion (bonding force) will be weak; if the thickness is too thick, the cost will increase, and paste stains caused by the adhesive layer are more likely to occur.

[0045] LED chips 120R, 120G, and 120B, as well as pixel circuitry 130, are disposed on the adhesive layer 112. The LED chip 120 is a micro LED or a small LED. A micro LED is an LED with a size of 100 μm or less, while a small LED is an LED with a size of 100 μm to 200 μm. In the display device 100, LEDs of any size can be used, and the appropriate size can be selected based on the size of the pixel 110. In this embodiment, the LED chip 120 is a micro LED, for example, having a vertical width of 7 μm to 150 μm, a horizontal width of 3 μm to 100 μm, and a height of approximately 3 μm to 15 μm. The LED chip 120 is configured with terminals 122-1 and 122-2 disposed on its upper side. Terminals 122-1 and 122-2 are formed, for example, of conductive materials such as gold (Au), copper (Cu), silver (Ag), tin (Sn), and aluminum (Al). The same applies to LED chips 120G and 120B, as well as pixel circuit 130. LED chip 120 emits light toward substrate 101. Therefore, substrate 101 becomes the display surface of display device 100.

[0046] A light-shielding layer 114 is provided on the adhesive layer 112. The light-shielding layer 114 is an insulating black film. The light-shielding layer 114 is also referred to as a black matrix. The light-shielding layer 114 has a plurality of openings 115. The plurality of openings 115 correspond to the positions where LED chips 120R, 120G, 120B and pixel circuit 130 are disposed. Figure 2As shown, an LED chip 120R is disposed in opening 115R, an LED chip 120G is disposed in opening 115G, an LED chip 120B is disposed in opening 115B, and a pixel circuit 130 is disposed in opening 115C. Furthermore, the shape of the opening 115R viewed from above is approximately the same as the shape of the LED chip 120R viewed from above. Preferably, the thickness of the light-shielding layer 114 is thinner than the height of the LED chip 120. For example, if the height of the LED is approximately 3 μm, then the thickness of the light-shielding layer 114 can also be less than 3 μm.

[0047] An insulating layer 116 is provided to cover the light-shielding layer 114, LED chips 120R, 120G, 120B, and pixel circuitry 130. Figure 2 The illustration of insulating layer 116 is omitted. Insulating layer 116 can be made of organic resin materials such as polyimide, polyamide, acrylic, and epoxy. Alternatively, it can be made of inorganic materials such as silicon oxide and silicon nitride. Insulating layer 116 can also be SOG (Spin-on Glass). Furthermore, insulating layer 116 can be a combination of films of inorganic materials and films of organic resin materials. When using organic resin materials, insulating layer 116 functions as a planarization film, mitigating surface irregularities caused by LED chips 120R, 120G, 120B, and pixel circuit 130. Insulating layer 116 has multiple contact holes that expose the two terminals 122-1 and 122-2 of LED chip 120 and the terminals 132-1 and 132-2 of pixel circuit 130.

[0048] like Figure 3 As shown, multiple wirings 118-1 to 118-6 are provided on the insulating layer 116. Figure 3 For example, wiring 118-4 connects terminal 122B-2 of LED chip 120B to terminal 132-1 of pixel circuit 130. Regarding wiring 118-1 to 118-6, although not described in detail, it is possible to find similar connections in... Figure 2 The LED chip 120 is connected to the pixel circuit 130 as described in the instructions. Using... Figure 2 as well as Figure 3 The wiring 118-1 to 118-7 shown provides signals to control the light emission of each LED chip 120R, 120G, and 120B.

[0049] Figure 4 It is a cross-sectional view of the surrounding area 103 and the display area 102. Figure 4The row driver 106 in the peripheral region 103 is shown. The row driver 106 and the column driver 108 are, for example, circuits composed of multiple transistors 150. Known transistors can be used for the transistors 150. In this embodiment, the transistor 150 is shown as a bottom-gate type 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, 148-2. Additionally, an insulating layer 152 functioning as a passivation layer is provided on the transistor 150.

[0050] One of the multiple wirings 118 connects pixel 110 to line driver 106. For example, Figure 4 As shown, in the peripheral region 103, wiring 118-8 connects the source or drain electrode 148-2 of the transistor 150 constituting the row driver 106 to the pixel circuit 130 of the pixel 110. Additionally, another wiring 118 of the plurality of wirings connects the pixel 110 to the column driver 108. In the peripheral region 103, this wiring 118 is connected to the source or drain electrode 148-2 of the transistor 150 constituting the column driver 108. Figure 4 As shown, an adhesive layer 112 and a light-shielding layer 114 are also provided in the surrounding area 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. Wiring 118 is connected to the source electrode or drain electrode 148-2 via contact holes formed in the insulating layer 116, the light-shielding layer 114, the adhesive layer 112, and the insulating layer 152. Additionally, in Figure 4 The illustration shows an example where an adhesive layer 112 and a light-shielding layer 114 are provided in the peripheral area 103, but this embodiment of the invention is not limited to this. It is also possible to employ a configuration where the adhesive layer 112 and the light-shielding layer 114 are provided in the display area 102, and neither the adhesive layer 112 nor the light-shielding layer 114 is provided in the peripheral area 103. Alternatively, it is also possible to employ a configuration where the adhesive layer 112 and the light-shielding layer 114 are provided in the display area 102, and either the adhesive layer 112 or the light-shielding layer 114 is provided in the peripheral area 103.

[0051] For example, metals such as aluminum or copper are used for wiring 118. Furthermore, the wiring around the gate electrode 142, source electrode, or drain electrode 148-1, 148-2, and the wiring for winding the gate electrode 142, source electrode, or drain electrode 148-1, 148-2 are also formed of metals such as aluminum or copper. This metal-formed wiring reflects light emitted from the LED chip, reducing the visual recognizability of the image. Additionally, the light emitted by the LED chip mixes colors, reducing contrast.

[0052] In a display device 100 according to one embodiment of the present invention, a light-shielding layer 114 is provided outside the area where the LED chips 120R, 120G, 120B and the pixel circuit 130 are disposed. That is, in the display area 102, the gaps between the LED chips 120, 120G, 120B and the pixel circuit 130 are filled by the light-shielding layer 114. In addition, the terminals of the LED chips 120 are provided on top. Therefore, a plurality of wirings 118 are wound around the top of the light-shielding layer 114. As a result, the wirings provided below the LED chips 120R, 120G, 120B can be omitted in the display area 102. In the display device 100, the display surface is the lower side of the substrate 101, so the plurality of wirings 118 wound in the display area 102 can be shielded from light by the light-shielding layer 114. Therefore, a display device 100 can be provided that suppresses the reflection of light emitted from LED chips 120R, 120G, and 120B by the metal wiring 118, thereby improving the visual recognizability of the image. In addition, since the area for configuring the driving circuit is separated from the area for configuring the LED chips 120, the influence of light emitted from the LED chips 120 can be reduced.

[0053] <Manufacturing Method of Display Device>

[0054] Next, refer to Figures 5-12 A method for manufacturing a display device 100 according to an embodiment of the present invention will be described.

[0055] Figure 5 This diagram illustrates the process of forming a transistor 150 constituting a driving circuit and an insulating layer 152 in a peripheral region 103 on a substrate 101. Figure 5 This is a cross-sectional view of the display area 102 and the surrounding area 103. The transistor 150 is formed using a known transistor formation method, forming a gate electrode 142, an insulating layer 144, a semiconductor layer 146, and source or drain electrodes 148-1 and 148-2. Through the above steps, a driving circuit is formed. Next, an insulating layer 152, functioning as a passivation layer, is formed on the transistor 150. The insulating layer 152 can be, for example, a single layer of silicon oxide or silicon nitride, or a stack of silicon oxide and silicon nitride. Here, the insulating layer 144 and the insulating layer 152 are also provided in the display area 102. Next, an opening 153 is formed in the insulating layer 152, exposing a portion of the source or drain electrodes 148-2.

[0056] Figure 6 This diagram illustrates the process of forming an adhesive layer 112 on the insulating layer 152. Figure 6A cross-sectional view of the display area 102. The adhesive layer 112 is formed not only in the display area 102 but also in the surrounding area 103. As the adhesive layer 112, for example, an adhesive layer with sufficient light transmittance in the visible light region is used, such as a VPA-based adhesive layer, a polyimide-based adhesive layer, an acrylic adhesive layer, a silicone-based adhesive layer, a polyester adhesive layer, or a rubber-based adhesive layer. There are no particular limitations on the coating method for the adhesive layer 112, but methods such as spin coating, slot coating, inkjet coating, and roller coating can be used. The film thickness of the adhesive layer 112 is, for example, 1 μm or more and 5 μm or less. The adhesive layer 112 can be a thermosetting material or a UV-curable material. As the adhesive layer 112, it can also be patterned into any shape using a UV-curable material.

[0057] Figure 7 as well as Figure 8 This diagram illustrates the process of forming a light-shielding layer 114 on the adhesive layer 112. Figure 7 This is a top view of substrate 101. Figure 8 This is a cross-sectional view of the display area 102. The light-shielding layer 114 is formed not only in the display area 102 but also in the surrounding area 103. As described above, the thickness of the light-shielding layer 114 is determined according to the height of the LED chip 120.

[0058] like Figure 7 As shown, the light-shielding layer 114 has multiple openings 115R, 115G, 115B, and 115C. LED chips 120R, 120G, and 120B are then disposed in each of the multiple openings 115R, 115G, and 115B. A pixel circuit 130 is then disposed in the opening 115C. Therefore, the area of ​​the openings 115R, 115G, 115B, and 115C is preferably slightly larger than the area of ​​the LED chip 120 and the pixel circuit 130. For example, the shape of the opening 115R when viewed from above is preferably 1.05 to 1.5 times the shape of the LED chip 120R when viewed from above. The relationship between the LED chips 120G, 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.

[0059] In subsequent processes, a solvent is applied to bond the LED chip 120 and pixel circuit 130 to the substrate 101. However, if the solvent is applied to the surface of the light-shielding layer 114, it is difficult to precisely attach the LED chip 120 and pixel circuit 130 to the interior of the opening 115. Therefore, the surface of the light-shielding layer 114 is preferably hydrophobic. In other words, the surface contact angle of the light-shielding layer 114 is preferably larger than the surface contact angle of the adhesive layer 112 inside the opening 115. For example, the surface contact angle of the light-shielding layer 114 is preferably 85° or greater. The hydrophobic nature of the surface of the light-shielding layer 114 facilitates the application of solvent to the target area during subsequent solvent application.

[0060] As the light-shielding layer 114, its liquid repellency can be improved by incorporating fluorinated compounds into a highly insulating black resin (such as Cardo resin, low molecular weight acrylic resin, etc.). The liquid repellency of the light-shielding layer 114 can be adjusted by utilizing the amount of fluorinated compounds. The more fluorinated compounds, the better the liquid repellency of the light-shielding layer 114. Fluorinated compounds refer to compounds containing fluorine atoms.

[0061] When the light-shielding layer 114 is applied by spraying, a hydrophobic component can also be added to the black resist, for example. The hydrophobic component refers to a fluorinated surfactant. Fluorinated surfactants have the property that, although uniformly mixed in a liquid state, they migrate and segregate to the uppermost layer of the film upon application or drying. Utilizing this property, when a fluorinated surfactant is pre-added to the black resist, if the black resist is applied and allowed to dry, only the upper layer of the light-shielding layer 114 will exhibit improved hydrophobicity.

[0062] Alternatively, after the light-shielding layer 114 is formed, a fluoropolymer resin can be formed on the light-shielding layer 114 by a so-called stripping method. For example, a pattern is formed on the opening 115 using a photoresist. Next, after the fluoropolymer resin is formed on the pattern using the light-shielding layer 114 and the photoresist, the photoresist is removed. Thus, a fluoropolymer resin can also be formed on the light-shielding layer 114.

[0063] Alternatively, after forming an insulating black resin as a light-shielding layer 114, the surface of the light-shielding layer 114 can be subjected to plasma treatment using a gas containing fluorine or a fluorine compound (e.g., CF4). For example, after forming a mask for the opening 115, the light-shielding layer 114 is exposed to an environment in which a fluorine-containing plasma is formed. A fluorine compound is generated on the surface of the light-shielding layer 114 formed from the resin material. As a result, the hydrophobicity of the surface of the light-shielding layer 114 can be improved compared to the surface of the adhesive layer 112 inside the opening 115.

[0064] Figure 9This diagram illustrates the process of applying solvent 117 to the opening 115 of the light-shielding layer 114. Solvent 117 contains a flux activator. For example, the flux activator described in Japanese Patent Application Laid-Open No. 2014-57019 can be used. For example, solvent 117 can be dripped into the opening 115 of the light-shielding layer 114 using an inkjet printer. In addition to inkjet printing, electrostatic dispensing and precision dispenser methods can also be used as methods for applying solvent 117.

[0065] As in Figure 8 As explained in the description, the surface of the light-shielding layer 114 is hydrophobic. Therefore, even if the solvent 117 is applied to the surface of the light-shielding layer 114, the solvent 117 can be repelled by the surface of the light-shielding layer 114, thereby allowing the solvent 117 to be selectively disposed inside the opening 115.

[0066] Figure 10 This diagram illustrates the process of mounting LED chips 120R, 120G, 120B, and pixel circuit 130 within multiple openings 115 of the light-shielding layer 114. In this embodiment, a solvent 117 is selectively provided inside the multiple openings 115. After picking up the LED chip 120 from the component substrate, the LED chip 120 is released onto the solvent 117 and allowed to fall. The release timing is also the timing at which the lower surface of the LED chip 120 contacts the solvent 117. At this time, the solvent 117 and the LED chip 120 are in contact, allowing the LED chip 120 to move smoothly on the solvent 117. During operations such as holding, transferring, and releasing the LED chip 120, a device (e.g., a chip mounter) capable of adsorbing the upper surface of the LED chip 120 and releasing it as needed is used. Alternatively, a transfer substrate can be used to pick up multiple LED chips from a component substrate. After the transfer substrate is bonded to the circuit board, the LED chips 120 are separated from the carrier substrate, thereby placing the LED chips 120 in the opening 115. Furthermore, the pixel circuit 130 is also placed on the solvent 117 in the same manner as the LED chips 120.

[0067] The LED chip 120, placed on the solvent 117, oscillates in position with the movement of the solvent 117 over a period of time. After a certain period, the shape of the solvent 117 stabilizes, causing the position of the LED chip 120 to converge to a predetermined position. Here, the opening 115 of the light-shielding layer 114 on which the solvent 117 is disposed is the area that projects the shape of each LED chip 120, as described above. Therefore, the convergence position of each LED chip 120 is approximately consistent with the opening 115. In this way, by forming the solvent 117 in the opening 115, the position of each LED chip 120 can be spontaneously and accurately determined by utilizing the surface tension of the solvent 117.

[0068] As described above, by positioning the LED chip 120 and the pixel circuit 130, positional shifts when mounting the LED chip 120 or the pixel circuit 130 on the substrate 101 can be suppressed. This improves the positional accuracy of the LED chip 120R, LED chip 120G, LED chip 120B, and pixel circuit 130.

[0069] Figure 11 This diagram illustrates the process of drying solvent 117. The drying process, for example, involves heating substrate 101 at approximately 100°C to evaporate solvent 117. As a result, flux activator remains between adhesive layer 112 and LED chip 120, and between adhesive layer 112 and pixel circuit 130. This allows LED chips 120R, 120G, 120B, and pixel circuit 130 to be fixed to adhesive layer 112. Furthermore, in this embodiment, the heights of LED chip 120R, LED chip 120G, and LED chip 120B are approximately the same.

[0070] Figure 12 This diagram illustrates the 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 area 102 and the peripheral area 103. For example, organic resin materials such as acrylic, polyimide, polyamide, and epoxy are used as the insulating layer 116. The thickness of the insulating layer 116 is sufficient to cover the LED chips 120R, 120G, 120B, and the pixel circuit 130, for example, set to 5μm or more and 17μm or less. Next, in the display area 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 area 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 drain electrode 148-2. The depth of the contact holes formed in the display area 102 is different from the depth of the contact holes formed in the peripheral area 103. Therefore, it is preferable that the formation of the contact holes in the display area 102 and the formation of the contact holes in the surrounding area 103 are performed in different processes. Furthermore, in this embodiment, the case where the opening 153 is pre-formed in the insulating layer 152 is described, but this embodiment of the invention is not limited to this. The contact holes may also be formed simultaneously when etching the insulating layer 116, the light-shielding layer 114, the adhesive layer 112, and the insulating layer 152.

[0071] Finally, wiring 118 is formed on the insulating layer 116. For example, a metal such as aluminum or copper is used as wiring 118. Wiring 118 is formed by forming a conductive film on the insulating layer 116 and appropriately patterning it. This allows the LED chip 120 to be connected to the pixel circuit 130. Furthermore, the pixel circuit 130 can be connected to the driving circuit.

[0072] Through the above processes, a display device 100 according to an embodiment of the present invention can be manufactured.

[0073] In this embodiment, Figure 12 The illustrated process describes the formation of contact holes in the insulating layer 116, the light-shielding layer 114, and the adhesive layer 112 in the peripheral region 103, exposing the source electrode or drain electrode 148-2. However, one embodiment of the present invention is not limited to this. For example, it is also possible to... Figure 7 as well as Figure 8 In the process shown, an opening is formed in the light-shielding layer 114 in the peripheral area 103. Figure 12 In the process shown, a contact hole is formed in the opening to expose the source electrode or drain electrode 148-2.

[0074] In a method for manufacturing a display device 100 according to one embodiment of the present invention, the surface of the light-shielding layer is made hydrophobic to repel the solvent 117 coated on the surface of the light-shielding layer. This allows the solvent 117 to be precisely positioned within the opening of the light-shielding layer. After the LED chip 120 and pixel circuit 130 are positioned on the solvent 117, the positions of the LED chip and pixel circuit are concentrated at predetermined positions as the shape of the solvent 117 stabilizes. This allows for precise positioning of the LED chip 120 and pixel circuit 130 in a short time. As explained above, the manufacturing method for the display device 100 improves the manufacturing cycle time for aligning the LED chip and pixel circuit onto the substrate.

[0075] Furthermore, in this embodiment, an example of a circuit composed of transistors 150 is described as a row driver 106 or a column driver 108, but this embodiment of the present invention is not limited to this. As the row driver 106 and the column driver 108, bare chips 140 such as unpackaged integrated circuit substrates, like semiconductor substrates, may also be used.

[0076] Figure 13This is a cross-sectional view of the peripheral area 103 and the display area 102 when a bare chip 140 is used as a row driver 106. When bare chips 140 are used in both 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. A bare chip 140 is disposed in the opening 115D. A plurality of terminals 142-1 to 142-3 are provided on the bare chip 140. Wiring 118-9 connects terminals 142-1 of the bare chip 140 to the pixel circuit 130 of the pixel 110. Wiring 118-10 connects terminals 142-2 of the bare chip 140 to terminals of the bare chip 140 of the adjacent row driver 106. Wiring 118-11 connects terminals 142-3 of the bare chip 140 to terminals of the controller 104.

[0077] When bare chips 140 are used in both row driver 106 and column driver 108, it is not necessary to form transistors on substrate 101. Furthermore, when bare chips are used in both row driver 106 and column driver 108, insulating layers 144 and 152 can be omitted, and adhesive layer 112 can be formed on substrate 101. When multiple openings 115R, 115G, 115B, and 115C are formed in light-shielding layer 114, only opening 115D for arranging the bare chip 140 needs to be formed. Subsequent processes can then be performed in conjunction with... Figures 9-11 The manufacturing process of the display area 102 described herein is carried out in the same manner, thereby simplifying the manufacturing process of the display device 100.

[0078] (Second Implementation)

[0079] In the first embodiment, it was described that the heights of LED chip 120R, LED chip 120G, and LED chip 120B are approximately the same, but this embodiment of the present invention is not limited to this. The heights of LED chip 120R, LED chip 120G, and LED chip 120B sometimes differ for each color. The heights of LED chips 120R, 120G, and 120B sometimes differ by about 8μm to 12μm due to differences in construction, etc. Because the heights of LED chips 120R, 120G, and 120B are different, the connection surfaces of terminals 122-1 and 122-2 with wiring 118 become different. In addition, the depth of the contact holes formed in the insulating layer 116 differs between the terminals of the shorter and taller LED chips 120. Therefore, there are concerns that it may be difficult to form contact holes in the insulating layer 116 corresponding to the height of the LED chip 120, or that wiring may break when wiring 118 is formed.

[0080] Therefore, when the heights of LED chips 120R, 120G, and 120B are different for each color, it is preferable to adjust the thickness of the adhesive layer 112 so that the connection surfaces of terminals 122-1 and 122-2 are the same as those of wiring 118.

[0081] <Composition of the display device>

[0082] Figure 14 This is a cross-sectional view of a pixel 110 in a display device 100A according to an embodiment of the present invention. Figure 14 Corresponding to the cross-section of pixel 110, but for ease of explanation, it is... Figure 14 The cross-sectional schematic diagram shown is not consistent with Figure 2 The top view corresponding to pixel 110 is shown.

[0083] In this embodiment, such as Figure 14 As shown, the height of the LED chips will increase sequentially from LED chip 120B, LED chip 120R, to LED chip 120G. In this case, the thickness of the adhesive layer 112 in the area where LED chips 120R, 120G, and 120B are disposed is adjusted so that the terminals in LED chips 120R, 120G, and 120B are the same as the connection surface of the wiring 118. Figure 14 In this design, the thickness of the adhesive layer 112 inside the opening 115R for LED chip 120R is set to thickness t1. The thickness of the adhesive layer 112 inside the opening 115G for LED chip 120G is set to thickness t2. The thickness of the adhesive layer 112 inside the opening 115B for LED chip 120B is set to thickness t3. The thickness of the adhesive layer 112 overlapping with the light-shielding layer 114 is set to thickness t4. The thickness of the adhesive layer 112 inside the opening 115C for pixel circuit 130 is set to thickness t5.

[0084] As described above, in this embodiment, the height increases in the order of LED chips 120B, 120R, and 120G. Therefore, the thickness of the adhesive layer 112 is adjusted so that the thickness increases in the order of thickness t2, thickness t1, and thickness t3. Furthermore, depending on the height of the LED chip 120G, thickness t2 and thickness t4 can be the same, or thickness t2 can be greater than thickness t4. Figure 14The diagram shows a case where thickness t5 is greater than thickness t3, but thickness t5 can also be appropriately set according to the height of pixel circuit 130. Therefore, when the height of the terminals of pixel circuit 130 differs from the height of LED chips 120R, 120G, and 120B, the thicknesses t1 to t5 can be adjusted. This allows the terminals of LED chips 120R, 120G, 120B, and pixel circuit 130 to have the same connection surface as wiring 118.

[0085] <Manufacturing Method of Display Device>

[0086] Reference Figure 4 , Figure 5 , Figures 9-12 , Figures 15-17 ,right Figure 14 The manufacturing method of the display device 100A shown will be described. Furthermore, detailed descriptions of processes identical to those in the first embodiment will be omitted.

[0087] The process of forming transistor 150 and insulating layer 152 on substrate 101 and Figure 4 The procedures shown are the same.

[0088] In this embodiment, in order to adjust the thickness of the adhesive layer 112 inside the openings 115R, 115G, 115B, and 115C, an adhesive photoresist is used as the adhesive layer 112, for example. As the adhesive photoresist, VPA (vinyl sulfonic acid) type adhesive layers described above can be used, for example.

[0089] First, with Figure 5 The process is the same as shown, forming an adhesive layer 112 of the same thickness on the insulating layer 152. Next, as... Figure 15 As shown, adhesive layers 112a, 112b, and 112c are formed locally. Region 113a, where adhesive layer 112a is formed, is the area where the LED chip 120R is disposed; region 113b, where adhesive layer 112b is formed, is the area where the LED chip 120B is disposed; and region 113c, where adhesive layer 112c is formed, is the area where the pixel circuit 130 is disposed. Furthermore, in Figure 15 In the process, the thickness increases in the order of adhesive layer 112a, adhesive layer 112b, and adhesive layer 112c. The thickness of adhesive layers 112a, 112b, and 112c varies depending on the height of the subsequently mounted LED chips 120R, 120G, 120B, and pixel circuit 130. The remaining area is where the light-shielding layer 114 and the LED chip 120G are disposed. As adhesive layer 112, by using a photoresist with adhesive properties, adhesive layers 112 of varying thicknesses can be formed in a defined area. Alternatively, adhesive layers can be locally formed in the area where the LED chip 120G is disposed, as needed.

[0090] Regarding the method for forming adhesive layers 112 of varying thicknesses, for example, adhesive layers are formed with a predetermined thickness in regions 113a, 113b, and 113c respectively; next, adhesive layers are formed with a predetermined thickness in regions 113b and 113c respectively; finally, an adhesive layer with a predetermined film thickness is formed in region 113c. Thus, an adhesive layer 112 having adhesive layers 112a, 112b, and 112c can be formed.

[0091] Figure 16 This diagram illustrates the process of forming a light-shielding layer 114 on the adhesive layer 112. (See diagram for example.) Figure 16 As shown, the thickness of the light-shielding layer 114 is preferably greater than the thickness of the adhesive layer 112c, which has the thickest film among the adhesive layers 112a, 112b, and 112c. This is because if the thickness of the light-shielding layer 114 is thinner than the thickness of the adhesive layer 112c, the solvent 117 will overflow from the opening 115 of the light-shielding layer 114.

[0092] Regarding the process of setting the LED chip 120 and pixel circuit 130 on the adhesive layer 112, and... Figures 9-11 The explanation is the same as in the previous text, so detailed explanations are omitted.

[0093] Figure 17 This diagram illustrates the 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 area 102 and the surrounding area 103. Regarding the material and thickness of the insulating layer 116, see [link to diagram]. Figure 12 As explained below. Next, contact holes are formed in the insulating layer 116. This exposes terminals 122R-1, 122R-2, 122G-1, 122G-2, 122B-1, 122B-2, 132-1, and 132-2 from the insulating layer 116. Additionally, wiring or terminals of the driving circuit are exposed from the insulating layer 116. Finally, wiring 118-1 to 118-8 are formed on the insulating layer 116. Wiring 118-1 to 118-8 are formed by forming a conductive film on the insulating layer 116 and appropriately patterning it. This allows the LED chip 120 to be connected to the pixel circuit 130 via wiring 118. Furthermore, the pixel circuit 130 can be connected to the driving circuit via wiring 118.

[0094] Through the above processes, it is possible to manufacture Figure 14 The display device 100A shown is an embodiment of the present invention.

[0095] According to the display device 100A of this embodiment, even when the heights of LED chip 120R, LED chip 120G, and LED chip 120B are different for each color, the connection surfaces of terminals 122-1 and 122-2 with the wiring 118 can be made the same. Therefore, regardless of the height of the LED chip 120, the depth of the contact holes formed in the insulating layer 116 can be made approximately the same. Consequently, it is easy to form contact holes in the insulating layer 116, and wiring breakage during the formation of the wiring 118 can be suppressed.

[0096] As embodiments of the present invention, the above-described embodiments can be appropriately combined to implement them as long as they do not contradict each other. Furthermore, structures obtained by adding, deleting, or designing constituent elements based on the display devices of each embodiment, or processes obtained by adding, omitting, or changing conditions, are also included within the scope of the present invention as long as they capture the spirit of the invention.

[0097] Even if other effects differ from those achieved by the various embodiments described above, effects that are obvious from the description in this specification or that can be easily predicted by those skilled in the art can of course be understood as being brought about by the present invention.

[0098] Explanation of reference numerals in the attached figures

[0099] 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 chips; 122R-1, 122R-2, 122G-1, 122G-2, 122B-1, 122B-2: Terminals; 124: Photoresist; 130: Pixel circuit; 142: Gate electrode; 144: Insulating layer; 146: Semiconductor layer; 148-1, 148-2: Source or drain electrode; 150: Transistor.

Claims

1. A display device, wherein, have: A substrate equipped with a driving circuit; An adhesive layer covering the substrate; A first LED chip disposed on the adhesive layer; The pixel circuit is disposed separately from the first LED chip on the adhesive layer; A light-shielding layer is disposed on the adhesive layer and has a first opening and a second opening. The shape of the first opening is approximately the same as the shape of the first LED chip when viewed from above, and the shape of the second opening is approximately the same as the shape of the pixel circuit when viewed from above. An insulating layer covers the driving circuit and the pixel circuit; as well as A first wiring, disposed on the insulating layer, connects the first LED chip to the pixel circuit. The first wiring overlaps with the light-shielding layer.

2. The display device according to claim 1, wherein, It also has a second wiring, which is disposed on the insulating layer and electrically connects the pixel circuit to the driving circuit; The first LED chip and the pixel circuit are located in the display area. The driving circuit is located in the peripheral area surrounding the display area. The second wiring is electrically connected to the drive circuit in the peripheral region via a contact hole provided in the insulating layer.

3. The display device according to claim 2, wherein, The height of the pixel circuit is different from the height of the first LED chip. In the adhesive layer, the thickness of the first region configured for the first LED chip is different from the thickness of the second region configured for the pixel circuit.

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

5. The display device according to claim 2, wherein, It also has: A second LED chip is disposed on the adhesive layer in the display area, and its luminous color is different from that of the first LED chip. as well as A third wiring, disposed on the insulating layer, connects the second LED chip to the pixel circuit. The light-shielding layer also has a third opening with a shape that is approximately the same as the shape when the second LED chip is viewed from above.

6. The display device according to claim 5, wherein, The height of the second LED chip is different from the height of the first LED chip. In the adhesive layer, the thickness of the first region configured for the first LED chip is different from the thickness of the third region configured for the second LED chip.

7. The display device according to claim 6, wherein, The height of the connection surface in the first LED chip that is connected to the first wiring is the same as the height of the connection surface in 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 contains fluorine or fluorine compounds.

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

10. A method for manufacturing a display device, wherein, Includes the following steps: An adhesive layer is formed on a substrate containing a driving circuit. A light-shielding layer is formed on the adhesive layer. This light-shielding layer has multiple openings and a hydrophobic surface. Solvent is selectively applied to the adhesive layer within the plurality of openings. The first LED chip is placed in contact with the solvent in the first of the plurality of openings. The pixel circuit is mounted in such a manner that it is in contact with the solvent in the second of the plurality of openings. The solvent is evaporated to bond the adhesive layer to the first LED chip and to the pixel circuit. An insulating layer is formed on the driving circuit, the first LED chip, and the pixel circuit. A first contact hole leading to the first LED chip and a second contact hole leading to the pixel circuit are formed in the insulating layer. A first wiring is formed on the insulating layer, which connects the first LED chip to the pixel circuit via the first contact hole and the second contact hole.

11. The method of manufacturing a display device according to claim 10, wherein, The height of the first LED chip is different from the height of the pixel circuit. In the step of forming the adhesive layer, the adhesive layer is formed such that the thickness in the first region where the first LED chip is disposed is different from the thickness in the second region where the pixel circuit is disposed.

12. The method of manufacturing a display device according to claim 10, wherein, After mounting the first LED chip, the following steps are also included: The second LED chip is placed in contact with the solvent in the third of the plurality of openings. The solvent is evaporated to bond the adhesive layer to the second LED chip.

13. The method of manufacturing a display device according to claim 12, wherein, The height of the first LED chip is different from the height of the second LED chip. The steps for forming the adhesive layer include: The adhesive layer is formed such that its thickness in the first region where the first LED chip is disposed is different from its thickness in the third region where the second LED chip is disposed.

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

15. The method of manufacturing a display device according to claim 10, wherein, The steps of forming the light-shielding layer having the said hydrophobicity include: After forming an insulating black resin on the adhesive layer, plasma treatment is performed using a gas containing fluorine or a fluorine compound.

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