Display device

Abstract

The present invention prevents metal wiring from being visible due to light reflecting off the metal wiring in an LED display device. This display device 100 comprises: a backplane BP having an electrode 111 and an electrode 112; an LED element 114 disposed on the electrode 112 with a bump electrode 113 therebetween; and an insulating film 117 formed on the backplane BP. The bump electrode 113 is a black film.

Description

Display device

[0001] The present invention relates to a display device, and more particularly, to a technique effective when applied to a display device having light-emitting diode elements, for example.

[0002] Japanese Patent Application Laid-Open No. 2023-72871 (Patent Document 1) describes a technique related to a display device that can suppress light crosstalk between adjacent light-emitting elements while adopting a method in which a light-shielding partition is formed on a color conversion panel.

[0003] International Publication No. 2020 / 241,117 (Patent Document 2) describes a technique related to a light-emitting element mounting substrate that improves light extraction efficiency.

[0004] Japanese Patent Application Laid-Open No. 2023-72871International Publication No. 2020 / 241,117

[0005] There is an LED (Light Emitting Diode) display device that uses a plurality of light-emitting diode elements arranged on a substrate called a backplane as a light source. Basically, an LED display device has no structure to prevent reflection from wiring. Therefore, when not lit, for example, metal wiring may be visible due to reflection of light. Therefore, in an LED display device, a measure to suppress the visibility of metal wiring due to reflection of light is desired.

[0006] Other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

[0007] A display device according to an embodiment includes a backplane having a first electrode and a second electrode, a light-emitting diode element disposed on the second electrode via a bump electrode, and an insulating film formed on the backplane. The bump electrode is a black film, and the backplane has a metal wiring electrically connected to the first electrode. The display device has a first black pattern formed above the metal wiring and covering the metal wiring in a plan view.

[0008] This is a plan view showing an example of the configuration of a display device. This is a circuit diagram showing an example of the configuration of the circuit around a pixel. This is a plan view showing the main configuration of the display device in the embodiment. This is a cross-sectional view of the display device along line A-A in Figure 3. This is a diagram showing the manufacturing process of the display device in the embodiment. This is a diagram showing the manufacturing process of the display device following Figure 5. This is a diagram showing the manufacturing process of the display device following Figure 6. This is a diagram showing the manufacturing process of the display device following Figure 7. This is a diagram showing the manufacturing process of the display device following Figure 8.

[0009] The embodiments will be described below with reference to the drawings.

[0010] This disclosure is merely an example, and any modifications that maintain the spirit of this disclosure while being appropriately conceivable by a person skilled in the art are naturally included within the scope of this disclosure.

[0011] Furthermore, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc., of each part compared to the actual embodiment, but these are merely examples and do not limit the interpretation of this disclosure. In this specification and each drawing, elements similar to those shown in previously published drawings are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0012] In this embodiment, as an example of a display device using multiple light-emitting diode elements, a micro-LED display device equipped with multiple micro-LED elements is provided. Micro-LED elements have a smaller size (outer diameter) compared to general LED elements. Therefore, micro-LED display devices can display high-resolution images.

[0013] <Configuration of the display device> Figure 1 is a plan view showing an example of the configuration of a display device.

[0014] In Figure 1, the boundary between the display area DA and the peripheral area PFA, the control circuit 5, the drive circuit 6, and the multiple pixels PIX are each shown by dashed lines.

[0015] Figure 2 is a circuit diagram showing an example of the configuration of the circuit around a pixel shown in Figure 1. Note that the pixel circuit shown in Figure 2 is an example of an equivalent circuit corresponding to one pixel PIX shown in Figure 1.

[0016] Figure 1 shows the X and Y directions. The X and Y directions intersect each other. In the example described below, the X direction is perpendicular to the Y direction. Furthermore, the X-Y plane, which includes the X and Y directions, will be described as a plane parallel to the display surface of the display device.

[0017] Unless otherwise explicitly stated, "planar view" refers to a view of a plane parallel to the X-Y plane. Furthermore, the direction normal to the X-Y plane is described as the "Z direction" or thickness direction. The X, Y, and Z directions are intersecting directions. For example, the X, Y, and Z directions are orthogonal directions.

[0018] As shown in Figure 1, the display device DSP1 has a display area DA, a peripheral area PFA, and a plurality of pixels PIX. The peripheral area PFA surrounds the display area DA in a frame-like manner. The plurality of pixels PIX are arranged in a matrix within the display area DA.

[0019] The display device DSP1 also includes a substrate 10, a control circuit 5, and a drive circuit 6. The control circuit 5 and the drive circuit 6 are each formed on the substrate 10.

[0020] The control circuit 5 is a circuit for controlling the display in the display device DSP 1. For example, the control circuit 5 is a driver IC (Integrated Circuit) mounted on the substrate 10. In Figure 1, the control circuit 5 is arranged, for example, along one of the four short sides that make up the outer shape of the substrate 10. The control circuit 5 includes a signal line drive circuit. The signal line drive circuit is a video driver. The signal line drive circuit is a circuit that supplies video signals to video signal lines. The location and configuration examples of the control circuit 5 are not limited to the example shown in Figure 1. For example, in Figure 1, a circuit board such as a flexible substrate may be connected to the location shown as the control circuit 5. In this case, the control circuit 5 is mounted on the circuit board. Also, for example, the signal line drive circuit may be formed separately from the control circuit 5.

[0021] The drive circuit 6 is a scanning driver. The drive circuit 6 is a circuit that supplies scanning signals to the scanning signal line. The drive circuit 6 supplies scanning signals to the scanning signal line based on a control signal from the control circuit 5. The drive circuit 6 is arranged, for example, along each of the two long sides of the four sides that make up the outer shape of the substrate 10. In the example shown in Figure 1, in a plan view, the display area DA is located between the two drive circuits 6. The position and configuration examples of the drive circuit 6 are not limited to the example shown in Figure 1. For example, in Figure 1, a circuit board such as a flexible substrate may be connected to the position shown as the drive circuit 6. In this case, the drive circuit 6 is mounted on the circuit board.

[0022] Next, using Figure 2, we will explain an example of the configuration of a pixel circuit that drives a pixel PIX.

[0023] In Figure 2, a representative pixel circuit is shown to drive one pixel. Each of the multiple pixels PIX shown in Figure 1 is equipped with a circuit similar to the pixel circuit shown in Figure 2. The pixel circuit is a voltage signal type circuit that controls the light emission state of the LED element 20 based on the video signal Vsg supplied from the control circuit 5 (see Figure 1).

[0024] As shown in Figure 2, each pixel PIX is equipped with an LED element 20. The LED element 20 is a light-emitting diode element. The LED element 20 has an anode electrode 20EA and a cathode electrode 20EC.

[0025] The display device DSP1 is equipped with multiple types of wiring in the display area DA. These wirings include multiple scan signal lines GLS, GLR, GLB, multiple video signal lines VL, multiple power lines PL1, multiple power lines PL2, and multiple reset wiring RSL.

[0026] The scan signal lines GLS, GLR, and GLB extend in the X direction. The scan signal lines GLS, GLR, and GLB are connected to the drive circuit 6. For example, as shown in Figure 1, the scan signal lines GLS, GLR, and GLB for driving even-numbered pixels PIX among the pixels PIX arranged in the Y direction are connected to one drive circuit 6. In contrast, the scan signal lines GLS, GLR, and GLB for driving odd-numbered pixels PIX are connected to the other drive circuit 6. As another example, a configuration in which all of the scan signal lines GLS and GLR are connected to one drive circuit 6, and all of the scan signal lines GLB are connected to the other drive circuit 6 is also conceivable. Thus, there are cases in which one of the scan signal lines GLS, GLR, and GLB is connected to one drive circuit 6, and the rest are connected to the other drive circuit 6.

[0027] The video signal line VL, power lines PL1 and PL2, and reset wiring RSL extend in the Y direction. The video signal line VL is connected to the control circuit 5 (see Figure 1). The video signal Vsg and initialization signal are supplied to the video signal line VL from the control circuit 5. High potential Pdvdd is supplied to power line PL1 from the control circuit 5. Low potential Pvss, which is lower than high potential Pdvdd, is supplied to power line PL2 from the control circuit 5. The reset signal Vrs is supplied to the reset wiring RSL from the control circuit 5.

[0028] The control circuit 5 outputs a start pulse signal and a clock signal (not shown) to the drive circuit 6. The drive circuit 6 includes multiple shift register circuits. Based on the clock signal, the drive circuit 6 sequentially transfers the start pulse signal to the next stage shift register circuit. In this way, the drive circuit 6 sequentially supplies scan signals to each scan signal line GLS, GLR, and GLB.

[0029] The pixel circuit controls the LED element 20 based on the video signal Vsg supplied to the video signal line VL. To achieve this control, the pixel circuit includes a reset transistor RST, a pixel selection transistor SST, an output transistor BCT, a drive transistor DRT, a holding capacitor Cs, and an auxiliary capacitor Cad. The auxiliary capacitor Cad is an element provided to adjust the amount of light emitted.

[0030] The reset transistor RST, pixel selection transistor SST, output transistor BCT, and drive transistor DRT are switching elements made of thin-film transistors (TFTs). The conductivity type of the thin-film transistors is not particularly limited. For example, all transistors may be made of N-channel TFTs. However, at least one of the transistors may be made of P-channel TFTs.

[0031] The reset transistor RST, pixel selection transistor SST, output transistor BCT, and drive transistor DRT are formed, for example, using the same process and the same layer structure. These transistors have a bottom gate structure with polycrystalline silicon used for the semiconductor layer. As another example, the reset transistor RST, pixel selection transistor SST, output transistor BCT, and drive transistor DRT may have a top gate structure. For example, oxide semiconductors or polycrystalline GaN semiconductors can be used as the semiconductor layer.

[0032] The reset transistor RST, the pixel selection transistor SST, the output transistor BCT, and the drive transistor DRT each have a source electrode, a drain electrode, and a gate electrode. The gate electrode of each transistor is a control electrode. The source electrode and drain electrode of each transistor can also be simply referred to as electrodes.

[0033] The drive transistor DRT and the output transistor BCT are connected in series with the LED element 20 between power lines PL1 and PL2. The high potential Pvdd supplied to power line PL1 is set to, for example, 10V. The low potential Pvss supplied to power line PL2 is set to, for example, 1.5V.

[0034] The drain electrode of the output transistor BCT is connected to the power line PL1. The source electrode of the output transistor BCT is connected to the drain electrode of the drive transistor DRT. The gate electrode of the output transistor BCT is connected to the scan signal line GLB. The output transistor BCT is turned on / off by the control signal Gsb supplied to the scan signal line GLB. Here, "on" represents a conduction state, and "off" represents a non-conduction state. The output transistor BCT controls the light emission time of the LED element 20 based on the control signal Gsb.

[0035] The source electrode of the drive transistor DRT is connected to one electrode of the LED element 20 (here, the anode electrode 20EA). The other electrode of the LED element 20 (here, the cathode electrode 20EC) is connected to the power line PL2. The drive transistor DRT outputs a drive current to the LED element 20 based on the video signal Vsg.

[0036] The source electrode of the pixel selection transistor SST is connected to the video signal line VL. The drain electrode of the pixel selection transistor SST is connected to the gate electrode of the drive transistor DRT. The gate electrode of the pixel selection transistor SST is connected to the scan signal line GLS. The scan signal line GLS functions as a gate trace for signal writing control. The pixel selection transistor SST is turned on / off by the control signal Gss supplied from the scan signal line GLS. Turning the pixel selection transistor SST on / off switches the connection and disconnection between the pixel circuit and the video signal line VL. That is, by turning on the pixel selection transistor SST, the video signal Vsg or initialization signal from the video signal line VL is supplied to the gate electrode of the drive transistor DRT.

[0037] The source electrode of the reset transistor RST is connected to the reset wiring RSL. The drain electrode of the reset transistor RST is connected to the source electrode of the drive transistor DRT and the anode electrode EA of the LED element 20. The gate electrode of the reset transistor RST is connected to the scan signal line GLR. The scan signal line GLR functions as a gate wiring for reset control. The reset transistor RST is turned on / off by the control signal Grs supplied from the scan signal line GLR. By switching the reset transistor RST on, the potentials of the source electrode of the drive transistor DRT and the anode electrode 20EA of the LED element 20 can be reset. That is, the potentials of the source electrode of the drive transistor DRT and the anode electrode 20EA of the LED element 20 can be reset to the reset signal Vrs supplied to the reset wiring RSL. In other words, the reset wiring RSL is wiring for resetting the voltage of the LED element 20.

[0038] The retaining capacitance Cs is connected between the gate electrode and source electrode of the drive transistor DRT. The auxiliary capacitance Cad is connected between the source electrode of the drive transistor DRT and the power line PL2.

[0039] The drive circuit 6 sequentially supplies scanning signals (control signals Gss, Grs, Gsb) to each scanning signal line GLS, GLR, and GLB. That is, the control signals Gss, Grs, and Gsb are sequentially supplied to the scanning signal lines GLS, GLR, and GLB of each line (a series of pixels PIX arranged in the X direction) based on the start pulse signal and the clock signal. The control circuit 5 also sequentially supplies the video signal Vsg and an initialization signal to each video signal line VL. The charge held in the retaining capacitor Cs when the video signal Vsg is supplied is initialized when the initialization signal is supplied.

[0040] In the configuration described above, the pixel circuits are driven by control signals Gss, Grs, and Gsb supplied to the scan signal lines GLS, GLR, and GLB. Meanwhile, the LED element 20 emits light with a brightness corresponding to the video signal Vsg supplied to the video signal line VL.

[0041] <Basic Idea> The basic idea is to suppress the visibility of the reflection of metal wiring by light by using a black film with low light reflectivity. According to this basic idea, by using a black film with low light reflectivity, the reflection of light during non-lighting can be suppressed. Hereinafter, embodiments embodying the basic idea will be described.

[0042] <Embodiment> <<Configuration of Display Device>> FIG. 3 is a plan view showing the main configuration of the display device 100 in the embodiment.

[0043] In FIG. 3, the display device 100 has a backplane BP, an electrode 111, a bump electrode 113, an LED element 114, a black pattern 130, and a black pattern 140.

[0044] The electrode 111 is surrounded by the black pattern 130 in a plan view. Also, in a plan view, a black pattern 140 is formed on the electrode 111.

[0045] The LED element 114 is disposed on the bump electrode 113. The bump electrode 113 is composed of a black film. [[ID=十四]]

[0046] FIG. 4 is a cross-sectional view of the display device 100 taken along the line A - A in FIG. 3.

[0047] [[ID=十八]] In FIG. 4, the display device 100 has a backplane BP, an LED element 114, an insulating film 117, a contact hole 118, a contact hole 119, and a wiring 120.

[0048] As shown in FIG. 4, the LED element 114 is mounted on the backplane BP. The LED element 114 has an anode electrode 115 formed on the lower surface and a cathode electrode 116 formed on the upper surface located on the opposite side of the lower surface.

[0049] An insulating film 117 is formed on the backplane BP. The insulating film 117 covers the LED element 114. Contact holes 118 and 119 are formed in the insulating film 117. Wiring 120 is formed inside contact hole 118, inside contact hole 119, and on the insulating film 117. The wiring 120 is made of a translucent conductive film. For example, the translucent conductive film is an ITO (Indium Tin Oxide) film. Furthermore, a black pattern 140 is formed inside and on the wiring 120 formed around contact hole 118.

[0050] The backplane BP has a glass substrate 101, a silicon oxide film 102, wiring 103, an organic insulating film 104, contact holes 105, wiring 106, wiring 107, a silicon nitride film 108, contact holes 109, contact holes 110, electrodes 111, electrodes 112, bump electrodes 113, and a black pattern 130.

[0051] In Figure 4, a silicon oxide film 102 is formed on the glass substrate 101. Wiring 103 is formed on the silicon oxide film 102. The wiring 103 is composed of, for example, a "TAT film," which is a laminated film consisting of a titanium film, an aluminum film, and a titanium film in that order from the bottom layer.

[0052] Furthermore, an organic insulating film 104 is formed on the silicon oxide film 102. The organic insulating film 104 is made of, for example, acrylic resin or epoxy resin. The organic insulating film 104 covers the wiring 103.

[0053] A contact hole 105 is formed in the organic insulating film 104. A portion of the wiring 103 is exposed from the bottom of the contact hole 105. Wiring 106 is formed from inside the contact hole 105 across the organic insulating film 104. Wiring 107 is also formed on the organic insulating film 104. At the bottom of the contact hole 105, wiring 106 is connected to wiring 103. Both wiring 106 and wiring 107 are also made of the "TAT film".

[0054] A silicon nitride film 108 is formed on the organic insulating film 104. The silicon nitride film 108 covers the wiring 106 and wiring 107. Contact holes 109 and 110 are formed in the silicon nitride film 108. Part of the wiring 106 is exposed from the bottom of contact hole 109. On the other hand, part of the wiring 107 is exposed from the bottom of contact hole 110.

[0055] Electrodes 111 are formed inside the contact hole 109 and on the silicon nitride film 108. At the bottom of the contact hole 109, the electrodes 111 are connected to the wiring 106. The electrodes 111 are made of, for example, a translucent material such as ITO.

[0056] In contrast, electrodes 112 are formed inside the contact hole 110 and on the silicon nitride film 108. At the bottom of the contact hole 110, the electrodes 112 are connected to the wiring 107. The electrodes 112 are made of, for example, ITO. Bump electrodes 113 are formed on the electrodes 112.

[0057] In this embodiment, the bump electrode 113 is made of a black film. The black film may be made of a black anisotropic conductive film.

[0058] An LED element 114 is positioned on the bump electrode 113. Here, the anode electrode 115 of the LED element 114 is connected to the bump electrode 113. Therefore, the anode electrode 115 is electrically connected to electrode 112 via the bump electrode 113.

[0059] An insulating film 117 is formed on the backplane BP. The insulating film 117 is made of, for example, acrylic resin or epoxy resin. The insulating film 117 covers the LED element 114. Contact holes 118 and 119 are formed in the insulating film 117. A part of the electrode 111 is exposed from the bottom of the contact hole 118. On the other hand, a part of the cathode electrode 116 of the LED element 114 is exposed from the bottom of the contact hole 119.

[0060] Wiring 120 is formed inside the contact hole 118, inside the contact hole 119, and on the insulating film 117. At the bottom of the contact hole 118, the wiring 120 is connected to the electrode 111. Also, at the bottom of the contact hole 119, the wiring 120 is connected to the cathode electrode 116 of the LED element 114. Therefore, the cathode electrode 116 is electrically connected to the electrode 111 via the wiring 120.

[0061] As shown in Figure 4, the backplane BP has wiring 106 that is electrically connected to the electrode 111. The backplane BP also has a black pattern 130 formed above the wiring 106, which overlaps with the wiring 106 in a plan view. For example, the black pattern 130 is positioned lower than the LED element 114. The display device 100 also has a black pattern 140 formed above the electrode 111, which overlaps with the electrode 111 in a plan view. This black pattern 140 is formed on the wiring 120 formed inside and around the contact hole 118. The black pattern 140 is positioned higher than the black pattern 130.

[0062] The display device 100 in this embodiment is configured as described above.

[0063] <<Features of the Embodiment>> The first feature of this embodiment is that, for example, as shown in Figure 4, the bump electrode 113 on which the LED element 114 is mounted is made of a black film. As a result, as shown in Figure 4, for example, by forming the bump electrode 113 from a black film that does not easily reflect light, it is possible to suppress light reflection when the LED element 114 is not lit.

[0064] For example, generally, the bump electrode 113 is made of a metal film with high reflectivity. In this case, when the LED element 114 is not lit, the metal film constituting the bump electrode 113 may reflect light and become visible. In contrast, in this embodiment, the bump electrode 113 is made of a conductive black film. Considering that the light reflectivity of the black film is low, by making the bump electrode 113 from a black film, the reflection of light from the bump electrode 113 when the LED element 114 is not lit can be suppressed.

[0065] On the other hand, since the bump electrode 113 is made of a conductive black film, an electrical connection between the anode electrode 115 and electrode 112 of the LED element 114 can be ensured via the bump electrode 113. In other words, according to this embodiment, the reflection of light from the bump electrode 113 when the LED element 114 is not lit can be suppressed without affecting the electrical connection between the anode electrode 115 and electrode 112.

[0066] For example, a black anisotropic conductive film can be used as a conductive black film. An "anisotropic conductive film" is a film in which conductive particles are dispersed in a resin. When an anisotropic conductive film is heat-pressed, it exhibits conductivity in the direction of pressure (vertical direction) at the pressure-pressed area. In contrast, it exhibits insulating properties in the direction perpendicular to the pressure direction (plane direction). In other words, anisotropic conductive films exhibit "electrical anisotropy". In anisotropic conductive films, conductive paths are formed between electrodes in the pressure direction as the conductive particles are crushed and come into contact. On the other hand, conductive particles that are not crushed remain dispersed in the resin, so insulating properties are maintained between adjacent electrodes in the planar direction.

[0067] Therefore, by using an anisotropic conductive film with black pigment added to the bump electrode 113, it is possible to suppress the reflection of light from the bump electrode 113 when the LED element 114 is not lit, while ensuring the electrical connection between the anode electrode 115 and the electrode 112.

[0068] A second characteristic feature of this embodiment is that, for example, as shown in Figure 4, a black pattern 130 is formed above the wiring 106 and wiring 103 which are electrically connected to the electrode 111. This suppresses the reflection of light from the wiring 106 or wiring 103 when the LED element 114 is not lit.

[0069] Here, from the viewpoint of effectively suppressing light reflection from wiring 106 or wiring 103, it is desirable that the black pattern 130 be located above wiring 106 and wiring 103, and as close to wiring 106 and wiring 103 as possible. For this reason, it is desirable that the black pattern 130 be placed on the silicon nitride film 108 rather than above the insulating film 117. In this case, the black pattern 130 is placed at a lower position than the LED element 114.

[0070] A third characteristic feature of the embodiment is that, for example, as shown in Figure 4, a black pattern 140 is formed above the electrode 111. Specifically, a third characteristic feature of the embodiment is that the black pattern 140 is formed within the contact hole 118 via the wiring 120. This suppresses the reflection of light from the portion of the wiring 106 directly below the electrode 111. In other words, because the electrode 111 is formed, it is difficult to place the black pattern 130 above the portion of the wiring 106 directly below the electrode 111. Furthermore, since the electrode 111 is composed of a light-transmitting electrode, light reflection occurs in the portion of the wiring 106 directly below the electrode 111. In other words, it is difficult for the black pattern 130 to suppress the reflection of light from the portion of the wiring 106 directly below the electrode 111.

[0071] Therefore, in this embodiment, a black pattern 140 is formed above the electrode 111. As a result, reflection of light from the wiring 106 directly below the electrode 111 can be suppressed. In particular, since the contact hole 118 provided in the insulating film 117 reaches the electrode 111, the black pattern 140 is formed inside the contact hole 118. As a result, the black pattern 140 is positioned higher than the black pattern 130.

[0072] From the above, it is desirable to combine the first, second, and third feature points described above in order to effectively suppress light reflection when the LED element 114 is not lit. However, the effect of suppressing light reflection when the LED element 114 is not lit can also be obtained by adopting any of the first, second, or third feature points in the embodiment in the configuration of the display device 100.

[0073] In this embodiment, the black film (black pattern) is not formed in any area other than above the metal wiring. In other words, in this embodiment, the black film (black pattern) is formed only in the minimum necessary area to suppress light reflection when the LED element 114 is not lit.

[0074] Therefore, the technical concept in this embodiment is useful in that it can minimize the reduction in light transmittance caused by the black film (black pattern), even when the display device 100 is applied to a transparent display.

[0075] <<Method of Manufacturing the Display Device>> Next, the method of manufacturing the display device 100 in the embodiment will be described.

[0076] As shown in Figure 5, a backplane BP is prepared. The backplane BP has a glass substrate 101, a silicon oxide film 102, wiring 103, an organic insulating film 104, contact holes 105, wiring 106, wiring 107, a silicon nitride film 108, contact holes 109, contact holes 110, electrodes 111, electrodes 112, bump electrodes 113, and a black pattern 130. In this embodiment, the bump electrode 113 is composed of, for example, a metal film with black pigment added or an anisotropic conductive film with black pigment added. The black pattern 130 is composed of a film with black pigment added and can be formed using patterning techniques including photolithography and etching techniques. The black pattern 130 is formed to surround the electrode 111 and is formed above the wiring 106 and wiring 103 which are electrically connected to the electrode 111. The black pattern 130 is formed to overlap the wiring 106 and wiring 103 in a planar manner.

[0077] Next, as shown in Figure 6, an LED element 114 is placed on the bump electrode 113 of the backplane BP. The LED element 114 has an anode electrode 115 formed on its lower surface and a cathode electrode 116 formed on its upper surface. By placing the LED element 114 on the bump electrode 113, the anode electrode 115 is electrically connected to electrode 112 via the bump electrode 113.

[0078] Subsequently, as shown in Figure 7, an insulating film 117 is applied to the backplane BP. In particular, the insulating film 117 is formed to cover the LED element 114. The insulating film 117 can be made of, for example, acrylic resin or epoxy resin.

[0079] Then, as shown in Figure 8, contact holes 118 and 119 are formed in the insulating film 117 using photolithography and etching techniques. Contact hole 118 reaches electrode 111. On the other hand, contact hole 119 reaches cathode electrode 116 of LED element 114.

[0080] Next, as shown in Figure 9, wiring 120 is formed inside the contact hole 118, inside the contact hole 119, and on the insulating film 117. The wiring 120 is made of a translucent conductive film, which can be formed, for example, by sputtering. The translucent conductive film is, for example, an ITO film. Here, at the bottom of the contact hole 118, the wiring 120 is connected to the electrode 111. Also, at the bottom of the contact hole 119, the wiring 120 is connected to the cathode electrode 116 of the LED element 114. Therefore, the cathode electrode 116 is electrically connected to the electrode 111 via the wiring 120.

[0081] Next, as shown in Figure 4, a film containing black pigment is formed on the wiring 120, and then the film containing black pigment is patterned using photolithography and etching techniques. The patterning is performed so that the film containing black pigment remains inside the contact holes 118, as shown in Figure 4. As a result, a black pattern 140 can be formed inside the contact holes 118. This black pattern 140 is formed above the electrode 111.

[0082] As described above, the display device 100 according to the embodiment can be manufactured.

[0083] The present inventors have described the invention in detail based on its embodiments, but it goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from its essence.

[0084] Within the scope of the concept of the present invention, a person skilled in the art can conceive of various modifications and alterations, and it is understood that such modifications and alterations also fall within the scope of the present invention. For example, any addition, deletion, or design change of components, or addition, omission, or modification of processes, made by a person skilled in the art to the above-described embodiments, is also included within the scope of the present invention, as long as it retains the gist of the present invention.

[0085] Furthermore, any other effects and advantages brought about by the embodiments described herein that are obvious from the description herein or that can be appropriately conceived by a person skilled in the art are naturally considered to be brought about by the present invention.

[0086] 5 Control circuit 6 Drive circuit 10 Substrate 20 LED element 20EA Anode electrode 20EC Cathode electrode BCT Output transistor BP Backplane Cad Auxiliary capacitance Cs Holding capacitance DA Display area DRT Drive transistor DSP1 Display device GLB Scan signal line GLR Scan signal line GLS Scan signal line Grs Control signal line Gsb Control signal line Gss Control signal line PFA Peripheral area PIX Pixel PL1 Power line PL2 Power line Pvdd High potential Pvss Low potential RSL Reset wiring RST Reset transistor SST Pixel selection transistor VL Video signal line Vsg Video signal 100 Display device 101 Glass substrate 102 Silicon oxide film 103 Wiring 104 Organic insulating film 105 Contact hole 106 Wiring 107 Wiring 108 Silicon nitride film 109 Contact hole 110 Contact hole 111 Electrode 112 Electrode 113 Bump electrode 114 LED element 115 Anode electrode 116 Cathode electrode 117 Insulating film 118 Contact hole 119 Contact hole 120 Wiring 130 Black pattern 140 Black pattern

Claims

1. A display device comprising: a backplane having a first electrode and a second electrode; and a light-emitting diode element disposed on the second electrode via a bump electrode, wherein the bump electrode is a black film.

2. The display device according to claim 1, wherein the backplane has metal wiring electrically connected to the first electrode, and the display device has a first black pattern formed above the metal wiring, the first black pattern overlapping the metal wiring in a plan view.

3. In the display device according to claim 1, the black film is a black anisotropic conductive film.

4. In the display device according to claim 1, the first black pattern is positioned lower than the light-emitting diode element.

5. The display device according to claim 2, wherein the display device has a second black pattern formed above the first electrode, the second black pattern overlapping with the first electrode in a plan view.

6. In the display device according to claim 5, the second black pattern is positioned higher than the first black pattern.

7. In the display device according to claim 1, the light-emitting diode element has an upper electrode electrically connected to the first electrode and a lower electrode electrically connected to the second electrode.

8. The display device according to claim 7, wherein the display device has an insulating film formed on the backplane, the insulating film has a contact hole reaching the first electrode, a translucent conductive film is formed inside the contact hole and on the upper surface of the insulating film, the translucent conductive film is connected to the upper electrode, and the upper electrode is electrically connected to the first electrode via the translucent conductive film.

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