Wavelength conversion substrate and display device

Abstract

Provided is a technique that, in a display device provided with a wavelength conversion substrate provided with partition walls, does not readily cause a decrease in brightness and a loss in color due to the generation of bubbles in a wavelength conversion layer. A wavelength conversion substrate (3) is provided with: a transparent substrate (31) having a first main surface; a resin layer (34) provided on the first main surface and having a plurality of through-hole groups each including a first through-hole, a third through-hole, and a second through-hole located therebetween; an inorganic coating layer (35) that at least partially covers the side walls of the first to third through-holes, respectively; and wavelength conversion layers (36R, 36G) in at least a part of the through-holes, the taper angle of each of the side wall of the first through-hole on the second through-hole side, the side walls of the second through-hole on the first through-hole side and the third through-hole side, and the side wall of the third through-hole on the second through-hole side being 3-40 degrees, and the opening of each of the first through-holes to the third through-hole on the transparent substrate (31) side being 3-40 degrees. The ratio (W1 / L1) of the dimension (W1) in the direction in which the first to third through-holes are arranged to the dimension (L1) in the direction perpendicular to the direction is 0.01-0.95, and the dimension (L1) is 10-1000 [mu] m.

Description

Technical Field

[0001] The present invention relates to a wavelength conversion substrate and a display device. Background Art

[0002] In a display device, a light-emitting element such as a light-emitting diode is used, for example, as a light source of a backlight unit, or as a component of a pixel or a sub-pixel. In such a display device, a partition wall is sometimes provided to separate the light-emitting element, or the pixel or the sub-pixel from each other. The partition wall can, for example, effectively utilize the light emitted by the light-emitting element, or prevent the light emitted by other light-emitting elements from entering the area where the light emitted by a certain light-emitting element should enter.

[0003] Patent Documents 1 and 2 propose a display device including a wavelength conversion layer including a color conversion phosphor that converts the wavelength of blue light into red light and green light. Such a display device can display a color image even with a monochromatic light source.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2000-131683

[0007] Patent Document 2: Japanese Patent Application Publication No. 2009-244383 Summary of the invention

[0008] Two or more wavelength conversion layers that convert light from a light source into light of different colors can be formed in two or more recesses separated from each other by a partition wall. If a partition wall is provided, for example, a thicker wavelength conversion layer can be formed with higher positional accuracy. Therefore, a higher wavelength conversion efficiency can be achieved, and color mixing can be less likely to occur.

[0009] As a method for forming a wavelength conversion layer in the above-mentioned concave portion, there are a method of using a photosensitive material as a coating liquid and drawing a coating film by photolithography, and a nozzle coating method of selectively supplying the coating liquid to a specific position. In either method, bubbles are easily generated between the inner surface of the concave portion and the coating film, and in the coating film. The bubbles generated in the wavelength conversion layer may cause problems such as reduced brightness and color loss in the display device.

[0010] An object of the present invention is to provide a technology that makes it difficult for a display device including a wavelength conversion substrate provided with partition walls to suffer from a decrease in brightness and a loss in color due to the generation of bubbles in a wavelength conversion layer.

[0011] According to one aspect of the present invention, there is provided a wavelength conversion substrate, comprising: a transparent substrate having a first main surface and a second main surface; a resin layer, disposed on the first main surface, having a plurality of through hole groups, each including a first through hole, a third through hole, and a second through hole located therebetween; an inorganic cover layer, comprising a plurality of first portions, each at least partially covering the side walls of the first to third through holes; and a wavelength conversion layer, comprising a plurality of wavelength conversion portions, each disposed in at least a portion of the first to third through holes, wherein the taper angle θ of the side wall of the first through hole on the second through hole side is 12 , the taper angle θ of the side wall of the second through hole on the first through hole side 21 , the taper angle θ of the side wall of the second through hole on the third through hole side 22 , and a taper angle θ of a side wall of the third through hole on the second through hole side 31 , respectively in the range of 3 to 40 degrees, the openings of the first to third through holes on the transparent substrate side are respectively such that the ratio W1 / L1 of the dimension W1 in the first direction in which the first to third through holes are arranged to the dimension L1 in the second direction perpendicular to the first direction is in the range of 0.01 to 0.95, and the dimension L1 is in the range of 10 to 1000 μm.

[0012] According to another aspect of the present invention, there is provided a wavelength conversion substrate as described above, wherein the taper angle θ of the side wall of the first through hole on the side opposite to the second through hole side is 11 , and a taper angle θ of the side wall of the third through hole on the side opposite to the second through hole side 32 , respectively in the range of 0 to 40 degrees.

[0013] According to another aspect of the present invention, there is provided a wavelength conversion substrate as described above, wherein the taper angle θ of the side wall of the first through hole on the side opposite to the second through hole side is 11 , and a taper angle θ of the side wall of the third through hole on the side opposite to the second through hole side 32 , respectively in the range of 3 to 40 degrees.

[0014] According to another aspect of the present invention, there is provided a wavelength conversion substrate as described in any one of the above aspects, wherein the cone angle θ 11 and θ 32 are respectively smaller than the cone angle θ 12 ,θ 21 ,θ 22 and θ 31 Any one of.

[0015] According to another aspect of the present invention, there is provided a wavelength conversion substrate as described in any one of the above aspects, wherein the cone angle θ 11 and θ 32 is 0 degrees.

[0016] According to further aspects of the present invention, a wavelength conversion substrate according to any one of the above aspects is provided, wherein the side wall of the first through hole on the opposite side to the second through hole and the side wall of the third through hole on the opposite side to the second through hole are respectively substantially vertical.

[0017] According to further aspects of the present invention, a wavelength conversion substrate as described in any one of the above aspects is provided, wherein the inorganic covering layer also includes a plurality of second parts, which extend at the positions of the openings of the first to third through holes on the transparent substrate side and respectively have fourth through holes whose sizes are smaller than the openings.

[0018] According to further aspects of the present invention, a wavelength conversion substrate as described in the above aspects is provided, wherein the ratio W1 / L1 is in the range of 0.01 to 0.75, and the ratio L2 / L1 of the size L2 of the fourth through hole in the second direction to the size L1 is in the range of 0.01 to 0.80.

[0019] According to further aspects of the present invention, there is provided a wavelength conversion substrate as described in any one of the above aspects, wherein the inorganic covering layer further includes a third portion that at least partially covers the upper surface of the resin layer and is adjacent to the first portion.

[0020] According to still another aspect of the present invention, there is provided a wavelength conversion substrate as described in any one of the above aspects, wherein the depth of each of the first to third through holes is in the range of 10 to 40 μm.

[0021] According to still another aspect of the present invention, there is provided a wavelength conversion substrate as described in any one of the above aspects, wherein the inorganic covering layer is composed of a metal or an alloy.

[0022] According to further aspects of the present invention, there is provided a wavelength conversion substrate as described in any one of the above aspects, further comprising a black matrix, which is sandwiched between the transparent substrate and the resin layer and has a plurality of fifth through holes at the positions of the first to third through holes, respectively.

[0023] According to further aspects of the present invention, a wavelength conversion substrate as described in the above aspects is provided, wherein the ratio W1 / L1 is in the range of 0.01 to 0.75, and the ratio L3 / L1 of the size L3 of the fifth through hole in the second direction to the size L1 is in the range of 0.01 to 0.80.

[0024] According to still another aspect of the present invention, there is provided the wavelength conversion substrate according to any one of the above aspects, further comprising a color filter including a plurality of colored layers respectively arranged at positions of at least a portion of the plurality of fifth through holes.

[0025] According to still another aspect of the present invention, there is provided a display device comprising: the wavelength conversion substrate according to any one of the above aspects; and a dimming device provided to face the first main surface.

[0026] According to still another aspect of the present invention, there is provided a display device as described in the above aspect, wherein the dimming device comprises: a substrate; and a plurality of light emitting diodes arranged on the substrate corresponding to the first to third through holes.

[0027] According to the present invention, there is provided a technique for preventing a decrease in brightness and a loss in color due to the generation of bubbles in a wavelength conversion layer from occurring easily in a display device including a wavelength conversion substrate provided with partition walls. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a plan view showing a part of the display device according to the embodiment of the present invention.

[0029] Figure 2 yes Figure 1 The equivalent circuit diagram of the display device shown.

[0030] Figure 3 It is along Figure 1 A cross-sectional view of the display device taken along line III-III is shown.

[0031] Figure 4 It is along Figure 1 A cross-sectional view of the display device taken along line IV-IV is shown.

[0032] Figure 5 Yes means Figure 1 A top view of a portion of a wavelength conversion substrate included in a display device.

[0033] Figure 6 It is a shorthand representation of Figure 5 A top view of the structure of a wavelength conversion substrate with some of its components omitted.

[0034] Figure 7 This is a schematic diagram showing bubbles generated in the coating film when coating is applied to the surface of the structure before the wavelength conversion layer is formed in Example 1.

[0035] Figure 8This is a schematic diagram showing bubbles generated in the coating film when coating is applied to the surface of the structure before the wavelength conversion layer is formed in Example 2.

[0036] Fig. 9 This is a schematic diagram showing bubbles generated in the coating film when coating is applied to the surface of the structure before the wavelength conversion layer is formed in Example 3.

[0037] Fig.10 This is a schematic diagram showing bubbles generated in the coating film when coating is applied to the surface of the structure before the wavelength conversion layer is formed in Example 4.

[0038] Fig.11 This is a schematic diagram showing bubbles generated in the coating film when coating is applied to the surface of the structure before the wavelength conversion layer is formed in Comparative Example 1.

[0039] Fig.12 This is a schematic diagram showing bubbles generated in the coating film when coating is performed on the surface of a structure before forming a wavelength conversion layer in Comparative Example 2.

[0040] Fig.13 This is a schematic diagram showing bubbles generated in the coating film when coating is applied to the surface of the structure before the wavelength conversion layer is formed in Comparative Example 3.

[0041] Fig.14 This is a schematic diagram showing bubbles generated in the coating film when coating is performed on the surface of a structure before forming a wavelength conversion layer in Comparative Example 4. DETAILED DESCRIPTION

[0042] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are obtained by further specifying any one of the above aspects. The matters described below can be incorporated into each of the above aspects individually or in combination of a plurality.

[0043] In addition, the embodiments shown below are examples of structures for embodying the technical concept of the present invention, and the technical concept of the present invention is not limited by the material, shape and structure of the following components. Various changes can be made to the technical concept of the present invention within the technical scope specified by the claims described in the claims.

[0044] In addition, for elements having the same or similar functions, the same reference numerals are given in the following referenced figures, and repeated descriptions are omitted. In addition, the drawings are schematic, and the relationship between the dimensions in a certain direction and the dimensions in other directions and the relationship between the dimensions of a certain component and the dimensions of other components may be different from the actual.

[0045] Figure 1 It is a plan view showing a part of the display device according to the embodiment of the present invention. Figure 2 yes Figure 1 The equivalent circuit diagram of the display device shown. Figure 3 It is along Figure 1 A cross-sectional view of the display device taken along line III-III is shown. Figure 4 It is along Figure 1 A cross-sectional view of the display device taken along line IV-IV is shown. Figure 5 express Figure 1 A display device includes a top view of a portion of a wavelength conversion substrate. Figure 1 In FIG. 1 , the region surrounded by the dotted line indicates the opening of the third through hole of the black matrix 32 on the transparent substrate 31 side as described later.

[0046] Figures 1 to 4 The display device 1 shown is capable of color display using an active matrix drive method and is a micro LED display in which each sub-pixel includes a light emitting diode (LED).

[0047] In each figure, the X direction and the Y direction are directions parallel to the display surface of the display device 1 and intersecting each other. According to one example, the X direction and the Y direction are perpendicular to each other. In addition, the Z direction is a direction perpendicular to the X direction and the Y direction. That is, the Z direction is the thickness direction of the display device 1.

[0048] like Figure 2 As shown, the display device 1 includes a video signal line VSL, a power line PSL, a scanning signal line SSL, a pixel PX, a video signal line driver VDR and a scanning signal line driver SDR.

[0049] The video signal lines VSL and the power supply lines PSL extend in the Y direction and are alternately arranged in the X direction. The scanning signal lines SSL extend in the X direction and are alternately arranged in the Y direction.

[0050] The pixels PX are arranged along the X direction and the Y direction. Each pixel PX includes a first sub-pixel PXR, a second sub-pixel PXG, and a third sub-pixel PXB. The first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB are arranged corresponding to the intersection of the video signal line VSL and the scanning signal line SSL.

[0051] The first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB emit light of different colors. Here, as an example, the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB emit red light, green light, and blue light, respectively.

[0052] In each pixel PX, the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB are sequentially arranged in the X direction. The arrangement order of the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB in each pixel PX can be changed.

[0053] In addition, the first sub-pixel PXR, the second sub-pixel PXG and the third sub-pixel PXB form a stripe arrangement. The first sub-pixel PXR, the second sub-pixel PXG and the third sub-pixel PXB may also form other arrangements such as a delta arrangement and a mosaic arrangement.

[0054] The first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB include a light emitting element D, a driving control element DR, a switch SW, and a capacitor C, respectively.

[0055] The light-emitting element D is a light-emitting diode. The light-emitting diode is, for example, a light-emitting diode made of an inorganic substance. The light-emitting diode made of an inorganic substance is obtained, for example, by monolithicizing a laminate having the same layer structure as them into a plurality of parts. The light-emitting element D may also be an electroluminescent element as a light-emitting diode made of an organic substance. The cathode of the light-emitting element D is connected to the ground electrode. Here, as an example, it is assumed that the light-emitting element D is made of an inorganic substance and is a blue light-emitting diode that emits blue light.

[0056] The drive control element DR and the switch SW are field effect transistors. Here, the drive control element DR is a p-channel thin film transistor, and the switch SW is an n-channel thin film transistor. The drive control element DR is configured such that the gate is connected to the drain of the switch SW, the source is connected to the power supply line PSL, and the drain is connected to the anode of the light emitting element D. The switch SW is configured such that the gate is connected to the scanning signal line SSL, and the source is connected to the video signal line VSL.

[0057] The capacitor C is, for example, a thin film capacitor and is configured such that one electrode of the capacitor C is connected to the gate of the drive control element DR and the other electrode of the capacitor C is connected to the power supply line PSL.

[0058] The first sub-pixel PXR also includes Figure 3 as well as Figure 4 The first wavelength conversion layer 36R and the first coloring layer 33R are shown.

[0059] The first wavelength conversion layer 36R is provided so as to face the light emitting element D of the first sub-pixel PXR. The first wavelength conversion layer 36R converts the light emitted by the light emitting element D of the first sub-pixel PXR into the first light of a specific color. For example, the first wavelength conversion layer 36R converts the blue light emitted by the light emitting element D of the first sub-pixel PXR into red light.

[0060] The first colored layer 33R is provided so as to face the light emitting element D of the first sub-pixel PXR with the first wavelength conversion layer 36R interposed therebetween. The first colored layer 33R transmits the light after the wavelength conversion by the first wavelength conversion layer 36R, and absorbs the light not subjected to the wavelength conversion by the first wavelength conversion layer 36R. The first colored layer 33R is, for example, a red colored layer that transmits the red light after the wavelength conversion by the first wavelength conversion layer 36R, and absorbs the blue light not subjected to the wavelength conversion by the first wavelength conversion layer 36R.

[0061] The second sub-pixel PXG also includes Figure 3 The second wavelength conversion layer 36G and the second coloring layer 33G are shown.

[0062] The second wavelength conversion layer 36G is provided so as to face the light emitting element D of the second sub-pixel PXG. The second wavelength conversion layer 36G converts the light emitted by the light emitting element D of the second sub-pixel PXG into a second light of a color different from the first light. For example, the second wavelength conversion layer 36G converts the blue light emitted by the light emitting element D of the second sub-pixel PXG into green light.

[0063] The second colored layer 33G is disposed so as to face the light emitting element D of the second sub-pixel PXG with the second wavelength conversion layer 36G interposed therebetween. The second colored layer 33G transmits the light after the wavelength conversion by the second wavelength conversion layer 36G is converted, and absorbs the light not converted by the second wavelength conversion layer 36G is converted. The second colored layer 33G is, for example, a green colored layer that transmits the green light after the wavelength conversion by the second wavelength conversion layer 36G is converted, and absorbs the blue light not converted by the second wavelength conversion layer 36G is converted.

[0064] The third sub-pixel PXB also includes Figure 3 Shown are a base layer 33B and a filler layer 36B.

[0065] The filling layer 36B is provided so as to face the light emitting element D of the third sub-pixel PXB. The filling layer 36B is, for example, a colorless and transparent layer. The filling layer 36B can be omitted.

[0066] The base layer 33B is disposed so as to face the light emitting element D of the third sub-pixel PXB with the filling layer 36B interposed therebetween. The base layer 33B transmits the light emitted by the light emitting element D of the third sub-pixel PXB as the third light. The base layer 33B is, for example, a colorless light-transmitting layer or a blue colored layer that transmits the blue light emitted by the light emitting element D of the third sub-pixel PXB.

[0067] Image signal line driver VDR and scan signal line driver SDR Figure 2As shown, the image signal line driver VDR and the scanning signal line driver SDR may be mounted on the display panel by COG (chip on glass) technology. Instead of COG mounting, the image signal line driver VDR and the scanning signal line driver SDR may be mounted by TCP (tape carrier package).

[0068] The video signal line driver VDR is connected to the video signal line VSL and the power supply line PSL, and outputs a voltage signal as a video signal to the video signal line VSL.

[0069] The scanning signal line driver SDR is connected to the scanning signal line SSL. The scanning signal line driver SDR outputs a voltage signal as a scanning signal to the scanning signal line SSL. The power line PSL may be connected to the scanning signal line driver SDR instead of being connected to the video signal line driver VDR.

[0070] The display device 1 will be described in more detail.

[0071] like Figure 3 as well as Figure 4 As shown, the display device 1 includes a dimming substrate 2 , a wavelength conversion substrate 3 , and an adhesive layer 4 .

[0072] The light-adjusting substrate is a substrate that emits light toward the wavelength conversion substrate and is capable of adjusting at least one of the intensity of the light and the time of emitting the light for each pixel or each sub-pixel. Figure 3 as well as Figure 4 The dimming substrate 2 shown includes a substrate 21 , a semiconductor layer 22 , conductor layers 23A, 23B, 23C and 23D, insulating layers 24A, 24B and 24C, a light emitting element 25 , a partition layer 26 , a filling layer 27 and a conductor layer 28 .

[0073] The substrate 21 includes, for example, an insulating substrate such as a glass substrate. The substrate 21 may also include a primer layer provided on the main surface of the insulating substrate facing the wavelength conversion substrate 3. The primer layer is, for example, a laminate of a silicon nitride layer and a silicon oxide layer sequentially laminated on the insulating substrate. The substrate 21 may also be a semiconductor substrate such as a silicon substrate. The substrate 21 may be either hard or flexible.

[0074] The semiconductor layer 22 is arranged on the main surface of the substrate 21 facing the wavelength conversion substrate 3. The semiconductor layer 22 is, for example, a polysilicon layer. The semiconductor layer 22 is a semiconductor layer constituting a thin film transistor of the drive control element DR or the switch SW. Each semiconductor layer 22 includes a source and a drain and a channel region sandwiched therebetween.

[0075] The conductor layer 23A is a conductor pattern provided on the main surface of the substrate 21. The conductor layer 23A constitutes the video signal line VSL, the power line PSL, the source electrode SE, the drain electrode DE, and the lower electrode (not shown) of the capacitor C. The source electrode SE and the drain electrode DE are connected to the source and the drain of the semiconductor layer 22, respectively. The conductor layer 23A is made of metal or alloy. The conductor layer 23A may have a single-layer structure or a multi-layer structure.

[0076] The insulating layer 24A covers the conductor layer 23A and the main surface of the substrate 21. The insulating layer 24A can be formed using TEOS (tetraethyl orthosilicate), for example. The gate insulating film of each thin film transistor constituting the drive control element DR or the switch SW is a part of the insulating layer 24A. In addition, the dielectric layer of each capacitor C is another part of the insulating layer 24A.

[0077] The conductor layer 23B is a conductor pattern provided on the insulating layer 24A. The gate electrode GE of each thin film transistor constituting the drive control element DR or the switch SW is a part of the conductor layer 23B. Each gate electrode GE faces the channel region of the semiconductor layer 22 with the insulating layer 24A in between. In addition, the upper electrode (not shown) of each capacitor C is another part of the conductor layer 23B. Each upper electrode faces the lower electrode of the capacitor C including the upper electrode with the insulating layer 24A in between. The conductor layer 23B is made of metal or alloy. The conductor layer 23B can have a single-layer structure or a multi-layer structure.

[0078] The insulating layer 24B covers the conductive layer 23B and the insulating layer 24A. The insulating layer 24B is an interlayer insulating film. The insulating layer 24B is made of, for example, an inorganic insulator such as silicon oxide. The insulating layer made of an inorganic insulator can be formed by, for example, a plasma CVD (chemical vapor deposition) method.

[0079] like Figure 4 As shown, the conductor layer 23C is a conductor pattern provided on the insulating layer 24B. The conductor layer 23C constitutes the scanning signal line SSL. The source electrode SE and the drain electrode DE may be provided on the insulating layer 24B instead of being provided on the insulating layer 24A. That is, the scanning signal line SSL and the source electrode SE and the drain electrode DE may also be constituted by the conductor layer 23C.

[0080] The insulating layer 24C covers the conductive layer 23C and the insulating layer 24B. The insulating layer 24C is a passivation film and is made of an inorganic insulator such as silicon nitride.

[0081] The conductor layer 23D is a conductor pattern provided on the insulating layer 24C. The conductor layer 23D constitutes electrode pads arranged in the X direction and the Y direction corresponding to the first sub-pixel PXR, the second sub-pixel PXG, and the third sub-pixel PXB. In the stacked body composed of the insulating layers 24A, 24B, and 24C, a through hole is provided at the position of the drain electrode DE connected to the drain of the drive control element DR. Each electrode pad is connected to the drain electrode DE via the through hole. The conductor layer 23D is composed of, for example, a metal or an alloy. The conductor layer 23D may have a single-layer structure or a multi-layer structure.

[0082] The contour of the orthographic projection of each electrode pad onto a plane perpendicular to the Z direction is separated from the orthographic projection of the light emitting element 25 disposed on the electrode pad onto the above-mentioned plane and surrounds the orthographic projection. That is, the electrode pad is larger in the direction perpendicular to the Z direction than the light emitting element 25. Therefore, the electrode pad also acts as a reflective layer that reflects the light traveling toward the substrate 21. The electrode pad may not play the role of the reflective layer. In this case, the reflective layer that plays this role may be provided separately from the electrode pad or may not be provided.

[0083] Figure 3 as well as Figure 4 The light emitting element 25 shown is Figure 2 The light emitting element D shown. The light emitting element 25 is arranged on the electrode pad.

[0084] Here, the light emitting element 25 is a light emitting diode made of an inorganic substance. In addition, a substrate including a light emitting diode as the light emitting element 25 is sometimes referred to as an "LED substrate".

[0085] The light emitting element 25 has a multilayer structure including a plurality of layers, for example, a first layer 251, a second layer 252, and a third layer 253. Here, the stacking direction of the layers included in the light emitting element 25 is the Z direction. The stacking direction may be perpendicular to the Z direction.

[0086] Each light emitting element 25 includes an anode and a cathode. The light emitting element 25 has an anode and a cathode on one surface. The anode of the light emitting element 25 is connected to the electrode pad via a bonding wire (not shown). In the case where the light emitting element 25 has an anode on one surface and a cathode on the other surface, the light emitting element 25 can be bonded to the electrode pad and the anode can be connected to the electrode pad by bare chip bonding using a conductive material such as a conductive paste as a bonding material. In the case where the light emitting element 25 has an anode and a cathode on one surface, the conductor layer 28 can be omitted, and an electrode pad for connecting to the cathode of the light emitting element 25 can be further provided on the insulating layer 24C, and wiring connected to these electrode pads can be further provided between the insulating layers, and the light emitting element 25 can be bonded to the electrode pad and the conductor layer 28, and the anode and cathode can be connected to the electrode pad by flip chip bonding.

[0087] The dimensions of the light emitting element 25 in the X and Y directions are preferably in the range of 1 to 100 μm, more preferably in the range of 5 to 80 μm, and further preferably in the range of 10 to 60 μm. The dimension of the light emitting element 25 in the Z direction is preferably in the range of 1 to 20 μm, more preferably in the range of 1 to 15 μm, and further preferably in the range of 1 to 10 μm.

[0088] The partition layer 26 is disposed on the insulating layer 24C. The partition layer 26 has through holes at the positions of the electrode pads. The light-emitting elements 25 are respectively located in these through holes. The partition layer 26 is made of, for example, resin. Such a partition layer 26 can be formed by photolithography using a photosensitive resin. The partition layer 26 can also include a resin layer having through holes, and a reflective layer covering the side walls of these through holes and the upper surface of any resin layer. The reflective layer can have a single-layer structure or a multi-layer structure. The layers included in the reflective layer are, for example, metals, alloys, or transparent dielectrics. The partition layer 26 can be omitted.

[0089] The filling layer 27 fills the gap between the light emitting element 25 and the partition layer 26. The filling layer 27 is a light-transmitting layer that transmits the light emitted by the light emitting element 25. In addition, the filling layer 27 also acts as a protective layer for protecting the light emitting element 25 and the joint between the light emitting element 25 and the electrode. The filling layer 27 is composed of, for example, a resin. The refractive index of the filling layer 27 is preferably different from the refractive index of the material constituting the surface of the partition layer 26.

[0090] The conductor layer 28 is provided on the partition layer 26 and the filling layer 27. The cathode of the light emitting element 25 is connected to the conductor layer 28. When the conductor layer 28 is composed of a conductive transparent oxide, it can be provided so as to cover the entire cathode of the light emitting element 25. When the conductor layer 28 is composed of a metal or an alloy, it is preferably provided so as to cover part of the cathode of the light emitting element 25.

[0091] The wavelength conversion substrate 3 faces the light-adjusting substrate 2. Specifically, the wavelength conversion substrate 3 faces the substrate 21 with the light-emitting element 25 and the like interposed therebetween.

[0092] The wavelength conversion substrate 3 includes a transparent substrate 31, a black matrix 32, a resin layer 34, an inorganic cover layer 35, a color filter including a first coloring layer 33R and a second coloring layer 33G, a base layer 33B, a first wavelength conversion layer 36R, a second wavelength conversion layer 36G, and a filling layer 36B.

[0093] The transparent substrate 31 has visible light transmittance. The transparent substrate 31 is, for example, a colorless substrate. The transparent substrate 31 may have a single-layer structure or a multi-layer structure. The transparent substrate 31 is, for example, made of glass, a transparent resin, or a combination thereof. The transparent substrate 31 may be hard or flexible. The transparent substrate 31 has a first main surface facing the dimming substrate 2 and a second main surface as the back surface thereof.

[0094] The black matrix 32 is disposed on the first main surface of the transparent substrate 31. The black matrix 32 is a black layer that blocks visible light. The black matrix 32 is composed of, for example, a mixture containing a binder resin and a colorant. The colorant is, for example, a black pigment, or a mixture of pigments that appear black by subtractive color mixing, such as a mixture containing a blue pigment, a green pigment, and a red pigment.

[0095] The black matrix 32 has fifth through holes at the positions of the light emitting elements 25. The opening of each fifth through hole on the transparent substrate 31 side has a larger dimension in the direction perpendicular to the Z direction than the light emitting element 25.

[0096] Here, the opening of the fifth through hole on the transparent substrate 31 side is as shown in Figure 1 As indicated by the dotted line in the figure, it has a shape extending in the Y direction. The portions corresponding to the pixels PX in the black matrix 32 include a fifth through hole arranged at the position of the first sub-pixel PXR, a fifth through hole arranged at the position of the second sub-pixel PXG, and a fifth through hole arranged at the position of the fifth sub-pixel PXB, and these three fifth through holes are arranged in the X direction. A plurality of fifth through hole groups respectively composed of these three fifth through holes are arranged in the X direction and the Y direction. The distance between the fifth through hole groups adjacent in the X direction is greater than the distance between the fifth through holes included in the same through hole group. The distance between the fifth through hole groups adjacent in the Y direction is also greater than the distance between the fifth through holes included in the same through hole group.

[0097] The aperture ratio of the black matrix 32 is preferably in the range of 5 to 66%, more preferably in the range of 5 to 40%, and further preferably in the range of 5 to 20%. The light-emitting diode composed of inorganic substances can emit light brightly and has a long life even when the light emitting surface is small. Therefore, in the case where the light-emitting element 25 is a light-emitting diode composed of inorganic substances, a bright display can be performed even if the aperture ratio of the black matrix 32 is reduced. In addition, if the aperture ratio of the black matrix 32 is reduced, the reflection of external light can be suppressed, and a darker black can be displayed, thereby achieving a higher contrast.

[0098] The thickness of the black matrix 32 is preferably in the range of 1 to 30 μm, more preferably in the range of 1 to 15 μm, and further preferably in the range of 1 to 5 μm. A thicker black matrix 32 is advantageous in achieving higher light-shielding properties. However, if the black matrix 32 is made thicker, in the pattern exposure performed on the coating film composed of the photosensitive black composition, the light cannot reach the deep part of the coating film with sufficient intensity, and it is possible that a higher shape accuracy cannot be achieved.

[0099] like Figure 3 as well as Figure 4 As shown, the resin layer 34 is provided on the black matrix 32. According to one example, the resin layer 34 is transparent. In this case, the resin layer 34 may be colored or colorless. The resin layer 34 may also have light scattering properties. For example, the transparent resin layer 34 is preferably such that, when the film thickness is assumed to be 5 μm, the maximum value of the transmittance of light within the range of 350 to 480 nm incident in the thickness direction thereof is 20% or more.

[0100] The wavelength conversion substrate 3 may further include an outer coating layer sandwiched between the black matrix 32 and the resin layer 34. The outer coating layer may include one or more of a transparent resin, an ultraviolet absorber, a yellow pigment, and transparent particles. The outer coating layer including the ultraviolet absorber can absorb the stray light incident on the resin layer 34 when it is ultraviolet external light.

[0101] The resin layer 34 has through holes at the positions of the fifth through holes. These through holes constitute a through hole group corresponding to the fifth through hole group. Here, these through hole groups are respectively composed of three first to third through holes arranged in the X direction (hereinafter referred to as "first to third through hole groups".), and the second through hole is located between the first through hole and the third through hole. The first to third through hole groups are arranged in the first direction and the second direction intersecting each other, here, the X direction and the Y direction.

[0102] like Figure 5 As shown, the distance W between the first to third through hole groups adjacent to each other in the X direction is x1 is greater than the distance W between adjacent through holes among the first to third through holes included in the same through hole group. x 2. The distance W between the first to third through hole groups adjacent to each other in the Y direction y 1 is also greater than the distance W between adjacent through holes among the first to third through holes included in the same through hole group. x 2.

[0103] Distance W x 2 is preferably in the range of 5 to 80 μm, more preferably in the range of 5 to 40 μm, further preferably in the range of 5 to 20 μm.

[0104] Distance W x 1 is preferably in the range of 5 to 250 μm, more preferably in the range of 50 to 214.5 μm, further preferably in the range of 100 to 214.5 μm.

[0105] Distance W y 1 is preferably in the range of 5 to 250 μm, more preferably in the range of 5 to 100 μm, further preferably in the range of 5 to 50 μm.

[0106] Distance W x 1 and distance W x 2 ratio W x 1 / W x 2 is preferably in the range of 0.5 to 20, more preferably in the range of 2 to 20, and further preferably in the range of 10 to 20. Distance W x 1 can be related to the distance W x 2 is equal to or smaller than the distance W x 2.

[0107] Distance W y 1 and distance W x 2 ratio W y 1 / W x 2 is preferably in the range of 0.5 to 40, more preferably in the range of 1 to 10, and further preferably in the range of 1.1 to 5. Distance W y 1 can be related to the distance W x 2 is equal to or smaller than the distance W x 2.

[0108] Here, the first to third through holes are arranged so that the contour of the orthographic projection of the opening on the transparent substrate 31 side onto the first main surface (hereinafter referred to as the first contour) respectively surrounds the contour of the orthographic projection of the fifth through hole onto the first main surface (hereinafter referred to as the third contour). The first contour may not surround the third contour. In the structure in which the first contour surrounds the third contour, the influence of stray light on the display is smaller than that in the structure in which the first contour does not surround the third contour.

[0109] In the resin layer 34, the partition wall formed by the portion sandwiched by adjacent through holes included in each of the first to third through hole groups, that is, the partition wall formed by the portion sandwiched by the first through hole and the second through hole, and the partition wall formed by the portion sandwiched by the second through hole and the third through hole, have a positive cone cross-section that satisfies the following requirements.

[0110] That is, in Figure 3 In the resin layer 34 shown in the figure, the through hole filled with the first wavelength conversion layer 36R is set as the first through hole, the through hole filled with the second wavelength conversion layer 36G is set as the second through hole, and the through hole filled with the filling layer 36B is set as the third through hole. At this time, the taper angle θ of the side wall of the first through hole on the second through hole side is 12、 Taper angle θ of the side wall of the second through hole on the first through hole side 21、 Taper angle θ of the side wall of the second through hole on the third through hole side 22、 and the taper angle θ of the side wall of the third through hole on the second through hole side 31 , respectively, are in the range of 3 to 40 degrees. In the case where the taper angle of the above-mentioned side walls of each recessed portion constituting the first to third through holes is within the range, when a coating film is formed in the recessed portion in order to form a wavelength conversion layer, for example, by a die coating method or a nozzle coating method, it is possible to suppress the generation of bubbles between the inner surface of the recessed portion and the coating film, or in the coating film. As a result, it is not easy to produce a reduction in brightness or color loss caused by the generation of bubbles in the wavelength conversion layer. In addition, in the case of forming the fourth through hole possessed by the inorganic covering layer 35 by etching as described later, a coating film is formed in the recessed portion in order to form an etching mask by photolithography. In the case where the taper angle of the above-mentioned side walls constituting the recessed portion is within the range, in the formation of the coating film for the etching mask, it is also possible to suppress the generation of bubbles between the inner surface of the recessed portion and the coating film, or in the coating film, which is effective in suppressing a reduction in brightness or color loss. The taper angle θ of the above-mentioned side walls 12 ,θ 21 ,θ 22 and θ 31 , preferably in the range of 5 to 30 degrees, more preferably in the range of 8 to 25 degrees.

[0111] In the resin layer 34, the partition wall formed by the portion sandwiched between the first to third through hole groups adjacent in the X direction, such as Figure 3 as well as Figure 5 The cross-sectional shape of the partition wall is not limited to the forward tapered shape, and may be, for example, rectangular.

[0112] Figure 3 The taper angle θ of the side wall of the first through hole on the opposite side to the second through hole is shown as 11、and the taper angle θ of the side wall of the third through hole on the side opposite to the second through hole side 32 , are preferably in the range of 0 to 40 degrees, more preferably in the range of 0 to 30 degrees, and further preferably in the range of 0 to 20 degrees. In one embodiment, the taper angle θ 11 and θ 32 It can also be 0 degrees. Here, the cone angle θ 11 and θ 32 0 degrees means that the side wall is vertical, and the partition wall formed by the portion sandwiched between the first to third through-hole groups adjacent to each other in the X direction has a rectangular cross section.

[0113] In one embodiment, the cone angle θ 11 and θ 32 Preferably, the taper angle θ is smaller than the above-mentioned side wall. 12 ,θ 21 ,θ 22 and θ 31 That is, the side wall of the first through hole on the side opposite to the second through hole and the side wall of the third through hole on the side opposite to the second through hole each have a taper angle θ 11 and θ 32 The taper angle θ of the side wall on the second through hole side is preferably smaller than that of the first through hole. 12 , the taper angle θ of the side wall of the second through hole on the first through hole side 21 , the taper angle θ of the side wall of the second through hole on the third through hole side 22 , and the taper angle θ of the side wall of the third through hole on the second through hole side 31 In this case, the heat dissipation of the display device 1 is improved.

[0114] That is, the taper angle θ of the side wall on the second through hole side of the first through hole among the side walls of the concave portions constituting the first to third through holes is 12 , the taper angle θ of the side wall of the second through hole on the first through hole side 21 , the taper angle θ of the side wall of the second through hole on the third through hole side 22 , and the taper angle θ of the side wall of the third through hole on the second through hole side 31 In the above range, it is possible to suppress the generation of bubbles when forming the coating film for the wavelength conversion layer or the coating film for the etching mask, and to exert an excellent effect on suppressing the reduction in brightness and color loss of the display device 1. On the other hand, since the side wall of the first through hole on the side opposite to the second through hole side and the side wall of the third through hole on the side opposite to the second through hole side each have a taper angle θ 11 and θ 32 Smaller than the taper angle θ of the side wall 12 ,θ 21 ,θ22 , and θ 31 Therefore, it can be found that the heat dissipation of the display device 1 is improved. 11 and θ 32 Reducing means that the cross section of the partition wall formed by the portion sandwiched between the first to third through hole groups adjacent in the X direction is made close to a rectangle. In this case, the area of ​​the third portion of the inorganic cover layer 35 covering the upper surface of the resin layer 34 becomes larger. That is, the area of ​​the third portion of the inorganic cover layer 35 close to the light emitting element 25, which is the heat source of the display device 1, becomes larger, so the heat dissipation is improved. In the display device 1, excellent heat dissipation will produce an effect that degradation, brightness reduction and color difference are not easily generated.

[0115] Specifically, the cone angle θ 11 and θ 32 Each with cone angle θ 12 ,θ 21 ,θ 22 and θ 31 The respective differences are preferably in the range of 5 to 30 degrees, more preferably in the range of 10 to 25 degrees, and further preferably in the range of 15 to 20 degrees.

[0116] In another embodiment, when the partition wall has a forward tapered cross section, the taper angle θ is 11 and θ 32 The respective angles are preferably within a range of 3 to 40 degrees, more preferably within a range of 3 to 30 degrees, and still more preferably within a range of 5 to 20 degrees.

[0117] In the resin layer 34, the partition wall formed by the portion sandwiched between the first to third through hole groups adjacent in the Y direction, such as Figure 4 as well as Figure 5 The cross-sectional shape of the partition wall is not limited to the forward tapered shape, and may have a rectangular cross-sectional shape, for example.

[0118] Figure 4 The taper angle θ of the side wall constituting the partition wall in the first through hole filled with the first wavelength conversion layer 36R is shown as follows: 13 and θ 14 The taper angle θ is preferably in the range of 0 to 40 degrees, more preferably in the range of 0 to 30 degrees, and further preferably in the range of 0 to 20 degrees. 13 and θ 14 It can also be 0 degrees. Here, the cone angle θ 13 and θ 14 0 degrees means that the side wall is vertical, and the partition wall formed by the portion sandwiched between the first to third through-hole groups adjacent to each other in the Y direction has a rectangular cross section.

[0119] When the partition wall has a forward tapered cross section, the taper angle θ 13 and θ 14 The respective angles are preferably within a range of 3 to 40 degrees, more preferably within a range of 3 to 30 degrees, and still more preferably within a range of 5 to 20 degrees.

[0120] The taper angles of the side walls constituting the partition walls in the second through hole and the third through hole are also the same.

[0121] The thickness T of the resin layer 34 is preferably in the range of 5 to 50 μm, more preferably in the range of 5 to 40 μm, and further preferably in the range of 10 to 25 μm. When the thickness T of the resin layer 34 is small, it is not easy to increase the total thickness of the layers formed in the first to third through holes. If the resin layer 34 is thickened, the shape accuracy of the partition wall portion sandwiched between adjacent through holes among the first to third through holes is reduced.

[0122] The inorganic cover layer 35 includes a plurality of first portions that at least partially cover the sidewalls of the first to third through holes. Figure 3 as well as Figure 4 As shown, the inorganic cover layer 35 covers the entire side wall of each of the first to third through holes. The inorganic cover layer 35 may not cover a portion of the side wall of the first to third through holes. For example, the inorganic cover layer 35 may not cover at least one of the portion near the black matrix 32 in at least one side wall of the first to third through holes and the portion near the upper surface of the resin layer 34 in at least one side wall of the first through hole.

[0123] The coverage of the first portion of the inorganic cover layer 35 on the side walls of each of the first to third through holes is preferably 60% or more. If the coverage of the side walls by the first portion is 60% or more, when a coating is formed in the recessed portion (the first to third through holes) formed by the partition wall, for example, by die coating or nozzle coating, it is possible to effectively suppress the generation of bubbles between the inner surface of the recessed portion and the coating, and in the coating. The coverage of the side surfaces of the first to third through holes by the first portion of the inorganic cover layer 35 is more preferably 80% or more.

[0124] The inorganic cover layer 35 also includes a plurality of second portions, which extend at the positions of the openings of the first to third through holes on the transparent substrate 31 side and each have a fourth through hole smaller in size than the opening. That is, the inorganic cover layer 35 also includes a second portion covering the black matrix 32 in the first to third through holes. The second portion has a fourth through hole smaller in size than the openings of the first to third through holes on the transparent substrate 31 side. Here, as Figure 4 As shown, the inorganic cover layer 35 has a fourth through hole at the position of the fifth through hole of the black matrix 32. The second portion can be omitted.

[0125] The inorganic covering layer 35 further includes a plurality of third portions that at least partially cover the upper surface of the resin layer 34. Here, the third portion covers the entire upper surface of the resin layer 34. The third portion preferably includes a portion adjacent to the first portion.

[0126] The inorganic cover layer 35 may have a single layer structure or a multilayer structure. The layer included in the inorganic cover layer 35 is, for example, a metal, an alloy or a transparent dielectric. According to one example, the inorganic cover layer 35 is composed of aluminum or an aluminum alloy. The inorganic cover layer 35 is preferably such that the contact angle of the surface relative to the coating liquid is in the range of 1 to 30 degrees, more preferably in the range of 5 to 10 degrees.

[0127] Below, refer to Figure 6 The first to third through holes included in the resin layer 34 , the fourth through hole included in the inorganic cover layer 35 , and the fifth through hole included in the black matrix 32 will be described. Figure 6 It is a shorthand representation of Figure 5 A top view of the structure of the wavelength conversion substrate 3 after omitting part of the components. Specifically, Figure 6 It is a shorthand representation of Figure 5 A top view of the structure after the first wavelength conversion layer 36R, the second wavelength conversion layer 36G and the filling layer 36B are omitted in the wavelength conversion substrate 3. Figure 6 , the length L1 and the width W1 are respectively the dimensions in the X direction and the Y direction of the openings of the first to third through holes of the resin layer 34 on the transparent substrate 31 side. The length L2 and the width W2 are respectively the dimensions in the X direction and the Y direction of the opening of the fourth through hole of the inorganic cover layer 35 on the transparent substrate 31 side. The length L3 and the width W3 are respectively the dimensions in the X direction and the Y direction of the opening of the third through hole of the black matrix 32 on the transparent substrate 31 side.

[0128] The first to third through holes have a length L1 of the opening on the transparent substrate 31 side in the range of 10 to 1000 μm, and a ratio W1 / L1 of the width W1 of the opening to the dimension L1 in the range of 0.01 to 0.95. The openings of the first to third through holes have a shape extending in the Y direction with the dimension, so that bubbles are not easily generated when the coating liquid is filled into the first to third through holes. For the same reason, the depth of the first to third through holes is preferably in the range of 1 to 100 μm, and more preferably in the range of 10 to 40 μm.

[0129] The length L1 of the first to third through holes is preferably in the range of 90 to 600 μm. The ratio W1 / L1 of the width W1 to the length L1 of the first to third through holes is preferably in the range of 0.01 to 0.75. If the above-mentioned coating is performed at a high speed, bubbles may be generated between the inner surface of the recess formed by the partition wall and the coating film or in the coating film. If the length L1 and the ratio W1 / L1 are made within the above-mentioned range, the position of the bubbles generated when the coating is performed at a high speed can be limited to one end of the length direction of the recess. Therefore, the brightness reduction and color loss of the display device caused by bubbles can be suppressed.

[0130] exist Figure 6 In the embodiment, the opening of the fifth through hole is such that the ratio L3 / L1 of the dimension L3 in the length direction (Y direction) of the fifth through hole to the dimension L1 is preferably in the range of 0.01 to 0.80. If the ratio L3 / L1 is in this range, even if bubbles are generated at one end of the recess, the influence of the bubbles on the display can be effectively suppressed. The ratio L3 / L1 is more preferably in the range of 0.15 to 0.50.

[0131] exist Figure 6 In the embodiment, the opening of the fourth through hole is arranged so that the outline of the orthographic projection onto the first main surface (hereinafter referred to as the second outline) respectively surrounds the outline of the orthographic projection of the fifth through hole onto the first main surface (hereinafter referred to as the third outline). The second outline may not surround the third outline. In the case of adopting a structure in which the second outline surrounds the third outline, it is not easy to produce a reduction in contrast due to a position error of the second through hole. In the fourth through hole, the ratio L2 / L1 of the dimension L2 of the fourth through hole in the length direction (Y direction) to the above-mentioned dimension L1 is preferably in the range of 0.01 to 0.80, and more preferably in the range of 0.15 to 0.50.

[0132] like Figure 3 as well as Figure 4 As shown in FIG. 1 , the first colored layer 33R fills the fifth through hole at the position of the first sub-pixel PXR. As described above, here, the first colored layer 33R is a red colored layer.

[0133] like Figure 3 As shown in FIG. 1 , the second colored layer 33G fills the fifth through hole at the position of the second sub-pixel PXG. As described above, here, the second colored layer 33G is a green colored layer.

[0134] like Figure 3 As shown in FIG. 1 , the base layer 33B fills the fifth through hole at the position of the third sub-pixel PXB. As described above, here, the base layer 33B is a colorless light-transmitting layer or a blue colored layer.

[0135] The first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B are filling portions provided in the first to third through holes, respectively.

[0136] The first wavelength conversion layer 36R fills the first through hole at the position of the first sub-pixel PXR. The first wavelength conversion layer 36R is a layer containing a fluorescent material such as a quantum dot fluorescent material and a transparent resin. As described above, here, the first wavelength conversion layer 36R converts the blue light emitted by the light emitting element D of the first sub-pixel PXR into red light.

[0137] The second wavelength conversion layer 36G fills the second through hole at the position of the second sub-pixel PXG. The second wavelength conversion layer 36G is a layer containing a fluorescent material such as a quantum dot fluorescent material and a transparent resin. As described above, here, the second wavelength conversion layer 36G converts the blue light emitted by the light emitting element D of the second sub-pixel PXG into red light.

[0138] The filling layer 36B fills the third through hole at the position of the third sub-pixel PXB. As described above, the filling layer 36B is a colorless and transparent layer. In this case, the filling layer 36B is made of, for example, a transparent resin.

[0139] The adhesive layer 4 is sandwiched between the light-adjusting substrate 2 and the wavelength conversion substrate 3 to bond them to each other. The adhesive layer 4 transmits the light emitted by the light-emitting element 25. The adhesive layer 4 is, for example, a colorless and transparent layer. The adhesive layer 4 is made of an adhesive or a pressure-sensitive adhesive.

[0140] The display device 1 can be manufactured by the following method, for example.

[0141] In manufacturing the display device 1 , first, the wavelength conversion substrate 3 is prepared.

[0142] That is, first, a structure is obtained including a transparent substrate 31 before forming an inorganic covering layer 35, a first wavelength conversion layer 36R, a second wavelength conversion layer 36G and a filling layer 36B for the wavelength conversion substrate 3, a black matrix 32, a color filter including a first coloring layer 33R and a second coloring layer 33G, a base layer 33B, and a resin layer 34.

[0143] The black matrix 32 can be formed by, for example, photolithography using a negative photosensitive black composition. The first coloring layer 33R, the second coloring layer 33G, and the base layer 33B can be formed by, for example, sequentially applying a resin and curing the coating.

[0144] The resin layer 34 can be obtained, for example, by photolithography using a negative photosensitive composition. By appropriately setting exposure conditions and development conditions, a structure having the first to third through holes can be formed. As described above, in the resin layer 34, the side walls of the partition walls formed by the portions sandwiched between the first to third through hole groups adjacent in the X direction, among the side walls of the concave portions forming the first to third through holes, have a taper angle θ of 11 and θ 32 , preferably smaller than the taper angle θ of the side wall of the partition wall formed by the portion sandwiched by the first through hole and the second through hole, and the taper angle θ of the side wall of the partition wall formed by the portion sandwiched by the second through hole and the third through hole 12 ,θ 21 ,θ 22 and θ 31 The resin layer 34 having a plurality of through hole groups each including first to third through holes having side walls with different taper angles can be manufactured by adjusting the exposure amount to have a predetermined taper angle using, for example, a 3D mask or a grayscale mask.

[0145] Next, the inorganic cover layer 35 is formed. Specifically, the material of the inorganic cover layer 35 is deposited by a vapor deposition method such as a sputtering method and a vacuum evaporation method. In this way, the inorganic cover layer 35 including the portion covering the black matrix 32, the first coloring layer 33R, the second coloring layer 33G, and the base layer 33B in addition to the third portion covering the upper surface of the resin layer 34 and the first portion covering the side surfaces of the first to third through holes can be obtained.

[0146] Next, an etching mask is formed. The etching mask is formed so that the portion of the inorganic cover layer 35 where the second through hole is formed is exposed and the other portion is covered by the etching mask. The etching mask can be formed by photolithography using a photosensitive resin. In this case, when the taper angle θ of the side wall of the first through hole is 12 , the taper angle θ of the side wall of the second through hole 21 and θ 22 , and the taper angle θ of the side wall of the third through hole 31 Within the above range, when forming the coating film for etching mask, it is possible to suppress the generation of bubbles between the inner surface of the recessed portion (first to third through holes) of the partition wall and the coating film or in the coating film, thereby making it difficult to cause a decrease in brightness and color loss.

[0147] Next, fourth through holes are formed in the covered portions of the black matrix 32 , the first coloring layer 33R, the second coloring layer 33G, and the base layer 33B by etching using wet etching or the like.

[0148] Next, the etching mask is removed, and then the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B are formed.

[0149] Each of the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B can be formed by, for example, a photolithography method using a negative photosensitive composition.

[0150] Specifically, a negative photosensitive material as a material of the first wavelength conversion layer 36R is applied to the surface of the structure obtained by the above etching, for example, by die coating. In the die coating, for example, the above structure and the slot mold are configured so that the length direction of the slot is parallel to the X direction, and the coating liquid is discharged from the slot mold while moving them relatively in the Y direction. In this way, a coating film is formed on the surface of the above structure. Next, the coating film is pattern-exposed to solidify the photosensitive material that fills the first through hole at the position of the first sub-pixel PXR. Thereafter, the unexposed portion of the coating film is removed by development. Thus, the first wavelength conversion layer 36R is obtained.

[0151] Next, a negative photosensitive material, which is a material of the second wavelength conversion layer 36G, is applied to the surface of the structure after the first wavelength conversion layer 36R is formed, for example, by die coating in the same manner as described above. Next, the coating film is pattern-exposed to cure the photosensitive material that fills the second through hole at the position of the second sub-pixel PXG. Thereafter, the unexposed portion of the coating film is removed by development. Thus, the second wavelength conversion layer 36R is obtained.

[0152] Finally, a negative photosensitive material, which is a material of the filling layer 36B, is applied to the surface of the structure after the first conversion layer 36R and the second conversion layer 36G are formed, for example, by die coating in the same manner as described above. Next, the coating film is pattern-exposed to cure the photosensitive material that fills the third through hole at the position of the third sub-pixel PXB. Thereafter, the unexposed portion of the coating film is removed by development. Thus, the filling layer 36B is obtained.

[0153] Alternatively, the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B can also be formed by a nozzle coating method. In the nozzle coating method, a nozzle head is used that is provided with a plurality of nozzles arranged at a pitch equal to that of the pixel PX in the X direction. Then, while the nozzle head is relatively moved in the Y direction relative to the etched structure obtained by the method described above, the resin composition as the material of the first wavelength conversion layer 36R is discharged from each nozzle into the recess formed by the partition at the position of the first sub-pixel PXR. In this way, the first wavelength conversion layer 36R is obtained by curing the coating formed in the recess. Then, the second wavelength conversion layer 36G and the filling layer 36B are also formed by the same method.

[0154] In addition, the order of forming the first wavelength conversion layer 36R, the second wavelength conversion layer 36G, and the filling layer 36B is arbitrary.

[0155] The wavelength conversion substrate 3 obtained as described above and the light control substrate 2 prepared separately are attached to each other via the adhesive layer 4. Thus, the display device 1 is obtained.

[0156] When the above-described structure is employed for the wavelength conversion substrate 3 of the display device 1 , a decrease in brightness or a loss in color due to the generation of bubbles in the wavelength conversion layer is less likely to occur.

[0157] Example

[0158] Hereinafter, simulations performed in connection with the present invention will be described.

[0159] (Example 1)

[0160] for Figure 1 The wavelength conversion layer formation process in the manufacture of the wavelength conversion substrate 3 included in the display device 1 shown was simulated using the finite volume method analysis software Fluent, and the generation of bubbles in the coating film 50ms after the coating liquid was applied was investigated. Here, the VOF (Volume of Fluid) method was used to calculate the free interface. In addition, the simulation was performed assuming the following conditions. That is, the first to third through holes of the resin layer 34 are such that the length L1 of the opening on the transparent substrate 31 side is 112.5μm, the width W1 is 89.5μm, and the depth is 30μm. In addition, the distance W between adjacent through holes in the first to third through holes is x 2 is 20 μm. Furthermore, the taper angles θ of the sidewalls of the first through hole on the second through hole side, the sidewalls of the second through hole on the first through hole side, the sidewalls of the second through hole on the third through hole side, and the sidewalls of the third through hole on the second through hole side are set to 12 ,θ 21 ,θ 22 and θ 31 The taper angle θ of the side wall of the first through hole opposite to the second through hole and the side wall of the third through hole opposite to the second through hole is set to 20 degrees. 11 and θ 32 Set to 0 degrees.

[0161] The contact angle of the coating liquid with respect to the surface made of resin is 40 degrees, and the contact angle of the coating liquid with respect to the inorganic cover layer 35 is 9.7 degrees. The viscosity of the coating liquid is 0.0416 kg / m·s, and the density is 998 kg / m 3, surface tension is 0.027 N / m, flow rate is 0.01 m / sec. In addition, this flow rate is equivalent to the relative movement speed of the structure and the slot die along the Y direction when the coating liquid is applied to the surface of the structure before the wavelength conversion layer is formed in the wavelength conversion substrate 3.

[0162] (Example 2)

[0163] In addition to setting the taper angle θ of the side wall of the first through hole opposite to the second through hole and the side wall of the third through hole opposite to the second through hole 11 and θ 32 The simulation was performed under the same conditions as in Example 1 except that the temperature was changed to 20 degrees.

[0164] (Example 3)

[0165] In addition to the cone angle θ 12 ,θ 21 ,θ 22 and θ 31 The simulation was performed under the same conditions as in Example 1 except that the angle was changed to 5 degrees.

[0166] (Example 4)

[0167] In addition to the cone angle θ 12 ,θ 21 ,θ 22 and θ 31 The simulation was performed under the same conditions as in Example 1 except that the angle was changed to 10 degrees.

[0168] (Comparative Example 1)

[0169] In addition to the cone angle θ 12 ,θ 21 ,θ 22 and θ 31 The simulation was performed under the same conditions as in Example 1 except that the temperature was changed to 0 degrees.

[0170] (Comparative Example 2)

[0171] In addition to the cone angle θ 12 and θ 31 The simulation was performed under the same conditions as in Example 1 except that the temperature was changed to 0 degrees.

[0172] (Comparative Example 3)

[0173] In addition to the cone angle θ 21 and θ 22 The simulation was performed under the same conditions as in Example 1 except that the temperature was changed to 0 degrees.

[0174] (Comparative Example 4)

[0175] In addition to the cone angle θ11 and θ 32 Change the cone angle θ to 20 degrees. 12 ,θ 21 ,θ 22 and θ 31 The simulation was performed under the same conditions as in Example 1 except that the temperature was changed to 0 degrees.

[0176] <Evaluation>

[0177] The results of the above simulation are shown in Table 1 and Figures 7 to 14 shown.

[0178] [Table 1]

[0179]

[0180] According to Table 1 and Figures 7 to 14 The following situations can be known.

[0181] That is, according to Examples 1 to 4 and

[0182] As can be seen from the comparison of Comparative Examples 1 to 4, bubbles are less likely to be generated by making specific side walls among the side walls constituting the first to third through holes have a predetermined taper angle.

[0183] Based on the above, Examples 1 to 4 and Comparative Examples 1 to 4 were evaluated based on the following criteria.

[0184] [Evaluation A]

[0185] A decrease in brightness and color loss of a display device due to bubbles can be suppressed.

[0186] [Evaluation B]

[0187] The bubbles may cause a decrease in brightness or color loss in the display device.

[0188] Description of Reference Numerals

[0189] 1: display device, 2: dimming substrate, 3: wavelength conversion substrate, 4: adhesive layer, 21: substrate, 22: semiconductor layer, 23A: conductor layer, 23B: conductor layer, 23C: conductor layer, 23D: conductor layer, 24A: insulating layer, 24B: insulating layer, 24C: insulating layer, 25: light-emitting element, 26: partition layer, 27: filling layer, 28: conductor layer, 31: transparent substrate, 32: black matrix, 33G: second coloring layer, 33R: first coloring layer, 33B: base layer; 34: resin layer, 35: inorganic Cover layer, 36B: filling layer, 36G: second wavelength conversion layer, 36R: first wavelength conversion layer, 251: first layer, 252: second layer, 253: third layer, C: capacitor, D: light emitting element, DR: drive control element, L: light, PSL: power line, PX: pixel, PXB: third sub-pixel, PXG: second sub-pixel, PXR: first sub-pixel, SDR: scan signal line driver, SSL: scan signal line, SW: switch, VDR: image signal line driver, VSL: image signal line, W x 1: Distance, W x 2: Distance, W y 1: distance, L1: distance, L2: distance, L3: distance, W1: distance, W2: distance, W3: distance.

Claims

1. A wavelength conversion substrate, comprising: A transparent substrate having a first main surface and a second main surface; The resin layer is disposed on the first main surface and has a plurality of through hole groups including a first through hole, a third through hole, and a second through hole located therebetween; an inorganic covering layer, comprising a plurality of first portions respectively and at least partially covering side walls of the first to third through holes; as well as The wavelength conversion layer includes a plurality of wavelength conversion parts respectively disposed in at least a portion of the first to third through holes, The taper angle θ of the side wall of the first through hole on the second through hole side 12 , the taper angle θ of the side wall of the second through hole on the first through hole side 21 , the taper angle θ of the side wall of the second through hole on the third through hole side 22 , and a taper angle θ of a side wall of the third through hole on the second through hole side 31 , respectively, in the range of 3 to 40 degrees, The openings on the transparent substrate side of each of the first to third through holes are such that a ratio W1 / L1 of a dimension W1 in a first direction in which the first to third through holes are arranged to a dimension L1 in a second direction perpendicular to the first direction is in a range of 0.01 to 0.95, and the dimension L1 is in a range of 10 to 1000 μm.

2. The wavelength conversion substrate according to claim 1, wherein: The taper angle θ of the side wall of the first through hole on the side opposite to the second through hole side 11 , and a taper angle θ of the side wall of the third through hole on the side opposite to the second through hole side 32 , respectively in the range of 0 to 40 degrees.

3. The wavelength conversion substrate according to claim 2, wherein: The cone angle θ 11 and θ 32 are respectively smaller than the cone angle θ 12 ,θ 21 ,θ 22 and θ 31 Any one of .

4. The wavelength conversion substrate according to claim 2 or 3, wherein: The cone angle θ 11 and θ 32 is 0 degrees.

5. The wavelength conversion substrate according to any one of claims 1 to 4, wherein: The inorganic cover layer further includes a plurality of second portions, each extending at the position of the openings of the first to third through holes on the transparent substrate side and each having a fourth through hole smaller in size than the opening.

6. The wavelength conversion substrate according to claim 5, wherein: The ratio W1 / L1 is in the range of 0.01 to 0.75, and the ratio L2 / L1 of the dimension L2 of the fourth through hole in the second direction to the dimension L1 is in the range of 0.01 to 0.

80.

7. The wavelength conversion substrate according to any one of claims 1 to 6, wherein: The inorganic cover layer further includes a third portion that at least partially covers the upper surface of the resin layer and is adjacent to the first portion.

8. The wavelength conversion substrate according to any one of claims 1 to 7, wherein: The depth of each of the first to third through holes is in the range of 10 to 40 μm.

9. The wavelength conversion substrate according to any one of claims 1 to 8, wherein: The inorganic covering layer is made of metal or alloy.

10. The wavelength conversion substrate according to any one of claims 1 to 9, wherein: The invention further includes a black matrix interposed between the transparent substrate and the resin layer, and having a plurality of fifth through holes at the positions of the first to third through holes, respectively.

11. The wavelength conversion substrate according to claim 10, wherein: The ratio W1 / L1 is in the range of 0.01 to 0.75, and the ratio L3 / L1 of the dimension L3 of the fifth through hole in the second direction to the dimension L1 is in the range of 0.01 to 0.

80.

12. The wavelength conversion substrate according to claim 10 or 11, wherein: A color filter is further provided, the color filter including a plurality of colored layers each disposed at a position at least partially of the plurality of fifth through holes.

13. A display device comprising: The wavelength conversion substrate according to any one of claims 1 to 12; and A dimming device is disposed so as to face the first main surface.

14. The display device according to claim 13, wherein: The dimming device includes a substrate and a plurality of light emitting diodes arranged on the substrate corresponding to the first to third through holes.

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