Display device

Abstract

The present invention addresses the problems of insulating films for the insulation of peripheral wires, protective films, partition walls, and the like absorbing light, the light-extraction efficiency of a display being reduced, and luminance being made insufficient due to LED display devices emitting light in all directions.　This display device comprises at least wires, a cured film, and a plurality of light-emitting elements, wherein: each of the light-emitting elements has electrodes on two different surfaces thereof; at least one of the electrodes is connected to a plurality of wires extending in the cured film; the plurality of wires are configured to maintain electrical insulating properties due to the cured film; the cured film is obtained by curing a resin composition containing a resin (A); the transmittance of the cured film with respect to light having a wavelength of 450 nm is 80-100% on the basis of a thickness of 5 μm of the cured film.

Description

display device

[0001] The present invention relates to a display device such as an LED display.

[0002] In recent years, in order to further improve the performance of displays, LED displays, which are constructed by arranging light-emitting diodes (LEDs) in the same number as the number of pixels, have been attracting attention as a new display technology following liquid crystal displays, plasma displays, and organic electroluminescent (EL) displays. In particular, mini-LED displays, which have reduced the size of the LEDs serving as light sources from the conventional approximately 1 mm to 100-700 μm, and micro-LED displays, which have been miniaturized to less than 100 μm, have been attracting attention and are the subject of active research and development. Key features of mini-LED displays and micro-LED displays include high contrast, fast response, low power consumption, and a wide viewing angle. They are expected to be used not only in traditional wearable displays such as televisions, smartphones, and smartwatches, but also in a wide range of promising new applications such as signage, AR, VR, and even transparent displays capable of displaying spatial images.

[0003] Various configurations have been proposed for LED display devices aimed at practical application and high performance, including a configuration in which micro LEDs are arranged on a multilayer flexible circuit board (see Patent Document 1), a configuration in which a bank layer and trace lines are provided on a display substrate, and micro LEDs and a micro driver chip are arranged on the bank layer and trace lines (see Patent Document 2), and a configuration in which a planarizing film is formed on a growth substrate on which a light emitting element body having electrode pads is integrally formed, the planarizing film on the electrode pads is removed to expose the electrode pads, and outer electrode pads connected to the electrode pads are formed on the planarizing film, and the outer electrode pads are arranged opposite the circuit side electrode portions formed on a circuit board, thereby electrically connecting the front external electrode pads to the circuit side electrode portions (see Patent Document 3).

[0004] JP 2019-153812 A JP 2020-52404 A JP 2020-68313 A

[0005] However, the LED display device described in the above document generates light in all directions, and therefore the light is absorbed by the surrounding insulating films for insulating wiring, protective films, partitions, etc., resulting in low light extraction efficiency as a display and insufficient brightness.

[0006] In order to solve the above problems, the present invention has the following configuration.

[0007] [1] A display device having at least wiring, a cured film, and a plurality of light-emitting elements, wherein the light-emitting elements each have an electrode on two different surfaces, at least one of the electrodes is connected to a plurality of wirings extending in the cured film, and the plurality of wirings are configured to maintain electrical insulation by the cured film, the cured film is a film obtained by curing a resin composition containing (A) resin, and the transmittance of light with a wavelength of 450 nm at a standard thickness of 5 μm is 80% or more and 100% or less.

[0008] [2] The display device according to [1], wherein the cured film has a total thickness of 5 μm or more and 100 μm or less.

[0009] [3] The display device according to [1] or [2], wherein the number of layers of the cured film is 2 to 10.

[0010] [4] The display device according to any one of [1] to [3], wherein the cured film has an opening pattern penetrating through it in the thickness direction, the wiring is arranged at least in the opening pattern, and the longest length of the bottom surface of the wiring formed at a position in contact with the light-emitting element is 2 μm or more and 20 μm or less.

[0011] [5] The display device according to any one of [1] to [4], wherein the cured film covers a surface other than the light extraction surface of the light-emitting element.

[0012] [6] A display device having at least a substrate having wiring and / or TFTs, a cured film, and a plurality of light-emitting elements, wherein the light-emitting elements each have electrodes on two different surfaces, at least a portion of the wiring and / or TFTs is in contact with the cured film, the cured film is a film obtained by curing a resin composition containing (A) resin, and the transmittance of the cured film at a thickness of 5 μm for light with a wavelength of 450 nm is 80% or more and 100% or less.

[0013] [7] The display device according to any one of [1] to [6], wherein a reflective film is further provided on the cured film.

[0014] [8] The display device according to any one of [1] to [7], wherein a partition wall having a thickness equal to or greater than the thickness of the light-emitting element is disposed between the plurality of light-emitting elements.

[0015] [9] The display device according to any one of [1] to [8], wherein a partition wall having a thickness equal to or greater than the thickness of the light-emitting element is disposed between the plurality of light-emitting elements in the cured film covering the light-emitting element.

[0016]

[10] The display device according to any one of [1] to [9], wherein the light-emitting element is an LED having a side length of 5 μm or more and 700 μm or less.

[0017]

[11] The display device according to any one of [1] to

[10] , further comprising a driving element and a substrate, the driving element being connected to the light-emitting element through wiring, and at least a portion of the wiring extending to a side surface of the substrate.

[0018]

[12] The display device according to any one of [1] to

[11] , further comprising a light-shielding layer between the plurality of light-emitting elements.

[0019]

[13] The display device according to any one of [1] to

[12] , wherein the resin (A) contains one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof.

[0020]

[14] The display device according to any one of [1] to

[13] , wherein the resin composition containing the resin (A) further contains a photosensitizer (B).

[0021]

[15] The display device according to any one of [1] to

[14] , wherein the resin composition containing the resin (A) further contains a thermal crosslinking agent (C).

[0022]

[16] The display device according to any one of [1] to

[15] , wherein the resin composition containing the resin (A) is positive photosensitive.

[0023] The display device of the present invention has high light extraction efficiency and can provide a display device with sufficient brightness.

[0024] 1 is a cross-sectional view taken along a plane perpendicular to the counter substrate, showing an example of a first embodiment of the display device of the present invention; FIG. 2 is a cross-sectional view taken along a plane perpendicular to the counter substrate, showing another example of the first embodiment of the display device of the present invention; FIG. 3 is an enlarged cross-sectional view (a) of a designated region A, and a bottom view (b) of the designated region A excluding the light-emitting elements, as viewed from the counter substrate side; FIG. 4 is a cross-sectional view (a) of the light-emitting element driving substrate side of the designated region B cut along a plane parallel to the counter substrate, FIG. 5 is a cross-sectional view (b) of the designated region B at a position not including wiring perpendicular to the counter substrate, and FIG. 6 is a bottom view (c) of the designated region B excluding the counter substrate, as viewed from the counter substrate side; FIG. 6 is a cross-sectional view taken along a plane perpendicular to the counter substrate, showing an embodiment of the display device of the present invention, having a configuration in which a reflective film is provided; FIG. 7 is a cross-sectional view taken along a plane perpendicular to the counter substrate, showing an embodiment of the display device of the present invention, having a configuration in which partition walls are provided; FIG. 8 is a cross-sectional view taken along a plane perpendicular to the counter substrate, showing an embodiment of the display device of the present invention, having a configuration in which partition walls are provided in the cured film; FIG. 1 is a cross-sectional view taken along a plane perpendicular to the counter substrate, showing one embodiment of a display device of the present invention, having a configuration in which a partition wall is provided in a cured film and a reflective film is provided thereon. FIG. 1 is a cross-sectional view taken along a plane perpendicular to the counter substrate, showing one embodiment of a display device of the present invention, having a configuration in which a driving element is provided in a cured film. FIG. 1 is a cross-sectional view taken along a plane perpendicular to the support substrate or the counter substrate, showing a manufacturing process of one embodiment of a display device of the present invention. FIG. 1 is a cross-sectional view taken along a plane perpendicular to the support substrate, showing a manufacturing process of one embodiment of a display device of the present invention, having a configuration in which a partition wall is provided. FIG. 1 is a cross-sectional view taken along a plane perpendicular to the support substrate, showing a manufacturing process of one embodiment of a display device of the present invention, having a configuration in which a reflective film is provided. FIG. 1 is a cross-sectional view taken along a plane perpendicular to the support substrate or the counter substrate, showing another example of a manufacturing process of a display device of the present invention, having a configuration in which a partition wall is provided. FIG. 1 is a cross-sectional view taken along a plane perpendicular to the support substrate, showing another example of a manufacturing process of a display device of the present invention, having a configuration in which a reflective film is provided. FIG. 2 is a cross-sectional view taken along a plane perpendicular to the support substrate, showing another example of a manufacturing process of a display device of the present invention, having a configuration in which a partition wall is provided. 10 is a cross-sectional view of a display device according to another embodiment of the present invention taken along a plane perpendicular to the counter substrate, and FIG. 11 is a cross-sectional view of a display device according to another embodiment of the present invention taken along a plane perpendicular to the counter substrate.1 is a cross-sectional view taken along a plane perpendicular to the counter substrate showing another embodiment of the display device of the present invention; FIG. 1 is a cross-sectional view taken along a plane perpendicular to the counter substrate showing an embodiment of the display device of the present invention having a configuration in which a light-shielding layer is provided; FIG. 2 is a cross-sectional view taken along a plane perpendicular to the support substrate showing an opening pattern of a cured film; FIG. 3 is a cross-sectional view taken along a plane perpendicular to the support substrate showing a manufacturing process of an embodiment of the display device of the present invention having a configuration in which a light-shielding layer is provided; FIG. 4 is a cross-sectional view taken along a plane perpendicular to the light-emitting element drive substrate showing an example of a manufacturing process of a display device according to the second embodiment of the present invention; FIG. 5 is a cross-sectional view taken along a plane perpendicular to the counter substrate showing another embodiment of the display device of the present invention using light-emitting elements; FIG. 6 is a cross-sectional view taken along a plane perpendicular to the counter substrate showing an embodiment of the display device of the present invention using light-emitting elements having a different connection mode; FIG. 7 is a cross-sectional view taken along a plane perpendicular to the counter substrate showing an embodiment of the display device of the present invention using light-emitting elements having a different connection mode; FIG. 8 is a cross-sectional view taken along a plane perpendicular to the counter substrate showing an embodiment of the display device of the present invention using light-emitting elements having a different connection mode; 1 is a cross-sectional view taken along a plane perpendicular to the element driving substrate, showing another example of the second embodiment of the display device of the present invention; 2 is a cross-sectional view taken along a plane perpendicular to the support substrate, showing another example of the second embodiment of the display device of the present invention, using light-emitting elements of a different connection mode; 3 is a cross-sectional view taken along a plane perpendicular to the light-emitting element driving substrate, showing an example of a manufacturing process of the display device according to the second embodiment of the present invention;

[0025] Preferred embodiments of the display device of the present invention will be specifically described below, but the present invention is not limited to the following embodiments and can be modified and implemented in various ways depending on the purpose and application.

[0026] A first aspect of the display device of the present invention is a display device having at least wiring, a cured film, and a plurality of light-emitting elements, wherein the light-emitting elements each have an electrode on two different surfaces, at least one of the electrodes is connected to a plurality of wirings extending in the cured film, and the plurality of wirings maintain electrical insulation due to the cured film, and the cured film is a film obtained by curing a resin composition containing (A) resin, and the transmittance of light with a wavelength of 450 nm at a standard thickness of 5 μm is 80% or more and 100% or less.

[0027] In the following description, unless otherwise specified, the first aspect or the second aspect described below is a description common to both aspects.

[0028] The display device according to the first embodiment of the present invention will be described with reference to FIG. 1 as an example.

[0029] In FIG. 1 , the display device 1 has a plurality of light-emitting elements 2 arranged on an opposing substrate 5, and a cured film 3 arranged on the light-emitting elements 2. Here, the light-emitting elements have a polyhedral three-dimensional shape. A polyhedral three-dimensional shape is a three-dimensional shape having multiple faces, preferably having at least one pair of parallel faces. Examples include tetrahedrons, hexahedrons such as rectangular parallelepipeds and cubes, and octahedrons. However, the polyhedral three-dimensional shape is not limited to such regular shapes, and also includes shapes in which the vertices or edges of these shapes are chamfered, and shapes based on these shapes that have recesses, grooves, or steps. Here, a deviation of plus or minus 5° is considered parallel, and the parallel faces or other faces may have irregularities. The light-emitting element has electrodes on two different faces. "Having electrodes on two different faces" means that, in a polyhedral three-dimensional light-emitting element, when one of the faces having an electrode is considered a reference face, the other electrodes are located on a face other than the reference face. Here, the reference surface refers to a surface of a continuous range within the polyhedral three-dimensional shape, and a surface that exists in the same spatial plane but is divided by a groove within the polyhedral three-dimensional shape is considered to be a surface different from the reference surface. Furthermore, when focusing on one light-emitting element, the electrodes provided on the two different surfaces are sometimes referred to as a pair of electrodes.

[0030] In the present invention, the electrodes provided on the light-emitting elements refer to connection sites for transmitting signals for controlling the light emission of the light-emitting elements from wiring to the light-emitting elements. In the embodiment shown in Figure 1, when focusing on one light-emitting element, the light-emitting element has a polyhedral three-dimensional shape, with one electrode on the surface connected to the wiring 4 extending in the cured film 3, and the other electrode on the surface facing the opposing substrate. When viewed as a whole, one electrode of the pair of electrodes provided on each of the plurality of light-emitting elements is connected to each of the plurality of wirings 4 extending in the cured film 3.

[0031] 1 illustrates a configuration in which a total of three layers are laminated by laminating multiple cured films 3 on the cured film 3 arranged so as to be in contact with at least a portion of the light-emitting element 2, but the cured film 3 may also be a single layer. The light-emitting element 2 has electrodes 6 on two different surfaces, and one of the pair of electrodes 6 is connected to a wiring 4 extending in the cured film 3. The multiple wirings 4 extending in the cured film 3 are separated by the cured film 3. With this structure, the multiple wirings 4 maintain electrical insulation due to the cured film 3. The cured film 3 is preferably a cured film obtained by curing a resin composition containing the (A) resin described below.

[0032] Of the pair of electrodes 6, the electrode 6 that is not connected to the wiring 4 extending in the cured film 3 is connected to the wiring 4d. The wiring 4d may be formed on a support substrate described below, or may be formed on the opposing substrate 5. When forming the wiring 4d on the support substrate, the wiring 4d may be formed after forming a temporary attachment layer made of a temporary attachment material on the support substrate. The electrode 6 and the wiring 4d may be connected via a bump, a conductive film, or the like, or may be connected directly.

[0033] The wiring 4d may be covered with the cured film 3 to maintain electrical insulation, or the cured film 3 and the wiring 4d may form a laminated structure of two or more layers. The wiring 4d may be connected to the wiring 4 extending in the cured film 3 arranged so as to contact at least a portion of the light-emitting element 2 via a through-electrode or the like, or may be arranged on the side of the light-emitting element 2 or the side of the partition wall 16 described below and connected to the wiring 4 extending in the cured film 3, or may be connected to the light-emitting element drive substrate 7. Furthermore, the light-emitting element 2 is electrically connected to a drive element 8 attached to the light-emitting element drive substrate 7 provided in a position opposite the counter substrate 5 through the wiring 4 or 4c, thereby controlling the light emission of the light-emitting element 2. The light-emitting element drive substrate 7 is also electrically connected to the wiring 4 via, for example, a bump 10. Furthermore, a barrier metal 9 may be provided to prevent diffusion of metal such as the wiring 4. Note that, hereinafter, the wiring 4c in the figures may be formed on the side of the light-emitting element drive substrate 7, may penetrate the light-emitting element drive substrate 7, or may be connected to the drive element 8 as a wiring constituting the light-emitting element drive substrate.

[0034] 1 illustrates an example in which wiring 4d and an electrode 6 are disposed between the counter substrate 5 and the light-emitting element 2, and further, a cured film 3 is disposed between the counter substrate 5 and the light-emitting element 2 so as to be adjacent to the wiring 4 and the electrode 6. However, this embodiment also includes a configuration in which the wiring 4 and the electrode 6 are formed so as to cover the entire flat surface of the light-emitting element 2, and the cured film 3 is not disposed between the counter substrate 5 and the light-emitting element 2, or a configuration in which the wiring 4 and the electrode 6 shown in FIG. 1 are formed as thin films, in which a resin film 21 described later cannot reach adjacent to the wiring 4 and the electrode 6, and the cured film 3 is not formed between the counter substrate 5 and the light-emitting element 2, resulting in a partial cavity.

[0035] It is important that the cured film 3 has a light transmittance of 80% or more and 100% or less at a wavelength of 450 nm when the cured film 3 has a thickness of 5 μm. This prevents light emitted in all directions from the light-emitting element 2 from being absorbed in the cured film 3, thereby increasing the light extraction efficiency and improving brightness. From the viewpoint of improving brightness, the light transmittance at a wavelength of 450 nm when the cured film 3 has a thickness of 5 μm is more preferably 90% or more and 100% or less.

[0036] The light transmittance at a wavelength of 450 nm when the cured film has a standard thickness of 5 μm may be measured by peeling off the cured film from the display device, or the light transmittance may be measured for a cured film prepared under the conditions of the method for evaluating the light transmittance of a cured film described below. Furthermore, when a multilayer cured film is formed, any of the cured films may be used for the measurement. If the thickness of the cured film is not 5 μm, the measured transmission spectrum may be converted into a film thickness of 5 μm according to Lambert's law.

[0037] The materials for the wirings 4, 4c, 4d and the electrodes 6 are not particularly limited, and include metals and conductive films, and known materials may also be used.

[0038] Metals are preferred from the viewpoint of electron mobility, and examples thereof include gold, silver, copper, aluminum, nickel, titanium, molybdenum, and alloys containing these.

[0039] These metals can be formed by wet plating such as electroless plating and electrolytic plating, CVD chemical vapor deposition (CVD) methods such as thermal CVD, plasma CVD and laser CVD, dry plating methods such as vacuum deposition, sputtering and ion plating, and methods in which a metal foil is bonded to a substrate and then etched.

[0040] The conductive film is preferable from the viewpoint of transparency, etc., and examples thereof include a compound containing an oxide of at least one element selected from the group consisting of indium, gallium, zinc, tin, titanium, and niobium as a main component, and a photosensitive conductive paste containing an organic substance and conductive particles, but other known conductive films may also be used. Specific examples of compounds containing an oxide of at least one element selected from the group consisting of indium, gallium, zinc, tin, titanium, and niobium as a main component include indium tin zinc oxide (ITZO), indium gallium zinc oxide (IGZO: InGaZnO), zinc oxide (ZnO), indium zinc oxide (IZO), indium gallium oxide (IGO), indium tin oxide (ITO), and indium oxide (InO).

[0041] These conductive films can be formed by, for example, wet plating such as electroless plating and electrolytic plating; CVD (chemical vapor deposition) methods such as thermal CVD, plasma CVD and laser CVD; dry plating methods such as vacuum deposition, sputtering and ion plating; or a method in which a metal foil is bonded to a substrate and then etched.

[0042] In a photosensitive conductive paste containing an organic substance and conductive particles, the content of the conductive particles is preferably 60% by mass or more and 90% by mass or less. By including an organic substance in the conductive layer, disconnection at curved surfaces or bent portions can be suppressed, thereby improving conductivity. If the content of the conductive particles is less than 60% by mass, the probability of contact between the conductive particles decreases, resulting in reduced conductivity. Furthermore, the conductive particles tend to separate from each other at bent portions of the wiring. The content of the conductive particles is preferably 70% by mass or more. On the other hand, if the content of the conductive particles exceeds 90% by mass, it becomes difficult to form a wiring pattern and disconnection at bent portions is likely to occur. The content of the conductive particles is preferably 80% by mass or less. Examples of organic substances include epoxy resins, phenoxy resins, acrylic copolymers, and epoxy carboxylate compounds. Two or more of these may be contained. Furthermore, an organic substance having a urethane bond may be contained. By including an organic substance having a urethane bond, the flexibility of the wiring can be improved. Furthermore, the organic substance preferably exhibits photosensitivity, allowing fine wiring patterns to be easily formed by photolithography. The photosensitivity is exhibited by including, for example, a photopolymerization initiator or a component having an unsaturated double bond.

[0043] In the present invention, the conductive particles have an electrical resistivity of 10 －５It refers to particles composed of a substance with a resistivity of Ω·m or less. Examples of materials constituting the conductive particles include silver, gold, copper, platinum, lead, tin, nickel, aluminum, tungsten, molybdenum, chromium, titanium, indium, alloys of these metals, and carbon particles. It is also preferable to contain two or more types of conductive particles. By containing two or more types of conductive particles, sintering of conductive particles of the same type and volumetric shrinkage during the heat treatment step described below is suppressed, resulting in suppression of volumetric shrinkage of the entire conductive film and improved flexibility.

[0044] The average particle diameter of the conductive particles is preferably 0.005 μm or more and 2 μm or less. Here, the average particle diameter refers to the average particle diameter of the larger particles when two or more types of conductive particles are contained. When the average particle diameter of the conductive particles is 0.005 μm or more, the interaction between the conductive particles can be appropriately suppressed, and the dispersed state of the conductive particles can be maintained more stably. The average particle diameter of the conductive particles is more preferably 0.01 μm or more. On the other hand, when the average particle diameter of the conductive particles is 2 μm or less, it becomes easier to form a desired wiring pattern. The average particle diameter of the conductive particles is more preferably 1.5 μm or less.

[0045] The thickness of the conductive film is preferably 2 μm or more and 10 μm or less. When the thickness of the conductive film is 2 μm or more, breakage at the bent portion can be further suppressed and the conductivity can be further improved. The thickness of the conductive film is more preferably 4 μm or more. On the other hand, when the thickness of the conductive film is 10 μm or less, the wiring pattern can be more easily formed in the manufacturing process. The thickness of the conductive film is more preferably 8 μm or less.

[0046] 17 illustrates another embodiment of the present invention, in which a cured film 22 is provided in the display device of FIG. 1 so as to be in contact with at least a portion of the light-emitting element 2. The cured film 22 arranged so as to be in contact with at least a portion of the light-emitting element 2 may be made of a cured film obtained by curing a resin composition containing the (A) resin or a resin sheet, or may be made of a material other than a cured film obtained by curing a resin composition containing the (A) resin or a resin sheet, and known materials such as epoxy resin, silicone resin, and fluororesin may be used.

[0047] In the present invention, the light emitting element driving substrate 7 may be a substrate having elements with a driving function, and preferably has the driving elements 8 connected thereto.

[0048] The light-emitting element driving substrate 7 is not particularly limited, and known substrates can be used. Examples include glass substrates, sapphire substrates, printed wiring boards, TFT array substrates, and ceramics. Wiring may be formed on at least one surface of the glass substrate or sapphire substrate. When a printed wiring board is used, it can be connected to the driving elements 8, bumps 10, wiring 4, etc. without forming wiring 4c.

[0049] In the present invention, the total thickness of the cured film is preferably 5 μm or more and 100 μm or less. By making the total thickness of the cured film 5 μm or more and 100 μm or less, it is possible to suppress absorption of light emitted in all directions from the light-emitting element 2 in the cured film 3, thereby increasing the light extraction efficiency and improving the brightness. Furthermore, it is possible to reduce the height of the display device having the light-emitting element itself, suppress wiring defects such as short circuits in the wiring due to shorter wiring distances, suppress loss, and improve high-speed response.

[0050] The total thickness of the cured film refers to the total thickness of the continuous cured film layer in which at least a portion of one cured film is in contact with another cured film. For example, when a plurality of cured films 3 are stacked as shown in FIG. 1 above, the range indicated by 19 in FIG. 1 is the total thickness of the cured film layer. The total thickness is preferably 5 μm or more and 70 μm or less, more preferably 5 μm or more and 60 μm or less. If it is less than 5 μm, the wiring protection is insufficient, which may cause wiring defects such as wiring short circuits. If it exceeds 100 μm, there is a concern that the light extraction efficiency will be insufficient, and there may be inconveniences in terms of reducing the height of the display device itself, suppressing wiring defects such as wiring short circuits due to shorter wiring distances, suppressing loss reduction, and improving high-speed response.

[0051] When a plurality of cured films are laminated, the number of layers of the cured film is preferably 2 to 10. From the viewpoint of arranging a plurality of light-emitting elements, the cured film preferably has one or more layers, and further, by having two or more layers, the number of wirings that can be connected to the light-emitting elements can be increased, allowing a plurality of light-emitting elements to be arranged, and from the viewpoints of suppressing wiring defects such as short-circuiting of wiring due to a low package height or a short wiring distance, reducing loss, and improving high-speed response, 10 or less layers are preferred.

[0052] In the present invention, the cured film is provided with an opening pattern penetrating through the film in the thickness direction, and the wiring is disposed at least in the opening pattern, and it is preferable that the maximum length of the bottom surface portion of the wiring formed at a position in contact with the light-emitting element is 2 μm or more and 20 μm or less.

[0053] 2 shows an enlarged cross-sectional view (a) of a designated region A in FIG. 1 and a bottom view (b) of the designated region A excluding the light-emitting element, as viewed from the opposing substrate side. In the enlarged cross-sectional view (a) of the designated region A in FIG. 2, a cured film 3 is provided on the light-emitting element 2. An opening pattern 12 is provided in the cured film 3, and a diagram showing wiring 4 formed in the opening pattern 12 is shown. A bottom portion 13 of the wiring 4 extends into the cured film 3 up to the position where the wiring 4 contacts the electrode 6 of the light-emitting element 2, and shows the shape of the wiring 4 at the point of contact.

[0054] In the bottom view (b) of the surface of the designated area A in Figure 2 , excluding the light-emitting element, viewed from the opposing substrate side, the bottom surface 13 of the wiring 4 extending into the cured film 3 with the light-emitting element 2 removed is viewed from below, showing the bottom surface 13. The shape of the bottom surface 13 may vary depending on the product and the shape of the light-emitting element. In the case of a circular shape, the diameter is defined as the longest length 14, in the case of an elliptical shape, the major axis is defined as the longest length 14, and in the case of a polygon such as a rectangle, the longest diagonal line connecting the vertices of the corners is defined as the longest length 14. Note that the bottom surface 13 in the bottom view (b) of the surface of the designated area A in Figure 2 , excluding the light-emitting element, viewed from the opposing substrate side, shows an example of a circular shape.

[0055] This configuration allows for the application of minute light-emitting elements and enables high-density packaging of multiple light-emitting elements, resulting in a display device having high-resolution light-emitting elements in a wide range of sizes. Furthermore, it is possible to form fine wiring, which increases the number of wirings that can be formed per unit area, thereby reducing the overall thickness of the cured film. This prevents light emitted in all directions from the light-emitting element 2 from being absorbed in the cured film 3, thereby increasing light extraction efficiency and improving brightness. Furthermore, it is possible to reduce the height of the display device having the light-emitting element itself, and to reduce wiring defects such as wiring shorts due to shorter wiring distances, reduce loss, and improve high-speed response.

[0056] In the present invention, it is preferable that the maximum length of the bottom surface of the wiring formed in proximity to the light-emitting element is 2 μm or more and 20 μm or less. By adopting this configuration, minute light-emitting elements can be applied, and high-density packaging of multiple light-emitting elements becomes possible, resulting in a display device having light-emitting elements with high resolution in a wide range of sizes. Furthermore, it becomes possible to form finer wiring, and the number of wirings that can be formed per unit area increases, allowing the overall thickness of the cured film to be reduced, preventing light emitted in all directions from the light-emitting element 2 from being absorbed in the cured film 3, increasing light extraction efficiency, and improving brightness. Furthermore, it becomes possible to reduce the height of the display device having the light-emitting element itself, suppress wiring defects such as wiring shorts due to shorter wiring distances, suppress loss, and improve high-speed response.

[0057] From the viewpoint of applying minute light-emitting elements and achieving high-density mounting of light-emitting elements, the maximum length of the bottom surface of the wiring is preferably 2 μm or more and 15 μm or less, more preferably 2 μm or more and 10 μm or less, and even more preferably 2 μm or more and 5 μm or less. If it is less than 2 μm, poor connection with the light-emitting element 2 may occur, and if it exceeds 20 μm, it may hinder the application of minute light-emitting elements and high-density mounting.

[0058] The thickness of the cured film is preferably 1.1 times or more and 4.0 times or less the thickness of the wiring.

[0059] The thickness of the wiring, as explained in the enlarged cross-sectional view (a) of the designated area A in FIG. 2 , refers to the thickness a of the wiring 4 arranged on the surface of the cured film 3, and does not include the thickness of the wiring 4b extending into the opening pattern penetrating the cured film 3 in the thickness direction. The thickness of the wiring is preferably 0.1 μm or more and 10 μm or less, and more preferably 3 μm or more and 10 μm or less. By making the thickness of the wiring 0.1 μm or more and 10 μm or less, it is possible to reduce the height of the display device having the light-emitting element itself, suppress wiring defects such as wiring shorts due to shortened wiring distances, suppress low loss, and improve high-speed response. Furthermore, by making the thickness 3 μm or more and 10 μm or less, wiring resistance can be reduced, which can contribute to suppressing power consumption and improving brightness.

[0060] The thickness of the cured film refers to the thickness of the cured film 3a covering the wiring 4a, as explained with reference to the enlarged cross-sectional view (a) of the designated area A in FIG.

[0061] This allows for the production of a highly reliable cured film that also functions as a protective film for appropriate wiring and prevents wiring defects such as short circuits.

[0062] The thickness of the wiring may be the same or different in each layer. When the thicknesses are different, as an example, in FIG. 1, it is preferable that the thickness of the wiring closer to the bumps 10 is thicker than the thickness of the wiring closer to the light-emitting element 2. This makes it possible to suppress wiring defects when connecting the light-emitting element driving substrate 7 using the bumps 10, and to obtain a highly reliable display device.

[0063] In the present invention, it is preferable that the cured film covers a surface of the light-emitting element other than the light extraction surface. Note that the light extraction surface is considered to be the light extraction surface even when only a portion of the surface of the light-emitting element is covered with the cured film, as long as there is an area from which light can be extracted.

[0064] As an example, Figure 3 shows (a) a cross-sectional view of the light-emitting element driving substrate side of the designated area B in Figure 1 cut along a plane parallel to the opposing substrate, (b) a cross-sectional view at a position that does not include wiring perpendicular to the opposing substrate of the designated area B, and (c) a bottom view of the surface of the designated area B excluding the opposing substrate, as seen from the opposing substrate side.

[0065] In the cross-sectional view (a) of the light-emitting element driving substrate side of the designated region B in Figure 3 cut along a plane parallel to the opposing substrate, the light-emitting element 2 is covered with the cured film 3, and the wiring 4 that is connected to the electrode 6 of the light-emitting element and extends through the cured film 3 is shown from above. The cross-sectional shape of the wiring 4 may be circular or polygonal. In this case, the surface on which the electrode 6 is disposed serves as the light extraction surface.

[0066] In the cross-sectional view (b) of FIG. 3 at a position not including the wiring perpendicular to the opposing substrate, it is shown that the periphery of the light emitting element 2 is covered with the hardened film 3.

[0067] In the bottom view (c) of the surface of the designated region B in Figure 3 excluding the counter substrate, as viewed from the counter substrate side, the light-emitting element 2 is covered with the cured film 3, and the other electrode 6 of the light-emitting element is shown from the bottom. The cross-sectional shape of the electrode 6 may be circular or polygonal. The light-emitting element 2 may be covered with the cured film 3 except for the electrode 6.

[0068] 1 and 3, by covering the entire side surface and the top surface of the light-emitting element 2 with the cured film 3, the light-emitting element 2 can be protected from external impact. This is also preferable because it can flatten any steps that arise due to the arrangement of the light-emitting element 2 and also makes it easier to attach the light-emitting element 2 to the opposing substrate 5.

[0069] The cured film 3 covering the surfaces of the light-emitting element 2 other than the light extraction surface has the above-mentioned transmittance of light with a wavelength of 450 nm at a thickness of 5 μm, thereby suppressing absorption of light emitted from the light-emitting element 2 in the direction of the cured film 3, increasing light extraction efficiency, and improving brightness. From the viewpoint of improving brightness, it is more preferable that the transmittance of light with a wavelength of 450 nm at a thickness of 5 μm of the cured film 3 is 90% or more and 100% or less.

[0070] A display device according to a second aspect of the present invention is a display device having at least a substrate having wiring and / or TFTs, a cured film, and a plurality of light-emitting elements, wherein the light-emitting elements each have electrodes on two different surfaces, at least a portion of the wiring and / or TFTs is in contact with the cured film, the cured film is a film obtained by curing a resin composition containing (A) resin, and the transmittance of the cured film at a thickness of 5 μm for light with a wavelength of 450 nm is 80% or more and 100% or less.

[0071] The display device according to the second aspect of the present invention will be described with reference to FIG.

[0072] 30 , in the display device 1, a cured film 3 is arranged so that at least a portion of the substrate having wiring and / or TFTs is in contact with the cured film 3. The substrate having wiring and / or TFTs is, for example, a light-emitting element driving substrate 7, and an example is a TFT array substrate having wiring 4. Next, wiring 4e is arranged on at least a portion of the surface of the cured film 3 and on part of the opening pattern of the cured film 3, and then light-emitting elements 2 each having electrodes on two different surfaces are arranged on the wiring 4e.

[0073] In the embodiment shown in Figure 30, a polyhedral three-dimensional light-emitting element has one electrode on the surface connected to the wiring 4e and the other electrode on the surface facing the opposing substrate. Also shown is a configuration in which a cured film 3 is provided between or around the light-emitting elements 2. The electrode 6 not connected to the wiring 4e of a pair of electrodes 6 is connected to the wiring 4d. The wiring 4d may be formed on the opposing substrate 5. The electrode 6 and the wiring 4d may be connected via a bump, a conductive film, or the like, or may be connected directly. The wiring 4d may be connected to the wiring 4 extending through the cured film 3 arranged so as to contact at least a portion of the light-emitting element 2 via a through-electrode, or may be connected to the wiring 4e by wiring arranged on the side of the light-emitting element 2 or the side of the cured film 3 described below, or may be connected to the light-emitting element drive substrate 7. Furthermore, the light-emitting element 2 is electrically connected to the drive element 8 attached to the light-emitting element drive substrate 7 arranged opposite the opposing substrate 5 via the wiring 4 or 4c, thereby controlling the light emission of the light-emitting element 2. The light-emitting element drive substrate 7 is also electrically connected to the wiring 4 via, for example, a bump 10. Furthermore, a barrier metal 9 may be provided to prevent diffusion of metal such as the wiring 4. Note that the wiring 4c in the following drawings may be formed on the side surface of the light-emitting element drive substrate 7, may pass through the light-emitting element drive substrate 7, or may be connected to the drive element 8 as a wiring constituting the light-emitting element drive substrate.

[0074] As other examples of the display device according to the second aspect of the present invention, for example, configurations such as those shown in FIGS. 31 to 33 are preferable.

[0075] In the display device according to the second aspect of the present invention, the total thickness of the cured film is preferably 1 μm or more and 20 μm or less. By making the total thickness of the cured film 1 μm or more and 20 μm or less, it is possible to suppress absorption of light emitted in all directions from the light-emitting element 2 in the cured film 3, thereby increasing the light extraction efficiency and improving the brightness. Furthermore, it is possible to reduce the height of the display device having the light-emitting element itself, suppress wiring defects such as short circuits due to shorter wiring distances, suppress loss, and improve high-speed response.

[0076] In the second aspect of the present invention, the total thickness of the cured film refers to the total thickness of a continuous cured film layer in which at least a portion of one cured film is in contact with another cured film. For example, the range shown by 19 in Figure 30 above is the total thickness of the cured film layer. The total thickness is preferably 1 μm or more and 10 μm or less, more preferably 1 μm or more and 5 μm or less. If the thickness is less than 1 μm, the wiring is not sufficiently protected, which may lead to wiring defects such as short circuits. If the thickness exceeds 10 μm, it becomes difficult to form fine wiring, which may lead to problems such as wiring defects such as short circuits.

[0077] In the present invention, it is preferable to provide a reflective film on the cured film.

[0078] As shown in Fig. 4, a reflective film 15 is provided on the cured film 3 disposed around the light-emitting element 2. By providing the reflective film 15 on the cured film 3 having high light transmittance as described above, the light passing through the cured film 3 is reflected by the reflective film 15, thereby further increasing the extraction efficiency and improving the brightness.

[0079] The reflective film can be provided at any position on the cured film, and can be disposed so as to surround all four sides in the extraction direction of the light-emitting element, disposed at an angle to the light-emitting element, or disposed with a curve. The reflective film can be any film that reflects light, and examples of the reflective film include, but are not limited to, aluminum, silver, copper, titanium, and alloys containing these.

[0080] In the present invention, it is preferable that a partition wall having a thickness equal to or greater than the thickness of the light emitting element is provided between the plurality of light emitting elements.

[0081] 5, it is preferable to have partition walls 16 in a repeating pattern corresponding to the number of pixels of the display device 1 having the light-emitting elements 2, i.e., between or around each light-emitting element 2. The electrode 6 and the wiring 4 or 4d may be connected via a bump or the like, or may be connected directly. This configuration is preferable because it facilitates bonding to the opposing substrate 5 which may include the wiring 4d.

[0082] The thickness of the partition wall is preferably larger than the thickness of each light emitting element, and specifically, is preferably 5 μm or more and 120 μm or less.

[0083] The partition walls may be formed from a cured film obtained by curing a resin composition containing the (A) resin, or may be formed from a material other than the resin composition containing the (A) resin, such as a known material such as an epoxy resin, a (meth)acrylic polymer, a polyurethane, a polyester, a polyolefin, or a polysiloxane. By using these materials, partition walls with excellent adhesion can be formed.

[0084] In order to suppress light leakage from the light-emitting elements and color mixing between pixels and improve contrast, a light-shielding portion may be provided on the side surface of the partition wall or on the partition wall itself. The light-shielding portion is, for example, a portion containing a black pigment. Furthermore, a reflective portion may be provided on the side surface of the partition wall to reflect light emitted from the light-emitting elements toward the partition wall and thereby improve light extraction efficiency and brightness. The reflective portion is, for example, a portion containing a white pigment.

[0085] It is preferable that a partition wall having a thickness equal to or greater than the thickness of the light emitting element is disposed between the plurality of light emitting elements in the cured film covering the light emitting elements.

[0086] As another embodiment in which partition walls are provided, as shown in FIG. 6, a configuration in which partition walls 16 are provided between or around the light emitting elements 2 in the cured film 3 covering the light emitting elements 2 is exemplified.

[0087] 6 may be made of a material other than the resin composition containing the resin (A), and may be made of known materials such as epoxy resin, (meth)acrylic polymer, polyurethane, polyester, polyolefin, polysiloxane, etc. By using these materials, partition walls with excellent adhesion can be formed.

[0088] The partition walls are preferable because they can serve as markers for subsequent transfer of light-emitting elements and can also be used as photospacers, thereby improving the efficiency of light-emitting element transfer. Furthermore, in order to suppress light leakage from the light-emitting elements and color mixing between pixels and improve contrast, light-shielding portions may be provided on the side surfaces of the partition walls or on the partition walls themselves. The light-shielding portions are, for example, portions containing black pigments.

[0089] In the present invention, it is also preferable to provide a configuration in which partition walls having a thickness equal to or greater than the thickness of the light emitting elements are disposed between the plurality of light emitting elements, and a reflective film is provided around the partition walls.

[0090] Specifically, as shown in Figures 7 and 8, a display device configuration can be mentioned in which a partition 16 having a thickness greater than or equal to the thickness of the light-emitting element 2 is arranged between multiple light-emitting elements 2, and a reflective film 15 is provided around the partition.

[0091] By providing a reflective film around the partition wall, light emitted from the light emitting element is reflected by the reflective film around the partition wall, thereby increasing the light extraction efficiency and improving the brightness.

[0092] In order to suppress light leakage from the light-emitting elements and color mixing between pixels and improve contrast, a light-shielding portion may be provided on the side surface of the partition wall or on the partition wall itself. The light-shielding portion is, for example, a portion containing a black pigment. Furthermore, a reflective portion may be provided on the side surface of the partition wall to reflect light emitted from the light-emitting elements toward the partition wall and thereby improve light extraction efficiency and brightness. The reflective portion is, for example, a portion containing a white pigment.

[0093] In the present invention, a light diffusing layer may be provided around the light emitting element, the cured film, or the wiring.

[0094] In the present invention, the light emitting element is preferably an LED having a side length of 5 μm or more and 700 μm or less, and more preferably an LED having a side length of 5 μm or more and 100 μm or less.

[0095] An LED is composed of a PN junction, where a P-type semiconductor and an N-type semiconductor are joined. When a forward voltage is applied to an LED, electrons and holes move within the chip, causing a current to flow. The electrons and holes combine to create an energy difference, which converts the excess energy into light energy and emits light. The wavelength of light emitted from an LED varies depending on the compound that makes up the semiconductor, such as GaN, GaAs, InGaAlP, or GaP, and this difference in wavelength determines the emitted color. While white is typically displayed by mixing two or more different colors of light, LEDs can significantly improve color reproducibility by mixing the three primary colors of red, green, and blue, making it possible to display a more natural white color.

[0096] The LED may be of a bullet type, chip type, polygonal type, etc., but the chip type or polygonal type is preferred from the viewpoint of miniaturization of the LED. Furthermore, it is preferable that the length of one side of the LED is 5 μm or more and 700 μm or less, since this allows for the arrangement of multiple chips, and it is even more preferable that the length of one side of the LED is 5 μm or more and 100 μm or less.

[0097] The light-emitting element has electrodes on two different surfaces. The term "two different surfaces" refers to a light-emitting element having two or more surfaces, where one of the surfaces having an electrode is taken as a reference surface, and the other electrodes are provided on a surface different from the reference surface.

[0098] In the present invention, it is preferable that an electrode be provided on each of the opposing surfaces sandwiching the light-emitting element. It is also preferable that an electrode be provided on each of the adjacent surfaces of the light-emitting element. Examples of providing electrodes on two different surfaces of the light-emitting element include structures such as those shown in FIGS. 1 and 25 in which electrodes 6 are arranged on opposing surfaces sandwiching the light-emitting element 2, and examples of providing electrodes on each of the adjacent surfaces of the light-emitting element include a structure such as that shown in FIG. 26. By providing electrodes on each of the opposing surfaces sandwiching the light-emitting element, or by providing electrodes on each of the adjacent surfaces of the light-emitting element, it is possible to reduce the size of the light-emitting element, thereby enabling a display device with high resolution to be obtained through low cost and high-density packaging.

[0099] In the present invention, it is also preferable to provide an electrode on each discontinuous surface. A discontinuous surface is not a continuous surface, but a surface having steps, for example, structures such as those shown in Figures 27 to 29. By providing electrodes 6 on the discontinuous surfaces, it is possible to control the light-emitting area in the light-emitting element and improve the productivity and light-emitting efficiency of the light-emitting element.

[0100] As a method for mounting the light-emitting element on a substrate such as the light-emitting element driving substrate 7 on which the cured film 3 of the light-emitting element is arranged, for example, a pick-and-place method or a mass transfer method has been proposed, but the method is not limited to these.

[0101] Examples of methods for mounting light-emitting elements on a substrate include a method in which light-emitting elements emitting red, green, and blue are arranged in a matrix at predetermined positions on the substrate, and a method in which a single type of light-emitting element, such as a light-emitting element emitting red or blue or an ultraviolet light-emitting element emitting ultraviolet light, is arranged on the substrate. The former method may use light-emitting elements emitting red, green, and blue, respectively, or may use a vertical stack of light-emitting elements emitting red, green, and blue. The latter method facilitates the array mounting of light-emitting elements. In this case, wavelength conversion materials such as quantum dots can be used to create red, green, and blue subpixels to achieve a full-color display. Furthermore, two or more light-emitting elements may be packaged and then mounted on a substrate.

[0102] Known wavelength converting materials can be used.

[0103] For example, when using light-emitting elements that emit blue light, it is preferable to first fabricate a light-emitting element array substrate on which only light-emitting elements that emit blue light are arranged and mounted, and then arrange wavelength conversion layers that are excited by blue light and emit red or green light at positions corresponding to the red and green subpixels. This makes it possible to form red, green, and blue subpixels using only light-emitting elements that emit blue light.

[0104] On the other hand, when ultraviolet light-emitting elements that emit ultraviolet light are used, it is preferable to first fabricate a light-emitting element array substrate on which only ultraviolet light-emitting elements are arranged and mounted, and then arrange wavelength conversion layers that are excited by ultraviolet light and emit red, green, and blue light at positions corresponding to the red, green, and blue subpixels, thereby suppressing the difference in light emission angle depending on the color of the subpixels.

[0105] As the wavelength conversion layer, a known material can be used, and a color filter or the like may also be used as needed.

[0106] The counter substrate in the present invention is not particularly limited, and known substrates can be used. Examples include a glass plate, a resin plate, a resin film, a sapphire substrate, a printed wiring board, a TFT array substrate, and ceramics. The glass plate is preferably made of alkali-free glass. The resin plate and resin film are preferably made of polyester, (meth)acrylic polymer, transparent polyimide, polyethersulfone, and the like. The thickness of the glass plate and resin plate is preferably 1 mm or less, and more preferably 0.8 mm or less. The resin film is preferably made of 100 μm or less.

[0107] In the present invention, the display device preferably includes a driving element, and the light-emitting elements are electrically connected to the driving element through wiring extending in the cured film. The display device includes a driving element, and the light-emitting elements are electrically connected to the driving element through wiring extending in the cured film, so that one or more light-emitting elements can be individually switched. Examples of the driving element include a driver IC, and one or more driver ICs may be used for a package containing one or more light-emitting elements or multiple light-emitting elements consisting of red, blue, green, etc., according to function.

[0108] As a configuration for arranging the driving elements, a configuration in which the driving elements 8 are arranged in the cured film 3 on the opposing substrate 5 near the light-emitting element 2 is preferred, as shown in Fig. 9. Also preferred is a configuration in which the driving elements 8 are arranged in the cured film at a position above the light-emitting element 2, as shown in Fig. 10. This makes it possible to suppress wiring defects such as short circuits due to shorter wiring distances, suppress loss, and improve high-speed response.

[0109] In the present invention, it is preferable that the display device further includes a driving element and a substrate, the driving element being connected to the light-emitting elements through wiring, and at least a portion of the wiring extending to a side surface of the substrate. By including a driving element and a substrate, the driving element being connected to the light-emitting elements through wiring, and at least a portion of the wiring extending to a side surface of the substrate, it is possible to individually switch-drive a plurality of light-emitting elements, reduce the height and improve the high-speed response of the display device itself, and further reduce the size and narrow the frame of the display device.

[0110] The substrate is not particularly limited, as with the light-emitting element drive substrate 7, and known substrates can be used. Examples include glass substrates, sapphire substrates, TFT array substrates, ceramics, etc. The wiring that extends at least partially to the side surface of the substrate is preferably arranged as shown in 4c in Figures 1, 5, and 18 to 20.

[0111] In the present invention, it is preferable to further provide a light-shielding layer between the plurality of light-emitting elements. By providing a light-shielding layer between the plurality of light-emitting elements, it is possible to suppress light leakage from the light-emitting elements and color mixing between pixels, and improve contrast, without significantly impairing the light extraction efficiency.

[0112] The light-shielding layer may be composed of a cured film obtained by curing a resin composition containing (A) resin and (E) colorant, or may be composed of a material other than the resin composition containing (A), such as an epoxy resin, (meth)acrylic polymer, polyurethane, polyester, polyolefin, or polysiloxane. The (E) colorant may be a black pigment, such as black organic pigments such as carbon black, perylene black, or aniline black; graphite; or inorganic pigments such as metal fine particles of titanium, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, or silver; metal oxides, composite oxides, metal sulfides, metal nitrides, or metal oxynitrides. A black color may also be achieved by combining a red pigment and a blue pigment, or, if necessary, a yellow pigment or other pigment. A dye may also be used. Two or more colorants may be used.

[0113] The resin composition containing the (A) resin and the (E) colorant may be made photosensitive, and a (B) photosensitizer described below may be used.

[0114] A preferred method for producing a resin composition containing the (A) resin and the (E) colorant is, for example, to use a disperser to disperse a resin solution containing the (A) resin, the (E) colorant, and optionally a dispersant and an organic solvent, to prepare a colorant dispersion with a high colorant concentration, and then to add the (A) resin and, optionally, other components such as a photosensitizer, followed by stirring. Filtration may be performed as necessary.

[0115] Examples of dispersing machines include ball mills, bead mills, sand grinders, three-roll mills, and high-speed impact mills. Among these, bead mills are preferred for improving dispersion efficiency and achieving fine dispersion. Examples of bead mills include co-ball mills, basket mills, pin mills, and dyno mills. Examples of beads used in bead mills include titania beads, zirconia beads, and zircon beads. The bead diameter of the bead mill is preferably 0.03 mm or more and 1.0 mm or less. (E) When the primary particle diameter of the colorant and the particle diameter of the secondary particles formed by aggregation of the primary particles are small, it is preferable to use fine beads with a diameter of 0.03 mm or more and 0.10 mm or less. In this case, a bead mill equipped with a centrifugal separator capable of separating the fine beads from the dispersion is preferred. On the other hand, when dispersing a colorant containing coarse particles on the submicron scale, it is preferable to use beads with a diameter of 0.10 mm or more to obtain sufficient crushing power.

[0116] The resin composition containing the resin (A) and the colorant (E) can be applied to various substrates, dried, and then heat-treated to obtain a light-shielding layer. If the resin composition has photosensitivity, it can be exposed to actinic rays described below, and then developed and heat-treated to obtain a patterned light-shielding layer.

[0117] The thickness of the light-shielding layer is preferably 0.1 μm or more and 5 μm or less. When the thickness of the light-shielding layer is 0.1 μm or more, light leakage from the light-emitting element and color mixing between pixels can be suppressed, and contrast can be improved. The thickness of the light-shielding layer is more preferably 0.5 μm or more. On the other hand, when the thickness of the wiring is 5 μm or less, light leakage from the light-emitting element and color mixing between pixels can be suppressed and contrast can be improved without significantly impairing the light extraction efficiency. The thickness of the light-shielding layer is more preferably 4 μm or less.

[0118] The light-shielding layer is a colored film formed on a 0.7 mm thick alkali-free glass substrate to a thickness of 1.0 μm. The reflective chromaticity values ​​(a*, b*) measured from the glass surface preferably fall within the ranges of -0.5≦a*≦1.0 and -1.0≦b*≦0.5, and more preferably fall within the ranges of -0.5≦a*≦0.5 and -1.0≦b*≦0.4. Reflected chromaticity is an index of the color tone of an image reflected in the colored film, and the closer the reflection chromaticity is to (a*, b*) = (0.0, 0.0), the more achromatic the reflection tone. On the other hand, the reflection tone of black display in liquid crystal display devices and organic EL displays generally has a negative b* value, resulting in a bluish hue. Therefore, a negative b* value is preferred for decorative films used in display devices.

[0119] The reflection chromaticity (L*, a*, b*) of the colored film can be obtained by measuring the total reflection chromaticity (SCI) of light incident from a transparent substrate under the measurement conditions of standard illuminant D65 (color temperature 6504K), a viewing angle of 2° (CIE1976), atmospheric pressure, and 20°C using a spectrophotometer (CM-2600d; manufactured by Konica Minolta, Inc.) calibrated with a white calibration plate (CM-A145; manufactured by Konica Minolta, Inc.).

[0120] A preferred configuration of the light-shielding layer is, for example, the configuration shown by 26 in Fig. 21. The light-shielding layer 26 may be in contact with the light-emitting element 2 or may be separated from it.

[0121] In the present invention, a cured film obtained by curing a resin composition containing the (A) resin has a light transmittance of 80% or more and 100% or less at a wavelength of 450 nm at a thickness of 5 μm, which prevents light emitted in all directions from the light-emitting element from being absorbed in the cured film obtained by curing the resin composition containing the (A) resin, thereby increasing the light extraction efficiency and improving the brightness.

[0122] To obtain such properties, the (A) resin preferably has high heat resistance, specifically, one that is less susceptible to resin degradation at high temperatures of 160° C. or higher during or after heat treatment and that is less susceptible to the formation of, for example, a quinone structure, which is one of the colored structures, associated with resin degradation, decomposition, etc. Furthermore, such a cured film is preferred because it reduces the amount of outgassing, which is one of the excellent properties of cured films used in display devices, such as insulating films, protective films, and partition walls.

[0123] Furthermore, from the viewpoint of forming a desired opening pattern by exposure and development, the resin (A) preferably has high transmittance to light at the exposure wavelength before curing.

[0124] In order to obtain such properties, it is preferable to shorten the conjugated chain derived from the aromatic ring of the resin, or to reduce the charge transfer within or between molecules.

[0125] Furthermore, for the purpose of protecting the wiring, it is preferable that the processability is excellent even for a thick film having a thickness of 10 μm or more.

[0126] The resin (A) is not particularly limited, but is preferably an alkali-soluble resin from the viewpoint of reducing environmental impact. Alkali-soluble resins are defined as follows: a solution of the resin dissolved in γ-butyrolactone is applied to a silicon wafer and prebaked at 120°C for 4 minutes to form a prebaked film with a film thickness of 10 μm±0.5 μm. Here, prebaking refers to a process of heating and drying the applied film, and the prebaked film refers to the film obtained after the heating and drying. The term "prebaked film" is also synonymous with "resin film." The prebaked film is then immersed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23±1°C for 1 minute, and the film thickness reduction is determined after rinsing with pure water. A prebaked film with a dissolution rate of 50 nm / min or higher is defined as alkali-soluble.

[0127] The resin (A) preferably contains one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof. The resin (A) may contain these resins alone or in combination.

[0128] The following describes polyimides, polyimide precursors, polybenzoxazoles, and polybenzoxazole precursors. The polyimides are not particularly limited as long as they have an imide ring. The polyimide precursors are not particularly limited as long as they have a structure that becomes a polyimide having an imide ring upon dehydration and ring closure, and may contain polyamic acid, polyamic acid ester, or the like. The polybenzoxazoles are not particularly limited as long as they have an oxazole ring. The polybenzoxazole precursors are not particularly limited as long as they have a structure that becomes a polybenzoxazole having a benzoxazole ring upon dehydration and ring closure, and may contain polyhydroxyamide, or the like.

[0129] The polyimide has a structural unit represented by general formula (1), the polyimide precursor and the polybenzoxazole precursor have a structural unit represented by the following general formula (2), and the polybenzoxazole has a structural unit represented by general formula (3). Two or more of these may be contained, or a resin may be contained in which the structural unit represented by general formula (1), the structural unit represented by general formula (2), and the structural unit represented by general formula (3) are copolymerized.

[0130]

[0131] In general formula (1), V represents a tetravalent to decavalent organic group having 4 to 40 carbon atoms, W represents a divalent to octavalent organic group having 4 to 40 carbon atoms, and a and b each represent an integer of 0 to 6. １ and R ２ represents a group selected from the group consisting of a hydroxyl group, a carboxyl group, a sulfonic acid group, and a thiol group, and a plurality of R １ and R ２ may be the same or different.

[0132]

[0133] In the general formula (2), X and Y each independently represent a divalent to octavalent organic group having 4 to 40 carbon atoms. ３ and R ４each independently represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, c and d each represent an integer of 0 to 4, and e and f each represent an integer of 0 to 2.

[0134]

[0135] In the general formula (3), T and U each independently represent a divalent to octavalent organic group having 4 to 40 carbon atoms.

[0136] In order to impart alkali solubility to the (A) resin, it is preferable that a + b > 0 in general formula (1). Also, it is preferable that c + d + e + f > 0 in general formula (2). In the case of a polyimide precursor, it is preferable that X and Y in general formula (2) have aromatic groups. Furthermore, X in general formula (2) has an aromatic group, e > 2, and has a carboxy group or a carboxy ester group at the ortho position of the aromatic amide group, resulting in a structure in which an imide ring is formed by dehydration ring closure.

[0137] In the case of a polybenzoxazole precursor, X in general formula (2) has an aromatic group, d>0, and has a hydroxyl group at the ortho-position of the aromatic amide group, and forms a structure that forms a benzoxazole ring by dehydration ring closure.

[0138] In the resin (A), the repeating number n of the structural unit represented by general formula (1), general formula (2), or general formula (3) is preferably 5 to 100,000, and more preferably 10 to 100,000.

[0139] In addition, the (A) resin may have other structural units in addition to the structural units represented by general formula (1), general formula (2), or general formula (3). Examples of other structural units include, but are not limited to, cardo structures and siloxane structures. In this case, it is preferable that the structural units represented by general formula (1) or general formula (2) are the main structural units. Here, the main structural units refer to structural units represented by general formula (1), general formula (2), or general formula (3) that account for 50 mol% or more of the total number of structural units, and more preferably 70 mol% or more.

[0140] In the above general formula (1), V-(R １ ) ａ In the above general formula (2), (OH) ｃ -X-(COOR ３ ) ｅ In the general formula (3), T represents an acid residue. V represents a tetravalent to decavalent organic group having 4 to 40 carbon atoms, and is preferably an organic group having 4 to 40 carbon atoms and containing an aromatic ring or a cyclic aliphatic group. X and T represent divalent to octavalent organic groups having 4 to 40 carbon atoms, and is preferably an organic group having 4 to 40 carbon atoms and containing an aromatic ring or an aliphatic group.

[0141] Examples of acid components constituting the acid residue include dicarboxylic acids such as terephthalic acid, isophthalic acid, diphenyl ether dicarboxylic acid, bis(carboxyphenyl)hexafluoropropane, biphenyl dicarboxylic acid, benzophenone dicarboxylic acid, triphenyl dicarboxylic acid, suberic acid, dodecafluorosuberic acid, azelaic acid, sebacic acid, hexadecafluorosebacic acid, 1,9-nonanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecane dicarboxylic acid. Examples of tricarboxylic acids include trimellitic acid, trimesic acid, diphenyl ether tricarboxylic acid, and biphenyl tricarboxylic acid. Examples of tetracarboxylic acids include pyromellitic acid, 3,3',4,4'-biphenyl tetracarboxylic acid, and 2,3,3',4'-biphenyl tetracarboxylic acid. tetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid, 3,3',4,4'-diphenylethertetracarboxylic acid, 3,3',4,4'-benzophenonetetracarboxylic acid, 2,2',3,3'-benzophenonetetracarboxylic acid, 2,2-bis(3,4-dicarboxyphenyl)propane, 2,2-bis(2,3-dicarboxyphenyl)propane, 1,1-bis(3,4-dicarboxyphenyl)ethane, 1,1-bis(2,3-dicarboxyphenyl)ethane, bis(3,4-dicarboxyphenyl) phenyl)methane, bis(2,3-dicarboxyphenyl)methane, bis(3,4-dicarboxyphenyl)ether, 1,2,5,6-naphthalenetetracarboxylic acid, 9,9-bis(3,4-dicarboxyphenyl)fluorene, 9,9-bis{4-(3,4-dicarboxyphenoxy)phenyl}fluorene, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,3,5,6-pyridinetetracarboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, 2,2-bis(3,Examples of suitable tetracarboxylic acids include, but are not limited to, 4-dicarboxyphenyl)hexafluoropropane, aromatic tetracarboxylic acids having the structures shown below, butane tetracarboxylic acid, cyclobutane tetracarboxylic acid, and 1,2,3,4-cyclopentane tetracarboxylic acid. Two or more of these may be used.

[0142]

[0143] In the formula, R １７ is an oxygen atom, C(CF ３ ) ２ , or C(CH ３ ) ２ Represents R １８ and R １９ represents a hydrogen atom or a hydroxyl group.

[0144] These acids can be used as they are, or as acid anhydrides, halides, or activated esters.

[0145] W-(R ２ ) ｂ , (OH) in the above general formula (2) ｄ -Y-(COOR ４ ) ｆ In the general formula (3), U represents a residue of a diamine. W, Y, and U are divalent to octavalent organic groups having 4 to 40 carbon atoms, and among these, organic groups having 4 to 40 carbon atoms and containing an aromatic ring or a cycloaliphatic group are preferred.

[0146] Specific examples of diamines constituting the diamine residue include hydroxyl group-containing diamines such as bis(3-amino-4-hydroxyphenyl)hexafluoropropane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(3-amino-4-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)methylene, bis(3-amino-4-hydroxyphenyl)ether, bis(3-amino-4-hydroxy)biphenyl, and bis(3-amino-4-hydroxyphenyl)fluorene; 3-sulfonic acid-4,4'-diamine; sulfonic acid-containing diamines such as dimercaptophenylenediamine, thiol group-containing diamines such as dimercaptophenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 1,4-bis(4-aminophenoxy)benzene, benzine, m-phenylenediamine , p-phenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, bis(4-aminophenoxyphenyl)sulfone, bis(3-aminophenoxyphenyl)sulfone, bis(4-aminophenoxy)biphenyl, bis{4-(4-aminophenoxy)phenyl}ether, 1,4-bis(4-aminophenoxy)benzene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4' aromatic diamines such as 2,2'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, 3,3',4,4'-tetramethyl-4,4'-diaminobiphenyl, and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, and compounds in which some of the hydrogen atoms in the aromatic rings of these are substituted with alkyl groups or fluoroalkyl groups having 1 to 10 carbon atoms, halogen atoms, or the like; 2,4-diamino-1,3,5-triazine (guanamine), 2,4-diamino-6-methyl-1,3,5-triazine (acetoguanamine), 2,Examples of such diamines include diamines having a nitrogen-containing heteroaromatic ring, such as 4-diamino-6-phenyl-1,3,5-triazine (benzoguanamine); silicone diamines, such as 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(p-aminophenyl)-1,1,3,3-tetramethyldisiloxane, 1,3-bis(p-aminophenethyl)-1,1,3,3-tetramethyldisiloxane, and 1,7-bis(p-aminophenyl)-1,1,3,3,5,5,7,7-octamethyltetrasiloxane; alicyclic diamines, such as cyclohexyldiamine and methylenebiscyclohexylamine; and diamines having the structures shown below. Two or more of these may be used.

[0147]

[0148] In the formula, R ２０ is an oxygen atom, C(CF ３ ) ２ , or C(CH ３ ) ２ Represents R ２１ ~R ２４ each independently represents a hydrogen atom or a hydroxyl group.

[0149] Among these, from the viewpoint of improving the alkali developability and the transmittance of the (A) resin and its cured film at a standard thickness of 5 μm for light with a wavelength of 450 nm, it is preferable to contain at least one diamine having the structure shown below.

[0150]

[0151] In the formula, R ２０ is an oxygen atom, C(CF ３ ) ２ , or C(CH ３ ) ２ Represents R ２１ ~R ２２ each independently represents a hydrogen atom or a hydroxyl group.

[0152] These diamines can be used as they are, or as diisocyanate compounds or trimethylsilylated diamines obtained by reacting the diamines with phosgene.

[0153] Furthermore, the resin (A) preferably contains a group selected from an alkylene group and an alkylene ether group. These groups may contain an aliphatic ring. As the group selected from the alkylene group and the alkylene ether group, a group represented by general formula (4) is particularly preferred.

[0154]

[0155] In general formula (4), R ５ ~R ８ R each independently represents an alkylene group having 1 to 6 carbon atoms. ９ ~R １６ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 6 carbon atoms. However, the structures represented in the parentheses are different. g, h, and i each independently represent an integer of 0 to 35, and g + h + i > 0.

[0156] Examples of the group represented by formula (4) include an ethylene oxide group, a propylene oxide group, and a butylene oxide group, and the group may be linear, branched, or cyclic.

[0157] When the (A) resin contains a group selected from an alkylene group and an alkylene ether group, the mechanical properties, particularly the elongation, of the (A) resin and a cured film thereof can be improved, and the transmittance of light at 450 nm before and after curing can be further improved.

[0158] The (A) resin preferably contains a group selected from the alkylene group and the alkylene ether group as W in the general formula (1) or Y in the general formula (2), thereby improving the mechanical properties, particularly the elongation, of the (A) resin and a cured film thereof, and further improving the transmittance of light at 450 nm before and after curing, and also achieving high chemical resistance due to the promotion of ring closure by low-temperature heat treatment in a cured film of the resin composition, high adhesion to substrate metals, and resistance to a constant temperature and humidity test (HAST).

[0159] Specific examples of diamines containing a group selected from an alkylene group and an alkylene ether group include ethylenediamine, 1,3-diaminopropane, 2-methyl-1,3-propanediamine, 1,4-diaminobutane, 1,5-diaminopentane, 2-methyl-1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,2-cyclohexanediamine, 1,3-cyclohexanediamine, 1,4-cyclohexanediamine, 1,2-bis(aminomethyl)cyclohexane, 1,3 -bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), KH-511, ED-600, ED-900, ED-2003, EDR-148, EDR-176, D-200, D- 400, D-2000, THF-100, THF-140, THF-170, RE-600, RE-900, RE-2000, RP-405, RP-409, RP-2005, RP-2009, RT-1000, HE-1000, HT-1100, HT-1700 (all trade names, manufactured by HUNTSMAN Co., Ltd.).

[0160] In addition, these diamines may contain -S-, -SO-, -SO ２ -, -NH-, -NCH ３ -, -N(CH ２ CH ３ ) -, -N(CH ２ CH ２ CH ３ )-,-N(CH(CH ３ ) ２ )-, -COO-, -CONH-, -OCONH-, -NHCONH-, and the like.

[0161] The diamine residues containing a group selected from an alkylene group and an alkylene ether group are preferably contained in an amount of 5 mol% or more, more preferably 10 mol% or more, of all diamine residues. Furthermore, the amount of the diamine residues is preferably 40 mol% or less, more preferably 30 mol% or less, of all diamine residues. By ensuring the amount is within the above range, the developability in an alkaline developer is improved, the mechanical properties, particularly the elongation, of the (A) resin and its cured film are improved, and the transmittance of light at 450 nm after curing can be improved. Furthermore, the cured film of the resin composition can be provided with high chemical resistance due to the promotion of ring closure by low-temperature heat treatment, high adhesion to metal surfaces, and resistance to constant temperature and humidity test (HAST).

[0162] Diamine residues having an aliphatic polysiloxane structure may be copolymerized within a range that does not reduce heat resistance. Copolymerization of diamine residues having an aliphatic polysiloxane structure can improve adhesion to substrates. Specific examples of diamine components include those obtained by copolymerizing 1 to 15 mol % of all diamine residues with bis(3-aminopropyl)tetramethyldisiloxane, bis(p-aminophenyl)octamethylpentasiloxane, or the like. Copolymerization within this range is preferred in terms of improving adhesion to substrates such as silicon wafers and not reducing solubility in alkaline solutions.

[0163] A resin having an acidic group at the end of the main chain can be obtained by capping the terminals of the (A) resin with a monoamine, acid anhydride, acid chloride, or monocarboxylic acid having an acidic group. Known monoamines, acid anhydrides, acid chlorides, and monocarboxylic acids having an acidic group may be used, or multiple monoamines, acid anhydrides, acid chlorides, and monocarboxylic acids may be used.

[0164] The content of the end-capping agent such as the monoamine, acid anhydride, acid chloride, or monocarboxylic acid is preferably 2 to 25 mol % relative to 100 mol % of the total of the acid components and amine components constituting the resin (A).

[0165] The (A) resin preferably has a weight-average molecular weight of 10,000 or more and 100,000 or less. If the weight-average molecular weight is 10,000 or more, the mechanical properties of the cured film after curing can be improved. More preferably, the weight-average molecular weight is 20,000 or more. On the other hand, if the weight-average molecular weight is 100,000 or less, the developability with various developers can be improved, and if the weight-average molecular weight is 50,000 or less, the developability with an alkaline solution can be improved, which is preferable.

[0166] The weight average molecular weight (Mw) can be determined using gel permeation chromatography (GPC). For example, it can be measured using N-methyl-2-pyrrolidone (hereinafter sometimes abbreviated as NMP) as the developing solvent and calculated in terms of polystyrene.

[0167] The content of the (A) resin is preferably 3 to 55% by mass, and more preferably 5 to 40% by mass, of 100% by mass of all components including the solvent. By setting the content within this range, a viscosity appropriate for spin coating or slit coating can be achieved.

[0168] Other examples of resins that can be used include phenolic resins, polymers containing radically polymerizable monomers having alkali-soluble groups as monomer units, such as polyhydroxystyrene and acrylic, siloxane polymers, cyclic olefin polymers, and cardo resins. These resins may be used as known resins, and may be used alone or in combination.

[0169] In the present invention, the resin composition containing the resin (A) preferably contains a photosensitizer (B) (hereinafter, sometimes referred to as component (B)).

[0170] By including the photosensitizer (B), the resin composition is preferably made photosensitive, which allows the formation of a fine opening pattern.

[0171] (B) Photosensitizer is a compound whose chemical structure changes in response to ultraviolet light, and examples thereof include photoacid generators, photobase generators, photopolymerization initiators, etc. When a photoacid generator is used as (B) photosensitizer, acid is generated in the irradiated portions of the photosensitive resin composition, increasing the solubility of the irradiated portions in an alkaline developer, thereby making it possible to obtain a positive pattern in which the irradiated portions dissolve.

[0172] When (B) a photobase generator is contained as the photosensitizer, a base is generated in the irradiated parts of the resin composition, and the solubility of the irradiated parts in an alkaline developer decreases, so that a negative pattern can be obtained in which the irradiated parts are insolubilized.

[0173] When the resin composition contains a photopolymerization initiator (B) as a photosensitizer, radicals are generated in the irradiated area of ​​the resin composition, which causes radical polymerization and makes the resin insoluble in an alkaline developer, thereby forming a negative pattern. In addition, UV curing during exposure is promoted, thereby improving sensitivity.

[0174] In the present invention, a cured film obtained by curing a resin composition containing (A) resin and (B) photosensitizer has a light transmittance of 80% or more and 100% or less at a wavelength of 450 nm at a thickness of 5 μm, which prevents light emitted in all directions from the light-emitting element from being absorbed in the cured film obtained by curing the resin composition containing (A) resin and (B) photosensitizer, thereby increasing the light extraction efficiency and improving the brightness.

[0175] In order to obtain such properties, the (B) photosensitizer is preferably one that has high light transmittance at a wavelength of 450 nm and high heat resistance, and that has little formation of, for example, a quinone structure, which is one of the colored structures, or one that has high light transmittance for the reaction product of the (B) photosensitizer with the (A) resin or the (C) thermal crosslinking agent, or one that has high light transmittance for the decomposition product of the (B) photosensitizer itself or a reaction product derived from the decomposition product. Furthermore, it is preferable to perform an exposure treatment before curing the resin composition containing the (B) photosensitizer in order to reduce coloration during heat treatment.

[0176] The resin composition containing (A) resin and, if necessary, (B) photosensitizer preferably has positive photosensitivity from the viewpoint of fine processing ability.

[0177] Among the above-mentioned photosensitizers (B), photoacid generators are preferred from the viewpoint of high sensitivity and fine processability. Examples of photoacid generators include quinone diazide compounds, sulfonium salts, phosphonium salts, diazonium salts, and iodonium salts. Furthermore, a sensitizer or the like may be contained as needed.

[0178] The quinone diazide compound is preferably a compound having a phenolic hydroxyl group and a naphthoquinone diazide sulfonic acid bonded to the compound via an ester bond. The compound having a phenolic hydroxyl group used here may be a known compound, and examples of the compound having a phenolic hydroxyl group to which 4-naphthoquinone diazide sulfonic acid or 5-naphthoquinone diazide sulfonic acid is introduced via an ester bond can be given as preferred examples, but other compounds can also be used.

[0179] In addition, it is preferable that 50 mol % or more of all functional groups of the compound having a phenolic hydroxyl group are substituted with quinone diazide. By using a quinone diazide compound substituted by 50 mol % or more, the affinity of the quinone diazide compound for alkaline aqueous solutions is reduced. As a result, the solubility of the unexposed portions of the resin composition in alkaline aqueous solutions is significantly reduced. Furthermore, the quinone diazide sulfonyl groups are converted to indene carboxylic acid by exposure, resulting in a high dissolution rate of the exposed portions of the photosensitive resin composition in alkaline aqueous solutions. That is, as a result, the dissolution rate ratio between the exposed and unexposed portions of the composition is increased, allowing for the production of patterns with high resolution.

[0180] By containing such a quinone diazide compound, it is possible to obtain a resin composition having positive photosensitivity that is sensitive to the i-line (365 nm), h-line (405 nm), and g-line (436 nm) of a general mercury lamp, or to a broad band including these. In addition, the (B) photosensitizer may be contained alone or in combination of two or more types, and a highly sensitive resin composition can be obtained.

[0181] Examples of quinone diazides include a 5-naphthoquinone diazide sulfonyl group, a 4-naphthoquinone diazide sulfonyl group, and those containing a 4-naphthoquinone diazide sulfonyl group and a 5-naphthoquinone diazide sulfonyl group in the same molecule.

[0182] Examples of naphthoquinone diazide sulfonyl ester compounds include 5-naphthoquinone diazide sulfonyl ester compound (B-1) and 4-naphthoquinone diazide sulfonyl ester compound (B-2). In the present invention, however, it is preferable to include compound (B-1). Compound (B-1) has an absorption extending into the g-line region of a mercury lamp, making it suitable for g-line exposure and full-wavelength exposure. Furthermore, upon curing, it reacts with resin (A) and the like to form a crosslinked structure, improving chemical resistance. Furthermore, since it exhibits less coloration after heat treatment than compound (B-2), it is also preferable from the viewpoint of light transmittance after heat treatment. The content of compound (B-1) is preferably 55% by mass or more and 100% by mass or less of the total photosensitizer amount (compound (B-1) + compound (B-2)). This content ratio allows for the production of a cured film with high light transmittance.

[0183] The quinone diazide compound can be synthesized by a known method through an esterification reaction between a compound having a phenolic hydroxyl group and a quinone diazide sulfonic acid compound. The use of the quinone diazide compound further improves resolution, sensitivity, and film retention.

[0184] The molecular weight of the (B) photosensitizer is preferably 300 or more, more preferably 350 or more, and is preferably 3,000 or less, more preferably 1,500 or less, from the viewpoint of the heat resistance, mechanical properties, and adhesiveness of the film obtained by heat treatment.

[0185] Of the photosensitizers (B), sulfonium salts, phosphonium salts, and diazonium salts are preferred because they appropriately stabilize the acid component generated by exposure, with sulfonium salts being particularly preferred.

[0186] The content of the (B) photosensitizer is preferably 0.1 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the (A) resin. When the content of the (B) photosensitizer is 0.1 parts by mass or more and 100 parts by mass or less, photosensitivity can be imparted while maintaining the heat resistance, chemical resistance, and mechanical properties of the film after heat treatment.

[0187] When the (B) photosensitizer contains a quinone diazide compound, the content of the (B) photosensitizer is preferably 1 part by mass or more, and even more preferably 3 parts by mass or more, relative to 100 parts by mass of the (A) resin. Also, the content is more preferably 100 parts by mass or less, and even more preferably 80 parts by mass or less. When the content is 1 part by mass or more and 100 parts by mass or less, photosensitivity can be imparted while maintaining the heat resistance, chemical resistance, and mechanical properties of the film after heat treatment.

[0188] When the (B) photosensitizer contains a sulfonium salt, a phosphonium salt, or a diazonium salt, the content of the (B) photosensitizer is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and particularly preferably 3 parts by mass or more, relative to 100 parts by mass of the (A) resin. Also, it is more preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and particularly preferably 50 parts by mass or less. If it is 0.1 parts by mass or more and 100 parts by mass or less, it is possible to impart photosensitivity while maintaining the heat resistance, chemical resistance, and mechanical properties of the film after heat treatment.

[0189] When a photobase generator is contained as the photosensitizer (B), specific examples of the photobase generator include amide compounds and ammonium salts.

[0190] Examples of the amide compound include 2-nitrophenylmethyl-4-methacryloyloxypiperidine-1-carboxylate, 9-anthrylmethyl-N,N-dimethylcarbamate, 1-(anthraquinone-2yl)ethylimidazolecarboxylate, and (E)-1-[3-(2-hydroxyphenyl)-2-propenoyl]piperidine.

[0191] Examples of ammonium salts include 1,2-diisopropyl-3-(bisdimethylamino)methylene)guanidinium 2-(3-benzoylphenyl)propionate, (Z)-{[bis(dimethylamino)methylidene]amino}-N-cyclohexylamino)methaniminium tetrakis(3-fluorophenyl)borate, and 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguanidinium n-butyltriphenylborate.

[0192] When a photobase generator is contained as the (B) photosensitizer, the content of the (B) photosensitizer in the resin composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.7 parts by mass or more, and particularly preferably 1 part by mass or more, relative to 100 parts by mass of the (A) resin. When the content is within the above range, the sensitivity during exposure can be improved. On the other hand, the content is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 17 parts by mass or less, and particularly preferably 15 parts by mass or less. When the content is within the above range, the resolution after development can be improved.

[0193] When a photopolymerization initiator is contained as the (B) photosensitizer, preferred examples of the photopolymerization initiator include benzyl ketal-based photopolymerization initiators, α-hydroxyketone-based photopolymerization initiators, α-aminoketone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, oxime ester-based photopolymerization initiators, acridine-based photopolymerization initiators, benzophenone-based photopolymerization initiators, acetophenone-based photopolymerization initiators, aromatic ketoester-based photopolymerization initiators or benzoate ester-based photopolymerization initiators, and titanocene-based photopolymerization initiators. Known photopolymerization initiators may be used, or a plurality of such initiators may be used. Among these, from the viewpoint of improving sensitivity during exposure, an α-hydroxyketone-based photopolymerization initiator, an α-aminoketone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, an oxime ester-based photopolymerization initiator, an acridine-based photopolymerization initiator, or a benzophenone-based photopolymerization initiator is more preferable, and an α-aminoketone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, or an oxime ester-based photopolymerization initiator is even more preferable.

[0194] When a photopolymerization initiator (B) is contained as the photosensitizer, the content of the photosensitizer (B) in the resin composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.7 parts by mass or more, and particularly preferably 1 part by mass or more, relative to 100 parts by mass of the resin (A). When the content is within the above range, the sensitivity during exposure can be improved. On the other hand, the content is preferably 25 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 17 parts by mass or less, and particularly preferably 15 parts by mass or less. When the content is within the above range, the resolution after development can be improved.

[0195] In the present invention, the resin composition containing the resin (A) preferably contains a thermal crosslinking agent (C) (hereinafter, sometimes referred to as component (C)). The thermal crosslinking agent refers to a resin or compound having at least two thermally reactive functional groups in the molecule. Examples of the thermally reactive functional group include compounds having an alkoxymethyl group, a methylol group, a cyclic ether group, or the like.

[0196] In the present invention, it is preferable to contain the thermal crosslinking agent (C) since this improves chemical resistance.

[0197] In the present invention, a cured film obtained by curing a resin composition containing (A) resin, (B) photosensitizer, and (C) thermal crosslinker has a light transmittance of 80% or more and 100% or less at a wavelength of 450 nm at a thickness of 5 μm. This prevents light emitted in all directions from the light-emitting element from being absorbed in the cured film obtained by curing a resin composition containing (A) resin, (B) photosensitizer, and (C) thermal crosslinker, thereby increasing the light extraction efficiency and improving the brightness.

[0198] In order to obtain such properties, the (C) thermal crosslinking agent is preferably one that has high light transmittance at 450 nm itself and high heat resistance, and that forms little, for example, a quinone structure, which is one of colored structures, or one that forms a reaction product between the (B) photosensitizer and the (A) resin or the like with high light transmittance, or one that forms a decomposition product of the (C) thermal crosslinking agent itself or a reaction product derived from the decomposition product with high light transmittance.

[0199] The thermal crosslinking agent may contain one or more compounds selected from alkoxymethyl compounds and methylol compounds (hereinafter, sometimes abbreviated as component (C-1)). The inclusion of component (C-1) strengthens the crosslinking, further improving the chemical resistance of the cured film to, for example, flux solutions. Specific examples of component (C-1) include the following methylol compounds, or alkoxymethyl compounds in which the hydrogen atom of the methylol group is substituted with a methyl group or an alkyl group having 2 to 10 carbon atoms, but are not limited to the structures shown below.

[0200]

[0201]

[0202] The thermal crosslinking agent (C) may contain one or more cyclic ether group compounds (hereinafter, sometimes abbreviated as component (C-2)). By including component (C-2), the reaction can proceed even at low temperatures of 160°C or less, and the crosslinking can be made stronger, thereby further improving the chemical resistance of the cured film.

[0203] Specific examples of the component (C-2) include Denacol (registered trademark) EX-212L, Denacol EX-214L, Denacol EX-216L, Denacol EX-850L, and Denacol EX-321L (all manufactured by Nagase ChemteX Corporation), GAN, and GOT (all manufactured by Nippon Kayaku Co., Ltd.), Epicoat (registered trademark) 828, Epicoat 1002, Epicoat 1750, Epicoat 1007, and YX4. 000, YX4000H, YX8100-BH30, E1256, E4250, E4275 (all manufactured by Mitsubishi Chemical Corporation), "Epicron (registered trademark)" 850-S, Epicron HP-4032, Epicron HP-7200, Epicron HP-820, Epicron HP-4700, Epicron HP-4770, Epicron HP4032 (all manufactured by Dainippon Ink and Chemicals, Inc.), TECHMORE Examples of suitable acrylic resins include VG3101L (manufactured by Printec Co., Ltd.), Tepic (registered trademark) S, Tepic G, and Tepic P (all manufactured by Nissan Chemical Industries, Ltd.), Epotohto YH-434L (manufactured by Tohto Kasei Co., Ltd.), EPPN502H, NC-3000, NC-6000, and XD-1000 (manufactured by Nippon Kayaku Co., Ltd.), Epiclon N695 and HP7200 (manufactured by Dainippon Ink and Chemicals, Inc.), Etanacol (registered trademark) EHO, Etanacol OXBP, Etanacol OXTP, and Etanacol OXMA (all manufactured by Ube Industries, Ltd.), and oxetanized phenol novolak.

[0204] Among these, those having a triarylmethane structure or a biphenyl structure are preferred, and specific examples include YX4000, YX4000H (both manufactured by Mitsubishi Chemical Corporation), TECHMORE VG3101L (manufactured by Printec Co., Ltd.), and NC-3000.

[0205] Furthermore, the thermal crosslinking agent (C) may contain one or more compounds containing a structural unit represented by the following general formula (5) (hereinafter, sometimes abbreviated as component (C-3)):

[0206]

[0207] In general formula (5), R ２５R is a divalent organic group having an alkylene group or an alkylene ether group having 1 to 15 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, an ethylene oxide group, a propylene oxide group, or a butylene oxide group, and may be linear, branched, or cyclic. Furthermore, some of the substituents of the divalent organic group having an alkylene group or an alkylene ether group having 1 to 15 carbon atoms may have a cyclic ether group, an alkylsilyl group, an alkoxysilyl group, an aryl group, an aryl ether group, a carboxy group, a carbonyl group, an allyl group, a vinyl group, a heterocyclic group, or other substituents, or may be a combination thereof. ２６ and R ２７ each independently represents a hydrogen atom or a methyl group.

[0208] The component (C-3) itself contains a flexible alkylene group and a rigid aromatic group. Therefore, by including the component (C-3), the resulting cured film can have improved elongation and reduced stress while maintaining heat resistance.

[0209] Examples of crosslinking groups contained in component (C-3) include, but are not limited to, acrylic groups, methylol groups, alkoxymethyl groups, cyclic ether groups, etc. Among these, cyclic ether groups are preferred because they react with hydroxyl groups in resin (A) to improve the heat resistance of the cured film and can react without dehydration.

[0210] Specific examples of compounds containing a structural unit represented by general formula (5) include, but are not limited to, the following structures:

[0211]

[0212] o during the ceremony １ is an integer from 1 to 20, o ２ is an integer of 1 to 5. In order to achieve both heat resistance and improved elongation, １ is an integer from 3 to 7, o ２ is preferably an integer of 1 or 2.

[0213] The thermal crosslinking agent (C) may be used in combination of two or more kinds.

[0214] The content of the (C) thermal crosslinking agent is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more, per 100 parts by mass of the (A) resin, from the viewpoint of obtaining a cured film having high chemical resistance to, for example, flux liquid, while maintaining the storage stability of the resin composition, and further from the viewpoint of being able to suppress peeling from the wiring and cracking of the cured film after a reliability test of the wiring to which the cured film is applied, the content is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 80 parts by mass or less, per 100 parts by mass of the (A) resin.

[0215] The resin composition containing the (A) resin may contain, as necessary, other components such as a radical polymerizable compound, an antioxidant, a solvent, a compound having a phenolic hydroxyl group, an adhesion improver, a bonding improver, or a surfactant.

[0216] Next, a method for producing the resin composition of the present invention will be described. For example, the resin composition can be obtained by mixing and dissolving the resin (A) and, if necessary, the photosensitizer (B), the thermal crosslinking agent (C), each radical polymerizable compound, an antioxidant, a solvent, a compound having a phenolic hydroxyl group, an adhesion improver, an adhesion improver, a surfactant, and the like.

[0217] The dissolution method may be a known method such as heating or stirring.

[0218] The viscosity of the resin composition is preferably 2 to 5,000 mPa·s. By adjusting the solid content concentration so that the viscosity is 2 mPa·s or more, it is easy to obtain a desired film thickness. On the other hand, if the viscosity is 5,000 mPa·s or less, it is easy to obtain a highly uniform resin film. A resin composition having such a viscosity can be easily obtained, for example, by adjusting the solid content concentration to 5 to 60 mass%. Here, the solid content concentration refers to the components other than the solvent.

[0219] The resulting resin composition is preferably filtered using a filter to remove dust and particles. Filter materials include polypropylene (PP), polyethylene (PE), nylon (NY), and polytetrafluoroethylene (PTFE), with polyethylene and nylon being preferred.

[0220] When forming a cured film by curing a resin composition containing the (A) resin, a resin sheet may be formed from the resin composition containing the (A) resin, and then the resin sheet may be cured to form a film.

[0221] The resin sheet refers to a sheet formed on a substrate using the resin composition, specifically, a resin sheet obtained by applying the resin composition to a substrate and drying it.

[0222] A film such as polyethylene terephthalate (PET) can be used as the substrate to which the resin composition is applied. When the resin sheet is used by being attached to a substrate such as a silicon wafer, if it is necessary to peel and remove the substrate, it is preferable to use a substrate whose surface is coated with a release agent such as a silicone resin, because this allows the resin sheet to be easily peeled from the substrate.

[0223] Next, a method for manufacturing the display device of the present invention will be described.

[0224] The method for manufacturing a display device of the present invention is a method for manufacturing a display device having at least wiring, a cured film, and light-emitting elements each having electrodes on two different surfaces, and includes the steps of: (D1) arranging the light-emitting elements on a supporting substrate; (D2) forming a resin film made of a resin composition containing a resin (A) on the supporting substrate and the light-emitting elements; (D3) exposing and developing the resin film to form a pattern of a plurality of through-holes in the resin film; (D4) curing the resin film to form the cured film having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a thickness of 5 μm; and (D5) forming the wiring on at least a portion of the surface of the cured film and in the opening pattern of the cured film.

[0225] FIG. 11 is a cross-sectional view taken along a plane perpendicular to a supporting substrate, showing an example of a manufacturing process of a display device having a plurality of light-emitting elements according to the present invention.

[0226] Hereinafter, the term "resin film" refers to a film obtained by applying a resin composition containing (A) resin to a substrate or laminating a resin sheet thereon and drying it. Here, a resin composition containing (A) resin that contains a solvent may also be referred to as a "varnish." Furthermore, the term "cured film" refers to a resin film or a film obtained by curing a resin sheet.

[0227] In FIG. 11a, step (D1) is a step of disposing a light-emitting element 2 having electrodes 6 on two different surfaces on a support substrate 20. The support substrate may be, but is not limited to, a glass substrate, a silicon substrate, a ceramic substrate, gallium arsenide, an organic circuit substrate, an inorganic circuit substrate, or a substrate having a circuit component disposed thereon. A temporary bonding material or wiring 4d may be disposed on the support substrate. A TFT array substrate may also be used. The support substrate may be used as a counter substrate or a light-emitting element driving substrate, or may be removed during the process. After removal, a different counter substrate or light-emitting element driving substrate may be disposed. FIG. 11a illustrates an example in which a temporary bonding layer is formed on the support substrate 20 and wiring 4d is formed thereon. The electrode 6 and wiring 4d may be connected via a bump, a conductive film, or the like, or may be directly connected. Furthermore, the wiring 4d may be connected to wiring 4 extending through a cured film 3 arranged so as to contact at least a portion of the light-emitting element 2 via a through-electrode or the like, or may be connected to a light-emitting element driving substrate 7.

[0228] Next, step (D2) is a step of forming a resin film 21 by applying or laminating a resin composition containing (A) resin or a resin sheet formed from a resin composition containing (A) resin onto a support substrate 20 and onto a light-emitting element 2, as shown in Figure 11b.

[0229] Note that "on the support substrate and on the light-emitting element" does not only refer to the surface of the support substrate or the surface of the light-emitting element, but also to the upper side of the support substrate or the light-emitting element, and a resin film may be formed by applying or laminating a resin composition containing the (A) resin or a resin sheet formed from a resin composition containing the (A) resin onto a cured film, wiring, a reflective film, or a partition wall.

[0230] Examples of the coating method include spin coating, slit coating, dip coating, spray coating, printing, etc. The coating thickness varies depending on the coating method, the solids concentration of the composition, the viscosity, etc., but the coating is usually carried out so that the film thickness after drying will be 0.1 to 150 μm.

[0231] Prior to coating, the support substrate to which the resin composition containing the resin (A) is to be applied may be pretreated with the adhesion promoter described above. For example, the substrate surface may be treated by spin coating, slit die coating, bar coating, dip coating, spray coating, steam treatment, or the like using a solution in which 0.5 to 20% by mass of the adhesion promoter is dissolved in a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, or diethyl adipate. After the substrate surface treatment, a reduced pressure drying treatment may be performed as necessary. Furthermore, the reaction between the substrate and the adhesion promoter may then be promoted by heat treatment at 50°C to 280°C.

[0232] Next, the coated film of the resin composition containing the (A) resin is dried to obtain the resin film 21. Drying is preferably carried out using an oven, a hot plate, infrared rays, or the like at a temperature in the range of 50°C to 140°C for 1 minute to several hours.

[0233] On the other hand, when the resin sheet is used, if the resin sheet has a protective film, the protective film is peeled off, and the resin sheet and a support substrate are placed opposite each other and bonded together by thermocompression (placing the resin sheet and the support substrate opposite each other and bonding them together by thermocompression is sometimes referred to as laminating the resin sheet to the support substrate). Next, the resin sheet laminated to the support substrate is dried in the same manner as when obtaining the resin film, to form resin film 21. The resin sheet can be obtained by applying a resin composition containing resin (A) to a support film made of polyethylene terephthalate or the like, which is a peelable substrate, and drying the applied composition.

[0234] Thermocompression bonding can be performed by heat pressing, heat lamination, thermal vacuum lamination, etc. The lamination temperature is preferably 40°C or higher in terms of adhesion to the substrate and embeddability. Furthermore, when the resin sheet is photosensitive, the lamination temperature is preferably 140°C or lower to prevent the resin sheet from curing during lamination, which would reduce the resolution of pattern formation in the exposure and development steps.

[0235] Next, in step (D3), a penetrating opening pattern 12 corresponding to the shape of the wiring 4 is formed in the resin film 21 by photolithography, as shown in FIG. 11c.

[0236] (A) A resin composition or a resin sheet containing the resin can be microfabricated, allowing light-emitting elements to be arranged at high density.

[0237] The photosensitive resin film is irradiated with actinic radiation through a mask having a desired pattern. Actinic radiation used for exposure includes ultraviolet light, visible light, electron beams, X-rays, etc., but in the present invention, it is preferable to use g-rays (436 nm), h-rays (405 nm), or i-rays (365 nm), which are common exposure wavelengths. For non-photosensitive resin films, a photoresist is formed after the resin film is formed, and then the actinic radiation is irradiated.

[0238] The exposed photosensitive resin film 21 is developed. Preferred developing solutions include aqueous solutions of alkaline compounds such as tetramethylammonium, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, and hexamethylenediamine. In some cases, these alkaline aqueous solutions may contain one or more polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, and dimethylacrylamide; alcohols such as methanol, ethanol, and isopropanol; esters such as ethyl lactate and propylene glycol monomethyl ether acetate; and ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, and methyl isobutyl ketone. After development, the resulting film is typically rinsed with water. Here too, rinsing treatment may be carried out by adding alcohols such as ethanol and isopropyl alcohol, or esters such as ethyl lactate and propylene glycol monomethyl ether acetate to water.

[0239] Next, in step (D4), the resin film 21 shown in FIG. 11c is cured to form a cured film 3 having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a thickness of 5 μm.

[0240] The resin film 21 is heated to promote ring-closing reactions and thermal crosslinking reactions, yielding a cured film 3. The cured film 3 has improved heat resistance and chemical resistance due to crosslinking between (A) resins, (B) photosensitizers, and (C) thermal crosslinking agents. This heat treatment may be performed by gradually increasing the temperature or by continuously increasing the temperature. The heat treatment is preferably performed for 5 minutes to 5 hours. An example includes a 30-minute heat treatment at 110°C, followed by a further 60-minute heat treatment at 230°C. Heat treatment conditions are preferably 140°C or higher and 400°C or lower. To promote the thermal crosslinking reaction, a heat treatment temperature of 140°C or higher is preferred, with 160°C or higher being more preferred. Furthermore, to provide an excellent cured film and improve the reliability of display devices, heat treatment conditions are preferably 300°C or lower, with 250°C or lower being more preferred.

[0241] In order to obtain a cured film having high transmittance to light with a wavelength of 450 nm at a standard thickness of 5 μm, the heating is preferably carried out in an atmosphere with a low oxygen concentration, preferably 1000 ppm or less, more preferably 300 ppm or less, and even more preferably 50 ppm or less.

[0242] The cured film thus obtained has an opening pattern, and the angle of the inclined side in the cross section of the opening pattern is preferably 40° or more and 85° or less. When the angle of the cross-sectional shape of the opening is 40° or more, multiple light-emitting elements can be arranged efficiently, enabling high definition. The angle of the cross-sectional shape of the opening is more preferably 50° or more. On the other hand, when the angle of the cross-sectional shape of the opening is 85° or less, wiring defects such as wiring short circuits can be suppressed. The angle of the cross-sectional shape of the opening is more preferably 80° or less.

[0243] Fig. 22 shows a cross-sectional view of the opening pattern of the cured film taken along a plane perpendicular to the support base. In Fig. 22, the angle of the inclined side 27 of the opening pattern formed in the cured film 3 is 28. The inclined side is a straight line connecting the opening pattern at a position 30 that is halfway along the thickness direction of the cured film 3 and the opening pattern at the bottom.

[0244] Next, in FIG. 11c, in order to improve the adhesion between the hardened film 3 and the wiring 4, a barrier metal such as titanium is sputtered on the hardened film 3, and a copper seed (seed layer) is further formed on top of that by sputtering.

[0245] 11d, in step (D5), after forming a photoresist layer (not shown), wiring 4 made of a metal such as copper or a conductive film for electrically connecting to at least one electrode 6 of the light-emitting element 2 is formed on the opening pattern 12 of the cured film 3 and on a part of the surface of the cured film 3 by plating, sputtering, processing a photosensitive conductive paste, etc. Then, unnecessary photoresist, seed layer, and barrier metal are removed.

[0246] This allows the cured film to ensure electrical insulation of the wiring, and extending the wiring through the cured film electrically connects the electrodes of the light-emitting element and the driving element, thereby controlling the light-emitting operation. Furthermore, the cured film has a high light transmittance at a wavelength of 450 nm at a standard thickness of 5 μm, which prevents absorption of light emitted from the light-emitting element and improves light extraction.

[0247] The method for producing a display device of the present invention preferably includes a step of repeating the steps (D2), (D3), (D4), and (D5) multiple times to form multiple layers of the cured film having the wiring therein.

[0248] As shown in FIGS. 11e and 11f, the hardened film 3 and the wiring 4 can be formed by repeating the same method again to form a hardened film 3 consisting of two or more layers.

[0249] This allows for the arrangement of multiple light-emitting elements by using multiple layers of cured films having wiring therein, and also makes it possible to suppress wiring defects such as short circuits in the wiring due to a reduced package height and a shorter wiring distance, reduce loss, and improve high-speed response.

[0250] 11g, a barrier metal 9 is formed in the opening pattern 12 of the cured film 3 by sputtering to form a bump 10. The barrier metal 9 may or may not be present.

[0251] 11h, the wiring 4 is electrically connected to a light-emitting element drive substrate 7 having drive elements 8 such as a driver IC via bumps 10, the support substrate 20 is peeled off, and the opposing substrate 5 is attached using an adhesive or the like to obtain a display device 1 having a plurality of light-emitting elements 2. The wiring 4 may include electrodes.

[0252] One or more driving elements 8 may be used for one light-emitting element 2, one unit of light-emitting elements 2 consisting of red, blue, and green, or for multiple light-emitting elements 2 or multiple units of light-emitting elements 2, depending on the function, and for example, one or more driving elements may be disposed near the light-emitting elements during the process of Fig. 11. In this case, the driving element is electrically connected to the light-emitting element 2 via the light-emitting element driving substrate 7, the wiring 4c, the wiring 4 extending into the cured film 3, etc.

[0253] This allows the cured film to ensure electrical insulation of the wiring, and extending the wiring through the cured film electrically connects the electrodes of the light-emitting element and the driving element, thereby controlling the light-emitting operation. Furthermore, the cured film has a high light transmittance at a wavelength of 450 nm at a standard thickness of 5 μm, which prevents absorption of light emitted from the light-emitting element and improves light extraction.

[0254] The method for manufacturing a display device may include a step (D6) of exposing the entire region of the resin film to light after the step (D3) and before the step (D4). By exposing the resin film after development, coloring during heat treatment can be suppressed and the transmittance of light with a wavelength of 450 nm after heat treatment can be improved. In particular, it is particularly preferable to use a photoacid generator as the photosensitizer (B).

[0255] The manufacturing method of the display device of the present invention preferably includes, before step (D1), step (D7) of providing partition walls having a thickness equal to or greater than that of the light-emitting element 2. An example of step (D7) is shown in FIG. 12. FIG. 12a illustrates step (D7) of providing partition walls 16 having a thickness equal to or greater than that of the light-emitting element 2 on a support substrate, and the following FIG. 12b illustrates step (D1) of providing a plurality of light-emitting elements 2 between partition walls having a thickness equal to or greater than that of the light-emitting element 2. FIG. 12c illustrates a step of disposing a resin film 21, similar to step (D2) shown in FIG. 11b, while leaving the partition walls 16 in place. The subsequent steps are carried out as shown in FIG. 11. The partition walls may be made of resin (A), or may be made of known materials such as epoxy resin, (meth)acrylic polymer, polyurethane, polyester, polyolefin, or polysiloxane. Light-shielding or reflective portions may also be provided.

[0256] The method for producing a display device of the present invention preferably includes, after the step (D4), a step (D8) of providing a reflective film on a part of the cured film.

[0257] An example of the step (D8) is shown in Fig. 13. Fig. 13d shows the step (D8) of providing a reflective film 15 on a partial region of the cured film 3.

[0258] The steps up to Fig. 13d are the same as those up to step (D4) in Fig. 11c, and the next step in Fig. 13e shows step (D5) of forming the same wiring 4 as in Fig. 11d. The subsequent steps are carried out in the order of the steps shown in Fig. 11, with the reflective film 15 remaining in place. The reflective film is formed by a method such as sputtering using aluminum, silver, copper, titanium, or an alloy containing any of these. It is also preferable to protect the relevant portion with a photoresist or the like in advance so that it does not overlap with the wiring to be formed later, or to perform sputtering using a predetermined mask.

[0259] In the manufacturing method of the display device of the present invention, after the step (D5), it is preferable to further include a step (D9) of having a driving element and a substrate, the driving element being connected to the light-emitting element through wiring, and at least a portion of the wiring extending to the side of the substrate.

[0260] An example of step (D9) is shown in Figure 11. Figure 11h shows step (D9) having a driving element and a substrate, and the driving element is connected to the light-emitting element through wiring. As shown in Figure 11h, the driving element is connected to the light-emitting element 2 through wiring 4 and 4c, and part of the wiring 4c extends to the side surface of the light-emitting element driving substrate 7. If the light-emitting element driving substrate 7 has a through electrode, it may be connected to the driving element 8 through the through electrode.

[0261] This allows the display device itself to be made lower in height and have improved high-speed response, and further allows the display device to be made smaller and have a narrower frame.

[0262] The method for producing a display device of the present invention preferably further comprises the step (D10) of providing a light-shielding layer between the plurality of light-emitting elements.

[0263] An example of step (D10) is shown in Fig. 23. Fig. 23a shows step (D10) of providing a light-shielding layer 26 between a plurality of light-emitting elements 2. The light-shielding layer 26 may be formed before or after the light-emitting elements 2 are formed.

[0264] The light-shielding layer 26 may be composed of a cured film obtained by curing a resin composition containing (A) resin and (E) colorant. Alternatively, it may be composed of a material other than the resin composition containing (A), such as known materials such as epoxy resin, (meth)acrylic polymer, polyurethane, polyester, polyolefin, and polysiloxane. The (E) colorant may be a black pigment, such as black organic pigments such as carbon black, perylene black, and aniline black; graphite; and inorganic pigments such as metal fine particles of titanium, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, and silver, metal oxides, composite oxides, metal sulfides, metal nitrides, and metal oxynitrides. Furthermore, a black color may be achieved by combining a red pigment and a blue pigment, or, if necessary, a yellow pigment or other pigment. Dyes may also be used. Two or more colorants may be used.

[0265] Furthermore, the resin composition containing the resin (A) and the colorant (E) may be made photosensitive, and a photosensitizer (B) described below may be used.

[0266] As a method for forming the light-shielding layer, if the light-shielding layer is photosensitive, a photolithography process may be used. If the light-shielding layer is not photosensitive, a photolithography process or an etching process may be used after forming a photoresist on the light-shielding layer, or an etching process using a mask may be used. A patterned colored film can be obtained by subjecting the obtained pattern to a heat treatment (post-baking). The heat treatment may be performed in air, a nitrogen atmosphere, or a vacuum. The heating temperature is preferably 100 to 300°C, and the heating time is preferably 0.25 to 5 hours. The heating temperature may be changed continuously or in steps.

[0267] The method for manufacturing a display device of the present invention is a method for manufacturing a display device having at least wiring, a cured film, and light-emitting elements each having electrodes on two different surfaces, and includes the steps of: (E1) arranging pads on a support substrate; (E2) forming a resin film made of a resin composition containing a resin (A) on the support substrate and the pads; (E3) forming a pattern of a plurality of through-holes in the resin film by exposing and developing the resin film; (E4) curing the resin film to form the cured film having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a thickness of 5 μm; (E5) forming the wiring on at least a portion of the surface of the cured film and in the opening pattern of the cured film; and (E6) arranging the light-emitting elements on the cured film so as to maintain electrical connection with the wiring.

[0268] 14 shows a cross-sectional view of a plane perpendicular to the support substrate or the opposing substrate, illustrating another example of a manufacturing process for the display device 1 of the present invention. Since the process overlaps with that of FIG. 11, specifically, FIG. 14b to FIG. 14e overlaps with FIG. 11b to FIG. 11f, the explanation is omitted.

[0269] 14a, the step (E1) is a step of arranging pads 18 on a support substrate 20. The pads may be made of copper or aluminum.

[0270] Next, in step (E2), as shown in Fig. 14b, a resin composition or a resin sheet containing the (A) resin is applied or laminated onto the support substrate 20 and the pads 18 to form a resin film 21. Note that "on the support substrate" and "on the pads" does not only mean the surface of the support substrate or the surface of the pads, but also means the upper side of the support substrate or the pads, and the resin film may be formed by applying or laminating the resin composition containing the (A) resin or a resin sheet formed from the resin composition containing the (A) resin onto a cured film, wiring, a reflective film, or a partition wall.

[0271] Next, in step (E3), as shown in FIG. 14c, a plurality of penetrating opening patterns 12 are formed in resin film 21 using a photolithography process.

[0272] Next, in step (E4), as shown in FIG. 14c, the resin film 21 is cured to form a cured film 3 having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a thickness of 5 μm.

[0273] Next, in FIG. 14c, in order to improve the adhesion between the hardened film 3 and the wiring 4, a barrier metal such as titanium is sputtered on the hardened film 3, and a copper seed (seed layer) is further formed on top of that by sputtering.

[0274] 14d, in step (E5), after forming a photoresist layer (not shown), wiring 4 made of copper, a conductive film, or the like is formed on the opening pattern 12 of the cured film 3 and on a part of the surface of the cured film 3 by plating, sputtering, processing a photosensitive conductive paste, or the like. Thereafter, unnecessary photoresist, seed layer, and barrier metal are removed.

[0275] The method for manufacturing a display device of the present invention preferably includes a step of repeating the steps (E2), (E3), (E4), and (E5) multiple times to form multiple layers of the cured film having the wiring therein.

[0276] As shown in FIGS. 14b to 14d, the hardened film 3 and the wiring 4 can be repeatedly formed in the same manner to form a hardened film 3 consisting of two or more layers as shown in FIG. 14e.

[0277] Next, in step (E6), as shown in Fig. 14f, the light-emitting element 2 is disposed on the cured film 3 so as to maintain electrical connection with the wiring 4. The electrode 6 of the light-emitting element 2 may be directly connected to the wiring 4, or may be connected via, for example, a bump or a conductive film.

[0278] 14g, it is preferable to have a step (E7) of forming a cured film 22 on the cured film 3 and the light-emitting element 2. The cured film 22 is preferably formed by applying a resin composition containing the (A) resin or laminating a resin sheet made of the resin composition containing the (A) resin to form a resin film made of the resin composition, and curing the resin film to form the cured film 22. The cured film 22 may also be made of a material other than the resin composition containing the (A) resin and the (B) photosensitizer, and known materials such as epoxy resin, silicone resin, and fluororesin may also be used.

[0279] Curing conditions vary depending on the type of resin, but examples include 80°C to 230°C and 15 minutes to 5 hours. The purpose of forming a cured film on the light-emitting element is to protect and flatten the light-emitting element. Figure 14g illustrates an example in which wiring 4d is formed on the cured film 22 after it has been formed. The electrode 6 and wiring 4d may be connected via a bump, a conductive film, or the like, or may be connected directly. Furthermore, the wiring 4d may be connected to wiring 4 extending through the cured film 3 arranged so as to contact at least a portion of the light-emitting element 2 via a through-electrode or the like, or may be connected to the light-emitting element driving substrate 7.

[0280] 14h, the opposing substrate 5 is bonded to the cured film 22 using an adhesive or the like. The support substrate 20 is then peeled off, and a barrier metal 9 and bumps 10 are formed, which are electrically connected via the bumps 10 to a light-emitting element drive substrate 7 to which drive elements 8 such as driver ICs are attached.

[0281] The driving elements 8 are electrically connected to the light-emitting elements 2 via wiring 4 extending into the cured film 3, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. The wiring 4 may include electrodes.

[0282] The driving element 8 may be used singly or in plural for a single light-emitting element 2, for a single unit of light-emitting elements 2 consisting of red, blue, and green light-emitting elements, for multiple light-emitting elements 2, or for multiple units of light-emitting elements 2, depending on the function. For example, one or more driving elements may be disposed near the light-emitting elements during the process shown in FIG. 14 . In this case, the driving element is electrically connected to the light-emitting element 2 via the light-emitting element driving substrate 7, wiring 4c, wiring 4 extending into the cured film 3, etc. This ensures electrical insulation of the wiring through the cured film, and extending the wiring through the cured film electrically connects the electrodes of the light-emitting element to the driving element, thereby controlling the light-emitting operation. Furthermore, the cured film has a high optical transmittance at a wavelength of 450 nm at a thickness of 5 μm, which suppresses absorption of light emitted from the light-emitting element and improves light extraction.

[0283] The method for manufacturing a display device of the present invention preferably includes a step (E8) of exposing the entire region of the resin layer to light after the step (E3) and before the step (E4). By exposing the resin layer after development, coloring during heat treatment can be suppressed and the light transmittance at a wavelength of 450 nm after heat treatment can be improved. This is particularly preferable when a photoacid generator is used as the photosensitizer (B).

[0284] The method for producing a display device of the present invention preferably includes, after the step (E5), a step (E9) of providing a partition wall having a thickness equal to or greater than the thickness of the light-emitting element.

[0285] An example of step (E9) is shown in Figure 15. Figure 15f shows step (E9) of forming multiple layers of the cured film 3 shown in Figure 14e and then providing partition walls 16. Thereafter, as shown in Figure 15g, light-emitting elements 2 are provided between the partition walls 16. Next, as shown in Figure 15h, wiring 4d and electrodes 6 are electrically connected. Also, an opposing substrate 5 is attached to the upper part of the partition walls 16 and the light-emitting elements 2, and the support substrate 20 is peeled off. A barrier metal 9 and bumps 10 are formed, and the light-emitting elements are electrically connected to a light-emitting element drive substrate 7 having drive elements 8 such as a driver IC via the bumps 10.

[0286] The method for manufacturing a display device of the present invention preferably includes a step (E10) of providing a reflective film on a part of the cured film after the step (E5) and before the step (E6).

[0287] An example of step (E10) is shown in Fig. 16. Fig. 16f shows step (E10) of providing a reflective film 15 after forming multiple layers of the cured film 3 shown in Fig. 14e. The subsequent steps are carried out in the order of the steps shown in Fig. 14f, Fig. 14g, and Fig. 14h, with the reflective film 15 remaining in place.

[0288] Preferably, the method for manufacturing a display device of the present invention further includes, after step (E7), step (E11) of providing a driving element and a substrate, the driving element being connected to the light-emitting element through wiring, and at least a portion of the wiring extending to the side of the substrate.

[0289] An example of step (E11) is shown in Figure 14. Figure 14h shows step (E11) in which a driving element and a substrate are provided, and the driving element is connected to the light-emitting element through wiring. As shown in Figure 14h, the driving element is connected to the light-emitting element 2 through wiring 4 and 4c, and part of the wiring 4c extends to the side surface of the light-emitting element driving substrate 7. If the light-emitting element driving substrate 7 has a through electrode, it may be connected to the driving element 8 through the through electrode.

[0290] This allows the display device itself to be made lower in height and have improved high-speed response, and further allows the display device to be made smaller and have a narrower frame.

[0291] The method for manufacturing a display device of the present invention is a method for manufacturing a display device having at least wiring, a cured film, and light-emitting elements each having an electrode on two different surfaces, and may include the steps of: (F1) forming a resin film made of a resin composition containing a resin (A) on a substrate or the like; (F2) exposing and developing the resin film to form a pattern of openings that penetrate the resin film; (F3) curing the resin film to form the cured film having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a standard thickness of 5 μm; (F4) forming the wiring on at least a portion of the surface of the cured film and on a portion of the opening pattern of the cured film; and (F5) arranging the light-emitting elements on the cured film so as to maintain electrical connection with the wiring.

[0292] FIG. 24 is a cross-sectional view taken along a plane perpendicular to the light-emitting element driving substrate, showing an example of a manufacturing process for the display device 1 according to the second embodiment of the present invention.

[0293] 24a, step (F1) is a step of forming a resin film made of a resin composition containing the (A) resin on a substrate, etc. The resin film may be formed by applying or laminating a resin composition containing the (A) resin or a resin sheet formed from a resin composition containing the (A) resin.

[0294] The substrate may be a light-emitting element driving substrate 7. Fig. 24a shows an example of a TFT array substrate in which TFTs 23, an insulating film 24, and wiring 4 are arranged on a glass substrate. The insulating film 24 is not particularly limited, but examples thereof include a silicon oxide film, a silicon nitride film, and an insulating film made of an organic material.

[0295] Next, in step (F2), as shown in FIG. 24a, a plurality of penetrating opening patterns are formed in the resin film using a photolithography process.

[0296] Next, in step (F3), as shown in FIG. 24a, the resin film is cured to form a cured film 3 having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a thickness of 5 μm.

[0297] Next, in step (F4), as shown in Fig. 24b, wiring is formed on at least a portion of the surface of the cured film and on a portion of the opening pattern of the cured film. After forming a photoresist layer (not shown), wiring 4e is formed on the surface of a portion of the cured film 3 by, for example, sputtering or processing a photosensitive conductive paste. Thereafter, unnecessary photoresist is removed.

[0298] Examples of wiring 4e include gold, silver, copper, aluminum, nickel, titanium, molybdenum, alloys containing these, compounds containing as a main component an oxide of at least one element selected from the group consisting of indium, gallium, zinc, tin, titanium, and niobium, and photosensitive conductive pastes containing organic matter and conductive particles, but other known materials may also be used.

[0299] The method for producing a display device of the present invention preferably includes a step of repeating the steps (F1), (F2), (F3), and (F4) multiple times to form multiple layers of the cured film having the wiring therein.

[0300] By repeating the same process again, the hardened film 3 can be formed into two or more layers as shown in Fig. 24c. Thereafter, the wiring 4c is formed.

[0301] Next, in step (F5), as shown in Fig. 24d, the light-emitting element 2 is disposed on the cured film 3 so as to maintain electrical connection with the wiring 4e. The electrode 6 and the wiring 4e may be connected via a bump or a conductive film, or may be connected directly.

[0302] The partition wall 16 may be formed before or after arranging the light-emitting elements 2. Then, the cured film 22 is formed, and the wiring 4d is then formed. The wiring 4d may be connected to the wiring 4, 4e extending in the cured film 3 arranged so as to contact at least a part of the light-emitting elements 2 via a through electrode or the like, or may be connected to the light-emitting element driving substrate 7.

[0303] 24e, an opposing substrate 5 is attached using an adhesive or the like. Furthermore, a driving element 8 such as a driver IC is electrically connected to the light-emitting element 2 via the wiring 4c and the wirings 4 and 4e extending into the cured film 3, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. Note that the wirings 4d and 4e also include electrodes.

[0304] One or more driving elements 8 may be used for one light-emitting element 2, one unit of light-emitting elements 2 consisting of red, blue, and green, or for multiple light-emitting elements 2 or multiple units of light-emitting elements 2, depending on the function, and for example, one or more driving elements may be disposed near the light-emitting elements during the process of Fig. 24. In this case, the driving element is electrically connected to the light-emitting element 2 via the light-emitting element driving substrate 7, wiring 4c, wiring 4 extending into the cured film 3, etc.

[0305] This allows the cured film to ensure electrical insulation of the wiring, and extending the wiring through the cured film electrically connects the electrodes of the light-emitting element and the driving element, thereby controlling the light-emitting operation. Furthermore, the cured film has a high light transmittance at a wavelength of 450 nm at a standard thickness of 5 μm, which prevents absorption of light emitted from the light-emitting element and improves light extraction.

[0306] The method for manufacturing a display device of the present invention is a method for manufacturing a display device having at least wiring, a cured film, and light-emitting elements each having an electrode on two different surfaces, and may include the steps of: (G1) forming a resin film made of a resin composition containing a resin (A) on a substrate or the like; (G2) exposing and developing the resin film to form a pattern of openings that penetrate the resin film; (G3) curing the resin film to form the cured film having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a thickness of 5 μm; (G4) forming the wiring on at least a portion of the surface of the cured film and on a portion of the opening pattern of the cured film; and (G5) arranging the light-emitting elements so as to maintain electrical connection with the wiring.

[0307] FIG. 34 is a cross-sectional view taken along a plane perpendicular to the light-emitting element driving substrate, showing an example of a manufacturing process for the display device 1 according to the second embodiment of the present invention.

[0308] 34a, the step (G1) is a step of forming a resin film made of a resin composition containing the (A) resin on a substrate etc. The resin film may be formed by applying or laminating a resin composition containing the (A) resin or a resin sheet formed from the resin composition containing the (A) resin.

[0309] The substrate can be a light emitting element driving substrate 7. Figure 34a shows an example of a TFT array substrate in which TFTs 23, insulating films 24, and wiring 4 are arranged on a glass substrate.

[0310] The insulating film 24 is not particularly limited, but examples thereof include a silicon oxide film, a silicon nitride film, and an insulating film made of an organic material.

[0311] Next, in step (G2), as shown in FIG. 34a, a plurality of penetrating opening patterns are formed in the resin film using a photolithography process.

[0312] Next, in step (G3), as shown in FIG. 34a, the resin film is cured to form a cured film 3 having a transmittance of 80% or more and 100% or less for light with a wavelength of 450 nm at a thickness of 5 μm.

[0313] Next, in step (G4), as shown in Fig. 34b, wiring is formed on at least a portion of the surface of the cured film and on a portion of the opening pattern of the cured film. After forming a photoresist layer (not shown), wiring 4e is formed on the surface of a portion of the cured film 3 by, for example, sputtering or processing a photosensitive conductive paste. Thereafter, unnecessary photoresist is removed.

[0314] Examples of wiring 4e include gold, silver, copper, aluminum, nickel, titanium, molybdenum, alloys containing these, compounds containing as a main component an oxide of at least one element selected from the group consisting of indium, gallium, zinc, tin, titanium, and niobium, and photosensitive conductive pastes containing organic matter and conductive particles, but other known materials may also be used.

[0315] Thereafter, wiring 4c is formed as shown in FIG. 34c.

[0316] Next, in step (G5), as shown in Fig. 34d, the light-emitting element 2 is disposed so as to maintain electrical connection with the wiring 4e. The electrode 6 and the wiring 4e may be connected via a bump or a conductive film, or may be connected directly.

[0317] The cured film 3 or the partition wall 16 may be formed before or after arranging the light-emitting elements 2. Then, the cured film 22 is formed, and then the wiring 4d is formed. The wiring 4d may be connected to the wiring 4, 4e extending in the cured film 3 arranged so as to contact at least a part of the light-emitting elements 2 via a through electrode or the like, or may be connected to the light-emitting element driving substrate 7.

[0318] Thereafter, as shown in Fig. 34e, an opposing substrate 5 is attached using an adhesive or the like. Furthermore, a driving element 8 such as a driver IC is electrically connected to the light-emitting element 2 via the wiring 4c and the wirings 4 and 4e extending into the cured film 3, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. Note that the wirings 4d and 4e also include electrodes.

[0319] The driving element 8 may be used singly or in plural for a single light-emitting element 2, for a single unit of light-emitting elements 2 consisting of red, blue, and green light-emitting elements, for multiple light-emitting elements 2, or for multiple units of light-emitting elements 2, depending on the function. For example, one or more driving elements may be disposed near the light-emitting element during the process shown in FIG. 34 . In this case, the driving element is electrically connected to the light-emitting element 2 via the light-emitting element driving substrate 7, wiring 4c, wiring 4 extending into the cured film 3, etc. This ensures electrical insulation of the wiring through the cured film, and extending the wiring through the cured film electrically connects the electrodes of the light-emitting element to the driving element, thereby controlling the light-emitting operation. Furthermore, the cured film has a high optical transmittance at a wavelength of 450 nm at a standard thickness of 5 μm, which suppresses absorption of light emitted from the light-emitting element and improves light extraction.

[0320] The display device of the present invention is suitably used for display devices such as various LED displays and various vehicle-mounted lamps.

[0321] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0322] The display devices in the examples and the cured films made of the resin compositions used in the display devices were evaluated by the following methods.

[0323] <Method for evaluating the transmittance of light with a wavelength of 450 nm when the cured film has a thickness of 5 μm> A varnish made of a resin composition was spin-coated onto a 5 cm square glass substrate so that the film thickness after heat treatment at 230 ° C. for 1 hour was 5.0 μm, and the substrate was pre-baked at 120 ° C. for 3 minutes. Thereafter, using a high-temperature clean oven CLH-21CD-S manufactured by Koyo Thermo Systems Co., Ltd., the temperature was raised from 50 ° C. to 110 ° C. at a rate of 3.5 ° C. / min under a nitrogen stream with an oxygen concentration of 100 ppm or less, and then heat-treated at 110 ° C. for 30 minutes. Thereafter, the temperature was raised at a rate of 3.5 ° C. / min to a heating temperature of 230 ° C., and then heat-treated for 1 hour at the heating temperature after the temperature increase, and the coating film was dried and heat-treated to obtain a cured film. The film thickness of the coating film after pre-baking and after development was measured using an optical interference type film thickness measuring device Lambda Ace STM-602 manufactured by Dainippon Screen Mfg. Co., Ltd., with a refractive index of 1.629, and the film thickness of the cured film was measured with a refractive index of 1.629.

[0324] The transmittance of the cured film thus obtained was measured at a wavelength of 450 nm using a double beam spectrophotometer U-2910 (manufactured by Hitachi High-Tech Science Corp.) In addition, when the film thickness of the heat-resistant resin film after the heat treatment was not 5 μm, the measured transmission spectrum was converted into a film thickness of 5 μm according to Lambert's law.

[0325] <Method for evaluating light extraction efficiency of display device> The light extraction efficiency was measured using the display devices described in the following Examples and Comparative Examples. For the measurement, an external quantum efficiency measurement device C9920 manufactured by Hamamatsu Photonics K.K. The light extraction efficiency was evaluated relative to the light extraction efficiency of the display device in Example 1, which was set to 1.00.

[0326] <Evaluation of opening pattern shape of cured film made of resin composition> A varnish made of the resin composition was prepared and applied to an 8-inch silicon wafer by spin coating using a coating and developing apparatus ACT-8 (manufactured by Tokyo Electron Limited) so that the film thickness after heating would be 5 μm, followed by pre-baking to prepare a pre-baked film. Pre-baking was carried out at 120°C for 3 minutes. Thereafter, an i-line stepper (manufactured by Nikon Corporation, NSR-2205i14) was used to apply 50 to 1000 mJ / cm ２ The exposure was performed with an exposure dose of 1000 u. The size of the circular pattern used for exposure was 5 to 30 μm. After exposure, the film was developed using a 2.38% by mass aqueous solution of tetramethylammonium (TMAH) (manufactured by Tama Chemicals) under conditions such that the change in film thickness in the unexposed areas before and after development was 1.0 to 1.5 μm, followed by rinsing with pure water and shaking off to dry, to obtain a patterned film. Alternatively, the film was developed using cyclopentanone and shaking off to dry, to obtain a patterned film. In the case of a non-photosensitive material, a photoresist was formed before exposure, followed by exposure and development, and then the photoresist was removed after development. The film thickness after pre-baking and development was measured using a Lambda Ace STM-602 optical interference film thickness measuring device manufactured by Dainippon Screen Mfg. Co., Ltd., with a refractive index of 1.629.

[0327] After development, the pattern-forming film was heated in an inert oven CLH-21CD-S (manufactured by Koyo Thermo Systems Co., Ltd.) under a nitrogen stream with an oxygen concentration of 20 ppm or less by raising the temperature from 50°C to 100°C at a rate of 3.5°C / min, and then heat-treated at 100°C for 30 minutes. Thereafter, the temperature was raised to 230°C at a rate of 3.5°C / min, and then heat-treated for 1 hour to harden the pattern-forming film, thereby obtaining a hardened film.

[0328] When the temperature reached 50°C or less, the wafer was removed, and then the wafer was cleaved to observe and measure the cross-sectional shape of the 5 to 30 µm circular pattern using a scanning electron microscope S-4800 (manufactured by Hitachi High-Technologies Corporation). The angle of the slanted side was determined by connecting the opening pattern at a position halfway along the thickness direction of the cured film with the opening pattern at the bottom.

[0329] Synthesis Example 1: Synthesis of Hydroxyl Group-Containing Diamine Compound 18.3 g (0.05 mol) of 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (manufactured by Central Glass Co., Ltd., hereinafter referred to as BAHF) was dissolved in 100 mL of acetone and 17.4 g (0.3 mol) of propylene oxide (manufactured by Tokyo Chemical Industry Co., Ltd.), and the solution was cooled to −15°C. To this solution, a solution prepared by dissolving 20.4 g (0.11 mol) of 3-nitrobenzoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) in 100 mL of acetone was added dropwise. After completion of the dropwise addition, the mixture was stirred at −15°C for 4 hours and then returned to room temperature. The precipitated white solid was filtered and dried in vacuo at 50°C.

[0330] 30 g of the obtained white solid was placed in a 300 mL stainless steel autoclave and dispersed in 250 mL of methyl cellosolve, and 2 g of 5% palladium-carbon (manufactured by Wako Pure Chemical Industries, Ltd.) was added. Hydrogen was introduced into the autoclave using a balloon, and a reduction reaction was carried out at room temperature. After approximately 2 hours, the reaction was terminated when it was confirmed that the balloon no longer deflated. After the reaction was completed, the palladium compound catalyst was removed by filtration, and the mixture was concentrated using a rotary evaporator to obtain a hydroxyl group-containing diamine compound represented by the following formula:

[0331]

[0332] Synthesis Example 2: Synthesis of Polybenzoxazole Precursor (A-1) Under a dry nitrogen stream, 1.5 g (0.0075 mol) of 4,4'-diaminodiphenyl ether (hereinafter referred to as 4,4'-DAE), 12.8 g (0.035 mol) of BAHF, and 5.0 g (0.0050 mol) of RT-1000 (manufactured by HUNTSMAN Corp.) were dissolved in 100 g of NMP. To this solution, dodecanoic acid diimidazole (7.4 g, 0.023 mol) and 1,1'-(4,4'-oxybenzoyl)diimidazole (hereinafter referred to as PBOM) (8.1 g, 0.023 mol) were added along with 25 g of NMP, and the mixture was allowed to react at 85°C for 3 hours. Next, 0.6 g (0.0025 mol) of 1,3-bis(3-aminopropyl)tetramethyldisiloxane (hereinafter referred to as SiDA), 0.8 g (0.0025 mol) of 4,4'-oxydiphthalic anhydride (hereinafter referred to as ODPA), and 0.8 g (0.0050 mol) of 5-norbornene-2,3-dicarboxylic anhydride (hereinafter referred to as NA) were added together with 25 g of NMP, and the mixture was reacted at 85°C for 1 hour. After completion of the reaction, the mixture was cooled to room temperature, and 13.2 g (0.25 mol) of acetic acid was added together with 25 g of NMP, and the mixture was stirred at room temperature for 1 hour. After completion of stirring, the solution was poured into 1.5 L of water to obtain a white precipitate. This precipitate was collected by filtration, washed three times with water, and then dried in a forced-air dryer at 50°C for 3 days to obtain a powder of polybenzoxazole precursor (A-1).

[0333] Synthesis Example 3: Synthesis of Polybenzoxazole Precursor (A-2) Under a dry nitrogen stream, 27.5 g (0.075 mol) of BAHF was dissolved in 257 g of NMP. To this was added 17.2 g (0.048 mol) of PBOM along with 20 g of NMP, and the mixture was allowed to react at 85°C for 3 hours. Subsequently, 20.0 g (0.02 mol) of RT-1000 (HUNTSMAN Corporation), 1.2 g (0.005 mol) of SiDA, and 14.3 g (0.04 mol) of PBOM were added along with 50 g of NMP, and the mixture was allowed to react at 85°C for 1 hour. Furthermore, 3.9 g (0.024 mol) of NA as a terminal blocking agent was added along with 10 g of NMP, and the mixture was allowed to react at 85°C for 30 minutes. After the reaction was completed, the mixture was cooled to room temperature, and 52.8 g (0.50 mol) of acetic acid was added together with 87 g of NMP, followed by stirring at room temperature for 1 hour. After stirring was completed, the solution was poured into 3 L of water to obtain a white precipitate. This precipitate was collected by filtration, washed three times with water, and then dried in a forced air dryer at 50°C for 3 days to obtain a powder of polybenzoxazole precursor (A-2).

[0334] Synthesis Example 4: Synthesis of Polyimide Precursor (A-3) Under a dry nitrogen stream, 51.9 g (0.086 mol) of the hydroxyl group-containing diamine obtained in Synthesis Example 1 and 1.0 g (0.004 mol) of SiDA were dissolved in 200 g of NMP. 31.0 g (0.10 mol) of ODPA was added thereto, and the mixture was stirred at 40°C for 2 hours. 1.1 g (0.01 mol) of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) as an end-capping agent was then added together with 10 g of NMP, and the mixture was allowed to react at 40°C for 1 hour. Subsequently, a solution prepared by diluting 7.1 g (0.06 mol) of dimethylformamide dimethyl acetal (manufactured by Mitsubishi Rayon Co., Ltd., hereinafter referred to as DFA) with 5 g of NMP was added dropwise. After the dropwise addition, stirring was continued for 2 hours at 40°C. After stirring was completed, the solution was poured into 2 L of water, and the polymer solid precipitate was collected by filtration. The mixture was further washed three times with 2 L of water, and the collected polymer solid was dried in a vacuum dryer at 50° C. for 72 hours to obtain a polyimide precursor (A-3).

[0335] Synthesis Example 5: Synthesis of Polyimide Precursor (A-4) Under a dry nitrogen stream, 41.1 g (0.068 mol) of the hydroxyl group-containing diamine obtained in Synthesis Example 1, 18.0 g (0.018 mol) of RT-1000 (manufactured by HUNTSMAN Corporation), and 1.0 g (0.004 mol) of SiDA were dissolved in 200 g of NMP. 31.0 g (0.10 mol) of ODPA was added thereto, and the mixture was stirred at 40°C for 2 hours. 1.1 g (0.01 mol) of 3-aminophenol as an end-capping agent was then added together with 10 g of NMP, and the mixture was allowed to react at 40°C for 1 hour. Thereafter, a solution prepared by diluting 6.0 g (0.05 mol) of DFA with 5 g of NMP was added dropwise. After the dropwise addition, stirring was continued at 40°C for 2 hours. After stirring was completed, the solution was poured into 2 L of water, and the polymer solid precipitate was collected by filtration. The mixture was further washed three times with 2 L of water, and the collected polymer solid was dried in a vacuum dryer at 50° C. for 72 hours to obtain a polyimide precursor (A-4).

[0336] Synthesis Example 6: Synthesis of Polyimide (A-5) Under a dry nitrogen stream, 29.3 g (0.08 mol) of BAHF, 1.2 g (0.005 mol) of SiDA, and 3.3 g (0.03 mol) of 3-aminophenol as an end-capping agent were dissolved in 80 g of NMP. 31.2 g (0.1 mol) of ODPA was added to the solution together with 20 g of NMP, and the mixture was reacted at 60°C for 1 hour, followed by stirring at 180°C for 4 hours. After stirring, the solution was poured into 3 L of water to obtain a white precipitate. The precipitate was collected by filtration, washed three times with water, and then dried in a vacuum dryer at 80°C for 20 hours to obtain a powder of polyimide (A-5).

[0337] Synthesis Example 7: Synthesis of Cardo Resin (A-6) Under a dry nitrogen stream, 198.53 g of a 50% PGMEA solution of an equiequivalent reaction product of bisphenolfluorene epoxy resin and acrylic acid (manufactured by Nippon Steel Chemical Co., Ltd., product name "ASF-400" solution), 39.54 g (0.12 mol) of benzophenonetetracarboxylic dianhydride, 8.13 g (0.08 mol) of succinic anhydride, 48.12 g of PGMEA, and 0.45 g of triphenylphosphine were charged into a four-neck flask equipped with a reflux condenser. The mixture was stirred for 1 hour while heating to 120 to 125°C, and further heated and stirred for 6 hours at 75 to 80°C. Thereafter, 8.6 g of glycidyl methacrylate was added, and the mixture was further stirred at 80°C for 8 hours to obtain a resin (A-6) having a skeletal structure in which two cyclic structures are bonded to a quaternary carbon atom constituting the cyclic structure.

[0338] Synthesis Example 8: Synthesis of Polyimide Precursor (A-7) Under a dry nitrogen stream, 3.2 g (0.03 mol) of 1,4-paraphenylenediamine and 12.0 g (0.06 mol) of 4,4'-DAE were dissolved in 200 g of NMP. 31.0 g (0.10 mol) of ODPA was added thereto, and the mixture was stirred at 40°C for 2 hours. 1.1 g (0.01 mol) of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) as an end-capping agent was then added together with 10 g of NMP, and the mixture was allowed to react at 40°C for 1 hour. Subsequently, a solution prepared by diluting 7.1 g (0.06 mol) of DFA with 5 g of NMP was added dropwise. After the dropwise addition, stirring was continued at 40°C for 2 hours. After stirring was completed, the solution was poured into 2 L of water, and the polymer solid precipitate was collected by filtration. The mixture was further washed three times with 2 L of water, and the collected polymer solid was dried in a vacuum dryer at 50° C. for 72 hours to obtain a polyimide precursor (A-7).

[0339] Synthesis Example 9: Synthesis of Polyimide Precursor (A-8) 155.1 g (0.50 mol) of ODPA was placed in a 2-L separable flask, and 134.0 g (1.00 mol) of 2-hydroxyethyl methacrylate (HEMA) and 400 g of γ-butyrolactone were added. 79.1 g of pyridine was added with stirring at room temperature to obtain a reaction mixture. After the heat generated by the reaction had ceased, the mixture was allowed to cool to room temperature and then allowed to stand for a further 16 hours.

[0340] Next, under ice cooling, a solution of 206.3 g (1.00 mol) of dicyclohexylcarbodiimide (DCC) dissolved in 180 g of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. Subsequently, a suspension of 16.2 g (0.15 mol) of 1,4-paraphenylenediamine and 60.1 g (0.30 mol) of 4,4'-DAE suspended in 350 g of γ-butyrolactone was added over 60 minutes with stirring. After further stirring at room temperature for 2 hours, 30 ml of ethyl alcohol was added and the mixture was stirred for 1 hour. Then, 400 g of γ-butyrolactone was added. The precipitate formed in the reaction mixture was removed by filtration to obtain a reaction solution.

[0341] The reaction solution was poured into 3 L of water to obtain a white precipitate, which was collected by filtration, washed twice with water, washed once with isopropanol, and then dried in a vacuum dryer at 50°C for 72 hours to obtain a polyimide precursor (A-8).

[0342] Synthesis Example 10: Synthesis of Photosensitizer (Quinonediazide Compound (B-1)) Under a dry nitrogen stream, 21.2 g (0.05 mol) of 4,4'-[1-[4-[1-(4-hydroxyphenyl-1)-1-methylethyl]phenyl]ethylidene]bisphenol (manufactured by Honshu Chemical Industry Co., Ltd., hereinafter referred to as TrisP-PA) and 26.8 g (0.10 mol) of 5-naphthoquinonediazide sulfonic acid chloride (manufactured by Toyo Gosei Co., Ltd., NAC-5) were dissolved in 450 g of γ-butyrolactone at room temperature. 12.7 g of triethylamine mixed with 50 g of γ-butyrolactone was added dropwise to the solution so that the temperature in the system did not exceed 35°C. After the dropwise addition, the mixture was stirred at 40°C for 2 hours. The triethylamine salt was filtered off, and the filtrate was poured into water. The precipitate was then collected by filtration and washed with 1 L of 1% aqueous hydrochloric acid, and then washed twice with 2 L of water. The precipitate was dried in a vacuum dryer to obtain a quinone diazide compound (B-1) represented by the following formula:

[0343]

[0344] Synthesis Example 11: Synthesis of Photosensitizer (Quinonediazide Compound (B-2)) Under a dry nitrogen stream, 21.2 g (0.05 mol) of TrisP-PA and 26.8 g (0.10 mol) of 4-naphthoquinonediazide sulfonic acid chloride (NAC-5, manufactured by Toyo Gosei Co., Ltd.) were dissolved in 450 g of γ-butyrolactone at room temperature. 12.7 g of triethylamine mixed with 50 g of γ-butyrolactone was added dropwise thereto so that the temperature in the system did not exceed 35°C. After the dropwise addition, the mixture was stirred at 40°C for 2 hours. The triethylamine salt was filtered, and the filtrate was poured into water. The precipitate was then collected by filtration and washed with 1 L of 1% aqueous hydrochloric acid. The mixture was then washed twice with 2 L of water. The precipitate was dried in a vacuum dryer to obtain quinonediazide compound (B-2) represented by the following formula:

[0345]

[0346] Synthesis Example 12: Synthesis of Polyimide Precursor (A-10) 155.1 g (0.50 mol) of ODPA was placed in a 2-liter separable flask, and 134.0 g (1.00 mol) of 2-hydroxyethyl methacrylate (HEMA) and 400 g of γ-butyrolactone were added. 79.1 g of pyridine was added with stirring at room temperature to obtain a reaction mixture. After the heat generated by the reaction had ceased, the mixture was allowed to cool to room temperature and then allowed to stand for a further 16 hours.

[0347] Next, under ice cooling, a solution of 206.3 g (1.00 mol) of dicyclohexylcarbodiimide (DCC) dissolved in 180 g of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. Subsequently, a suspension of 90.2 g (0.45 mol) of 4,4'-DAE suspended in 350 g of γ-butyrolactone was added over 60 minutes with stirring. After further stirring at room temperature for 2 hours, 30 ml of ethyl alcohol was added and the mixture was stirred for 1 hour. Then, 400 g of γ-butyrolactone was added. The precipitate formed in the reaction mixture was removed by filtration to obtain a reaction solution.

[0348] The reaction solution was poured into 3 L of water to obtain a white precipitate, which was collected by filtration, washed twice with water, washed once with isopropanol, and then dried in a vacuum dryer at 50°C for 72 hours to obtain a polyimide precursor (A-10).

[0349] Synthesis Example 13: Synthesis of acrylic resin (A-11) 33 g of methyl methacrylate, 33 g of styrene, 34 g of methacrylic acid, 3 g of 2,2'-azobis(2-methylbutyronitrile), and 150 g of propylene glycol monomethyl ether acetate (hereinafter, "PGMEA") were charged into a polymerization vessel and stirred at 90°C for 2 hours, after which the liquid temperature was raised to 100°C and the reaction was continued for an additional 1 hour. 33 g of glycidyl methacrylate, 1.2 g of dimethylbenzylamine, and 0.2 g of p-methoxyphenol were added to the resulting reaction solution and stirred at 90°C for 4 hours. At the end of the reaction, 50 g of PGMEA was added to obtain a solution of acrylic resin (A-11) (solids content 40% by mass). The acid value of the acrylic resin (A-11) was 80.0 (mg / KOH / g) and the weight average molecular weight (Mw) was 22,000.

[0350] Synthesis Example 14: Synthesis of Acrylic Resin (A-12) In a reaction vessel under a nitrogen atmosphere, 150 g of dimethylaminomethanol (hereinafter referred to as "DMEA"; manufactured by Tokyo Chemical Industry Co., Ltd.) was charged and heated to 80°C using an oil bath. To this, a mixture consisting of 20 g of ethyl acrylate (hereinafter referred to as "EA"), 40 g of 2-ethylhexyl methacrylate (hereinafter referred to as "2-EHMA"), 20 g of styrene (hereinafter referred to as "St"), 15 g of acrylic acid (hereinafter referred to as "AA"), 0.8 g of 2,2'-azobisisobutyronitrile, and 10 g of DMEA was added dropwise over 1 hour. After completion of the dropwise addition, the polymerization reaction was further carried out at 80°C under a nitrogen atmosphere for 6 hours. Thereafter, 1 g of hydroquinone monomethyl ether was added to terminate the polymerization reaction. Subsequently, a mixture consisting of 5 g of glycidyl methacrylate (hereinafter referred to as "GMA"), 1 g of triethylbenzylammonium chloride, and 10 g of DMEA was added dropwise over 0.5 hours. After completion of the dropwise addition, the addition reaction was further carried out at 80°C under a nitrogen atmosphere for 2 hours. The resulting reaction solution was purified with methanol to remove unreacted impurities, and then vacuum dried for 24 hours to obtain acrylic resin (A-12) having a copolymerization ratio (by mass): EA / 2-EHMA / St / GMA / AA = 20 / 40 / 20 / 5 / 15. The acid value of the resulting acrylic resin (A-12) was 103 mgKOH / g.

[0351] Synthesis Example 15: Synthesis of acrylic resin (A-13) A methyl methacrylate / methacrylic acid / styrene copolymer (mass ratio 30 / 40 / 30) was synthesized by the method described in Example 1 of Japanese Patent No. 3120476. 40 parts by mass of glycidyl methacrylate was added to 100 parts by mass of the obtained copolymer, and the mixture was reprecipitated in purified water, filtered, and dried to obtain acrylic resin (A-13) having a weight average molecular weight of 15,000 and an acid value of 110 mgKOH / g.

[0352] Synthesis Example 16: Synthesis of Siloxane Polymer (A-14) A 1000 ml three-neck flask was charged with 116.07 g (0.475 mol) of diphenyldimethoxysilane, dimethyldimethoxysilane (0.20 mol), 43.46 g (0.175 mol) of 3-methacryloxypropyltrimethoxysilane, 26.23 g (0.10 mol) of 3-trimethoxysilylpropylsuccinic anhydride, 12.32 g (0.05 mol) of 3-(3,4-epoxycyclohexyl)propyltrimethoxysilane, 0.843 g of BHT, and 176.26 g of PGMEA, and an aqueous phosphoric acid solution prepared by dissolving 2.221 g of phosphoric acid (1.0 wt % based on the charged monomers) in 43.65 g of water was added thereto with stirring at room temperature over 30 minutes. Thereafter, a polysiloxane solution was obtained as in Synthesis Example 1. During the reaction, a total of 136.90 g of by-products, methanol and water, were distilled off. PGMEA was added to the resulting polysiloxane solution so that the solids concentration was 40 wt %, yielding a siloxane polymer (A-14) solution. The resulting siloxane polymer (A-14) had a weight-average molecular weight of 2,800. The molar ratios of repeating units derived from diphenyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, and 3-(3,4-epoxycyclohexyl)propyltrimethoxysilane in the siloxane polymer (A-14) were 47.5 mol %, 20 mol %, 17.5 mol %, 10 mol %, and 5 mol %, respectively.

[0353] Preparation Example 1 Preparation of Photosensitive Conductive Paste 1 Into a 100 mL clean bottle were placed 10.0 g of acrylic resin (A-12) as a resin, 0.50 g of "IRGACURE (registered trademark)" OXE-01 (manufactured by Ciba Japan Co., Ltd.) as a photopolymerization initiator, 5.0 g of DMEA as a solvent, and 2.0 g of "Light Acrylate (registered trademark)" BP-4EA (manufactured by Kyoeisha Chemical Co., Ltd.) as a compound having an unsaturated double bond, and mixed using a rotation-revolution vacuum mixer "Awatori Rentaro ARE-310" (manufactured by Thinky Corporation) to obtain 17.5 g of a resin solution (solid content 71.4% by mass).

[0354] 17.50 g of the resulting resin solution was mixed with 44.02 g of silver particles having an average particle size of 1.0 μm and 0.28 g of carbon black having an average particle size of 0.05 μm, and the mixture was kneaded using a three-roller mill "EXAKT M-50" (manufactured by EXAKT) to obtain 61.8 g of photosensitive conductive paste 1. The average particle sizes of the silver particles and carbon black were determined by observing each particle using an electron microscope (SEM) at a magnification of 10,000 times and a field of view width of 12 μm, measuring the maximum width of each of 40 randomly selected primary particles of silver particles and carbon black, and calculating the number average value thereof.

[0355] Preparation Example 2: Production of Colorant Dispersion (DC-1) Zirconia compound particles Zr-1 (manufactured by Nisshin Engineering Inc.) produced by a thermal plasma method were used as the colorant. 200 g of Zr-1, 114 g of a 35 mass % solution of acrylic polymer (P-1) in propylene glycol monomethyl ether acetate (PGMEA), 625 g of "DISPERBYK (registered trademark)" LPN-2111 having a tertiary amino group and a quaternary ammonium salt as a polymer dispersant, and 661 g of PGMEA were charged into a tank and stirred for 20 minutes with a homomixer to obtain a preliminary dispersion. The obtained preliminary dispersion was supplied to an Ultra Apex Mill disperser manufactured by Kotobuki Industries Co., Ltd., equipped with a centrifugal separator filled with 75% by volume of 0.05 mmφ zirconia beads, and dispersion was carried out for 3 hours at a rotation speed of 8 m / s, thereby obtaining a colorant dispersion (DC-1) having a solid content concentration of 25% by mass and a colorant / resin (mass ratio) of 80 / 20.

[0356] Preparation Example 3: Preparation of Photosensitive Colored Resin Composition 1 To 283.1 g of colorant dispersion (DC-1), 184.4 g of a 35 mass % solution of acrylic resin (A-13) in PGMEA, 50.1 g of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional monomer, 7.5 g of "Irgacure (registered trademark)" 907 (manufactured by BASF) as a photopolymerization initiator, and "KAYACURE (registered trademark)" DETX-S (manufactured by Nippon Kayaku Co., Ltd.) were added. 3.8 g of KBM5103 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an adhesion improver, 12.0 g of KBM5103 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an adhesion improver, and a solution obtained by dissolving 3 g of a 10 mass % solution of silicone surfactant "BYK (registered trademark)" 333 (manufactured by BYK-Chemie Co., Ltd.) in 456.1 g of PGMEA as a surfactant was added, and a photosensitive colored resin composition 1 having a total solid content concentration of 20 mass % and a colorant / resin (mass ratio) = 30 / 70 was obtained.

[0357] Preparation Example 4: Production of Colorant Dispersion Liquid (DC-2) Carbon black (CB-Bk1) whose surface was modified with sulfonic acid groups by the method described in JP-A No. 2008-517330 had a surface elemental composition of (C: 88%, O: 7%, Na: 3%, S: 2%), and in terms of the state of the S element, of the S2p peak components, components attributed to C-S and S-S accounted for 90%, and components attributed to SO and SOx accounted for 10%, and the BET value was 54 m / g.

[0358] This carbon black CB-Bk1 (200 g), acrylic resin (A-13) propylene glycol monomethyl ether acetate 40% by weight solution (94 g), polymer dispersant BYK Japan LPN21116, 40% by weight solution (31 g) and propylene glycol monomethyl ether acetate (675 g) were charged into a tank, and stirred with a homomixer (manufactured by Tokushu Kika) for 1 hour to obtain a preliminary dispersion. Then, 0.05 mmφ zirconia beads (Nikkato YTZ balls) were supplied to an Ultra Apex Mill (manufactured by Kotobuki Industries) equipped with a centrifugal separator filled 70%, and the preliminary dispersion was dispersed for 2 hours at a rotation speed of 8 m / s to obtain a colored dispersion DC-2 of 25% by weight, pigment / resin (mass ratio) = 80 / 20.

[0359] <Preparation Example 5 Preparation of photosensitive colored resin composition 2> To 534.8 g of colorant dispersion (DC-2), 122.1 g of a 40 mass% solution of acrylic resin (A-13) in PGMEA, 47.3 g of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional monomer, 11.8 g of "ADEKA CRUISE" NCI-831 (manufactured by ADEKA Corporation) as a photopolymerization initiator, 12.0 g of KBM5103 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an adhesion improver, and 4 g of a 10 mass% solution of silicone surfactant "BYK (registered trademark)" 333 (manufactured by BYK-Chemie Co., Ltd.) as a surfactant were dissolved in 194.0 g of PGMEA to obtain a photosensitive colored resin composition 2, with a total solids concentration of 25 mass%, colorant / resin (mass ratio) = 45 / 55.

[0360] The components (A-9), (B-3), (C-1), (C-2), other components, and solvents used in the examples and comparative examples are as follows: (A-9) Phenolic resin MEHC-7851 (manufactured by Meiwa Chemical Industry Co., Ltd.) (C-1) HMOM-TPHAP (manufactured by Honshu Chemical Industry Co., Ltd.) (C-2) YX4000H (manufactured by Mitsubishi Chemical Corporation)

[0361]

[0362] (B-3): Photopolymerization initiator NCI-831 (manufactured by ADEKA Corporation) (B-4): Photopolymerization initiator OXE-02 (manufactured by BASF Japan Ltd.) (B-5): Photopolymerization initiator IC-819 (manufactured by BASF Japan Ltd.) Other components: (F-1): Dipentaerythritol hexaacrylate (DPHA, manufactured by Kyoeisha Chemical Co., Ltd.) (F-2): 2,4-diethylthioxanthone (KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.) (F-3): 2,5-bis(1,1,3,3-tetramethylbutyl)hydroquinone (DOHQ, manufactured by Wako Pure Chemical Industries, Ltd.) Solvent: GBL: gamma-butyrolactone PGMEA: propylene glycol monomethyl ether acetate.

[0363] Table 1 shows the formulation of a resin composition composed of (A) resin, (B) photosensitizer, and (C) thermal crosslinker. Resin composition 1-19 was prepared using the solvent shown in Table 1 so that the solids concentration was 40% by mass. Tables 2-1 and 2-2 show the resin compositions used in the examples, the light transmittance (%) of the cured film of the resin composition at a wavelength of 450 nm and a standard thickness of 5 μm, the total thickness (μm) of the cured film, the number of layers of the cured film, the shape and length of the opening pattern processed into the cured film, the presence or absence of step (D6) or step (E8), the light extraction efficiency from the display device, and the angle of the inclined side of the opening pattern.

[0364]

[0365]

[0366]

[0367] Regarding the evaluation level (1), the display device was classified as Level A when the light extraction efficiency of the display device was 1.10 or more compared to Example 1 and the longest length of the opening pattern was 5 μm or less; Level B when the light extraction efficiency of the display device was 1.00 or more compared to Example 1 and the longest length of the opening pattern was 5 μm or less; Level C when the light extraction efficiency of the display device was 1.00 or more compared to Example 1 and the longest length of the opening pattern was more than 5 μm and 20 μm or less; Level D when the light extraction efficiency of the display device was 1.00 or more compared to Example 1 and the longest length of the opening pattern was greater than 20 μm; and Level E when the light extraction efficiency of the display device was less than 1.00 compared to Example 1.

[0368] Regarding the evaluation level (2), the angle of the inclined side was evaluated as level A when it was 55° or more and 80° or less, level B when it was 40° or more and less than 55° or more than 80° and 85° or less, and level C when it was less than 40° or more than 85°.

[0369] (Example 1) (Configuration of Figure 11) An example of a display device of the present invention will be described with reference to the cross-sectional view of Figure 11 taken along a plane perpendicular to the support substrate or counter substrate, showing the fabrication process. As shown in Figure 11a, a glass substrate was used as the support substrate 20. A temporary bonding material made of polyimide was placed on the glass substrate, and ITO was formed as wiring 4d on a portion of the surface of the temporary bonding material by sputtering. Then, a light-emitting element 2, which is a light-emitting element, was placed on the support substrate 20 (corresponding to step (D1)). The light-emitting element 2 had a thickness of 7 μm, one side length of 30 μm, and the other side length of 50 μm.

[0370] Next, as shown in Figure 11b, resin composition 1 described in Table 1 was applied onto the support substrate 20 and the light-emitting element 2 so that the thickness would be 10 μm after heat treatment, thereby forming a resin film 21 (corresponding to process (D2)).

[0371] Next, as shown in Fig. 11c, the resin film 21 was irradiated with i-line (365 nm) light through a mask having a desired pattern. The exposed resin film 21 was developed using a 2.38 mass % tetramethylammonium (TMAH) aqueous solution to form a plurality of opening patterns 12 penetrating the resin film 21 in the thickness direction (corresponding to step (D3)). The opening patterns were circular, and the longest length of the bottom surface of the smallest region of the opening pattern was 2 µm in diameter.

[0372] Next, the resin film 21 was heat-treated at 110° C. for 30 minutes in an atmosphere with an oxygen concentration of 100 ppm or less, and then further heat-treated at 230° C. for 60 minutes to be cured, thereby forming a cured film 3 having a thickness of 10 μm (corresponding to step (D4)).

[0373] Next, as shown in Fig. 11d, a titanium barrier metal was sputtered onto the cured film 3, and a copper seed layer was further formed thereon by sputtering. After that, a photoresist layer was formed, and then copper wiring 4 electrically connected to the light-emitting element 2 was formed on the opening pattern 12 of the cured film 3 and on a portion of the surface of the cured film 3 by plating. Then, the photoresist, seed layer, and barrier metal were removed (corresponding to step (D5)). The thickness of the wiring 4a formed on the portion of the surface of the cured film 3 was 5 µm.

[0374] Then, as shown in Figures 11e-f, steps (D2), (D3), (D4), and (D5) were repeated twice to form three layers of cured film 3. As a result, the total thickness of the three layers of cured film 3 was 30 μm. Then, as shown in Figure 11g, a barrier metal 9 was formed by sputtering in the opening pattern 12 of cured film 3, forming bumps 10. Then, as shown in Figure 11h, the bumps were reflowed at 250°C for 1 minute, and electrically connected to a light-emitting element drive substrate 7 having a driver IC (drive element 8) via the bumps 10. The support substrate 20 was then peeled off, and the opposing substrate 5 was attached using an adhesive or the like to obtain a display device 1 having multiple light-emitting elements 2. Note that a glass substrate with copper wiring was used as the light-emitting element drive substrate 7, and wiring 4c was used on its side as shown in Figure 11h. The photosensitive conductive paste 1 of Preparation Example 1 was used as wiring 4c (corresponding to step D9). The wiring 4c was prepared as follows.

[0375] <Preparation of wiring 4c using photosensitive conductive paste 1 of Preparation Example 1> Photosensitive conductive paste 1 was applied to a release PET film having a thickness of 16 μm and a release agent applied thereto, so that the film thickness after drying would be 6.0 μm, and the resulting coating film was dried for 10 minutes in a drying oven at 100° C. Thereafter, an exposure device having an ultra-high pressure mercury lamp was used to expose the wiring 4c to 350 mJ / cm. ２ After exposure at an exposure dose of 1000 ppm, the film was spray-developed using a 0.1% by mass aqueous sodium carbonate solution as a developer at a pressure of 0.1 MPa for 30 seconds to obtain a pattern. The resulting pattern was then cured in a drying oven at 140°C for 30 minutes to obtain a transfer sample with wiring. The resulting pattern had a line width of 50 μm and a line length of 90 mm. The transfer sample was bonded to both sides so that a portion of the wiring was located at the edge of the glass having the R-chamfered portion, and the side surface of the glass was pressed against a hot plate at 130°C for 30 seconds. The remaining portion was then transferred using a hot roll laminator at 130°C and 1.0 m / min.

[0376] Example 2 A display device 2 was obtained in the same manner as in Example 1, except that the resin composition 1 in Example 1 was changed to a resin sheet made of resin composition 2, and the resin film 21 was formed by lamination.

[0377] Examples 3 to 11 Display devices 3 to 11 were obtained in the same manner as in Example 1, except that resin composition 1 in Example 1 was changed to resin compositions 3 to 11.

[0378] (Example 12) A display device 12 was obtained in the same manner as in Example 1, except that the resin composition 1 in Example 1 was changed to resin composition 12, a photoresist was formed before exposure, and the photoresist was removed after development.

[0379] Example 13 Example 13 was carried out in the same manner as Example 2, except that, in Example 2, a step (D6) was added after step (D3) and before step (D4), in which i-line (365 nm) was irradiated onto the entire area of ​​the resin film 21 on which the opening pattern 12 obtained in step (D3) was patterned, to obtain a display device 13.

[0380] Example 14 As shown in Fig. 12a, partition walls 16 were formed on a support substrate 20 (corresponding to step D7). Next, as shown in Fig. 12b, light-emitting elements 2 were formed between the partition walls 16 (corresponding to step (D1)). Except for this, a display device 14 was manufactured using the same steps as in Example 3. The light-emitting elements 2 had a thickness of 7 µm, and the partition walls 16 were formed to a thickness of 10 µm. The partition walls 16 were made of a known acrylic resin containing a white pigment.

[0381] 11c, aluminum was formed to a thickness of 0.2 μm by sputtering at predetermined positions so as to avoid the wiring 4 to be formed later (step (D8)), as shown in FIG. 13d, in the same manner as in Example 3, to provide a reflective film 15. Except for this, a display device 15 was manufactured using the same steps as in Example 3.

[0382] Example 16 An example of a display device of the present invention will be described with reference to the cross-sectional view of a plane perpendicular to the support substrate or counter substrate, which shows an example of the manufacturing process in Figure 14. First, as shown in Figure 14a, a copper pad 18 was placed on the support substrate 20 (corresponding to step (E1)). The pad had a thickness of 0.2 μm.

[0383] Next, as shown in FIG. 14b, resin composition 1 described in Table 1 was applied onto the support substrate 20 and the pads 18 so as to have a thickness of 10 μm after heat treatment, thereby forming a resin film 21 (corresponding to step (E2)).

[0384] Next, as shown in FIG. 14c, a plurality of opening patterns 12 were formed in the resin film 21 under the same conditions as in the photolithography process shown in Example 1 (corresponding to process (E3)).

[0385] Next, the resin film 21 was cured under the same conditions as in Example 1 to form a cured film 3 having a thickness of 10 μm (corresponding to step (E4)).

[0386] Next, in FIG. 14c, in order to improve the adhesion between the cured film 3 and the wiring 4, a barrier metal such as titanium was sputtered on the cured film 3, and a copper seed (seed layer) was further formed on top of that by sputtering.

[0387] 14d, after forming a photoresist layer, wiring 4 made of copper was formed by plating on the opening pattern 12 of the cured film 3 and on a portion of the surface of the cured film 3 (corresponding to step (E5)). The thickness of the wiring 4a formed on the portion of the surface of the cured film 3 was 5 μm. Thereafter, the photoresist, seed layer, and barrier metal were removed.

[0388] Thereafter, steps (E2), (E3), (E4), and (E5) were repeated twice to form three layers of cured films 3 having wiring 4 therein, as shown in Fig. 14e. As a result, the total thickness of the three layers of cured films 3 was 30 µm.

[0389] 14f, the light-emitting element 2 was placed on the cured film 3 so as to maintain electrical connection with the wiring 4 (corresponding to step (E6)). The thickness of the light-emitting element 2 was 7 μm.

[0390] Next, as shown in FIG. 14g, a resin film 21 made of resin composition 1 was formed on the cured film 3 and the light-emitting element 2, and then cured by heat treatment to form a cured film 22. The resin film 21 was then heat-treated at 110°C for 30 minutes in an atmosphere with an oxygen concentration of 100 ppm or less, followed by a further heat treatment at 230°C for 60 minutes to form the cured film 22. ITO was then formed as wiring 4d on a portion of the surface of the cured film 22 by sputtering. Next, as shown in FIG. 14h, the support substrate 20 was peeled off, and a light-emitting element drive substrate 7 having a driver IC (drive element 8) was electrically connected via bumps 10. Furthermore, a counter substrate 5 was attached to the light-emitting element 2 using an adhesive or the like to obtain a display device 16 having a plurality of light-emitting elements 2. The light-emitting element drive substrate 7 was a glass substrate with copper wiring, and wiring 4c was used on its side as shown in FIG. 14h. The photosensitive conductive paste 1 of Preparation Example 1 was used as wiring 4c.

[0391] Example 17 A display device 17 was obtained in the same manner as in Example 16, except that the resin composition 1 in Example 16 was changed to the resin composition 2.

[0392] (Example 18) The same procedure as in Example 16 was carried out, except that the resin composition 1 in Example 16 was changed to resin composition 3, and the support substrate 20 was used as the light-emitting element driving substrate 7 on which the wiring 4c was formed, and was used as is without undergoing a peeling process, to obtain a display device 18.

[0393] (Example 19) In Example 17, a display device 19 was obtained in the same manner as in Example 17, except that a step (E8) of irradiating i-line (365 nm) onto the entire area of ​​the resin film 21 on which the opening pattern 12 obtained in step (E3) was patterned was added after step (E3) and before step (E4).

[0394] (Example 20) After forming multiple layers of the cured film 3 shown in Figure 14e in the same manner as in Example 18, partition walls 16 were formed between and around the light-emitting elements 2 to be arranged later using the resin composition 3 as shown in Figure 15f (corresponding to step (E9)), and then multiple light-emitting elements 2 were arranged as shown in Figure 15g, and as shown in Figure 15h, the support substrate 20 was peeled off and a light-emitting element drive substrate 7 having a driver IC, which is a drive element 8, was electrically connected via bumps 10, and an opposing substrate 5 was attached to the light-emitting elements 2 using an adhesive or the like, thereby obtaining a display device 20 having multiple light-emitting elements 2. The thickness of the light-emitting elements 2 was 7 µm, and the thickness of the partition walls was 10 µm.

[0395] (Example 21) After the step (E5) of forming the hardened film shown in Fig. 14e in the same manner as in Example 18, aluminum was formed to a thickness of 0.5 µm by sputtering at predetermined positions so as to avoid the formed wiring 4, and a reflective film 15 was provided as shown in Fig. 16f (corresponding to step (E10)). Thereafter, a display device 21 was manufactured in the same manner as in Example 18.

[0396] (Example 22) The same procedure as in Example 1 was carried out except that the resin composition 1 in Example 1 was changed to the resin composition 17 and the exposed resin film 21 was developed using cyclopentanone, to obtain a display device 22.

[0397] (Example 23) The same procedure as in Example 16 was carried out except that the resin composition 1 in Example 16 was changed to the resin composition 17 and the exposed resin film 21 was developed using cyclopentanone, to obtain a display device 23.

[0398] (Example 24) Resin composition 1 in Example 16 was changed to resin composition 18, and as shown in Figure 14b, resin composition 18 listed in Table 1 was applied to a support substrate 20 and a pad 18 so that the thickness after heat treatment would be 3 μm, forming a resin film 21 (corresponding to step (E2)). Next, as shown in Figure 14c, a plurality of opening patterns 12 were formed in resin film 21 under the same conditions as in the photolithography process shown in Example 1, except that the developer was changed to a 0.4 mass% tetramethylammonium (TMAH) aqueous solution (corresponding to step (E3)).

[0399] Next, the resin film 21 was cured under the same conditions as in Example 1 to form a cured film 3 having a thickness of 3 μm (corresponding to step (E4)).

[0400] Next, in FIG. 14c, in order to improve the adhesion between the cured film 3 and the wiring 4, a barrier metal such as titanium was sputtered on the cured film 3, and a copper seed (seed layer) was further formed on top of that by sputtering.

[0401] 14d, a photoresist layer was formed, and then copper wiring 4 was formed by plating on the opening pattern 12 of the cured film 3 and on a portion of the surface of the cured film 3 (corresponding to step (E5)). The thickness of the wiring 4a formed on the portion of the surface of the cured film 3 was 1.5 μm. Thereafter, the photoresist, seed layer, and barrier metal were removed.

[0402] Thereafter, steps (E2), (E3), (E4), and (E5) were repeated twice to form three layers of cured films 3 having wiring 4 therein, as shown in Fig. 14e. As a result, the total thickness of the three layers of cured films 3 was 9 µm.

[0403] 14f, the light-emitting element 2 was placed on the cured film 3 so as to maintain electrical connection with the wiring 4 (corresponding to step (E6)). The thickness of the light-emitting element 2 was 7 μm.

[0404] Next, as shown in Fig. 14g, a resin film 21 made of the resin composition 18 was formed on the cured film 3 and the light-emitting element 2, and cured by heat treatment to form a cured film 22. After heat treatment at 110°C for 30 minutes in an atmosphere with an oxygen concentration of 100 ppm or less, further heat treatment was performed at 230°C for 60 minutes to form the cured film 22. Thereafter, ITO was formed as wiring 4d on a portion of the surface of the cured film 22 by sputtering.

[0405] Next, as shown in Fig. 14h, the support substrate 20 was peeled off, and a light-emitting element drive substrate 7 having a driver IC, which is a drive element 8, was electrically connected via bumps 10. Furthermore, an opposing substrate 5 was attached to the light-emitting elements 2 using an adhesive or the like, thereby obtaining a display device 24 having a plurality of light-emitting elements 2. Note that a glass substrate having copper wiring was used as the light-emitting element drive substrate 7, and wiring 4c was used on its side as shown in Fig. 14h, and the photosensitive conductive paste 1 of Preparation Example 1 was used as the wiring 4c.

[0406] (Example 25) Resin composition 1 in Example 1 was changed to resin composition 3, and a TFT substrate was used as the light-emitting element driving substrate 7 as shown in Fig. 11h, and grooves were formed on the side surface of the TFT substrate by laser processing, and titanium and copper were formed in that order by sputtering, and then copper was formed by plating to form wiring 4c (corresponding to process D9). Except for this, the same method as in Example 1 was used to obtain a display device 25.

[0407] (Example 26) Resin composition 1 in Example 16 was changed to resin composition 3, and a TFT substrate was used as the light-emitting element driving substrate 7 as shown in Fig. 14h, and grooves were formed on the side surface by laser processing, and titanium and copper were formed in that order by sputtering, and then copper was formed by plating to form wiring 4c (corresponding to step E11). Except for this, the same method as in Example 16 was used to obtain a display device 26.

[0408] Example 27 Wiring 4c was used on the side surface of light-emitting element drive substrate 7 of Example 25 as shown in Figure 11h, and photosensitive conductive paste 1 of Preparation Example 1 was used as wiring 4c (corresponding to step D9). Except for this, the same method as in Example 25 was carried out to obtain display device 27.

[0409] (Example 28) On the side surface of the light-emitting element drive substrate 7 of Example 26, wiring 4c was used as shown in Figure 14h, and the photosensitive conductive paste 1 described in Example 27 was used as the wiring 4c (corresponding to step E11). Except for this, the same method as in Example 26 was carried out to obtain a display device 28.

[0410] (Example 29) A printed wiring board was used as the light-emitting element driving substrate 7 of Example 25, and the same procedure as Example 25 was carried out except that wiring 4c was not formed and the driving element 8 and wiring 4 were connected through wiring and bumps in the printed wiring board, to obtain a display device 29.

[0411] (Example 30) A printed wiring board was used as the light-emitting element driving substrate 7 of Example 26, and the display device 30 was obtained in the same manner as Example 26, except that wiring 4c was not formed and the driving element 8 and wiring 4 were connected through wiring and bumps in the printed wiring board.

[0412] Example 31 As shown in Fig. 23a, a light-shielding layer 26 was formed on a support substrate 20 (corresponding to step D10). Next, as shown in Fig. 23a, a light-emitting element 2 was formed between the light-shielding layers 26 (corresponding to step (D1)). Except for this, a display device 31 was manufactured using the same steps as in Example 3. The light-shielding layer 26 was manufactured as follows.

[0413] <Preparation of Light-Shielding Layer 26> The colored resin composition 1 was applied to the support substrate 20 so as to have a thickness of 1 μm after heat treatment, and the applied film was heated and dried for 2 minutes on a hot plate at 100° C. This dried film was exposed to ultraviolet light at 200 mJ / cm using an exposure device having an ultra-high pressure mercury lamp. ２ The film was then developed using an alkaline developer of a 0.045% by mass aqueous solution of potassium hydroxide, followed by rinsing with pure water to obtain a patterned film. The obtained patterned film was post-baked in a hot air oven at 230°C for 30 minutes to obtain a light-shielding layer.

[0414] Example 32 A display device 32 was produced in the same manner as in Example 31, except that the light-shielding layer 26 in Example 31 was changed to the colored resin composition 2 to form the light-shielding layer 26 .

[0415] (Example 33) In Figure 11f, a display device 33 was obtained by the same process as in Example 3, except that the thickness of the wiring 4a in contact with the bump 10 was 10 µm, the thickness of the cured film 3 formed on a part of the surface of the wiring 4a was 15 µm, and the total thickness of the cured film 3 was 35 µm.

[0416] (Example 34) In Figure 14b, a display device 34 was obtained by the same process as in Example 18, except that the thickness of the pad 18 was 10 µm, the thickness of the cured film 3 formed on a part of the surface of the pad was 15 µm, and the total thickness of the cured film 3 was 35 µm.

[0417] Example 35 A display device according to Example 35 of the present invention will be described with reference to the cross-sectional view of a plane perpendicular to the light-emitting element drive substrate shown in Figure 24, which illustrates an example of the manufacturing process. As shown in Figure 24a, a TFT array substrate was used as the light-emitting element drive substrate 7, and the resin composition 3 shown in Table 1 was applied to the light-emitting element drive substrate 7 so that the thickness would be 3 μm after heat treatment, forming a resin film 21 (corresponding to step (F1)). The wiring 4 had a thickness of 1 μm. Next, a plurality of opening patterns 12 were formed in the resin film 21 under the same conditions as the photolithography process shown in Example 3 (corresponding to step (F2)).

[0418] Next, the resin film 21 was cured under the same conditions as in Example 3 to form a cured film 3 having a thickness of 3 μm (corresponding to step (F3)).

[0419] Next, as shown in Figure 24b, the wiring was formed on at least a portion of the surface of the cured film and on a portion of the opening pattern of the cured film. After forming a photoresist layer (not shown), ITO was formed as wiring 4e on a portion of the surface of the cured film 3 by sputtering. Then, unnecessary photoresist was removed (corresponding to step (F4)). The thickness of the ITO was 0.1 µm.

[0420] 24c, steps (F1), (F2), and (F3) were repeated to cure the resin composition 3 described in Table 1, thereby forming a cured film 3 having a thickness of 2 μm. Thereafter, wiring 4c was formed using the photosensitive conductive paste 1 of Preparation Example 1.

[0421] Next, as shown in FIG. 24d, partition walls 16 were formed on the cured film 3. Next, light-emitting elements 2 were formed between the partition walls 16 (step (corresponding to F5)). The light-emitting elements 2 were formed to a thickness of 7 μm, and the partition walls 16 were formed to a thickness of 8 μm. The partition walls 16 were made of a known acrylic resin containing a white pigment. A resin film 21 made of a resin composition 18 was formed on the cured film 3 and the light-emitting elements 2, and cured by heat treatment to form a cured film 22. ITO was formed as wiring 4d on part of the surface of the cured film 3 by sputtering.

[0422] 24e, an opposing substrate 5 was attached using an adhesive. In addition, a driving element 8 such as a driver IC was electrically connected to the light-emitting element 2 via the wiring 4c and the wiring 4 and wiring 4e extending into the cured film 3, thereby obtaining a display device 35 having a plurality of light-emitting elements 2.

[0423] (Example 36) A display device 36 was obtained in the same manner as in Example 3, except that a light-emitting element 2 having electrodes on each of its discontinuous surfaces as shown in Figure 27 was used, a temporary bonding material made of polyimide was placed on a glass substrate, and the light-emitting element 2, which is a light-emitting element, was placed on the support substrate 20 on which the temporary bonding material was placed (corresponding to process (D1)).

[0424] Example 37 A display device 37 was obtained in the same manner as in Example 18, except that a light-emitting element 2 having electrodes on each of its discontinuous surfaces as shown in FIG. 28 was used.

[0425] Example 38 A display device 38 was obtained in the same manner as in Example 35, except that a light-emitting element 2 having electrodes on each of its discontinuous surfaces as shown in FIG. 29 was used.

[0426] Example 39 A display device 39 was obtained in the same manner as in Example 3, except that the number of layers of the cured film 3 was one and the total thickness was 10 μm.

[0427] Example 40 A display device 40 was obtained in the same manner as in Example 18, except that the number of layers of the cured film 3 was one and the total thickness was 5 μm.

[0428] Example 41 A display device 41 was obtained in the same manner as in Example 3, except that the number of layers of the cured film 3 was 5 and the total thickness was 50 μm.

[0429] Example 42 A display device 42 was obtained in the same manner as in Example 3, except that the number of layers of the cured film 3 was 10 and the total thickness was 50 μm.

[0430] Example 43 A display device 43 was obtained in the same manner as in Example 3, except that the number of layers of the cured film 3 was 11 and the total thickness was 110 μm.

[0431] Example 44 A display device according to Example 44 of the present invention will be described with reference to the cross-sectional view of a plane perpendicular to the light-emitting element driving substrate shown in Figure 34, which illustrates an example of the manufacturing process. As shown in Figure 34a, a TFT array substrate was used as the light-emitting element driving substrate 7, and the resin composition 3 shown in Table 1 was applied to the light-emitting element driving substrate 7 so that the thickness would be 3 μm after heat treatment, forming a resin film 21 (corresponding to step (G1)). The thickness of the wiring 4 was 1 μm. Next, a plurality of opening patterns 12 were formed in the resin film 21 under the same conditions as the photolithography process shown in Example 3 (corresponding to step (G2)).

[0432] Next, the resin film 21 was cured under the same conditions as in Example 3 to form a cured film 3 having a thickness of 3 μm (corresponding to step (G3)).

[0433] Next, as shown in Figure 34b, the wiring was formed on at least a portion of the surface of the cured film and on a portion of the opening pattern of the cured film. After forming a photoresist layer (not shown), ITO was formed as wiring 4e on a portion of the surface of the cured film 3 by sputtering. Then, unnecessary photoresist was removed (corresponding to step (G4)). The thickness of the ITO was 0.1 µm.

[0434] Next, as shown in FIG. 34c, the photosensitive conductive paste 1 of Preparation Example 1 was used to form the wiring 4c.

[0435] Next, as shown in FIG. 34d, partition walls 16 were formed on the cured film 3. Next, light-emitting elements 2 were formed between the partition walls 16 (step (corresponding to G5)). The light-emitting elements 2 were formed to a thickness of 7 μm, and the partition walls 16 were formed to a thickness of 8 μm. The partition walls 16 were made of a known acrylic resin containing a white pigment. A resin film 21 made of a resin composition 18 was formed on the cured film 3 and the light-emitting elements 2, and cured by heat treatment to form a cured film 22. ITO was formed as wiring 4d on part of the surface of the cured film 3 by sputtering.

[0436] Thereafter, as shown in Fig. 34e, an opposing substrate 5 was attached using an adhesive. In addition, a driving element 8 such as a driver IC was electrically connected to the light-emitting element 2 via the wiring 4c and the wiring 4 and wiring 4e extending into the cured film 3, thereby obtaining a display device 48 having a plurality of light-emitting elements 2.

[0437] (Example 45) Display device 49 was obtained by the same method as in Example 44, except that light-emitting element 2 having electrodes on each of the discontinuous surfaces as shown in FIG. 33 was used. (Example 46) Display device 50 was obtained by the same method as in Example 1, except that resin composition 1 in Example 1 was changed to resin composition 19. (Example 47) Display device 51 was obtained by the same method as in Example 16, except that resin composition 1 in Example 16 was changed to resin composition 19. (Example 48) Display device 52 was obtained by the same method as in Example 35, except that resin composition 3 in Example 35 was changed to resin composition 19. (Example 49) Display device 53 was obtained by the same method as in Example 44, except that resin composition 3 in Example 44 was changed to resin composition 19.

[0438] As a result, the display devices 1 to 43 and 48 to 53 had high light transmittance at a wavelength of 450 nm when the cured film 3 had a standard thickness of 5 μm, resulting in improved light extraction efficiency and brightness. Furthermore, compared to conventional structures, it was possible to reduce wiring defects such as wiring shorts due to a low package height and short wiring distance, reduce loss, and improve high-speed response. Furthermore, the display devices 1 to 11 and 13 to 43 were capable of microfabrication, allowing for the use of minute light-emitting elements and high-density packaging of light-emitting elements. Furthermore, a cured film made of a resin composition could also be used as the partition wall 16, and forming the partition wall facilitated bonding of the opposing substrate. Furthermore, in the display devices 1 to 28, 31 to 43, and 50 to 53, at least a portion of the wiring 4c extended to the side of the substrate, thereby improving the low profile and high-speed response of the display device itself and further enabling the display device to be made smaller and have a narrower frame. Furthermore, by forming a light-shielding layer between multiple light-emitting elements in display devices 31 and 32, it was possible to suppress light leakage from the light-emitting elements and color mixing between pixels, thereby improving contrast, without significantly impairing light extraction efficiency. In display devices 33 and 34, the thickness of the wiring near the bumps 10 was thicker than the thickness of the wiring near the light-emitting elements 2, which prevented wiring defects when connecting the light-emitting element drive substrate 7 using the bumps 10, resulting in highly reliable display devices. In display devices 39, 40, 48, 49, and 53, the number of light-emitting elements that could be arranged was limited because the cured film 3 had a single layer. In display device 43, the overall thickness of the cured film exceeded 100 μm, reducing the step flatness, which caused issues when mounting the light-emitting elements.

[0439] Comparative Examples 1, 3 to 4 Display devices 44, 46 to 47 were obtained in the same manner as in Example 1, except that resin composition 1 in Example 1 was changed to resin compositions 13, 15 to 16.

[0440] Comparative Example 2 The same procedure as in Example 1 was carried out except that the resin composition 1 in Example 1 was changed to the resin composition 14 and the exposed resin film 21 was developed using cyclopentanone, to obtain a display device 45.

[0441] As a result, in the display devices 44 to 47, the light transmittance at a wavelength of 450 nm when the cured film 3 had a standard thickness of 5 μm was low, and therefore the light extraction efficiency and brightness were not achieved.

[0442] REFERENCE SIGNS LIST 1 Display device 2 Light-emitting element 3 Cured film 4, 4c, 4d, 4e Wiring 4a Thickness of wiring arranged on the surface of the cured film 4b Thickness of wiring extending in an opening pattern penetrating the cured film in the thickness direction 5 Counter substrate 6 Electrode 7 Light-emitting element driving substrate 8 Driving element 9 Barrier metal 10 Bump 11a Designated area A 11b Designated area B 12 Opening pattern 13 Bottom portion of wiring 4 14 Longest length of bottom portion 15 Reflective film 16 Partition wall 17 External substrate 18 Pad 19 Overall thickness of cured film 20 Support substrate 21 Resin film 22 Cured film 23 TFT 24 TFT insulating layer 25 Contact hole 26 Light-shielding layer 27 Inclined side 28 Angle of inclined side 29 Thickness of cured film 3 30 Position at 1 / 2 the thickness of effect film 3

Claims

1. A display device having at least wiring, a cured film, and a plurality of light-emitting elements, wherein each light-emitting element has electrodes on two different surfaces, at least one of the electrodes is connected to a plurality of wirings extending in the cured film, the plurality of wirings are configured to maintain electrical insulation by the cured film, the cured film is a film obtained by curing a resin composition containing (A) resin, the transmittance of light at a wavelength of 450 nm at a thickness of 5 μm of the cured film is 80% or more and 100% or less, and the resin composition containing (A) resin further contains (B) a photosensitive agent.

2. The display device according to claim 1, wherein the total thickness of the cured film is 5 μm or more and 100 μm or less.

3. The display device according to claim 1 or 2, wherein the number of layers of the cured film is two or more and ten or less.

4. The display device according to claim 1 or 2, wherein the cured film is provided with an opening pattern that penetrates in the thickness direction, and the wiring is arranged in at least the opening pattern, and the longest length of the bottom surface portion of the wiring formed in contact with the light-emitting element is 2 μm or more and 20 μm or less.

5. The display device according to claim 1 or 2, wherein the cured film covers a surface other than the light extraction surface of the light-emitting element.

6. A display device comprising at least a substrate having wiring and / or TFTs, a cured film, and a plurality of light-emitting elements, wherein each light-emitting element has electrodes on two different surfaces, at least a portion of the wiring and / or TFTs is in contact with the cured film, the cured film is a film obtained by curing a resin composition containing (A) resin, the transmittance of light at a wavelength of 450 nm at a thickness of 5 μm of the cured film is 80% or more and 100% or less, and the resin composition containing (A) resin further contains (B) a photosensitive agent.

7. The display device according to claim 1 or 6, wherein a reflective film is further provided on the cured film.

8. The display device according to claim 1 or 6, wherein a partition wall having a thickness greater than or equal to the thickness of the light-emitting element is provided between a plurality of the light-emitting elements.

9. The display device according to claim 1 or 6, wherein a partition wall having a thickness greater than or equal to the thickness of the light-emitting element is placed between a plurality of the light-emitting elements in the cured film covering the light-emitting elements.

10. The display device according to claim 1 or 6, wherein the light-emitting element is an LED with a side length of 5 μm or more and 700 μm or less.

11. The display device according to claim 1 or 6, further comprising a driving element and a substrate, wherein the driving element is connected to the light-emitting element via wiring, and at least a portion of the wiring extends to the side surface of the substrate.

12. The display device according to claim 1 or 6, further comprising a light-shielding layer between a plurality of light-emitting elements.

13. The display device according to claim 1 or 6, wherein the resin (A) contains one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof.

14. The display device according to claim 1 or 6, wherein the resin composition containing the resin (A) further contains (C) a thermal crosslinking agent.

15. The display device according to claim 1 or 6, wherein the resin composition containing the resin (A) is positive-type photosensitive.