Display device

Abstract

DISPLAY DEVICE IN WHICH WIRING FAILURE SUCH AS SHORT CIRCUIT OF WIRING OR CONNECTION FAILURE OF LIGHT-EMITTING ELEMENT IS LESS LIKELY TO OCCUR SOLUTION: A display device comprising at least a metal wiring, a cured film, and a plurality of light-emitting elements, wherein each of the light-emitting elements has a pair of electrode terminals on one surface thereof, and the pair of electrode terminals are connected to the plurality of metal wirings extending in the cured film, the plurality of metallic wirings are electrically insulated by the cured film, the metallic wirings include a plurality of metallic wirings (K1) extending in a thickness direction of the cured film and a plurality of metallic wirings (K2) connected to the metallic wirings (K1) and extending in a planar direction perpendicular to the thickness direction of the cured film, and the cured film is in contact with a part of surfaces of the metallic wirings (K2).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a display device such as an LED display and a method for manufacturing the same. [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 of a light emission failure rate.

[0006] Furthermore, the LED display devices described in the above document have the problem that, as LEDs become increasingly miniaturized, high voltages must be applied to the fine metal wiring, which makes the metal wiring prone to deterioration and electrical leakage, resulting in a high defect rate after reliability testing, which is an accelerated test of actual use. [Means for solving the problem]

[0007] In order to solve the above problems, a first aspect of the present invention has the following configuration.

[0008] [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 one surface, and 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, and the metal wirings have a plurality of metal wirings (K1) extending in the thickness direction of the cured film, and a plurality of metal wirings (K2) connected to the metal wirings (K1) and extending in a planar direction perpendicular to the thickness direction of the cured film, and the cured film a display device having a cured film formed by curing a resin composition containing a resin (A), the cured film being in contact with a surface of a portion of the metal wiring (K2), the display device having at least a portion (G) in which the line-to-line spacing H1 between two adjacent metal wirings (K2) is 1 to 20 μm, and in the portion (G), when the thickness of the metal wiring (K2) is H2 (μm), the thickness of the cured film is H3 (μm), and the depth of a step in the cured film generated in the portion (G) is H4 (μm), H3 / H2 is 1.4 to 4.0, and a step flattening rate P (%) represented by (Equation 1) is 70 to 99%. P(%)=(1-(H4 / H2))×100...(Formula 1) In order to solve the above problems, a second aspect of the present invention has the following configuration.

[0009] [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 the metal wirings extending in the cured film, and the plurality of metal wirings are configured to maintain electrical insulation by the cured film, and the cured film is a film obtained by curing a resin composition containing (A) resin, and the dielectric breakdown voltage of the cured film is 360 kV / mm or more and 600 kV / mm or less.

[0010] [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 an (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 (D4) of curing the resin film to form the cured film having a dielectric breakdown voltage of 360 kV / mm or more and 600 kV / mm or less; 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.

[0011] [3] A method for manufacturing a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, A method for manufacturing a display device, comprising: a step (E1) of arranging metal pads on a support substrate; a step (E2) of forming a resin film on the support substrate and the metal pads, the resin film being made of a resin composition containing (A) resin; 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 (E4) of curing the resin film to form the cured film having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less; a step (E5) of forming 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 element on the cured film so as to maintain electrical connection with the metal wiring. [Effects of the Invention]

[0012] The display device according to the first aspect of the present invention has a film configuration with high step flatness due to the cured film, which can suppress wiring defects such as short circuits in wiring and connection defects of light-emitting elements, and can provide a display device that can reduce the rate of light emission defects when used as a display device.

[0013] The display device according to the second aspect of the present invention can provide a display device with a low defect rate even after a reliability test, which is an accelerated test under actual use. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a front cross-sectional view showing one embodiment of a display device of the present invention. [Figure 2] 2 is an enlarged front cross-sectional view of designated area A in FIG. 1. [Figure 3] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention. [Figure 4] 4 is an enlarged front cross-sectional view of designated area A in FIG. 3. [Figure 5] 4 is an enlarged front cross-sectional view (upper part) of designated area B in FIG. 3 and a bottom view (lower part) of designated area B excluding light-emitting elements. [Figure 6] This is an enlarged cross-sectional view (upper part) of the top surface of the designated area C in Figure 3, a cross-sectional view (middle part) of the designated area C excluding the wiring in a plane perpendicular to the front of the designated area C, and a bottom view (lower part) of the designated area C excluding the opposing substrate. [Figure 7] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a reflective film is provided. [Figure 8] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which partition walls are provided. [Figure 9] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which partition walls are provided in the cured film. [Figure 10] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a reflective film and a partition wall are provided. [Figure 11] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which partition walls are provided in a cured film and a reflective film is provided thereon. [Figure 12] FIG. 10 is a front cross-sectional view of another embodiment of the display device of the present invention, in which a driving element is disposed in a cured film. [Figure 13] FIG. 10 is a front cross-sectional view of another embodiment of the display device of the present invention, which has another configuration in which a driving element is disposed in a cured film. [Figure 14] 1A to 1C are cross-sectional views illustrating a manufacturing process of one embodiment of a display device of the present invention. [Figure 15]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 16] 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 reflective film is provided. [Figure 17] 10A to 10C are cross-sectional views illustrating steps in manufacturing another example of the display device of the present invention. [Figure 18] 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 19] 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 reflective film is provided. [Figure 20] 1 is a front cross-sectional view showing one embodiment of a display device of the present invention. [Figure 21] 10 is an enlarged front cross-sectional view (upper part) of the designated area B and a bottom view (lower part) of the designated area B excluding the light-emitting element. [Figure 22] This is an enlarged cross-sectional view (upper part) of the top surface of the designated area C, a cross-sectional view (middle part) of the designated area C excluding the wiring in a plane perpendicular to the front of the designated area C, and a bottom view (lower part) of the designated area C excluding the opposing substrate. [Figure 23] FIG. 1 is a front cross-sectional view showing one embodiment of a display device of the present invention in which a reflective 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 partition walls are provided. [Figure 25] 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 26] FIG. 10 is a front cross-sectional view showing another embodiment of the display device of the present invention in which a reflective film and a partition wall are provided. [Figure 27] 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 and a reflective film is provided thereon. [Figure 28] 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 29] 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 30] 1A to 1C are cross-sectional views illustrating a manufacturing process of one embodiment of a display device of the present invention. [Figure 31] 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 32] 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 reflective film is provided. [Figure 33] 10A to 10C are cross-sectional views illustrating steps in manufacturing another example of the display device of the present invention. [Figure 34] 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 35] 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 reflective film is provided. [Figure 36] FIG. 1 is a front cross-sectional view showing one embodiment of a display device of the present invention in which a cured film is provided. [Figure 37] 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 38] 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 39] 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 40] 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 41] 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 42] FIG. 10 is a front cross-sectional view of an opening pattern in a cured film. [Figure 43] 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 44] 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 45] 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 46] 10A to 10C are cross-sectional views illustrating steps in manufacturing another example of the display device of the present invention. [Figure 47] 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 48] 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 49] 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 50] 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 51] 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 52] 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

[0015] 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.

[0016] The present invention is classified into the following two aspects.

[0017] A display device according to a first aspect of the present invention is a display device having at least metal wiring, a cured film, and a plurality of light-emitting elements, wherein the light-emitting elements are provided with a pair of electrode terminals on either one surface, the pair of electrode terminals being connected to a plurality of the metal wirings extending in the cured film, and the plurality of the metal wirings being configured to maintain electrical insulation by the cured film, the metal wirings having a plurality of metal wirings (K1) extending in a thickness direction of the cured film, and a plurality of metal wirings (K2) connected to the metal wirings (K1) and extending in a planar direction perpendicular to the thickness direction of the cured film, the cured film being a film obtained by curing a resin composition containing (A) resin, The display device has a cured film in contact with a portion of the surface of the wire (K2), and the display device has at least a portion (G) in which the line-to-line spacing H1 (unit: μm, hereinafter may be omitted) between two adjacent metal wires (K2) is 1 to 20 μm, and in the portion (G), when the thickness of the metal wire (K2) is H2 (unit: μm, hereinafter may be omitted), the thickness of the cured film (F1) is H3 (unit: μm, hereinafter may be omitted), and the depth of a step in the cured film (F1) generated in the portion (G) is H4 (unit: μm, hereinafter may be omitted), H3 / H2 is 1.4 to 4.0, and the step flattening rate P (%) expressed by (Equation 1) is 70 to 99%. P(%)=(1-(H4 / H2))×100...(Formula 1) The display device according to the first embodiment of the present invention will be described with reference to FIG. 1 as an example of one embodiment.

[0018] Here, to clarify the target components, the metal wiring 4 extending in the thickness direction of the cured film 3 is defined as metal wiring (K1) 4a, and the metal wiring 4 connected to the metal wiring (K1) and extending in a planar direction perpendicular to the thickness direction of the cured film 3 is defined as metal wiring (K2) 4b. Furthermore, with regard to the cured film 3, the cured film 3 in which the metal wiring (K2) 4b is embedded is defined as cured film (F1) 3a.

[0019] In FIG. 1, the display device 1 has a cured film (F1) 3a in which metal wiring (K2) 4b is embedded. The light-emitting element 2 has a pair of electrode terminals 6 on the surface opposite to the surface in contact with the counter substrate 5, and each electrode terminal 6 is connected to a metal wiring 4. The metal wiring 4 is electrically connected to the metal wiring (K1) 4a and metal wiring (K2) 4b extending in the thickness direction of the cured film (F1) 3a. The multiple metal wirings (K1) 4a and (K2) 4b extending in the cured film (F1) 3a are covered by the cured film (F1) 3a, and the cured film (F1) 3a also functions as an insulating film, so that the metal wirings (K1) 4a and (K2) 4b maintain electrical insulation from each other via the cured film (F1) 3a. The term "electrically insulating metal wiring" means that the portions of the metal wiring that require electrical insulation are covered by a cured film obtained by curing a resin composition containing the (A) resin.

[0020] A cured film 29 is provided so as to contact at least a portion of the light-emitting element 2, and the counter substrate 5 is disposed so as to contact the light-emitting element 2 and the cured film 29. In the embodiment shown in FIG. 1, the cured film (F1) 3a has a single layer configuration, but multiple layers of the cured film (F1) 3a in which the metal wiring (K2) 4b is embedded may be laminated. In the embodiment shown in FIG. 1, the light-emitting element 2 is electrically connected to a driving element 8 attached to a light-emitting element driving substrate 7 provided opposite the counter substrate 5 through the metal wiring (K1) 4a, the metal wiring (K2) 4b, and the metal wiring 22, thereby controlling the light emission of the light-emitting element 2. The light-emitting element driving substrate 7 is electrically connected to the metal wiring (K1) 4a and the metal wiring (K2) 4b via, for example, solder bumps 10. Furthermore, a barrier metal 9 may be disposed to prevent diffusion of metals such as the metal wiring 4 and the metal wiring (K2) 4b. Note that, hereinafter, the metal wiring 22 may penetrate the light-emitting element driving substrate 7 and connect to the driving element 8. After the metal wiring 4b and the hardened film 3a are formed on the support substrate, the support substrate can be removed and solder bumps 10 and the light emitting element driving substrate 7 can be attached thereto, as will be described later.

[0021] The step planarization rate in the first embodiment of the present invention will be described. Fig. 2 shows an enlarged front cross-sectional view of the designated area A11a in Fig. 1. The cured film (F1) 3a is disposed so as to bury the metal wiring (K2) 4b, and the metal wiring 4 includes the metal wiring (K1) 4a extending in the thickness direction of the cured film (F1) 3a in the cured film (F1) 3a, and the metal wiring (K2) 4b connected to the metal wiring (K1) extending in a planar direction perpendicular to the thickness direction of the cured film (F1) 3a.

[0022] The display device according to the first embodiment of the present invention has at least a region (G) 28 (hereinafter also referred to as region (G)) in which the line spacing H1 between two adjacent metal wirings (K2) 4b is 1 to 20 μm. The region (G) 28 is defined as the region of the cured film (F1) 3a located above and between two adjacent metal wirings (K2) 4b with the line spacing H1, when viewed from the perspective of the cured film (F1) 3a in which the metal wirings (K2) 4b are embedded, as shown by the dashed dotted line in FIG. 2, with the metal wirings (K2) 4b at the bottom and the metal wiring (K1) 4a at the top.

[0023] When the cured film (F1) 3a is disposed so as to bury the metal wiring (K2) 4b, steps may occur on the surface of the cured film (F1) 3a. The greater the depth H4 of these steps, the more likely problems will occur in the subsequent wiring and light-emitting element formation processes, resulting in wiring defects such as wiring shorts and poor connection of the light-emitting elements, which may result in poor light emission in the resulting display device. Therefore, by controlling the step planarization rate P, expressed by the above-mentioned formula 1, for the thickness H2 of the metal wiring (K2) 4b and the step depth H4 of the cured film (F1) 3a within a range of 70 to 99%, wiring defects such as wiring shorts and poor connection of the light-emitting elements can be suppressed, thereby reducing the rate of light emission defects in the resulting display device. If the step planarization rate P is less than 70%, the step planarization rate will be insufficient, which may lead to wiring defects such as wiring shorts and poor connection of the light-emitting elements, resulting in poor light emission. The step planarization rate P is preferably 75 to 99%, more preferably 80 to 99%, and even more preferably 90 to 97%.

[0024] Here, the step depth H4 in the step flattening rate P refers to the maximum value of the step on the cured film (F1) between two adjacent metal wirings (K2) with a line spacing H1 between them. In Figure 2, this refers to the step depth H4.

[0025] The depth H4 of the step of the cured film (F1) may be measured by measuring a cross section of the corresponding portion G of the display device. In addition, when the cured film (F1) is formed in multiple layers, the cross section of the corresponding portion G when any one of the cured films (F1) is formed may be measured.

[0026] Regarding the thickness H2 of the metal wiring (K2) and the thickness H3 of the cured film (F1), H3 / H2 is 1.4 to 4.0.

[0027] The thickness H2 of the metal wiring (K2) refers to the thickness at the center of the wiring width of the metal wiring (K2) at the location of an arbitrary portion (G).

[0028] The thickness H3 of the cured film (F1) refers to the thickness of the cured film (F1) at the location of the step depth H4.

[0029] The thickness H2 of the metal wiring (K2) 4b and the thickness H3 of the cured film (F1) may be measured by measuring the cross section of the corresponding portion of the display device. In addition, when a plurality of layers of the cured film (F1) are formed, the cross section of the corresponding portion may be measured when any of the cured films (F1) is formed.

[0030] This allows the film to function as an insulating film or protective film for appropriate metal wiring, suppressing the step caused by laminating the cured film, metal wiring, and light-emitting element, thereby preventing wiring defects such as wiring shorts and connection defects of light-emitting elements, thereby reducing the rate of light emission defects when used in a display device. If H3 / H2 is less than 1.4, the step may not be sufficiently suppressed, while if H3 / H2 exceeds 4.0, this may cause problems in terms of reducing the height of the display device itself, preventing wiring defects such as wiring shorts due to shorter wiring distances, suppressing loss, and improving high-speed response. H3 / H2 is preferably 1.6 to 3.5, more preferably 1.8 to 3.0.

[0031] The cured film 3 is a film obtained by curing a resin composition containing the (A) resin described below.

[0032] 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.

[0033] The cured film 29 may be composed of a cured film obtained by curing a resin composition containing (A) resin or a resin sheet, or may be composed of a material other than a cured film obtained by curing a resin composition containing (A) resin or a resin sheet, and known materials such as epoxy resin, silicone resin, and fluororesin may be used.

[0034] Another embodiment is shown in FIG. 3. In FIG. 3, the display device 1 has a plurality of light-emitting elements 2 on a counter substrate 5, and a cured film 3 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. 3, a configuration is illustrated in which a total of three layers are laminated, with multiple cured films (F1) 3a laminated on the cured film 3 arranged so as to contact at least a portion of the light-emitting elements 2, but this is not limiting. 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 (K1) 4a and a metal wiring (K2) 4b extending in the cured film (F1) 3a. The multiple metal wiring (K1) 4a and metal wiring (K2) 4b extending in the cured film (F1) 3a are covered by the cured film (F1) 3a, and the cured film (F1) 3a also functions as an insulating film, thereby maintaining electrical insulation. The embodiment illustrated in FIG. 1 is an arrangement in which the light emitting elements are arranged vertically opposite to each other.

[0035] Figure 4 shows an enlarged front cross-sectional view of area A in Figure 3. The explanation of each component is the same as in Figure 2.

[0036] In the present invention, the thickness H2 of the metal wiring (K2) is preferably 1.5 to 10 μm.

[0037] This reduces wiring resistance and reduces wiring delays. Furthermore, since the aforementioned H3 / H2 is 1.4 to 4.0, the cured film can be formed to a sufficient thickness, suppressing steps that occur when stacking the cured film, metal wiring, and light-emitting elements. This prevents wiring defects such as wiring shorts and connection defects of light-emitting elements, thereby reducing the rate of defective light emission when used in a display device. If the thickness H2 of the metal wiring (K2) is less than 1.5 μm, the wiring resistance may increase and delays may be more likely to occur. If the thickness H2 of the metal wiring (K2) is more than 10 μm, this may cause problems in terms of reducing the height of the display device itself. Preferably, the thickness H2 of the metal wiring (K2) is 2 to 9 μm, and more preferably, the thickness H2 of the metal wiring (K2) is 3 to 8 μm.

[0038] 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. 3, 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.

[0039] A display device according to a second aspect of the present invention is 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 being connected to a plurality of the metal wirings extending in the cured film, and the plurality of the 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 dielectric breakdown voltage of the cured film being 360 kV / mm or more and 600 kV / mm or less.

[0040] The display device according to the second embodiment of the present invention will be described with reference to FIG. 20 as an example of one embodiment.

[0041] In FIG. 20 , 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. The embodiment shown in FIG. 20 illustrates a configuration in which a total of three layers are laminated, with multiple cured films 3 laminated 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, thereby maintaining electrical insulation. The term "metal wiring maintaining 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.

[0042] The cured film 3 is a film obtained by curing a resin composition containing the resin (A) described below. It is important that the breakdown voltage of the cured film 3 is 360 kV / mm or more and 600 kV / mm or less. This suppresses deterioration of the metal wiring and electrical leakage, and reduces the failure rate even after a reliability test, which is an accelerated test for practical use. The breakdown voltage is preferably 450 kV / mm or more and 600 kV / mm or less, and more preferably 500 kV / mm or more and 600 kV / mm or less. If the breakdown voltage is less than 360 kV / mm, deterioration of the metal wiring and electrical leakage will occur, resulting in a high failure rate. If the breakdown voltage exceeds 600 kV / mm, charge will accumulate, causing electrostatic breakdown of the wiring and driving elements, resulting in a high failure rate. Examples of reliability tests include impact tests, high-temperature retention tests, constant-temperature high-humidity tests, and thermal cycle tests.

[0043] The breakdown voltage may be measured by peeling off the cured film from the display device, or by measuring the breakdown voltage of a cured film prepared under the conditions of the method for evaluating the tensile strength 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.

[0044] 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.

[0045] As another embodiment of the display device according to the first and second aspects of the present invention, as shown in Fig. 36, a configuration is exemplified in which a cured film 29 is provided in the display device of Fig. 3 or 20 so as to be in contact with at least a portion of the light-emitting element 2. The cured film 29 arranged so as to be in contact with at least a portion of the light-emitting element 2 may be made of a cured film obtained by curing a resin composition 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.

[0046] In the first and second aspects of 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.

[0047] 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.

[0048] In the display devices according to the first and second aspects of the present invention, the metal wiring may be a conductive film.

[0049] 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).

[0050] 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.

[0051] 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.

[0052] The conductive particles in the present invention are particles having an electrical resistivity of 10 -5 Conductive films refer to particles made of substances with a resistivity 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. Note that conductive films also include electrodes. Examples of display devices using conductive films are shown in Figures 47 and 48.

[0053] In the first embodiment of the present invention, the cured film preferably has 2 to 10 layers.

[0054] From the viewpoint of arranging multiple light-emitting elements, the cured film is preferably one or more layers. Furthermore, by having two or more layers, unevenness caused by stacking the cured film, metal wiring, and light-emitting elements is suppressed, and wiring defects such as wiring shorts and connection defects of the light-emitting elements can be suppressed. This reduces the rate of light emission defects when used as a display device, and increases the number of metal wirings that can be connected to the light-emitting elements, allowing for the arrangement of multiple light-emitting elements. Furthermore, from the viewpoints of suppressing wiring defects such as wiring shorts due to a low package height and short wiring distances, reducing loss, and improving high-speed response, 10 layers or less is preferable. If the number of layers is less than two, the number of light-emitting elements that can be arranged may be limited. If the number of layers is more than 10, disadvantages may arise in terms of reducing the height of the display device itself, suppressing wiring defects such as wiring shorts due to short wiring distances, suppressing low loss, and improving high-speed response. The number of layers is preferably 2 to 8, more preferably 2 to 5.

[0055] In the second aspect of the present invention, when a plurality of cured films are laminated, the number of layers of the cured films is preferably 2 to 10.

[0056] 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.

[0057] In the first and second aspects of the present invention, the total thickness of the cured film is preferably 5 to 100 μm.

[0058] In the first aspect of the present invention, by making the total thickness of the cured film 5 to 100 μm, steps caused by stacking the cured film, metal wiring, and light-emitting elements are suppressed, and wiring defects such as wiring shorts and connection defects of the light-emitting elements can be suppressed, thereby reducing the rate of defective light emission when used as a display device. Furthermore, it is possible to reduce the height of the display device having the light-emitting elements, suppress wiring defects such as wiring shorts due to shorter wiring distances, suppress loss, and improve high-speed response.

[0059] In the second embodiment of the present invention, the total thickness of the cured film is preferably 5 μm to 100 μm, which can prevent light emitted in all directions from the light-emitting element 2 from being absorbed in the cured film 3, increase the light extraction efficiency, improve brightness, and suppress deterioration of the metal wiring and electrical leakage, thereby reducing the defect rate even after a reliability test, which is an accelerated test for actual use. Furthermore, it is possible to reduce the height of the display device having the light-emitting element itself, suppress wiring defects such as short circuits due to shorter wiring distances, suppress loss, and improve high-speed response.

[0060] 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 Figures 3 and 20, the region indicated by 19 in Figures 3 and 20 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, there is a concern that the metal wiring will not be sufficiently protected, leading to concerns about wiring defects such as short circuits. If the thickness exceeds 100 μm, there is a concern that the light extraction efficiency will be insufficient, and there may be inconveniences in terms of reducing the height of the display device itself, preventing wiring defects such as short circuits due to shorter wiring distances, preventing loss, and improving high-speed response.

[0061] In the first and second aspects of the present invention, the cured film is provided with an opening pattern penetrating through the film in the thickness direction, and metal wiring is disposed at least in the opening pattern, and it is preferred 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.

[0062] In a first embodiment of the present invention, Fig. 5 shows an enlarged front cross-sectional view (upper portion) of the designated region B in Fig. 3 and a bottom view (lower portion) of the designated region B excluding the light-emitting element. In the enlarged front cross-sectional view (upper portion) of the designated region B in Fig. 5, 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 (K1) 4a formed in the opening pattern 12 is shown. The bottom portion 13 of the metal wiring (K1) 4a extends into the cured film 3 up to a position where it contacts the light-emitting element 2 and the electrode terminal 6 of the light-emitting element 2, and shows the shape of the metal wiring (K1) 4a at the contact point.

[0063] The bottom view (lower portion) of the designated area B in Figure 5 excluding the light-emitting element is a view from below of the bottom surface 13 of the metal wiring (K1) 4a extending to the cured film 3 with the light-emitting element 2 removed, showing the bottom surface 13. The shape of the bottom surface 13 may vary depending on the form of the product and the light-emitting element. In the case of a circular shape, the diameter is defined as the longest length 14, in the case of an elliptical shape, the major axis is defined as the longest length 14, and in the case of a polygon such as a rectangle, the longest diagonal line connecting the vertices of the corners is defined as the longest length 14. Note that the bottom view (lower portion) of the designated area B in Figure 5 excluding the light-emitting element shows an example of a circular shape of the bottom surface 13.

[0064] In a second embodiment of the present invention, Fig. 21 shows an enlarged front cross-sectional view (upper part) of the designated region B in Fig. 20 and a bottom view (lower part) of the designated region B excluding the light-emitting element. In the enlarged front cross-sectional view (upper part) of the designated region B in Fig. 21, 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 extends into the cured film 3 up to a position where it contacts the light-emitting element 2 and the electrode terminal 6 of the light-emitting element 2, and shows the shape of the metal wiring 4 at the contact point.

[0065] The bottom view (lower portion) of designated region B in Figure 21 excluding the light-emitting element is a view from below of the bottom portion 13 of the metal wiring 4 extending to the cured film 3 with the light-emitting element 2 removed, showing the bottom portion 13. The shape of the bottom portion 13 may vary depending on the form of the product and the light-emitting element, and in the case of a circular shape, the diameter is defined as the longest length 14, in the case of an elliptical shape, the major axis is defined as the longest length 14, and in the case of a polygon such as a rectangle, the longest diagonal line connecting the vertices of the corners is defined as the longest length 14. Note that the bottom view (lower portion) of designated region B in Figure 21 excluding the light-emitting element shows an example of a circular shape for the bottom portion 13.

[0066] This configuration allows for the application of minute light-emitting elements and enables high-density packaging of multiple light-emitting elements, resulting in a display device 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. This reduces the unevenness that occurs when stacking the cured film, metal wiring, and light-emitting elements, thereby preventing wiring defects such as wiring shorts and connection defects of the light-emitting elements, thereby reducing the rate of light-emitting defects when used as a display device. Furthermore, it is possible to reduce the height of the display device itself that has light-emitting elements, and shorten the wiring distance to prevent wiring defects such as wiring shorts, reduce loss, and improve high-speed response.

[0067] 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.

[0068] In the first and second embodiments of 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.

[0069] This configuration allows for the application of minute light-emitting elements and enables high-density packaging of multiple light-emitting elements, resulting in a display device 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. This reduces the unevenness that occurs when stacking the cured film, metal wiring, and light-emitting elements, thereby preventing wiring defects such as wiring shorts and connection defects of the light-emitting elements, thereby reducing the rate of light-emitting defects when used as a display device. Furthermore, it is possible to reduce the height of the display device itself that has light-emitting elements, and shorten the wiring distance to prevent wiring defects such as wiring shorts, reduce loss, and improve high-speed response.

[0070] 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.

[0071] In the second embodiment of the present invention, the thickness of the cured film is preferably 1.1 times or more and 4.0 times or less the thickness of the metal wiring.

[0072] The thickness of the metal wiring, as explained in the enlarged front cross-sectional view (upper portion) of designated region B in FIG. 21 , refers to the thickness of the metal wiring 104a arranged on the surface of the cured film 3, and does not include the thickness of the metal wiring 104b 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.

[0073] The thickness of the cured film, when explained with reference to the enlarged front cross-sectional view (upper part) of the designated area B in FIG. 21, refers to the thickness of the cured film 103a that covers the metal wiring 104a.

[0074] 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.

[0075] 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. 20, 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.

[0076] In the first and second aspects of the present invention, the cured film preferably covers the surfaces of the light emitting element other than the light extraction surface.

[0077] As an example of the first aspect of the present invention, Figure 6 shows an enlarged top cross-sectional view (upper part) of the designated area C in Figure 3, a cross-sectional view (middle part) of the designated area C excluding the wiring in a plane perpendicular to the front of the designated area C, and a bottom view (lower part) of the designated area C excluding the opposing substrate.

[0078] In the enlarged top cross-sectional view (upper part) of the designated area C in Figure 6, 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.

[0079] In the cross-sectional view (middle part) of FIG. 6, in which the wiring is removed in a plane perpendicular to the front, it is shown that the periphery of the light emitting element 2 is covered with a cured film 3.

[0080] In the bottom view (lower part) of the designated area C in Figure 6 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.

[0081] As an example of the second aspect of the present invention, Figure 22 shows an enlarged top cross-sectional view (upper part) of the designated area C in Figure 20, a cross-sectional view (middle part) excluding the wiring in a plane perpendicular to the front of the designated area C, and a bottom view (lower part) excluding the opposing substrate of the designated area C.

[0082] In the enlarged top cross-sectional view (upper part) of the designated area C in Figure 22, 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. In the cross-sectional view (middle part) of FIG. 22 in which the wiring is removed in a plane perpendicular to the front, it is shown that the periphery of the light emitting element 2 is covered with a cured film 3.

[0083] In the bottom view (lower part) of the designated area C of Figure 22 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.

[0084] 3, 6, 20, and 22, by covering the entire side surface and top surface of the light-emitting element 2 with the cured film 3, the light-emitting element 2 can be protected from external impact. This is also preferable because it can flatten any steps that arise due to the arrangement of the light-emitting element 2 and also makes it easier to attach the light-emitting element 2 to the opposing substrate 5.

[0085] In the first aspect of the present invention, the cured film 3 covering the surfaces of the light-emitting element 2 other than the light extraction surface has the above-mentioned step flatness, thereby suppressing steps that occur when the cured film, metal wiring, and light-emitting element are stacked, thereby suppressing wiring defects such as short circuits in wiring and connection defects in the light-emitting element, and reducing the rate of defective light emission when used as a display device.

[0086] In the second aspect of the present invention, the cured film 3 covering the surfaces of the light-emitting element 2 other than the light extraction surface has the above-mentioned breakdown voltage, thereby suppressing deterioration of the metal wiring and electrical leakage, and reducing the defect rate even after a reliability test, which is an accelerated test for practical use.

[0087] In the first and second aspects of the present invention, it is preferable to provide a reflective film on the cured film.

[0088] 7, in the first embodiment of the present invention, a reflective film 15 is provided on the cured film 3 disposed around the light-emitting element 2. By providing the reflective film 15 on the cured film 3 described above, the light that has passed through the cured film 3 is reflected by the reflective film 15, thereby increasing the extraction efficiency and improving the brightness.

[0089] In a second embodiment of the present invention, as shown in Fig. 23, a reflective film 15 is provided on the cured film 3 disposed around the light-emitting element 2. By providing the reflective film 15 on the cured film 3, the light that has passed through the cured film 3 is reflected by the reflective film 15, thereby further increasing the extraction efficiency and improving the brightness. In addition, this is preferable because it can suppress deterioration of the metal wiring and the cured film due to water absorption and light in a reliability test, thereby reducing the defect rate.

[0090] The reflective film can be provided at any position on the cured film, and can be disposed so as to surround all four sides in the extraction direction of the light-emitting element, disposed at an angle to the light-emitting element, or disposed with a curve. The reflective film can be any film that reflects light, and examples of the reflective film include, but are not limited to, aluminum, silver, copper, titanium, and alloys containing these.

[0091] In the first and second aspects of the present invention, it is preferable that a partition wall having a thickness equal to or greater than the thickness of the light emitting elements is provided between the plurality of light emitting elements.

[0092] 8, it is preferable that the partition walls 16 are provided in a repeating pattern according to the number of pixels of the display device 1 having the light-emitting elements 2, i.e., between or around each of the light-emitting elements 2. This configuration and a high step flattening rate make it easy to bond the display device to the counter substrate 5, which is preferable.

[0093] 24, in the second embodiment of the present invention, it is preferable to have partition walls 16 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 display device to the counter substrate 5.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] In the first and second aspects of the present invention, it is preferable that a partition wall having a thickness equal to or greater than the thickness of the light emitting elements is disposed between the plurality of light emitting elements in the cured film covering the light emitting elements.

[0099] In the first aspect of the present invention, as another embodiment in which partition walls are provided, a configuration in which partition walls 16 are provided between or around the light-emitting elements 2 in the cured film 3 covering the light-emitting elements 2 is exemplified as shown in FIG.

[0100] In the second aspect of the present invention, as another embodiment in which a partition wall is provided, as shown in Figure 25, a configuration in which a partition wall 16 is provided between or around the light-emitting elements 2 in the cured film 3 covering the light-emitting elements 2 is exemplified.

[0101] 9 and 25 may be made of a material other than the resin composition containing the (A) resin, 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.

[0102] By providing a partition wall, it can be used as a mark when transferring the light-emitting element thereafter, and can also be used as a photospacer, which is preferable because it can increase the efficiency when transferring the light-emitting element.

[0103] It is also preferable to provide a configuration in which partition walls having a thickness equal to or greater than the thickness of the light emitting elements are disposed between the plurality of light emitting elements, and a reflective film is provided around the partition walls.

[0104] 10 and 11, a specific example of the first embodiment of the present invention is a display device 1 having a configuration in which partition walls 16 having a thickness equal to or greater than the thickness of the light-emitting elements 2 are arranged between a plurality of light-emitting elements 2, and a reflective film 15 is provided around the partition walls. By providing a reflective film around the partition walls, light emitted from the light-emitting elements is reflected by the reflective film around the partition walls, thereby increasing the light extraction efficiency and improving the brightness.

[0105] In the second aspect of the present invention, specifically, as shown in Figures 26 and 27, a display device 1 may be configured in which partitions 16 having a thickness greater than or equal to the thickness of the light-emitting elements 2 are arranged between multiple light-emitting elements 2, and a reflective film 15 is provided around the partitions.

[0106] By providing a reflective film around the partition wall, light emitted from the light-emitting element is reflected by the reflective film around the partition wall, which is preferable because it can suppress deterioration of the metal wiring and the cured film due to water absorption and light in a reliability test and reduce the defect rate.

[0107] 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.

[0108] In the first and second embodiments of the present invention, a light diffusing layer may be provided around the light emitting element, the cured film, or the metal wiring.

[0109] In the first and second aspects of the present invention, it is preferable that the light-emitting element is an LED with a side length of 5 μm or more and 700 μm or less, and it is even more preferable that the light-emitting element is an LED with a side length of 5 μm or more and 100 μm or less.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] Known wavelength converting materials can be used.

[0115] 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.

[0116] 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. As the wavelength conversion layer, a known material can be used, and a color filter or the like may also be used as needed.

[0117] 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.

[0118] In the first and second aspects of the present invention, the display device 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.

[0119] In the first aspect of the present invention, a preferred configuration for arranging the driving element is one in which the driving element 8 is arranged in the cured film 3 on the opposing substrate 5 in the vicinity of the light-emitting element 2, as shown in Fig. 12. Also preferred is a configuration in which the driving element 8 is arranged in the cured film (F1) 3a at a position above the light-emitting element 2, as shown in Fig. 13.

[0120] In the second aspect of the present invention, a preferred configuration for arranging the driving element is one in which the driving element 8 is arranged in the cured film 3 on the opposing substrate 5 near the light-emitting element 2, as shown in Fig. 28. Also preferred is a configuration in which the driving element 8 is arranged in the cured film at a position above the light-emitting element 2, as shown in Fig. 29. This makes it possible to suppress wiring defects such as short circuits due to shorter wiring distances, reduce loss, and improve high-speed response.

[0121] In the first and second aspects of the present invention, it is preferable that the display device further comprises a driving element and a substrate, the driving element being connected to the light-emitting elements through the metal wiring, and at least a portion of the metal wiring extending to a side surface of the substrate. By comprising a driving element and a substrate, the driving element being connected to the light-emitting elements through the 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-drive a plurality of light-emitting elements, reduce the height and improve the high-speed response of the display device itself, and further reduce the size and narrow the frame of the display device.

[0122] 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.

[0123] As a configuration of the metal wiring, for example, a configuration as shown in 22 in FIG. 1 or FIG. 3, or 4c in FIG. 20 is preferable.

[0124] In the first and second aspects of the present invention, the metal wiring may be a conductive film, such as 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, although other known conductive films may also be used.

[0125] 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).

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] As a configuration of the conductive film, for example, a configuration as shown in 34 in FIGS. 37 to 40 is preferable.

[0133] In the first and second aspects of 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 light extraction efficiency.

[0134] 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.

[0135] The resin composition containing the (A) resin and the (E) colorant may be given photosensitivity, and the (B) photosensitizer described below may be used.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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 the light extraction efficiency. The thickness of the light-shielding layer is more preferably 4 μm or less.

[0140] 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.

[0141] The reflection chromaticity (L*, a*, b*) of the colored film is obtained by measuring the total reflection chromaticity (SCI) of light incident from a transparent substrate under the measurement conditions of standard illuminant D65 (color temperature 6504K), a viewing angle of 2° (CIE1976), atmospheric pressure, and 20°C using a spectrophotometer (CM-2600d; manufactured by Konica Minolta, Inc.) calibrated with a white calibration plate (CM-A145; manufactured by Konica Minolta, Inc.). The light-shielding layer is preferably arranged as shown in FIG. 41, for example, as 35. The light-shielding layer 35 may be in contact with or spaced apart from the light-emitting element 2.

[0142] In the first aspect of the present invention, in order to obtain the above-mentioned step planarization rate for a cured film obtained by curing a resin composition containing (A) resin, it is preferable that the (A) resin has high heat resistance, specifically, that the resin is less likely to deteriorate or decompose at high temperatures of 160°C or higher during or after heat treatment. Furthermore, such a cured film is preferable because it has a low 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.

[0143] In the second aspect of the present invention, the dielectric breakdown voltage of the cured film obtained by curing the resin composition containing the resin (A) is 360 kV / mm or more and 600 kV / mm or less, which can suppress deterioration of the metal wiring and electrical leakage and reduce the defect rate after reliability testing.

[0144] To obtain such properties, it is preferable that the (A) resin has high heat resistance, specifically, that it is less likely to deteriorate at high temperatures of 160°C or higher during or after heat treatment, and that it is less likely to form, for example, a quinone structure, which is one of the colored structures, due to resin deterioration or decomposition, etc. Furthermore, such a cured film is preferable because it has a low 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] In the first and second aspects of the present invention, 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.

[0150] Polyimide, polyimide precursor, polybenzoxazole, and polybenzoxazole precursor will be described.

[0151] 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.

[0152] Polyimide has a structural unit represented by general formula (1), polyimide precursor and polybenzoxazole precursor have a structural unit represented by the following general formula (2), and 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), the structural unit represented by general formula (3), and the structural unit represented by general formula (7) are copolymerized.

[0153] [ka]

[0154] 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.

[0155] [ka]

[0156] 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.

[0157] [ka]

[0158] In the general formula (3), L and M each independently represent a divalent to octavalent organic group having 4 to 40 carbon atoms.

[0159] [ka]

[0160] In general formula (7), T 1 and U 1 each independently represents a divalent to octavalent organic group having 4 to 40 carbon atoms.

[0161] 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.

[0162] 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.

[0163] In the resin (A), the repeating number n of the structural unit represented by general formula (1), general formula (2), general formula (3), or general formula (7) is preferably 5 to 100,000, and more preferably 10 to 100,000.

[0164] The (A) resin may contain other structural units in addition to the structural units represented by general formula (1), general formula (2), general formula (3), and general formula (7). 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), general formula (2), general formula (3), and general formula (7) are the main structural units. Here, the term "main structural units" refers to structural units represented by general formula (1), general formula (2), general formula (3), and general formula (7) accounting for 50 mol% or more, and more preferably 70 mol% or more, of the total number of structural units.

[0165] In the above general formula (1), V-(R 1 ) a In the above general formula (2), (OH) c -X-(COOR 3 ) e and L in the above general formula (3), T in the above general formula (7). 1 represents an acid residue. V is a tetravalent to decavalent organic group having 4 to 40 carbon atoms, and among these, an organic group having 4 to 40 carbon atoms and containing an aromatic ring or a cyclic aliphatic group is preferred. X, L, and T 1 is a divalent to octavalent organic group having 4 to 40 carbon atoms, and among these, an organic group having 4 to 40 carbon atoms and containing an aromatic ring or an aliphatic group is preferred.

[0166] In the first aspect of the present invention, the polyimide, polyimide precursor, polybenzoxazole, and polybenzoxazole precursor having a structural unit of any one of the general formulae (1) to (3) are free of or contain only a small amount of components that are eliminated during heat treatment, and therefore the change rate in the thickness direction before and after heat treatment is small, at 25% or less. As a result, steps that occur when laminating a cured film, metal wiring, and light-emitting elements are suppressed, the flatness of the steps is improved, wiring defects such as short circuits in wiring and connection defects in light-emitting elements can be suppressed, and the rate of defective light emission when used in a display device can be reduced, which is preferable.

[0167] 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.

[0168] [ka]

[0169] 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.

[0170] These acids can be used as they are, or as acid anhydrides, halides, or activated esters.

[0171] W-(R 2 ) b , (OH) in the above general formula (2) d -Y-(COOR 4 ) f and M in the general formula (3), U in the general formula (7) 1 represents the residue of a diamine. W, Y and M, U 1 is a divalent to octavalent organic group having 4 to 40 carbon atoms, and among these, an organic group having 4 to 40 carbon atoms and containing an aromatic ring or a cycloaliphatic group is preferred.

[0172] 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.

[0173] [ka]

[0174] 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.

[0175] Among these, it is preferred 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.

[0176] [ka]

[0177] 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.

[0178] These diamines can be used as they are, or as diisocyanate compounds or trimethylsilylated diamines obtained by reacting the diamines with phosgene.

[0179] 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.

[0180] [ka]

[0181] 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.

[0182] 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.

[0183] In the first aspect of the present invention, the (A) resin contains a group selected from an alkylene group and an alkylene ether group, which improves the mechanical properties, particularly the elongation, of the (A) resin and a cured film thereof, and improves the light transmittance at 450 nm before and after curing. Furthermore, the group selected from an alkylene group and an alkylene ether group can appropriately lower the glass transition temperature of the (A) resin and impart fluidity, so that a resin film made of a resin composition containing the (A) resin will at least partially flow when heat-treated to form a cured film, improving flatness and suppressing steps that occur when stacking the cured film with metal wiring and light-emitting elements. This can suppress wiring defects such as wiring shorts and connection defects of the light-emitting elements, thereby reducing the rate of light emission defects when used in a display device.

[0184] In the second aspect of the present invention, the (A) resin contains a group selected from an alkylene group and an alkylene ether group, which can improve the mechanical properties, particularly the elongation, of the (A) resin and a cured film thereof, and can also improve the breakdown voltage.

[0185] It is preferable that the (A) resin contains a group selected from the alkylene group and the alkylene ether group as W in the general formula (1) or Y in the general formula (2). 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. Furthermore, in a first aspect of the present invention, the cured film of the resin composition exhibits high chemical resistance due to accelerated ring closure upon low-temperature heat treatment, high adhesion to substrate metals, and resistance to high-temperature humidity test (HAST). In a second aspect of the present invention, the elongation of the (A) resin and its cured film is improved, and further improves the breakdown voltage. Furthermore, in a cured film of the resin composition exhibits high chemical resistance due to accelerated ring closure upon low-temperature heat treatment, high adhesion to substrate metals, and resistance to reliability tests such as high-temperature humidity test (HAST).

[0186] 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).

[0187] These diamines may contain bonds such as -S-, -SO-, -SO2-, -NH-, -NCH3-, -N(CH2CH3)-, -N(CH2CH2CH3)-, -N(CH(CH3)2)-, -COO-, -CONH-, -OCONH-, and -NHCONH-.

[0188] 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. Furthermore, the diamine residues are preferably 40 mol % or less, more preferably 30 mol % or less, of all diamine residues. By achieving the above ranges, in the first aspect of the present invention, the developability in an alkaline developer is improved, and the mechanical properties, particularly elongation, of the (A) resin and its cured film are improved. Furthermore, the transmittance of light at 450 nm after curing can be improved. Furthermore, the cured film of the resin composition can be provided with high chemical resistance, high adhesion to metal surfaces, and resistance to high-temperature and humidity-controlled annealing (HAST) due to the promotion of ring closure upon low-temperature heat treatment. Furthermore, in the second aspect of the present invention, the developability in an alkaline developer is improved, and the elongation of the (A) resin and its cured film is improved, and the breakdown voltage can be improved. Furthermore, the cured film of the resin composition can be provided with high chemical resistance, high adhesion to substrate metals, and resistance to high-temperature and humidity-controlled annealing (HAST) due to the promotion of ring closure upon low-temperature heat treatment.

[0189] 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.

[0190] (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.

[0191] 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.

[0192] 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.

[0193] 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.

[0194] 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.

[0195] In the second embodiment of the present invention, other 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.

[0196] In the first aspect of the present invention, it is preferable that the resin (A) further contains a phenol resin having a biphenyl structure.

[0197] The phenol resin having a biphenyl structure preferably has a structure represented by general formula (5).

[0198] [ka]

[0199] In general formula (5), R 28 , R 29 and R 30 Each represents a monovalent organic group having 1 to 20 carbon atoms. T and U each independently represent an alkylene group or an alkylene oxide group having 1 to 20 carbon atoms. j is an integer of 1 to 3, k 1 , k 2 and k 3 represents an integer of 0 to 2, and l represents an integer of 3 to 100.

[0200] R 28 , R 29 and R 30 Examples of the alkyl group include, but are not limited to, groups selected from a hydroxyl group, a carboxyl group, a sulfonic acid group, and a thiol group, and groups selected from the group consisting of an aliphatic group having 1 to 20 carbon atoms which may have an unsaturated bond, an alicyclic group having 3 to 20 carbon atoms, and an aromatic group having 6 to 20 carbon atoms.

[0201] Although j represents an integer of 1 to 3, j preferably represents an integer of 1 to 2, and more preferably represents an integer of 1, in order to impart appropriate alkali solubility.

[0202] Since the (A) resin contains a phenolic resin having a biphenyl structure, there are no or few components that are eliminated during heat treatment, and therefore the rate of change in the thickness direction before and after heat treatment is small, making it difficult for steps to occur. In addition, the glass transition temperature of the (A) resin can be appropriately lowered to impart fluidity, so that at least a portion of the resin film made of the resin composition containing the (A) resin flows when heat treated to form a cured film, improving the flatness of steps and suppressing steps that occur when the cured film, metal wiring, and light-emitting elements are stacked. This makes it possible to suppress wiring defects such as wiring shorts and connection defects of the light-emitting elements, and reduces the rate of defective light emission when used as a display device.

[0203] The phenolic resin having a biphenyl structure is preferably a resin having the following structure, but is not limited to the following structure.

[0204] [ka]

[0205] In the above formula, n represents an integer of 2 to 99.

[0206] Specific examples of those represented by general formula (5) and the above formula include, but are not limited to, MEHC-7851 series phenolic resins manufactured by Meiwa Kasei Co., Ltd.

[0207] The phenolic resin having a biphenyl structure preferably has a weight-average molecular weight of 700 or more and 50,000 or less. A weight-average molecular weight of 700 or more improves flatness over uneven surfaces, suppresses unevenness caused by stacking the cured film with metal wiring and light-emitting elements, and suppresses wiring defects such as short circuits and connection defects of light-emitting elements, thereby reducing the rate of defective light emission when used in a display device. On the other hand, a weight-average molecular weight of 25,000 or less improves compatibility with one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof, and improves developability with various developers. A weight-average molecular weight of 9,000 or less is even more preferable because it further improves compatibility with one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof.

[0208] The content of the phenolic resin having a biphenyl structure is preferably 5 parts by mass or more, and more preferably 10 parts by mass or more, per 100 parts by mass of one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof, from the viewpoint of improving step flatness. Furthermore, from the viewpoint of compatibility with one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof, the content is preferably 49 parts by mass or less, and more preferably 19 parts by mass or less, per 100 parts by mass of one or more resins selected from the group consisting of polyimide, polyimide precursor, polybenzoxazole, polybenzoxazole precursor, and copolymers thereof.

[0209] In the first embodiment of the present invention, other resins that may 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 any known resins, and may be used alone or in combination.

[0210] In the first and second aspects of the present invention, the resin composition containing (A) resin preferably contains (B) photosensitizer (hereinafter sometimes referred to as component (B)).

[0211] By including the component (B), the resin composition is given photosensitivity, and a fine opening pattern can be formed.

[0212] Component (B) 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 component (B), 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.

[0213] When a photobase generator is contained as component (B), 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.

[0214] When a photopolymerization initiator is contained as component (B), radicals are generated in the irradiated area of ​​the resin composition, which then undergoes radical polymerization, rendering the composition insoluble in an alkaline developer, thereby forming a negative pattern. Furthermore, UV curing during exposure is accelerated, improving sensitivity.

[0215] In the first aspect of the present invention, in order to obtain the above-mentioned step planarization rate for a cured film obtained by curing a resin composition containing resin (A) and component (B), component (B) preferably has high heat resistance and undergoes few structural changes or leaves few groups upon heat treatment.

[0216] In the second aspect of the present invention, the cured film obtained by curing the resin composition containing the resin (A) and the component (B) preferably has a breakdown voltage of 360 kv / mm or more and 600 kv / mm or less, which can suppress deterioration of metal wiring and electrical leakage and reduce the defect rate after reliability testing.

[0217] To achieve such properties, it is preferable that component (B) promotes the reaction with resin (A) and / or thermal crosslinking agent (C), that the decomposition product of component (B) itself reacts with resin (A) and / or thermal crosslinking agent (C), and that the organic acid remaining after heat treatment is minimal. Furthermore, to minimize the organic acid remaining after heat treatment, it is preferable to perform an exposure treatment before curing a resin composition containing component (B). The thermal crosslinking agent (C) is sometimes referred to as component (C).

[0218] From the viewpoint of fine processing ability, the resin composition containing the (A) resin preferably has positive photosensitivity.

[0219] Among the above-mentioned components (B), photoacid generators are preferred from the viewpoint of high sensitivity and fine processability. Examples of photoacid generators include quinone diazide compounds, sulfonium salts, phosphonium salts, diazonium salts, and iodonium salts. Furthermore, a sensitizer or the like may be contained as needed.

[0220] 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.

[0221] 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.

[0222] 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 typical mercury lamp, as well as a broadband including these rays. Also, the (B) component may be incorporated alone or in combination of two or more types, resulting in a highly sensitive resin composition.

[0223] 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.

[0224] 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 first and second aspects of the present invention, the (B-1) compound is preferably included. The (B-1) compound has an absorption spectrum extending into the g-line region of a mercury lamp, making it suitable for g-line and full-wavelength exposure. Furthermore, in the first aspect of the present invention, the (B-1) compound reacts with the (A) resin during curing to form a crosslinked structure, improving chemical resistance. Furthermore, compared with the (B-2) compound, the (B-1) compound contains fewer components eliminated during heat treatment, resulting in reduced stress and shrinkage after heat treatment, making it preferable from the perspective of leveling. The content of the (B-1) compound is preferably 50% by mass or more and 100% by mass or less of the total photosensitizer amount ((B-1) compound + (B-2) compound). This content ratio allows for the production of a cured film with a high level of leveling. In the second aspect of the present invention, the (B-1) compound reacts with the (A) resin and the (C) thermal crosslinking agent during curing to form a crosslinked structure, improving the tensile strength and chemical resistance of the cured film. Furthermore, since less organic acid component remains after heat treatment than the (B-2) compound, this is also preferred from the viewpoint of improving the breakdown voltage. The content of the (B-1) compound is preferably 55% by mass or more and 100% by mass or less of the total amount of the photosensitizer ((B-1) compound + (B-2) compound). This content ratio allows for the production of a cured film with a high breakdown voltage.

[0225] 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.

[0226] The molecular weight of component (B) 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.

[0227] Of the components (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.

[0228] The content of component (B) is preferably 0.1 to 100 parts by mass per 100 parts by mass of resin (A). When the content of component (B) 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.

[0229] When component (B) contains a quinone diazide compound, the content of component (B) is preferably 1 part by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of component (A). 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.

[0230] When component (B) contains a sulfonium salt, phosphonium salt, or diazonium salt, the content of component (B) 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 resin (A). It is also preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and particularly preferably 50 parts by mass or less. An amount of 0.1 to 100 parts by mass can impart photosensitivity while maintaining the heat resistance, chemical resistance, and mechanical properties of the film after heat treatment.

[0231] When a photobase generator is contained as the component (B), specific examples of the photobase generator include amide compounds and ammonium salts.

[0232] 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.

[0233] 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.

[0234] When a photobase generator is contained as component (B), the content of component (B) in the resin composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.7 parts by mass or more, and particularly preferably 1 part by mass or more, relative to 100 parts by mass of resin (A). 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.

[0235] When a photopolymerization initiator is contained as component (B), 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 benzoic acid ester-based photopolymerization initiators, and titanocene-based photopolymerization initiators. Known photopolymerization initiators may be used, or multiple photopolymerization initiators may be used. In the second aspect of the present invention, these are preferred because they promote the reaction with the (A) resin, the (C) thermal crosslinking agent, etc. 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.

[0236] When a photopolymerization initiator is contained as component (B), the content of component (B) in the resin composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.7 parts by mass or more, and particularly preferably 1 part by mass or more, relative to 100 parts by mass of resin (A). A content within the above range can improve sensitivity during exposure. 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. A content within the above range can improve resolution after development.

[0237] In the first and second aspects of the present invention, it is preferred that the resin composition containing the resin (A) further contains a thermal crosslinking agent (C). In the second aspect of the present invention, the inclusion of the component (C) is preferred because it improves the dielectric breakdown voltage and chemical resistance of the cured film.

[0238] A thermal crosslinking agent is a resin or compound that has at least two thermally reactive functional groups in its molecule, such as alkoxymethyl groups, methylol groups, and cyclic ether groups.

[0239] The thermal crosslinking agent may contain one or more compounds selected from alkoxymethyl compounds and methylol compounds (hereinafter, sometimes abbreviated as component (C-1)). The inclusion of component (C-1) strengthens the crosslinking, further improving the chemical resistance of the cured film to, for example, flux solutions. Specific examples of component (C-1) include the following methylol compounds, or alkoxymethyl compounds in which the hydrogen atom of the methylol group is substituted with a methyl group or an alkyl group having 2 to 10 carbon atoms, but are not limited to the structures shown below.

[0240] [ka]

[0241] [ka]

[0242] Component (C) may contain one or more cyclic ether group compounds (hereinafter sometimes referred to as component (C-2)). Component (C-2) allows reaction even at low temperatures of 160°C or less, strengthens crosslinking, increases the dielectric breakdown voltage of the cured film, and further improves the chemical resistance of the cured film.

[0243] Specific examples of the component (C-2) include "Denacol (registered trademark)" EX-212L, Denacol EX-214L, Denacol EX-216L, Denacol EX-850L, and Denacol EX-321L (all manufactured by Nagase ChemteX Corporation), GAN and GOT (all manufactured by Nippon Kayaku Co., Ltd.), "Epikote (registered trademark)" 828, Epicote 1002, Epicote 1750, Epicote 1007, and YX4 000, YX4000H, YX8100-BH30, E1256, E4250, E4275 (all manufactured by Mitsubishi Chemical Corporation), "Epiclon (registered trademark)" 850-S, Epiclon HP-4032, Epiclon HP-7200, Epiclon HP-820, Epiclon HP-4700, Epiclon HP-4770, Epiclon HP4032 (all manufactured by Dainippon Ink and Chemicals, Inc.), TECHMORE Examples of suitable acrylic resins include VG3101L (manufactured by Printec Co., Ltd.), Tepic (registered trademark) S, Tepic G, and Tepic P (manufactured by Nissan Chemical Industries, Ltd.), Epotohto YH-434L (manufactured by Tohto Kasei Co., Ltd.), EPPN502H, NC-3000, NC-6000, and XD-1000 (manufactured by Nippon Kayaku Co., Ltd.), Epiclon N695 and HP7200 (manufactured by Dainippon Ink and Chemicals, Inc.), Etanacol (registered trademark) EHO, Etanacol OXBP, Etanacol OXTP, and Etanacol OXMA (manufactured by Ube Industries, Ltd.), and oxetanized phenol novolac.

[0244] Among them, those having a triarylmethane structure or a biphenyl structure are preferred, Specific examples include YX4000, YX4000H (both manufactured by Mitsubishi Chemical Corporation), TECHMORE VG3101L (manufactured by Printec Co., Ltd.), and NC-3000.

[0245] In the first and second aspects of the present invention, the (C) thermal crosslinking agent preferably contains a thermal crosslinking agent having a biphenyl structure.

[0246] A thermal crosslinking agent is a resin or compound that has at least two thermally reactive functional groups in its molecule, such as alkoxymethyl groups, methylol groups, and cyclic ether groups.

[0247] In the present invention, it is preferable to include the component (C) because this improves chemical resistance.

[0248] The thermal crosslinking agent having a biphenyl structure can appropriately lower the glass transition temperature of the (A) resin, the (B) component, or the resin containing the thermal crosslinking agent having a biphenyl structure, thereby imparting fluidity. Therefore, a resin film made of a resin composition containing the (A) resin, the (B) component, or the thermal crosslinking agent having a biphenyl structure has no or few components that are eliminated during heat treatment, and therefore has a small rate of change in thickness before and after heat treatment, making it difficult for steps to occur. In addition, at least a portion of the resin flows when a cured film is formed by heat treatment, improving the flatness of the steps and suppressing steps that occur when the cured film, metal wiring, and light-emitting elements are stacked. This makes it possible to suppress wiring defects such as wiring shorts and connection defects of the light-emitting elements, and reduces the rate of defective light emission when used as a display device.

[0249] Specific examples of the thermal crosslinking agent having a biphenyl structure include, but are not limited to, the following cyclic ether group compounds, methylol compounds, and alkoxymethyl compounds in which the hydrogen atom of the methylol group is substituted with a methyl group or an alkyl group having 2 to 10 carbon atoms. Copolymers are also possible, and the biphenyl structure may have a substituent.

[0250] [ka]

[0251] [ka]

[0252] n9 represents a repeating unit and represents an integer of 1 to 10.

[0253] In the first and second aspects of the present invention, the component (C) may contain one or more compounds containing a structural unit represented by the following general formula (6) (hereinafter, sometimes abbreviated as component (C-3)):

[0254] [ka]

[0255] In general formula (6), R 25 R is a divalent organic group having an alkylene group or alkylene ether group having 1 to 15 carbon atoms, such as a methylene group, an ethylene group, a propylene group, a butylene group, an ethylene oxide group, a propylene oxide group, or a butylene oxide group, and may be linear, branched, or cyclic. Furthermore, some of the substituents on the divalent organic group having an alkylene group or alkylene ether group having 1 to 15 carbon atoms may have a cyclic ether group, an alkylsilyl group, an alkoxysilyl group, an aryl group, an aryl ether group, a carboxy group, a carbonyl group, an allyl group, a vinyl group, a heterocyclic group, or other substituents, or may be a combination thereof. 26 and R 27 each independently represents a hydrogen atom or a methyl group.

[0256] Because the compound containing the structural unit represented by general formula (6) itself contains a flexible alkylene group and a rigid aromatic group, in the first aspect of the present invention, the compound containing the structural unit represented by general formula (6) can appropriately lower the glass transition temperature of the resin (A), the resin (B), or the resin containing the compound containing the structural unit represented by general formula (6), thereby imparting fluidity. Therefore, when a resin film made from a resin composition containing the resin (A), the resin (B), or the compound containing the structural unit represented by general formula (6) is heated to form a cured film, at least a portion of the resin film flows, improving flatness and suppressing unevenness caused by stacking the cured film with metal wiring and light-emitting elements. This suppresses wiring defects such as wiring shorts and connection defects of light-emitting elements, thereby reducing the rate of light-emitting defects when used in a display device. Furthermore, in the second aspect of the present invention, the resulting cured film has heat resistance while also improving elongation and reducing stress. Examples of crosslinking groups contained in the compound component containing the structural unit represented by general formula (6) include, but are not limited to, acrylic groups, methylol groups, alkoxymethyl groups, and cyclic ether groups. Among these, cyclic ether groups are preferred because they can react with the hydroxyl groups of the (A) resin to improve the heat resistance of the cured film, and can react without dehydration.

[0257] Specific examples of compounds containing a structural unit represented by general formula (6) include, but are not limited to, the following structures.

[0258] [ka]

[0259] During the ceremony o 1 is an integer between 1 and 20, o 2 is an integer of 1 to 5. In order to achieve both heat resistance and improved elongation, 1 is an integer between 3 and 7, o 2 is preferably an integer of 1 to 2.

[0260] In the first embodiment of the present invention, known cyclic ether group compounds, alkoxymethyl compounds and methylol compounds may be contained as thermal crosslinking agents other than the above-mentioned thermal crosslinking agents.

[0261] The component (C) may contain two or more types in combination.

[0262] In the first and second aspects of the present invention, the content of component (C) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, per 100 parts by mass of the (A) resin, from the viewpoint of obtaining a cured film with high chemical resistance to, for example, fluxing liquid, while maintaining the storage stability of the resin composition. Furthermore, from the viewpoint of being able to obtain a cured film with high chemical resistance to, for example, fluxing liquid, and further being able to suppress peeling from the metal wiring and cracking of the cured film after reliability testing of wiring to which the cured film is applied, the content is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 80 parts by mass or less, per 100 parts by mass of the (A) resin.

[0263] In the first aspect of the present invention, when the total amount of the thermal crosslinking agent (C) is taken as 100 parts by mass, the content ratio of the thermal crosslinking agent having a biphenyl structure which may have a substituent and the thermal crosslinking agent having a structural unit represented by general formula (14) is preferably 15 parts by mass or more and 80 parts by mass or less. This improves flatness of steps, suppresses steps caused by laminating the cured film, metal wiring, and light-emitting elements, and can suppress wiring defects such as wiring short circuits and connection defects of light-emitting elements, thereby reducing the rate of light-emission defects when used in a display device.

[0264] In the first and second aspects of the present invention, the resin composition containing the (A) resin may contain, as necessary, other components such as a radically polymerizable compound, an antioxidant, a solvent, a compound having a phenolic hydroxyl group, an adhesion improver, a bonding improver, and a surfactant.

[0265] Next, a method for producing a resin composition according to the first and second aspects of the present invention will be described. For example, the resin (A) can be obtained by mixing and dissolving the (B) component, the (C) component, each radical polymerizable compound, an antioxidant, a solvent, a compound having a phenolic hydroxyl group, an adhesion improver, a bonding improver, a surfactant, and the like, as needed.

[0266] The dissolution method may be a known method such as heating or stirring.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] 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.

[0271] 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.

[0272] Next, a method for manufacturing the display device of the present invention will be described.

[0273] First, a method for manufacturing a display device according to the first aspect of the present invention will be described.

[0274] FIG. 14 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 first embodiment of the present invention.

[0275] 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. The term "cured film" refers to a resin film or a film obtained by curing a resin sheet.

[0276] FIG. 14a shows a process of placing a light-emitting element 2 having a pair of electrode terminals 6 on a support substrate 20. 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 this process, and after removal, another opposing substrate may be disposed.

[0277] Next, Figure 14b shows a process of forming a resin film 21 by applying or laminating a resin composition containing (A) resin or a resin sheet formed from a resin composition containing (A) resin onto the support substrate 20 and the light-emitting element 2.

[0278] 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, a reflective film, or a partition wall.

[0279] 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.

[0280] 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.

[0281] Next, the coated film of the resin composition containing the (A) resin is dried to obtain the resin film 21. Drying is preferably carried out using an oven, a hot plate, infrared rays, or the like at a temperature in the range of 50°C to 140°C for one minute to several hours.

[0282] On the other hand, when the resin sheet is used, if the resin sheet has a protective film, the protective film is peeled off, and the resin sheet and a support substrate are placed opposite each other and bonded together by thermocompression (placing the resin sheet and the support substrate opposite each other and bonding them together by thermocompression is sometimes referred to as laminating the resin sheet to the support substrate). Next, the resin sheet laminated to the support substrate is dried in the same manner as when obtaining the resin film, to form resin film 21. The resin sheet can be obtained by applying a resin composition containing resin (A) to a support film made of polyethylene terephthalate or the like, which is a peelable substrate, and drying the applied composition.

[0283] 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.

[0284] Next, FIG. 14c shows a process of forming a penetrating opening pattern 12 corresponding to the shape of the metal wiring 4 in the resin film 21 using a photolithography process. (A) A resin composition or resin sheet containing the resin can be microfabricated, allowing for high-density arrangement of light-emitting elements.

[0285] 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.

[0286] The exposed photosensitive resin film 21 is developed. Preferred developer 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.

[0287] Next, FIG. 14c shows a step of forming a cured film 3 by curing the resin film 21.

[0288] The resin film 21 is heated to promote a ring-closing reaction or a thermal crosslinking reaction, thereby obtaining a cured film 3. The cured film 3 has improved heat resistance and chemical resistance due to crosslinking between components (A) themselves or between components (B) and (C). 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. 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. Furthermore, to provide an excellent cured film, improve the reliability of display devices, and further improve the flatness of steps after heat treatment, the heat treatment temperature is preferably 300°C or lower, more preferably 250°C or lower.

[0289] To obtain a highly reliable cured film, heating is preferably carried out in an atmosphere with a low oxygen concentration, preferably 1000 ppm or less, more preferably 300 ppm or less, and even more preferably 50 ppm or less.

[0290] 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.

[0291] Fig. 42 shows a front cross-sectional view of the opening pattern of the cured film. In Fig. 42, the angle of the inclined side 36 of the opening pattern formed in the cured film 3 is 37. The inclined side is a straight line connecting the opening pattern at a position 39 that is halfway in the thickness direction of the cured film 3 and the opening pattern at the bottom.

[0292] Next, in FIG. 14c, in order to improve the adhesion between the cured film 3 and the metal wiring (K1) 4a and the metal wiring (K2) 4b, 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.

[0293] 14d shows a process in which, after forming a photoresist layer (not shown), metal wiring (K1) 4a made of copper or the like is formed in the opening pattern 12 of the cured film 3 by plating or the like to electrically connect to a pair of electrode terminals 6 of the light-emitting element 2, and metal wiring (K2) 4b is formed on a part of the surface of the cured film 3. Thereafter, unnecessary photoresist, seed layer, and barrier metal are removed.

[0294] As a result, the cured film can ensure electrical insulation of the metal wiring, and by extending the metal wiring through the cured film, a pair of electrode terminals of the light-emitting element and the driving element can be electrically connected, thereby controlling the light-emitting operation. Furthermore, since the cured film in contact with a part of the surface of the metal wiring has high step flatness, the cured film also functions as an insulating film or protective film for the appropriate metal wiring, and in the display device, steps caused by stacking the cured film, metal wiring, and light-emitting element can be suppressed, and wiring defects such as wiring shorts and connection defects of the light-emitting element can be suppressed, thereby reducing the rate of light-emitting defects when used as a display device.

[0295] The method for producing a display device of the present invention may include a step of forming a plurality of layers of the cured film having metal wiring therein.

[0296] As shown in FIGS. 14e to 14f, the cured film (F1) 3a, metal wiring (K1) 4a, and metal wiring (K2) 4b can be formed by repeating the same method again to form a cured film 3a consisting of two or more layers.

[0297] This suppresses steps that occur when the cured film, metal wiring, and light-emitting elements are stacked, and it is possible to suppress wiring defects such as wiring shorts and connection defects of the light-emitting elements, thereby reducing the rate of light emission defects when used as a display device. Furthermore, by forming multiple layers of cured films having metal wiring in the cured film, it is possible to arrange multiple light-emitting elements, and it is possible to suppress wiring defects such as wiring shorts due to a low package height and a short wiring distance, reduce loss, and improve high-speed response.

[0298] Thereafter, as shown in FIG. 14g, a barrier metal 9 is formed in the opening pattern 12 of the cured film (F1) 3a by sputtering, 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.

[0299] 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. 14. In this case, the driving elements are electrically connected to the light-emitting element 2 via the metal wiring (K1) 4a and the metal wiring (K2) 4b extending into the cured film 3 and the cured film (F1) 3a.

[0300] 14h, 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 20 is peeled off, and an 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.

[0301] As a result, the cured film can ensure electrical insulation of the metal wiring, and by extending the metal wiring into the cured film, a pair of electrode terminals of the light-emitting element and the driving element can be electrically connected, thereby controlling the light-emitting operation. Furthermore, the high level of flatness of the cured film suppresses steps that occur when the cured film, metal wiring, and light-emitting element are stacked, thereby suppressing wiring defects such as wiring shorts and connection defects of the light-emitting element, and reducing the rate of light-emitting defects when used as a display device.

[0302] The metal wiring 4 may be replaced with a conductive film 34. Figure 49 shows a process in which a conductive film 34 is used instead of the metal wiring 4.

[0303] After the step of forming a penetrating opening pattern 12 corresponding to the shape of the metal wiring 4 using a photolithography process, and before the step of curing the resin film 21, a step of exposing the entire area of ​​the resin film may be included. By exposing the film after development, coloring during heat treatment can be suppressed and the transmittance of light with a wavelength of 450 nm after heat treatment can be improved, which is particularly preferable when a photoacid generator is used as component (B).

[0304] In the manufacturing method of the display device according to the first aspect of the present invention, a step of providing a partition wall having a thickness equal to or greater than the thickness of the light-emitting element may be included before the step of arranging the light-emitting element 2 having a pair of electrode terminals 6 on the support substrate 20.

[0305] FIG. 15a shows a process of providing partition walls 16 having a thickness equal to or greater than that of the light-emitting element 2 on a support substrate, and the next FIG. 15b shows a process of providing a plurality of light-emitting elements 2 between partition walls having a thickness equal to or greater than that of the light-emitting element 2. FIG. 15c shows a process of disposing a resin film 21, similar to the process shown in FIG. 14b, while the partition walls 16 remain in place. The subsequent processes are carried out as shown in FIG. 14. The partition walls may be made of (A) resin, or known materials such as epoxy resin, (meth)acrylic polymer, polyurethane, polyester, polyolefin, and polysiloxane. Light-shielding and reflective portions may also be provided.

[0306] The method for manufacturing a display device according to the first aspect of the present invention may include, after the step of curing the resin film 21, a step of providing a reflective film on a part of the cured film. An example of a process for providing a reflective film on a portion of the cured film is shown in Fig. 16. Fig. 16d shows a process for providing a reflective film 15 on a partial region of the cured film 3.

[0307] The steps up to Figure 16d are the same as those up to Figure 14c, and the next step in Figure 16e shows the same process of forming metal wiring (K1) 4a and metal wiring (K2) 4b as in Figure 14d. The subsequent steps are carried out in the order of the steps shown in Figure 14, with the reflective film 15 remaining in place. The reflective film is formed by a method such as sputtering using aluminum, silver, copper, titanium, or an alloy containing any of these. It is also preferable to protect the relevant parts in advance with photoresist or the like, or to perform sputtering using a specified mask, so that they do not overlap with the metal wiring to be formed later.

[0308] In the manufacturing method of the display device of the first aspect of the present invention, after the step of forming metal wiring (K1) 4a made of copper or the like in the opening pattern 12 of the cured film 3 by a plating method or the like for electrically connecting to a pair of electrode terminals 6 of the light-emitting element 2 and forming metal wiring (K2) 4b on a part of the surface of the cured film 3, it is preferable to further include a step of having a driving element and a substrate, the driving element being connected to the light-emitting element through metal wiring, and at least a part of the metal wiring extending to a side surface of the substrate.

[0309] Figure 14h shows a process in which the driving element and substrate are connected to the light-emitting element through metal wiring. As shown in Figure 14h, the driving element 8 is connected to the light-emitting element 2 through metal wiring 4 and 22, and part of the metal wiring 22 extends to the side of the light-emitting element driving substrate 7. If the light-emitting element driving substrate 7 has a through electrode, the driving element 8 may be connected through the through electrode.

[0310] 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.

[0311] The metal wiring 22 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.

[0312] In the method for manufacturing a display device according to the first aspect of the present invention, the metal wiring may be a conductive film.

[0313] In FIG. 43h, the driving element is connected to the light emitting element 2 through the metal wiring 4 and the conductive film 34, and a part of the conductive film 34 extends to the side surface of the light emitting element driving substrate 7.

[0314] The conductive film 34 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.

[0315] The method for manufacturing a display device according to the first aspect of the present invention preferably further comprises the step of providing a light-shielding layer between the plurality of light-emitting elements.

[0316] 44a shows a process of providing a light-shielding layer 35 between a plurality of light-emitting elements 2. The light-shielding layer 35 may be formed before or after the light-emitting elements 2 are formed.

[0317] The light-shielding layer 35 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.

[0318] The resin composition containing the (A) resin and the (E) colorant may be given photosensitivity, and the (B) photosensitizer described below may be used.

[0319] 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.

[0320] Figure 17 shows cross-sectional views of the manufacturing process of another embodiment of the display device 1 according to the first aspect of the present invention. The steps overlap with those in Figure 14, specifically Figures 17b to 17e overlap with Figures 14b to 14f, so their explanations are omitted.

[0321] 17a shows a process of arranging metal wiring (K2) 4b on a support substrate 20. The metal wiring (K2) 4b may be made of copper or aluminum, and may be used as an electrode pad.

[0322] Next, FIG. 17b shows a process of forming a resin film 21 by applying or laminating a resin composition or a resin sheet containing (A) resin onto the support substrate 20 and the metal wiring (K2) 4b.

[0323] Note that "on the support substrate and on the metal wiring (K2) 4b" does not only mean the surface of the support substrate and the surface of the metal wiring (K2) 4b, but also means the upper side of the support substrate and the metal wiring (K2) 4b, 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, reflective film, or partition wall.

[0324] Next, FIG. 17c shows a process of forming a plurality of penetrating opening patterns 12 in the resin film 21 using a photolithography process.

[0325] Next, FIG. 17c shows a process of curing the resin film 21 to form a cured film (F1) 3a.

[0326] Next, in FIG. 17c, in order to improve the adhesion between the cured film (F1) 3a and the metal wiring (K1) 4a and the metal wiring (K2) 4b, a barrier metal such as titanium is sputtered onto the cured film (F1) 3a, and a copper seed (seed layer) is further formed on top of that by sputtering.

[0327] 17d shows a process in which a photoresist layer (not shown) is formed, and then metal wiring (K1) 4a made of copper or the like is formed in the opening pattern 12 of the cured film (F1) 3a by plating or the like, and the metal wiring (K2) 4b is formed on a part of the surface of the cured film (F1) 3a. Thereafter, unnecessary photoresist, the seed layer, and the barrier metal are removed.

[0328] As a result, the cured film can ensure electrical insulation of the metal wiring, and by extending the metal wiring through the cured film, a pair of electrode terminals of the light-emitting element and the driving element can be electrically connected, thereby controlling the light-emitting operation. Furthermore, since the cured film in contact with a part of the surface of the metal wiring has high step flatness, the cured film also functions as an insulating film or protective film for the appropriate metal wiring, and in the display device, steps caused by stacking the cured film, metal wiring, and light-emitting element can be suppressed, and wiring defects such as wiring shorts and connection defects of the light-emitting element can be suppressed, thereby reducing the rate of light-emitting defects when used as a display device.

[0329] The method for producing a display device according to the first aspect of the present invention may further include a step of forming a plurality of layers of the cured film having the metal wiring therein. By repeating the same method again on the cured film (F1) 3a and the metal wiring (K2) 4b, a cured film (F1) 3a consisting of two or more layers can be formed as shown in FIG. 17e.

[0330] This suppresses steps that occur when the cured film, metal wiring, and light-emitting elements are stacked, and it is possible to suppress wiring defects such as wiring shorts and connection defects of the light-emitting elements, thereby reducing the rate of light emission defects when used as a display device. Furthermore, by forming multiple layers of cured films having metal wiring in the cured film, it is possible to arrange multiple light-emitting elements, and it is possible to suppress wiring defects such as wiring shorts due to a low package height and a short wiring distance, reduce loss, and improve high-speed response.

[0331] 17f shows a process of disposing the light-emitting element 2 on the cured film 3 so as to maintain electrical connection with the metal wiring 4. The electrode terminal 6 of the light-emitting element 2 and the metal wiring 4 may be connected directly or via, for example, a solder ball.

[0332] As shown in FIG. 17g, a step of forming a cured film 29 on the cured film 3a and the light-emitting element 2 may be included. The cured film 29 is preferably formed by applying a resin composition containing the (A) resin or laminating a resin sheet made of the resin composition containing the (A) resin to form a resin film made of the resin composition, and then curing the resin film to form the cured film 29. Furthermore, the cured film 29 may 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.

[0333] The curing conditions vary depending on the type of resin, but examples include 80°C to 230°C and 15 minutes to 5 hours.

[0334] This is intended to protect and flatten the light emitting element by forming a cured film on the light emitting element.

[0335] 17h shows a process of bonding the opposing substrate 5 to the light-emitting element 2 and the cured film 29 using an adhesive or the like. Then, the support substrate 20 is peeled off, and a barrier metal 9 and bumps 10 are formed, which are 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.

[0336] The driving element 8 is electrically connected to the light-emitting element 2 via the metal wiring 22 and the metal wiring (K1) 4a and metal wiring (K2) 4b extending into the cured film (F1) 3a, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. The metal wiring 4 may include an electrode.

[0337] As a result, the cured film can ensure electrical insulation of the metal wiring, and by extending the metal wiring through the cured film, a pair of electrode terminals of the light-emitting element and the driving element can be electrically connected, thereby controlling the light-emitting operation. Furthermore, the high step flattening rate of the cured film suppresses steps that occur when the cured film, metal wiring, and light-emitting element are stacked, thereby suppressing wiring defects such as wiring shorts and connection defects of the light-emitting element, and reducing the rate of light-emitting defects when used as a display device.

[0338] The metal wiring 4 may be replaced with a conductive film 34. Figure 50 shows a process in which a conductive film 34 is used instead of the metal wiring 4.

[0339] After the step of forming a through-hole pattern 12 corresponding to the shape of the metal wiring 4 using a photolithography process, and before the step of curing the resin film 21, a step of exposing the entire area of ​​the resin layer to light may be included.

[0340] By exposing the resin layer after development, coloring during heat treatment can be suppressed and the transmittance of light with a wavelength of 450 nm after heat treatment can be improved, which is particularly preferred when a photoacid generator is used as component (B).

[0341] In the manufacturing method of the display device according to the first aspect of the present invention, it is preferable to include a step of providing a partition wall having a thickness equal to or greater than the thickness of the light-emitting element before the step of arranging the light-emitting element 2 on the cured film 3 so as to maintain electrical connection with the metal wiring 4.

[0342] Figure 18f shows a process of forming multiple layers of the cured film 3a shown in Figure 17e and then providing partition walls 16. Thereafter, as shown in Figure 18g, the light-emitting element 2 is provided between the partition walls 16, and then, as shown in Figure 18h, the opposing substrate 5 is attached to the upper part of the partition walls 16 and the light-emitting element 2, the support substrate 20 is peeled off, and barrier metal 9 and bumps 10 are formed, and the substrate is electrically connected via the solder bumps 10 to a light-emitting element drive substrate 7 having drive elements 8 such as a driver IC.

[0343] In the manufacturing method of the display device according to the first aspect of the present invention, it is preferable to have a step of providing a reflective film on a part of the cured film before the step of arranging the light-emitting element 2 on the cured film 3 so as to maintain electrical connection with the metal wiring 4.

[0344] Fig. 19f shows a process of forming a reflective film 15 after forming multiple layers of the cured film 3a shown in Fig. 17e. The subsequent processes are carried out in the order of the processes shown in Fig. 17f, Fig. 17g, and Fig. 17h, with the reflective film 15 remaining in place.

[0345] In the manufacturing method of the display device of the first aspect of the present invention, after the step of forming the cured film 29 on the cured film 3 and the light-emitting element 2, it is preferable to further include a step of having a driving element and a substrate, the driving element being connected to the light-emitting element through metal wiring, and at least a part of the metal wiring extending to the side surface of the substrate.

[0346] Figure 17h shows a process in which the driving element and substrate are connected to the light-emitting element through metal wiring. As shown in Figure 17h, the driving element 8 is connected to the light-emitting element 2 through metal wiring 4 and 22, and part of the metal wiring 22 extends to the side of the light-emitting element driving substrate 7. If the light-emitting element driving substrate 7 has a through electrode, the driving element 8 may be connected through the through electrode.

[0347] 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.

[0348] The metal wiring 22 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.

[0349] In the method for manufacturing a display device according to the first aspect of the present invention, the metal wiring may be a conductive film.

[0350] In FIG. 45h, the driving element is connected to the light emitting element 2 through the metal wiring 4 and the conductive film 34, and a part of the conductive film 34 extends to the side surface of the light emitting element driving substrate 7.

[0351] The conductive film 34 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.

[0352] FIG. 46 shows cross-sectional views illustrating the manufacturing process of another embodiment of the display device 1 according to the first aspect of the present invention.

[0353] 46a shows a process for forming a resin film made of a resin composition containing (A) resin on a substrate, etc. The resin film may be formed by applying or laminating a resin composition containing (A) resin or a resin sheet formed from a resin composition containing (A) resin.

[0354] The substrate can be a light emitting element driving substrate 7. Figure 46a shows an example of a TFT array substrate in which TFTs 30, an insulating film 31, and metal wiring 4 are arranged on a glass substrate.

[0355] Examples of the metal wiring 4 include gold, silver, copper, aluminum, nickel, titanium, molybdenum, and alloys containing these. Examples of the insulating film 31 include, but are not limited to, a silicon oxide film, a silicon nitride film, and an insulating film made of an organic material.

[0356] The next step is to form a pattern of a plurality of openings penetrating the resin film using a photolithography process.

[0357] The next step is to form a hardened film 3 by hardening the resin film.

[0358] 46b shows a process of forming 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. After forming a photoresist layer (not shown), wiring 32 is formed on a portion of the surface of the cured film 3 by, for example, a sputtering method. Thereafter, unnecessary photoresist is removed.

[0359] Examples of wiring 32 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 materials may also be used.

[0360] The first aspect of the present invention may include a step of forming a plurality of layers of the cured film having metal wiring therein.

[0361] 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. 46c.

[0362] Next, Fig. 46d shows a process of disposing the light-emitting element 2 on the cured film 3 so as to maintain electrical connection with the wiring 32. The electrode terminal 6 of the light-emitting element 2 and the wiring 32 may be connected directly or via, for example, a solder ball.

[0363] Moreover, the partition wall 16 may be formed before or after the light emitting element 2 is disposed.

[0364] Thereafter, as shown in Fig. 46e, an opposing substrate 5 is attached using an adhesive or the like. A conductive film 34 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 34 via the metal wiring 4 and wiring 32 extending into the cured film 3, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. The wiring 32 also includes electrodes.

[0365] As a result, the cured film can ensure electrical insulation of the metal wiring, and by extending the metal wiring through the cured film, a pair of electrode terminals of the light-emitting element and the driving element can be electrically connected, thereby controlling the light-emitting operation. Furthermore, the high step flattening rate of the cured film suppresses steps that occur when the cured film, metal wiring, and light-emitting element are stacked, thereby suppressing wiring defects such as wiring shorts and connection defects of the light-emitting element, and reducing the rate of light-emitting defects when used as a display device.

[0366] Next, a method for manufacturing a display device according to the second embodiment of the present invention will be described.

[0367] A method for manufacturing a display device according to a second aspect 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 support substrate; (D2) forming a resin film made of a resin composition containing (A) resin on the support substrate and the light-emitting elements; (D3) exposing and developing the resin film to form a pattern of a plurality of through-holes in the resin film; (D4) curing the resin film to form the cured film having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less; 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. Figure 30 shows cross-sectional views of an example of the manufacturing process of a display device having a plurality of light-emitting elements according to the second aspect of the present invention. 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. The term "cured film" refers to a resin film or a film obtained by curing a resin sheet.

[0368] In FIG. 30a, step (D1) is a step of arranging a light-emitting element 2 having a pair of electrode terminals 6 on a support substrate 20. 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.

[0369] Next, step (D2) is a step of forming a resin film 21 by applying or laminating a resin composition containing (A) resin or a resin sheet formed from a resin composition containing (A) resin onto the support substrate 20 and the light-emitting element 2, as shown in Figure 30b.

[0370] 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, a reflective film, or a partition wall.

[0371] 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.

[0372] 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.

[0373] Next, the coated film of the resin composition containing the (A) resin is dried to obtain the resin film 21. Drying is preferably carried out using an oven, a hot plate, infrared rays, or the like at a temperature in the range of 50°C to 140°C for one minute to several hours.

[0374] On the other hand, when the resin sheet is used, if the resin sheet has a protective film, the protective film is peeled off, and the resin sheet and a support substrate are placed opposite each other and bonded together by thermocompression (placing the resin sheet and the support substrate opposite each other and bonding them together by thermocompression is sometimes referred to as laminating the resin sheet to the support substrate). Next, the resin sheet laminated to the support substrate is dried in the same manner as when obtaining the resin film, to form resin film 21. The resin sheet can be obtained by applying a resin composition containing resin (A) to a support film made of polyethylene terephthalate or the like, which is a peelable substrate, and drying the applied composition.

[0375] 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.

[0376] Next, in step (D3), as shown in FIG. 30c, a penetrating opening pattern 12 corresponding to the shape of the metal wiring 4 is formed in the resin film 21 using a photolithography process. (A) A resin composition or resin sheet containing the resin can be microfabricated, allowing for high-density arrangement of light-emitting elements.

[0377] 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.

[0378] The exposed photosensitive resin film 21 is developed. Preferred developer 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.

[0379] Next, as shown in FIG. 30c, the step (D4) is a step of curing the resin film 21 to form a cured film 3 having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less.

[0380] The resin film 21 is heated to promote ring-closing reactions and thermal crosslinking reactions, yielding a cured film 3. The cured film 3 exhibits improved breakdown voltage, heat resistance, and chemical resistance due to crosslinking between components (A) themselves or with components (B) and (C). 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. An example includes 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. Furthermore, 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.

[0381] To obtain a cured film with high light transmittance, heating is preferably carried out in an atmosphere with a low oxygen concentration, preferably 1000 ppm or less, more preferably 300 ppm or less, and even more preferably 50 ppm or less.

[0382] 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.

[0383] Fig. 42 shows a front cross-sectional view of the opening pattern of the cured film. In Fig. 42, the angle of the inclined side 36 of the opening pattern formed in the cured film 3 is 37. The inclined side is a straight line connecting the opening pattern at a position 39 that is halfway in the thickness direction of the cured film 3 and the opening pattern at the bottom.

[0384] Next, in FIG. 30c, 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 thereon by sputtering.

[0385] Next, in step (D5), as shown in Fig. 30d, 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.

[0386] This allows the cured film to ensure electrical insulation of the metal wiring, and extending the metal wiring through the cured film electrically connects a pair of electrode terminals of the light-emitting element to the driving element, thereby controlling light-emitting operation. Furthermore, the cured film has high light transmittance, which can suppress absorption of light emitted from the light-emitting element, thereby improving light extraction.

[0387] In the method for producing a display device according to the second aspect of the present invention, it is preferable to include a step of repeating the steps (D2), (D3), (D4) and (D5) multiple times to form multiple layers of the cured film having the metal wiring therein.

[0388] As shown in FIGS. 30e to 30f, 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.

[0389] 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.

[0390] Thereafter, as shown in FIG. 30g, a barrier metal 9 is formed in the opening pattern 12 of the cured film 3 by sputtering, 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.

[0391] 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. 30. 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.

[0392] 30h, 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 20 is peeled off, and the opposing substrate 5 is attached using an adhesive or the like to obtain a display device 1 having a plurality of light-emitting elements 2. The metal wiring 4 may include electrodes.

[0393] This allows the cured film to ensure electrical insulation of the metal wiring, and by extending the metal wiring into 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.

[0394] The metal wiring 4 may be replaced with a conductive film 34. Figure 51 shows a process in which a conductive film 34 is used instead of the metal wiring 4.

[0395] The method for manufacturing a display device according to the second aspect of the present invention may include, after the step (D3) and before the step (D4), a step (D6) of exposing the entire region of the resin film to light. By exposing the film to light after development, the amount of organic acid remaining after heat treatment can be reduced, thereby improving the breakdown voltage, which is particularly preferable when a photoacid generator is used as component (B).

[0396] In the method for manufacturing a display device according to the second aspect of the present invention, it is preferable to have, after the step (D1), a step (D7) of providing partition walls between a plurality of the light-emitting elements, the partition walls having a thickness equal to or greater than the thickness of the light-emitting elements.

[0397] An example of step (D7) is shown in Figure 31. Figure 31a shows step (D7) of providing partition walls 16 having a thickness equal to or greater than that of the light-emitting element 2 on a support substrate, and the following Figure 31b 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 31c shows a step of disposing a resin film 21, similar to step (D2) shown in Figure 30b, while leaving the partition walls 16 in place. The subsequent steps are carried out as shown in Figure 30. The partition walls may be made of (A) resin, or known materials such as epoxy resin, (meth)acrylic polymer, polyurethane, polyester, polyolefin, and polysiloxane. Light-shielding and reflective portions may also be provided.

[0398] In the method for producing a display device according to the second aspect of the present invention, it is preferable to have, after the step (D4), a step (D8) of providing a reflective film on a part of the cured film.

[0399] An example of step (D8) is shown in Figure 32. Figure 32d shows step (D8) of providing a reflective film 15 on a partial area of ​​the cured film 3.

[0400] The steps up to Figure 32d are the same as those up to step (D4) in Figure 30c, and the next step in Figure 32e shows step (D5) of forming metal wiring 4, the same as in Figure 30d. The subsequent steps are carried out in the order of the steps shown in Figure 30, with reflective film 15 remaining in place. The reflective film is formed by a method such as sputtering using aluminum, silver, copper, titanium, or an alloy containing any of these. It is also preferable to protect the relevant parts in advance with photoresist or the like, or to perform sputtering using a specified mask, so that they do not overlap with the metal wiring to be formed later.

[0401] In the manufacturing method of the display device of the second aspect of the present invention, after the step (D5), it is preferable to further include a step (D9) of having a driving element and a substrate, the driving element being connected to the light-emitting element through metal wiring, and at least a part of the metal wiring extending to the side of the substrate.

[0402] An example of step (D9) is shown in Figure 30. Figure 30h shows step (D9) 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 30h, the driving element 8 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, the driving element 8 may be connected through the through electrode.

[0403] 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.

[0404] 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.

[0405] In the method for manufacturing a display device according to the second aspect of the present invention, the metal wiring may be a conductive film (D10).

[0406] An example of step (D10) is shown in Fig. 43. In Fig. 43h, the driving element is connected to the light emitting element 2 through the metal wiring 4 and the conductive film 34, and part of the conductive film 34 extends to the side surface of the light emitting element driving substrate 7.

[0407] 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.

[0408] The conductive film 34 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.

[0409] The method for producing a display device according to the second aspect of the present invention preferably further comprises the step (D11) of providing a light-shielding layer between the plurality of light-emitting elements.

[0410] An example of step (D11) is shown in Figure 44. Figure 44a shows step (D11) of providing a light-shielding layer 35 between multiple light-emitting elements 2. The light-shielding layer 35 may be formed before or after the light-emitting elements 2 are formed.

[0411] The light-shielding layer 35 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.

[0412] The resin composition containing the (A) resin and the (E) colorant may be given photosensitivity, and the (B) photosensitizer described below may be used.

[0413] 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.

[0414] Furthermore, a second aspect of the present invention provides 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 the steps of: (E1) arranging metal pads on a supporting substrate; (E2) forming a resin film made of a resin composition containing (A) resin on the supporting 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; (E4) curing the resin film to form the cured film having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less; (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.

[0415] Figure 33 shows cross-sectional views of the manufacturing process of another embodiment of the display device 1 of the present invention. The steps overlap with those in Figure 30, specifically Figures 33b to 33e overlap with Figures 30b to 30f, so their explanations are omitted.

[0416] Step (E1) is a step of arranging metal pads 18 on a support substrate 20, as shown in FIG. 33a.

[0417] The metal pad may be made of copper or aluminum.

[0418] Next, in step (E2), as shown in FIG. 33b, a resin composition or a resin sheet containing (A) resin is applied or laminated onto support substrate 20 and metal pads 18 to form resin film 21.

[0419] 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, a reflective film, or a partition wall.

[0420] Next, in the step (E3), as shown in FIG. 33c, a plurality of penetrating opening patterns 12 are formed in the resin film 21 using a photolithography process.

[0421] Next, as shown in FIG. 33c, the step (E4) is a step of forming a cured film 3 having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less by curing the resin film 21.

[0422] Next, in FIG. 33c, in order to improve the 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 thereon by sputtering.

[0423] Next, in step (E5), as shown in Fig. 33d, 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.

[0424] In the method for producing a display device according to the second aspect of the present invention, it is preferable to include a step of repeating the steps (E2), (E3), (E4) and (E5) multiple times to form multiple layers of the cured film having the metal wiring therein.

[0425] As shown in FIGS. 33b to 33d, the cured film 3 and the metal wiring 4 can be repeatedly formed in the same manner to form a cured film 3 consisting of two or more layers as shown in FIG. 33e.

[0426] Next, in step (E6), as shown in Fig. 33f, the light-emitting element 2 is disposed on the cured film 3 so as to maintain electrical connection with the metal wiring 4. The electrode terminal 6 of the light-emitting element 2 and the metal wiring 4 may be connected directly or via, for example, a solder ball.

[0427] As shown in Fig. 33g, it is preferable to have a step (E7) of forming a cured film 29 on the cured film 3 and the light-emitting element 2. It is preferable to form the cured film 29 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 29. Furthermore, the cured film may be made of a material other than the resin composition containing the (A) resin and the (B) photosensitizer, and known materials such as epoxy resin, silicone resin, and fluororesin may also be used.

[0428] The curing conditions vary depending on the type of resin, but examples include 80°C to 230°C and 15 minutes to 5 hours.

[0429] This is intended to protect and flatten the light-emitting element by forming a resin film made of a resin composition containing resin (A) on the cured film and the light-emitting element, and curing it to form a cured film.

[0430] Thereafter, as shown in Fig. 33h, the opposing substrate 5 is bonded to the cured film 29 using an adhesive or the like. The support substrate 20 is then peeled off, and a barrier metal 9 and bumps 10 are formed, which are electrically connected via the solder bumps 10 to the light-emitting element drive substrate 7 to which drive elements 8 such as driver ICs are attached.

[0431] 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.

[0432] This allows the cured film to ensure electrical insulation of the metal wiring, and extending the metal wiring through the cured film electrically connects a pair of electrode terminals of the light-emitting element to the driving element, thereby controlling the light-emitting operation. Furthermore, the cured film has high light transmittance, which can suppress absorption of light emitted from the light-emitting element and improve light extraction.

[0433] The metal wiring 4 may be replaced with a conductive film 34. Figure 52 shows a process in which a conductive film 34 is used instead of the metal wiring 4.

[0434] The method for producing a display device according to the second aspect of the present invention preferably includes, after the step (E3) and before the step (E4), a step (E8) of exposing the entire region of the resin layer to light.

[0435] By exposing the resin layer after development, the amount of organic acid remaining after heat treatment can be reduced and the breakdown voltage can be improved, so it is preferable to perform the exposure treatment before curing the resin composition containing component (B).When a photoacid generator is used as component (B), it is particularly preferable to expose the resin layer after development.

[0436] In the method for producing a display device according to the second aspect of the present invention, it is preferable to have, 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.

[0437] An example of step (E9) is shown in Figure 34. Figure 34f shows step (E9) of providing partition walls 16 after forming multiple layers of the cured film 3 shown in Figure 33e. Thereafter, light-emitting elements 2 are provided between the partition walls 16 as shown in Figure 34g. Next, as shown in Figure 34h, an opposing substrate 5 is attached to the upper part of the partition walls 16 and the light-emitting elements 2, and the support substrate 20 is peeled off. A barrier metal 9 and bumps 10 are formed, and the light-emitting elements are electrically connected via the solder bumps 10 to a light-emitting element drive substrate 7 having drive elements 8 such as a driver IC.

[0438] The method for producing a display device according to the second aspect of the present invention preferably includes a step (E10) of providing a reflective film on a part of the cured film before the step (E6) and after the step (E5).

[0439] An example of step (E10) is shown in Figure 35. Figure 35f shows step (E10) of providing a reflective film 15 after forming multiple layers of the cured film 3 shown in Figure 33e. The subsequent steps are carried out in the order of the steps shown in Figure 33f, Figure 33g, and Figure 33h, with the reflective film 15 remaining in place.

[0440] The manufacturing method of the display device of the second aspect of the present invention preferably further comprises, after the step (E7), a step (E11) 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 part of the metal wiring extends to the side of the substrate.

[0441] An example of step (E11) is shown in Figure 33. Figure 33h 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 33h, 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.

[0442] 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.

[0443] 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.

[0444] In the method for manufacturing a display device according to the second aspect of the present invention, the metal wiring may be a conductive film (E12).

[0445] An example of the step (E12) is shown in Fig. 45. In Fig. 45h, the driving element is connected to the light emitting element 2 through the metal wiring 4 and the conductive film 34, and part of the conductive film 34 extends to the side surface of the light emitting element driving substrate 7.

[0446] 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.

[0447] The conductive film 34 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.

[0448] Furthermore, a manufacturing method of a display device according to a second aspect of the present invention is a manufacturing method of a display device having at least wiring, a cured film, and a plurality of light-emitting elements, and may include the steps of: (F1) forming a resin film made of a resin composition containing an (A) resin on a substrate or the like; (F2) exposing and developing the resin film to form a pattern of a plurality of penetrating openings in the resin film; (F3) curing the resin film to form the cured film having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less; (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.

[0449] FIG. 46 shows cross-sectional views of the manufacturing process of another embodiment of the display device of the present invention.

[0450] 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 Figure 46a. 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.

[0451] The substrate can be a light emitting element driving substrate 7. Figure 46a shows an example of a TFT array substrate in which TFTs 30, an insulating film 31, and metal wiring 4 are arranged on a glass substrate.

[0452] 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.

[0453] Next, in the step (F2), as shown in FIG. 46a, a pattern of a plurality of penetrating openings is formed in the resin film using a photolithography process.

[0454] Next, as shown in FIG. 46a, the step (F3) is a step of forming a cured film 3 having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less by curing the resin film.

[0455] Next, in step (F4), as shown in Figure 46b, 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 32 is formed on a portion of the surface of the cured film 3 by, for example, a sputtering method. Thereafter, unnecessary photoresist is removed.

[0456] 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.

[0457] 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.

[0458] 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. 46c.

[0459] Next, in step (F5), as shown in Fig. 46d, the light-emitting element 2 is disposed on the cured film 3 so as to maintain electrical connection with the wiring 32. The electrode terminal 6 of the light-emitting element 2 and the wiring 32 may be connected directly or via, for example, a solder ball.

[0460] The partition wall 16 may be formed before or after the light emitting element 2 is disposed.

[0461] Thereafter, as shown in Fig. 46e, an opposing substrate 5 is attached using an adhesive or the like. A conductive film 34 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 34 via the metal wiring 4 and wiring 32 extending into the cured film 3, thereby obtaining a display device 1 having a plurality of light-emitting elements 2. The wiring 32 also includes electrodes.

[0462] This ensures electrical insulation of the wiring through the cured film, and by extending the wiring through the cured film, it is possible to electrically connect a pair of electrode terminals of the light-emitting element to the driving element, thereby controlling light-emitting operation. Furthermore, since the dielectric breakdown voltage of the cured film 3 is 360 kV / mm or more and 600 kV / mm or less, deterioration and electrical leakage of the metal wiring are suppressed, and the defect rate can be reduced even after a reliability test, which is an accelerated test for actual use.

[0463] In the first and second aspects of the present invention, the display device is suitably used in display devices such as various LED displays, various vehicle lamps, and the like. [Example]

[0464] 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.

[0465] <Method for evaluating step flattening rate P (%) of cured film in display device according to first embodiment of the present invention> The step flatness of the cured film was evaluated using the display devices described in the examples and comparative examples in Tables 2-1, 2-2, and 2-3 below. The display devices were processed to prepare cross-sectional samples using a cross-sectional sample preparation device IB-09010CP manufactured by JEOL Ltd. The cross-sectional samples were then measured using a scanning electron microscope S-4800 manufactured by Hitachi High-Tech Corporation to determine the line spacing H1 between two adjacent metal wirings (K2) at the aforementioned region (G), the thickness H2 of the metal wirings (K2), the thickness H3 of the cured film (F1), and the depth H4 of the step in the cured film (F1) formed at region (G), and the step flattening rate P (%) was calculated.

[0466] <Method for evaluating the dielectric breakdown voltage of a cured film according to the second aspect of the present invention> A varnish made from the resin composition was applied to an 8-inch silicon wafer by spin coating using an ACT-8 coater / developer and prebaked at 120°C for 3 minutes to a film thickness of 5 μm. The wafer was then heated at a rate of 3.5°C / min in an inert oven CLH-21CD-S (manufactured by Koyo Thermo Systems Co., Ltd.) at an oxygen concentration of 20 ppm or less, and then subjected to a heat treatment for 1 hour at the curing temperature listed in Tables 4-1 and 4-2. When the temperature reached 50°C or less, the wafer was removed and slowly cooled. The resin composition film was then immersed in 45% by mass hydrofluoric acid for 5 minutes to remove it from the wafer. The dielectric breakdown voltage of the film was measured using a TOS9201 (Kikusui Electronics Co., Ltd.). Ten measurements were performed per sample. The average of the obtained dielectric breakdown voltage values ​​was divided by the thickness (in mm) of the cured film, giving the dielectric breakdown voltage (in kV / mm). The thickness of the prebaked and cured films was measured using an optical interference film thickness measuring device Lambda Ace STM-602 manufactured by Dainippon Screen Mfg. Co., Ltd., with a refractive index of 1.629, and the thickness of the cured film was measured with a refractive index of 1.629.

[0467] <Method for Evaluating Defect Rate After Reliability Test in the Second Aspect of the Present Invention> Ten display devices each having three light-emitting elements described in the examples and comparative examples in Tables 4-1 and 4-2 below were prepared, and a reliability test was performed on these display devices using a HAST device (HAST CHAMBER EHS-211MD, manufactured by Tabai Spec Co., Ltd.) at a temperature of 85°C, humidity of 85%, and a voltage of 5V for 2000 hours, followed by a visual lighting inspection. The percentage of light-emitting elements that did not light up was evaluated as the defect rate for the ten display devices.

[0468] <Evaluation of opening pattern shape of cured film made of resin composition according to the first and second aspects of the present invention> 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.

[0469] 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.

[0470] 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.

[0471] <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.

[0472] 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:

[0473] [ka]

[0474] <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).

[0475] <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).

[0476] <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).

[0477] <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 Co., Ltd.), 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 together 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 (manufactured by Mitsubishi Rayon Co., Ltd.) 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).

[0478] <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.

[0479] <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.

[0480] <Synthesis Example 8: Synthesis of Polyimide Precursor (A-7)> 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.

[0481] Next, under ice cooling, a solution of 206.3 g (1.00 mol) of dicyclohexylcarbodiimide (DCC) dissolved in 180 g of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring. Subsequently, a suspension of 90.2 g (0.45 mol) of 4,4'-DAE suspended in 350 g of γ-butyrolactone was added over 60 minutes with stirring. After further stirring at room temperature for 2 hours, 30 ml of ethyl alcohol was added and 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.

[0482] 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-7).

[0483] <Synthesis Example 9: Synthesis of Polyimide Precursor (A-8)> 155.1 g (0.50 mol) of ODPA was placed in a 2-L separable flask, and 134.0 g (1.00 mol) of 2-hydroxyethyl methacrylate (HEMA) and 400 g of γ-butyrolactone were added. 79.1 g of pyridine was added with stirring at room temperature to obtain a reaction mixture. After the heat generated by the reaction had subsided, the mixture was allowed to cool to room temperature and then allowed to stand for a further 16 hours.

[0484] 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.

[0485] 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-8).

[0486] <Synthesis Example 10: 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 at room temperature. 12.7 g of triethylamine mixed with 50 g of γ-butyrolactone was added dropwise to the solution, ensuring 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 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.

[0487] [ka]

[0488] <Synthesis Example 11: Synthesis of Photosensitizer (Quinone Diazide Compound) (B-2)> Under a dry nitrogen stream, 21.2 g (0.05 mol) of TrisP-PA (Honshu Chemical Industry Co., Ltd.) and 26.8 g (0.10 mol) of 4-naphthoquinone diazide sulfonic acid chloride (NAC-5, Toyo Gosei Co., Ltd.) were dissolved in 450 g of γ-butyrolactone at room temperature. To this solution, 12.7 g of triethylamine mixed with 50 g of γ-butyrolactone was added dropwise so 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:

[0489] [ka]

[0490] <Synthesis Example 12: Synthesis of Polystyrene Resin (A-10)> 20 g of styrene was added to a mixed solution containing 500 ml of tetrahydrofuran and 0.01 mol of sec-butyllithium as an initiator, and the mixture was polymerized with stirring for 3 hours. The polymerization was terminated by adding 0.1 mol of methanol to the reaction solution. The reaction mixture was then poured into methanol to purify the polymer, and the precipitated polymer was dried, yielding a white polymer. The polymer was then dissolved in 400 ml of acetone, added with a small amount of concentrated hydrochloric acid at 60°C, and stirred for 7 hours. The polymer was then poured into water to precipitate, which was then washed and dried to yield purified polystyrene resin (A-10).

[0491] <Synthesis Example 13: Synthesis of Polyimide Precursor (A-11)> 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 (Mitsubishi Rayon Co., Ltd.) 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-11).

[0492] <Synthesis Example 14: Synthesis of acrylic resin (A-12)> 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 another 24 hours to obtain acrylic 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-12) was 103 mgKOH / g.

[0493] <Synthesis Example 15: Synthesis of acrylic resin (A-13)> 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-13) with a weight-average molecular weight of 15,000 and an acid value of 110 mgKOH / g.

[0494] <Preparation Example 1: Preparation of Photosensitive Conductive Paste 1> A 100 mL clean bottle was charged with 10.0 g of acrylic resin (A-12) as a resin, 0.50 g of "IRGACURE (registered trademark)" OXE-01 (manufactured by Ciba Japan Co., Ltd.) as a photopolymerization initiator, 5.0 g of DMEA as a solvent, and 2.0 g of "Light Acrylate (registered trademark)" BP-4EA (manufactured by Kyoeisha Chemical Co., Ltd.) as a compound having an unsaturated double bond, and mixed using a rotation-revolution vacuum mixer "Awatori Rentaro ARE-310" (manufactured by Thinky Corporation) to obtain 17.5 g of a resin solution (solid content 71.4% by mass).

[0495] 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.

[0496] <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 (mass ratio) of 80 / 20.

[0497] <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 mass% solution of resin (A-13), 50.1 g of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional monomer, 7.5 g of "Irgacure (registered trademark)" 907 (manufactured by BASF) as a photopolymerization initiator and 3.8 g of "KAYACURE (registered trademark)" DETX-S (manufactured by Nippon Kayaku Co., Ltd.), 12.0 g of KBM5103 (manufactured by Shin-Etsu Chemical Co., Ltd.) as an adhesion improver, 3 g of a PGMEA 10 mass% 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 mass%, and a colorant / resin (weight ratio) = 30 / 70.

[0498] <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.

[0499] 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.

[0500] <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.

[0501] The components (A-9), (B-3), (C-1), (C-2), other components, and solvents used in the examples and comparative examples are shown below. (A-9) Phenolic resin MEHC-7851 (manufactured by Meiwa Kasei Co., Ltd.), (C-1) HMOM-TPHAP (Honshu Chemical Industry Co., Ltd.) (C-2) YX4000H (Mitsubishi Chemical Corporation)

[0502] [ka]

[0503] Component (B-3): Photopolymerization initiator NCI-831 (manufactured by ADEKA Corporation) Other ingredients: (F-1): Dipentaerythritol hexaacrylate (DPHA, manufactured by Kyoeisha Chemical Co., Ltd.) solvent: GBL: gamma butyrolactone EL: Ethyl lactate PGME: propylene glycol monomethyl ether.

[0504] In a first embodiment of the present invention, Table 1 shows the formulation of a resin composition comprising (A) a resin, (B) a photosensitizer, and (C) a thermal crosslinker. In Table 1, resin compositions 1-11 and 13-14 were prepared using the solvents listed in Table 1 to have a solids concentration of 40% by mass. Resin composition 12 was prepared using the solvents listed in Table 1 to have a solids concentration of 20% by mass. Tables 2-1, 2-2, and 2-3 show the resin compositions used in the examples, the line-to-line spacing H1 (μm) between two adjacent metal wirings (K2) in region (G), the thickness H2 (μm) of the metal wirings (K2), the thickness H3 (μm) of the cured film (F1), the depth H4 (μm) of the step in the cured film (F1) formed in region (G), the step planarization rate P (%), the total thickness (μm) of the cured film, the number of layers of the cured film, the shape and length of the opening pattern machined into the cured film, and the angle of the inclined sides of the opening pattern. Shows.

[0505] [Table 1]

[0506] [Table 2-1]

[0507] [Table 2-2]

[0508] [Table 2-3]

[0509] Regarding the evaluation level (1), the display device was classified as Level A when the step flattening rate P of the display device was 90% or more and the longest length of the opening pattern was 5 μm or less, Level B when the step flattening rate P of the display device was 80% to 89% and the longest length of the opening pattern was 5 μm or less, Level C when the step flattening rate P of the display device was 70% to 79% and the longest length of the opening pattern was 5 μm or less, Level D when the step flattening rate P of the display device was 70% or more and the longest length of the opening pattern was more than 5 μm and 10 μm or less, Level E when the step flattening rate P of the display device was 70% or more and the longest length of the opening pattern was greater than 10 μm, and Level F when the step flattening rate P of the display device was less than 70%.

[0510] 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°.

[0511] (Example 1) (Configuration of FIG. 14) 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. 14a, a glass substrate was used as the support substrate 20. A temporary bonding material made of polyimide was placed on the glass substrate, and LED2, a light-emitting element, was placed on the support substrate 20. LED2 had a thickness of 7 μm, one side length of 30 μm, and the other side length of 50 μm.

[0512] Next, as shown in FIG. 14b, resin composition 1 shown in Table 1 was spin-coated on the support substrate 20 and the light emitting element 2 so that the thickness after heat treatment would be 10 μm, thereby forming a resin film 21.

[0513] Next, as shown in Fig. 14c, the resin film 21 was irradiated with i-line (365 nm) through a mask having a desired pattern. The exposed resin film 21 was developed using a 2.38 mass % tetramethylammonium (TMAH) aqueous solution to form a plurality of opening patterns 12 penetrating the resin film 21 in the thickness direction. 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.

[0514] Next, the resin film 21 was heat-treated at 110°C for 30 minutes in an atmosphere with an oxygen concentration of 100 ppm or less, and then further heat-treated at 230°C for 60 minutes to be cured, thereby forming a 10 μm-thick cured film 3. The resin film 21 was cured as it was and became the cured film 3.

[0515] Next, as shown in Figure 14d, 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 a copper metal wiring (K1) 4a electrically connected to the LED 2 was formed in the opening pattern 12 of the cured film 3 by plating, and a metal wiring (K2) 4b was formed on part of the surface of the cured film 3. The photoresist, seed layer, and barrier metal were then removed. The thickness H2 of the metal wiring (K2) 4b was 5 μm.

[0516] Thereafter, as shown in Figures 14e-f, two layers of cured film 3a were formed, each having metal wiring (K1) 4a and metal wiring (K2) 4b in the cured film 3a. The thickness H2 of the metal wiring (K2) 4b was 5 μm, and the thickness H3 of the cured film (F1) 3a was 10 μm. In addition, a region (G) 28 where the line spacing H1 between two adjacent metal wirings (K2) 4b was 20 μm was formed on a part of the surface of the cured film 3 near the LED 2. As a result, the total thickness of the three-layer cured film 3 was 30 μm.

[0517] Thereafter, in Fig. 14g, a barrier metal 9 was formed by sputtering in the opening pattern 12 of the cured film 3a, to form solder bumps 10. Thereafter, as shown in Fig. 14h, the solder was reflowed at 250°C for 1 minute, and the substrate was 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 20 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.

[0518] Examples 2 to 11 Display devices 2 to 11 were obtained in the same manner as in Example 1, except that resin composition 1 in Example 1 was changed to resin compositions 2 to 11.

[0519] Example 12 A display device 12 was obtained in the same manner as in Example 1, except that the resin composition 1 in Example 1 was changed to the resin composition 12 and the resin film 21 was formed by slit coating.

[0520] Example 13 A display device 13 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 21 was formed by lamination.

[0521] Example 14 In Example 14, a display device 14 was obtained in the same manner as in Example 2, except that in Example 2, a portion (G) was formed in which the line spacing H1 was 2 μm, the thickness H2 of the metal wiring (K2) was 1.5 μm, the thickness H3 of the cured film (F1) 3 a was 3 μm, and the total thickness of the three-layer cured film 3 was 9 μm.

[0522] Example 15 Example 15 was carried out in the same manner as Example 2, except that a portion (G) where the line spacing H1 was 5 μm was formed in Example 2, to obtain a display device 15.

[0523] (Examples 16 to 17) In Examples 16 and 17, display devices 16 and 17 were obtained in the same manner as in Example 2, except that, of the multiple-layered cured film 3a in Example 2, the thickness H3 of the cured film (F1) 3a closest to the LED 2 was set to 7 μm and 20 μm, and the total thickness of the three-layered cured film 3 was 27 μm and 40 μm.

[0524] Example 18 In Example 18, a display device 18 was obtained in the same manner as in Example 4, except that in Example 4, a portion (G) was formed in which the line spacing H1 was 2 μm, the thickness H2 of the metal wiring (K2) was 2 μm, the thickness H3 of the cured film (F1) 3 a was 4 μm, and the total thickness of the three-layer cured film 3 was 12 μm.

[0525] Example 19 Example 19 was carried out in the same manner as in Example 4, except that a portion (G) where the line spacing H1 was 5 μm was formed, to obtain a display device 19.

[0526] Example 20 In Example 20, a display device 20 was obtained in the same manner as in Example 4, except that, of the multiple-layered cured films 3a in Example 4, the thickness H3 of the cured film (F1) 3a closest to the LED 2 was formed to be 7 μm, and the total thickness of the three-layered cured film 3 was 27 μm.

[0527] Examples 21 to 22 In Examples 21 and 22, the same method as in Example 4 was used to obtain display devices 21 and 22, except that in Example 4, portions were formed in which the thickness H2 of the metal wiring (K2) was 5 μm or 10 μm, and among the multiple layers of cured film 3a, the thickness H3 of the cured film (F1) 3a closest to the LED 2 was formed to be 15 μm, and the total thickness of the three-layer cured film 3 was 35 μm.

[0528] Example 23 As shown in Figure 15a, partition walls 16 were formed on a support substrate 20. Next, as shown in Figure 15b, LEDs 2 were formed between the partition walls 16. Then, a display device 23 was manufactured using the same steps as in Example 4, except that a resin film 21 was provided as shown in Figure 15c. The LEDs 2 had a thickness of 7 µm, and the partition walls 16 were formed to a thickness of 10 µm. The partition walls 16 were made of an acrylic resin containing a known white pigment.

[0529] Example 24 As shown in Fig. 16d, after the process of forming the cured film shown in Fig. 14c in the same manner as in Example 4, aluminum was formed to a thickness of 0.2 µm by sputtering at a predetermined position so as to avoid the metal wiring (K2) 4b that would be formed later, to provide a reflective film 15. Except for this, a display device 24 was manufactured using the same process as in Example 4.

[0530] Example 25 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. 17a, a metal wiring (K2) 4b made of copper was disposed on a support substrate 20. The thickness H2 of the metal wiring (K2) 4b was 5 µm. Next, as shown in FIG. 17b, resin composition 1 shown in Table 1 was spin-coated onto the support substrate 20 and the metal wiring (K2) 4b so as to have a thickness of 10 μm after heat treatment, thereby forming a resin film 21. Next, as shown in FIG. 17c, a plurality of opening patterns 12 were formed in the resin film 21 under the same conditions as in the photolithography process shown in Example 1.

[0531] Next, the resin film 21 was cured under the same conditions as in Example 1 to form a cured film 3a having a thickness of 10 μm.

[0532] Subsequently, in FIG. 17c, a barrier metal such as titanium was sputtered onto the cured film 3a, and a copper seed (seed layer) was further formed thereon by sputtering.

[0533] Next, as shown in FIG. 17d, a photoresist layer was formed, and then a metal wiring (K1) 4a made of copper was formed in the opening pattern 12 of the cured film 3a by plating, and a metal wiring (K2) 4b was formed on a portion of the surface of the cured film 3a. The photoresist, seed layer, and barrier metal were then removed. The thickness H2 of the metal wiring (K2) 4b was 5 μm. The photoresist, seed layer, and barrier metal were then removed.

[0534] Then, as shown in Figure 17e, three layers of cured film 3a were formed, each having metal wiring (K1) 4a and metal wiring (K2) 4b in the cured film 3a. The thickness H2 of the metal wiring (K2) 4b was 5 μm, and the thickness H3 of the cured film (F1) 3a was 10 μm. A region (G) 28, where the line spacing H1 between two adjacent metal wirings (K2) 4b was 20 μm, was formed on a portion of the surface of the cured film 3a near the LED 2. As a result, the total thickness of the three-layer cured film 3 was 30 μm.

[0535] Next, as shown in Fig. 17f, the LED 2 was placed on the cured film 3a so as to maintain electrical connection with the metal wiring (K1) 4a and the metal wiring (K2) 4b. The thickness of the LED 2 was 7 µm. Next, as shown in Fig. 17g, a resin film 21 made of the resin composition 1 was formed on the cured film 3a and the light-emitting element 2, and cured by heat treatment to form a cured film 29. The cured film 29 was formed by heat treatment at 110°C for 30 minutes in an atmosphere with an oxygen concentration of 100 ppm or less, followed by further heat treatment at 230°C for 60 minutes. Next, as shown in Figure 17h, the support substrate 20 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 25 having multiple LEDs 2.

[0536] (Examples 26 to 27) Display devices 26 to 27 were obtained in the same manner as in Example 25, except that resin composition 1 in Example 26 was changed to resin compositions 2 and 4.

[0537] Example 28 A display device 28 was obtained in the same manner as in Example 25, except that the resin composition 1 in Example 25 was changed to the resin composition 12 and the resin film 21 was formed by slit coating.

[0538] Example 29 As shown in Figure 18f, multiple layers of the cured film 3a shown in Figure 17e were formed in the same manner as in Example 26, and then partition walls 16 were formed using resin composition 2 between and around the LEDs 2 to be placed later. Then, multiple LEDs 2 were arranged as shown in Figure 18g. As shown in Figure 18h, the support substrate 20 was peeled off, and a light-emitting element drive substrate 7 having a driver IC (driver element 8) was electrically connected via solder bumps 10. Furthermore, an opposing substrate 5 was attached to the LEDs 2 using an adhesive or the like, thereby obtaining a display device 29 having multiple LEDs 2. The LEDs 2 were 7 μm thick, and the partition walls were 10 μm thick.

[0539] Example 30 19f, after the process of forming the cured film 3a and the process of forming the metal wiring (K1) 4a and the metal wiring (K2) 4b in the same manner as in Example 27, aluminum was formed to a thickness of 0.5 μm by sputtering at a predetermined position so as to avoid the formed metal wiring (K2) 4b, to provide a reflective film 15. Thereafter, a display device 30 was manufactured in the same manner as in Example 27.

[0540] Example 31 A display device 31 was manufactured in the same manner as in Example 27, except that NLD-L-672 (manufactured by Sanyu Rec Co., Ltd.) was used as the cured film 29 formed on the light-emitting element 2 and the cured film 29 was formed by heat treatment at 150°C for 360 minutes.

[0541] Example 32 In Example 4, as shown in Fig. 14h, 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 that order by sputtering, and then copper was formed by plating to form the metal wiring 22. Other than that, the same method as in Example 1 was carried out to obtain a display device 38.

[0542] Example 33 17h, 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 that order by sputtering, and then copper was formed by plating to form the metal wiring 22. Except for this, the same method as in Example 27 was carried out to obtain a display device 39.

[0543] Example 34 On the side surface of the light-emitting element driving substrate 7 of Example 32, a conductive film 34 was used as shown in FIG. 43h, and the photosensitive conductive paste 1 of Preparation Example 1 was used as the conductive film 34. The rest of the process was the same as in Example 32, and a display device 40 was obtained. The conductive film 34 was produced as follows.

[0544] <Preparation of Conductive Film 34> 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.

[0545] Example 35 On the side surface of the light-emitting element driving substrate 7 of Example 33, a conductive film 34 was used as shown in Figure 45h, and the photosensitive conductive paste 1 described in Example 34 was used as the conductive film 34. Otherwise, the same method as in Example 33 was carried out to obtain a display device 41.

[0546] Example 36 A display device 42 was obtained in the same manner as in Example 32, except that a printed wiring board was used as the light-emitting element driving substrate 7 of Example 32 and the driving elements 8 and metal wiring 4 were connected via wiring and bumps in the printed wiring board.

[0547] Example 37 A display device 43 was obtained in the same manner as in Example 33, except that a printed wiring board was used as the light-emitting element driving substrate 7 of Example 33 and the driving elements 8 and metal wiring 4 were connected via wiring and bumps in the printed wiring board.

[0548] Example 38 As shown in Fig. 44a, a light-shielding layer 35 made of a colored resin composition 1 was formed on a support substrate 20. Next, as shown in Fig. 44a, an LED 2 was formed between the light-shielding layers 35. Except for this, a display device 44 was manufactured using the same steps as in Example 4. The light-shielding layer 35 was manufactured as follows.

[0549] <Preparation of Light-Shielding Layer 35> The colored resin composition 1 was applied to a support substrate 20 so as to have a thickness of 1 μm after heat treatment, and the applied film was heated and dried for 2 minutes on a hot plate at 100° C. The 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.

[0550] Example 39 A display device 45 was produced in the same manner as in Example 38, except that the light-shielding layer 35 in Example 38 was changed to the colored resin composition 2 to form the light-shielding layer 35 .

[0551] Example 40 In FIG. 14f, a display device 46 was obtained in the same process as in Example 4, 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.

[0552] Example 41 In FIG. 17b, a display device 47 was obtained in the same process as in Example 27, 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.

[0553] Example 42 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. 46a, a TFT array substrate was used as the light-emitting element driving substrate 7, and the resin composition 3 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 21. The thickness of the metal wiring 4 was 1 μm. Next, a plurality of opening patterns 12 were formed in the resin film 21 under the same conditions as in the photolithography process shown in Example 4.

[0554] Next, the resin film 21 was cured under the same conditions as in Example 4 to form a cured film 3 having a thickness of 3 μm.

[0555] Next, as shown in Figure 46b, 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 25 on a portion of the surface of the cured film 3 by sputtering. Thereafter, unnecessary photoresist was removed. The thickness of the ITO was 0.1 µm.

[0556] Next, as shown in FIG. 46c, the above steps were repeated to cure resin composition 3 shown in Table 1, thereby forming a cured film 3 having a thickness of 2 μm.

[0557] Next, as shown in Fig. 46d, partition walls 16 were formed on the cured film 3. Next, LEDs 2 were formed between the partition walls 16. The thickness of the LEDs 2 was 7 µm, and the thickness of the partition walls 16 was 8 µm. The partition walls 16 were made of a known acrylic resin containing a white pigment.

[0558] Thereafter, as shown in Fig. 46e, an opposing substrate 5 was attached using an adhesive. In addition, a conductive film 27 was formed using the photosensitive conductive paste 1 of Preparation Example 1 as the conductive film 34, and a driving element 8 such as a driver IC was electrically connected to the light-emitting element 2 via the metal wiring 4 and wiring 32 extending into the cured film 3 through the conductive film 34, thereby obtaining a display device 48 having a plurality of LEDs 2.

[0559] As a result, the display devices 1 to 31 and 38 to 48 had a high step flattening rate of the cured film 3a, which suppressed the steps caused by stacking the cured film, metal wiring, and light-emitting elements. This prevented wiring defects such as wiring shorts and connection defects of the light-emitting elements, thereby reducing the rate of light-emitting defects when used as a display device. Furthermore, compared to conventional flexible substrates, the cured film was thinner, which enabled the reduction of wiring defects such as wiring shorts due to the reduction of package height and wiring distance, reduced loss, and improved high-speed response. Furthermore, the display devices 1 to 9, 11 to 31, and 38 to 48 were capable of microfabrication, allowing for the use of tiny 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 16, and forming the partition wall facilitated the bonding of the opposing substrate. Furthermore, in display devices 1-31, 38-41, and 44-48, 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 44 and 45 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 46 and 47, 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.

[0560] (Comparative Examples 1 and 2) Display devices 32 and 33 were obtained in the same manner as in Example 1, except that resin composition 1 in Example 1 was changed to resin compositions 13 and 14, and development was carried out with cyclopentanone.

[0561] (Comparative Example 3) Comparative Example 3 was carried out in the same manner as Comparative Example 1, except that a region (G) was formed in which the line spacing H1 between two adjacent metal wirings (K2) was 2 μm, the thickness H2 of the metal wirings (K2) was 2 μm, the thickness H3 of the cured film (F1) 3a was 4 μm, and the total thickness of the three-layer cured film 3 was 12 μm, to obtain a display device 34.

[0562] Comparative Example 4 Comparative Example 4 was carried out in the same manner as Comparative Example 1, except that a region (G) was formed in which the line-to-line spacing H1 between two adjacent metal wirings (K2) was 5 μm, to obtain a display device 35.

[0563] (Comparative Examples 5 to 6) In Comparative Examples 5 and 6, the display devices 36 and 37 were obtained in the same manner as in Comparative Example 1, except that, of the multiple-layered cured film 3a in Comparative Example 1, the thickness H3 of the cured film (F1) 3a closest to the LED 2 was set to 7 μm and 20 μm, and the total thickness of the three-layered cured film 3 was 27 μm and 40 μm. As a result, in the display devices 32 to 37, since the step flattening rate of the cured film 3a was low, the steps caused by stacking the cured film, metal wiring, and light-emitting elements were not eliminated, resulting in wiring defects such as short circuits and poor connection of the light-emitting elements, and poor light emission was observed when the device was used as a display device.

[0564] In a second aspect of the present invention, Table 3 shows the formulation of a resin composition comprising (A) a resin, (B) a photosensitizer, and (C) a thermal crosslinker. In Table 3, resin compositions 101-115 were prepared using the solvents shown in Table 3 to have a solids concentration of 40% by mass. Tables 4-1 and 4-2 show the resin compositions used in the examples, the breakdown voltage (kV / mm) of the cured film of the resin composition, the overall thickness (μm) of the cured film, the number of layers of the cured film, the shape and longest length of the opening pattern processed in the cured film, whether or not step (D6) or step (D8) was performed, the defect rate of the display device, and the angle of the inclined side of the opening pattern.

[0565] [Table 3]

[0566] [Table 4-1]

[0567] [Table 4-2]

[0568] Regarding the evaluation level (1), the display device with a defect rate of 0.25 or less and a maximum length of the opening pattern of 5 μm or less was classified as Level A, the display device with a defect rate of more than 0.25 but not more than 0.35 and a maximum length of the opening pattern of 5 μm or less was classified as Level B, the display device with a defect rate of 0.35 or less and a maximum length of the opening pattern of 5 μm or less was classified as Level C, the display device with a defect rate of 0.35 or less and a maximum length of the opening pattern of 20 μm or more and 25 μm or less was classified as Level D, the display device with a defect rate of more than 0.35 but not more than 0.45 was classified as Level E, and the display device with a defect rate of more than 0.45 was classified as Level F. Levels A to E are levels that present no problems in practical use, and Level F is a level where the display device has a high defect rate and is problematic in practical use.

[0569] 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°.

[0570] (Example 101) (Configuration of Figure 30) 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. As shown in Fig. 30a, a glass substrate was used as the support substrate 20. A temporary bonding material made of polyimide was placed on the glass substrate, and LED2, a light-emitting element, was placed on the support substrate 20 (corresponding to step (D1)). LED2 had a thickness of 7 µm, one side length of 30 µm, and the other side length of 50 µm.

[0571] Next, as shown in FIG. 30b, resin composition 101 described in Table 3 was applied onto supporting substrate 20 and light-emitting element 2 so as to have a thickness of 10 μm after heat treatment, thereby forming resin film 21 (corresponding to step (D2)).

[0572] Next, as shown in Figure 30c, i-line (365 nm) light was irradiated onto the resin film 21 through a mask having a desired pattern. The exposed resin film 21 was developed using a 2.38 mass % aqueous solution of tetramethylammonium (TMAH), forming a plurality of opening patterns 12 penetrating the resin film 21 in the thickness direction (corresponding to step (D3)). The opening patterns were circular, and the longest length of the bottom surface of the smallest region of the opening pattern was 2 µm in diameter.

[0573] Next, the resin film 21 was heat-treated at 110°C for 30 minutes in an atmosphere with an oxygen concentration of 100 ppm or less, and then further heat-treated at 230°C for 60 minutes to be cured, thereby forming a cured film 3 with a thickness of 10 μm (corresponding to step (D4)). The resin film 21 was cured as it was and became the cured film 3.

[0574] Next, as shown in FIG. 30d, 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, and 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.

[0575] 30e-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.

[0576] Thereafter, in Fig. 30g, a barrier metal 9 was formed by sputtering in the opening pattern 12 of the cured film 3, to form solder bumps 10. Thereafter, as shown in Fig. 30h, the solder was reflowed at 250°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 20 was peeled off, and the opposing substrate 5 was attached using an adhesive or the like, thereby obtaining a display device 101 having a plurality of LEDs 2.

[0577] Example 102 A display device 102 was obtained in the same manner as in Example 101, except that the resin composition 101 in Example 101 was changed to a resin sheet made of resin composition 102, and the resin film 21 was formed by lamination.

[0578] (Examples 103 to 111) Display devices 103 to 111 were obtained in the same manner as in Example 1, except that the resin composition 101 in Example 101 was changed to resin compositions 103 to 111.

[0579] Example 112 A display device 112 was obtained in the same manner as in Example 101, except that the resin composition 101 in Example 101 was changed to a resin composition 112, a photoresist was formed before exposure, and the photoresist was removed after development.

[0580] Example 113 Example 113 was carried out in the same manner as Example 2, except that in Example 102, a step (D6) was added after step (D3) and before step (D4), in which i-line (365 nm) was irradiated onto the entire area of ​​the resin film 21 on which the opening pattern 12 obtained in step (D3) was patterned, and a display device 113 was obtained.

[0581] Example 114 As shown in FIG. 31a, partition walls 16 were formed on a support substrate 20 (corresponding to step D7). Next, as shown in FIG. 31b, LEDs 2 were formed between the partition walls 16 (corresponding to step (D1)). Except for this, a display device 114 was manufactured using the same steps as in Example 103. The LEDs 2 had a thickness of 7 μm, and the partition walls 16 were formed to a thickness of 10 μm. The partition walls 16 were made of an acrylic resin containing a known white pigment.

[0582] Example 115 As shown in Fig. 32d, after the step (D4) of forming the cured film shown in Fig. 30c in the same manner as in Example 103, aluminum was formed to a thickness of 0.2 µm by sputtering at a predetermined position so as to avoid the metal wiring 4 that would be formed later, to provide a reflective film 15 (step (D8)). Except for this, a display device 115 was manufactured using the same steps as in Example 103.

[0583] Example 116 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.

[0584] First, as shown in Fig. 33a, an electrode pad 18 made of copper was placed on a support substrate 20 (corresponding to step (E1)). The thickness of the electrode pad was 0.2 µm. Next, as shown in FIG. 33b, resin composition 101 described in Table 3 was applied onto support substrate 20 and metal pad 18 so as to have a thickness of 10 μm after heat treatment, thereby forming resin film 21 (corresponding to step (E2)).

[0585] Next, as shown in FIG. 33c, a plurality of opening patterns 12 were formed in the resin film 21 under the same conditions as in the photolithography step shown in Example 1 (corresponding to step (E3)).

[0586] Next, the resin film 21 was cured under the same conditions as in Example 101 to form a cured film 3 having a thickness of 10 μm (corresponding to step (E4)).

[0587] Next, in FIG. 33c, 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.

[0588] Next, as shown in FIG. 33d, 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.

[0589] Thereafter, steps (E2), (E3), (E4) and (E5) were repeated twice to form three layers of cured films 3 each having metal wiring 4 therein, as shown in Figure 33e. As a result, the total thickness of the three layers of cured films 3 was 30 µm.

[0590] Next, as shown in Fig. 33f, 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.

[0591] Next, as shown in Fig. 33g, a resin film 21 made of the resin composition 101 was formed on the cured film 3 and the light-emitting element 2, and cured by heat treatment to form a cured film 29. 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.

[0592] Next, as shown in Figure 33h, the support substrate 20 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 LEDs 2 using an adhesive or the like, thereby obtaining a display device 116 having multiple LEDs 2.

[0593] (Examples 117 to 118) Display devices 117 to 118 were obtained in the same manner as in Example 116, except that resin composition 101 in Example 116 was changed to resin compositions 102 to 103.

[0594] Example 119 In Example 117, a display device 119 was obtained in the same manner as in Example 117, except that after step (E3) and before step (E4), a step (E8) was added in which i-line (365 nm) was irradiated onto the entire area of ​​the resin film 21 on which the opening pattern 12 obtained in step (E3) was patterned.

[0595] Example 120 As shown in Figure 34f, multiple layers of the cured film 3 shown in Figure 33e were formed in the same manner as in Example 118, and then partition walls 16 were formed between and around the LEDs 2 to be placed later using resin composition 103 (corresponding to step (E9)). Thereafter, multiple LEDs 2 were arranged as shown in Figure 34g. As shown in Figure 34h, the support substrate 20 was peeled off, and a light-emitting element drive substrate 7 having a driver IC, which is a drive element 8, was electrically connected via solder bumps 10. In addition, an opposing substrate 5 was attached to the LEDs 2 using an adhesive or the like, thereby obtaining a display device 120 having multiple LEDs 2. The LEDs 2 had a thickness of 7 μm, and the partition walls had a thickness of 10 μm.

[0596] Example 121 As shown in Figure 35f, after the step (E5) of forming the cured film shown in Figure 33e in the same manner as in Example 118, aluminum was formed to a thickness of 0.5 µm by sputtering at a predetermined position so as to avoid the formed metal wiring 4, and a reflective film 15 was provided (step (E10)). Thereafter, a display device 121 was manufactured in the same steps as in Example 118.

[0597] Example 122 A display device 122 was obtained in the same manner as in Example 101, except that the resin composition 101 in Example 101 was changed to the resin composition 113.

[0598] Example 123 A display device 123 was obtained in the same manner as in Example 101, except that the resin composition 101 in Example 101 was changed to the resin composition 114 and the exposed resin film 21 was developed using cyclopentanone.

[0599] Example 124 In Example 103, as shown in Fig. 30h, 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 (step (D9)). Except for this, the same method as in Example 101 was carried out to obtain a display device 126.

[0600] Example 125 In Example 118, as shown in Fig. 33h, 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 (step (E11)). Except for this, the same method as in Example 118 was carried out to obtain a display device 127.

[0601] Example 126 On the side surface of the light-emitting element driving substrate 7 of Example 124, a conductive film 34 was used as shown in FIG. 43h, and the photosensitive conductive paste 1 of Preparation Example 1 was used as the conductive film 34 (step (D10)). Except for this, the same method as in Example 124 was carried out to obtain a display device 128. The conductive film 34 was produced as follows.

[0602] <Preparation of Conductive Film 34> 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. 2After 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.

[0603] Example 127 On the side surface of the light-emitting element driving substrate 7 of Example 125, a conductive film 34 was used as shown in Fig. 45h, and the photosensitive conductive paste 1 described in Example 126 was used as the conductive film 34 (step (E12)). Otherwise, the same method as in Example 125 was carried out, and a display device 129 was obtained.

[0604] Example 128 A display device 130 was obtained in the same manner as in Example 124, except that a printed wiring board was used as the light-emitting element driving substrate 7 in Example 124 and the driving elements 8 and metal wiring 4 were connected via wiring and bumps in the printed wiring board.

[0605] Example 129 A display device 131 was obtained in the same manner as in Example 125, except that a printed wiring board was used as the light-emitting element driving substrate 7 in Example 125 and the driving elements 8 and metal wiring 4 were connected via wiring and bumps in the printed wiring board.

[0606] Example 130 As shown in Fig. 44a, a light-shielding layer 35 made of a colored resin composition 1 was formed on a support substrate 20 (step (D11)). Next, as shown in Fig. 44a, an LED 2 was formed between the light-shielding layers 35 (step (D1)). Except for this, a display device 132 was manufactured using the same steps as in Example 103. The light-shielding layer 35 was manufactured as follows.

[0607] <Preparation of Light-Shielding Layer 35> The colored resin composition 1 was applied to a support substrate 20 so as to have a thickness of 1 μm after heat treatment, and the applied film was heated and dried for 2 minutes on a hot plate at 100° C. The 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.

[0608] Example 131 A display device 133 was produced in the same manner as in Example 130, except that the light-shielding layer 35 in Example 130 was changed to the colored resin composition 2 to form the light-shielding layer 35 .

[0609] Example 132 In FIG. 30f, a display device 134 was obtained in the same process as in Example 103, 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.

[0610] Example 133 In FIG. 33b, a display device 135 was obtained in the same manner as in Example 118, 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.

[0611] Example 134 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. 46a, a TFT array substrate was used as the light-emitting element driving substrate 7, and the resin composition 103 described in Table 3 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 21 (step (F1)). The thickness of the metal wiring 4 was 1 μm. Next, a plurality of opening patterns 12 were formed in the resin film 21 under the same conditions as in the photolithography step shown in Example 103 (step (F2)).

[0612] Next, the resin film 21 was cured under the same conditions as in Example 103 to form a cured film 3 having a thickness of 3 μm (step (F3)).

[0613] Next, as shown in Figure 46b, 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 25 on a portion of the surface of the cured film 3 by a sputtering method. Thereafter, unnecessary photoresist was removed (step (F4)). The thickness of the ITO was 0.1 µm.

[0614] Next, as shown in FIG. 46c, steps (F1), (F2) and (F3) were repeated to cure the resin composition 103 shown in Table 3, thereby forming a cured film 3 having a thickness of 2 μm.

[0615] Next, as shown in Fig. 46d, partition walls 16 were formed on the cured film 3. Next, LEDs 2 were formed between the partition walls 16 (step (F5)). The thickness of the LEDs 2 was 7 µm, and the thickness of the partition walls 16 was 8 µm. The partition walls 16 were made of a known acrylic resin containing a white pigment.

[0616] Thereafter, as shown in Fig. 46e, an opposing substrate 5 was attached using an adhesive. In addition, a conductive film 34 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 metal wiring 4 and wiring 32 extending into the cured film 3 through the conductive film 34, thereby obtaining a display device 136 having a plurality of LEDs 2.

[0617] As a result, the display devices 101 to 123 and 126 to 136 had a low failure rate after reliability testing due to the high breakdown voltage of the cured film 3. Furthermore, the cured film was thinner than conventional flexible substrates, which enabled the suppression of wiring defects such as wiring shorts due to a low package height and short wiring distances, reduced loss, and improved high-speed response. Furthermore, the display devices 101 to 110, 113 to 121, and 124 to 134 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 16, and the formation of the partition wall facilitated the bonding of the opposing substrate. Furthermore, in the display devices 101 to 123, 126 to 129, and 132 to 136, at least a portion of the metal wiring or conductive film extended to the side surface of the substrate, thereby enabling the display device itself to be low-profile and high-speed response, and further enabling the display device to be made smaller and have a narrower frame. Furthermore, by forming a light-shielding layer between multiple light-emitting elements in display devices 132 and 133, it was possible to suppress light leakage from the light-emitting elements and color mixing between pixels and improve contrast without significantly impairing light extraction efficiency. In display devices 134 and 135, the thickness of the metal wiring near bumps 10 was thicker than the thickness of the metal wiring near LEDs 2, which made it possible to suppress wiring defects when connecting light-emitting element drive substrate 7 using bumps 10, and it was possible to obtain display devices with high reliability.

[0618] (Comparative Example 101) A display device 124 was obtained in the same manner as in Example 101, except that the resin composition 101 in Example 101 was changed to the resin composition 113 and the curing temperature was changed to the temperature shown in Table 4-1.

[0619] (Comparative Example 102) A display device 125 was obtained in the same manner as in Example 101, except that the resin composition 101 in Example 101 was changed to the resin composition 115. As a result, the defective rate was high in display device 124 because the dielectric breakdown voltage of cured film 3 was less than 360 kV / mm, and in display device 125 because the dielectric breakdown voltage of cured film 3 exceeded 600 kV / mm. [Explanation of symbols]

[0620] 1 Display device 2 Light-emitting element 3 Cured film 3a Hardened film (F1) in contact with a part of the surface of the metal wiring (K2) 103a: Thickness of the cured film 103a covering the metal wiring 104a 4, 4c, 22 metal wiring 4a Metal wiring (K1) extending in the thickness direction of the cured film (F1) 4b Metal wiring (K2) connected to the metal wiring (K1) and extending in a planar direction perpendicular to the thickness direction of the cured film (F1) 104a Thickness of metal wiring arranged on the surface of the cured film 104b 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, 111b Specified area B 11c, 111c Specified area C 12 Opening Pattern 13 Bottom surface of metal wiring 4 14 Maximum length of bottom surface 15 Reflective film 16 Bulkhead 17 External board 19 Total thickness of the cured film 20 Support substrate 21 Resin film 23 Line spacing H1 between two adjacent metal wirings (K2) 24 Thickness H2 of metal wiring (K2) 25 Thickness of cured film (F1) H3 26 Step depth H4 27 areas (M1) 28 parts (G) 29 Cured film 30 TFT 31 TFT insulating layer 32 Wiring 33 Contact Hole 34 Conductive film 34a Conductive film (K101) extending in the thickness direction of the cured film (F1) 34b A conductive film (K102) connected to the conductive film (K101) and extending in a planar direction perpendicular to the thickness direction of the cured film (F1) 35 Light blocking layer 36 Inclined Edge 37 Angle of Inclined Side 38 Thickness of cured film 3 39 Position at 1 / 2 thickness of cured 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 one surface thereof, the pair of electrode terminals are connected to the plurality of metal wirings extending in the cured film; the plurality of metal wirings are configured to maintain electrical insulation by the cured film; The metal wiring includes a plurality of metal wirings (K1) extending in a thickness direction of the cured film, and a plurality of metal wirings (K2) connected to the metal wirings (K1) and extending in a planar direction perpendicular to the thickness direction of the cured film, the cured film is a film obtained by curing a resin composition containing (A) resin, a cured film in contact with a part of the surface of the metal wiring (K2), The display device has at least a region (G) in which the line spacing H1 between two adjacent metal wirings (K2) is 1 to 20 μm, In the region (G), the thickness of the metal wiring (K2) is H2 (μm), the thickness of the cured film is H3 (μm), and the depth of the step of the cured film generated in the region (G) is H4 (μm). H3 / H2 is 1.4 to 4.0, A display device in which the step flattening rate P (%) represented by (Equation 1) is 70 to 99%. P (%)=(1-(H4 / H2))×100...(Formula 1)

2. 2. The display device according to claim 1, wherein the thickness H2 of the metal wiring (K2) is 1.5 to 10 μm.

3. 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 one surface, 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, and the cured film is a film obtained by curing a resin composition containing (A) resin, and the dielectric breakdown voltage of the cured film is 360 kV / mm or more and 600 kV / mm or less.

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

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

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. The display device according to any one of claims 1 to 7, wherein the cured film further comprises a reflective film.

9. 9. 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.

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

11. 11. 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.

12. 12. 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 a metal wiring, and at least a part of the metal wiring extending to a side surface of the substrate.

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

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

15. 15. The display device according to claim 1, wherein the resin (A) further contains a phenol resin having a biphenyl structure.

16. 16. The display device according to claim 1, wherein the resin composition containing the resin (A) further contains a photosensitizer (B).

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

18. The display device according to claim 17 , wherein the thermal crosslinking agent (C) contains a thermal crosslinking agent having a biphenyl structure.

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

20. 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; (D2) a step of forming a resin film made of a resin composition containing a resin (A) on the supporting substrate and the light-emitting element; 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 (D4) of curing the resin film to form a cured film having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less; 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.

21. 21. The method for manufacturing a display device according to claim 20, further comprising the step (D6) of exposing the entire region of the resin film to light after the step (D3) and before the step (D4).

22. 22. The method for manufacturing a display device according to claim 20, further comprising the step of repeating the steps (D2), (D3), (D4), and (D5) 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 20, further comprising, after the step (D1), a step (D7) of providing a partition wall having a thickness equal to or greater than the thickness of the light-emitting elements between the plurality of light-emitting elements.

24. The method for manufacturing a display device according to any one of claims 20 to 23, further comprising the step (D8) of providing a reflective film on a part of the cured film after the step (D4).

25. 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; (E2) a step of forming a resin film made of a resin composition containing (A) a resin on the support substrate and the metal pads; 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 (E4) of curing the resin film to form the cured film having a breakdown voltage of 360 kV / mm or more and 600 kV / mm or less; 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.

26. 26. The method for manufacturing a display device according to claim 25, further comprising the step (E8) of exposing the entire region of the resin layer to light after the step (E3) and before the step (E4).

27. 27. The method for manufacturing a display device according to claim 25, further comprising the step of repeating the steps (E2), (E3), (E4), and (E5) multiple times to form multiple layers of the cured film having the metal wiring therein.

28. The method for manufacturing a display device according to any one of claims 25 to 27, 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.

29. The method for manufacturing a display device according to any one of claims 25 to 28, further comprising a step (E10) of providing a reflective film on a part of the cured film after the step (E5) and before the step (E6).

Images