Display device and method for manufacturing the same

Abstract

The present invention addresses the problem of degradation of design of an LED display device due to insufficient concealment of wiring by an insulating film for peripheral wiring insulation, a protection film, an isolating wall and the like. This display device comprises at least metal wires, a cured film, and a plurality of light emitting elements, the light emitting elements having a pair of electrode terminals on one surface thereof, the pair of electrode terminals connecting to a plurality of the metal wires extending in the cured film, the plurality of the metal wires being configured to retain an electrical insulating property due to the cured film, wherein the cured film is a film obtained by curing a resin composition comprising an (A) resin, wherein the transmittance of light of a wavelength 450 nm at a thickness reference 5 μm of the cured film is 0.1% to 79% inclusive.

Description

[Technical Field]

[0001] The present invention relates to a display device such as an LED display and a manufacturing method thereof. [Background technology]

[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 LCDs, plasma displays, and OLED displays. In particular, mini LED displays, which have reduced the size of the LEDs that serve as light sources from the conventional 1mm to 100-700μm, and micro LED displays, which have been miniaturized to less than 100μm, have been attracting attention and are the subject of active research and development. The main features of mini LED displays and micro LED displays include high contrast, fast response, low power consumption, and wide viewing angles. They are expected to be used not only in traditional TVs, smartphones, smartwatches, and other wearable displays, 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), and a configuration in which a bank layer and trace lines are provided on a display substrate, with micro LEDs and a micro driver chip arranged on top of them (see Patent Document 2).Furthermore, a configuration has been proposed in which a planarizing film is formed on a growth substrate on which a light-emitting element body equipped with electrode pads is integrally formed, the planarizing film on the electrode pads is removed to expose the electrode pads, and external electrode pads connected to the electrode pads are formed on the planarizing film, and the external electrode pads are arranged so as to face 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). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-153812 [Patent Document 2] Japanese Patent Publication No. 2020-52404 [Patent Document 3] Japanese Patent Publication No. 2020-68313 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the LED display device described in the above document has a problem in that the wiring is not sufficiently concealed by the surrounding insulating film for insulating wiring, protective film, partition wall, etc., which reduces the design. [Means for solving the problem]

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

[0007] [1] A display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, wherein the light-emitting elements have a pair of electrode terminals on either side thereof, the pair of electrode terminals are connected to a plurality of metal wirings extending in the cured film, and the plurality of metal 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 the cured film at a thickness of 1 μm for light with a wavelength of 450 nm is 0.1% or more and 95% or less.

[0008] [2] A method for manufacturing a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, the method comprising: a step (D1) of arranging the light-emitting elements on a supporting substrate; a step (D2) of forming a resin film made of a resin composition containing (A) resin on the supporting substrate and the light-emitting elements; a step (D3) of exposing and developing the resin film to form a pattern of a plurality of penetrating openings in the resin film; a step (D6) of curing the resin film to form the cured film having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 μm; and a step (D5) of forming the metal wiring on at least a portion of the surface of the cured film and in the opening pattern of the cured film.

[0009] [3] A method for manufacturing a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, the method comprising: a step (E1) of arranging metal pads on a support substrate; a step (E2) of forming a resin film made of a resin composition containing (A) resin on the support substrate and the metal pads; a step (E3) of exposing and developing the resin film to form a pattern of a plurality of penetrating openings in the resin film; a step (E10) of curing the resin film to form the cured film having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 μm; a step (E5) of forming the metal wiring on at least a portion of the surface of the cured film and in the opening pattern of the cured film; and a step (E6) of arranging the light-emitting elements on the cured film so as to maintain electrical connection with the metal wiring. [Effects of the Invention]

[0010] The display device of the present invention has high wiring concealment properties, and can provide a display device with high designability. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a front cross-sectional view showing one embodiment of a display device of the present invention. [Figure 2] 1 is an enlarged front cross-sectional view (upper part) of the designated area A and a bottom view (lower part) of the designated area A excluding the light-emitting element. [Figure 3] This is an enlarged cross-sectional view (upper part) of the top surface of the designated area B, a cross-sectional view (middle part) of the designated area B excluding the wiring in a plane perpendicular to the front of the designated area B, and a bottom view (lower part) of the designated area B excluding the opposing substrate. [Figure 4] FIG. 1 is a front cross-sectional view showing one embodiment of a display device of the present invention in which partition walls are provided. [Figure 5] FIG. 1 is a front cross-sectional view of one embodiment of a display device of the present invention having a configuration in which a driving element is disposed in a cured film. [Figure 6] FIG. 10 is a front cross-sectional view of one embodiment of a display device of the present invention having another configuration in which a driving element is disposed in a cured film. [Figure 7] 1A to 1C are cross-sectional views illustrating a manufacturing process of one embodiment of a display device of the present invention. [Figure 8] 10A to 10C are cross-sectional views illustrating steps in manufacturing another example of the display device of the present invention. [Figure 9] 10A to 10C are cross-sectional views showing the manufacturing process of another example of a display device of the present invention in which a partition wall is provided. [Figure 10] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention. [Figure 11] FIG. 1 is a front cross-sectional view showing one embodiment of the display device of the present invention in which partition walls are provided in a cured film. [Figure 12] FIG. 1 is a front cross-sectional view showing one embodiment of a display device of the present invention in which a conductive film is provided. [Figure 13] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a conductive film is provided. [Figure 14] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a conductive film is provided. [Figure 15] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a conductive film is provided. [Figure 16] FIG. 1 is a front cross-sectional view showing one embodiment of a display device of the present invention in which a light-shielding layer is provided. [Figure 17] FIG. 10 is a front cross-sectional view of an opening pattern in a cured film. [Figure 18] 10A to 10C are cross-sectional views illustrating a manufacturing process of one embodiment of a display device of the present invention in which a partition wall is provided. [Figure 19] 1A to 1C are cross-sectional views illustrating a manufacturing process of one embodiment of a display device of the present invention in which a conductive film is provided. [Figure 20] 1A to 1C are cross-sectional views illustrating a manufacturing process of one embodiment of a display device of the present invention in which a light-shielding layer is provided. [Figure 21] 10A to 10C are cross-sectional views illustrating steps for manufacturing a display device according to another example of the present invention in which a conductive film is provided. [Figure 22] 10A to 10C are cross-sectional views illustrating steps in manufacturing another example of the display device of the present invention. [Figure 23] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a conductive film is provided. [Figure 24] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a conductive film is provided. [Figure 25] 10A to 10C are cross-sectional views illustrating steps for manufacturing another example of a display device of the present invention in which a conductive film is provided. [Figure 26] 10A to 10C are cross-sectional views illustrating steps for manufacturing another example of a display device of the present invention in which a conductive film is provided. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] The display device of the present invention is a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, each of which has a pair of electrode terminals on one surface, the pair of electrode terminals being connected to a plurality of metal wirings extending in the cured film, and the plurality of metal wirings being configured to maintain electrical insulation by the cured film, the cured film being a film obtained by curing a resin composition containing (A) resin, and the transmittance of the cured film at a thickness of 1 μm for light with a wavelength of 450 nm is 0.1% or more and 95% or less.

[0014] The display device of the present invention will be described with reference to FIG. 1 as an example of one embodiment.

[0015] In FIG. 1, the display device 1 has a plurality of light-emitting elements 2 arranged on a counter substrate 5, and a cured film 3 arranged on the light-emitting elements 2. "On the light-emitting elements" does not necessarily mean the surface of the light-emitting elements, but may also mean the upper side of a supporting substrate or the light-emitting elements. In the embodiment shown in FIG. 1, a configuration is illustrated in which a total of three layers are laminated by laminating multiple cured films 3 on a cured film 3 arranged so as to contact at least a portion of the light-emitting elements 2, but the cured film 3 may also be a single layer. The light-emitting element 2 has a pair of electrode terminals 6 on the surface opposite to the surface contacting the counter substrate 5, and each electrode terminal 6 is connected to a metal wiring 4 extending in the cured film 3. Note that if the multiple metal wirings 4 extending in the cured film 3 are covered with the cured film 3, the cured film 3 also functions as an insulating film, so that the configuration maintains electrical insulation. The configuration in which the metal wiring maintains electrical insulation means that the portions of the metal wiring that require electrical insulation are covered with a cured film obtained by curing a resin composition containing (A) resin. Furthermore, the light emitting element 2 is electrically connected to a driving element 8 attached to a light emitting element driving substrate 7 provided at a position opposite to the counter substrate 5 via metal wiring 4 and 4c, thereby controlling the light emission of the light emitting element 2. The light emitting element driving substrate 7 is also electrically connected to the metal wiring 4 via, for example, solder bumps 10. Furthermore, a barrier metal 9 may be provided to prevent diffusion of metal such as the metal wiring 4. Note that, hereinafter, the metal wiring 4c in the figures may penetrate the light emitting element driving substrate 7 and be connected to the driving element 8.

[0016] The cured film 3 is a film obtained by curing a resin composition containing the (A) resin described below, and it is important that the transmittance of light at a wavelength of 450 nm at a standard thickness of 1 μm is 0.1% or more and 95% or less. This allows the cured film 3 to conceal the metal wiring 4, making it difficult to see the metal wiring 4 from the outside and improving the design.

[0017] The cured film 3 is a film obtained by curing a resin composition containing the (A) resin described below, and the transmittance of light at a wavelength of 450 nm at a standard thickness of 5 μm of the cured film 3 is preferably 0.1% or more and 79% or less. This allows the cured film 3 to conceal the metal wiring 4, making it difficult to see the metal wiring 4 from the outside and improving the design.

[0018] The cured film 3 is a film obtained by curing a resin composition containing the (A) resin described below, and the transmittance of light at a wavelength of 450 nm at a standard thickness of 1 μm of the cured film 3 is preferably 0.1% or more and 25% or less. This allows the cured film 3 to conceal the metal wiring 4, making it difficult to see the metal wiring 4 from the outside, thereby improving the design, and further increasing visibility by reducing external light reflection and improving contrast.

[0019] If the transmittance of light at a wavelength of 450 nm at a standard thickness of 1 μm through the cured film 3 is less than 0.1%, there is a concern that problems such as a decrease in the sensitivity and resolution of the resin film before curing may occur. If the transmittance of light exceeds 95%, there is a concern that problems such as a decrease in hiding power may occur, making the metal wiring visible from the outside may occur.

[0020] The light transmittance at a wavelength of 450 nm when the cured film has a thickness of 1 μm may be measured by peeling the cured film from the display device, or by measuring the light transmittance of a cured film prepared under the conditions of the method for evaluating the light transmittance of a cured film described below. When the cured film is formed in multiple layers, any of the cured films may be used for the measurement.

[0021] There are no particular limitations on the material of the metal wiring 4, and known materials can be used. Examples include gold, silver, copper, aluminum, nickel, titanium, molybdenum, and alloys containing these, with copper being preferred. The metal wiring 4 may also include an electrode.

[0022] In the display device of the present invention, the metal wiring may be a conductive film.

[0023] The conductive film is not particularly limited, and examples thereof include 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, and photosensitive conductive pastes containing organic substances and conductive particles. However, 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).

[0024] These conductive films can be formed by, for example, 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; or a method in which a metal foil is bonded to a substrate and then etched.

[0025] Regarding the photosensitive conductive paste containing an organic substance and conductive particles, examples of the organic substance include epoxy resin, phenoxy resin, acrylic copolymer, and epoxy carboxylate compound. Two or more of these may be contained. An organic substance having a urethane bond may also be contained. The inclusion of an organic substance having a urethane bond can improve the flexibility of the wiring. Furthermore, the organic substance preferably exhibits photosensitivity, which allows for the easy formation of fine wiring patterns by photolithography. Photosensitivity can be achieved by, for example, adding a photopolymerization initiator or a component having an unsaturated double bond.

[0026] Conductive particles are particles with an electrical resistivity of 10 -5Refers to particles made up of substances with a resistance of Ω·m or less. Materials that make up conductive particles include, for example, silver, gold, copper, platinum, lead, tin, nickel, aluminum, tungsten, molybdenum, chromium, titanium, indium, alloys of these metals, and carbon particles.

[0027] The conductive film also includes an electrode. Examples of a display device using a conductive film are shown in FIGS.

[0028] As another embodiment of the display device of the present invention, as shown in Fig. 10, a configuration is exemplified in which a cured film 21 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 21 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 or a resin sheet containing the (A) resin, or may be made of a material other than a cured film obtained by curing a resin composition or a resin sheet containing the (A) resin, and known materials such as epoxy resin, silicone resin, and fluororesin may be used.

[0029] In the present invention, the light emitting element driving substrate 7 may be a substrate having elements with a driving function, and preferably has driving elements 8 connected thereto.

[0030] There are no particular limitations on the light-emitting element driving substrate 7, and known substrates can be used, such as glass substrates, sapphire substrates, printed wiring boards, TFT array substrates, and ceramics.

[0031] In the present invention, the total thickness of the cured film is preferably 5 to 100 μm.

[0032] When the total thickness of the cured film is 5 to 100 μm, the light transmittance of the cured film 3 is low, so that the cured film 3 conceals the metal wiring 4, making the metal wiring 4 less visible from the outside and improving the design. 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. In addition, visibility can be improved by reducing external light reflection and improving contrast.

[0033] 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, when multiple cured films 3 are stacked as shown in FIG. 1, the area indicated by 20 in FIG. 1 represents the total thickness of the cured film layer. The total thickness is preferably 7 to 70 μm, more preferably 8 to 60 μm. If the thickness is less than 5 μm, the metal wiring is not sufficiently protected, raising concerns about wiring defects such as short circuits. If the thickness exceeds 100 μm, there is a concern about insufficient light extraction efficiency and may cause inconvenience in terms of reducing the height of the display device itself, suppressing wiring defects such as short circuits due to shorter wiring distances, suppressing loss, and improving high-speed response.

[0034] When a plurality of cured films are laminated, the number of layers of the cured films 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. Furthermore, by having two or more layers, the number of metal wirings that can be connected to the light-emitting elements can be increased, allowing a plurality of light-emitting elements to be arranged. Furthermore, from the viewpoints of suppressing wiring defects such as short circuits caused by a low-profile package or a short wiring distance, reducing loss, and improving high-speed responsiveness, the cured film preferably has 10 or less layers.

[0035] In the present invention, the cured film is provided with an opening pattern penetrating through the film in the thickness direction, and the metal wiring is disposed at least in the opening pattern, and it is preferable that the maximum length of the bottom surface of the metal wiring formed at the position in contact with the light-emitting element is 2 to 20 μm.

[0036] 2 shows an enlarged front cross-sectional view (upper portion) of the designated area A in FIG. 1 and a bottom view (lower portion) of the designated area A excluding the light-emitting element. In the enlarged front cross-sectional view (upper portion) of the designated area 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 metal wiring 4 formed in the opening pattern 12 is shown. The bottom portion 13 of the metal wiring 4 shows the shape of the metal wiring 4 at the point where the metal wiring 4 extends into the cured film 3 and contacts the light-emitting element 2 and the electrode terminal 6 of the light-emitting element 2.

[0037] In the bottom view (lower portion) of the designated area A of FIG. 2 , excluding the light-emitting element, the bottom portion 13 of the metal wiring 4 extending to the cured film 3 is viewed from below with the light-emitting element 2 removed, showing the bottom portion 13. In the bottom view (lower portion) of the designated area A of FIG. 2 , excluding the light-emitting element, the bottom portion 13 of the metal wiring 4 extending to the cured film 3 is viewed from below with the light-emitting element 2 removed, showing the bottom portion 13. The shape of the bottom portion 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 longest diameter is defined as the longest length 14. 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 portion 13 in the bottom view (lower portion) of the designated area A of FIG. 2 , excluding the light-emitting element, shows an example of a circular shape.

[0038] This configuration allows for the application of minute light-emitting elements and the high-density packaging of multiple light-emitting elements, resulting in a display device with high-resolution light-emitting elements in a wide range of sizes. Furthermore, it is possible to form fine metal wiring, which increases the number of wirings that can be formed per unit area, thereby reducing the overall thickness of the cured film. Because the cured film 3 has low light transmittance, the cured film 3 conceals the metal wiring 4, making it difficult to see from the outside, thereby improving design. Furthermore, it is possible to reduce the height of the display device itself that includes light-emitting elements, reduce wiring defects such as wiring shorts due to shorter wiring distances, reduce loss, and improve high-speed response. In addition, visibility can be improved by reducing external light reflection and improving contrast.

[0039] 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 metal wiring is preferably 2 to 15 μm, more preferably 2 to 10 μm, and even more preferably 2 to 5 μm. 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 be detrimental to the application of minute light-emitting elements and high-density mounting.

[0040] In the present invention, the maximum length of the bottom surface of the metal wiring formed in the vicinity of the light emitting element may be 2 to 20 μm.

[0041] This configuration allows for the application of minute light-emitting elements and the high-density packaging of multiple light-emitting elements, resulting in a display device with high-resolution light-emitting elements in a wide range of sizes. Furthermore, it is possible to form fine metal wiring, which increases the number of wirings that can be formed per unit area, thereby reducing the overall thickness of the cured film. Because the cured film 3 has low light transmittance, the cured film 3 conceals the metal wiring 4, making it difficult to see from the outside, thereby improving design. Furthermore, it is possible to reduce the height of the display device itself that includes light-emitting elements, reduce wiring defects such as wiring shorts due to shorter wiring distances, reduce loss, and improve high-speed response. In addition, visibility can be improved by reducing external light reflection and improving contrast.

[0042] 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 metal wiring is preferably 2 to 15 μm, more preferably 2 to 10 μm, and even more preferably 2 to 5 μm. 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 be detrimental to the application of minute light-emitting elements and high-density mounting.

[0043] The thickness of the cured film is preferably 1.1 to 4.0 times the thickness of the metal wiring.

[0044] The thickness of the metal wiring, as explained in the enlarged front cross-sectional view (upper portion) of designated area A in FIG. 2 , refers to the thickness of the metal wiring 4a arranged on the surface of the cured film 3, and does not include the thickness of the metal wiring 4b extending into the opening pattern penetrating the cured film 3 in the thickness direction. The thickness of the metal wiring is preferably 0.1 to 10 μm, more preferably 3 to 10 μm. By setting the thickness of the metal wiring to 0.1 to 10 μm, 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, reduce loss, and improve high-speed response. Furthermore, by setting the thickness to 3 to 10 μm, it is possible to reduce wiring resistance, which contributes to reduced power consumption and improved brightness.

[0045] The thickness of the cured film, as explained with reference to the enlarged front cross-sectional view (upper part) of designated area A in FIG. 2, refers to the thickness of the cured film 3a that covers the metal wiring 4a.

[0046] This allows for the production of a highly reliable cured film that also functions as a protective film for appropriate metal wiring and suppresses wiring defects such as short circuits.

[0047] The thickness of the metal 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 metal wiring closer to the bumps 10 is thicker than the thickness of the metal 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.

[0048] In the present invention, it is preferable that the cured film covers the surfaces of the light emitting element other than the light extraction surface.

[0049] As an example, Figure 3 shows an enlarged cross-sectional view (upper part) of the top surface of the designated area B in Figure 1, a cross-sectional view (middle part) of the designated area B excluding the wiring in a plane perpendicular to the front of the designated area B, and a bottom view (lower part) of the designated area B excluding the opposing substrate.

[0050] In the enlarged top cross-sectional view (upper part) of the designated area B in Figure 3, the light-emitting element 2 is covered with a cured film 3, and metal wiring 4 that connects to the electrode terminal 6 of the light-emitting element and extends into the cured film 3 is shown from above.

[0051] In the cross-sectional view (middle part) of FIG. 3, in which the wiring is removed and taken along a plane perpendicular to the front surface, it is shown that the periphery of the light emitting element 2 is covered with a cured film 3.

[0052] In the bottom view (lower part) of the designated area B of Figure 3 excluding the opposing substrate, it is shown that the periphery of the light-emitting element 2 is covered with the hardened film 3, but one surface of the light-emitting element 2 is not covered with the hardened film 3.

[0053] 1 and 3, by covering the entire side surface and upper 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 caused by 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.

[0054] The cured film 3 covering the surfaces of the light emitting element 2 other than the light extraction surface has the above-mentioned concealing properties, making the metal wiring 4 less visible from the outside and improving the design.

[0055] 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.

[0056] 4, it is preferable to have partition walls 15 in a repeating pattern according to the number of pixels of a display device 1 having light-emitting elements 2, i.e., between or around each light-emitting element 2. This configuration is preferable because it makes it easier to attach the light-emitting element to an opposing substrate 5.

[0057] The thickness of the partition wall is preferably larger than the thickness of each light emitting element, and specifically, is preferably 5 μm to 120 μm.

[0058] The partition walls may be made of a cured film obtained by curing a resin composition containing the (A) resin, or may be made of 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. 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, the light emitted from the light-emitting element toward the partition wall can be reflected to increase the light extraction efficiency, and a reflective portion may be provided on the side surface of the partition wall to improve brightness. The reflective portion is, for example, a portion containing a white pigment.

[0059] 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. As another embodiment in which partition walls are provided, as shown in FIG. 11, a configuration in which partition walls 15 are provided between or around the light emitting elements 2 in the cured film 3 covering the light emitting elements 2 is exemplified. 11 may be made of a material other than the resin composition containing resin (A), and 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.

[0060] 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.

[0061] The light emitted from the light emitting element toward the partition wall can be reflected to increase the light extraction efficiency, and a reflective portion may be provided on the side surface of the partition wall to improve brightness. The reflective portion is, for example, a portion containing a white pigment.

[0062] In the present invention, a light diffusing layer may be provided around the light emitting element, the cured film, or the metal wiring.

[0063] 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.

[0064] An LED is composed of a PN junction, where a P-type semiconductor and an N-type semiconductor are joined together. When a forward voltage is applied to an LED, electrons and holes move within the chip, causing a current to flow. When this happens, the electrons and holes combine, creating an energy difference, and the excess energy is converted into light energy, resulting in light emission. The wavelength of the 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 color of the emitted light. Furthermore, while white is generally 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.

[0065] LEDs can be shaped like a bullet, chip, or polygon, but chip or polygonal shapes are preferred from the perspective of miniaturization. Furthermore, it is preferable for the length of one side of the LED to be between 5 μm and 700 μm, so that multiple chips can be arranged, and it is even more preferable for the length of one side of the LED to be between 5 μm and 100 μm.

[0066] As a method for mounting LEDs on a substrate such as the light-emitting element driving substrate 7 on which the cured film 3 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.

[0067] LEDs can be mounted on a substrate in several ways, including arranging red, green, and blue LEDs in a matrix at predetermined positions on the substrate, and arranging a single type of LED, such as red or blue LEDs or ultraviolet LEDs, on the substrate. The former method can use red, green, and blue LEDs, respectively, or vertically stacked red, green, and blue LEDs. The latter method makes it easier to mount an array of LEDs. In this case, wavelength conversion materials such as quantum dots can be used to create red, green, and blue subpixels, enabling a full-color display.

[0068] Known wavelength converting materials can be used.

[0069] For example, when using blue-emitting LEDs, it is preferable to first fabricate an LED array substrate on which only blue-emitting LEDs 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 blue-emitting LEDs.

[0070] On the other hand, when using ultraviolet LEDs that emit ultraviolet light, it is preferable to first fabricate an LED array substrate on which only ultraviolet LEDs 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. This makes it possible to suppress the difference in light emission angle depending on the color of the subpixels.

[0071] As the wavelength conversion layer, a known material can be used, and a color filter or the like may also be used as needed.

[0072] Examples of the counter substrate in the present invention include a glass plate, a resin plate, and a resin film. The material of the glass plate is preferably alkali-free glass. The material of the resin plate and the resin film is preferably polyester, (meth)acrylic polymer, transparent polyimide, polyethersulfone, etc. The thickness of the glass plate and the resin plate is preferably 1 mm or less, and more preferably 0.8 mm or less. The thickness of the resin film is preferably 100 μm or less.

[0073] The display device of the present invention preferably includes a driving element, and the light-emitting elements are electrically connected to the driving element through metal wiring extending into the cured film. By including a driving element in the display device and electrically connecting the light-emitting elements to the driving element through metal wiring extending into the cured film, it is possible to individually switch-drive a plurality of light-emitting elements. Examples of the driving element include a driver IC, and a plurality of driver ICs may be used for each LED or each unit of red, blue, and green LEDs, depending on their functions.

[0074] As a configuration of the arrangement of 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, as shown in Fig. 5, is preferred. Also, a configuration in which the driving elements 8 are arranged in the cured film 3 at a position above the light-emitting element 2, as shown in Fig. 6, is also preferred. This makes it possible to suppress wiring defects such as short circuits due to shorter wiring distances, reduce loss, and improve high-speed response.

[0075] 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 metal wiring, and at least a portion of the metal 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 metal wiring, and at least a portion of the metal wiring extending to a side surface of the substrate, it is possible to individually switch and drive a plurality of light-emitting elements, and it is possible to 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.

[0076] The substrate, like the light-emitting element drive substrate 7, is not particularly limited and can be any known substrate. Examples include glass substrates, sapphire substrates, printed wiring boards, TFT array substrates, and ceramics. The metal wiring extending at least partially along the side of the substrate can be made of, for example, gold, silver, copper, aluminum, nickel, titanium, tungsten, aluminum, tin, chromium, or alloys containing these. The metal wiring extending along the side of the substrate can be formed by, for example, 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; or etching methods after bonding a metal foil to the substrate. Grooves may also be formed along the side of the substrate. In this case, the grooves reliably separate adjacent metal wiring, thereby preventing short circuits between the metal wiring. Grooves for arranging side conductor lines can be formed by cutting, etching, laser processing, or other methods.

[0077] As a configuration of the metal wiring, for example, a configuration as shown in FIG. 1 or 4c in FIG. 4 is preferable.

[0078] In the present invention, the metal wiring may be a conductive film.

[0079] Examples of conductive films include 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 substances and conductive particles, but other known materials may also be used.

[0080] 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).

[0081] These conductive films can be formed by, for example, 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; or a method in which a metal foil is bonded to a substrate and then etched.

[0082] In a photosensitive conductive paste containing an organic substance and conductive particles, the content of the conductive particles is preferably 60 to 90% by mass. When the conductive layer contains an organic substance, disconnection at curved surfaces or bent portions can be suppressed, and conductivity can be improved. If the content of the conductive particles is less than 60% by mass, the probability of contact between the conductive particles decreases, resulting in a decrease in 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 is more likely to occur at bent portions. The content of the conductive particles is preferably 80% by mass or less.

[0083] Examples of organic materials include epoxy resins, phenoxy resins, acrylic copolymers, and epoxy carboxylate compounds. Two or more of these may be contained. An organic material having a urethane bond may also be contained. By containing an organic material having a urethane bond, the flexibility of the wiring can be improved. Furthermore, the organic material preferably exhibits photosensitivity, which allows for the easy formation of fine wiring patterns by photolithography. Photosensitivity can be achieved by, for example, containing a photopolymerization initiator or a component having an unsaturated double bond.

[0084] The conductive particles in the present invention are particles having an electrical resistivity of 10 -5 Conductive particles refer to particles composed of a substance with a resistivity of Ω·m or less. Examples of materials that make up 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 process described below is suppressed, resulting in suppressed volumetric shrinkage of the entire conductive film and improved flexibility.

[0085] The conductive particles preferably have an average particle diameter of 0.005 to 2 μm. When two or more types of conductive particles are contained, the average particle diameter here refers to the average particle diameter of the larger particles. When the conductive particles have an average particle diameter of 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 conductive particles more preferably have an average particle diameter of 0.01 μm or more. On the other hand, when the conductive particles have an average particle diameter of 2 μm or less, it becomes easier to form a desired wiring pattern. The conductive particles more preferably have an average particle diameter of 1.5 μm or less.

[0086] The thickness of the conductive film is preferably 2 to 10 μm. 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.

[0087] As a configuration of the conductive film, for example, a configuration as shown in 26 in FIGS. 12 to 15 is preferable.

[0088] 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.

[0089] The light-shielding layer 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 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 fine metal 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. Dyes may also be used. Two or more colorants may be used.

[0090] The resin composition containing the (A) resin and the (E) colorant may be given photosensitivity, and a (B) photosensitizer described below may be used.

[0091] A preferred method for producing a resin composition containing (A) resin and (E) colorant is to use a disperser to disperse a resin solution containing (A) resin, (E) colorant, and optionally a dispersant and an organic solvent, to prepare a colorant dispersion with a high colorant concentration, and then add (A) resin and, optionally, other components such as a photosensitizer, followed by stirring. Filtration may be performed as needed.

[0092] 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 their efficient dispersion and 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 to 1.0 mm. When the primary particle diameter of the (E) 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 to 0.10 mm. 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.

[0093] The resin composition containing the (A) resin and the (E) colorant can be applied to various substrates, dried, and then heat-treated to obtain a light-shielding layer. If the resin composition is photosensitive, it can be exposed to actinic rays as described below, and then developed and heat-treated as described below to obtain a patterned light-shielding layer.

[0094] The thickness of the light-shielding layer is preferably 0.1 to 5 μm. When the thickness of the light-shielding layer is 0.1 μm or more, light leakage from the light-emitting elements 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 elements and color mixing between pixels can be suppressed and contrast can be improved without significantly impairing light extraction efficiency. The thickness of the light-shielding layer is more preferably 4 μm or less.

[0095] 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 (a*, b*) measured from the glass surface is preferably −0.5≦a*≦1.0 and −1.0≦b*≦0.5, and more preferably −0.5≦a*≦0.5 and −1.0≦b*≦0.4. The reflective chromaticity is an index of the color tone of the image reflected in the colored film, and the closer the chromaticity is to (a*, b*) = (0.0, 0.0), the more achromatic the reflective color tone. On the other hand, the reflective color tone of black display in liquid crystal display devices and organic electroluminescent (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.

[0096] The reflection chromaticity (L*, a*, b*) of the colored film was obtained by measuring the total reflection chromaticity (SCI) of light incident from a transparent substrate using a spectrophotometer (CM-2600d; manufactured by Konica Minolta, Inc.) calibrated with a white calibration plate (CM-A145; manufactured by Konica Minolta, Inc.) under the following measurement conditions: standard illuminant D65 (color temperature 6504K), viewing angle 2° (CIE1976), atmospheric pressure, and 20°C.

[0097] A preferred configuration of the light-shielding layer is, for example, the configuration shown by 27 in Fig. 16. The light-shielding layer 27 may be in contact with the light-emitting element 2 or may be separated from it.

[0098] In the present invention, the cured film obtained by curing the resin composition containing the (A) resin has a light transmittance of 0.1% to 95% at a wavelength of 450 nm at a thickness of 1 μm, thereby providing the aforementioned concealing properties, making it difficult to see the metal wiring from the outside and improving the design.

[0099] The transmittance of light at a wavelength of 450 nm at a standard thickness of 5 μm of the cured film is preferably 0.1% to 79%, which makes the metal wiring less visible from the outside and improves the design.

[0100] The transmittance of light at a wavelength of 450 nm at a standard thickness of 1 μm of the cured film is preferably 0.1% to 25%, which makes the metal wiring less visible from the outside, improving design, and further increasing visibility by reducing external light reflection and improving contrast.

[0101] If the transmittance of light at a wavelength of 450 nm at a thickness of 1 μm for a cured film is less than 0.1%, there is a concern that problems such as a decrease in the sensitivity and resolution of the resin film before curing may occur.If the transmittance of light exceeds 95%, there is a concern that problems such as a decrease in hiding power may occur, making the metal wiring visible from the outside.

[0102] The (A) resin preferably has high heat resistance, specifically, one that is less susceptible to resin deterioration at high temperatures of 160° C. or higher during or after heat treatment. 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.

[0103] 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. 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.

[0104] For the protection of metal wiring, it is preferable that the processability is excellent even for a thick film having a thickness of 10 μm or more. The resin (A) is not particularly limited, but is preferably an alkali-soluble resin from the viewpoint of reducing environmental impact. Alkali-solubility is determined by applying a solution of the resin dissolved in γ-butyrolactone to a silicon wafer and prebaking at 120°C for 4 minutes to form a prebaked film with a thickness of 10 μm±0.5 μm. 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 then rinsed with pure water to determine the film thickness reduction. A prebaked film with a dissolution rate of 50 nm / min or higher is defined as alkali-soluble.

[0105] 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.

[0106] Polyimide, polyimide precursor, polybenzoxazole, and polybenzoxazole precursor will be described.

[0107] The polyimide is not particularly limited as long as it has an imide ring. The polyimide precursor is not particularly limited as long as it has a structure that becomes a polyimide having an imide ring by dehydration ring closure, and can contain polyamic acid, polyamic acid ester, etc. The polybenzoxazole is not particularly limited as long as it has an oxazole ring. The polybenzoxazole precursor is not particularly limited as long as it has a structure that becomes a polybenzoxazole having a benzoxazole ring by dehydration ring closure, and can contain polyhydroxyamide, etc.

[0108] 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.

[0109] [ka]

[0110] In general formula (1), V represents a tetravalent to decavalent organic group having 4 to 40 carbon atoms, and W represents a divalent to octavalent organic group having 4 to 40 carbon atoms. a and b each represent an integer of 0 to 6. R 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.

[0111] [ka]

[0112] 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 4 each 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.

[0113] [ka]

[0114] In the general formula (3), T and U each independently represent a divalent to octavalent organic group having 4 to 40 carbon atoms.

[0115] In order to impart alkali solubility to the (A) resin, it is preferable that a+b>0 in general formula (1). Furthermore, 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.

[0116] 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.

[0117] 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.

[0118] 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, and more preferably 70 mol% or more, of the total number of structural units.

[0119] In the above general formula (1), V-(R 1 ) a In the above general formula (2), (OH) c -X-(COOR 3 ) eIn the general formula (3), T represents an acid residue. V is a tetravalent to decavalent organic group having 4 to 40 carbon atoms, and is preferably an organic group having 4 to 40 carbon atoms containing an aromatic ring or a cyclic aliphatic group. X and T are divalent to octavalent organic groups having 4 to 40 carbon atoms, and is preferably an organic group having 4 to 40 carbon atoms containing an aromatic ring or an aliphatic group.

[0120] 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'-biphenyltetracarboxylic acid, and 2,3,3',4'-biphenyltetracarboxylic 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.

[0121] [ka]

[0122] In the formula, R 17 represents an oxygen atom, C(CF3)2, or C(CH3)2. 18 and R 19 represents a hydrogen atom or a hydroxyl group.

[0123] These acids can be used as they are, or as acid anhydrides, halides, or activated esters.

[0124] 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.

[0125] 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'-diaminodiphenyl; 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-phenylene Diamine, 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'-diaminobiphenyl, 2 Aromatic diamines such as 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 these aromatic rings have been substituted with alkyl groups or fluoroalkyl groups having 1 to 10 carbon atoms, halogen atoms, etc., 2,4-diamino-1,3,5-triazine (guanamine), 2,4-diamino-6-methyl-1,3,5-triazine (acetoguanamine), 2,4-diamino-6-phenyl-1,Examples of such diamines include diamines having a nitrogen-containing heteroaromatic ring such as 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.

[0126] [ka]

[0127] In the formula, R 20 represents an oxygen atom, C(CF3)2, or C(CH3)2. 21 ~R 24 each independently represents a hydrogen atom or a hydroxyl group.

[0128] Among these, it is preferable to contain at least one diamine having the structure shown below from the viewpoint of improving the alkali developability and the transmittance of the (A) resin and its cured film.

[0129] [ka]

[0130] In the formula, R 20 represents an oxygen atom, C(CF3)2, or C(CH3)2. 21 ~R 22 each independently represents a hydrogen atom or a hydroxyl group.

[0131] These diamines can be used as they are, or as diisocyanate compounds or trimethylsilylated diamines obtained by reacting the diamines with phosgene.

[0132] The (A) resin 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.

[0133] [ka]

[0134] 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.

[0135] Examples of the group represented by general 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.

[0136] By including a group selected from an alkylene group and an alkylene ether group in the (A) resin, 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.

[0137] The (A) resin preferably contains a group selected from the alkylene group and alkylene ether group as W in the general formula (1) or Y in the general formula (2). This improves the mechanical properties, particularly elongation, of the (A) resin and its cured film, and further improves the light transmittance at 450 nm before and after curing. It also promotes ring closure in a cured film of the resin composition by low-temperature heat treatment, thereby providing high chemical resistance, high adhesion to substrate metals, and resistance to a constant temperature and humidity test (HAST).

[0138] 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 4-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 Corporation).

[0139] These diamines may also contain bonds such as -S-, -SO-, -SO2-, -NH-, -NCH3-, -N(CH2CH3)-, -N(CH2CH2CH3)-, -N(CH(CH3)2)-, -COO-, -CONH-, -OCONH-, and -NHCONH-.

[0140] The diamine residues containing a group selected from an alkylene group and an alkylene ether group preferably account for 5 mol % or more, more preferably 10 mol % or more, of all diamine residues. The diamine residues are preferably 40 mol % or less, more preferably 30 mol % or less, of all diamine residues. By adjusting the content 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 is 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 testing (HAST).

[0141] 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 bis(3-aminopropyl)tetramethyldisiloxane, bis(p-aminophenyl)octamethylpentasiloxane, or the like in an amount of 1 to 15 mol % of the total diamine residues. Copolymerization within this range is preferred in terms of improving adhesion to substrates such as silicon wafers and not reducing solubility in alkaline solutions.

[0142] (A) A resin having an acidic group at the end of its main chain can be obtained by capping the ends of the 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.

[0143] 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 (A) resin.

[0144] The (A) resin preferably has a weight-average molecular weight of 10,000 or more and 100,000 or less. A weight-average molecular weight of 10,000 or more can improve the mechanical properties of the cured film after curing. A weight-average molecular weight of 20,000 or more is more preferable. On the other hand, a weight-average molecular weight of 100,000 or less can improve developability with various developers, and a weight-average molecular weight of 50,000 or less is further preferable because it can improve developability with alkaline solutions.

[0145] 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.

[0146] The content of the (A) resin is preferably 3 to 55% by mass, and more preferably 5 to 40% by mass, based on 100% by mass of all components including the solvent. By keeping the content within this range, it is possible to achieve a viscosity suitable for spin coating or slit coating.

[0147] 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.

[0148] From the viewpoint of reducing the transmittance, the phenol resin is preferably a wholly aromatic phenol resin made of a phenol compound and an aromatic aldehyde compound.

[0149] In the present invention, the resin composition containing (A) resin preferably contains (B) a photosensitizer (hereinafter, sometimes referred to as component (B)).

[0150] It is preferable that the resin composition containing the resin (A) further contains a photosensitizer (B), because this imparts photosensitivity to the resin composition and enables the formation of a fine opening pattern.

[0151] The (B) photosensitizer is a compound whose chemical structure changes in response to ultraviolet light, and examples thereof include a photoacid generator, a photobase generator, a photopolymerization initiator, etc. When a photoacid generator is used as the (B) component, acid is generated in the irradiated portion of the photosensitive resin composition, increasing the solubility of the irradiated portion in an alkaline developer, thereby obtaining a positive pattern in which the irradiated portion dissolves.

[0152] (B) When a photobase generator is contained as a photosensitizer, a base is generated in the irradiated parts of the resin composition, which reduces the solubility of the irradiated parts in an alkaline developer, thereby making it possible to obtain a negative pattern in which the irradiated parts are insolubilized.

[0153] When a photopolymerization initiator (B) is used as a photosensitizer, radicals are generated in the irradiated area of ​​the resin composition, radical polymerization proceeds, and the resin composition becomes insoluble in an alkaline developer, forming a negative pattern. In addition, UV curing during exposure is accelerated, improving sensitivity.

[0154] In the present invention, the cured film obtained by curing the resin composition containing (A) resin has a light transmittance of 0.1% or more and 95% or less at a wavelength of 450 nm at a thickness of 1 μm. This allows the cured film to have the aforementioned hiding properties, making the metal wiring less visible from the outside and improving the design. If the light transmittance is less than 0.1%, there is a concern that problems such as a decrease in the sensitivity and resolution of the resin film before curing may occur. If the light transmittance exceeds 95%, there is a concern that the hiding properties may decrease and problems such as the metal wiring being visible from the outside may occur.

[0155] In order to obtain such properties, the (B) photosensitizer is preferably one in which the (B) photosensitizer itself has low light transmittance at a wavelength of 450 nm and undergoes little structural change upon heat treatment, one in which the reaction product between the (B) photosensitizer and the (A) resin or thermal crosslinking agent or the like has low light transmittance, or one in which the decomposition product of the (B) photosensitizer itself or a reaction product derived from the decomposition product has low light transmittance.

[0156] From the viewpoint of microprocessability, it is preferable that the resin composition containing the (A) resin has positive photosensitivity. Furthermore, it is preferable that the resin composition containing the (A) resin and the (B) photosensitizer has positive photosensitivity.

[0157] Among the above-mentioned (B) photosensitizers, photoacid generators are preferred from the viewpoints of opacifying properties, 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.

[0158] The quinone diazide compound is preferably a compound in which a naphthoquinone diazide sulfonic acid is bonded to a compound having a phenolic hydroxyl group via an ester bond. The compound having a phenolic hydroxyl group used here may be a known compound, and examples thereof include those in which 4-naphthoquinone diazide sulfonic acid or 5-naphthoquinone diazide sulfonic acid is introduced via an ester bond, but other compounds may also be used.

[0159] Preferably, 50 mol % or more of the functional groups of the compound having a phenolic hydroxyl group are substituted with quinone diazide. Using a quinone diazide compound substituted by 50 mol % or more reduces the affinity of the quinone diazide compound for alkaline aqueous solutions. 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. This results in a higher dissolution rate ratio between the exposed and unexposed portions of the composition, allowing for the production of high-resolution patterns.

[0160] By incorporating 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, as well as a broadband including these. Furthermore, the (B) photosensitizer may be incorporated alone or in combination of two or more, thereby obtaining a highly sensitive resin composition.

[0161] 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.

[0162] 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-2). Compound (B-2) exhibits high absorption in the i-line region of a mercury lamp, making it suitable for i-line exposure. Furthermore, compound (B-2) decomposes or reacts with resin (A) during curing to cause coloration, thereby reducing the transmittance of light at 450 nm. This is preferable from the viewpoint of light transmittance after heat treatment. When the photosensitizer is a single component consisting of compound (B-2) alone or in a mixture with other components, it is preferable that compound (B-2) be contained in an amount of 46% by mass or more. When compound (B-1) and compound (B-2) are used as a mixture, the content of compound (B-2) is preferably 46% by mass or more but 100% by mass or less of the total amount of compound (B-1) and compound (B-2) used as the photosensitizer. By adjusting the content ratio within this range, a cured film having low light transmittance can be obtained.

[0163] 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.

[0164] The molecular weight of the (B) photosensitizer is preferably 300 or more, more preferably 350 or more, and 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.

[0165] 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.

[0166] The content of the (B) photosensitizer is preferably 0.1 to 100 parts by mass relative to 100 parts by mass of the (A) resin. When the content of the (B) photosensitizer is 0.1 to 100 parts by mass, photosensitivity can be imparted while maintaining the heat resistance, chemical resistance, and mechanical properties of the film after heat treatment.

[0167] 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, per 100 parts by mass of the (A) component. Also, the content is 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.

[0168] When the (B) photosensitizer contains a sulfonium salt, phosphonium salt, or 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, per 100 parts by mass of the (A) resin. Also, the content is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and particularly preferably 50 parts by mass or less. When the content 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.

[0169] When a photobase generator is contained as the (B) photosensitizer, specific examples of the photobase generator include amide compounds and ammonium salts.

[0170] 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.

[0171] 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.

[0172] 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, 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, resolution after development can be improved.

[0173] 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 multiple photopolymerization 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 preferred, and an α-aminoketone-based photopolymerization initiator, an acylphosphine oxide-based photopolymerization initiator, or an oxime ester-based photopolymerization initiator is even more preferred.

[0174] When a photopolymerization initiator 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, 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, resolution after development can be improved.

[0175] In the present invention, it is preferable that the resin composition containing the (A) resin further contains a (C) colorant, and that the (C) colorant contains a (C-1) colorant having an absorption maximum in a wavelength range of 400 nm or more and 490 nm or less (hereinafter, these may be referred to as the (C) component or the (C-1) component).

[0176] (C) Colorants include thermochromic compounds, dyes, pigments, etc. Among these, from the viewpoints of heat resistance, sensitivity, and resolution, it is preferable to use one or more of dyes and organic pigments, and dyes are more preferable.

[0177] When the component (C) contains the component (C-1), the component absorbs light in the wavelength range of 400 nm or more and 490 nm or less, reducing the amount of light that transmits. This allows the cured film of the present invention to have a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 μm. The cured film has concealing properties, making it difficult to see the metal wiring from the outside and improving the design properties.

[0178] Preferably, the component (C-1) is a colorant having an absorption maximum in the wavelength range of 420 nm or more and 480 nm or less, more preferably in the wavelength range of 430 nm or more and 470 nm or less.

[0179] The component (C-1) has the property of transmitting light with a wavelength of 350 nm to 390 nm, which is a part of the exposure wavelength, so that both sensitivity and resolution to the exposure wavelength can be achieved. Specifically, a 10% concentration ink comprising the colorant (C-1) and a solvent is used. -5 In a 100 mol / L compound solution, the transmittance of light with a wavelength of 350 nm to 390 nm is preferably 40% or more, and more preferably 70% or more.

[0180] The component (C-1) may contain at least one type of material, and examples thereof include a method using one type of thermochromic compound and one type of dye or organic pigment, a method using a mixture of two or more types of thermochromic compounds, dyes or organic pigments, and a method using a combination of one or more types of thermochromic compounds, one or more types of dyes and one or more types of organic pigments.

[0181] Examples of the component (C-1) include yellow dyes, orange dyes, etc. Examples of the type of dye include oil-soluble dyes, disperse dyes, reactive dyes, acid dyes, and direct dyes.

[0182] Examples of the skeleton structure of the dye used as component (C-1) include, but are not limited to, anthraquinones, methines, quinolines, perinones, etc. These dyes may be used alone or as metal-containing complex salts. Specific examples of dyes that can be used include, but are not limited to, Sumilan and Lanyl dyes (Sumitomo Chemical Co., Ltd.), Orasol, Oracet, Filamid, and Irgasperse dyes (Ciba Specialty Chemicals Co., Ltd.), Zapon, Neozapon, Neptune, and Acidol dyes (BASF Ltd.), Kayaset and Kayakalan dyes (Nippon Kayaku Co., Ltd.), Valifast Colors dyes (Orient Chemical Industry Co., Ltd.), Savinyl, Sandoplast, Polysynthren, and Lanasyn dyes (Clariant Japan Co., Ltd.), Aizen Spilon dyes (Hodogaya Chemical Co., Ltd.), functional pigments (Yamada Chemical Co., Ltd.), Plast Color dyes, and Oil Color dyes (Arimoto Chemical Industry Co., Ltd.). These dyes can be used alone or in combination.

[0183] The pigment used as component (C-1) is preferably a pigment with high heat resistance in terms of color fading during curing. Specific examples, expressed in terms of Color Index (CI) numbers, include yellow pigments such as Pigment Yellow 83, 117, 129, 138, 139, 150, and 180. Examples of orange pigments include Pigment Orange 38, 43, 64, 71, and 72. The content of component (C-1) is preferably 0.1 to 100 parts by mass, more preferably 0.2 to 50 parts by mass, per 100 parts by mass of resin (A). By ensuring that the content of component (C-1) is 0.1 parts by mass or more, light of the corresponding wavelength can be absorbed. By ensuring that the content is 100 parts by mass or less, light transmittance, sensitivity, and resolution can all be achieved.

[0184] In the present invention, it is preferable that the resin composition containing the (A) resin further contains a (C) colorant, and that the (C) colorant contains (C-2) a colorant having an absorption maximum in the wavelength range of more than 490 nm and not more than 580 nm.

[0185] In the present invention, it is preferable that the resin composition containing the resin (A) further contains a colorant (C), and the colorant (C) contains a colorant (C-3) having an absorption maximum in the wavelength range of more than 580 nm and not more than 800 nm. In the present invention, it is also preferred that the component (C) further contains, in addition to the component (C-1), (C-2) a colorant having an absorption maximum in the wavelength range of more than 490 nm to 580 nm, and (C-3) a colorant having an absorption maximum in the wavelength range of more than 580 nm to 800 nm.

[0186] By containing the components (C-2) and (C-3) in addition to the component (C-1), in addition to the hiding power, the blackening reduces the reflection of external light and improves the contrast, thereby improving the visibility, which is preferable. Like the (C-1) component, the (C-2) and (C-3) components preferably have high solvent solubility, heat resistance, and transmittance at wavelengths of 350 nm to 390 nm, and preferably use at least one of dyes and organic pigments, with dyes being more preferred. This is preferred because mixing the (C-1) component with the (C-2) and (C-3) components not only produces a black color but also enhances the sensitivity and resolution of the resin film.

[0187] Examples of the skeleton structure of the dye that can be preferably used as the components (C-2) and (C-3) include, but are not limited to, triphenylmethane-based dyes, anthraquinone-based dyes, etc. These dyes may be used alone or as metal-containing complex salts. Specific examples of dyes that can be used include, but are not limited to, Sumilan and Lanyl dyes (Sumitomo Chemical Co., Ltd.), Orasol, Oracet, Filamid, and Irgasperse dyes (Ciba Specialty Chemicals Co., Ltd.), Zapon, Neozapon, Neptune, and Acidol dyes (BASF Ltd.), Kayaset and Kayakalan dyes (Nippon Kayaku Co., Ltd.), Valifast Colors dyes (Orient Chemical Industry Co., Ltd.), Savinyl, Sandoplast, Polysynthren, and Lanasyn dyes (Clariant Japan Co., Ltd.), Aizen Spilon dyes (Hodogaya Chemical Co., Ltd.), functional pigments (Yamada Chemical Co., Ltd.), Plast Color dyes, and Oil Color dyes (Arimoto Chemical Industry Co., Ltd.). These dyes can be used alone or in combination.

[0188] Specific examples of organic pigments that can be preferably used as component (C-2) are shown by Color Index (CI) numbers. Examples of red pigments include Pigment Red 48:1, 122, 168, 177, 202, 206, 207, 209, 224, 242, and 254. Examples of purple pigments that can be preferably used as component (C-2) include Pigment Violet 19, 23, 29, 32, 33, 36, 37, and 38. Examples of blue pigments that can be preferably used as component (C-3) include Pigment Blue 15 (15:3, 15:4, 15:6, etc.), 21, 22, 60, and 64. Examples of green pigments that can be preferably used as component (C-3) include Pigment Green 7, 10, 36, 47, and 58. Pigments other than these can also be used. Similarly to the above, pigments that have been surface-treated may be used if necessary.

[0189] The contents of the (C-2) and (C-3) components are each preferably 0.1 to 100 parts by mass, more preferably 0.2 to 50 parts by mass, per 100 parts by mass of the (A) resin. By ensuring that the content of the (C-1) component is 0.1 part by mass or more, it is possible to absorb light of the corresponding wavelength. Furthermore, by ensuring that the content is 100 parts by mass or less, it is possible to achieve both high light transmittance, high sensitivity, and high resolution.

[0190] Furthermore, from the viewpoints of storage stability and color fading during curing, the dyes used as the components (C-1), (C-2), and (C-3) are preferably dyes that are soluble in an organic solvent that dissolves the resin (A), are compatible with the resin, and have high heat resistance. Examples of the organic solvent include polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, N,N'-dimethylpropyleneurea, N,N-dimethylisobutyric acid amide, and methoxy-N,N-dimethylpropionamide; ethers such as tetrahydrofuran, dioxane, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, and diisobutyl ketone; esters such as ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, propylene glycol monomethyl ether acetate, and 3-methyl-3-methoxybutyl acetate; alcohols such as ethyl lactate, methyl lactate, diacetone alcohol, and 3-methyl-3-methoxybutanol; and aromatic hydrocarbons such as toluene and xylene. Furthermore, the heat resistance is preferably such that no change in the absorption spectrum is observed before and after heating at 250° C. for 1 hour in an atmosphere with an oxygen concentration of 100 ppm or less.

[0191] The organic pigment may be surface-treated, such as by rosin treatment, acidic group treatment, or basic group treatment, as needed. In addition, the organic pigment may be used in combination with a dispersant, if necessary. Examples of dispersants include cationic, anionic, nonionic, amphoteric, silicone, and fluorine-based surfactants.

[0192] In the present invention, it is preferable that the resin composition containing the (A) resin further contains a (C) colorant, and the (C) colorant contains a (C-4) black colorant (hereinafter, sometimes referred to as a (C-4) component).

[0193] When the component (C) contains the component (C-4), the transmittance of the cured film according to the present invention at a thickness of 1 μm can be set to 0.1% or more and 95% or less for light with a wavelength of 450 nm. The concealing properties of the cured film make it difficult to see the metal wiring from the outside, improving the design properties, and further increasing visibility by reducing external light reflection and improving contrast.

[0194] It is sufficient that at least one type of component (C-4) is contained. For example, a method using one type of inorganic black pigment, organic black pigment, or black dye, or a method using a combination of two or more types of inorganic black pigments, organic black pigments, or black dyes may be used.

[0195] Examples of inorganic black pigments include, but are not limited to, inorganic black pigments containing titanium atoms, inorganic black pigments containing zirconium atoms, amorphous carbon black, and carbon black. Amorphous carbon black, as used herein, refers to non-crystalline carbon black particles. Meanwhile, simply referring to carbon black, refers to crystalline carbon black particles that are generally well known for use as a colorant.

[0196] The inorganic black pigment containing titanium atoms means any one or more of titanium nitride represented by TiN, oxynitride titanium represented by TiNxOy (0 < x < 2.0, 0.1 < y < 2.0), titanium carbide represented by TiC, a solid solution of titanium nitride and titanium carbide, and a composite oxide or composite nitride of titanium and a metal other than titanium. Among them, either titanium nitride or oxynitride titanium is preferable in that it has high light-shielding properties in the visible light region and high light transmittance in the exposure process, and titanium nitride is more preferable in terms of low dielectric constant. As a production method of titanium nitride, a gas-phase reaction can be mentioned, and among them, titanium nitride synthesized by a thermal plasma method is preferable because it is easy to obtain particles with a small primary particle diameter and a sharp particle size distribution. In addition, in order to avoid an increase in the dielectric constant, the inorganic black pigment containing titanium atoms preferably has a lower content of titanium dioxide represented by TiO2, which is an inorganic white pigment, as an impurity, and it is more preferable not to contain it.

[0197] The inorganic black pigment containing zirconium atoms means any one or more of zirconium nitride represented by Zr3N4, zirconium nitride represented by ZrN, oxynitride zirconium represented by ZrOxNy (0 < x < 2.0, 0.1 < y < 2.0), and a composite oxide or composite nitride of zirconium and a metal other than zirconium. Among them, zirconium nitride represented by ZrN is preferable because it has high light transmittance in the exposure process and a low dielectric constant. As a production method, a gas-phase reaction can be mentioned, and among them, zirconium nitride synthesized by a thermal plasma method is preferable because it is easy to obtain particles with a small primary particle diameter and a sharp particle size distribution. In addition, in order to avoid an increase in the dielectric constant, the inorganic black pigment containing zirconium atoms preferably has a lower content of zirconium dioxide represented by ZrO2, which is an inorganic white pigment, as an impurity, and it is more preferable not to contain it.

[0198] The inorganic black pigment containing titanium atoms and the inorganic black pigment containing zirconium atoms may be subjected to a surface treatment to modify the pigment surface, if necessary. Examples of surface treatment methods include a method of introducing an organic group containing a silicon atom as a surface modification group through treatment with a silane coupling agent, or a method of coating part or all of the pigment surface with a coating material such as silica, metal oxide, and / or organic resin. Multiple surface treatments may also be combined. By applying these surface treatments, the long-term storage stability of the resin composition of the present invention may be improved. The inorganic black pigment containing zirconium atoms and the inorganic black pigment containing titanium atoms may form a single primary particle as a solid solution containing both.

[0199] Amorphous carbon black is a material with a diamond structure (SP 3 structure) and graphite structure (SP 2 This refers to amorphous carbon black consisting of a carbon black with a structure of SP. It corresponds to carbon classified as diamond-like carbon (DLC). Amorphous carbon black has higher insulating properties than crystalline carbon black, which will be described later, and can be suitably used as a colorant without surface treatment. The preferred manufacturing method is to vaporize a carbon source, cool the vaporized carbon vapor, resolidify it, then form it into flakes, and dry grind it to make them into fine particles. The structure of amorphous carbon black is SP 3 When the structure is contained in large amounts, the light blocking ability for visible light and near infrared rays is low, but the insulating property can be improved. 2 When the structure is contained in a large amount, the insulating property is low, but the light blocking property for visible light and near infrared rays can be improved. In other words, the properties inherent to the pigment can be controlled by the synthesis conditions. Among them, the photosensitive composition of the present invention contains SP 3 Structure and SP 2 For the total structure, SP 3 Amorphous carbon black having a structure content of 30 to 70 atom % can be preferably used. 3 Structure and SP 2 The proportions of the structure can be analyzed by X-ray photoelectron spectroscopy.

[0200] The total amount of the titanium-atom-containing inorganic black pigment, zirconia-atom-containing inorganic black pigment, and amorphous carbon is preferably 5.0 wt % or more of the total solid content of the photosensitive composition in the present invention to further improve near-infrared shading. Furthermore, to avoid an excessive increase in the dielectric constant, the total amount is preferably 35.0 wt % or less of the total solid content of the photosensitive composition. The term "total solid content" as used herein refers to the components of the photosensitive composition excluding the solvent.

[0201] Carbon blacks are classified by their manufacturing method, and include furnace black, thermal black, channel black, acetylene black, ketjen black, and lamp black. Among these, furnace black manufactured by the furnace method is preferred due to its excellent dispersibility and the ease of industrially controlling the acidity of the pigment surface and the particle size. From the viewpoint of improving insulation, the shorter the length of the structure in which the particles are tightly linked like beads, which is characteristic of carbon black, the more preferable. Furthermore, carbon blacks surface-modified with organic groups or coated with highly insulating coating materials are even more preferred. Such surface-modified carbon blacks may be commercially available, such as "TPK-1227," a carbon black surface-modified with acidic functional groups containing sulfur atoms, and "TPX-1409," a carbon black whose pigment surface is coated with silica (both manufactured by CABOT).

[0202] The total amount of carbon black is preferably 5.0% by weight or more of the total solid content of the resin composition in the present invention in order to further improve the near-infrared ray shielding property, and is preferably 10.0% by weight or less of the total solid content of the resin composition in order to avoid an excessive increase in the dielectric constant.

[0203] A mixture of multiple materials may be used so that the cured film has the desired optical properties. For example, by using zirconium nitride, which exhibits a black color with a strong purplish tint, and amorphous carbon, which exhibits a black color with a strong yellowish tint, to achieve a color tone, the reflected color of the cured film can be made neutral black with low saturation.

[0204] The average primary particle size of the inorganic black pigment is preferably 5 nm or more, more preferably 10 nm or more, from the viewpoint of improving dispersibility and storage stability after dispersion. On the other hand, from the viewpoint of obtaining high flexibility, it is preferably 150 nm or less, more preferably 100 nm or less. The average primary particle size here refers to the number-average primary particle size calculated by a particle size measurement method using an image analysis particle size distribution analyzer. Images can be taken using a transmission electron microscope (TEM), and the average primary particle size can be calculated at a magnification of 50,000x. If the (C-4) component is not spherical, the average of its major and minor diameters is taken as the primary particle size. Image analysis was performed using Mac-View, an image analysis particle size distribution software manufactured by Mountech Co., Ltd. If it is necessary to reduce the average primary particle size or to grind coarse particles to achieve a sharp particle size distribution, dry milling may be performed. For dry milling, a hammer mill, ball mill, or the like may be used. Furthermore, when there is a limit to what can be achieved by dry pulverization due to reasons such as excessively high hardness of the pigment, it is desirable to remove the coarse particles by classification without crushing.

[0205] Organic black pigments include benzodifuranone-based black pigments, perylene-based black pigments, azo-based black pigments, and their isomers. The term "isomer" here also includes tautomers. The isomers may be contained as a mixture of multiple pigment powders, or may be contained as a mixed crystal in the formation of a single primary particle. Generally, organic pigments have very poor light-blocking properties in the near-infrared region, but have the advantage of a low dielectric constant. Therefore, in the resin composition containing the (A) resin of the present invention, organic pigments can be effectively used as a component that imparts light-blocking properties only in the visible light region while avoiding an increase in the dielectric constant.

[0206] Examples of benzodifuranone-based black pigments include, but are not limited to, BASF's "Irgaphor (registered trademark)" Black S0100. Dispersibility can be improved by partially mixing a benzodifuranone-based black pigment having a substituent such as SO3H, SO3-, or COOH as a dispersing aid and then performing a wet dispersion treatment.

[0207] Examples of perylene-based black pigments include, in terms of Color Index (CI) numbers, CI Pigment Black 31 and 32, such as FK4280 manufactured by BASF, but are not limited thereto.

[0208] The resin composition containing the resin (A) of the present invention may further contain a dispersant. A dispersant is defined as a compound having both pigment-affinity groups that chemically bond or adsorb to the pigment surface and solvent-philic polymer chains or groups. The dispersant's mechanism of action involves a combination of acid-base interactions, hydrogen bonding, van der Waals forces, and other factors. During the wet media dispersion process performed to prepare the pigment dispersion (described below), the dispersant enhances the wettability of the organic pigment surface to the dispersion medium and enhances the steric and / or electrostatic repulsion between the organic pigment particles due to the polymer chains, thereby promoting pigment micro-particle size and improving dispersion stability. This promotion of micro-particle size and improved dispersion stability further improves flexibility.

[0209] Dispersants having a basic adsorption group, dispersants having an acidic group, and nonionic dispersants can be preferably used. Examples of dispersants having a basic adsorption group include DisperBYK-142, 145, 164, 167, 182, 187, 2001, 2008, 2009, 2010, 2013, 2020, 2025, 9076, 9077, BYK-LP N6919, and BYK-LP N21116, BYK-JET9152 (all manufactured by BYK-Chemie), Solsperse (registered trademark) 9000, 11200, 13650, 20000, 24000, 24000SC, 24000GR, 32000, 32500, 32550, 326000, 33000, 34750, 35100, 35200, 37500, 39000, 56000, 76500 (all manufactured by Lubrizol), and Efka-PX4310, 4320, 4710 (all manufactured by BASF). Examples of dispersants having an acidic group include Tego dispers (registered trademark) 655 (manufactured by Evonik) and DisperBYK-102, 118, 174, and 2096 (all manufactured by BYK-Chemie). Examples of nonionic dispersants include SOLSPERSE (registered trademark) 54000 (manufactured by Lubrizol) and Tego dispers (registered trademark) 650, 652, and 740W (all manufactured by Evonik). Taking into consideration the surface properties and average primary particle size specific to the pigment, these dispersants may be used alone or in combination so as to obtain the average dispersed particle size described below.

[0210] The content of the dispersant is preferably 10 parts by weight or more, and more preferably 20 parts by weight or more, per 100 parts by weight of the total pigment, in order to ensure sufficient deaggregation in the wet media dispersion treatment described below and to suppress reagglomeration after the dispersion treatment. On the other hand, in order to ensure a sufficient content of components other than the dispersant, the content is preferably 100 parts by weight or less, and more preferably 60 parts by weight or less.

[0211] The resin composition containing the (A) resin may contain, as necessary, other components such as a thermal crosslinker, a radically polymerizable compound, an antioxidant, a solvent, a compound having a phenolic hydroxyl group, an adhesion improver, an adhesion promoter, or a surfactant.

[0212] 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 colorant (C), the thermal crosslinking agent, the radical polymerizable compound, the antioxidant, the solvent, the compound having a phenolic hydroxyl group, the adhesion improver, the adhesiveness improver, the surfactant, and the like.

[0213] The dissolution method may be a known method such as heating or stirring.

[0214] The viscosity of the resin composition is preferably 2 to 5,000 mPa·s. By adjusting the solid content so that the viscosity is 2 mPa·s or higher, it is easy to obtain the desired film thickness. On the other hand, if the viscosity is 5,000 mPa·s or lower, 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 to 5 to 60 mass%. Here, the solid content concentration refers to the components other than the solvent.

[0215] 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.

[0216] When forming a cured film by curing a resin composition containing (A) resin, a resin sheet may be formed from the resin composition containing (A) resin, and then the resin sheet may be cured to form a film.

[0217] 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.

[0218] A film such as polyethylene terephthalate (PET) can be used as the substrate to which the resin composition is applied. When a resin sheet is used by laminating it 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.

[0219] Next, a method for manufacturing the display device will be described.

[0220] The method for manufacturing a display device of the present invention is a method for manufacturing a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, 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 on the supporting substrate and the light-emitting elements; (D3) exposing and developing the resin film to form a pattern of a plurality of penetrating openings in the resin film; (D6) curing the resin film to form the cured film having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 μm; and (D5) forming the metal wiring on at least a portion of the surface of the cured film and in the opening pattern of the cured film.

[0221] FIG. 7 shows cross-sectional views of an example of a manufacturing process of a display device having a plurality of light-emitting elements according to the present invention.

[0222] 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 the applied resin composition, and the term "cured film" refers to a resin film or a film obtained by curing a resin sheet.

[0223] In FIG. 7a, step (D1) is a step of placing a light-emitting element 2 having a pair of electrode terminals 6 on a support substrate 18. The support substrate may be, but is not limited to, a glass substrate, a silicon substrate, ceramics, gallium arsenide, an organic circuit substrate, an inorganic circuit substrate, or any of these substrates on which a circuit component material is disposed. A temporary adhesive material may be disposed on the glass substrate or silicon substrate. A TFT array substrate may also be used. The support substrate may be removed during the process, and after removal, another opposing substrate may be disposed.

[0224] Next, step (D2) is a step of forming a resin film 19 by applying or laminating a resin composition containing (A) resin or a resin sheet formed from a resin composition containing (A) resin onto the support substrate 18 and the light-emitting element 2, as shown in Figure 7b.

[0225] 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, metal wiring, or partition wall.

[0226] Examples of coating methods 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 is 0.1 to 150 μm.

[0227] Prior to coating, the support substrate to which the resin composition containing the (A) resin is to be applied may be pretreated with the aforementioned adhesion promoter. 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 prepared by dissolving 0.5 to 20% by mass of the adhesion promoter 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 carried out, if necessary. Furthermore, a subsequent heat treatment at 50°C to 280°C may be carried out to promote the reaction between the substrate and the adhesion promoter.

[0228] Next, the coated film of the resin composition containing the (A) resin is dried to obtain a resin film 19. 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 one minute to several hours.

[0229] 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 19. 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.

[0230] 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, if 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 the pattern formed in the exposure and development steps.

[0231] Next, in step (D3), as shown in FIG. 7c, a penetrating opening pattern 12 corresponding to the shape of the metal wiring 4 is formed in the resin film 19 using a photolithography process.

[0232] (A) A resin composition or resin sheet containing the resin can be microfabricated, allowing for high-density arrangement of light-emitting elements.

[0233] 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, and X-rays. 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.

[0234] The exposed photosensitive resin film 19 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 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.

[0235] Next, in step (D6), as shown in FIG. 7c, the resin film 19 is cured to form a cured film 3 having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a standard thickness of 5 μm.

[0236] Alternatively, the process may be a step (D4) of curing the resin film 19 to form a cured film 3 having a transmittance of 0.1% or more and 79% or less at a wavelength of 450 nm when the thickness is 5 μm, or a step (D7) of curing the resin film 19 to form a cured film 3 having a transmittance of 0.1% or more and 25% or less at a wavelength of 450 nm when the thickness is 1 μm.

[0237] The resin film 19 is heated to promote a ring-closing reaction or a thermal crosslinking reaction, yielding a cured film 3. The cured film 3 has improved heat resistance and chemical resistance due to crosslinking between (A) resins or (B) photosensitizers or thermal crosslinking agents. This heat treatment may be carried out by gradually increasing the temperature or by continuously increasing the temperature. The heat treatment is preferably carried out for 5 minutes to 5 hours. One example is a 30-minute heat treatment at 110°C followed by a further 60-minute heat treatment at 230°C. The heat treatment conditions are preferably 140°C or higher and 400°C or lower. To promote the thermal crosslinking reaction, the heat treatment temperature is preferably 140°C or higher, more preferably 160°C or higher. To provide an excellent cured film and improve the reliability of display devices, the heat treatment temperature is preferably 300°C or lower, more preferably 250°C or lower.

[0238] Heating may be carried out in an air atmosphere, or in order to prevent discoloration of component (C), in an atmosphere with a low oxygen concentration, preferably 1000 ppm or less, more preferably 300 ppm or less, and even more preferably 100 ppm or less.

[0239] 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.

[0240] Fig. 17 shows a front cross-sectional view of the opening pattern of the cured film. In Fig. 17, the angle of the inclined side 28 of the opening pattern formed in the cured film 3 is 29. The inclined side is a straight line connecting the opening pattern at position 31, which is halfway in the thickness direction of the cured film 3, and the opening pattern at the bottom.

[0241] Next, in FIG. 7c, in order to improve adhesion between the cured film 3 and the metal wiring 4, a barrier metal such as titanium is sputtered on the cured film 3, and a copper seed (seed layer) is further formed on top of that by sputtering.

[0242] Next, in step (D5), as shown in Fig. 7d, a photoresist layer (not shown) is formed, and then metal wiring 4 made of copper or the like is formed by plating or the like on the opening pattern 12 of the cured film 3 and on part of the surface of the cured film 3 to electrically connect to a pair of electrode terminals 6 of the light-emitting element 2. Thereafter, unnecessary photoresist, seed layer, and barrier metal are removed. This allows the cured film 3 to conceal the metal wiring 4, making it difficult to see the metal wiring 4 from the outside, thereby improving the design. Furthermore, visibility can be improved by reducing external light reflection and improving contrast.

[0243] The method for producing a display device of the present invention preferably includes a step of repeating the steps (D2), (D3), (D6), and (D5) multiple times to form multiple layers of the cured film having the metal wiring therein.

[0244] As shown in FIGS. 7e to 7f, the cured film 3 and the metal wiring 4 can be formed by repeating the same method again to form a cured film 3 consisting of two or more layers.

[0245] This allows for the arrangement of multiple light-emitting elements by forming multiple layers of cured films having metal wiring within the cured films, and also makes it possible to suppress wiring defects such as short circuits caused by a lower package height or shorter wiring distances, reduce loss, and improve high-speed response.

[0246] Thereafter, as shown in FIG. 7g, a barrier metal 9 is formed by sputtering in the opening pattern 12 of the cured film 3 to form solder bumps 10. The barrier metal 9 may or may not be present. The solder bumps 10 are electrically connected to a light-emitting element drive substrate 7 having a drive element such as a driver IC.

[0247] A plurality of driving elements 8 may be used for each light-emitting element 2 or for one unit of light-emitting elements 2 consisting of red, blue, and green, depending on the function, and for example, a plurality of driving elements may be disposed near the light-emitting element during the process of Fig. 7. In this case, the driving elements are electrically connected to the light-emitting element 2 via metal wiring 4 extending into the cured film 3.

[0248] 7h, the metal wiring 4 is electrically connected to a light-emitting element driving substrate 7 having driving elements 8 such as a driver IC via solder bumps 10, the support substrate 18 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 metal wiring 4 may include electrodes.

[0249] This allows the cured film 3 to conceal the metal wiring 4, making it difficult to see the metal wiring 4 from the outside, thereby improving the design. Furthermore, visibility can be improved by reducing external light reflection and improving contrast.

[0250] The metal wiring 4 may be replaced with a conductive film 26. Figure 25 shows a process in which a conductive film 26 is used instead of the metal wiring 4.

[0251] The method for producing a display device of the present invention preferably includes, before the step (D1), a step (D8) of providing a partition wall having a thickness equal to or greater than the thickness of the light-emitting element.

[0252] An example of step (D8) is shown in Figure 18. Figure 18a shows step (D8) of providing partition walls 15 having a thickness equal to or greater than that of the light-emitting element 2 on a support substrate, and the following Figure 18b shows 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. Figure 18c shows a step of disposing a resin film 19, similar to step (D2) shown in Figure 7b, while leaving the partition walls 15 in place. The subsequent steps are carried out as shown in Figure 7. The partition walls may be made of (A) resin, 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.

[0253] 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) in which a driving element and a substrate are provided, the driving element is connected to the light-emitting element through metal wiring, and at least a portion of the metal wiring extends to the side of the substrate. An example of step (D9) is shown in Figure 7. Figure 7h shows step (D9) having a driving element and a substrate, and the driving element is connected to the light-emitting element through metal wiring. As shown in Figure 7h, the driving element is connected to the light-emitting element 2 through metal wiring 4 and 4c, and part of the metal wiring 4c extends to the side 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.

[0254] 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.

[0255] The metal wiring 4c can be made of, for example, gold, silver, copper, aluminum, nickel, titanium, tungsten, aluminum, tin, chromium, or an alloy containing any of these. If wiring already exists on the substrate or light-emitting element driving substrate 7, that wiring may be used.

[0256] In the method for manufacturing a display device of the present invention, the metal wiring may be a conductive film (D10).

[0257] An example of step (D10) is shown in Fig. 19. In Fig. 19h, the driving element is connected to the light emitting element 2 through the metal wiring 4 and the conductive film 26, and part of the conductive film 26 extends to the side surface of the light emitting element driving substrate 7.

[0258] 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.

[0259] The conductive film 26 is preferably a compound 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, or a photosensitive conductive paste containing organic matter and conductive particles.

[0260] The method for producing a display device of the present invention preferably further comprises the step (D11) of providing a light-shielding layer between the plurality of light-emitting elements. An example of step (D11) is shown in Fig. 20. Fig. 20a shows step (D11) of providing a light-shielding layer 27 between a plurality of light-emitting elements 2. The light-shielding layer 27 may be formed before or after the light-emitting elements 2 are formed.

[0261] The light-shielding layer 27 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 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 fine metal 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. Dyes may also be used. Two or more colorants may be used.

[0262] The resin composition containing the (A) resin and the (E) colorant may be given photosensitivity, and a (B) photosensitizer described below may be used.

[0263] The light-shielding layer may be formed using a photolithography process if it is photosensitive, or may be formed by forming a photoresist on the light-shielding layer, followed by a photolithography process or an etching process, or by an etching process using a mask. A patterned colored film can be obtained by subjecting the resulting pattern to a heat treatment (post-baking). The heat treatment may be carried out 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 stepwise.

[0264] The method for manufacturing a display device of the present invention is a method for manufacturing a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, and includes the steps of: (E1) arranging metal pads on a support substrate; (E2) forming a resin film made of a resin composition containing (A) resin on the support substrate and the metal pads; (E3) exposing and developing the resin film to form a pattern of a plurality of through-holes in the resin film; (E10) curing the resin film to form the cured film having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 μm; (E5) forming the metal 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 metal wiring.

[0265] Figure 8 shows cross-sectional views of the manufacturing process of another embodiment of the display device 1 of the present invention. Since the steps overlap with those in Figure 7, specifically Figures 8b to 8e overlap with Figures 7b to 7f, their explanations are omitted.

[0266] Step (E1) is a step of arranging metal pads 17 on a support substrate 18, as shown in FIG. 8a.

[0267] The metal pad may be made of copper or aluminum.

[0268] Next, in step (E2), as shown in FIG. 8b, a resin composition or a resin sheet containing (A) resin is applied or laminated onto the support substrate 18 and the metal pads 17 to form a resin film 19.

[0269] Here, "on the support substrate and on the metal pad" does not only mean the surface of the support substrate or the surface of the metal pad, but also means the upper side of the support substrate or the metal pad, 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, metal wiring, or partition wall.

[0270] Next, in the step (E3), as shown in FIG. 8c, a plurality of penetrating opening patterns 12 are formed in the resin film 19 using a photolithography process.

[0271] Next, in step (E10), as shown in FIG. 8c, the resin film 19 is cured to form a cured film 3 having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 μm. Alternatively, the process may be a step (E4) of curing the resin film 19 to form a cured film 3 having a transmittance of 0.1% or more and 79% or less at a wavelength of 450 nm when the thickness is 5 μm, or a step (E8) of curing the resin film 19 to form a cured film 3 having a transmittance of 0.1% or more and 25% or less at a wavelength of 450 nm when the thickness is 1 μm.

[0272] Next, in FIG. 8c, in order to improve adhesion between the cured film 3 and the metal wiring 4, a barrier metal such as titanium is sputtered on the cured film 3, and a copper seed (seed layer) is further formed on top of that by sputtering.

[0273] Next, in step (E5), as shown in Fig. 8d, a photoresist layer (not shown) is formed, and then metal wiring 4 made of copper or the like is formed by plating or the like on the opening pattern 12 of the cured film 3 and on part of the surface of the cured film 3. Thereafter, unnecessary photoresist, seed layer, and barrier metal are removed.

[0274] The method for manufacturing a display device of the present invention preferably includes a step of repeating the steps (E2), (E3), (E10), and (E5) multiple times to form multiple layers of the cured film having the metal wiring therein.

[0275] As shown in FIGS. 8b to 8d, the cured film 3 and the metal wiring 4 can be formed by repeating the same method again to form a cured film 3 consisting of two or more layers as shown in FIG. 8e.

[0276] Next, in step (E6), as shown in Fig. 8f, the light-emitting element 2 is disposed on the cured film 3 so as to maintain electrical connection with the metal wiring 4. The metal wiring 4 of the electrode terminal 6 of the light-emitting element 2 may be connected directly or via, for example, a solder ball. 8g, it is preferable to have a step (E7) of forming a cured film 21 on the cured film 3 and the light-emitting element 2. It is preferable to form the cured film 21 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 21. The cured film 21 may also be made of a material other than the resin composition containing the (A) resin, and known materials such as epoxy resin, silicone resin, and fluororesin may also be used.

[0277] The curing conditions vary depending on the type of resin, but examples include 80°C to 230°C and 15 minutes to 5 hours.

[0278] This is intended to protect and flatten the light emitting element by forming a cured film on the light emitting element.

[0279] 8h, the opposing substrate 5 is bonded to the cured film 21 using an adhesive or the like. The support substrate 18 is then peeled off, and a barrier metal 9 and bumps 10 are formed, which are then electrically connected via the solder bumps 10 to the light-emitting element drive substrate 7 to which drive elements 8 such as driver ICs are attached.

[0280] The driving elements 8 are electrically connected to the light-emitting elements 2 via metal wiring 4 extending into the cured film 3, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. The metal wiring 4 may include electrodes.

[0281] This allows the cured film 3 to conceal the metal wiring 4, making it difficult to see the metal wiring 4 from the outside, thereby improving the design. Furthermore, visibility can be improved by reducing external light reflection and improving contrast.

[0282] The metal wiring 4 may be replaced with a conductive film 26. Figure 26 shows a process in which a conductive film 26 is used instead of the metal wiring 4.

[0283] 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.

[0284] An example of step (E9) is shown in Figure 9. Figure 9f shows step (E9) of forming multiple layers of the cured film 3 shown in Figure 8e and then providing partition walls 15. Thereafter, as shown in Figure 9g, light-emitting elements 2 are provided between the partition walls 15. Next, as shown in Figure 9h, an opposing substrate 5 is attached to the upper part of the partition walls 15 and the light-emitting elements 2, and the support substrate 18 is peeled off. A barrier metal 9 and bumps 10 are formed, and the light-emitting elements are electrically connected via the solder bumps 10 to a light-emitting element drive substrate 7 having drive elements 8 such as a driver IC.

[0285] 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 metal wiring, and at least a portion of the metal wiring extending to the side of the substrate.

[0286] An example of step (E11) is shown in Figure 8. Figure 8h 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 metal wiring. As shown in Figure 8h, the driving element is connected to the light-emitting element 2 through metal wiring 4 and 4c, and part of the metal 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.

[0287] 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.

[0288] The metal wiring 4c can be made of, for example, gold, silver, copper, aluminum, nickel, titanium, tungsten, aluminum, tin, chromium, or an alloy containing any of these. If wiring already exists on the substrate or light-emitting element driving substrate 7, that wiring may be used.

[0289] In the method for manufacturing a display device, the metal wiring may be a conductive film (E12). An example of step (E12) is shown in Figure 21. In Figure 21h, the driving element is connected to the light-emitting element 2 through the metal wiring 4 and the conductive layer 26, and part of the metal wiring 4c and the conductive layer 26 extends to the side surface of the light-emitting element driving substrate 7.

[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 conductive film 26 is made of a compound 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. or A photosensitive conductive paste containing an organic substance and conductive particles is preferred.

[0292] 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 a plurality of light-emitting elements, and includes the steps of: (F1) forming a resin film made of a resin composition containing (A) resin on a substrate or the like; (F2) forming a pattern of a plurality of through-holes in the resin film by exposing and developing the resin film; (F3) curing the resin film to form the cured film having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 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.

[0293] FIG. 22 shows cross-sectional views of the manufacturing process of another embodiment of the display device 1 of the present invention.

[0294] Step (F1) is a step of forming a resin film made of a resin composition containing the (A) resin on a substrate, etc., as shown in Fig. 22a. 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.

[0295] The substrate can be a light emitting element driving substrate 7. Figure 22a shows an example of a TFT array substrate in which TFTs 22, insulating films 23, and metal wiring 4 are arranged on a glass substrate.

[0296] Examples of the metal wiring 4 include gold, silver, copper, aluminum, nickel, titanium, molybdenum, and alloys containing these. 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.

[0297] Next, in the step (F2), as shown in FIG. 22a, a pattern of a plurality of penetrating openings is formed in the resin film using a photolithography process.

[0298] Next, as shown in FIG. 22a, step (F3) is a step of forming a cured film 3 by curing the resin film, in which the transmittance of light with a wavelength of 450 nm at a thickness of 1 μm is 0.1% or more and 95% or less.

[0299] Next, in step (F4), as shown in Fig. 22b, 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 24 is formed on a portion of the surface of the cured film 3 by, for example, a sputtering method. Thereafter, unnecessary photoresist is removed.

[0300] Examples of wiring include metal wiring, 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 wiring may also be used.

[0301] The method for manufacturing 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.

[0302] By repeating the same method again, the cured film 3 can be formed into a cured film 3 consisting of two or more layers as shown in FIG. 22c.

[0303] Next, in step (F5), as shown in Fig. 22d, the light-emitting element 2 is disposed on the cured film 3 so as to maintain electrical connection with the wiring 24. The electrode terminal 6 of the light-emitting element 2 and the wiring 24 may be connected directly or via, for example, a solder ball.

[0304] Moreover, the partition wall 15 may be formed before or after the light emitting element 2 is disposed.

[0305] Thereafter, as shown in Fig. 22e, an opposing substrate 5 is attached using an adhesive or the like. A conductive film 26 is formed, and the driving elements 8 such as a driver IC are electrically connected to the light-emitting elements 2 through the conductive film 26 via the metal wiring 4 and wiring 24 extending into the cured film 3, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. The wiring 24 also includes electrodes.

[0306] This allows the cured film to ensure electrical insulation of the wiring, and by extending the wiring through the cured film, a pair of electrode terminals of the light-emitting element can be electrically connected to the driving element, thereby controlling the light-emitting operation. Furthermore, the cured film conceals the metal wiring, making it difficult to see the metal wiring from the outside, thereby improving the design. Furthermore, visibility can be improved by reducing external light reflection and improving contrast.

[0307] The display device of the present invention is suitably used for display devices such as various LED displays and various vehicle-mounted lamps. [Example]

[0308] The present invention will be described below with reference to examples, but the present invention is not limited to these examples. 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.

[0309] <Method for evaluating the light transmittance of a cured film> A varnish composed of the resin composition was spin-coated onto a 5 cm square glass substrate to a film thickness of 5.0 μm after heat treatment and prebaked at 120°C for 3 minutes. Then, 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. The temperature was then raised at a rate of 3.5°C / min to a heating temperature of 230°C, and then heat-treated at the elevated temperature for 1 hour. The coating film was dried and heat-treated to obtain a cured film. The thickness of the coating film after prebaking 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. The thickness of the cured film was measured with a refractive index of 1.629.

[0310] 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.) If the film thickness of the heat-resistant resin film after the heat treatment was not 5 μm, the measured transmittance spectrum was converted into a film thickness of 5 μm according to Lambert's law.

[0311] <Method for evaluating the concealment of metal wiring by cured film> The concealment of metal wiring by the cured film was evaluated using the display devices described in the following Examples and Comparative Examples. A microscope was used for the measurement. Whether the metal was concealed was evaluated visually using the microscope. Display devices in which the metal wiring was concealed by the cured film were rated as good (2), and display devices in which the metal wiring could be clearly seen by visual inspection through the cured film were rated as bad (1).

[0312] <Evaluation of opening pattern shape of cured film made of resin composition> The varnish was prepared and applied to an 8-inch silicon wafer by spin coating using a coating and developing system ACT-8 (Tokyo Electron Ltd.) so that the film thickness after heating would be 5 μm. The wafer was then prebaked to produce a prebaked film. The prebaking was carried out at 120°C for 3 minutes. The wafer was then prebaked using an i-line stepper (Nikon Corporation, NSR-2205i14) at 50 to 1000 mJ / cm. 2 The exposure was performed with an exposure dose of 1000 u / s. 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. The film was then rinsed with pure water and shaken dry to obtain a patterned film. Alternatively, the film was developed using cyclopentanone and shaken dry to obtain a patterned film. In the case of non-photosensitive materials, a photoresist was formed before exposure, followed by exposure and development, and 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.

[0313] After development, the pattern-forming film was cured by heating the film in an inert oven CLH-21CD-S (Koyo Thermo Systems Co., Ltd.) from 50°C to 100°C at a rate of 3.5°C / min under a nitrogen stream with an oxygen concentration of 20 ppm or less, followed by heat treatment at 100°C for 30 minutes. The film was then heated to 230°C at a rate of 3.5°C / min, followed by heat treatment for 1 hour, to cure the pattern-forming film and obtain a cured film.

[0314] When the temperature dropped below 50°C, the wafer was removed, and then cleaved to observe and measure the cross-sectional shape of the 5-30 μm circular pattern using a scanning electron microscope S-4800 (Hitachi High-Tech). The angle of the slanted side was determined by connecting the opening pattern at half the thickness of the cured film with the opening pattern at the bottom.

[0315] As a result, the angle of the inclined side was rated as Level A if it was between 50° and 80°, Level B if it was between 40° and 50° or between 80° and 85°, and Level C if it was less than 40° or more than 85°.

[0316] <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., hereafter 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 cooled to -15°C. A solution of 20.4 g (0.11 mol) of 3-nitrobenzoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) dissolved in 100 mL of acetone was added dropwise to the solution. After the addition was complete, 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.

[0317] 30 g of the resulting white solid was placed in a 300 mL stainless steel autoclave and dispersed in 250 mL of methyl cellosolve, followed by the addition of 2 g of 5% palladium-carbon (Wako Pure Chemical Industries, Ltd.). Hydrogen was introduced into the autoclave using a balloon, and the 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:

[0318] [ka]

[0319] <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 (HUNTSMAN) 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 reacted at 85 °C for 1 hour. After the reaction was completed, 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 stirred at room temperature for 1 hour. After 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).

[0320] <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 5-norbornene-2,3-dicarboxylic anhydride was added as an end-capping agent 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 along with 87 g of NMP, and the mixture was stirred at room temperature for 1 hour. After stirring, the solution was poured into 3 L of water to obtain a white precipitate, which was collected by filtration, washed three times with water, and then dried in a forced air dryer at 50°C for three days to obtain a powder of polybenzoxazole precursor (A-2).

[0321] <Synthesis Example 4: Synthesis of Polyimide Precursor (A-3)> Under a dry nitrogen stream, 51.9 g (0.086 mol) of the hydroxyl-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 and 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 along with 10 g of NMP, and the mixture was allowed to react at 40°C for 1 hour. Subsequently, a solution of 7.1 g (0.06 mol) of dimethylformamide dimethyl acetal (manufactured by Mitsubishi Rayon Co., Ltd., hereafter referred to as DFA) diluted with 5 g of NMP was added dropwise. Stirring was continued at 40°C for 2 hours. After stirring, the solution was poured into 2 L of water, and the polymer solid precipitate was collected by filtration. The polymer 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).

[0322] <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 a diamine containing propylene oxide and tetramethylene ether glycol (RT-1000, manufactured by HUNTSMAN Corp.), 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 and stirred at 40°C for 2 hours. 1.1 g (0.01 mol) of 3-aminophenol (as an end-capping agent) was then added along with 10 g of NMP, and the mixture was allowed to react at 40°C for 1 hour. A solution of 6.0 g (0.05 mol) of DFA diluted with 5 g of NMP was then added dropwise. Stirring was continued at 40°C for 2 hours. After stirring, the solution was poured into 2 L of water, and the polymer solid precipitate was collected by filtration. The polymer 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).

[0323] <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. To this solution, 31.2 g (0.1 mol) of ODPA was added along 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. This 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 polyimide (A-5) powder.

[0324] <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 bisphenol fluorene epoxy resin and acrylic acid (manufactured by Nippon Steel Chemical Co., Ltd., product name "ASF-400" solution), 39.54 g (0.12 mol) of benzophenone tetracarboxylic 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 heated to 120-125°C, and then heated and stirred for 6 hours at 75-80°C. After that, 8.6 g of glycidyl methacrylate was added, and the mixture was stirred for a further 8 hours at 80°C to obtain a resin (A-6) having a skeleton structure in which two cyclic structures are bonded to the quaternary carbon atom constituting the cyclic structure.

[0325] <Synthesis Example 8: Synthesis of phenolic resin (A-7)> Under a dry nitrogen stream, 108.1 g (1.0 mol) of m-cresol, 34.0 g (0.32 mol) of benzaldehyde, 90.4 g (0.74 mol) of salicylaldehyde, 200 g of ethanol, and 8.6 g (0.05 mol) of paratoluenesulfonic acid were charged into a reaction vessel and reacted for 18 hours under reflux at 65°C. After neutralizing the reaction system with caustic soda, methyl isobutyl ketone and water were added, and the mixture was washed five times with separation. The methyl isobutyl ketone was distilled off under reduced pressure at 100°C using an evaporator to obtain phenolic resin (A-7).

[0326] <Synthesis Example 9: Synthesis of Photosensitizer (Quinone Diazide 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 (Honshu Chemical Industry Co., Ltd., hereafter referred to as TrisP-PA) and 26.8 g (0.10 mol) of 5-naphthoquinone diazide sulfonic acid chloride (Toyo Gosei Co., Ltd., NAC-5) were dissolved in 450 g of γ-butyrolactone (hereafter also referred to as GBL) at room temperature. To this solution, 12.7 g of triethylamine mixed with 50 g of γ-butyrolactone was added dropwise so that the system temperature did not exceed 35°C. After the 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. It was then washed twice with 2 L of water. This precipitate was dried in a vacuum dryer to obtain a quinone diazide compound (B-1) represented by the following formula.

[0327] [ka]

[0328] <Synthesis Example 10: Synthesis of Photosensitizer (Quinone Diazide 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-naphthoquinone diazide 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 to the solution, ensuring that the temperature in the system did not exceed 35°C. After the 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. It was then washed twice with 2 L of water. The precipitate was dried in a vacuum dryer to obtain quinone diazide compound (B-2) represented by the following formula:

[0329] [ka]

[0330] <Synthesis Example 11 Synthesis of Polyimide Precursor (A-8)> 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 and stirred at 40°C for 2 hours. 1.1 g (0.01 mol) of 3-aminophenol (Tokyo Chemical Industry Co., Ltd.) as an end-capping agent was then added along with 10 g of NMP, and the mixture was allowed to react at 40°C for 1 hour. Subsequently, a solution of 7.1 g (0.06 mol) of DFA diluted with 5 g of NMP was added dropwise. Stirring was continued at 40°C for 2 hours. After stirring, the solution was poured into 2 L of water, and the precipitated polymer solid was collected by filtration. The mixture was 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 polyimide precursor (A-8).

[0331] <Synthesis Example 12: Synthesis of Polyimide Precursor (A-9)> 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 subsided, the mixture was allowed to cool to room temperature and then allowed to stand for a further 16 hours.

[0332] Next, under ice cooling, a solution of 206.3 g (1.00 mol) of dicyclohexylcarbodiimide (DCC) 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 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 stirred for 1 hour. Then, 400 g of γ-butyrolactone was added. The precipitate that formed in the reaction mixture was removed by filtration to obtain a reaction solution.

[0333] The reaction mixture 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-9).

[0334] <Synthesis Example 13: Synthesis of acrylic resin (A-10)> A reaction vessel under a nitrogen atmosphere was charged with 150 g of dimethylaminomethanol (hereinafter referred to as "DMEA"; manufactured by Tokyo Chemical Industry Co., Ltd.) and heated to 80°C using an oil bath. 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 continued for an additional 6 hours at 80°C under a nitrogen atmosphere. Then, 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 the dropwise addition was completed, the addition reaction was continued for another 2 hours at 80°C under a nitrogen atmosphere. The resulting reaction solution was purified with methanol to remove unreacted impurities, and then vacuum dried for 24 hours to obtain Resin (A-12) with a copolymerization ratio (by mass): EA / 2-EHMA / St / GMA / AA = 20 / 40 / 20 / 5 / 15. The acid value of the resulting Resin (A-10) was 103 mgKOH / g.

[0335] <Synthesis Example 14: Synthesis of acrylic resin (A-11)> A methyl methacrylate / methacrylic acid / styrene copolymer (weight ratio 30 / 40 / 30) was synthesized by the method described in Example 1 of Japanese Patent No. 3120476. 40 parts by weight of glycidyl methacrylate was added to 100 parts by weight of the obtained copolymer, and the mixture was reprecipitated with purified water, filtered, and dried to obtain a resin (A-11) with a weight-average molecular weight of 15,000 and an acid value of 110 mgKOH / g.

[0336] <Preparation Example 1: Preparation of Photosensitive Conductive Paste 1> A 100 mL clean bottle was charged with 10.0 g of resin (A-10) 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).

[0337] 17.50 g of the resulting resin solution was mixed with 44.02 g of silver particles with an average particle size of 1.0 μm and 0.28 g of carbon black with 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 a scanning electron microscope (SEM) at a magnification of 10,000x 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.

[0338] <Preparation Example 2: Production of Colorant Dispersion Liquid (DC-1)> Zirconia compound particles Zr-1 (manufactured by Nisshin Engineering Inc.) produced by thermal plasma processing were used as the colorant. 200 g of Zr-1, 114 g of a 35 wt% solution of acrylic polymer (P-1) in propylene glycol monomethyl ether acetate (PGMEA), 625 g of "DISPERBYK®" LPN-2111 (a polymer dispersant containing tertiary amino groups and quaternary ammonium salts), and 661 g of PGMEA were charged into a tank and stirred for 20 minutes with a homomixer to obtain a preliminary dispersion. The resulting preliminary dispersion was fed into an Ultra Apex Mill (manufactured by Kotobuki Industries Co., Ltd.) equipped with a centrifugal separator filled with 75% by volume of 0.05 mm diameter zirconia beads and dispersed at a rotation speed of 8 m / s for 3 hours to obtain a colorant dispersion (DC-1) with a solids concentration of 25 wt% and a colorant / resin (weight ratio) of 80 / 20.

[0339] <Preparation Example 3: Preparation of Photosensitive Colored Resin Composition 1> To 283.1 g of colorant dispersion (DC-1), 184.4 g of PGMEA 35 wt% solution of resin (A-11), 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) and 3.8 g of "KAYACURE (registered trademark)" DETX-S (manufactured by Nippon Kayaku Co., Ltd.) as a photopolymerization initiator, 12.0 g of KBM5103 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an adhesion improver, 3 g of a PGMEA 10 wt% solution of silicone surfactant "BYK (registered trademark)" 333 (manufactured by BYK-Chemie Co., Ltd.) as a surfactant was dissolved in 456.1 g of PGMEA to obtain a photosensitive colored resin composition 1, with a total solids concentration of 20 wt%, and a colorant / resin (weight ratio) = 30 / 70.

[0340] <Preparation Example 4: Production of Colorant Dispersion Liquid (DC-2)> According to the method described in JP-A-2008-517330, the surface element composition of carbon black (CB-Bk1) whose surface was modified with sulfonic acid groups was (C: 88%, O: 7%, Na: 3%, S: 2%). In terms of the state of the S element, of the S2p peak components, 90% were components attributed to CS and SS, and 10% were components attributed to SO and SOx. The BET value was 54 m / g.

[0341] 200 g of this carbon black CB-Bk1, 94 g of a 40% by weight solution of acrylic resin (A-13) in propylene glycol monomethyl ether acetate, 31 g of a 40% by weight solution of polymer dispersant BYK Japan LPN21116, and 675 g of propylene glycol monomethyl ether acetate were charged into a tank and stirred for 1 hour using a homomixer (Tokushu Kika Co., Ltd.). The preliminary dispersion was then fed into an Ultra Apex Mill (Kotobuki Industries Co., Ltd.) equipped with a centrifugal separator filled to 70% with 0.05 mm diameter zirconia beads (Nikkato YTZ balls). The dispersion was dispersed at a rotation speed of 8 m / s for 2 hours to obtain colored dispersion DC-2 with a solids concentration of 25% by weight and a pigment / resin (mass ratio) of 80 / 20.

[0342] <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 PGMEA of resin (A-13), 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 having a total solids concentration of 25 mass%, and a colorant / resin (weight ratio) = 45 / 55.

[0343] Preparation Example 6: Preparation of Pigment Dispersion 1 (C-4-1) 57.7 g of "Solsperse®" 20000 (a polyether-based polymer resin dispersant having a tertiary amino group at the molecular end) was mixed with 750.0 g of PGMEA solvent and stirred for 10 minutes, after which 192.3 g of titanium nitride (average primary particle size 25 nm; in the table, "TiN") was added and stirred for 30 minutes, followed by wet media dispersion treatment using a horizontal bead mill and filtration (PP filter pore size 0.8 μm) to prepare pigment dispersion 1 (C-4-1). The average dispersed particle size of the titanium nitride contained in pigment dispersion 1 was 85 nm.

[0344] Preparation Example 7: Preparation of Pigment Dispersion Liquid 2 (C-4-2) Using CI Pigment Blue 60 (average primary particle diameter 60 nm), an organic blue pigment, CI Pigment Red 190 (average primary particle diameter 55 nm), an organic red pigment, and CI Pigment Yellow 192 (average primary particle diameter 40 nm), each pigment dispersion was prepared using the same procedure as in Preparation Example 1. The average dispersed particle diameter of the CI Pigment Blue 60 contained in the pigment dispersion was 162 nm, the average dispersed particle diameter of the CI Pigment Red 190 was 110 nm, and the average dispersed particle diameter of the CI Pigment Yellow 192 was 90 nm. 400.0 g of the organic blue pigment dispersion, 300.0 g of the organic red pigment dispersion, and 300.0 g of the organic yellow pigment dispersion were mixed and stirred for 10 minutes to prepare Pigment Dispersion 2 (C-4-2), a pseudo-black dispersion.

[0345] Preparation Example 6: Preparation of Pigment Dispersion 3 30.00 g of Solsperse (registered trademark) 20000 was mixed with 850.0 g of PGMEA and stirred for 10 minutes, after which 120.0 g of an organic black pigment, a benzodifuranone pigment (average primary particle diameter 50 nm; BASF "Irgaphor (registered trademark)" Black S0100), was added and stirred for 30 minutes. Pigment dispersion 3 (C-4-3) was then prepared using a horizontal bead mill in the same manner as in Preparation Example 3. The average dispersed particle diameter of the benzodifuranone pigment contained in pigment dispersion 3 was 120 nm.

[0346] The components (B-3), (C-1), (C-2), (C-3), (F-1), (F-2), other components, and solvents used in the examples and comparative examples are shown below. Component (B-3): Photopolymerization initiator NCI-831 (manufactured by ADEKA Corporation) (C-1) Colorant: Plast Yellow 8070 (maximum absorption wavelength: 460 nm) (manufactured by Arimoto Chemical Industry Co., Ltd.) (C-2) Colorant: Oil Scarlet 5206 (maximum absorption wavelength: 530 nm) (manufactured by Arimoto Chemical Industry Co., Ltd.) (C-3) Colorant: Plast Blue 8540 (maximum absorption wavelength: 660 nm) (manufactured by Arimoto Chemical Industry Co., Ltd.) Other ingredients: Radical polymerizable compounds: Component (F-1): Dipentaerythritol hexaacrylate (DPHA, manufactured by Kyoeisha Chemical Co., Ltd.) Thermal crosslinker: (G-1) Component: HMOM-TPHAP (manufactured by Honshu Chemical Industry Co., Ltd.) (G-2) Ingredient: YX-4000H (Mitsubishi Chemical Corporation) solvent: GBL: gamma-butyrolactone PGMEA: propylene glycol monomethyl ether acetate.

[0347] [ka]

[0348] Table 1 shows the formulation of a resin composition composed of (A) a resin, (B) a photosensitizer, and (C) a colorant. Resin composition 1-21 was prepared using the solvent shown in Table 1 to have a solids concentration of 40% by mass. Tables 2-1 and 2-2 show the resin compositions used in the examples, the light transmittance (%) of a cured film of the resin composition at a wavelength of 450 nm when the thickness of the cured film was 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, and the angle of the inclined sides of the opening pattern.

[0349] [Table 1]

[0350] [Table 2-1]

[0351] [Table 2-2]

[0352] Regarding the evaluation level (1), display devices in which the metal wiring was concealed by the cured film and the longest length of the opening pattern was 2 μm or less were classified as Level A, display devices in which the metal wiring was concealed by the cured film and the longest length of the opening pattern was 5 μm or less were classified as Level B, display devices in which the metal wiring was concealed by the cured film and the longest length of the opening pattern was 20 μm or less were classified as Level C, display devices in which the metal wiring was concealed by the cured film and the longest length of the opening pattern was greater than 20 μm were classified as Level D, and display devices in which the metal wiring could be clearly seen with the naked eye due to the cured film were classified as Level E.

[0353] 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°.

[0354] (Example 1) (Configuration of FIG. 7) An embodiment of the display device of the present invention will be described with reference to the cross-sectional views of the manufacturing process shown in FIG.

[0355] As shown in Figure 7a, a glass substrate was used as the support substrate 18. A temporary bonding material made of polyimide was placed on the glass substrate, and the LED 2, a light-emitting element, was placed on the support substrate 18 (corresponding to step (D1)). The LED 2 had a thickness of 7 μm, one side length of 30 μm, and the other side length of 50 μm.

[0356] Next, as shown in FIG. 7b, resin composition 1 described in Table 1 was applied onto support substrate 18 and light emitting element 2 so as to have a thickness of 10 μm after heat treatment, thereby forming resin film 19 (corresponding to step (D2)).

[0357] Next, as shown in FIG. 7c, the resin film 19 was irradiated with i-line (365 nm) light through a mask having a desired pattern. The exposed resin film 19 was developed using a 2.38 mass % tetramethylammonium (TMAH) aqueous solution to form a plurality of opening patterns 12 penetrating the resin film 19 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.

[0358] Next, the resin film 19 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 harden it, thereby forming a cured film 3 with a thickness of 10 μm (corresponding to step (D4)). The resin film 19 hardens as it is and becomes the cured film 3.

[0359] Next, as shown in Figure 7d, a titanium barrier metal was sputtered onto the cured film 3, and a copper seed layer was further formed on top of that by sputtering. After that, a photoresist layer was formed, and then metal wiring 4 made of copper, which was electrically connected to the LED 2, 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. Then, the photoresist, seed layer, and barrier metal were removed (corresponding to step (D5)). The thickness of the metal wiring 4a formed on the portion of the surface of the cured film 3 was 5 μm.

[0360] 7e-f, steps (D2), (D3), (D4) and (D5) were then 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.

[0361] Thereafter, as shown in Fig. 7g, a barrier metal 9 was formed by sputtering in the opening pattern 12 of the cured film 3, thereby forming solder bumps 10. Thereafter, as shown in Fig. 7h, the solder was reflowed at 260°C for 1 minute, and electrically connected to the light-emitting element drive substrate 7 having a driver IC, which is the drive element 8d, via the solder bumps 10. Thereafter, the support substrate 18 was peeled off, and the opposing substrate 5 was attached using an adhesive or the like, thereby obtaining a display device 1 having a plurality of LEDs 2.

[0362] 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 a resin film 19 was formed by lamination.

[0363] Examples 3 to 14 Display devices 3 to 14 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 14.

[0364] Example 15 In Example 1, the resin composition 1 was applied onto the supporting substrate 18 and the light-emitting element 2 so that the thickness after heat treatment would be 20 μm to form a resin film 19. As a result, a display device 15 was obtained in the same manner as in Example 1, except that the total thickness of the three-layer cured film 3 became 40 μm.

[0365] Example 16 An embodiment of the display device of the present invention will be described with reference to the cross-sectional views of the manufacturing process shown in FIG. First, as shown in Fig. 8a, an electrode pad 18 made of copper was placed on a support substrate 18 (corresponding to step (E1)). The thickness of the electrode pad was 0.2 µm. Next, as shown in FIG. 8b, resin composition 2 described in Table 1 was applied onto support substrate 18 and metal pad 17 so as to have a thickness of 10 μm after heat treatment, thereby forming resin film 19 (corresponding to step (E2)).

[0366] Next, as shown in FIG. 8c, a plurality of opening patterns 12 were formed in the resin film 19 under the same conditions as in the photolithography process shown in Example 1 (corresponding to process (E3)).

[0367] Next, the resin film 19 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)).

[0368] Next, in FIG. 8c, in order to improve the adhesion between the cured film 3 and the metal 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.

[0369] Next, as shown in FIG. 8d, a photoresist layer was formed, and then metal 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 metal wiring 4 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.

[0370] Thereafter, steps (E2), (E3), (E4), and (E5) were repeated twice to form three layers of cured films 3 having metal wiring 4 therein, as shown in Fig. 8e. As a result, the total thickness of the three layers of cured films 3 was 30 µm.

[0371] Next, as shown in Fig. 8f, the LED 2 was placed on the cured film 3 so as to maintain electrical connection with the metal wiring 4 (corresponding to step (E6)). The thickness of the LED 2 was 7 µm.

[0372] Next, as shown in Fig. 8g, a resin film 19 made of the resin composition 2 was formed on the light-emitting element 2 and cured by heat treatment to form a cured film 21. 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 a cured film 3.

[0373] Next, as shown in Figure 8h, the support substrate 18 was peeled off, and a light-emitting element driving substrate 7 having a driver IC, which is a driving element 8, was electrically connected via solder bumps 10, and an opposing substrate 5 was attached to the LED 2 using an adhesive or the like, thereby obtaining a display device 16 having multiple LEDs 2.

[0374] Example 17 A display device 17 was obtained in the same manner as in Example 15, except that the resin composition 2 in Example 15 was changed to the resin composition 10.

[0375] Example 18 A display device 18 was obtained in the same manner as in Example 16, except that T693 / R4000 Series (manufactured by Nagase ChemteX Corporation) was used as the cured film 21 formed on the light-emitting element 2 and the cured film 21 was formed by heat treatment at 150°C for 60 minutes.

[0376] Example 19 As shown in FIG. 9f, after forming multiple layers of the cured film 3 shown in FIG. 8e in the same manner as in Example 15, partition walls 15 were formed between and around the LEDs 2 to be disposed later using the resin composition 2 (step (E9) 9g), then, as shown in FIG. 9h, the support substrate 18 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 solder bumps 10, and an opposing substrate 5 was attached to the LEDs 2 using an adhesive or the like, thereby obtaining a display device 19 having a plurality of LEDs 2. The LEDs 2 had a thickness of 7 μm, and the partition walls had a thickness of 10 μm.

[0377] Example 20 As shown in FIG. 18a, partition walls 15 were formed on a support substrate 18 (corresponding to step D8). Next, as shown in FIG. 18b, LEDs 2 were formed between the partition walls 15 (corresponding to step (D1)). Except for this, a display device 22 was manufactured using the same steps as in Example 3. The LEDs 2 had a thickness of 7 μm, and the partition walls 15 were formed to a thickness of 10 μm. The partition walls 15 were made of an acrylic resin containing a known white pigment.

[0378] Example 21 A display device 23 was obtained in the same manner as in Example 1, except that the resin composition 1 in Example 1 was changed to the resin composition 17, a photoresist was formed before exposure, and the photoresist was removed after development.

[0379] Example 22 A display device 24 was obtained in the same manner as in Example 1, except that the resin composition 1 in Example 1 was changed to the resin composition 18.

[0380] Example 23 A display device 25 was obtained in the same manner as in Example 1, except that the resin composition 1 in Example 1 was changed to the resin composition 19 and the exposed resin film 19 was developed using cyclopentanone.

[0381] (Examples 24 to 25) Resin composition 1 in Example 1 was changed to resin compositions 20 to 21, and resin composition 1 listed in Table 1 was applied to a support substrate 18 and a light-emitting element 2 so that the thickness would be 8 μm after heat treatment, thereby forming a resin film 19 (corresponding to process (D2)).

[0382] 7c, the resin film 19 was irradiated with i-line (365 nm) through a mask having a desired pattern. The exposed resin film 19 was developed using a 2.38 mass % tetramethylammonium (TMAH) aqueous solution to form a plurality of opening patterns 12 penetrating the resin film 19 in the thickness direction (corresponding to step (D3)).

[0383] Next, the resin film 19 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 harden it, thereby forming a cured film 3 with a thickness of 10 μm (corresponding to step (D4)). The resin film 19 hardens as it is and becomes the cured film 3.

[0384] Next, as shown in Figure 7d, a titanium barrier metal was sputtered onto the cured film 3, and a copper seed layer was further formed on top of that by sputtering. After that, a photoresist layer was formed, and then metal wiring 4 made of copper, which was electrically connected to the LED 2, 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. Then, the photoresist, seed layer, and barrier metal were removed (corresponding to step (D5)). The thickness of the metal wiring 4a formed on the portion of the surface of the cured film 3 was 2 μm.

[0385] Thereafter, as shown in Figures 7e-f, steps (D2), (D3), (D4), and (D5) were repeated twice to form three layers of cured film 3. The second and third layers of cured film 3 were formed so that their thicknesses were 4 µm after heat treatment. As a result, the total thickness of the three layers of cured film 3 was 16 µm. Display devices 26-27 were obtained in the same manner as in Example 1.

[0386] Example 26 A display device 28 was obtained in the same manner as in Example 16, except that resin composition 2 in Example 16 was changed to resin composition 18.

[0387] Example 27 A display device 25 was obtained in the same manner as in Example 16, except that resin composition 2 in Example 16 was changed to resin composition 19 and the exposed resin film 19 was developed using cyclopentanone.

[0388] (Examples 28 to 29) Resin composition 2 in Example 16 was changed to resin compositions 20 to 21, and as shown in Figure 8b, resin compositions 20 to 21 were applied onto a support substrate 18 and a metal pad 17 so that the thickness after heat treatment would be 4 μm, thereby forming a resin film 19 (corresponding to step (E2)).

[0389] Next, as shown in FIG. 8c, a plurality of opening patterns 12 were formed in the resin film 19 under the same conditions as in the photolithography step shown in Example 1 (corresponding to step (E3)).

[0390] Next, the resin film 19 was cured under the same conditions as in Example 1 to form a cured film 3 having a thickness of 4 μm (corresponding to step (E4)).

[0391] Next, in FIG. 8c, in order to improve the adhesion between the cured film 3 and the metal 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.

[0392] Next, as shown in FIG. 8d, a photoresist layer was formed, and then metal 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 metal wiring 4 formed on the portion of the surface of the cured film 3 was 2 μm. Thereafter, the photoresist, seed layer, and barrier metal were removed.

[0393] Thereafter, steps (E2), (E3), (E4), and (E5) were repeated twice to form three layers of cured films 3 having metal wiring 4 therein, as shown in FIG. 8e. As a result, the total thickness of the three layers of cured films 3 was 12 μm. Display devices 30 to 31 were obtained in the same manner as in Example 16 except for the above.

[0394] Example 30 In Example 3, as shown in Fig. 7h, a groove was formed by laser processing on the side surface of the light-emitting element driving substrate 7, and titanium and copper were formed in this order by sputtering, and then copper was formed by plating to form the metal wiring 4c (corresponding to step D9). Except for this, the same method as in Example 3 was carried out to obtain a display device 32.

[0395] Example 31 In Example 16, as shown in Fig. 8h, a groove was formed by laser processing on the side surface of the light-emitting element driving substrate 7, and titanium and copper were formed in this order by sputtering, and then copper was formed by plating to form the metal wiring 4c (corresponding to step E11). Except for this, the same method as in Example 16 was carried out to obtain a display device 33.

[0396] Example 32 On the side surface of the light-emitting element driving substrate 7 of Example 30, a conductive film 26 was used as shown in FIG. 19h, and the photosensitive conductive paste 1 of Preparation Example 1 was used as the conductive film 26 (corresponding to step D10). Except for this, the same method as in Example 30 was carried out to obtain a display device 34. The conductive film 26 was produced as follows.

[0397] <Preparation of Conductive Film 26> Photosensitive conductive paste 1 was applied to a 16 μm-thick PET film coated with a release agent so that the film thickness after drying would be 6.0 μm, and the resulting coating film was dried in a drying oven at 100°C for 10 minutes. After that, an exposure device equipped with an ultra-high pressure mercury lamp was used to expose the film to 350 mJ / cm. 2 After exposure to an exposure dose of 1000 ppm, the sample was spray-developed using a 0.1% by mass aqueous solution of sodium carbonate as the 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 part of the wiring was located at the edge of the glass with the R-chamfered portion, and the side of the glass was pressed against a hot plate at 130°C for 30 seconds. The remaining part was then transferred using a hot roll laminator at 130°C and 1.0 m / min.

[0398] Example 33 19h, a conductive film 26 was used on the side surface of the light-emitting element driving substrate 7 of Example 31, and the photosensitive conductive paste 1 described in Example 32 was used as the conductive film 26 (corresponding to step E12). Otherwise, the same method as in Example 31 was carried out to obtain a display device 35.

[0399] Example 34 A display device 36 was obtained in the same manner as in Example 30, except that a printed wiring board was used as the light-emitting element driving substrate 7 of Example 30 and the driving elements 8 and metal wiring 4 were connected via wiring and bumps in the printed wiring board.

[0400] Example 35 A display device 37 was obtained in the same manner as in Example 31, except that a printed wiring board was used as the light-emitting element driving substrate 7 of Example 31 and the driving elements 8 and metal wiring 4 were connected via wiring and bumps in the printed wiring board.

[0401] Example 36 As shown in FIG. 20a, a light-shielding layer 27 was formed on a support substrate 18 (corresponding to step D11). Next, as shown in FIG. 20a, an LED 2 was formed between the light-shielding layers 27 (corresponding to step (D1)). Except for this, a display device 38 was manufactured using the same steps as in Example 3. The light-shielding layer 27 was manufactured as follows.

[0402] <Preparation of Light-Shielding Layer 27> The colored resin composition 1 was applied to a support substrate 18 so that the thickness would be 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 equipped with an ultra-high pressure mercury lamp. 2 The film was exposed to an exposure dose of 1000 ppm. The film was then developed using an alkaline developer of 0.045 wt % potassium hydroxide aqueous solution, followed by rinsing with pure water to obtain a patterned film. The resulting patterned film was post-baked in a hot air oven at 230°C for 30 minutes to obtain a light-shielding layer.

[0403] Example 37 A display device 39 was produced in the same manner as in Example 36, except that the light-shielding layer 27 in Example 36 was changed to the colored resin composition 2 to form the light-shielding layer 27.

[0404] Example 38 In FIG. 7f, the display device 40 was obtained in the same process as in Example 3, except that the thickness of the metal wiring 4a in contact with the bump 10 was 10 μm, the thickness of the cured film 3 formed on a portion of the surface of the metal wiring 4a was 15 μm, and the total thickness of the cured film 3 was 35 μm.

[0405] Example 39 In FIG. 8b, a display device 41 was obtained in the same manner as in Example 16, except that the thickness of the metal pad 18 was 10 μm, the thickness of the cured film 3 formed on a portion of the surface of the metal pad was 15 μm, and the total thickness of the cured film 3 was 35 μm.

[0406] Example 40 An embodiment of the display device of the present invention will be described with reference to the cross-sectional views of the manufacturing process shown in FIG. 22a, a TFT array substrate was used as the light-emitting element driving substrate 7, and resin composition 2 described in Table 1 was applied onto the light-emitting element driving substrate 7 so that the thickness would be 3 μm after heat treatment, to form a resin film 19 (corresponding to step (F1)). The thickness of the metal wiring 4 was 1 μm.

[0407] Next, a plurality of opening patterns 12 were formed in the resin film 19 under the same conditions as in the photolithography step shown in Example 2 (corresponding to step (F2)).

[0408] Next, the resin film 19 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)).

[0409] Next, as shown in Figure 22b, the wiring or conductive film 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), ITO was formed as wiring 24 on a portion of the surface of the cured film 3 by a sputtering method. Thereafter, unnecessary photoresist was removed (corresponding to step (F4)). The thickness of the ITO was 0.1 µm.

[0410] Next, as shown in FIG. 22c, steps (F1), (F2) and (F3) were repeated to cure resin composition 3 shown in Table 1, thereby forming a cured film 3 having a thickness of 3 μm.

[0411] Next, as shown in Fig. 22d, partition walls 15 were formed on the cured film 3. Next, as shown in Fig. 22d, LEDs 2 were formed between the partition walls 15 (corresponding to step (F5)). The thickness of the LEDs 2 was 7 µm, and the thickness of the partition walls 15 was 8 µm. The partition walls 15 were made of a known acrylic resin containing a white pigment.

[0412] Thereafter, as shown in Fig. 22e, an opposing substrate 5 was attached using an adhesive. In addition, a conductive film 26 was formed using the photosensitive conductive paste 1 of Preparation Example 1, and a driving element 8 such as a driver IC was electrically connected to the light-emitting element 2 via the conductive film 26 and the metal wiring 4 and wiring 24 extending into the cured film 3, thereby obtaining a display device 42 having a plurality of LEDs 2.

[0413] (Implementation 41-42) Display devices 43 and 44 were obtained in the same manner as in Example 40, except that resin composition 2 in Example 40 was changed to resin compositions 13 and 21.

[0414] As a result, the display devices 1 to 19 and 22 to 44 had sufficiently low light transmittance for the cured film 3, which concealed the metal wiring 4, making it difficult to see from the outside, thereby enhancing the design. Furthermore, the thickness of the cured film was smaller than that of conventional flexible substrates, which enabled the suppression of wiring defects such as wiring shorts due to a low package height and shortened wiring distance, reduced loss, and improved high-speed response. Furthermore, the display devices 1 to 13 and 15 to 19 were capable of microfabrication, allowing for the application of minute light-emitting elements and the high-density packaging of light-emitting elements. Furthermore, a cured film made of a resin composition could also be used as the partition wall 15, and forming the partition wall facilitated the bonding of the opposing substrate. Furthermore, the display devices 13, 24 to 25, 30 to 31, and 43 to 44 had a black cured film 3, which concealed the metal wiring 4, making it difficult to see from the outside, thereby enhancing the design. Furthermore, the visibility was also improved by reducing external light reflection and improving contrast. Furthermore, in display devices 1-19, 22-35, and 38-44, at least a portion of the metal wiring or conductive film extends to the side of the substrate, thereby enabling the display device itself to be lower in profile and with improved high-speed response, and further miniaturization and a narrower frame. Furthermore, display devices 38 and 39 formed a light-shielding layer between multiple light-emitting elements, thereby suppressing light leakage from the light-emitting elements and color mixing between pixels, and improving contrast without significantly compromising light extraction efficiency. In display devices 37 and 38, the metal wiring near the bumps 10 was thicker than the metal wiring near the LEDs 2, thereby suppressing wiring defects when connecting the light-emitting element drive substrate 7 using the bumps 10, resulting in a highly reliable display device.

[0415] (Comparative Examples 1 and 2) Display devices 20 to 21 were obtained in the same manner as in Example 1, except that resin composition 1 in Example 1 was changed to resin compositions 15 to 16.

[0416] As a result, in the display devices 20 to 21, the light transmittance of the cured film 3 was sufficiently high, but the concealment ability of the cured film 3 for the metal wiring 4 was insufficient, and the metal wiring 4 was visible from the outside. [Explanation of symbols]

[0417] 1 Display device 2 Light-emitting element 3 Cured film 4, 4c metal wiring 4a Thickness of the metal wiring on the surface of the cured film 4b Thickness of the metal wiring extending into the opening pattern penetrating the thickness direction of the cured film 5 Opposing substrate 6 electrode terminal 7 Light emitting element drive board 8 Drive element 9 Barrier Metal 10 Solder Bumps 11a Specified area A 11b Specified area B 12 Opening Pattern 13 Bottom surface of metal wiring 4 14 Maximum length of bottom surface 15 Bulkhead 16 External board 17 Metal Pad 18 Support substrate 19 Resin film 20 Total thickness of the cured film 21 Cured film 22 TFT 23 TFT insulating layer 24 Wiring 25 Contact Hole 26 Conductive film 27 Light blocking layer 28 Inclined Edge 29 Angle of Inclined Side 30 Thickness of cured film 3 31 Position at 1 / 2 thickness of effect film 3

Claims

1. A display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, the light-emitting element has a pair of electrode terminals on either one surface, the pair of electrode terminals are connected to the plurality of metal wirings extending in the cured film, and the plurality of metal wirings maintain electrical insulation due to the cured film; the cured film is a film obtained by curing (A) a resin composition containing one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, copolymers thereof, acrylic resin, phenolic resin, and cardo resin, and the transmittance of the cured film at a thickness of 1 μm for light with a wavelength of 450 nm is 0.1% or more and 95% or less; A display device, wherein the resin composition containing the resin (A) further contains a photosensitizer (B).

2. The display device according to claim 1 , wherein the transmittance of the cured film at a standard thickness of 5 μm for light with a wavelength of 450 nm is 0.1% or more and 79% or less.

3. The display device according to claim 1 , wherein the transmittance of the cured film at a thickness of 1 μm for light with a wavelength of 450 nm is 0.1% or more and 25% or less.

4. 4. The display device according to claim 1, wherein the cured film has a total thickness of 5 to 100 μm.

5. 5. The display device according to claim 1, wherein the number of layers of the cured film is 2 to 10.

6. The display device according to any one of claims 1 to 5, wherein an opening pattern penetrating the cured film in the thickness direction is provided, and the metal wiring is arranged at least in the opening pattern, and the longest length of the bottom surface portion of the metal wiring formed at a position in contact with the light-emitting element is 2 to 20 μm.

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

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

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

10. 10. The display device according to claim 1, further comprising a driving element and a substrate, the driving element being connected to the light-emitting element through metal wiring, and at least a portion of the metal wiring extending to a side surface of the substrate.

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

12. The display device according to any one of claims 1 to 11, wherein the resin (A) contains one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof.

13. The display device according to any one of claims 1 to 12, wherein the resin composition containing the resin (A) further contains a colorant (C), and the colorant (C) contains a colorant (C-1) having an absorption maximum in a wavelength range of 400 nm or more and 490 nm or less.

14. The display device according to any one of claims 1 to 13, wherein the resin composition containing the (A) resin further contains a (C) colorant, and the (C) colorant contains (C-2) a colorant having an absorption maximum in a wavelength range of more than 490 nm and not more than 580 nm.

15. The display device according to any one of claims 1 to 13, wherein the resin composition containing the (A) resin further contains a (C) colorant, and the (C) colorant contains (C-3) a colorant having an absorption maximum in a wavelength range of more than 580 nm and not more than 800 nm.

16. 14. The display device according to claim 1, wherein the (C) colorant further contains, in addition to the (C-1) colorant, (C-2) a colorant having an absorption maximum in a wavelength range of more than 490 nm to 580 nm or less, and (C-3) a colorant having an absorption maximum in a wavelength range of more than 580 nm to 800 nm or less.

17. 17. The display device according to claim 1, wherein the resin composition containing the resin (A) is positive photosensitive.

18. A display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, the light-emitting element has a pair of electrode terminals on either one surface, the pair of electrode terminals are connected to the plurality of metal wirings extending in the cured film, and the plurality of metal wirings maintain electrical insulation due to the cured film; the cured film is a film obtained by curing (A) a resin composition containing one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, copolymers thereof, acrylic resin, phenolic resin, and cardo resin, and the transmittance of the cured film at a thickness of 1 μm for light with a wavelength of 450 nm is 0.1% or more and 95% or less; The display device further comprises a driving element and a substrate, the driving element being connected to the light-emitting element through a metal wiring, and at least a part of the metal wiring extending to a side surface of the substrate.

19. A method for manufacturing a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, comprising: Step (D1) of disposing the light-emitting element on a supporting substrate; a step (D2) of forming a resin film on the supporting substrate and the light-emitting element, the resin film being made of a resin composition containing (A) one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, copolymers thereof, acrylic resin, phenolic resin, and cardo resin, and (B) a photosensitizer; a step (D3) of forming a pattern of a plurality of penetrating openings in the resin film by exposing and developing the resin film; a step (D6) of curing the resin film to form a cured film having a transmittance of 0.1% or more and 95% or less for light having a wavelength of 450 nm at a thickness of 1 μm; and a step (D5) of forming the metal wiring in at least a part of the surface of the cured film and in the opening pattern of the cured film; A method for manufacturing a display device having the above structure.

20. 20. The method for manufacturing a display device according to claim 19, further comprising the step of repeating the steps (D2), (D3), (D6), and (D5) a plurality of times to form a plurality of layers of the cured film having the metal wiring therein.

21. A method for manufacturing a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, comprising: Step (E1) of disposing metal pads on a support substrate; (A) forming a resin film on the support substrate and the metal pads, the resin film being made of a resin composition containing one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, copolymers thereof, acrylic resin, phenolic resin, and cardo resin; a step (E3) of forming a pattern of a plurality of through-holes in the resin film by exposing and developing the resin film; a step (E10) of curing the resin film to form the cured film having a transmittance of 0.1% or more and 95% or less for light with a wavelength of 450 nm at a thickness of 1 μm; A step (E5) of forming the metal wiring on at least a part of the surface of the cured film and the opening pattern of the cured film; and a step (E6) of disposing the light-emitting element on the cured film so as to maintain electrical connection with the metal wiring; A method for manufacturing a display device having the above structure.

22. 22. The method for manufacturing a display device according to claim 21, further comprising the step of repeating the steps (E2), (E3), (E10), and (E5) a plurality of times to form a plurality of layers of the cured film having the metal wiring therein.

23. 23. The method for manufacturing a display device according to claim 21, further comprising, after the step (E5), a step (E9) of providing a partition wall having a thickness equal to or greater than a thickness of the light-emitting element.

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