LED array device based on LEDs of vertical structure

Abstract

The utility model relates to an LED array device based on vertical structure LEDs, which comprises a driving bottom plate, a flexible film and a plurality of vertical structure LEDs, the flexible film is arranged on the outer side of the driving bottom plate, a first electrode is arranged on the outer side surface of the driving bottom plate, a second electrode is arranged on the inner side surface of the flexible film, and the second electrode and the first electrode are oppositely arranged and form an electrode overlapping area; a third electrode and a fourth electrode are respectively arranged on the inner side surface and the outer side surface of the LED with the vertical structure, and the third electrode is conductively connected with the first electrode; the flexible film and the driving bottom plate are bonded through a sealing rubber ring and define a negative pressure cavity. Each LED with the vertical structure is positioned in the negative pressure cavity; the flexible film is tightly attached to the LEDs of the vertical structures under the negative pressure of the negative pressure cavity, so that the fourth electrodes and the second electrodes are in conductive connection. According to the LED array device, the manufacturing process can be simplified, the flexible film can be tightly attached to the LED of the vertical structure easily, and it is guaranteed that pressure is kept between the fourth electrode and the second electrode.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor display, in particular to an LED array device based on vertical structure LEDs. Background Art

[0002] LED array devices use LEDs as array units for controllable light emission, which can be directly used as displays or as dynamic backlights for liquid crystal displays to achieve high brightness and high contrast display effects. Vertical structure LEDs are LEDs with two electrodes (P pole and N pole) respectively arranged on the two sides of the LED. LED array devices generally arrange a large number of LEDs on the driving substrate according to the array. In LED array devices, vertical structure LEDs are used, and LEDs do not need to be arranged at a specific angle, which can greatly reduce their manufacturing difficulty. However, one electrode of the vertical structure LED forms a conductive connection at the bottom with the circuit (such as a pad) on the driving substrate, while the other electrode is at the top. It is necessary to construct a line across to the top of the LED (including a transparent electrode) to form a complete driving circuit. However, due to the large thickness of the vertical structure LED (2 to 200 μm), coupled with the uneven top caused by welding and binding, it is generally difficult to construct a line across to the top of the LED.

[0003] In the prior art, after the vertical structure LED is set on the driving base plate, a certain flattening layer (such as a flat paint layer) is generally required to be set, and then the top circuit is formed on the flattening layer by coating, photolithography and other technologies, and a hole is also required in the flattening layer to facilitate the top circuit to form a circuit connection with the driving base plate, so its manufacturing process is very complicated, and because of its uneven top, the pattern accuracy of its top circuit is very low, so it is difficult to make a more complex circuit pattern. In addition, there is a seam between the flattening layer and the vertical structure LED, and stress and strain are easily concentrated at the seam position, causing the top circuit to break. Therefore, the bending resistance of this LED array device is also very poor, and due to the protrusion of the vertical structure LED, its top circuit is also easily damaged when it is hit or rubbed by foreign objects. Therefore, the top circuit of the LED array device with this structure is not only difficult to process, but also very prone to failure during production, transportation, and use, and has poor reliability.

[0004] In order to solve the above problems, the applicant submitted an application on April 13, 2024 and was authorized for a Chinese invention patent with a publication number of "CN118156256A" and a patent name of "A LED array device and its manufacturing method". The LED array device disclosed therein includes a driving base plate 1, a flexible film 2 and a plurality of vertical structure LEDs 3. A first electrode 10 is provided on the outer surface of the driving base plate 1; the flexible film 2 is bonded to the outer surface of the driving base plate 1, and a light-transmitting second electrode 20 is provided on the inner side of the flexible film 2. The second electrode 20 and the first electrode 1 0 are arranged opposite to each other and have a plurality of electrode overlapping areas 100; the LED array device has a plurality of array units 50 constituting an array, the electrode overlapping areas 100 correspond to the array units 50, each electrode overlapping area 100 is provided with a vertical structure LED 3, the vertical structure LED 3 is sandwiched between the driving base plate 1 and the flexible film 2, the inner side of the vertical structure LED 3 is provided with a third electrode 30, the third electrode 30 and the first electrode 10 form a conductive structure; the outer side of the vertical structure LED 3 is provided with a fourth electrode 31, the fourth electrode 31 and the second electrode 20 form a conductive structure. This LED array device can reduce the design difficulty of the LED circuit and produce a more complex circuit pattern on the top circuit. In order to ensure good conductivity between the second electrode and the fourth electrode, the vertical structure LED needs to be pressed by the flexible film 2. The manufacturing method adopted is: firstly, an adhesive 300 is set on the outer surface of the driving base plate, and then the flexible film 2 is pressed onto the driving base plate 1, so that the flexible film 2 is bonded to the driving base plate 1 through the adhesive 300, and pressure is applied to make the flexible film 2 pressed by the vertical structure LED 3, and the adhesive 300 is solidified while maintaining the pressure; finally, the pressure is removed, and the flexible film 2 maintains its pressed state against the vertical structure LED 3 under the adhesive force of the adhesive 300, thereby making the flexible film 2 stretched on the top of each vertical structure LED 3. However, this manufacturing method is relatively complicated and inconvenient, and requires high skills of workers. It is difficult to ensure that the flexible film is tightly attached to the vertical structure LED so that pressure is maintained between the fourth electrode and the second electrode, which affects the reliability of the product. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide an LED array device based on a vertical structure LED, which can simplify the manufacturing process and easily make the flexible film close to the vertical structure LED to ensure that there is pressure between the fourth electrode and the second electrode, thereby improving its reliability. The technical solution adopted is as follows:

[0006] An LED array device based on vertical structure LEDs comprises a driving base plate, a flexible film and a plurality of vertical structure LEDs, wherein the flexible film is arranged on the outer side of the driving base plate, a first electrode is arranged on the outer side surface of the driving base plate, a light-transmitting second electrode is arranged on the inner side surface of the flexible film, the second electrode is arranged opposite to the first electrode and forms an electrode overlap region; each vertical structure LED is sandwiched between the driving base plate and the flexible film and is located within the corresponding electrode overlap region, a third electrode and a fourth electrode are respectively arranged on the inner side surface and the outer side surface of the vertical structure LED, and the third electrode forms a conductive connection with the first electrode; the characteristic is that: the flexible film and the driving base plate are bonded by a sealing rubber ring arranged around the electrode overlap region, the flexible film, the driving base plate and the sealing rubber ring together form a negative pressure cavity capable of generating a negative pressure effect; each vertical structure LED is located in the negative pressure cavity; the flexible film is tightly attached to each vertical structure LED under the negative pressure of the negative pressure cavity, so that each fourth electrode contacts and cooperates with the second electrode to form a conductive connection.

[0007] When manufacturing the above-mentioned LED array device, a plurality of first electrodes are firstly arranged on the outer side of the driving base plate, and then a plurality of vertical structure LEDs are arranged on the outer side of the driving base plate, and the third electrodes on the inner side of each vertical structure LED are respectively conductive with the corresponding first electrodes; then, the flexible film is aligned with the driving base plate, so that the second electrode on the flexible film and the first electrode on the driving base plate form an electrode overlap region, and a sealing rubber ring is arranged on the outer side of the driving base plate, and the sealing rubber ring is located around the electrode overlap region, and then the edge of the flexible film is pressed against the sealing rubber ring, so that the flexible film is bonded to the driving base plate through the sealing rubber ring, and at this time, the flexible film, the driving base plate and the sealing rubber ring jointly form a negative pressure cavity; then, the negative pressure cavity is evacuated to generate a negative pressure effect, and under the negative pressure effect of the negative pressure cavity, the flexible film is closely attached to each vertical structure LED by relying on the pressure of atmospheric pressure on the flexible film, thereby maintaining pressure between each fourth electrode and the second electrode, so that each fourth electrode maintains a good conductive connection with the second electrode. In the above manufacturing process, since it is only necessary to set the sealing rubber ring around the electrode overlapping area to connect the flexible film and form the negative pressure cavity, there is no need to apply glue around each LED device, thereby simplifying the manufacturing process. Moreover, after the negative pressure cavity is formed, it is only necessary to evacuate the negative pressure cavity to generate a negative pressure effect, so that the flexible film can automatically cling to each vertical structure LED under the action of negative pressure, and it is easy to make the flexible film cling to the vertical structure LED to ensure that pressure is maintained between each fourth electrode and the second electrode, thereby improving the reliability of the LED array device.

[0008] The LED array device is provided with a flexible film with a light-transmitting second electrode on the outside of the driving base plate, and a plurality of vertical structure LEDs are sandwiched between the driving base plate and the flexible film, so that the fourth electrode on the outside of each vertical structure LED is conductive with the second electrode, thereby forming a circuit of the LED array device; and the flexible film can rely on its own deformation to overcome the uneven morphology caused by the vertical structure LED, and serve as a support for the second electrode to ensure that the second electrode can be smoothly led out, and the second electrode and its related circuit are arranged on the flexible film, and are not prone to breakage; at the same time, the flexible film seals the driving circuit inside it, and can also protect the driving circuit. In addition, the flexible film can also carry a certain driving circuit, thereby reducing the complexity of the design of the driving circuit on the driving base plate.

[0009] As a preferred solution of the utility model, the LED array device further comprises an exhaust unit capable of evacuating the negative pressure cavity to form a negative pressure, and the exhaust unit is arranged on the driving bottom plate. Thus, after the negative pressure cavity is formed, the negative pressure cavity can be evacuated to form a negative pressure by the exhaust unit.

[0010] As a further preferred embodiment of the present invention, the air extraction part includes at least one air extraction hole arranged on the driving base plate, and the outer end opening of each air extraction hole is communicated with the negative pressure cavity. Usually, the inner end opening of each air extraction hole is connected to the vacuum extraction device through an air extraction pipe. After the negative pressure cavity is formed, the vacuum extraction device can vacuum each air extraction hole through the air extraction pipe to form a negative pressure in the negative pressure cavity, and finally seal the air extraction hole (it can be sealed with glue or a valve), thereby forming a sealed negative pressure cavity.

[0011] As a preferred solution of the utility model, the driving base plate is provided with a first driving circuit, the first electrode is the output end of the first driving circuit, and the outer surface of the driving base plate is provided with at least one conductive protrusion conductively connected to the first driving circuit; the flexible film is provided with a second driving circuit, the second electrode is the output end of the second driving circuit, and the second electrode contacts and cooperates with the conductive protrusion to form a conductive connection. Thus, the second driving circuit on the flexible film can be electrically connected to the first driving circuit of the driving base plate through a plurality of conductive protrusions provided on the driving base plate.

[0012] As a further preferred embodiment of the present invention, the conductive protrusion is disposed within the negative pressure cavity, and the second electrode of the flexible film is tightly attached to the outer end of the conductive protrusion under the negative pressure of the negative pressure cavity to form a conductive connection. Thus, the negative pressure generated by the negative pressure cavity can be utilized to press the contact end of the second drive circuit onto the conductive protrusion by relying on the pressure of atmospheric pressure on the flexible film, thereby forming a connection between the second drive circuit and the first drive circuit, and the manufacturing process is simpler and more feasible.

[0013] As a further preferred solution of the present invention, the conductive protrusion is a metal block or metal protrusion (such as a tin dot) welded on the outer side of the driving base plate.

[0014] The driving base plate may be a printed circuit board, a glass plate or a plastic plate (such as a polyimide film) having a partial display driving circuit (first driving circuit), and the first electrode is the output end of the first driving circuit, and the first electrodes are generally arranged in an array. The first driving circuit may be a vertical structure LED display driving circuit of static drive, dynamic drive or active drive. For example, when the driving base plate is a printed circuit board, a first driving circuit of a vertical structure LED static drive or dynamic drive may be set on the circuit board, which is connected to each first electrode, and the first electrode may be a metal pad on the circuit board. When the driving base plate is a glass plate or a plastic film, the first driving circuit may be an active driving circuit, which is a driving circuit based on a thin film transistor (TFT, including TFTs of types such as α-Si, polysilicon, IGZO, etc.). The active driving circuit used for vertical structure LED display driving is generally a high current driving circuit (similar to the active driving of OLED, allowing a large current to be output), which can independently control the output current or voltage of each first electrode to control the light emission of its vertical structure LED. When the driving base plate is a glass plate or a plastic film, the first electrode may be a metal or non-metal exposed conductor area or conductor block.

[0015] The flexible film may also be provided with a portion of the display drive circuit, that is, the second drive circuit, and the second electrode is the output end of the second drive circuit. For example, when the first drive circuit is a row drive circuit for dynamic driving of a vertical structure LED, the second drive circuit may be a column drive circuit that together constitutes a vertical structure LED dynamic drive; and when the first drive circuit is an active drive circuit, the second electrode may be a common electrode shared by all LEDs, and the second drive circuit may be an auxiliary circuit or a conductive film layer for enhancing the conductivity of the common electrode.

[0016] The vertical structure LED can be a vertical structure LED chip (or diaphragm) based on semiconductors such as GaAs, GaP, SiC, GaN, etc., and can be manufactured through existing vertical structure LED manufacturing processes. For example: its light-emitting semiconductor layer (such as P-type layer, N-type layer, quantum well layer) is generally grown epitaxially on an epitaxial substrate (such as sapphire), and finally peeled off from the epitaxial substrate through a peeling process (such as laser peeling). The P pole and N pole of the vertical structure LED chip are respectively located on two opposite surfaces of the diaphragm structure, wherein one surface as the light-emitting surface is the fourth electrode (generally the N pole), and the other surface is the third electrode (generally the P pole).

[0017] Generally, the third electrode can be the exposed surface of the semiconductor layer or a thin metal coating suitable for welding, such as a thin coating of gold, silver, copper, zinc, iron and alloys thereof with a thickness of 5nm to 1000nm, and the overall thickness of such a vertical structure LED is generally 1 to 20μm. In addition, the third electrode can also be a thicker conductor substrate bonded to the above semiconductor layer, such as a metal plate or a conductive silicon substrate, so that the overall thickness of the vertical structure LED can exceed 100μm.

[0018] The size of the vertical structure LED can be 5 to 500 μm (selected according to factors such as the array unit spacing), and its shape can be square, circular or other shapes.

[0019] As a preferred solution of the present invention, the flexible film is a plastic film with a thickness not exceeding 0.4 mm. Specifically, the flexible film may be a plastic film such as PET (polyethylene terephthalate), PI (polyimide), CPI (transparent polyimide), PC (polycarbonate) with a thickness not exceeding 0.4 mm. Specifically, in order to improve flexibility to better adapt to multiple vertical structure LED protrusions, it is preferred that the thickness of the plastic film is not greater than 0.3 mm, especially not greater than 0.2 mm. For example, a plastic film with a thickness of 0.05 to 0.2 mm can be selected. Generally, the plastic film is preferably a colorless and transparent plastic film, or it may also be a white light-transmitting plastic film with an optical diffusion effect.

[0020] As another preferred embodiment of the present invention, the flexible film is a transparent glass film with a thickness of no more than 0.2 mm. Generally speaking, a transparent glass film with a thickness of no more than 0.2 mm, especially no more than 0.1 mm, also has a certain degree of flexibility, thereby being able to adapt to multiple vertical structure LED protrusions. The flexible film is a glass film, which has better heat resistance, and thus it is easier to form a second electrode with better performance and the required driving circuit on the flexible film through high temperature processing.

[0021] As a preferred embodiment of the present invention, the second electrode is a transparent electrode formed of a transparent conductive oxide film. Specifically, the transparent conductive oxide film can be a film layer with conductivity and high transparency, such as indium tin oxide (ITO), aluminum zinc oxide (AZO), indium zinc gallium oxide (IGZO), etc., so that the second electrode has the advantages of good conductivity and high transparency.

[0022] As another preferred embodiment of the present invention, the second electrode is a transparent electrode formed of a nano silver wire coating, which can prevent the second electrode from breaking when the flexible film is pressed by the vertical structure LED, thereby increasing the yield of the vertical structure LED display.

[0023] Compared with the prior art, the utility model has the following advantages:

[0024] In this LED array device, the flexible film and the driving base plate are bonded together by a sealing rubber ring arranged around the electrode overlapping area. During the manufacturing process, since it is only necessary to arrange the sealing rubber ring around the electrode overlapping area, there is no need to apply glue around each LED device, thereby simplifying the manufacturing process. Moreover, after the negative pressure cavity is formed, it is only necessary to evacuate the negative pressure cavity to generate a negative pressure effect, so that the flexible film can automatically cling to each vertical structure LED under the negative pressure, which makes it easy to make the flexible film cling to the vertical structure LED, ensuring that pressure is maintained between each fourth electrode and the second electrode, thereby improving the reliability of the LED array device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of an LED array device according to a preferred embodiment of the utility model.

[0026] Figure 2 yes Figure 1 sectional view of .

[0027] Figure 3 yes Figure 1 The LED array device is shown as a schematic diagram of a state where the flexible film is separated from the sealing rubber ring. DETAILED DESCRIPTION

[0028] like Figure 1-Figure 3 As shown, the LED array device based on the vertical structure LED 3 includes a driving base plate 1, a flexible film 2 and a plurality of vertical structure LEDs 3. The flexible film 2 is arranged on the outer side of the driving base plate 1. The outer side surface of the driving base plate 1 is provided with a first electrode 11. The inner side surface of the flexible film 2 is provided with a light-transmitting second electrode 21. The second electrode 21 is arranged opposite to the first electrode 11 and forms an electrode overlapping area 100. Each vertical structure LED 3 is sandwiched between the driving base plate 1 and the flexible film 2 and is located within the corresponding electrode overlapping area 100. The inner side surface and the outer side surface of the vertical structure LED 3 are respectively provided with There are a third electrode 31 and a fourth electrode 41, and the third electrode 31 forms a conductive connection with the first electrode 11; the flexible film 2 and the driving base plate 1 are bonded by a sealing rubber ring 4 arranged around the electrode overlapping area 100, and the driving base plate 1, the flexible film 2 and the sealing rubber ring 4 together form a negative pressure cavity 200 that can generate a negative pressure effect; each vertical structure LED 3 is in the negative pressure cavity 200; the flexible film 2 is tightly attached to each vertical structure LED 3 under the negative pressure of the negative pressure cavity 200, so that each fourth electrode 41 contacts and cooperates with the second electrode 21 to form a conductive connection.

[0029] In this embodiment, at least one exhaust hole 101 is provided on the driving base plate 1, and the outer end opening of the exhaust hole 101 is in communication with the negative pressure cavity 200, and the inner end opening of the exhaust hole 101 is connected to a vacuum device through an exhaust pipe. After the negative pressure cavity 200 is formed, the vacuum device can evacuate the negative pressure cavity 200 through the exhaust pipe and the exhaust hole 101, so that the negative pressure cavity 200 forms a negative pressure, and finally the exhaust hole 101 is sealed with glue 102, thereby forming a closed negative pressure cavity 200.

[0030] A first driving circuit 12 is provided on the outer side of the driving base plate 1, and a first electrode 11 is an output end of the first driving circuit. A plurality of conductive protrusions 13 conductively connected to the first driving circuit 12 are provided on the outer side of the driving base plate 1; a second driving circuit (not shown) is provided on the flexible film 2, and a second electrode 21 is an output end of the second driving circuit. The second electrode 21 contacts and cooperates with the conductive protrusions 13 to form a conductive connection. Thus, the second driving circuit on the flexible film 2 can be electrically connected to the first driving circuit 12 of the driving base plate 1 through the plurality of conductive protrusions 13 provided on the driving base plate 1.

[0031] In this embodiment, the conductive protrusion 13 is a metal block or metal protrusion (such as a tin dot) welded on the outer surface of the driving bottom plate 1, and each conductive protrusion 13 is arranged in the negative pressure cavity 200. The second electrode 21 of the flexible film 2 is closely attached to the outer end of the conductive protrusion 13 under the negative pressure of the negative pressure cavity 200 to form a conductive connection. Therefore, the negative pressure generated by the negative pressure cavity 200 can be used to press the contact end of the second driving circuit onto the conductive protrusion 13 by relying on the pressure of atmospheric pressure on the flexible film 2, thereby forming a connection between the second driving circuit and the first driving circuit 12, and the manufacturing process is simpler and more feasible.

[0032] The following is a brief description of the manufacturing method of this LED array device:

[0033] During manufacturing, a plurality of first electrodes 11 are firstly arranged on the outer side of the driving base plate 1, and then a plurality of vertical structure LEDs 3 are arranged on the outer side of the driving base plate 1, and the third electrodes 31 on the inner side of each vertical structure LED 3 are respectively electrically connected with the corresponding first electrodes 11; then, the flexible film 2 is aligned with the driving base plate 1, so that the second electrode 21 on the flexible film 2 and the first electrode 11 on the driving base plate 1 form an electrode overlap region 100, and a sealing rubber ring 4 is arranged on the outer side of the driving base plate 1, and the sealing rubber ring 4 is located around the electrode overlap region 100, and then the edge of the flexible film 2 is pressed tightly onto the sealing rubber ring 4. The flexible film 2 is bonded to the driving base plate 1 through the sealing rubber ring 4. At this time, the flexible film 2, the driving base plate 1 and the sealing rubber ring 4 together form a negative pressure cavity 200; then, the negative pressure cavity 200 is evacuated through the exhaust hole 101 to generate a negative pressure effect, and then the exhaust hole 101 is sealed with glue 102; under the negative pressure of the negative pressure cavity 200, the flexible film 2 is tightly attached to each vertical structure LED 3 by relying on the pressure of atmospheric pressure on the flexible film 2, thereby maintaining pressure between each fourth electrode 41 and the second electrode 21, so that each fourth electrode 41 maintains a good conductive connection with the second electrode 21.

[0034] In addition, it should be noted that the names of the various parts of the specific embodiments described in this specification may be different, and any equivalent or simple changes made based on the structure, features and principles of the utility model patent are included in the protection scope of the utility model patent. The technical personnel in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.

Claims

1. An LED array device based on vertical structure LEDs, comprising a driving base plate, a flexible film and a plurality of vertical structure LEDs, wherein the flexible film is arranged on the outer side of the driving base plate, a first electrode is arranged on the outer side surface of the driving base plate, a light-transmitting second electrode is arranged on the inner side surface of the flexible film, the second electrode is arranged opposite to the first electrode and forms an electrode overlap region; each vertical structure LED is sandwiched between the driving base plate and the flexible film and is located within the corresponding electrode overlap region, a third electrode and a fourth electrode are respectively arranged on the inner side surface and the outer side surface of the vertical structure LED, and the third electrode is conductively connected to the first electrode; the characteristics are as follows: The flexible film and the driving base plate are bonded together by a sealing rubber ring arranged around the electrode overlapping area, and the flexible film, the driving base plate and the sealing rubber ring together form a negative pressure cavity that can generate a negative pressure effect; each of the vertical structure LEDs is in the negative pressure cavity; the flexible film is tightly attached to each vertical structure LED under the negative pressure of the negative pressure cavity, so that each fourth electrode contacts and cooperates with the second electrode to form a conductive connection.

2. The LED array device based on vertical structure LEDs according to claim 1, characterized in that: The LED array device further includes an exhaust unit capable of evacuating the negative pressure cavity to form a negative pressure, and the exhaust unit is disposed on the driving base plate.

3. The LED array device based on vertical structure LEDs according to claim 2, characterized in that: The air extraction part comprises at least one air extraction through hole arranged on the driving bottom plate, and the outer end opening of each air extraction through hole is communicated with the negative pressure cavity.

4. The LED array device based on vertical structure LEDs according to claim 1, characterized in that: The driving base plate is provided with a first driving circuit, the first electrode is an output end of the first driving circuit, and the outer surface of the driving base plate is provided with at least one conductive protrusion conductively connected to the first driving circuit; The flexible film is provided with a second driving circuit, the second electrode is an output end of the second driving circuit, and the second electrode contacts and cooperates with the conductive protrusion to form a conductive connection.

5. The LED array device based on vertical structure LEDs according to claim 4, characterized in that: The conductive protrusion is arranged in the negative pressure cavity, and the second electrode of the flexible film is tightly attached to the outer end of the conductive protrusion under the negative pressure of the negative pressure cavity to form a conductive connection.

6. The LED array device based on vertical structure LEDs according to claim 5, characterized in that: The conductive protrusions are metal blocks or metal bumps welded on the outer side of the driving base plate.

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