Micro LED element substrate and display device

Abstract

A micro-LED element substrate is a micro-LED element substrate on which wiring (60), a first insulating layer (52) and a micro-LED element (14R) are arranged in sequence from the substrate (1) side, and the micro-LED element (14R) overlaps with the wiring (60). In a portion between the first insulating layer (52) and the micro-LED element (14R), a light shielding layer (61R) that crosses at least a portion of the wiring (60) located directly below the micro-LED element (14R) is located at a position that does not overlap with the positive electrode (14Ra) and the negative electrode (14Rb).

Description

Technical Field

[0001] The present disclosure relates to a micro LED element substrate having a micro LED (Light Emitting Diode) element and a display device using the micro LED element substrate. Background Art

[0002] Patent Document 1 discloses an example of the prior art.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Re-publication of Patent No. WO2015 / 114721 Summary of the invention

[0006] The micro LED element substrate disclosed in the present invention has the following structure, that is, a micro LED element substrate on which wiring, an insulating layer and a micro LED element are arranged in sequence from the substrate side, and the micro LED element overlaps with the wiring, the micro LED element has a positive electrode and a negative electrode separated when viewed from above, and in a portion between the insulating layer and the micro LED element, a light shielding layer that crosses at least a portion of the wiring located directly below the micro LED element is located at a position that does not overlap with the positive electrode and the negative electrode.

[0007] The display device disclosed in the present invention has the following structure, that is, it is a display device having the above-mentioned micro-LED element substrate of the present invention, wherein the substrate has: a configuration surface for configuring a pixel portion including the micro-LED element, an opposite surface on the side opposite to the configuration surface, and a side surface, the micro-LED element substrate has: a side wiring configured on the side surface, and a driving portion configured on the opposite surface side, a plurality of pixel portions in the pixel portion are configured in a matrix, and the micro-LED element is connected to the driving portion via the side wiring. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The objects, features and advantages of the present disclosure will become more apparent from the following detailed description and accompanying drawings.

[0009] Figure 1A This is a diagram showing an example of an embodiment of the micro LED element substrate of the present disclosure, and is a top view of a pixel portion of a micro LED element having three primary colors.

[0010] Figure 1B A diagram showing an example of an embodiment of the micro LED element substrate disclosed in the present invention is Figure 1A A cross-sectional view taken along the C1-C2 line as viewed from the forward viewing direction.

[0011] Figure 2A This is a diagram showing another example of an embodiment of the micro LED element substrate of the present disclosure, and is a cross-sectional view of a structure having a light-shielding layer having light scattering or light reflective properties directly below the micro LED element during laser irradiation.

[0012] Figure 2B This is a diagram showing another example of an embodiment of the micro LED element substrate of the present disclosure, and is a cross-sectional view of a structure having a light-shielding layer having light scattering or light reflective properties directly below the micro LED element during driving.

[0013] Figure 3 This is a diagram showing another example of an embodiment of the micro LED element substrate of the present disclosure, and is a cross-sectional view of a structure having a light shielding layer directly below the micro LED element.

[0014] Figure 4A This is a diagram showing another example of an embodiment of the micro LED element substrate of the present disclosure, and is a cross-sectional view of a structure having a light shielding layer and a heat diffusion layer directly below the micro LED element.

[0015] Figure 4B FIG. 1 is a diagram showing another example of the micro LED element substrate of the present disclosure, and is similar to FIG. Figure 4A A cross-sectional view of a structure having the same structure but with an insulating layer between the light shielding layer and the heat diffusion layer.

[0016] Figure 5 This is a diagram showing an example of an embodiment of the display device of the present disclosure, and is a plan view of the opposite surface of the micro LED element substrate.

[0017] Fig. 6A 1 is a diagram showing an example of a display device having a structure that is a basis for the display device of the present disclosure, and is a circuit block diagram of a basic structure of the display device.

[0018] Figure 6B is a diagram showing an example of a display device having a structure based on the display device of the present disclosure, Fig. 6A Cross-sectional view at line A1-A2.

[0019] Fig. 7A yes Fig. 6A , Figure 6B An enlarged top view of a pixel portion in a display device.

[0020] Figure 7B is with Fig. 7A A circuit diagram of a pixel portion having the same structure and a micro LED element with three primary colors.

[0021] Fig. 8A This is an enlarged plan view of one pixel portion in a display device having another structure as a basis for the display device of the present disclosure.

[0022] Figure 8B is with Fig. 8A A circuit diagram of a pixel portion having the same structure and a micro LED element with three primary colors.

[0023] Fig.9A It is shown Figure 8B The figure showing the specific structure of the pixel portion of the structure is a top view of the pixel portion.

[0024] Fig. 9B It is shown Figure 8B The specific structure of the pixel portion of the structure is shown in FIG. Fig.9A A cross-sectional view taken along the B1-B2 line as viewed from the forward viewing direction. DETAILED DESCRIPTION

[0025] Hereinafter, the embodiments of the micro LED element substrate and the display device disclosed in the present invention will be described with reference to the accompanying drawings. However, the drawings referred to below show the main structural components of the micro LED element substrate and the display device of the present embodiment. Therefore, the micro LED element substrate and the display device of the present embodiment may also have known structural components such as circuit substrates, wiring conductors, control ICs, LSIs, etc. that are not shown in the drawings.

[0026] First, refer to Figures 6A to 9B , a display device having a structure based on the display device of the present disclosure is described.

[0027] As a display device with a structure based on the display device of the present disclosure, there are known micro LED element substrates having micro LED elements, and self-luminous display devices that use the micro LED element substrates and do not require a backlight device. Fig. 6A A circuit block diagram showing the basic structure of such a display device is shown. Figure 6B Show Fig. 6AA cross-sectional view taken along the A1-A2 line of FIG. The display device has the following structure, namely, it comprises: a substrate 1 such as a glass substrate; a scanning signal line 2 arranged in a given direction (for example, a row direction) on the substrate 1; a light-emitting control signal line 3 arranged in a direction intersecting the given direction (for example, a column direction) so as to intersect the scanning signal line 2; an effective area (pixel area) 11 including a plurality of pixel portions (Pmn) 15 divided by the scanning signal line 2 and the light-emitting control signal line 3; and a plurality of light-emitting elements 14 arranged on an insulating layer. In order to reduce the frame portion 1g (shown in FIG. 6 ) around the effective area 11, there is a case where the following structure is set, namely, the scanning signal line 2 and the light-emitting control signal line 3 are connected via a side wiring 30 ( Fig. 6A The back wiring 9 is connected to the back wiring 9 located on the back of the substrate 1, and the back wiring 9 is connected to the driving unit 6 of the driving element such as IC and LSI provided on the back of the substrate 1. In this case, the display of the display device is driven and controlled by the driving unit 6 located on the back of the substrate 1. The driving unit 6 is mounted on the back side of the substrate 1 by a method such as COG (Chip On Glass).

[0028] Each pixel unit (Pmn) 15 is provided with a light emission control unit 22 for controlling the light emission, non-light emission, light emission intensity, etc. of the micro LED element (LDmn) 14 located in the light emission region (Lmn). The light emission control unit 22 includes a thin film transistor (TFT) 12 ( Fig. 7A As shown) and a TFT 13 (as a driving element for driving the micro LED element 14 with current according to a potential difference (light emitting signal) between a positive voltage (anode voltage: about 3 to 5 V) and a negative voltage (cathode voltage: about -3 V to 0 V) ​​corresponding to the level (voltage) of the light emitting control signal (the signal transmitted in the light emitting control signal line 3) Fig. 7A A capacitor is arranged on a connection line connecting the gate electrode and the source electrode of TFT13, and the capacitor functions as a holding capacitor for holding the voltage of the light emission control signal input to the gate electrode of TFT13 until the next rewriting (a period of one frame).

[0029] The micro LED element 14 is provided through the insulating layer 31 ( Figure 6B The through-holes or the like of the through-conductors 23a, 23b (shown) Fig. 7A), and is electrically connected to the light emission control unit 22, the positive voltage input line 16, and the negative voltage input line 17. That is, the positive electrode of the micro LED element 14 is connected to the positive voltage input line 16 via the positive electrode pad disposed on the substrate 1, the through conductor 23a, and the light emission control unit 22, and the negative electrode of the micro LED element 14 is connected to the negative voltage input line 17 via the negative electrode pad disposed on the substrate 1 and the through conductor 23b.

[0030] In addition, the display device has a frame portion 1g ( Fig. 6A As shown in FIG. 1 , there is a case where a light-emission control signal line driving circuit, a scanning signal line driving circuit, etc. are configured in the frame portion 1g.

[0031] In addition, if Figure 7B As shown, one pixel unit (PRGB11) 15a includes a red micro LED element (LDR11) 14R emitting red light, a green micro LED element (LDG11) 14G emitting green light, and a blue micro LED element (LDB11) 14B emitting blue light. By arranging a plurality of pixel units 15a in a matrix, a display device capable of color display can be formed. In this case, in order to make the pixel unit 15a as small as possible and to form a high-definition and high-resolution display device, there is a case where the following structure is set, that is, below the red micro LED element 14R, the green micro LED element 14G, and the blue micro LED element 14B, the light emission control units 22r, 22g, and 22b are arranged through an insulating layer. Furthermore, there is a case where the structure is set as follows, that is, below the red micro LED element 14R, etc., the positive voltage input line 16 and the negative voltage input line 17 are arranged through the insulating layer, and at least one of the positive voltage input line 16 and the negative voltage input line 17 overlaps with the red micro LED element 14R, etc. when viewed from above. Figure 7B In this case, the negative voltage input line 17 overlaps with the red micro LED element 14R and the blue micro LED element 14B when viewed from above, but according to the wiring structure, there is also a situation where the wiring that constitutes the light-emitting control unit 22r, 22g, and 22b, and the wiring connecting the red micro LED element 14R and the light-emitting control unit 22r overlap with the red micro LED element 14R.

[0032] In addition, Figure 7BIn the embodiment, the light emission intensity of the red micro LED element 14R is controlled by the light emission control signal line 3R, the light emission intensity of the green micro LED element 14G is controlled by the light emission control signal line 3G, and the light emission intensity of the blue micro LED element 14B is controlled by the light emission control signal line 3B. The red micro LED element 14R is electrically connected to the light emission control unit 22r, the positive voltage input line 16, and the negative voltage input line 17 via the through conductors 23ar and 23br. The green micro LED element 14G is electrically connected to the light emission control unit 22g, the positive voltage input line 16, and the negative voltage input line 17 via the through conductors 23ag and 23bg. The blue micro LED element 14B is electrically connected to the light emission control unit 22b, the positive voltage input line 16, and the negative voltage input line 17 via the through conductors 23ab and 23bb.

[0033] Fig. 8A as well as Figure 8B FIG. 2 shows a structure in which the light emission control unit 22 (22r, 22g, 22b) is arranged closer to the center of the substrate 1 than the micro LED element 14 (14R, 14G, 14B). Figure 8B As shown, one pixel unit (PRGBI1) 15b includes a red micro LED element 14R, a green micro LED element 14G, and a blue micro LED element 14B. By arranging a plurality of pixel units 15b in a matrix, a display device capable of color display can be formed. Figure 7B For the same purpose as the case of the above, there is a case where a light emitting control unit 22r is arranged below the red micro LED element 14R etc. through an insulating layer. Furthermore, there is a case where a positive voltage input line 16 and a negative voltage input line 17 are arranged below the red micro LED element 14R etc. through an insulating layer, and at least one of the positive voltage input line 16 and the negative voltage input line 17 overlaps with the red micro LED element 14R etc. when viewed from above. Figure 8B In this case, the positive voltage input line 16 overlaps with the red micro LED element 14R and the blue micro LED element 14B when viewed from above, but depending on the wiring structure, there is also a situation where the wiring that constitutes the light-emitting control unit 22r, etc., and the wiring that connects the red micro LED element 14R, etc. and the light-emitting control unit 22r, etc. overlap with the red micro LED element 14R, etc.

[0034] Fig.9A as well as Fig. 9B It is shown Figure 8B The specific structure diagram, Fig.9A is a top view of the pixel portion 15b. Fig. 9B yes Fig.9A The cross-sectional view of the B1-B2 line. Fig.9AAs shown, the positive electrode of the red micro LED element 14R is connected to the positive electrode pad 40ar arranged on the substrate 1 via a conductive connecting member such as solder or ACF (Anisotropic Conductive Film), and the negative electrode of the red micro LED element 14R is connected to the negative electrode pad 40br arranged on the substrate 1 via a conductive connecting member. Thus, the red micro LED element 14R is mounted on the substrate 1. In addition, a positive electrode pad 41ar and a negative electrode pad 41br for mounting a replacement red micro LED element 14Rr in the event that the red micro LED element 14R becomes defective are arranged at a portion adjacent to the red micro LED element 14R on the substrate 1. The positive electrode of the green micro LED element 14G is connected to the positive electrode pad 40ag arranged on the substrate 1 via a conductive connecting member, and the negative electrode of the green micro LED element 14G is connected to the negative electrode pad 40bg arranged on the substrate 1 via a conductive connecting member. Thus, the green micro LED element 14G is mounted on the substrate 1. In addition, a positive electrode pad 41ag and a negative electrode pad 41bg are provided at a portion adjacent to the green micro LED element 14G on the substrate 1 for mounting a replacement green micro LED element 14Gr when the green micro LED element 14G becomes defective. The positive electrode of the blue micro LED element 14B is connected to the positive electrode pad 40ab arranged on the substrate 1 via a conductive connecting member, and the negative electrode of the blue micro LED element 14B is connected to the negative electrode pad 40bb arranged on the substrate 1 via a conductive connecting member. Thus, the blue micro LED element 14B is mounted on the substrate 1. In addition, a positive electrode pad 41ab and a negative electrode pad 41bb are provided at a portion adjacent to the blue micro LED element 14B on the substrate 1 for mounting a replacement blue micro LED element 14Br when the blue micro LED element 14B becomes defective.

[0035] like Fig. 9BAs shown, an insulating layer 51, a positive voltage input line 16, insulating layers 52, 53 are sequentially stacked on the substrate 1 from the substrate 1 side. The insulating layers 51 to 53 include inorganic insulating layers such as silicon oxide (SiO2) and silicon nitride (Si3N4), and organic insulating layers such as acrylic resin and polycarbonate. A positive electrode pad 40ar and a negative electrode pad 40br are arranged at a portion (a portion of the bottom surface of the opening) where the insulating layer 52 is exposed in the opening provided in the insulating layer 53. The positive electrode pad 40ar and the negative electrode pad 40br each include a metal layer such as a Mo layer / Al layer / Mo layer (indicating a stacked structure in which an Al layer and a Mo layer are sequentially stacked on a Mo layer) and a transparent conductive layer such as ITO (Indium Tin Oxide) covering each metal layer. The positive electrode 14Ra of the red micro LED element 14R is connected to the positive electrode pad 40ar, and the negative electrode 14Rb is connected to the negative electrode pad 40br.

[0036] In addition, as another structure based on the display device of the present invention, the following image display device is proposed, which comprises: a first pixel circuit, having a gate electrode formed on a substrate, a semiconductor layer formed with an insulating layer sandwiched on the gate electrode, and a driving transistor including a pair of source-drain electrodes formed on the semiconductor layer and driving an organic EL element arranged in a pixel; a second pixel circuit, adjacent to the first pixel circuit; a pixel electrode, formed above the second pixel circuit and electrically connected to any one of a pair of source-drain electrodes of the driving transistor of the first pixel circuit; and a top metal electrode, electrically connected to any one of the pair of source-drain electrodes, disposed below the pixel electrode, and formed to cover the entire area of ​​at least the channel area of ​​the semiconductor layer from above (for example, refer to patent document 1).

[0037] Figure 1A to Figure 5 is a diagram showing a micro LED element substrate of this embodiment. Figure 1A as well as Figure 1BAs shown, the micro LED element substrate has the following structure, that is, it is a micro LED element substrate on which a wiring 60, a first insulating layer 52 as an insulating layer, and a micro LED element 14R are sequentially arranged from the substrate 1 side, and the micro LED element 14R overlaps with the wiring 60, and in the portion between the first insulating layer 52 and the micro LED element 14R, a light shielding layer 61 (61R) that crosses at least a portion of the wiring 60 located directly below the micro LED element 14R is located at a position that does not overlap with the positive electrode 14Ra and the negative electrode 14Rb. The above structure can achieve the following effects. In a case where the micro LED element 14R is in a defective state such as not being able to obtain the required luminous intensity and being unable to light up due to reasons such as a defective product having a poor connection, when the connecting wiring 40al (for example, Figure 1B The portion between the through conductor 23ar and the positive electrode pad 40ar indicated by the symbol D) and / or the connection wiring 40b1 connected to the negative electrode 14Rb (for example, Figure 1B When the laser LR reaches the wiring 60 and erroneously damages the wiring 60 or erroneously cuts the wiring 60, it is possible to prevent the laser LR from reaching the wiring 60 and causing the wiring 60 to be damaged or cut off. In addition, it is possible to prevent the wiring 60 and the first insulating layer 52 from being peeled off at the interface due to the heat of the laser LR, thereby causing the flatness of the outermost surface of the substrate 1 to deteriorate.

[0038] The wiring 60 is a drive wiring or the like electrically connected to the positive voltage input line 16 , the negative voltage input line 17 , or the micro LED element 14R.

[0039] In the micro LED element substrate of the present embodiment, the substrate 1 can be a translucent substrate such as a glass substrate, a plastic substrate, or a non-translucent substrate such as a ceramic substrate, a non-translucent plastic substrate, or a metal substrate. Furthermore, it can also be a composite substrate in which a glass substrate and a plastic substrate are stacked, a composite substrate in which a glass substrate and a ceramic substrate are stacked, a composite substrate in which a glass substrate and a metal substrate are stacked, or other composite substrates in which a plurality of substrates of different materials among the above-mentioned various substrates are stacked. In addition, in the substrate 1, a glass substrate, a plastic substrate, a ceramic substrate, or the like, which is an electrically insulating substrate, is preferred in terms of the ease of forming wiring. In addition, the shape of the substrate 1 when viewed from above can be various shapes such as a rectangular shape, a circular shape, an elliptical shape, a trapezoidal shape, or the like.

[0040] The micro LED element 14R used in the micro LED element substrate of this embodiment is a self-luminous element that does not require a backlight and has high luminous efficiency and a long life. Figure 1BAs shown, the micro LED element 14R is a horizontal element in which the positive electrode 14Ra and the negative electrode 14Rb are separated from each other in a plan view and arranged on the side of the substrate 1. The horizontal micro LED element 14R has a light emitting portion 14RL in the center between the positive electrode 14Ra and the negative electrode 14Rb in a plan view. The positive electrode 14Ra is connected to the positive electrode pad 40ar arranged on the substrate 1 via a conductive connecting member such as solder, and the negative electrode 14Rb is connected to the negative electrode pad 40br arranged on the substrate 1 via a conductive connecting member.

[0041] In addition, the micro LED element 14R may be disposed on the configuration surface 1a ( Figure 6B In this case, for example, a positive electrode, a light-emitting layer, and a negative electrode are stacked from the configuration surface 1a side.

[0042] When the micro LED element 14R is rectangular in plan view, the length of one side is about 1 μm to about 100 μm, more specifically about 3 μm to about 10 μm, but the size is not limited to these.

[0043] like Figure 1A As shown, in a pixel portion (PRGB11) 15b, micro LED elements 14R, 14G, and 14B having different luminous colors may also be configured. For example, the luminous color of the micro LED element 14R may be set to red, orange, orange-red, purple-red, and purple, the luminous color of the micro LED element 14G may be set to green or yellow-green, and the luminous color of the micro LED element 14B may be set to blue. As a result, it becomes easy to use a micro LED element substrate to produce a display device capable of color display. In addition, when there are three or more micro LED elements 14 (hereinafter, when the micro LED element 14R and the like are collectively referred to as the micro LED element 14), a plurality of elements having the same luminous color may also be included.

[0044] A micro LED element 14Rr is disposed adjacent to the micro LED element 14R as a replacement when the micro LED element 14R becomes poorly luminous or cannot emit light. With respect to the micro LED element 14Rr, its positive electrode is connected to the positive electrode pad 41ar, and its negative electrode is connected to the negative electrode pad 41br. Similarly, a micro LED element 14Gr is disposed adjacent to the micro LED element 14G as a replacement when the micro LED element 14G becomes poorly luminous or cannot emit light. With respect to the micro LED element 14Gr, its positive electrode is connected to the positive electrode pad 41ag, and its negative electrode is connected to the negative electrode pad 41bg. Similarly, a micro LED element 14Br is disposed adjacent to the micro LED element 14B as a replacement when the micro LED element 14B becomes poorly luminous or cannot emit light. With respect to the micro LED element 14Br, its positive electrode is connected to the positive electrode pad 41ab, and its negative electrode is connected to the negative electrode pad 41bb.

[0045] The wiring 60, the positive electrode 14Ra, and the negative electrode 14Rb include, for example, a conductor layer of tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), chromium (Cr), silver (Ag), copper (Cu), etc. In addition, the wiring 60, the positive electrode 14Ra, and the negative electrode 14Rb may also include a metal layer having a Mo layer / Al layer / Mo layer (indicating a stacked structure in which an Al layer and a Mo layer are sequentially stacked on a Mo layer), and further, may include a metal layer such as an Al layer, an Al layer / Ti layer, a Ti layer / Al layer / Ti layer, a Mo layer, a Mo layer, a Mo layer / Al layer / Mo layer, a Ti layer / Al layer / Mo layer, a Mo layer, a Mo layer / Al layer / Mo layer, a Mo layer / Al layer / Ti layer, a Cu layer, a Cr layer, a Ni layer, and an Ag layer.

[0046] The positive electrode pad 40ar and the negative electrode pad 40br can also be configured to have the same structure as the wiring 60, the positive electrode 14Ra, and the negative electrode 14Rb. In addition, the positive electrode pad 40ar and the negative electrode pad 40br can also be covered by a transparent conductive layer containing a conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide with silicon oxide added (ITSO), zinc oxide (ZnO), silicon (Si) containing phosphorus and boron, and having transparency.

[0047] The pixel unit 15b includes a plurality of micro LED elements 14R, 14G, and 14B that emit light of different colors, and these function as display units. For example, in the case of a display device for color display, a micro LED element 14R that emits red light, a micro LED element 14G that emits green light, and a micro LED element 14B that emits blue light constitute a pixel unit capable of color grayscale display.

[0048] It is preferable that the plurality of micro LED elements 14R, 14G, and 14B included in one pixel portion 15b are arranged not in a straight line when viewed from above. In this case, the size of the pixel portion 15b when viewed from above becomes smaller, and the shape of the pixel portion 15b when viewed from above can be a compact square shape, etc. As a result, in a display device, etc., the pixel density is improved, and pixel unevenness is less likely to occur, so that high-quality image display can be performed.

[0049] In the pixel portion 15b, a light-emitting control portion including TFTs as switching elements and control elements for controlling the light emission, non-light emission, light emission intensity, etc. of the micro-LED elements 14R, 14G, and 14B may also be provided. In this case, the light-emitting control portion may also be provided below the micro-LED elements 14R, 14G, and 14B via an insulating layer. In this case, the size of the pixel portion 15b when viewed from above becomes smaller, and the shape of the pixel portion 15b when viewed from above can be a small square shape, etc. As a result, in a display device, etc., the pixel density is increased, and pixel unevenness is less likely to occur, so that high-quality image display can be performed.

[0050] In the micro LED element substrate of the present embodiment, it is preferable that the light shielding layer 61R covers the entire wiring 60 located directly below the micro LED element 14R. In this case, the light shielding layer 61R with a wide area can more effectively prevent the laser LR from reaching the wiring 60 and erroneously damaging or cutting the wiring 60. In addition, it can more effectively prevent the occurrence of a situation in which the interface between the wiring 60 and the first insulating layer 52 is peeled off due to the heat of the laser LR, resulting in deterioration of the flatness of the outermost surface of the substrate 1.

[0051] In addition, if Figure 1A As shown, the light shielding layer 61R preferably covers the micro LED element 14R when viewed from above, in other words, preferably includes the micro LED element 14R when viewed from above. In this case, the light shielding layer 61R with a wider area can more effectively prevent the laser LR from reaching the wiring 60 and erroneously damaging or cutting the wiring 60. In addition, it can more effectively prevent the occurrence of a situation in which the interface between the wiring 60 and the first insulating layer 52 is peeled off due to the heat of the laser LR, resulting in the flatness of the outermost surface of the substrate 1 being deteriorated.

[0052] In addition, the light shielding layer 61G may be disposed below the micro LED element 14G, and the light shielding layer 61B may be disposed below the micro LED element 14B. The light shielding layers 61G and 61B may be variously implemented similarly to the light shielding layer 61R.

[0053] In addition, in the micro LED element substrate of the present embodiment, the light shielding layer 61R may also present a dark color such as black, dark brown, dark blue, etc. In this case, the light shielding layer 61R can be formed by mixing dark color pigments, dyes, ceramic particles, plastic particles, metal particles, etc. into a resin layer containing an organic resin such as acrylic resin and polycarbonate. In particular, in terms of resistance to high-output lasers such as YAG lasers, a resin layer containing more than 50 volume % of pigments, ceramic particles, and metal particles is preferred. In addition, the light shielding layer 61R may also contain more than 50 volume % of pigments, ceramic particles, and metal particles in an inorganic insulating layer such as SiO2 and Si3N4.

[0054] In addition, the light shielding layer 61R can also be formed to have a dark color by setting at least the surface layer thereof to a chromium (Cr) layer, a carbon layer, a layer containing carbon, etc. For example, the base layer of the light shielding layer 61R can be formed by a conductor layer having a metallic luster such as tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), silver (Ag), copper (Cu), etc., and a chromium (Cr) layer, a carbon layer, or a layer containing carbon can be formed as a surface layer on the base layer.

[0055] In addition, the light shielding layer 61R may be a metal layer including tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), silver (Ag), copper (Cu), etc. In addition, the light shielding layer 61R may also be a composite layer in which a plurality of layers including these materials are stacked. For example, the light shielding layer 61R may be a Mo layer / Al layer / Mo layer.

[0056] In addition, when the light shielding layer 61R is a conductor layer such as the metal layer mentioned above, it can also be connected to the power supply line of the positive voltage input line 16 and the negative voltage input line 17. When the light shielding layer 61R is connected to the power supply line, the area of ​​the power supply line increases, thereby exerting an effect such as stabilizing the power supply voltage. Furthermore, when the light shielding layer 61R is a conductor layer such as the metal layer mentioned above, it can also be connected to a line (for example, the negative voltage input line 17) that serves as a ground potential among the positive voltage input line 16 and the negative voltage input line 17. In this case, the ground potential is stabilized, resulting in an effect such as a more stable power supply voltage. In addition, the light shielding layer 61R may not be connected to the power supply line, etc., but may be in an electrically floating state.

[0057] In order to effectively suppress the direct influence of the laser LR on the wiring 60, such as damage, and the indirect influence of heat, the thickness of the light shielding layer 61R is preferably about 100nm to 1000nm (1μm). More preferably, the thickness of the light shielding layer 61R is preferably about 300nm to 1000nm. Moreover, the thickness of the light shielding layer 61R is preferably thicker than the thickness of the wiring 60 (about 50 to 200nm). In this case, the light shielding layer 61R can more effectively suppress the direct influence of the laser LR on the wiring 60, such as damage, and the indirect influence of heat.

[0058] In addition, if Figure 2A as well as Figure 2B As shown, in the micro LED element substrate of this embodiment, the light shielding layer 61R preferably has light scattering or light reflecting properties. Figure 2A In this way, the laser light LR can be scattered or reflected toward the micro LED element 14R by the light shielding layer 61R, so that the light shielding layer 61R has a higher light shielding property. Figure 2B As shown, in a display device having a micro LED element substrate, when the micro LED element 14R is driven, the light LE radiated from the light emitting portion 14RL of the micro LED element 14R can be scattered or reflected toward the side of the micro LED element 14R through the light shading layer 61R, thereby also achieving the effect of improving the brightness and contrast of the displayed image.

[0059] The light-scattering shading layer 61R can be formed, for example, by roughening the surface of a conductor layer having a metallic luster such as tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), silver (Ag), copper (Cu), etc. In this case, the arithmetic mean roughness of the surface of the light-shielding layer 61R is preferably 50 μm or less, and more preferably, 1 μm or more and 10 μm or less. As a method for roughening the surface of the light-shielding layer 61R, a method of etching the surface of the light-shielding layer 61R such as dry etching can be adopted, and a method of forming a particle structure such as giant single crystal particles and giant polycrystalline particles in the light-shielding layer 61R by controlling the film forming time, film forming temperature, etc. when forming the light-shielding layer 61R by a thin film forming method such as CVD (Chemical Vapor Deposition) can be adopted.

[0060] In addition, in the micro LED element substrate of the present embodiment, it is preferable that the light shielding layer 61R has light reflectivity. In this case, the laser light LR can be reflected toward the micro LED element 14R side, so that the light shielding layer 61R has a higher light shielding property. In addition, in a display device having a micro LED element substrate, when the micro LED element 14R is driven, the brightness and contrast of the displayed image are improved.

[0061] The light-reflective shielding layer 61R can be formed by smoothing the surface of a conductor layer having a metallic luster such as tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), silver (Ag), copper (Cu), etc. For this purpose, the arithmetic mean roughness of the surface of the light-shielding layer 61R is preferably 1 μm or less, more preferably 0.1 μm or less.

[0062] In addition, in the micro LED element substrate of this embodiment, Figure 3 As shown, the second insulating layer 54 as another insulating layer is interposed between the light shielding layer 61R and the micro LED element 14R, and the thickness d1 of the first insulating layer 52 is preferably thicker than the thickness d2 of the second insulating layer. That is, it is preferable that the light shielding layer 61R is located closer to the micro LED element 14R side than the wiring 60 side. In this case, the influence of the heat generated by the irradiation of the laser LR on the wiring 60 can be suppressed. As a result, it is possible to more effectively prevent the occurrence of peeling at the interface between the wiring 60 and the first insulating layer 52 due to the heat of the laser LR, and the flatness of the outermost surface of the substrate 1 is deteriorated. In addition, the second insulating layer 54 located closer to the micro LED element 14R than the light shielding layer 61R may also have a slight light shielding property and light absorption property. For example, the second insulating layer 54 may also be a slightly dark color such as gray, brown, navy blue, etc. In this case, the light shielding layer 61R can be formed by mixing dark-colored pigments, dyes, ceramic particles, plastic particles, metal particles, etc. into a resin layer containing an organic resin such as acrylic resin or polycarbonate. In particular, a resin layer containing pigments, ceramic particles, or metal particles is preferred in terms of resistance to high-output lasers such as YAG lasers. In addition, the light shielding layer 61R may also contain pigments, ceramic particles, or metal particles in an inorganic insulating layer such as SiO2 or Si3N4.

[0063] In addition, the first insulating layer 52 may be a laminate of multiple insulating layers, and the second insulating layer 54 may be a laminate of multiple insulating layers.

[0064] In addition, in the micro LED element substrate of this embodiment, Figure 4A as well as Figure 4B As shown, the heat diffusion layer 62 is preferably interposed between the first insulating layer 52 and the light shielding layer 61R. In this case, the light shielding property of the light shielding layer 61R can be further improved, and the influence of the heat generated by the irradiation of the laser LR on the wiring 60 can be further suppressed. The heat diffusion layer 62 includes a material such as tantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum (Al), silver (Ag), copper (Cu), etc., which is the same material as the light shielding layer 61R, and preferably includes a material having a thermal conductivity equal to or higher than that of the light shielding layer 61R.

[0065] In addition, if Figure 4B As shown, it is preferable that the third insulating layer 56 is interposed between the light shielding layer 61R and the heat diffusion layer 62. In this case, the influence of the heat generated by the irradiation of the laser beam LR on the wiring 60 can be further suppressed.

[0066] The first insulating layer 52, the second insulating layer 54, and the third insulating layer 56 include inorganic insulating layers such as silicon oxide (SiO2) and silicon nitride (Si3N4), and organic insulating layers such as acrylic resin and polycarbonate. In terms of resistance to laser LR, the first insulating layer 52, the second insulating layer 54, and the third insulating layer 56 preferably include inorganic insulating layers such as silicon oxide (SiO2) and silicon nitride (Si3N4).

[0067] like Figure 5 As shown, the display device of this embodiment has the following structure, that is, it is a display device having the micro LED element substrate of this embodiment, wherein the substrate 1 has: an arrangement surface 1a ( Figure 6B The opposite side 1b ( Figure 6B as shown); and side 1s ( Figure 6B As shown in the figure, the micro LED element substrate has: a side wiring 30 arranged on the side 1s; and a driving unit 6 arranged on the opposite side 1b, and a plurality of pixel units 15b are arranged in a matrix, and the micro LED element 14R is connected to the driving unit 6 via the side wiring 30. This structure has the following effects. Even if the micro LED element 14R is defective, it can be repaired by laser LR without damaging the wiring 60, etc., so that the display device has a long life. In addition, since the driving unit 6 is arranged on the opposite side 1b of the substrate 1, the frame portion 1g ( Fig. 6A as well as Figure 6B As a result, when a plurality of display devices are tiled (tiling) to form a multi-display, the seams between the display devices become less noticeable, and the display quality is improved.

[0068] The driving unit 6 may be a structure in which driving elements such as IC and LSI are mounted in a chip on glass (COG) method or a chip on film (COF) method, but may also be a circuit substrate equipped with driving elements. In addition, the driving unit 6 may also be a thin film circuit such as a TFT having a semiconductor layer including LTPS (Low Temperature Poly Silicon) directly formed by a thin film forming method such as a CVD method on the opposite surface 1b of the substrate 1 including the glass substrate.

[0069] The side wiring 30 can be formed by a method such as a photocuring method or a heating photocuring method, in which a conductive paste containing conductive particles such as silver (Ag), copper (Cu), aluminum (Al), stainless steel, uncured resin components, alcohol solvents, and water is cured by heating or irradiation with light such as ultraviolet rays. In addition, the side wiring 30 can also be formed by a thin film forming method such as a plating method, a vapor deposition method, or a CVD method. In addition, a groove may be provided at the position of the side surface 1s of the substrate 1 where the side wiring 30 is arranged. In this case, the conductive paste is easily arranged in the groove, which is the desired position of the side surface 1s.

[0070] Furthermore, the display device of this embodiment can also be configured as a light emitting device. The light emitting device can be used as a printer head, a lighting device, a signboard device, a notification device, a signal device, etc. used in an image forming device, etc.

[0071] When repairing the micro LED element substrate of this embodiment, the following method can be used. Figure 1A As shown, the following micro LED element substrate is prepared, that is, a wiring 60, a first insulating layer 52 and a first micro LED element 14R are arranged in order from the substrate 1 side on the substrate 1, and the wiring 60 overlaps with the first micro LED element 14R, the first micro LED element 14R has a positive electrode 14Ra and a negative electrode 14Rb separated when viewed from above, and a light shielding layer that crosses at least a portion of the wiring 60 located directly below the first micro LED element 14R at a location between the first insulating layer 52 and the first micro LED element 14R 61R is located at a position that does not overlap with the positive electrode 14Ra and the negative electrode 14Rb. Then, if the first micro LED element 14R becomes defective, the first micro LED element 14R is removed from the substrate 1, and when the connection wiring 40a1 connected to the positive electrode 14Ra of the first micro LED element 14R and / or the connection wiring 40b1 connected to the negative electrode 14Rb are cut by the laser LR, the connection wiring 40a1 is cut at a position where the irradiation position overlaps with the light shielding layer 61R, and then the second micro LED element 14Rr is arranged on the substrate 1. Thus, even if the first micro LED element 14R becomes defective, it can be repaired by the laser LR without damaging the wiring 60, etc., so that a display device with a long life can be manufactured.

[0072] In the above-mentioned repair method, the first micro LED element 14R has a positive electrode 14Ra and a negative electrode 14Rb separated from each other in a plan view on the substrate 1 side. When the connection wiring 40a1 connected to the positive electrode 14Ra of the first micro LED element 14R and / or the connection wiring 40b1 connected to the negative electrode 14Rb are cut by the laser LR, it is preferable to cut the portion between the positive electrode 14Ra and the negative electrode 14Rb. That is, when a dark layer such as a black matrix layer for setting the background color to a dark color such as black to improve the contrast is present in a portion other than the first micro LED element 14R in a plan view on the substrate 1, the dark layer becomes an obstacle and there is a concern that it is difficult to cut the connection wirings 40a1 and 40b1 by the laser LR. Therefore, when the connection wirings 40a1 and 40b1 are cut by the laser LR, when the portion between the positive electrode 14Ra and the negative electrode 14Rb is cut, the above-mentioned dark layer does not become an obstacle, so it can be easily cut.

[0073] In addition, the micro LED element substrate, display device, and micro LED element substrate repair method disclosed in the present invention are not limited to the above-mentioned embodiments, and may also include appropriate design changes and improvements. For example, when the substrate 1 is a non-light-transmissive substrate, the substrate 1 may also be a glass substrate colored in black, gray, or other colors, or a glass substrate including frosted glass.

[0074] The present disclosure may be the next embodiment.

[0075] The micro LED element substrate disclosed in the present invention has the following structure, that is, a micro LED element substrate on which wiring, an insulating layer and a micro LED element are arranged in sequence from the substrate side, and the micro LED element overlaps with the wiring, the micro LED element has a positive electrode and a negative electrode separated when viewed from above, and in a portion between the insulating layer and the micro LED element, a light shielding layer that crosses at least a portion of the wiring located directly below the micro LED element is located at a position that does not overlap with the positive electrode and the negative electrode.

[0076] The micro LED element substrate disclosed herein may be configured such that the light shielding layer covers the entire wiring directly below the micro LED element.

[0077] Furthermore, in the micro LED element substrate disclosed herein, the light shielding layer may have light scattering properties.

[0078] Furthermore, in the micro LED element substrate disclosed herein, the light shielding layer may have light reflectivity.

[0079] In addition, the micro LED element substrate disclosed in the present invention may also have another insulating layer interposed between the light shielding layer and the micro LED element, and the thickness of the insulating layer is thicker than the thickness of the other insulating layer.

[0080] The display device disclosed in the present invention has the following structure, that is, it is a display device having the above-mentioned micro-LED element substrate disclosed in the present invention, wherein the substrate has: a configuration surface on which a pixel portion including the micro-LED element is configured; an opposite surface on the side opposite to the configuration surface; and a side surface, the micro-LED element substrate has: a side wiring configured on the side surface; and a driving portion configured on the opposite surface side, a plurality of pixel portions in the pixel portion are configured in a matrix, and the micro-LED element is connected to the driving portion via the side wiring.

[0081] The micro LED element substrate disclosed in the present invention has the following structure, that is, a micro LED element substrate on which wiring, an insulating layer and a micro LED element are sequentially arranged from the substrate side, and the micro LED element overlaps with the wiring, the micro LED element has a positive electrode and a negative electrode separated when viewed from above, and a light shielding layer that crosses at least a portion of the wiring located directly below the micro LED element is located at a position that does not overlap with the positive electrode and the negative electrode in the area between the insulating layer and the micro LED element, thereby exerting the following effects. In the case where the micro LED element is in a bad state such as not being able to obtain the required luminous intensity and not being able to light up due to a defective product with poor connection, when the connection wiring connected to the positive electrode of the micro LED element and / or the connection wiring connected to the negative electrode is cut by laser, it is possible to prevent the laser from reaching the wiring and erroneously damaging the wiring or erroneously cutting the wiring. In addition, it is possible to prevent the occurrence of a situation in which peeling occurs at the interface between the wiring and the insulating layer due to the heat of the laser, resulting in deterioration of the flatness of the outermost surface on the substrate.

[0082] In the micro LED element substrate disclosed herein, when the light shielding layer covers the entire wiring located directly below the micro LED element, the wide light shielding layer can more effectively prevent the laser from reaching the wiring and erroneously damaging or cutting the wiring. In addition, it can more effectively prevent the wiring from being peeled off at the interface between the wiring and the first insulating layer due to the heat of the laser, resulting in the flatness of the outermost surface on the substrate being deteriorated.

[0083] In addition, in the micro-LED element substrate disclosed in the present invention, when the light shielding layer has light scattering properties, the laser light can be scattered toward the micro-LED element side, thereby forming a light shielding layer with higher light shielding properties. In addition, in a display device having a micro-LED element substrate, when the micro-LED element is driven, the brightness and contrast of the displayed image are improved.

[0084] In addition, in the micro-LED element substrate disclosed in the present invention, when the light shielding layer has light reflectivity, it is possible to reflect the laser light toward the micro-LED element side, thereby forming a light shielding layer with higher light shielding properties. In addition, in a display device having a micro-LED element substrate, when the micro-LED element is driven, the brightness and contrast of the displayed image are also improved.

[0085] Furthermore, in the micro LED element substrate of the present disclosure, when another insulating layer is interposed between the light shielding layer and the micro LED element, and the thickness of the other insulating layer is thicker than the thickness of the insulating layer, the influence of heat generated by laser irradiation on the wiring can be suppressed. As a result, it is possible to more effectively prevent the occurrence of a situation in which the interface between the wiring and the insulating layer is peeled off due to the heat of the laser and the flatness of the outermost surface on the substrate is deteriorated.

[0086] The display device disclosed in the present invention has the following structure, that is, it is a display device having the above-mentioned micro-LED element substrate disclosed in the present invention, the substrate having: a configuration surface for configuring a pixel portion including the micro-LED element; an opposite surface on the side opposite to the configuration surface; and a side surface, the micro-LED element substrate having: a side wiring configured on the side surface; and a driving portion configured on the opposite surface side, a plurality of the pixel portions are configured in a matrix, and the micro-LED element is connected to the driving portion via the side wiring, thereby exerting the following effects. Even if a micro-LED element is defective, it can be repaired by laser without damaging the wiring, etc., so that it becomes a display device with a long life. In addition, since the driving portion is configured on the opposite surface side of the substrate, the frame portion can be reduced. As a result, when a plurality of display devices are tiled to form a multi-display, the seams between the display devices become less noticeable, and the display quality becomes higher.

[0087] Industrial Applicability

[0088] The display device disclosed in the present invention can be applied to various electronic devices. As such electronic devices, there are composite and large display devices (multi-displays), automobile route guidance systems (automobile navigation systems), ship route guidance systems, aircraft route guidance systems, smart phone terminals, portable phones, tablet terminals, personal digital assistants (PDAs), video cameras, digital cameras, electronic notebooks, electronic books, electronic dictionaries, personal computers, copiers, terminal devices for game devices, televisions, product display labels, price display labels, industrial programmable display devices, car audio, digital audio players, fax machines, printers, automatic cash deposit and withdrawal machines (ATMs), vending machines, head-mounted displays (HMDs), digital display watches, smart watches, etc.

[0089] The present disclosure can be implemented in various other ways without departing from its spirit or main features. Therefore, the aforementioned embodiments are merely illustrative in all aspects, and the scope of the present disclosure is the scope indicated in the claims, and is not restricted by the main text of the specification. Furthermore, all modifications and changes belonging to the claims are within the scope of the present disclosure.

[0090] Explanation of symbols

[0091] 1: Substrate;

[0092] 1a: configuration surface;

[0093] 1b: opposite side;

[0094] 1s: side;

[0095] 6: driving part;

[0096] 14B, 14G: micro LED components;

[0097] 14R: micro LED element (first micro LED element);

[0098] 14Ra: positive electrode;

[0099] 14Rb: negative electrode;

[0100] 14RL: light-emitting part;

[0101] 14Rr: 2nd micro LED component;

[0102] 15a, 15b: pixel portion;

[0103] 30: Side wiring;

[0104] 40al, 40b1: connection wiring;

[0105] 40ar: positive electrode pad;

[0106] 40br: negative electrode pad;

[0107] 52: insulating layer (first insulating layer);

[0108] 54: other insulating layer (second insulating layer);

[0109] 60: Wiring;

[0110] 61, 61B, 61G, 61R: light-shielding layer.

Claims

1. A micro LED element substrate, on which wiring, an insulating layer and a micro LED element are sequentially arranged from the substrate side, and the micro LED element overlaps with the wiring, The micro LED element has a positive electrode and a negative electrode separated from each other in a plan view. A light shielding layer covering at least a portion of the wiring directly below the micro LED element exists between the insulating layer and the micro LED element at a position that does not overlap with the positive electrode and the negative electrode. The thickness of the light shielding layer is thicker than the thickness of the wiring, A heat diffusion layer having a higher thermal conductivity than the light shielding layer is interposed between the insulating layer and the light shielding layer. The heat diffusion layer is in close contact with the light shielding layer.

2. A micro LED element substrate, on which wiring, an insulating layer and a micro LED element are sequentially arranged from the substrate side, and the micro LED element overlaps with the wiring, The micro LED element has a positive electrode and a negative electrode separated from each other in a plan view. A light shielding layer that covers the entire wiring directly below the micro LED element exists between the insulating layer and the micro LED element. The thickness of the light shielding layer is thicker than the thickness of the wiring, A heat diffusion layer having a higher thermal conductivity than the light shielding layer is interposed between the insulating layer and the light shielding layer. The heat diffusion layer is in close contact with the light shielding layer.

3. The micro LED element substrate according to claim 1 or 2, wherein: The light shielding layer has light scattering properties.

4. The micro LED element substrate according to claim 1 or 2, wherein: The light shielding layer has light reflectivity.

5. The micro LED element substrate according to claim 1 or 2, wherein: Another insulating layer is interposed between the light shielding layer and the micro LED element. The thickness of the insulating layer is thicker than that of the other insulating layers.

6. A display device comprising the micro LED element substrate according to any one of claims 1 to 5, The substrate has: a configuration surface on which a pixel portion including the micro LED element is configured, an opposite surface opposite to the configuration surface, and a side surface. The micro LED element substrate includes: a side wiring arranged on the side surface, and a driving unit arranged on the opposite side surface. A plurality of pixel portions in the pixel portion are arranged in a matrix. The micro LED element is connected to the driving unit via the side wiring.

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