Multicolor LED light-emitting structure and preparation method thereof

Abstract

The invention discloses a multicolor LED light-emitting structure and a preparation method thereof, and the preparation method of the multicolor LED light-emitting structure comprises the following steps: providing a substrate and LED chips with different light-emitting colors, enabling the LED chips with different light-emitting colors to be randomly embedded into through holes of different target areas, enabling the LED chips with different light-emitting colors to be embedded into the through holes of the target areas with the same color, and enabling the LED chips with different light-emitting colors to be embedded into the through holes of the target areas with the same color; the LED chips located in the same target area have the same light emitting color, the LED chips located in different target areas have different light emitting colors, and the two electrodes of the LED chips embedded in the through holes are exposed out of the substrate; and preparing a first wiring layer electrically connected with the first electrode and a second wiring layer electrically connected with the second electrode. According to the preparation method of the multi-color LED light-emitting structure, the LED chips do not need to be carried in a point-to-point mode, the production efficiency is greatly improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of light-emitting device manufacturing technology, and in particular to a multi-color LED light-emitting structure and its preparation method. Background Technology

[0002] In the field of display device manufacturing, the key to large-scale commercial production lies in mass transfer technology—that is, how to accurately, efficiently, and stably transfer a massive number of LED chips onto a target substrate. The precision, efficiency, reliability, and yield of the LED chip transfer process directly determine the production cost and market competitiveness of the product.

[0003] Existing technologies typically employ a pick-and-place method, placing each LED chip individually into a predetermined position. When dealing with millions of transfers, this method is inefficient, time-consuming, and requires stringent precision in chip assembly positioning, resulting in high process complexity and manufacturing costs.

[0004] Therefore, it is necessary to improve the existing technology to overcome the aforementioned defects.

[0005] The above content is only used to help understand the technical solution of this application and does not constitute an admission that the above is prior art. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-color LED light-emitting structure and its preparation method, so as to reduce the difficulty of the process.

[0007] To achieve the above-mentioned objectives, in a first aspect, the present invention proposes a method for preparing a multi-color LED light-emitting structure, characterized by comprising the following steps:

[0008] S1. A substrate and LED chips of different emitting colors are provided. The substrate includes a color target area, the color target area includes at least two target areas spaced apart, the target area is provided with a plurality of through holes penetrating the substrate, and the LED chip includes a first electrode and a second electrode located at its two ends respectively.

[0009] S2. The LED chips of different emission colors are randomly embedded in through holes in different target areas. In the same target area, the LED chips located in the same target area have the same emission color, and the LED chips located in different target areas have different emission colors. Both electrodes of the LED chips embedded in the through holes are exposed on the substrate.

[0010] S3. Prepare a first wiring layer electrically connected to the first electrode and a second wiring layer electrically connected to the second electrode.

[0011] Furthermore, in step S2, the step of randomly embedding the LED chips of different emission colors into the through holes of different target areas includes the following steps: placing the LED chip on the substrate, driving the LED chip to move on the substrate, so that the LED chip is embedded into the through hole of the corresponding target area.

[0012] Furthermore, the cross-sectional shapes of the through holes used to carry LED chips of different luminous colors are different, the LED chips are adapted to the through holes, and the LED chips can enter the through holes that are adapted to them, but cannot enter the through holes that are not adapted to them.

[0013] In step S2, when LED chips of different emission colors are randomly embedded into through holes in different target areas, LED chips of different emission colors are placed on the substrate in stages, and the LED chips are driven to move on the substrate so that the LED chips are embedded into the appropriate through holes; or, LED chips of different emission colors are placed on the substrate at the same time, and the LED chips are driven to move on the substrate so that the LED chips are embedded into the appropriate through holes.

[0014] Furthermore, the LED chips are divided into first-color LED chips and second-color LED chips according to their different emission colors, and the color target area includes a first-color target area for carrying the first-color LED chip and a second-color target area for carrying the second-color LED chip;

[0015] In step S2, the step of randomly embedding LED chips of different emitting colors into through holes in different target areas includes:

[0016] Multiple LED chips of the first color are placed on the substrate, and the LED chips are driven to move on the substrate so that the first color LED chips are embedded into the through holes of the first color target area;

[0017] Multiple second-color LED chips are placed on the substrate, and the second-color LED chips are driven to move on the substrate so that the second-color LED chips are embedded in the through holes of the second-color target area.

[0018] Furthermore, the LED chips are divided into first-color LED chips, second-color LED chips, and third-color LED chips according to their different emission colors. The color target area includes a first-color target area for carrying the first-color LED chip, a second-color target area for carrying the second-color LED chip, and a third-color target area for carrying the third-color LED chip.

[0019] In step S2, the step of randomly embedding LED chips of different emitting colors into through holes in different target areas includes:

[0020] Multiple LED chips of the first color are placed on the substrate, and the LED chips are driven to move on the substrate so that the first color LED chips are embedded into the through holes of the first color target area;

[0021] Multiple second-color LED chips are placed on the substrate, and the second-color LED chips are driven to move on the substrate so that the second-color LED chips are embedded into the through holes of the second-color target area;

[0022] Multiple third-color LED chips are placed on the substrate, and the third-color LED chips are driven to move on the substrate so that the third-color LED chips are embedded in the through holes of the third-color target area.

[0023] Furthermore, the through hole has a large end and a small end located at both ends, and the cross-sectional size of the through hole is different in different target areas, and the cross-sectional size of the LED chip with different emitting colors is also different. The LED chip with a smaller cross-sectional size can pass through the through hole with a larger cross-sectional size.

[0024] In step S2, when the LED chips of different colors are randomly embedded into the through holes of different target areas, the larger end of the through hole is kept facing upwards, and the LED chips of different colors are embedded into the corresponding through holes in order from smallest to largest.

[0025] Furthermore, the through hole is a tapered hole;

[0026] The LED chip is adapted to the corresponding through hole;

[0027] The thickness of the LED chip is greater than or equal to the thickness of the through hole;

[0028] The LED chip has a large end and a small end at both ends, and its large end cannot pass through the small end of the through hole, or it cannot pass through both the small end and the large end of the through hole.

[0029] Furthermore, the through hole has a large end and a small end. In step S2, when the LED chips of different emitting colors are randomly embedded into the through holes of different target areas, the large end of the through hole is kept facing upward. The LED chips of different colors are embedded into the through holes of the corresponding target areas in stages. When embedding an LED chip of a certain color, the through hole used to embed LED chips of other colors is blocked.

[0030] Furthermore, the through hole has a large end and a small end, and the cross-sectional dimension of the small end of the LED chip is larger than the cross-sectional dimension of the large end of the second smallest through hole; in step S2, when the LED chips of different emitting colors are randomly embedded into the through holes of different target areas, the large end of the through hole is kept facing upward, the LED chips of different colors are placed on the substrate at the same time, and the LED chips are driven to move on the substrate so that the LED chips are embedded into the through holes of the corresponding target areas.

[0031] Furthermore, in step S2, the LED chip is driven to move on the substrate by driving the substrate to vibrate; or, the LED chip is driven to move on the substrate by airflow, liquid flow, or a pushing component.

[0032] Furthermore, in step S2, after the step of embedding an LED chip of a certain emitting color into the through hole is completed, the following steps are also performed:

[0033] LED chips not embedded in the through holes on the substrate are removed by driving the substrate to vibrate, and / or blowing air, and / or flushing with fluid, and / or pushing with a pusher, and / or tilting the substrate.

[0034] Furthermore, the substrate includes multiple arrayed colored target regions.

[0035] Furthermore, the first wiring layer includes a plurality of first driving lines spaced apart along a second direction and a first insulating layer covering the outside of the first driving lines, the first driving lines extending along a first direction; the second wiring layer includes a plurality of second driving lines spaced apart along the first direction and a second insulating layer covering the outside of the second driving lines, the second driving lines extending along a second direction; the target region corresponds to the overlapping region of the projections of the first driving lines and the second driving lines along the thickness direction of the substrate.

[0036] Further, in step S3, the first wiring layer and the second wiring layer cover the surface of the substrate; or,

[0037] In step S3, before preparing the first wiring layer electrically connected to the first electrode and the second wiring layer electrically connected to the second electrode, the method further includes:

[0038] An encapsulation layer is prepared on the substrate to fix the LED chip.

[0039] The first wiring layer and / or the second wiring layer cover the surface of the encapsulation layer.

[0040] Secondly, this invention proposes a multi-color LED light-emitting structure, comprising:

[0041] The substrate includes a colored target area, the colored target area includes at least two target areas spaced apart, the target area is provided with a plurality of through holes penetrating the substrate, and the LED chip includes a first electrode and a second electrode located at its two ends respectively;

[0042] Multiple LED chips are embedded in the through hole, each including a first electrode at its large end and a second electrode at its small end. Both the first electrode and the second electrode are located outside the through hole. The LED chips in the same target area emit the same color, while the LED chips in different target areas emit different colors.

[0043] The first wiring layer is electrically connected to the first electrode;

[0044] The second wiring layer is electrically connected to the second electrode.

[0045] Furthermore, the first wiring layer and the second wiring layer cover the surface of the substrate; or,

[0046] An encapsulation layer is provided between the first wiring layer and the substrate, and / or between the second wiring layer and the substrate.

[0047] Furthermore, the through hole is a tapered hole, having a large end and a small end located at both ends;

[0048] The LED chip is adapted to the corresponding through hole;

[0049] The thickness of the LED chip is greater than or equal to the thickness of the through hole;

[0050] The LED chip has a large end and a small end at both ends, and its large end cannot pass through the small end of the through hole, or it cannot pass through both the small end and the large end of the through hole.

[0051] Furthermore, the LED chips are divided into first-color LED chips and second-color LED chips according to their different emission colors, and the color target area includes a first-color target area for carrying the first-color LED chips and a second-color target area for carrying the second-color LED chips; or,

[0052] The LED chips are divided into first-color LED chips, second-color LED chips and third-color LED chips according to their different emission colors. The color target area includes a first-color target area for carrying the first-color LED chip, a second-color target area for carrying the second-color LED chip and a third-color target area for carrying the third-color LED chip.

[0053] The cross-sectional dimensions of the vias in the target areas carrying LED chips of different colors are different, and the cross-sectional dimensions of the LED chips of different colors are also different; or, the cross-sectional shapes of the vias in the target areas carrying LED chips of different colors are different, and the cross-sectional shapes of the LED chips of different colors are also different.

[0054] Furthermore, the substrate includes multiple arrayed colored target regions;

[0055] The first wiring layer includes a plurality of first driving lines spaced apart along a second direction and a first insulating layer covering the outside of the first driving lines. The first driving lines extend along a first direction. The second wiring layer includes a plurality of second driving lines spaced apart along the first direction and a second insulating layer covering the outside of the second driving lines. The second driving lines extend along a second direction. The target area corresponds to the overlapping area of ​​the projections of the first driving lines and the second driving lines along the thickness direction of the substrate.

[0056] Furthermore, the LED chips are randomly embedded in the through holes of the target area;

[0057] The target area has at least 10 through holes;

[0058] The LED chip is embedded in one or more through holes in the target area.

[0059] Compared with the prior art, the present invention has the following beneficial effects: According to at least one embodiment of the present invention, the substrate includes a colored target area, the colored target area includes at least two target areas spaced apart, the target area is provided with a plurality of through holes penetrating the substrate, and LED chips of different emitting colors are randomly embedded in the through holes of the corresponding target areas. In the same colored target area, the LED chips located in the same target area emit the same emitting color, and the LED chips located in different target areas emit different emitting colors. By providing a plurality of through holes on the substrate surface, the LED chips can be embedded in the through holes, thereby realizing the positioning of the LED chips on the substrate surface. This is beneficial to ensuring the positional accuracy of the LED chips, and there is no need to transport the LED chips point-to-point, avoiding the high precision requirements of traditional mass transfer, and eliminating the need to use expensive high-precision mass transfer equipment for transfer, which greatly improves production efficiency and reduces production costs. Attached Figure Description

[0060] Figure 1 This is a planar schematic diagram of a substrate according to some embodiments of the present invention, showing the colored target area and the approximate area of ​​the target area.

[0061] Figure 2 This is a planar schematic diagram of the substrate in some embodiments of the present invention.

[0062] Figure 3 This is a cross-sectional schematic diagram of the substrate in some embodiments of the present invention.

[0063] Figure 4 yes Figure 3 The diagram shows an LED chip embedded in a substrate.

[0064] Figure 5 yes Figure 1 The diagram shows a substrate with LED chips randomly embedded in the target area.

[0065] Figure 6 Is Figure 4 The diagram shows a substrate with a first encapsulation layer on its upper surface.

[0066] Figure 7 Is Figure 6 The diagram shows a first wiring layer on the upper surface of the first encapsulation layer.

[0067] Figure 8 Is Figure 7 The diagram shows a substrate with a second encapsulation layer on its lower surface.

[0068] Figure 9 Is Figure 8 The diagram shows a second wiring layer on the lower surface of the second encapsulation layer.

[0069] Figure 10 yes Figure 1 The diagram shows a substrate with LED chips embedded in all through-holes within the target area.

[0070] Figure 11 yes Figure 3 The diagram shows an LED chip embedded in a substrate.

[0071] Figure 12 This is a cross-sectional schematic diagram of a substrate according to some embodiments of the present invention. In the figure, the through-holes in different target areas have different sizes.

[0072] Figure 13 yes Figure 12 The diagram shows a substrate with embedded LED chips.

[0073] Figure 14 yes Figure 13 A comparison diagram of LED chips of different sizes and through holes of different sizes.

[0074] Figure 15 This is a schematic diagram of some embodiments of the present invention when the second-color LED chip and the third-color LED chip are blocked.

[0075] Figure 16 This is a schematic diagram of some embodiments of the present invention when the first color LED chip and the third color LED chip are blocked.

[0076] Figure 17 This is a schematic diagram of some embodiments of the present invention when the first color LED chip and the second color LED chip are blocked.

[0077] Figure 18 This is a schematic diagram of the color target region array distribution in some embodiments of the present invention.

[0078] Figure 19 This is a schematic diagram showing the positions of the first driving line, the second driving line, and the target area in some embodiments of the present invention.

[0079] Figure 20 It is a schematic diagram of the position of the first driving line, the second driving line, and the target area corresponding to a single colored target area.

[0080] Figure 21 This is a cross-sectional schematic diagram of a multi-color LED light-emitting structure according to some embodiments of the present invention. In the figure, the wiring layer covers the surface of the substrate.

[0081] Figure 22 This is a cross-sectional schematic diagram of a multi-color LED light-emitting structure according to some embodiments of the present invention. In the figure, a first encapsulation layer is provided between the first wiring layer and the substrate. Detailed Implementation

[0084] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0085] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0086] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0087] Some embodiments of the present invention provide a method for fabricating an LED light-emitting structure, which includes the following steps:

[0088] S1. Provides a substrate 1 and LED chips 2 with different emitting colors.

[0089] refer to Figure 1 The substrate 1 includes a color target region 12, and the color target region 12 includes at least two target regions 11 spaced apart for carrying LED chips 2 of different emission colors. Figure 1 The boundary of the colored target area 12 is indicated by a double-dotted line, and the boundaries of different target areas 11 are indicated by dashed lines, dotted lines, and solid lines, respectively. It can be understood that the colored target area 12 and target area 11 are artificially defined virtual boundaries; there does not necessarily need to be a clear boundary line on the physical substrate 1 to indicate the corresponding area. Figure 2 As shown, the substrate 1 entity may not have a corresponding boundary line, but of course, a corresponding boundary line can also be manufactured.

[0090] The target area 11 is provided with a plurality of through holes 10 penetrating the substrate 1, specifically, as shown in the example. Figure 3 As shown, substrate 1 has a first surface 1a and a second surface 1b in the thickness direction, and a through hole 10 penetrates the first surface 1a and the second surface 1b of substrate 1. LED chip 2 includes a first electrode 20 and a second electrode 21 located at its two ends, one of which is a positive electrode and the other is a negative electrode. LED chip 2 can be, for example, a vertically structured LED chip. Target area 11 is used to support LED chip 2, and the LED chip 2 supported in each target area 11 emits the same color light, that is, LED chip 2 needs to be placed on the corresponding target area 11.

[0091] S2. LED chips 2 of different emission colors are randomly embedded into the through holes 10 of different target areas 11. In the same colored target area 12, LED chips 2 located in the same target area 11 emit the same emission color, and LED chips 2 located in different target areas 11 emit different emission colors. The state after embedding is shown in [the diagram]. Figure 4 and Figure 5 , Figure 4 and Figure 5In the diagram, the letters R, G, and B on the LED chip 2 represent the light emission colors of the LED chip 2. R, G, and B represent red, green, and blue, respectively. After the LED chip 2 is embedded in the through-hole 10, its first electrode 20 and second electrode 21 are both exposed on the substrate 1. Specifically, the first electrode 20 is exposed on the first surface 1a of the substrate 1, and the second electrode 21 is exposed on the second surface 1b of the substrate 1. The thickness B1 of the LED chip 2 is greater than or equal to the depth H1 of the through-hole 10 (in this embodiment, the depth of the through-hole 10 is consistent with the thickness of the substrate 1) to ensure that the first electrode 20 and the second electrode 21 can be reliably exposed from the substrate 1.

[0092] S3. For example Figure 9 , Figure 21 and Figure 22 As shown, a first wiring layer 4 electrically connected to the first electrode 20 and a second wiring layer 6 electrically connected to the second electrode 21 are prepared.

[0093] The first wiring layer 4 and the second wiring layer 6 are electrically connected to the first electrode 20 and the second electrode 21 of the LED chip 2, respectively, to drive the LED chip 2 to emit light. By driving the LED chips 2 located in different target areas 11 to emit light, different colors of light can be emitted, and more colors can be mixed to achieve color emission. Obviously, since the two electrodes are exposed through the via 10, it is easier to electrically connect them to the first wiring layer 4 and the second wiring layer 6. It can be understood that the color target area 12 does not mean that the area itself is colored, but that the area contains LED chips 2 with different emitting colors. Therefore, the part corresponding to the color target area 12 can subsequently act as a color pixel to emit light of different colors.

[0094] By setting multiple through holes 10 on the surface of the substrate 1, the LED chip 2 can be embedded in the through holes 10, thereby achieving the positioning of the LED chip 2 on the surface of the substrate 1. This helps to ensure the positional accuracy of the LED chip 2, and eliminates the need for point-to-point handling of the LED chip 2, avoiding the high precision requirements of traditional mass transfer. It also eliminates the need for expensive, high-precision mass transfer equipment, greatly improving production efficiency and reducing production costs. It is understandable that one target area 11 can correspond to one monochrome pixel; therefore, it is only necessary to ensure the positional accuracy of the target area 11. Compared to ensuring the positional accuracy of each individual LED chip 2, ensuring the positional accuracy of the target area 11 is easier.

[0095] Furthermore, the LED chip 2 only needs to be randomly embedded in the through-hole 10 of the corresponding target area 11. It is not necessary for every through-hole 10 to contain an LED chip 2. That is, whether or not an LED chip 2 is embedded in a certain through-hole 10 is random. Thus, which through-holes 10 contain LED chips 2 and which do not are also random. It can be understood that as long as there is one through-hole 10 in the target area 11 containing an LED chip 2, that area can emit light normally. Figure 5 This illustrates a possible scenario where LED chips 2 are randomly embedded in the target area 11. Of course, as... Figure 10 As shown, it is also possible that all through holes 10 are embedded with LED chips 2. In this case, the light emission in the target area 11 is more uniform. By repeatedly embedding LED chips 2 into the through holes 10, the fill rate of the through holes can be increased, and the probability that all through holes 10 are equipped with LED chips 2 can be increased.

[0096] Typically, multiple LED chips 2 are embedded within the target area 11. The probability of having only one LED chip 2 is low. Understandably, the number of LED chips 2 embedded within the target area 11 can be increased by increasing the number of vias within the target area 11 or by increasing the probability of LED chips 2 being embedded in the vias 10. Optionally, the target area 11 may have two or more LED chips 2 embedded. Since the target area 100 usually contains a large number of LED chips 2, even if there are damaged LED chips 2, the target area 11 can still emit light normally. This greatly reduces the reliability requirements of the LED chips 2 and increases the process tolerance. For example, in a display screen made with a multi-color LED light-emitting structure, even if there are damaged LED chips 2 in the target area 11, as long as there is at least one normally emitting LED chip 2, the entire screen can display normally, reducing the possibility of dead pixels on the screen.

[0097] Understandably, although the number of LED chips 2 in each target region 11 may differ, this will not affect the luminous brightness of each target region 11. Under constant current source driving conditions, when the forward conduction voltage (Vf) of multiple parallel LED chips is similar, the total current output by the constant current source is approximately evenly distributed among the LED chips. Since the total current is constant, the total luminous power and overall brightness remain unchanged regardless of the number of parallel LED chips. In other words, even if the number of LED chips 2 in each target region 11 is different, as long as each target region 11 is driven by a constant current source, the luminous brightness of each target region 11 can be nearly consistent. Of course, more accurate consistency can be further optimized through algorithms.

[0098] The more LED chips 2 that can emit light within the target area 11, the more uniform the brightness of the pixels corresponding to that target area 11 will be. Optionally, the vias 10 are distributed in an array (e.g., a rectangular array) within the target area 11. This results in a relatively uniform distribution of the vias 10, and when the LED chips 2 are embedded within them, the light in the entire target area 11 becomes even more uniform. In other embodiments, the vias 10 can also be distributed in other forms, such as randomly, to reduce the requirements for the positional accuracy of the vias 10. Furthermore, the number of vias 10 within each target area 11 can be the same or different, greatly reducing the requirements for the positional accuracy of the vias 10 during processing.

[0099] Optionally, the target area 11 has at least 10 through holes 10, so that the target area 11 has a greater possibility of accommodating multiple LED chips 2.

[0100] In some embodiments, step S2, which involves randomly embedding LED chips 2 of different emission colors into the through-holes 10 of different target regions 11, includes the following steps: placing the LED chip 2 on the substrate 1, driving the LED chip 2 to move on the substrate 1, and embedding the LED chip 2 into the through-hole 10 of the corresponding target region 11, thereby facilitating the transfer of the LED chip 2 into the corresponding through-hole 10. For example, LED chips 2 of different emission colors can be placed on the substrate 1 in stages, and driven to move on the substrate 1, so that the LED chip 2 is embedded into the through-hole 10 of the corresponding target region 11. Specifically, multiple LED chips 2 of the same emission color can be placed on the substrate 1 first, and randomly embedded into the through-hole 10 of the corresponding target region 11. Then, multiple LED chips 2 of another emission color can be placed on the substrate 1, and randomly embedded into the through-hole 10 of the corresponding target region 11. This process of embedding different colored LED chips 2 in stages is repeated, and the color of the LED chip 2 is the same each time it is embedded.

[0101] For example, in some examples, LED chips 2 are divided into first-color LED chips 2a, second-color LED chips 2b, and third-color LED chips 2c according to their different emission colors. The emission colors of the first-color LED chips 2a, second-color LED chips 2b, and third-color LED chips 2c are, for example, red, green, and blue, respectively. The color target area 12 includes a first-color target area 11a for carrying the first-color LED chip 2a, a second-color target area 11b for carrying the second-color LED chip 2b, and a third-color target area 11c for carrying the third-color LED chip 2c. In step S2, the step of randomly embedding LED chips 2 of different emission colors into the through holes 10 of different target areas 11 includes:

[0102] Multiple first-color LED chips 2a are placed on the substrate 1, and the first-color LED chips 2a are driven to move on the substrate 1 so that the first-color LED chips 2a are embedded into the through holes 10 of the first-color target area 11a.

[0103] Multiple second-color LED chips 2b are placed on the substrate 1, and the second-color LED chips 2b are driven to move on the substrate 1 so that the second-color LED chips 2b are embedded into the through holes 10 of the second-color target area 11b.

[0104] Multiple third-color LED chips 2c are placed on substrate 1, and the third-color LED chips 2c are driven to move on substrate 1 so that the third-color LED chips 2c are embedded into the through hole 10 of the third-color target area 11c.

[0105] It is understandable that when there are only two different LED chips 2 with different light emission colors, it is only necessary to place the corresponding LED chips on the substrate 1 in two separate steps and drive them to move on the substrate 1 so that they are embedded into the through holes 10 of the corresponding target areas.

[0106] For example, in some examples, LED chips 2 are divided into a first-color LED chip 2a and a second-color LED chip 2b according to their emission colors. The emission colors of the first-color LED chip 2a and the second-color LED chip 2b can be any two of red, green, and blue. The color target area 12 includes a first-color target area 11a for carrying the first-color LED chip 2a and a second-color target area 11b for carrying the second-color LED chip 2b.

[0107] Step S2, which involves randomly embedding LED chips 2 of different emission colors into the through-holes 10 of different target regions 11, includes:

[0108] Multiple first-color LED chips 2a are placed on the substrate 1, and the first-color LED chips 2a are driven to move on the substrate 1 so that the first-color LED chips 2a are embedded into the through holes 10 of the first-color target area 11a.

[0109] Multiple second-color LED chips 2b are placed on the substrate 1, and the second-color LED chips 2b are driven to move on the substrate 1 so that the second-color LED chips 2b are embedded into the through holes 10 of the second-color target area 11b.

[0110] It is understandable that when LED chip 2 has more colors, it is only necessary to add a step of placing the corresponding color LED chip on the substrate and driving it to move on the substrate so that it is embedded in the through hole 10 of the corresponding target area.

[0111] Obviously, when the LED chip 2 moves on the substrate 1, it will be randomly embedded in the through hole 10.

[0112] There are several ways to drive the LED chip 2 to move on the substrate 1.

[0113] In some embodiments, in step S2, the LED chip 2 is driven to move on the substrate 1 by driving the substrate 1 to vibrate, thereby enabling it to be randomly embedded in the through hole 10.

[0114] In other embodiments, multiple LED chips 2 are moved on the substrate 1 by airflow. For example, multiple LED chips 2 can be randomly scattered on the first surface 1a of the substrate 1, and then air is blown onto the surface of the substrate 1 by an air source to move multiple LED chips 2 on the substrate 1. When the LED chip 2 moves to the through hole 10, it can be embedded in the through hole 10.

[0115] In other embodiments, multiple LED chips 2 are moved on the substrate 1 by liquid flow. For example, the LED chips 2 can be placed in a liquid to form an LED paste, which then flows through the substrate 1. The LED chips 2 move under the propulsion of the liquid, and when passing through the through-hole 10, they have a chance of being embedded into it. The liquid carrying the LED chips 2 can be deionized water, an aqueous solution with added surfactants, an organic solvent, or an inert liquid with a density higher than water. It is understood that the liquid does not dissolve or expand encapsulation or adhesive materials, nor does it undergo electrochemical reactions with metals.

[0116] In some embodiments, multiple LED chips 2 are driven to move on the substrate 1 by a pusher. For example, multiple LED chips 2 can be randomly scattered or piled on the first surface 1a of the substrate 1, and then the pusher moves the multiple LED chips 2 so that the LED chips 2 can be embedded in the through holes 10. Optionally, the pusher is flexible to prevent damage to the LED chips 2 and the surface of the substrate 1. Further optionally, the end of the pusher is provided with fine bristles, making the pusher as a whole a fine brush. The movement of the LED chips 2 by the fine bristles can better protect the LED chips 2. By controlling the size and stroke of the pusher, the entire surface of the substrate 1 can be swept in one movement, improving work efficiency.

[0117] Since the precision requirement for LED chip 2 is very low when it is initially placed on substrate 1, and the positioning is completed by moving LED chip 2 to embed it into the through hole 10 with relatively higher precision, the positional requirements of a single LED chip 2 can be greatly reduced when transferring LED chip 2.

[0118] It is understandable that by repeating step S2 multiple times, as many vias 10 as possible can contain LED chips 2, thus increasing the fill rate of vias 10.

[0119] In some embodiments, in step S2, after the step of embedding an LED chip 2 of one color into the through-hole 10 is completed, the following step is also performed: removing LED chips 2 that are not embedded in the through-hole 10. For example, after the step of embedding a first-color LED chip 2a into the through-hole 10 is completed, removing the first-color LED chip 2a that is not embedded in the through-hole 10 is removed to avoid affecting the embedding of LED chips 2 of other colors subsequently. The operation steps for the second-color LED chip 2b and the third-color LED chip 2c are similar.

[0120] There are several ways to remove the LED chip 2 that is not embedded in the through hole 10.

[0121] For example, the LED chip 2 that is not embedded in the through hole 10 can be moved to the edge of the substrate 1 and fall off the edge of the substrate 1 by driving the substrate 1 to vibrate.

[0122] For example, the LED chip 2 that is not embedded in the through hole 10 on the surface of the substrate 1 can be blown away by blowing air.

[0123] For example, the LED chip 2 that is not embedded in the through hole 10 on the surface of the substrate 1 can be removed by fluid flushing.

[0124] For example, the LED chip 2 that is not embedded in the through hole 10 on the surface of the substrate 1 can be swept away by a pusher.

[0125] For example, by tilting the substrate 1, the LED chip 2 that is not embedded in the through hole 10 on the surface of the substrate 1 can roll or slide off under the action of gravity.

[0126] In some embodiments, such as Figure 3 and Figure 4As shown, the through-hole 10 has a large end and a small end located at both ends. For example, the through-hole 10 is a tapered hole, with the cross-sectional dimension of one end being larger than that of the other end. The end with the larger cross-sectional dimension is the large end, and the end with the smaller cross-sectional dimension is the small end. The cross-section refers to the section perpendicular to the axis of the through-hole 10 (which is aligned with the thickness direction of the substrate 1). In the figure, the large end is located on the first surface 1a, and the small end is located on the second surface 1b. The through-hole 10 can be conical (with a circular cross-section) or prismatic (with a polygonal cross-section). Optionally, the LED chip 2 is adapted to the corresponding through-hole 10, and both are contoured to ensure that the LED chip 2 can be reliably embedded within the through-hole 10. For example, when the through-hole 10 is conical, the LED chip 2 is frustum-shaped; when the through-hole 10 is pyramidal, the LED chip 2 is frustum-shaped. Because the LED chip 2 is adapted to the through-hole 10, the LED chip 2 can only be embedded within the through-hole 10 with its smaller end facing down. Obviously, the end of the LED chip 2 with the smaller outer diameter is its small end, and the end with the larger outer diameter is its large end. The LED chip 2 can be entirely contoured to the through-hole 10, or it can be partially contoured to the through-hole 10. For example... Figure 11 In the illustrated embodiment, the middle portion of the LED chip 2 is adapted to the through hole 10, and the two ends are not tapered, but columnar (e.g., cylindrical or prismatic), which facilitates the subsequent filling of encapsulation material between adjacent LED chips 2 to form an encapsulation layer.

[0127] It is understandable that the LED chip 2 does not necessarily need to be contoured to the through hole 10 (for example, the cross-section of the through hole 10 can be circular, and the cross-section of the LED chip 2 can be rectangular). As long as the two ends of the LED chip 2 are different sizes, and the larger end of the LED chip 2 cannot enter the smaller end of the through hole 10, while the smaller end of the LED chip 2 can pass through the smaller end of the through hole 10, the LED chip 2 can be inserted into the through hole 10 with its smaller end facing down. After insertion, the smaller and larger ends of the LED chip 2 can be located outside the through hole 10, respectively. Optionally, the larger end of the LED chip 2 cannot pass through the larger end of the through hole 10 to further ensure that the LED chip 2 is not inserted into the through hole 10 in the opposite orientation. Of course, setting the LED chip 2 and the through hole 10 to be contoured can better ensure the relative positional accuracy of the LED chip 2 and the through hole 10, allowing the LED chip 2 to reliably remain vertical and reducing the risk of the LED chip 2 tilting.

[0128] In some embodiments, the center of gravity of the LED chip 2 is set closer to its small end to make it easier to embed into the through-hole 10 with the small end facing down. For example, the mass of the small end can be increased by adding a counterweight or thickening the second electrode 21. Understandably, the probability of the small end facing down can also be increased in other ways, such as by applying an external magnetic field: depositing a small amount of magnetic metal or attaching unidirectional magnetic particles at the small end, applying a magnetic field below the substrate 1 to orient the LED chip 2. Alternatively, the probability can be increased by applying an external acoustic field or electric field.

[0129] In some embodiments, such as Figure 12 and Figure 13 As shown, the cross-sectional dimensions of the through-holes 10 in different target areas are different, and the cross-sectional dimensions of the LED chips of different emitting colors are also different, so that they can be reliably embedded in the corresponding through-holes 10. The LED chip 2 with a smaller cross-sectional dimension can pass through the through-hole 10 with a larger cross-sectional dimension. Taking the case where the cross-sectional dimensions of the first-color LED chip 2a, the second-color LED chip 2b, and the third-color LED chip 2c increase sequentially as an example, the large-end diameter D5 of the first-color LED chip 2a is smaller than the small-end diameter D6 of the through hole 11 in the second target region 11b, and can pass through the through hole 10 in the second-color target region 11b and the third-color target region 11c. The large-end diameter D7 of the second-color LED chip 2b is smaller than the small-end diameter D8 of the through hole 11 in the third-color target region 11c, and can pass through the through hole 10 in the third-color target region 11c. The large-end diameter D9 of the third-color LED chip 2c is larger than the small-end diameter D6 of the through hole 10 in the second-color target region 11b, and cannot pass through the through hole 10 in the first-color target region 11a and the second-color target region 11b.

[0130] In this case, in step S2, when LED chips 2 of different emitting colors are randomly embedded into the through holes 10 of different target areas 11, the larger end of the through hole 10 is kept facing upward, and the LED chips 2 of different colors are embedded into the corresponding through holes 10 in order from smallest to largest.

[0131] For example, the first-color LED chip 2a, the second-color LED chip 2b, and the third-color LED chip 2c can be sequentially embedded into the through-holes 10 of the corresponding target areas 11. It is understood that when embedding the first-color LED chip 2a, it can fall out of the through-holes 10 of the second-color and third-color target areas 11b and 11c; similarly, when embedding the second-color LED chip 2b, it can fall out of the through-hole 10 of the third-color target area 11c. This prevents the LED chip 2 from being embedded into an incompatible through-hole 10, ensuring the consistency of the emitted color of the LED chip 2 within the target area 11.

[0132] For example, step S2, which involves randomly embedding LED chips 2 of different emission colors into the through holes 10 of different target regions 11, may include the following steps:

[0133] S20. Place multiple first-color LED chips 2a on the substrate 1, drive the first-color LED chips 2a to move on the substrate 1, so that the first-color LED chips 2a are embedded in the through holes 10 of the first-color target area 11a. When the first-color LED chips 2a are embedded in the through holes 10 of other target areas, they will fall below the substrate 1, and remove the first-color LED chips 2a that are not embedded in the through holes 10 of the first-color target area 11a.

[0134] S21. Place multiple second-color LED chips 2b on the substrate 1, drive the second-color LED chips 2b to move on the substrate 1, so that the second-color LED chips 2b are embedded in the through holes 10 of the second-color target area 11b. When the second-color LED chips 2b are embedded in the through holes 10 of the third-color target area 11c, they will fall below the substrate 1, and the second-color LED chips 2b that are not embedded in the through holes 10 of the second-color target area 11b will be removed.

[0135] S22. Place multiple third-color LED chips 2c on the substrate 1, drive the third-color LED chips 2c to move on the substrate 1, so that the third-color LED chips 2c are embedded into the through holes 10 of the third-color target area 11c, and remove the third-color LED chips 2c that are not embedded in the through holes 10 of the third-color target area 11c.

[0136] Obviously, when there are only two colors of LED chips 2, one step can be omitted.

[0137] It is understandable that when the cross-sectional size of the small end of the LED chip 2 is larger than the cross-sectional size of the large end of the second smallest through-hole 10, LED chips 2 of different colors can be embedded in any order. The second smallest through-hole 10 refers to a through-hole whose cross-sectional size is slightly smaller than the through-hole 10 corresponding to the current LED chip 2. For example, Figure 13 In this configuration, the diameter D1 of the small end of the second-color LED chip 2b is larger than the diameter D2 of the large end of the through-hole 10 in the first-color target area 11a, and the diameter D3 of the small end of the third-color LED chip 2c is larger than the diameter D4 of the large end of the through-hole 10 in the second-color target area 11b. Thus, as... Figure 14 As shown, the second-color LED chip 2b can only be embedded in the through hole 10 of the second-color target area 11b, but cannot be embedded in the through hole 10 of the first-color target area 11a. Similarly, the third-color LED chip 2c can only be embedded in the through hole 10 of the third-color target area 11c, but cannot be embedded in the through holes 10 of the first-color target area 11a and the second-color target area 11b.

[0138] Since each color LED chip 2 can only be embedded in a corresponding size through-hole 10, the embedding order is more flexible. For example, the second color LED chip 2b or the third color LED chip 2c can be embedded first, or even two or three different colors of LED chips 2 can be embedded together. Since the smaller LED chip 2 will fall out of the larger through-hole 10, and the larger LED chip 2 will not be embedded in the smaller through-hole 10, the LED chips 2 of different colors can be automatically embedded into the correct corresponding through-holes when they move on the substrate 1.

[0139] In step S2, the step of randomly embedding the LED chips 2 of different emitting colors into the through holes 10 of the corresponding target areas 11 can include the following steps: keeping the large end of the through hole 10 facing upwards, simultaneously placing the LED chips 2 of different colors on the substrate 1, driving the LED chips 2 to move on the substrate 1, so that the LED chips 2 are embedded into the through holes 10 of the corresponding target areas, and then removing the LED chips 2 that are not embedded in the through holes 10. In this way, there is no need to sort the LED chips 2 by color beforehand, or in other words, even if LED chips 2 of different colors are mixed together, it is easy to prepare a multi-color LED light-emitting structure.

[0140] In some embodiments, the cross-sectional shapes of the through holes 10 for carrying LED chips 2 of different emission colors are different. The LED chips 2 are adapted to the through holes 10, and the LED chips 2 can enter the adapted through holes 10 but cannot enter the incompatible through holes 10. In step S2, when LED chips 2 of different emission colors are randomly embedded into the through holes 10 of different target areas 11, the LED chips 2 of different emission colors can be placed on the substrate 1 in stages, and the LED chips 2 can be driven to move on the substrate 1 to embed into the adapted through holes 10. Alternatively, LED chips 2 of different emission colors can be placed on the substrate 1 at the same time, and the LED chips 2 can be driven to move on the substrate 1 to embed into the adapted through holes 10. Similarly, it is not necessary to sort the LED chips 2 by color beforehand.

[0141] In some embodiments, in step S2, when LED chips 2 of different emission colors are randomly embedded into the through holes 10 of different target regions 11, the larger end of the through hole 10 is kept facing upwards. The LED chips 2 of different emission colors are embedded into the through holes 10 of the corresponding target regions 11 in stages. Furthermore, when embedding an LED chip 2 of a certain color, the through holes 10 used for embedding other colors of LED chips 2 are blocked. In this way, even if the LED chips 2 can be embedded into the through holes 10 of different target regions 11 (for example, if the size and shape of the LED chips 2 are consistent, and the size and shape of the through holes 10 of each target region 11 are also consistent), the LED chips 2 will not be embedded into incompatible through holes 10.

[0142] For example, when embedding the first-color LED chip 2a, the through-holes 10 of the second-color target area 11b and the third-color target area 11c can be blocked to prevent the first-color LED chip 2a from being embedded in the through-holes 10 of the second-color target area 11b and the third-color target area 11c. Similarly, when embedding the second-color LED chip 2b, the through-holes 10 of the first-color target area 11a and the third-color target area 11c can be blocked to prevent the second-color LED chip 2b from being embedded in the through-holes 10 of the first-color target area 11a and the third-color target area 11c. Likewise, when embedding the third-color LED chip 2c, the through-holes 10 of the first-color target area 11a and the second-color target area 11b can be blocked to prevent the third-color LED chip 2c from being embedded in the through-holes 10 of the first-color target area 11a and the second-color target area 11b.

[0143] For example, step S2, which involves randomly embedding LED chips 2 of different emission colors into the through holes 10 of different target regions 11, may include the following steps:

[0144] refer to Figure 15 The through holes 10 of the second color target area 11b and the third color target area 11c are blocked (e.g., blocked by the baffle 70). Multiple first color LED chips 2a are placed on the substrate 1, and the first color LED chips 2a are driven to move on the substrate 1 so that the first color LED chips 2a are embedded in the through holes 10 of the first color target area 11a. The first color LED chips 2a that are not embedded in the through holes 10 of the first color target area 11a are removed.

[0145] refer to Figure 16 The through holes 10 of the first color target area 11a and the third color target area 11c are blocked (e.g., by blocking with a baffle 70). Multiple second color LED chips 2b are placed on the substrate 1 and driven to move on the substrate 1 so that the second color LED chips 2b are embedded into the through holes 10 of the second color target area 11b. The second color LED chips 2b that are not embedded in the through holes 10 of the second color target area 11b are removed. Obviously, in this step, the object that previously blocked the second color target area 11b needs to be removed to expose the through holes of the second color target area 11b.

[0146] refer to Figure 17The through holes 10 of the first color target area 11a and the second color target area 11b are blocked (e.g., by blocking with a baffle 70). Multiple third color LED chips 2c are placed on the substrate 1 and driven to move on the substrate 1 so that the third color LED chips 2c are embedded into the through holes 10 of the third color target area 11c. The third color LED chips 2c that are not embedded in the through holes 10 of the third color target area 11c are removed. Obviously, in this step, the object that previously blocked the third color target area 11c needs to be removed to expose the through holes of the third color target area 11c.

[0147] Obviously, when there are only two colors of LED chips 2, one step can be omitted.

[0148] In some embodiments, the substrate 1 includes a plurality of color target regions 12, so that the LED light-emitting structure has multiple color light-emitting regions, enabling it to display more content, for example, it can be made into a display screen. The color target regions 12 may, for example, be distributed in an array. Figure 18 In the diagram, the approximate locations of each colored target region 12 are indicated by double-dotted lines, and the approximate locations of each target region 11 are shown by cross-sectional lines. The colored target regions 12 are distributed in a rectangular array. Clearly, the number and location of the colored target regions 12 can be adjusted according to the number and location of pixels in the display device to be manufactured.

[0149] It is understandable that when the substrate 1 includes multiple colored target areas 12, only the target area 11 corresponding to the LED chip 2 to be embedded can be exposed, while all other target areas are blocked. For example, when embedding the first color LED chip 2a, all the second color target areas 11b and the third color target areas 11c can be blocked.

[0150] In some embodiments, such as Figure 19 As shown, the first wiring layer 4 includes a plurality of first drive lines 41 spaced apart along a second direction, the first drive lines 41 extending along the first direction. The second wiring layer 6 includes second drive lines 61 spaced apart along the first direction, the second drive lines 61 extending along the second direction. Figure 19 In the diagram, the position of the first driving line 41 is indicated by a solid line, and the position of the second driving line 61 is indicated by a dashed line. The first driving line 41 and the second driving line 61 are staggered in the top view direction (i.e., the thickness direction of the substrate 1). Figure 18 and Figure 19As shown, the target region 11 corresponds to the area where the first driving line 41 and the second driving line 61 intersect, that is, the target region 11 corresponds to the overlapping area (i.e., the intersecting area) of the projections of the first driving line 41 and the second driving line 61 along the thickness direction of the substrate 1. Multiple target regions 11 are formed at the intersection of multiple first driving lines 41 and multiple second driving lines 61. Optionally, the first direction and the second direction are perpendicular and both are perpendicular to the thickness direction of the substrate 1.

[0151] like Figure 9 As shown, the upper and lower electrodes of the LED chip 2 in the target area 11 are electrically connected to the first driving line 41 and the second driving line 61, respectively. It can be understood that by applying a positive voltage to the LED chip 2 in the target area 11 through the cooperation of the first driving line 41 and the second driving line 61, independent driving of each target area 11 can be achieved. For example, if the second electrode 21 of the LED chip 2 is the negative electrode and the first electrode 20 is the positive electrode, then a high-level voltage can be applied to the first driving line 41, and the second driving line 61 can be grounded or connected to a low level to drive the LED chip 2 to emit light.

[0152] In a colored target area 12 containing target areas 11, each target area 11 has an independent drive line that can be controlled to be grounded or connected to a low level. All target areas 11 can be connected to another drive line that can be controlled to be connected to a high level voltage (common anode) to independently drive each target area 11 to emit light. Figure 19 In the illustrated embodiment, three second driving lines 61 correspond to three target regions 11, respectively, grounding or connecting the LED chips of the three target regions 11 to a low level. The positive terminals of the LED chips in the three target regions 11 are all connected to the same first driving line 41. Through the three second driving lines 61 and one first driving line 41, the light emission of the three target regions 11 of a colored target region 12 can be independently controlled. It is understood that the target regions 11 within a colored target region 12 can also be common cathode.

[0153] It is understood that in other embodiments, such as Figure 20 As shown, substrate 1 may also include only one colored target area 12, in which case the LED light-emitting structure can be used as a lamp bead.

[0154] LED chip 2 can be a Micro LED chip or a Mini LED chip. Because there is no need for point-to-point mass transfer, the size of LED chip 2 can be made very small, and the cost of a single LED chip 2 is lower. A large number of LED chips 2 can be randomly distributed in a small target area 11. For example, a dozen, dozens, hundreds or even more through holes 10 can be opened to accommodate a large number of LED chips 2, thereby improving the reliability and uniformity of light emission.

[0155] In some embodiments, such as Figure 9 As shown, the first wiring layer 4 further includes a first insulating layer 40 covering the first driving line 41 to better protect the first driving line 41. The second wiring layer 6 further includes a second insulating layer 60 covering the second driving line 61 to better protect the second driving line 61. The first wiring layer 4 and the second wiring layer 6 can be fabricated, for example, using an RDL (Reverse Diode) method.

[0156] In some embodiments, in step S3, the first wiring layer 4 and the second wiring layer 6 cover the surface of the substrate 1, such as... Figure 21 As shown, Figure 21 In this design, the thickness B1 of the LED chip 2 is equal to the thickness H1 of the through-hole 10, and its first electrode 20 and second electrode 21 are flush with the first surface 1a and the second surface 1b of the substrate 1, respectively. It is understood that the thickness B1 of the LED chip 2 can also be greater than the thickness H1 of the through-hole 10, causing the first electrode 20 and the second electrode 21 of the LED chip 2 to protrude to the outside of the substrate 1. Optionally, the substrate 1 has hot-melt properties (similar to hot-melt adhesive), allowing the LED chip 2 embedded in the hole to be bonded and encapsulated by heating, thus fixing the LED chip 2 within the substrate 1 to facilitate the fabrication of the first wiring layer 4 and the second wiring layer 6. For example, the substrate 1 uses a low-temperature non-adhesive material that can be hot-melted after heating to complete the encapsulation, such as ETFE material (ethylene-tetrafluoroethylene copolymer) or silicone film. For example, the substrate 1 can be made of conventional materials (such as glass, silicon wafers, ceramics, or thin films). Then, a liquid hot melt adhesive (such as UV B-Stage adhesive) is coated (e.g., spin-coated) on the surface of the substrate 1 (at least the inner surface of the through hole 10). The adhesive is then "pre-cured" by UV / heating, and the adhesive changes from liquid to solid dry film (extremely thin, for example, less than 1 μm), completely losing its adhesiveness. This makes it easy to insert the LED chip 2 into the through hole 10. The solid dry film can soften and melt again after heating and become adhesive, thus bonding and wrapping the LED chip 2 inside the hole. After cooling, it becomes solid and fixes the LED chip 2.

[0157] In some embodiments, step S3, before preparing the first wiring layer 4 electrically connected to the first electrode 20 and the second wiring layer 6 electrically connected to the second electrode 21, further includes the following step: preparing an encapsulation layer on the substrate 1 to fix the LED chip 2. The encapsulation layer can be formed, for example, by coating with a molding compound, which can fix the LED chip 2 and provide protection. In this case, the first wiring layer 4 and / or the second wiring layer 6 cover the surface of the encapsulation layer. For example, Figure 22In the illustrated embodiment, the thickness B1 of the LED chip 2 is greater than the thickness H1 of the through-hole 10. The first electrode 20 of the LED chip 2 protrudes to the outside of the substrate 1, and the second electrode 21 is flush with the second surface 1b. A first encapsulation layer 3 is formed on the first surface 1a of the substrate 1, a first wiring layer 4 covers the first encapsulation layer 3, and a second wiring layer 6 covers the second surface 1b of the substrate 1. For example, Figure 9 In the illustrated embodiment, the thickness B1 of the LED chip 2 is greater than the thickness H1 of the through hole 10. The first electrode 20 and the second electrode 21 of the LED chip 2 both protrude to the outside of the substrate 1. A first encapsulation layer 3 and a second encapsulation layer 5 are formed on the first surface 1a and the second surface 1b of the substrate 1, respectively. A first wiring layer 4 covers the first encapsulation layer 3, and a second wiring layer 6 covers the second encapsulation layer 5.

[0158] It is understood that when a first encapsulation layer 3 and a second encapsulation layer 5 are present, the first encapsulation layer 3 and the second encapsulation layer 5 can be fabricated in one step or in two separate steps. Optionally, when the first encapsulation layer 3 and the second encapsulation layer 5 are fabricated in two separate steps, step S3 may include the following steps:

[0159] like Figure 6 As shown, a first encapsulation layer 3 is prepared on the first surface 1a of the exposed first electrode 20 on the substrate 1, such as... Figure 7 As shown, a first wiring layer 4 is fabricated on the surface of the first encapsulation layer 3. Figure 8 As shown, a second encapsulation layer 5 is prepared on the second surface 1b of the exposed second electrode 21 on the substrate 1, such as... Figure 9 As shown, a second wiring layer 6 is formed on the surface of the second encapsulation layer 5. It is understood that the process sequence in step S3 is not unique; for example, the first encapsulation layer 3 and the second encapsulation layer 5 can be formed first, followed by the formation of the first wiring layer 4 and the second wiring layer 6. Further optionally, after the first encapsulation layer 3 is formed but before the second encapsulation layer 5 is formed, the following step is included: flipping the substrate 1 so that the second surface 1b of the exposed second electrode 21 of the substrate 1 faces upwards. This allows the operation to always be performed above the substrate 1, which is more convenient and makes it easier to ensure the quality of the process. It is understood that due to the presence of the first encapsulation layer 3, even if the substrate 1 is flipped, the LED chip 2 will not fall out of the through-hole 10.

[0160] It is understood that in some embodiments, the first encapsulation layer 3 and the second encapsulation layer 5 may be two independent encapsulation layers located on two separate surfaces of the substrate 1. In other embodiments, the first encapsulation layer 3 and the second encapsulation layer 5 may also be integral, both covering the entire substrate 1, for example, by potting adhesive onto the outside of the substrate 1 to complete a complete encapsulation of the substrate 1.

[0161] Optionally, when the LED package structure has a package layer, in step S3, before fabricating the first wiring layer 4 on the surface of the first package layer 3, the upper surface of the first package layer 3 is thinned (e.g., by grinding) to expose the first electrode 20 of the LED chip 2. This ensures that the top electrode of the LED chip 2 can be reliably electrically connected to the first driving line 41 during the fabrication of the first wiring layer 4. Similarly, before fabricating the second wiring layer 6 on the surface of the second package layer 5, the outer surface of the second package layer 5 is thinned (e.g., by grinding) to expose the second electrode 21 of the LED chip 2. This ensures that the second electrode 21 of the LED chip 2 can be reliably electrically connected to the second driving line 61 during the fabrication of the second wiring layer 6. It is understood that if the first electrode 20 and the second electrode 21 of the LED chip 2 can be reliably exposed during the fabrication of the package layer, the step of thinning the package layer can be omitted.

[0162] Optionally, the initial thickness (thickness before thinning) of the first electrode 20 and the second electrode 21 is not less than 10 μm, so that after the thinning process, as many or even all of the electrodes of the LED chip 2 as possible can be reliably exposed, ensuring electrical connection with the driving line.

[0163] It is understandable that when the substrate 1 has hot-melt properties (e.g., it is made of hot-melt material or coated with hot-melt adhesive), in step S3, before preparing the first wiring layer 4 electrically connected to the first electrode 20 and the second wiring layer 6 electrically connected to the second electrode 21, the following steps are also included: heating the substrate 1 to bond and encapsulate the LED chip 2 located in the through hole 10, and then cooling the substrate 1 to fix the LED chip 2. After the LED chip 2 is fixed, it may be necessary to continue to set an encapsulation layer, or it may not be set. For example, when the LED chip 2 protrudes significantly from the substrate 1, an encapsulation layer may be set. It is understandable that after the LED chip 2 is fixed by the substrate 1, the LED chip 2 is less likely to shift in position during subsequent processes, which helps to ensure the smooth progress of subsequent processes. It is understandable that when the substrate 1, the first encapsulation layer 3, the second encapsulation layer 5, the first insulating layer 40 and the second insulating layer 60 are all made of transparent materials, and the first driving line 41 and the second driving line 42 are made of transparent materials or have a thin line width, the LED light-emitting structure as a whole is transparent and can be used as a transparent display screen for double-sided display.

[0164] In some embodiments, the substrate 1 is made of glass, silicon wafer, ceramic, or thin film. The thin film is made of an insulating material, such as polyimide (PI, Kapton), polyester film (PET, Mylar, ETFE, silicone film), polycarbonate (PC), or polyethylene terephthalate (PEN).

[0165] This invention also proposes a multi-color LED light-emitting structure, which can be obtained by the preparation method of the multi-color LED light-emitting structure described above.

[0166] In some embodiments, such as Figure 9 As shown, the multi-color LED light-emitting structure includes a substrate 1, multiple LED chips 2, a first wiring layer 4, and a second wiring layer 6. The structure of the multi-color LED light-emitting structure has been described in detail above; the following is a brief description of its main components.

[0167] As described above, the substrate 1 includes a color target region 12, which includes at least two target regions 11 spaced apart, and the target regions 11 are provided with a plurality of through holes 10 penetrating the substrate 1.

[0168] LED chip 2 is embedded in through hole 10. As described above, LED chip 2 is randomly embedded in through hole 10 of target area 11, and target area 11 only needs one LED chip 2 to emit light normally. LED chip 2 is a vertically structured LED chip, with a first electrode 20 and a second electrode 21 at its two ends. In the illustrated embodiment, the larger end of LED chip 2 has the first electrode 20, and the smaller end has the second electrode 21. The thickness B1 of LED chip 2 is greater than or equal to the thickness H1 of through hole 10, and its two ends are exposed at both ends of through hole 10. The LED chip 2 carried in different target areas 11 emits different colors, and the LED chip 2 carried in the same target area 11 emits the same color.

[0169] The first wiring layer 4 is electrically connected to the first electrode 20. As described above, the first wiring layer 4 may include a plurality of first driving lines 41 spaced apart along a second direction and a first insulating layer 40 covering the first driving lines 41. The first driving lines 41 extend along a first direction and are electrically connected to the first electrodes 20 of the LEDs in some target areas 11.

[0170] The second wiring layer 6 is electrically connected to the second electrode 21. As described above, the second wiring layer 6 may include a plurality of second driving lines 61 spaced apart along a first direction and a second insulating layer 60 covering the second driving lines 61. The second driving lines 61 extend along a second direction and are electrically connected to the second electrodes 21 of the LEDs in some target areas 11. The LED chip 2 connected between the first driving line 41 and the second driving line 61 is driven to emit light through cooperation between the first driving line 41 and the second driving line 61.

[0171] In some embodiments, such as Figure 21 As shown, the first wiring layer 4 and the second wiring layer 6 cover the surface of the substrate 1. In other embodiments, an encapsulation layer is provided between the first wiring layer 4 and the substrate 1, and / or between the second wiring layer 6 and the substrate 1, for example, Figure 22A first encapsulation layer 3 is shown to be disposed between the first wiring layer 4 and the substrate 1. Figure 9 The diagram shows a first encapsulation layer 3 and a second encapsulation layer 5 disposed between the first wiring layer 4, the second wiring layer 6, and the substrate 1. The first encapsulation layer 3 is connected to the first surface 1a of the exposed first electrode 20 of the substrate 1, and the second encapsulation layer 5 is connected to the second surface 1b of the exposed second electrode 21 of the substrate 1. The wiring layers cover the corresponding encapsulation layers.

[0172] Optionally, the LED chip 2 is adapted to the through-hole 10, for example, by contouring the two. In some embodiments, the through-hole 10 is tapered, and the LED chip 2 is also tapered. The first electrode 20 is located at its large end, and the second electrode 21 is located at its small end.

[0173] In some embodiments, the LED chip 2 is divided into a first-color LED chip 2a and a second-color LED chip 2b according to the different colors of its emission. The color target area 12 includes a first-color target area 11a for carrying the first-color LED chip 2a and a second-color target area 11b for carrying the second-color LED chip 2b. The through holes 10 of the target areas carrying LED chips of different emission colors have different sizes, and the sizes of LED chips of different emission colors are also different.

[0174] In other embodiments, the LED chips 2 are divided into a first-color LED chip 2a, a second-color LED chip 2b, and a third-color LED chip 2c according to their different emission colors. The color target area 12 includes a first-color target area 11a for carrying the first-color LED chip 2a, a second-color target area 11b for carrying the second-color LED chip 2b, and a third-color target area 11c for carrying the third-color LED chip 2c. The cross-sectional dimensions of the through holes 10 in the target areas carrying LED chips of different emission colors are different, and the cross-sectional dimensions of the LED chips of different emission colors are also different; or, the cross-sectional shapes of the through holes 10 in the target areas carrying LED chips of different emission colors are different, and the cross-sectional shapes of the LED chips of different emission colors are also different.

[0175] It is understood that other embodiments or structural details of the multicolor LED light-emitting structure can be found in the description above in the preparation method of the multicolor LED light-emitting structure, and will not be repeated here.

[0176] It should be noted that, in the absence of conflict, the various embodiments described herein can be combined with each other to obtain more implementation schemes.

[0177] The above are merely specific embodiments of the present invention, and any improvements made based on the concept of the present invention shall be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a multi-color LED light-emitting structure, characterized in that, Includes the following steps: S1. Provide a substrate (1) and LED chips (2) with different light emission colors. The substrate (1) includes a color target area (12). The color target area (12) includes at least two target areas (11) spaced apart. The target area (11) is provided with a plurality of through holes (10) penetrating the substrate (1). The LED chip (2) includes a first electrode (20) and a second electrode (21) located at its two ends respectively. S2. The LED chips (2) of different emission colors are randomly embedded in the through holes (10) of different target areas (11). In the same color target area (12), the LED chips (2) located in the same target area (11) have the same emission color, and the LED chips (2) located in different target areas (11) have different emission colors. The two electrodes of the LED chips (2) embedded in the through holes (10) are exposed on the substrate (1). S3. Prepare a first wiring layer (4) electrically connected to the first electrode (20) and a second wiring layer (6) electrically connected to the second electrode (21).

2. The method for preparing a multi-color LED light-emitting structure as described in claim 1, characterized in that, In step S2, the step of randomly embedding the LED chips (2) of different emission colors into the through holes (10) of different target areas (11) includes the following steps: placing the LED chip (2) on the substrate (1), driving the LED chip (2) to move on the substrate (1), so that the LED chip (2) is embedded into the through hole (10) of the corresponding target area (11).

3. The method for preparing a multicolor LED light-emitting structure as described in claim 1, characterized in that, The cross-sectional shape of the through hole (10) used to carry LED chips (2) of different light emission colors is different. The LED chip (2) is adapted to the through hole (10), and the LED chip (2) can enter the through hole (10) that is adapted to it, but cannot enter the through hole (10) that is not adapted to it. In step S2, when the LED chips (2) of different emitting colors are randomly embedded in the through holes (10) of different target areas (11), the LED chips (2) of different emitting colors are placed on the substrate (1) in stages, and the LED chips (2) are driven to move on the substrate (1) so that the LED chips (2) are embedded into the suitable through holes (10); or, the LED chips (2) of different emitting colors are placed on the substrate (1) at the same time, and the LED chips (2) are driven to move on the substrate (1) so that the LED chips (2) are embedded into the suitable through holes (10).

4. The method for preparing a multi-color LED light-emitting structure as described in claim 1, characterized in that, The LED chip (2) is divided into a first color LED chip (2a) and a second color LED chip (2b) according to the different colors of its light emission. The color target area (12) includes a first color target area (11a) for carrying the first color LED chip (2a) and a second color target area (11b) for carrying the second color LED chip (2b). In step S2, the step of randomly embedding the LED chips (2) of different emission colors into the through holes (10) of different target regions (11) includes: Multiple first-color LED chips (2a) are placed on the substrate (1), and the LED chips (2) are driven to move on the substrate (1) so that the first-color LED chips (2a) are embedded in the through holes (10) of the first-color target area (11a); Multiple second-color LED chips (2b) are placed on the substrate (1), and the second-color LED chips (2b) are driven to move on the substrate (1) so that the second-color LED chips (2b) are embedded in the through hole (10) of the second-color target area (11b).

5. The method for preparing a multicolor LED light-emitting structure as described in claim 1, characterized in that, The LED chip (2) is divided into a first-color LED chip (2a), a second-color LED chip (2b) and a third-color LED chip (2c) according to the different colors of its light emission. The color target area (12) includes a first-color target area (11a) for carrying the first-color LED chip (2a), a second-color target area (11b) for carrying the second-color LED chip (2b) and a third-color target area (11c) for carrying the third-color LED chip (2c). In step S2, the step of randomly embedding the LED chips (2) of different emission colors into the through holes (10) of different target regions (11) includes: Multiple first-color LED chips (2a) are placed on the substrate (1), and the LED chips (2) are driven to move on the substrate (1) so that the first-color LED chips (2a) are embedded in the through holes (10) of the first-color target area (11a); Multiple second-color LED chips (2b) are placed on the substrate (1), and the second-color LED chips (2b) are driven to move on the substrate (1) so that the second-color LED chips (2b) are embedded in the through hole (10) of the second-color target area (11b); Multiple third-color LED chips (2c) are placed on the substrate (1), and the third-color LED chips (2c) are driven to move on the substrate (1) so that the third-color LED chips (2c) are embedded in the through hole (10) of the third-color target area (11c).

6. The method for preparing a multicolor LED light-emitting structure according to any one of claims 1 to 5, characterized in that, The through hole (10) has a large end and a small end at both ends, and the cross-sectional size of the through hole is different in different target areas. The cross-sectional size of the LED chip with different light emission color is also different. The LED chip with a smaller cross-sectional size can pass through the through hole (10) with a larger cross-sectional size. In step S2, when the LED chips (2) of different emitting colors are randomly embedded into the through holes (10) of different target areas (11), the large end of the through hole (10) is kept facing upward, and the LED chips of different colors are embedded into the corresponding through holes in order from small to large.

7. The method for preparing a multicolor LED light-emitting structure as described in claim 6, characterized in that, The through hole (10) is a tapered hole; The LED chip (2) is adapted to the corresponding through hole (10); The thickness of the LED chip (2) is greater than or equal to the thickness of the through hole (10); The LED chip (2) has a large end and a small end at both ends, and its large end cannot pass through the small end of the through hole (10), or it cannot pass through the small end and the large end of the through hole (10).

8. The method for preparing a multicolor LED light-emitting structure according to any one of claims 1 to 5, characterized in that, The through hole (10) has a large end and a small end. In step S2, when the LED chips (2) of different light-emitting colors are randomly embedded into the through holes (10) of different target areas (11), the large end of the through hole is kept facing upward. The LED chips of different colors are embedded into the through holes of the corresponding target areas in turn. When embedding an LED chip of a certain color, the through hole used to embed LED chips of other colors is blocked.

9. The method for preparing a multicolor LED light-emitting structure according to any one of claims 1 to 5, characterized in that, The through hole (10) has a large end and a small end, and the cross-sectional size of the small end of the LED chip (2) is larger than the cross-sectional size of the large end of the second smallest through hole (10); in step S2, when the LED chips (2) of different emitting colors are randomly embedded in the through holes (10) of different target areas (11), the large end of the through hole (10) is kept facing upward, and the LED chips (2) of different colors are placed on the substrate (1) at the same time, and the LED chips (2) are driven to move on the substrate (1) so that the LED chips (2) are embedded in the through holes (10) of the corresponding target areas.

10. The method for preparing a multicolor LED light-emitting structure according to any one of claims 1 to 5, characterized in that, In step S2, the LED chip (2) is driven to move on the substrate (1) by driving the substrate (1) to vibrate; or, the LED chip (2) is driven to move on the substrate (1) by airflow, liquid flow or a pusher.

11. The method for preparing a multicolor LED light-emitting structure according to any one of claims 1 to 5, characterized in that, In step S2, after the step of embedding an LED chip (2) of a certain color into the through hole (10) is completed, the following steps are also performed: LED chips (2) not embedded in the through holes (10) on the substrate (1) are removed by driving the substrate (1) to vibrate, and / or blowing air, and / or flushing with fluid, and / or pushing with a pusher, and / or tilting the substrate (1).

12. The method for preparing a multicolor LED light-emitting structure according to any one of claims 1 to 5, characterized in that, The substrate (1) includes multiple arrayed colored target regions (12).

13. The method for preparing a multicolor LED light-emitting structure according to any one of claims 1 to 5, characterized in that, The first wiring layer (4) includes a plurality of first driving lines (41) spaced apart along a second direction and a first insulating layer (40) covering the outside of the first driving lines (41). The first driving lines (41) extend along a first direction. The second wiring layer (6) includes a plurality of second driving lines (61) spaced apart along a first direction and a second insulating layer (60) covering the outside of the second driving lines (61). The second driving lines (61) extend along a second direction. The target area (11) corresponds to the overlapping area of ​​the projection of the first driving lines (41) and the second driving lines (61) along the thickness direction of the substrate (1).

14. The method for preparing an LED light-emitting structure according to any one of claims 1 to 5, characterized in that, In step S3, the first wiring layer (4) and the second wiring layer (6) cover the surface of the substrate (1); or, In step S3, before preparing the first wiring layer (4) electrically connected to the first electrode (20) and the second wiring layer (6) electrically connected to the second electrode, the following steps are also included: An encapsulation layer is prepared on the substrate (1) to fix the LED chip (2); The first wiring layer (4) and / or the second wiring layer (6) cover the surface of the encapsulation layer.

15. A multi-color LED light-emitting structure, characterized in that, include: The substrate (1) includes a color target area (12), the color target area (12) includes at least two target areas (11) spaced apart, the target area (11) is provided with a plurality of through holes (10) penetrating the substrate (1), and the LED chip (2) includes a first electrode (20) and a second electrode (21) located at its two ends respectively. Multiple LED chips (2) are embedded in the through hole (10), including a first electrode (20) at its large end and a second electrode (21) at its small end. The first electrode (20) and the second electrode (21) are both located outside the through hole (10). The LED chips (2) in the same target area emit the same color, and the LED chips (2) in different target areas emit different colors. The first wiring layer (4) is electrically connected to the first electrode (20); The second wiring layer (6) is electrically connected to the second electrode (21).

16. The LED light-emitting structure as described in claim 13, characterized in that, The first wiring layer (4) and the second wiring layer (6) cover the surface of the substrate (1); or, An encapsulation layer is provided between the first wiring layer (4) and the substrate (1), and / or between the second wiring layer (6) and the substrate (1).

17. The multi-color LED light-emitting structure as described in claim 13, characterized in that, The through hole (10) is a tapered hole with a large end and a small end located at both ends; The LED chip (2) is adapted to the corresponding through hole (10); The thickness of the LED chip (2) is greater than or equal to the thickness of the through hole (10); The LED chip (2) has a large end and a small end at both ends, and its large end cannot pass through the small end of the through hole (10), or it cannot pass through the small end and the large end of the through hole (10).

18. The multi-color LED light-emitting structure as described in claim 15, characterized in that, The LED chip (2) is divided into a first-color LED chip (2a) and a second-color LED chip (2b) according to its emission color. The color target area (12) includes a first-color target area (11a) for carrying the first-color LED chip (2a) and a second-color target area (11b) for carrying the second-color LED chip (2b); or, The LED chip (2) is divided into a first-color LED chip (2a), a second-color LED chip (2b) and a third-color LED chip (2c) according to the different colors of its light emission. The color target area (12) includes a first-color target area (11a) for carrying the first-color LED chip (2a), a second-color target area (11b) for carrying the second-color LED chip (2b) and a third-color target area (11c) for carrying the third-color LED chip (2c). The cross-sectional dimensions of the vias in the target areas carrying LED chips of different colors are different, and the cross-sectional dimensions of the LED chips of different colors are also different; or, the cross-sectional shapes of the vias in the target areas carrying LED chips of different colors are different, and the cross-sectional shapes of the LED chips of different colors are also different.

19. The multicolor LED light-emitting structure according to any one of claims 15 to 18, characterized in that, The substrate (1) includes multiple arrayed colored target regions (12); The first wiring layer (4) includes a plurality of first driving lines (41) spaced apart along a second direction and a first insulating layer (40) covering the outside of the first driving lines (41). The first driving lines (41) extend along a first direction. The second wiring layer (6) includes a plurality of second driving lines (61) spaced apart along a first direction and a second insulating layer (60) covering the outside of the second driving lines (61). The second driving lines (61) extend along a second direction. The target area (11) corresponds to the overlapping area of ​​the projection of the first driving lines (41) and the second driving lines (61) along the thickness direction of the substrate (1).

20. The multicolor LED light-emitting structure according to any one of claims 15 to 18, characterized in that, The LED chip (2) is randomly embedded in the through hole (10) of the target area (11). The target area (11) has at least 10 through holes (10); The LED chip (2) is embedded in one or more through holes (10) of the target area (11).

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