CN109300932B - LED display and manufacturing method thereof - Google Patents

Abstract

The present invention relates to the technical field of displays, and provides an LED display and a manufacturing method thereof. The LED display includes a metal layer and a driving layer that are sequentially superimposed on a substrate. A plurality of micropores are formed in the metal layer. LED chips are embedded in the micropores, and the driving layer includes driving units corresponding to the plurality of micropores. Each driving unit is electrically connected to the LED chip in the corresponding micropore. The LED display is conducive to reducing the difficulty of electrical interconnection between the LED chip and the corresponding driving unit, improving the display resolution, and the integrated metal layer can export the heat emitted by the LED chip during operation, and the metal layer can Effectively isolating the light emitted by LED chips located in adjacent micropores is beneficial to improving the performance of LED displays. The manufacturing method of the LED display is compatible with general semiconductor processes.

Description

LED display and manufacturing method

Technical field

The present invention relates to the field of display technology, and in particular to an LED display and a manufacturing method thereof.

Background technique

LED (Light Emitting Diode) display technology is a display technology that miniaturizes and matrixes traditional LED light sources and uses semiconductor drive circuits to achieve address control and individual driving of each pixel. LED display technology can be used for large-size computer, TV, advertising displays, as well as micro-displays. Because LED displays are self-luminous displays, they have many advantages in terms of brightness, lifespan, contrast, response time, energy consumption, viewing angle and resolution. It has better comprehensive performance and therefore has broad application prospects.

LED displays usually include LED chips distributed in an array (as pixels), a driving array and peripheral circuits used to control the LED chips. The LED chips are attached to the substrate forming the driving array and then communicate with the corresponding driving elements using metal lines. Bonding and other methods are used for electrical interconnection. The current LED display technology still needs improvement in the following aspects: 1. How to improve the electrical interconnection method between the LED chip and the corresponding driving element to improve the resolution; 2. Due to the temperature The increase may lead to a decrease in the luminous efficiency of the LED chip, a drift of the center wavelength, or even failure, so an effective heat dissipation method needs to be provided; 3. Since the light emitted by the LED chip can usually emit through its various surfaces, in order to reduce the size of adjacent pixels Interference between LED chips must be effectively isolated.

Contents of the invention

The object of the present invention is to provide an LED display and a manufacturing method thereof. The LED display can be used for high-resolution display, in which LED chips serving as pixel points are isolated from each other to reduce interference and have better heat dissipation effects.

In one aspect of the invention, an LED display is provided, including:

a base; a metal layer disposed on the base; a plurality of micropores are formed in the metal layer, and an LED chip is embedded in each of the micropores; and a driving layer disposed on the metal layer, so The driving layer includes driving units corresponding to the plurality of microholes, and each driving unit is electrically connected to the LED chip in the corresponding microhole.

Optionally, a peripheral circuit is also provided on the substrate, and the peripheral circuit is electrically connected to the plurality of driving units; the metal layer is connected to a common electrode line in the peripheral circuit.

Optionally, the LED chip includes a first electrode and a second electrode, wherein the first electrode is electrically connected to the corresponding driving unit, and the second electrode is electrically connected to the metal layer.

Optionally, the LED chip is a chip with electrodes on the same plane, and the first electrode and the second electrode are both located on the side of the upper surface of the LED chip away from the substrate, and the corresponding micropores penetrate through them. The metal layer; or, the LED chip is an electrode chip with different surfaces, the first electrode is located on the upper surface side of the LED chip away from the substrate, and the second electrode is located close to the LED chip. On one side of the upper surface of the substrate, the depth of the corresponding micropore is less than the thickness of the metal layer.

Optionally, in a direction perpendicular to the substrate surface, the thickness of the metal layer is 10 μm to 1000 μm.

Optionally, the material of the metal layer includes at least one of stainless steel, copper, nickel, chromium, zinc, and aluminum, or the metal layer includes at least one of iron, copper, nickel, chromium, zinc, and aluminum. An alloy of elements.

Optionally, the LED display further includes an adhesive layer disposed between the upper surface of the substrate and the metal layer to bond the substrate and the metal layer.

Optionally, the material of the adhesive layer includes at least one of polyimide, polyester, and polymethylmethacrylate, or includes iron, nickel, chromium, copper, tin, silver, zinc, copper, At least one type of aluminum.

In another aspect of the present invention, a method for manufacturing an LED display is provided, including the following steps:

A substrate is provided, and a plurality of pixel display areas and a non-display area used to define the multiple pixel display areas are preset on the upper surface of the substrate; a metal layer and a driving layer are formed on the substrate in sequence, and the metal layer Covering the upper surface of the substrate, the driving layer covers the upper surface of the metal layer, and the driving layer includes a plurality of driving units formed corresponding to the non-display area; etching the driving layer and The metal layer is used to form openings penetrating the driving layer corresponding to the plurality of pixel display areas and a plurality of micropores located in the metal layer; embedded in the plurality of micropores one by one. A plurality of LED chips, the LED chip includes a first electrode and a second electrode, the first electrode is located on a surface of the LED chip away from the surface of the substrate; and, planarization is formed on the substrate in sequence layer and an interconnection layer, the planarization layer covers the driving layer and the upper surfaces of the plurality of LED chips, the interconnection layer is located on the planarization layer, the interconnection layer enables each of the The first electrode of the LED chip is electrically connected to the corresponding driving unit.

Optionally, the LED chip is a chip with electrodes on the same plane, the second electrode is located on a surface of the LED chip away from the substrate surface, and the interconnection layer also connects the second electrode with the The metal layer is electrically connected; or, the LED chip is an electrode chip with different surfaces, the second electrode is located on a side of the LED chip close to the upper surface of the substrate, and the depth of the microhole is smaller than that of the metal layer. Thickness, when multiple LED chips are embedded in the multiple micropores one by one, the second electrode contacts and is electrically connected to the metal layer.

In the LED display provided by the present invention, a metal layer and a driving layer are sequentially superimposed on a substrate. A plurality of micropores are formed in the metal layer, and an LED chip is embedded in each of the micropores. The driving layer includes There are drive units corresponding to the plurality of microholes one by one, and each of the drive units is electrically connected to the LED chip in the corresponding microhole. The LED display has the following advantages: First, embedding the LED chip in the microhole in the metal layer is beneficial to limiting the LED chip to a set position. By arranging the electrode of the LED chip in the plane where the driving layer is located, Common film formation, photolithography, etching and other processes can be used to electrically interconnect the LED chip and the driving unit, which will help reduce the difficulty of electrical interconnection between the LED chip and the corresponding driving components, and at the same time help improve the display resolution. ; Secondly, the LED chip is embedded in the micropores in the metal layer. The integrated metal layer has good thermal conductivity, which is conducive to dissipating the heat generated by the LED chip during operation, which is conducive to improving the performance of the LED display; again , because the LED chip is embedded in the microholes in the metal layer, the metal layer can effectively isolate the light emitted by the LED chip in the adjacent pixel display area, which is beneficial to improving the display effect of the LED display.

The manufacturing method of the above-mentioned LED display provided by the present invention sequentially forms a metal layer and a driving layer on a substrate, and then etches to form a plurality of micropores for disposing LED chips in the metal layer. The micropores correspond to the micropores on the upper surface of the substrate. The pixel display area is formed so that the LED chip is used as the pixel point of the LED display, and then multiple LED chips are embedded in the multiple microholes in one-to-one correspondence, and each of the LED chips is connected using the metal interconnection process of the semiconductor planar process. The first electrode of the LED chip is electrically connected to the corresponding driving unit in the driving layer. This manufacturing method is compatible with general semiconductor processes and has the same or similar advantages as the above-mentioned LED displays.

Description of the drawings

FIG. 1 is a schematic flowchart of a method for manufacturing an LED display according to an embodiment of the present invention.

2a to 2e are schematic cross-sectional views of an LED display manufacturing method during implementation according to an embodiment of the present invention.

3a to 3e are schematic cross-sectional views of an LED display manufacturing method during implementation according to another embodiment of the present invention.

Explanation of reference symbols:

1. 2-LED chip;

100, 200-substrate; 101, 201-adhesive layer; 110, 210-metal layer; 120, 220-driving layer; 121, 221-buffer layer; 122, 222-active layer; 124, 224-gate electrode; 126a, 226a-source electrode; 126b, 226b-drain electrode; 123, 223-gate insulating layer; 125, 225-interlayer insulating layer; 127, 227-protective layer; 10, 20-driving unit; 120a, 220a- Opening; 110a, 210a-microhole; 130, 230-planarization layer; 140, 240-interconnection layer; 11-first contact plug; 12-second contact plug; 13-third contact plug; 14 - fourth contact plug; 15 - fifth contact plug; 16 - sixth contact plug.

Detailed ways

The LED display and its manufacturing method of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use imprecise proportions, and are only used to conveniently and clearly assist in explaining the embodiments of the present invention. It will be understood that in the following description, when a layer, region, pattern or structure is referred to as being "on" a base, substrate, layer, region and/or pattern, it can be directly on another layer or substrate. And/or there may also be intervening layers. Similarly, when a layer is referred to as being "under" another layer, it can be directly under the other layer, and/or one or more intervening layers may also be present. In addition, references to "on" and "under" each layer may be made based on the drawings.

The terms "first", "second", etc. in the description and claims are used to distinguish between similar elements and are not necessarily used to describe a specific order or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances, for example to enable the embodiments of the invention described herein to operate in other sequences than described or illustrated herein. Similarly, if a method described herein includes a series of steps, the order of these steps presented herein is not necessarily the only order in which the steps may be performed, and some of the steps described may be omitted and/or some not described herein. Additional steps can be added to the method. If the components of the embodiments of the present invention in the figures are the same as those in other figures, although these components can be easily identified in all the figures, in order to make the description of the embodiments clearer, this specification will not describe all the same components. Labeled with the same number in each figure.

FIG. 1 is a schematic flowchart of a manufacturing method of an LED display according to an embodiment of the present invention. Referring to Figure 1, the manufacturing method of the LED display according to the embodiment of the present invention may include the following steps:

S1: Provide a substrate, the upper surface of which is preset with a plurality of pixel display areas and a non-display area used to define the multiple pixel display areas;

S2: Form a metal layer and a driving layer on the substrate in sequence. The metal layer covers the upper surface of the substrate. The driving layer covers the upper surface of the metal layer. The driving layer includes a layer corresponding to the A plurality of drive units provided in the non-display area;

S3: Etch the driving layer and the metal layer sequentially to form openings penetrating the driving layer corresponding to the plurality of pixel display areas and a plurality of microholes located in the metal layer;

S4: Embed multiple LED chips one by one in the plurality of micropores. The LED chip includes a first electrode and a second electrode. The first electrode is located at a distance away from the substrate surface of the LED chip. side surface;

S5: Form a planarization layer and an interconnection layer sequentially on the substrate. The planarization layer covers the driving layer and the upper surfaces of the plurality of LED chips. The interconnection layer is located above the planarization layer. And in contact with the planarization layer, the interconnection layer electrically connects the first electrode of each LED chip to the corresponding driving unit.

The manufacturing method of the above-mentioned LED display provided by the present invention sequentially forms a metal layer and a driving layer on a substrate, and then etches to form openings penetrating the driving layer and openings located on the driving layer corresponding to multiple pixel display areas in the substrate. A plurality of micropores in the metal layer are embedded with multiple LED chips in a one-to-one correspondence, and an interconnection process is used to connect the first electrode of each LED chip to the corresponding driving unit. Electrical connection. This production method is compatible with general semiconductor processes. In the formed LED display, the LED chip as a pixel is embedded in the microholes in the metal layer, which has the following advantages: First, it is beneficial for the electrodes of the LED chip and the driving layer electrodes to be in the same plane, and facilitates the fixation of the LED chip when it is transferred to the substrate (that is, limiting the LED chip to a set position), which can reduce the difficulty of electrical interconnection between the LED chip and the corresponding drive unit, and at the same time help improve the display resolution. efficiency; secondly, the integrated metal layer has good thermal conductivity, which is beneficial to dissipating the heat emitted by the LED chip during operation, thereby improving the performance of the LED display; thirdly, the metal layer can effectively isolate adjacent pixels in the display The light emitted by the LED chip in the area is also beneficial to improving the display effect of the LED display. The manufacturing method of the above-mentioned LED display and the formed LED display will be described in detail below with reference to two specific embodiments.

Embodiment 1

2a to 2e are schematic cross-sectional views of an LED display manufacturing method during implementation according to an embodiment of the present invention. The manufacturing method of the LED display and the formed LED display according to Embodiment 1 will be described below with reference to FIG. 1 and FIGS. 2a to 2e.

Referring to Figures 1 and 2a, step S1 is first performed to provide a substrate 100, the upper surface of which is preset with a plurality of pixel display areas EA and a non-display area NEA for defining the plurality of pixel display areas EA.

In this embodiment, the substrate 100 is used to provide an LED chip and its driving circuit on one side of its upper surface. The substrate 100 can be a flexible substrate or a rigid substrate. In addition, it can also be a transparent plastic. ) substrate or glass substrate, etc. For example, the substrate 100 may include a transparent glass material whose main component is silicon oxide, or a substrate whose main component is polycarbonate (PC), polyester (PET), cyclic olefin copolymer (COC), or Metal complex substrate-metallocene-based cyclicolefin copolymer (mCOC) and other organic materials, the substrate 100 may not be limited to the listed types. The substrate 100 in this embodiment is, for example, a transparent glass substrate with a thickness of about 0.3 mm to 1.0 mm, in which the plurality of pixel display areas EA may be preset light emitting areas.

Referring to Figures 1 and 2b, step S2 is then performed to sequentially form a metal layer 110 and a driving layer 120 on the substrate 100. The metal layer 110 covers the upper surface of the substrate 100, and the driving layer 120 covers the metal layer. 110 , the driving layer 120 includes a plurality of driving units 10 arranged corresponding to the non-display area NEA.

Specifically, the metal layer 110 can be deposited on the upper surface of the substrate 100 through a process such as physical vapor deposition (PVD), but the present invention is not limited thereto. In this embodiment, considering shortening the film formation time, the metal layer 110 can also be It is a metal foil attached to the upper surface of the substrate 100 . The thickness of the metal layer 110 (or the thickness of the metal foil) is about 10 μm to 1000 μm. The material of the metal layer 110 may include at least one metal selected from stainless steel, copper, nickel, chromium, zinc, and aluminum, or the material of the metal layer 110 It may also include an alloy of at least one element among iron, copper, nickel, chromium, zinc, and aluminum.

The metal foil can be attached to the upper surface of the substrate 100 by bonding or soldering. Referring to Figure 2b, for example, an adhesive layer 101 can be formed on the upper surface of the substrate 100. The material of the adhesive layer 101 can include at least one of polyimide, polyester, and polymethylmethacrylate. The metal foil and the substrate 100 are fixed by adhesion. Alternatively, the adhesive layer 101 can be used as a brazing flux, specifically, it can include at least one metal selected from iron, nickel, chromium, copper, tin, silver, zinc, copper, and aluminum to bond the metal foil to the substrate 100 through a brazing process. fixed. The brazing process is a welding method that uses a brazing flux lower than the melting point of the weldment and the weldment to be simultaneously heated to the melting temperature of the brazing flux, and then uses liquid brazing flux to fill the gaps in the solid workpiece to connect the metals. The specific process of attaching the metal layer 110 using the brazing process can be implemented with reference to the disclosed technology.

The driving layer 120 is formed above the metal layer 110. In this embodiment, the driving layer 120 is a multi-layer structure, which includes a plurality of driving units 10 (located in the dotted frame area in Figure 2b). Each driving unit 10 is used independently or together with Other setting signals of the LED display jointly control the subsequent LED chips set corresponding to the pixel display area EA, that is, the positions of the multiple driving units 10 are formed corresponding to the above-mentioned non-display area NEA. The driving unit 10 may include at least one active component such as a thin film transistor (TFT). In another embodiment of the present invention, the driving unit may include, for example, two thin film transistors and a capacitor (2T1C structure) to better control the turn-off and brightness maintenance characteristics of the corresponding LED chip.

Referring to FIG. 2a, as an example, forming the driving layer 120 may include the following process.

first. A buffer layer 121 is formed on the upper surface of the metal layer 110 to provide a flat surface on the metal layer 110 and provide better interface contact for other materials subsequently deposited. The buffer layer 121 may include an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, aluminum nitride, titanium oxide or titanium nitride and/or an organic material such as polyimide, polyester or acrylic.

Next, the driving unit 10 is formed above the buffer layer 121 using a thin film transistor manufacturing process. The thin film transistor may include an active layer 122, a gate electrode 124, a source electrode 126a and a drain electrode 126b. The thin film transistor shown in FIG. 2a is a top layer. Gate structure, but in other embodiments of the present invention, the thin film transistor can also adopt various types such as bottom gate structure. In the process of forming the thin film transistor, the driving layer 120 may further include a gate insulating layer 123 formed on the active layer 122 for insulating the gate electrode 124 from the active layer 122 , and a gate insulating layer 123 formed on the gate electrode 124 . , an interlayer insulating layer 125 for insulating each of the source electrode 126a and the drain electrode 126b from the gate electrode 124, and the driving layer 120 may further include a protective layer 127 covering the thin film transistor. The formation method of the thin film transistor can also be implemented with reference to the disclosed technology. It should be noted that, within the range of the driving unit corresponding to one pixel display area EA (or one pixel point), more than one thin film transistor can be formed, and it can also be formed in the range of the driving unit through, for example, the overlapping of the above-mentioned functional materials. One or more capacitors are formed inside. Thin film transistors and capacitors can be connected according to a certain functional design and form a driving unit for controlling the operation of pixel points set in the corresponding pixel display area EA. Subsequently, the one-to-one corresponding driving unit and The electrodes of corresponding pixel points are connected to achieve active control of the light-emitting structure of each pixel point.

In addition, in order to control the operation of each pixel of the LED display, during the process of forming the metal layer 110 and the driving layer 120 or before and after the formation, a peripheral circuit can also be formed in the peripheral non-display area on the substrate 100, so as to The electrical signals from the driving unit 10 and the common electrode connected to each pixel point are extracted. In this embodiment, the metal layer 110 may serve as a common electrode of the LED display, and may be electrically connected to the common electrode line in the peripheral circuit.

After the above-mentioned driving layer 120 is formed, refer to FIG. 1 and FIG. 2 c, step S3 is performed, and the driving layer 120 and the metal layer 110 are sequentially etched to form a plurality of penetrating driving layers 120 corresponding to the plurality of pixel display areas EA. The opening 120a and the plurality of micropores 110a located in the metal layer 110.

Specifically, the surface of the driving layer 120 corresponding to the pixel display area EA can be exposed first using a photomask process, and then the exposed surface of the driving layer 120 is etched until the surface of the metal layer 110 corresponding to the pixel display area EA is exposed. An opening 120 a penetrating the driving layer 120 is formed in the driving layer 120 . The process of etching the driving layer 120 can be through one or more dry etching processes, and the dry etching gas can be selected from HBr, Cl ₂ , SF ₆ , O ₂ , N ₂ , NF ₃ , Ar, He, One or more of CHF ₃ , C ₂ F ₆ and CF ₄ gases.

After the surface of the metal layer 110 corresponding to the pixel display area EA is exposed, etching may be performed downward along the exposed surface of the metal layer 110 through, for example, a wet etching process, thereby forming in the metal layer 110 a plurality of There are a plurality of microholes 110a corresponding one-to-one in the pixel display area EA (located below the opening 120a in the driving layer 120 and penetrating the opening 120a). In this embodiment, the back surface of the substrate 100 (the side surface away from the metal layer 110 ) is used as the light-emitting side of the LED display. Therefore, it is preferably etched so that the microholes 110 a penetrate the metal layer 110 . Furthermore, in step S3, the portion of the adhesive layer 101 between the upper surface of the substrate 100 and the metal layer 110 that corresponds to the pixel display area EA may also be etched and removed or not removed.

Referring to Figures 1 and 2d, step S4 is performed to embed a plurality of LED chips 1 in a one-to-one correspondence in the plurality of micropores 110a. The LED chips 1 include a first electrode P and a second electrode N. An electrode P is located on the surface of the LED chip 1 away from the upper surface of the substrate 100. The first electrode P and the second electrode N can be electrode pads formed on the surface of the LED chip 1, after being connected to the corresponding driving circuit. LED chip 1 can emit light. In this embodiment, the LED chip 1 is a chip with electrodes on the same side. Here, "chip with electrodes on the same side" means that the two lead-out electrodes of the LED chip are both arranged on the same side surface of the chip. For example, a formal LED chip can be used Or flip-chip the LED chip as the LED chip 1. In this embodiment, the first electrode P and the second electrode N of the LED chip 1 are located on the side surface of the chip in the same direction. That is, the second electrode N is also located on the LED chip 1. The surface on the side away from the upper surface of the substrate 100. The LED chip 1 can emit light with red (R), green (G), blue (B) colors or light with ultraviolet wavelengths. The LED light with ultraviolet wavelengths can be converted into other colors in the visible light range using fluorescent materials. The LED chip 1 may be a micro-LED. Here, micro-LED may represent an LED with a size of about 1 micron to about 100 microns. However, this embodiment is not limited thereto. In this embodiment, the LED chip 1 may also be a micro-LED with a size smaller than that of a micro-LED. Large or small size LED chips. In other embodiments, according to process and display needs, more than one LED chip can be embedded in the same microhole 110a, and multiple LED chips in the same microhole 110a are electrically connected, and the whole can be passed through A first electrode P and a second electrode N are connected to the external driving circuit.

The LED chip 1 can be embedded in the microhole 110a by bonding. Embedding the LED chip 1 into the microhole 110a can include the following process: dropping an adhesive (not shown) in the microhole 110a, or placing the LED chip 1 in the microhole 110a. One or more surfaces excluding the first electrode P and the second electrode N are coated with adhesive; and then the LED chip 1 is adsorbed on a transfer device. The transfer device can be designed with a one-to-one row corresponding to the micropores 110a. The adsorption component of the cloth is used to transfer multiple adjacent LED chips 1 into the micropores 110a at one time; then the LED chips 1 are transferred to the micropores 110a through the transfer equipment, and the LED chips 1 are adhered to the micropores by the adhesive. In the hole 110a, after curing, the LED chip 1 is fixed in the microhole 110a. In the direction perpendicular to the upper surface of the substrate 100, the thickness of the LED chip 1 is about 10 μm to 140 μm. Preferably, after the LED chip 1 is embedded in the microhole 110a, the upper surface of the LED chip 1 (or the first electrode P, the second electrode The upper surface of N) is not higher than the driving layer 120. More preferably, the thickness of the metal layer 110 and the amount of adhesive can be adjusted according to the size of the LED chip 1 and the area of the pixel display area EA, so that the upper surface of the first electrode P The surface is flush with the source electrode 126a and the drain electrode 126b of the corresponding thin film transistor in the driving unit, and its technical effect is to facilitate electrical interconnection between the first electrode P and the driving unit 10 .

Referring to FIG. 1 and FIG. 2 e, step S5 is then performed to sequentially form a planarization layer 130 and an interconnection layer 140 on the substrate 100. The planarization layer 130 covers the driving layer 120 and the plurality of LED chips 1. On the upper surface, the interconnection layer 140 is located on the planarization layer 130 . The interconnection layer 140 electrically connects the first electrode P of each LED chip 1 to the corresponding driving unit 10 . The planarization layer 130 is used to solve the level difference caused by the driving layer 120, the opening 120a in the driving layer 120, the microhole 110a in the metal layer 110, and the LED chip 1. The planarization layer 130 can also fill the opening 120a, the microhole 110a in the metal layer 110, and the LED chip 1. There may be a gap between the hole 110a and the LED chip 1. The planarization layer 130 may be formed of a single layer or multiple layers of organic materials. The organic material may include polymethyl methacrylate (PMMA) or polystyrene (PS), and the organic material may also include phenolic derivatives, acrylic polymers, imide polymers, and aryl ethers. Polymers, amide polymers, fluorine polymers, p-xylene polymers, vinyl alcohol polymers or their mixtures, etc. The planarization layer 130 may also be formed by stacked inorganic material layers and organic material layers.

The interconnection layer 140 may be electrically connected to the driving unit 10 and the LED chip 1 in the driving layer 120 through the first contact plug 11 and the second contact plug 12 formed in the planarization layer 130, respectively, so that each LED chip The first electrode P of 1 is electrically interconnected with the corresponding driving unit 10 . In this embodiment, the driving unit 10 may include a thin film transistor formed in the driving layer 120. When the drain electrode 126b of the thin film transistor is covered with a protective layer 127, the first contact plug 11 also penetrates the protective layer above the drain electrode 126b. 127. The interconnection layer 140 is also electrically connected to the first electrode P of the LED chip 1 through the second contact plug 12 formed in the planarization layer 130 . The first contact plug 11 and the second contact plug 12 can be formed by first etching to form a contact hole in the planarization layer 130 and then performing, for example, an electroplating process to fill the conductive material. The material of the interconnect layer 140 can be combined with the conductive material in the contact hole. Similarly, the method of forming the first contact plug 11 , the second contact plug 12 and the interconnection layer 140 can be implemented using public technology.

In this embodiment, the LED chip 1 is a horizontal LED chip, and its second electrode N and first electrode P are located on the same direction side of the chip. Furthermore, since the metal layer 110 in this embodiment can be used as a common electrode of the LED display, the above-mentioned interconnection layer 140 can also be electrically connected to the second electrode N of the LED chip 1 through the third contact plug 13 located in the planarization layer 130 , and is electrically connected to the metal layer 110 through the fourth contact plug 14 , where the fourth contact plug 14 penetrates the driving layer 120 below the planarization layer 130 so that the interconnection layer 140 is in contact with the metal layer 110 . That is, the second electrode N of each LED chip 1 forms electrical contact with the metal layer 110, so that the second electrode N forms an electrical interconnection with the common electrode of the LED display to be formed. It should be noted that although the portion of the interconnection layer 140 connected to the first electrode P and the portion of the interconnection layer 140 connected to the second electrode P can be formed through the same film formation process, in order to avoid short circuits, photolithography and patterning can be used. chemical process to disconnect the two.

As shown in Figure 2e, the LED display formed by the above-mentioned LED display forming method in this embodiment includes:

base100;

The metal layer 110 provided on the substrate 100 has a plurality of microholes 110a formed in the metal layer 110, and an LED chip 1 is embedded in each microhole 110a; and

The driving layer 120 is provided on the metal layer 110. The driving layer 120 includes driving units 10 corresponding to the plurality of micropores 110a. Each of the driving units 10 is connected to the corresponding micropores 110a. LED chip 1 is electrically connected.

Furthermore, the LED chip 1 in this embodiment is a lateral LED chip, and the first electrode P and the second electrode N are located on the surface of the LED chip 1 away from the surface of the substrate 100. Correspondingly, on the metal layer 110 The micropores 110a formed in the metal layer 110 penetrate through the metal layer 110 (that is, the etched metal layer 110 has a hollow grid structure). The LED display may further include a peripheral circuit formed on the substrate 100 (for example, formed in a peripheral area of the upper surface of the substrate). The peripheral circuit may be electrically connected to the plurality of driving units 10 , and the metal layer 110 may serve as a The common electrode of the LED display (or connected to the common electrode line in the peripheral circuit). The LED display may further include a planarization layer 130 disposed above the driving layer 120 and an interconnection layer 140 disposed above the planarization layer 130. The first to fourth contact plugs 11 to 130 are disposed in the planarization layer 130. Contact plug 14, interconnection layer 140 electrically connects the first electrode P of LED chip 1 to the corresponding driving unit 10, and electrically connects the second electrode N of LED chip 1 to metal layer 110, thereby realizing LED chip 1 and its Electrical interconnections of drive circuits.

The above-mentioned LED display has the following advantages: first, the LED chip 1 is embedded in the microholes 110a in the metal layer 110 below the driving layer 120, which is beneficial to limiting the LED chip 1 to a set position, and the electrodes of the LED chip 1 Located close to or on a plane where the driving layer 120 is located, the LED chip and the driving unit can be electrically interconnected using common film formation, photolithography, etching and other processes, that is, it can be compatible with semiconductor processes (such as metal interconnection processes) The process avoids the use of electrical connection processes such as wire bonding to electrically interconnect the LED chip 1 and the drive circuit, which is beneficial to reducing the difficulty of electrical interconnection between the LED chip 1 and the corresponding drive unit 10 , and also helps to improve the display resolution; secondly, because the integrated metal layer 110 has good thermal conductivity, the heat generated by the above-mentioned LED display when the LED chip 1 is working is easily exported, which is beneficial to improving the performance of the LED display; Thirdly, the metal layer 110 can effectively isolate the light emitted by the LED chip 1 located in the adjacent microholes, which is beneficial to improving the display effect of the LED display.

Embodiment 2

3a to 3e are schematic cross-sectional views of an LED display manufacturing method during implementation according to another embodiment of the present invention. The manufacturing method of the LED display in Embodiment 2 will be described below with reference to FIG. 1 and FIGS. 3a to 3e.

Referring to Figures 1 and 3a, step S1 is first performed to provide a substrate 200, the upper surface of which is preset with a plurality of pixel display areas EA and a non-display area NEA for defining the plurality of pixel display areas EA. Among them, the substrate 200 can be the same, similar or different from the first embodiment. Specifically, the substrate 200 of this embodiment can also be made of opaque materials such as metal. The LED display subsequently formed starts from the side away from the back of the substrate 200 Emitting light (i.e. top-emitting display).

Referring to Figures 1 and 3b, step S2 is then performed to sequentially form a metal layer 210 and a driving layer 220 on the substrate 200. The metal layer 210 covers the upper surface of the substrate 200, and the driving layer 220 covers the metal layer. 210 , the driving layer 220 includes a plurality of driving units 20 arranged corresponding to the non-display area NEA. The method of forming the metal layer 210 and the driving layer 220 on the substrate 300 in this embodiment can be performed with reference to the process of Embodiment 1. As shown in Figure 3b, the driving layer 220 formed through step S2 may include a buffer layer 221, an active layer 222 of a thin film transistor, and a gate insulating layer 223 (isolating the active layer 222) sequentially formed on the upper surface of the metal layer 210. and the gate electrode 224), the gate electrode 224 of the thin film transistor, and the interlayer insulating layer 225 (isolating the gate electrode 224 from the source electrode 226a and the drain electrode 226b). The source electrode 226a and the drain electrode 226b of the thin film transistor are formed on the interlayer insulating layer 225. The upper surface of the film transistor, and the driving layer 220 may also include a protective layer 227 covering the thin film transistor. In other embodiments, the protective layer 227 may not be formed, but a planarization layer may be used after embedding the LED chip. The source electrode 226a and the drain electrode 226b and the LED chip are covered. In addition, during the process of forming the metal layer 210 and the driving layer 220 or before and after the formation, a peripheral circuit may also be formed in the peripheral non-display area NEA on the substrate 200 to connect the driving unit 20 and the common electrode connected to each pixel point. The electrical signal is derived. In this embodiment, the metal layer 210 can serve as a common electrode of the LED display.

Referring to FIGS. 1 and 3c, step S3 is performed to etch the driving layer 220 and the metal layer 210 in sequence to form a plurality of openings 220a corresponding to the plurality of pixel display areas EA through the driving layer 220 and located in the metal layer 210. a plurality of micropores 210a.

The plurality of openings 220a and the micropores 210a may be formed using the same or similar process as in the embodiment. However, the difference between this embodiment and the first embodiment is that the plurality of micropores 210a formed in the metal layer 210 do not penetrate the metal layer 210, but the depth of the micropores 210a is smaller than the thickness of the metal layer 210, for example Corresponding to the position of the microhole 210a, the metal layer 210 is etched so that it still retains a thickness of about 10 μm to 20 μm. The purpose is to make the electrode of the LED chip embedded in the latter step contact the bottom surface of the microhole 210a to form an electric current. connect.

Referring to Figure 1 and Figure 3d, step S4 is performed to embed multiple LED chips 2 in the multiple microholes 210a one by one. In this embodiment, the LED chip 1 is an electrode chip with different surfaces. Here, "Electrode opposite-side chip" means that the two lead-out electrodes of the LED chip are respectively arranged on the opposite side surfaces of the chip. For example, a vertical LED chip can be used as the LED chip 2 . Since the first electrode P and the second electrode N of the LED chip 2 are respectively located on opposite sides of the chip, the first electrode P is disposed on a surface of the LED chip 2 away from the upper surface of the substrate 200 , then the second electrode N is located on the surface of the LED chip 2 close to the upper surface of the substrate 100 . The LED chip 2 may be a micro LED or an LED larger or smaller in size than the micro LED. In this embodiment, a vertical chip that emits light along the side of the upper surface where the first electrode P is located can be selected as the LED chip 2. It is preferable that the first electrode P occupies a smaller area on the upper surface to facilitate the formation of a better top-emitting light. Characteristic pixels. In other embodiments, according to process and display requirements, more than one LED chip can be embedded in the same microhole 210a, and multiple LED chips in the same microhole 210a are electrically connected, and the whole can be passed through A first electrode P and a second electrode N are connected to the external driving circuit.

The plurality of LED chips 2 can be embedded into the corresponding plurality of microholes 210a through the same or similar process as the method of embedding the LED chips 1 into the microholes 110a in Embodiment 1. In this embodiment, the metal layer 210 can also be used as a common electrode of the LED display to be formed, so that when the LED chip 2 is embedded, the second electrode N can be in direct contact with the bottom surface of the microhole 210a, so that the second electrode N and The common electrode forms electrical interconnections. In order to form a good electrical contact between the second electrode N and the metal layer 210 on the bottom surface of the micropore 210a, the surface of the second electrode N can be coated with, for example, conductive glue to bond with the metal layer 210 on the bottom surface of the micropore 210a. Preferably, after the LED chip 2 is embedded in the microhole 210a, the upper surface of the LED chip 2 (or the upper surface of the first electrode P) is not higher than the driving layer 220. More preferably, it can be based on the size and pixels of the LED chip 2. The area of the display area EA adjusts the thickness of the metal layer 210 and the amount of adhesive so that the upper surface of the first electrode P of the LED chip 2 is flush with the source electrode 226a and drain electrode 226b of the corresponding thin film transistor in the driving unit 20, The technical effect is to facilitate the electrical interconnection of the first electrode P and the corresponding driving unit 20 . However, the present invention is not limited thereto. In other embodiments, the upper surface of the LED chip embedded in the microhole 210a may also be higher than the upper surface of the driving layer 220.

Referring to FIG. 1 and FIG. 3 e, step S5 is then performed to sequentially form a planarization layer 230 and an interconnection layer 240 on the substrate 200. The planarization layer 230 covers the driving layer 220 and the plurality of LED chips 2. On the upper surface, the interconnection layer 240 is located on the planarization layer 230 . The interconnection layer 240 electrically connects the first electrode P of each LED chip 2 to the corresponding driving unit 20 . The planarization layer 230 and the interconnection layer 240 in this embodiment can be formed using the same or similar materials and methods as in Embodiment 1. The planarization layer 230 is preferably a material with better light transmittance to facilitate the LED display to be formed. The middle LED chip 2 emits light along the side facing the planarization layer 230 . The planarization layer 230 is used to solve the level difference caused by the driving layer 220, the opening 220a in the driving layer 220, the microhole 210a in the metal layer 210, and the LED chip 2, and can also fill the opening 220a, the microhole 210a and the LED chip 2. Possible gaps between LED chips 2. The interconnection layer 240 is used to electrically interconnect the first electrode P of each LED chip 2 with the corresponding driving unit 20 . Specifically, the interconnection layer 240 can be through a fifth contact plug formed in the planarization layer 230 15 is electrically connected to the driving unit 20 (specifically, a thin film transistor therein) in the driving layer 220 , so that the first electrode P of each LED chip 1 is electrically interconnected with the corresponding driving unit 10 . In this embodiment, the driving unit 20 may include a thin film transistor formed in the driving layer 120. When the drain electrode 226b of the thin film transistor is covered with a protective layer 227, the fifth contact plug 15 also penetrates the protective layer above the drain electrode 226b. 227. The interconnection layer 240 is also electrically connected to the first electrode P of the LED chip 2 through the sixth contact plug 16 formed in the planarization layer 230 . Since the LED chip 2 in this embodiment is a vertical LED chip, its first electrode P and second electrode N can be electrically connected to the driving unit 20 in the driving layer 220 and the metal layer 210 (as a common electrode) below the driving layer 220 respectively. For connection, the driving unit 20 and the metal layer 210 can be designed to be connected to a peripheral circuit formed on the substrate 200, so that the turn-off and other display characteristics of the LED chip 2 can be controlled by an external power supply and driver.

As shown in Figure 3e, the LED display formed by the above-mentioned LED display forming method in this embodiment includes:

Base 200;

The metal layer 210 is provided on the substrate 200. A plurality of microholes 210a are formed in the metal layer 210, and the LED chip 2 is embedded in each of the microholes 210a; and

The driving layer 220 is disposed on the metal layer 210. The driving layer 220 includes driving units 20 corresponding to the plurality of micropores 210a. Each of the driving units 20 is connected to the corresponding micropores 210a. LED chip 2 is electrically connected.

Furthermore, the LED chip 2 in this embodiment is an electrode chip with different surfaces, and the first electrode P and the second electrode N are respectively located on the surface of the LED chip 2 away from the upper surface of the substrate 100 and close to the upper surface of the substrate 100 On one side of the surface, correspondingly, in the direction perpendicular to the upper surface of the substrate 100 , the depth of the micropores 210 a is smaller than the thickness of the metal layer 210 . The LED display may further include a peripheral circuit formed on the substrate 100 (for example, formed in a peripheral area of the upper surface of the substrate). The peripheral circuit may be electrically connected to the plurality of driving units 20 , and the metal layer 210 may serve as a The common electrode of the LED display (or connected to the common electrode line in the peripheral circuit), and the second electrode N of the LED chip 2 is formed with the common electrode of the LED display by contacting the surface of the metal layer 210 in the microhole 210a Electrical interconnections. The LED display may further include a planarization layer 230 disposed above the driving layer 220 and an interconnection layer 240 disposed above the planarization layer 230, through the fifth contact plug 15 and the sixth contact plug 15 disposed in the planarization layer 230. Contact plug 16 , interconnection layer 240 electrically connects first electrode P to the corresponding driving unit 20 .

The above-mentioned LED display has the following advantages: first, the LED chip 2 is embedded in the microhole 210a in the metal layer 210 below the driving layer 220, which is beneficial to limiting the LED chip 1 to a set position, and the electrodes of the LED chip 2 are Located close to or on a plane where the driving layer 220 is located, general film formation, photolithography, etching and other processes can be used to electrically interconnect the LED chip and the driving unit, thereby reducing the cost between the LED chip 2 and the corresponding driving unit 20 The difficulty of electrical interconnection is also conducive to improving the display resolution; secondly, the integrated metal layer 210 has good thermal conductivity, which is conducive to dissipating the heat emitted by the LED chip 2 during operation, which is conducive to improving the performance of the LED display ; Thirdly, the metal layer 210 can effectively isolate the light emitted by the LED chip 2 located in the adjacent microholes 210a, which is beneficial to improving the display effect of the LED display.

The LED display of the present invention is not limited to the manufacturing method described in the above embodiment. In other embodiments, in order to form the LED display of the present invention, the metal layer can also be bonded (or deposited) on the substrate, and then the metal layer can be first Etching is performed to form a microhole array, and then the corresponding LED chip (such as a lateral chip) is embedded in the microhole, and then a driver layer covering the metal layer and the LED chip is formed, and the driver unit in the driver layer is connected to the driver in the microhole. The LED chip is electrically connected; this method can eliminate the step of etching the driving layer to form an opening corresponding to the pixel display area, such as when the LED display is a bottom-emitting display (for example, when the substrate is a transparent substrate and the microholes penetrate the metal layer), The driving unit can also be arranged in the area directly above the microhole, which is beneficial to increasing the aperture ratio of the pixels and improving the display resolution.

It should be noted that each embodiment in this specification is described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. .

The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of rights of the present invention. Any person skilled in the art can use the methods and technical contents disclosed above to improve the present invention without departing from the spirit and scope of the present invention. Possible changes and modifications are made to the technical solution. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention, all belong to the technical solution of the present invention. protected range.

Claims (9)

1. An LED display, characterized in that it includes: base; A metal layer disposed on the substrate, a plurality of micropores formed in the metal layer, and an LED chip embedded in each of the micropores; and A driving layer provided on the metal layer, the driving layer includes driving units corresponding to the plurality of micropores, each of the driving units is electrically connected to the LED chip in the corresponding microhole; The LED chip includes a first electrode and a second electrode, wherein the first electrode is electrically connected to the corresponding driving unit, and the second electrode is electrically connected to the metal layer. 2. The LED display of claim 1, wherein a peripheral circuit is further provided on the substrate, and the peripheral circuit is electrically connected to the plurality of driving units; the metal layer and the peripheral circuit are electrically connected to each other. common electrode line connection. 3. The LED display of claim 1, wherein the LED chip is a chip with electrodes on the same plane, and the first electrode and the second electrode are both located on the upper surface of the LED chip away from the substrate. On one side of the surface, the corresponding micropores penetrate the metal layer; or, the LED chip is a chip with electrodes on opposite sides, and the first electrode is located on the upper surface side of the LED chip away from the substrate, so The second electrode is located on a side of the LED chip close to the upper surface of the substrate, and the depth of the corresponding microhole is less than the thickness of the metal layer. 4. The LED display according to any one of claims 1 to 3, characterized in that, in a direction perpendicular to the substrate surface, the thickness of the metal layer is 10 μm to 1000 μm. 5. The LED display according to any one of claims 1 to 3, wherein the material of the metal layer includes at least one metal selected from stainless steel, copper, nickel, chromium, zinc, and aluminum, or, the The metal layer includes an alloy of at least one element selected from iron, copper, nickel, chromium, zinc, and aluminum. 6. The LED display according to any one of claims 1 to 3, characterized in that the metal layer is a metal foil, and the LED display further includes a device disposed between the upper surface of the substrate and the metal foil. An adhesive layer to join the substrate and the metal foil. 7. The LED display of claim 6, wherein the material of the adhesive layer includes at least one of polyimide, polyester, and polymethylmethacrylate, or includes iron, nickel, At least one of chromium, copper, tin, silver, zinc, copper and aluminum. 8. A method of manufacturing an LED display, characterized by comprising: Provide a substrate, the upper surface of which is preset with a plurality of pixel display areas and a non-display area for defining the plurality of pixel display areas; A metal layer and a driving layer are formed on the substrate in sequence, the metal layer covers the upper surface of the substrate, the driving layer covers the upper surface of the metal layer, the driving layer includes a Multiple driving units formed by the display area; Etching the driving layer and the metal layer sequentially to form openings penetrating the driving layer corresponding to the plurality of pixel display areas and a plurality of microholes located in the metal layer; A plurality of LED chips are embedded in the plurality of micropores in a one-to-one correspondence. The LED chip includes a first electrode and a second electrode. The first electrode is located on a side of the LED chip away from the surface of the substrate. surface, the second electrode is used to electrically connect with the metal layer; and, A planarization layer and an interconnection layer are sequentially formed on the substrate. The planarization layer covers the driving layer and the upper surfaces of the plurality of LED chips. The interconnection layer is located on the planarization layer. The interconnection layer electrically connects the first electrode of each LED chip to the corresponding driving unit. 9. The method of manufacturing an LED display according to claim 8, wherein the LED chip is a chip with electrodes on the same plane, and the second electrode is located on a surface of the LED chip away from the surface of the substrate, The interconnection layer also electrically connects the second electrode to the metal layer; alternatively, the LED chip is a chip with electrodes on opposite sides, and the second electrode is located on the upper surface of the LED chip close to the substrate. On one side, the depth of the microholes is less than the thickness of the metal layer. When multiple LED chips are embedded in the multiple micropores one by one, the second electrode contacts and is electrically connected to the metal layer. .