LED lamp bead, preparation method thereof and display screen

Abstract

The invention discloses an LED lamp bead, a preparation method thereof and a display screen, and relates to the field of semiconductor photoelectric devices. The LED lamp bead comprises a rectangular substrate, a front face pattern area arranged on the front face of the rectangular substrate, a first light-emitting unit, a first packaging adhesive layer and a back face pattern area arranged on the back face of the rectangular substrate. The front pattern area comprises a first electric connection area, a second electric connection area, a third electric connection area, a fourth electric connection area, a first die bond area, a second die bond area and a third die bond area; the first electric connection area, the first die bonding area, the fourth electric connection area, the second die bonding area and the second electric connection area are sequentially arranged along a first diagonal line; the third electric connection area, the third die bonding area and the fourth electric connection area are sequentially arranged along a second diagonal line; the back pattern area comprises a first pin area, a second pin area, a third pin area and a fourth pin area, and the front pattern area and the light-emitting chip are wrapped by the first packaging adhesive layer. By implementing the invention, the yield can be improved, and the driving device can be suitable for various driving modes.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor optoelectronic devices, and in particular to an LED lamp bead and a preparation method thereof, and a display screen. Background Art

[0002] The existing MIP LED device uses a flat BT substrate as a bracket. The substrate is divided into a front line, a back line and a substrate. The front line is used to bind the light-emitting chip and realize electrical interconnection. The back line is used to weld with the LED display module PCB. The front and back lines are connected and conducted through through holes. During preparation, the LED chip is fixed on the front line, and then molded and cut to form lamp beads that can emit RGB three-primary colors. The existing lamp bead chip layout is an RGB vertical column layout. This layout is prone to silver glue or insulating glue falling off, which may cause short circuits, or glue falling to the welding line position, resulting in poor welding and other problems. On the other hand, with the rapid development of display market technology, virtual pixel driving methods, diamond arrangement driving methods, etc. have emerged. The conventional lamp beads can only be driven by a single chip in a single lamp bead or three together. If virtual driving is performed, the display pixels will drop significantly, which is difficult to meet the use requirements. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an LED lamp bead and a preparation method thereof, which has a high yield rate and can be applied to a variety of driving modes to meet the use requirements of various occasions.

[0004] Another technical problem to be solved by the present invention is to provide a display screen with high display accuracy and capable of being driven in a variety of driving modes to meet the use requirements of various occasions.

[0005] In order to solve the above problems, the present invention discloses an LED lamp bead, which comprises:

[0006] Rectangular substrate;

[0007] A front graphic area, which is arranged on the front side of the rectangular substrate, the front graphic area includes a solid crystal area and an electrical connection area; the electrical connection area includes a first electrical connection area, a second electrical connection area, a third electrical connection area and a fourth electrical connection area, the solid crystal area includes a first solid crystal area, a second solid crystal area and a third solid crystal area; the first electrical connection area, the first solid crystal area, the fourth electrical connection area, the second solid crystal area and the second electrical connection area are arranged in sequence along a first diagonal line of the rectangular substrate; the third electrical connection area, the third solid crystal area and the fourth electrical connection area are arranged in sequence along a second diagonal line of the rectangular substrate;

[0008] a backside graphic area, comprising a first pin area, a second pin area, a third pin area and a fourth pin area, which are respectively arranged corresponding to the first electrical connection area, the second electrical connection area, the third electrical connection area and the fourth electrical connection area;

[0009] A first light-emitting unit, comprising a blue LED chip, a red LED chip and a green LED chip, wherein the first light-emitting unit is fixed to the die-bonding area and is electrically connected to the electrical connection area; and

[0010] A first packaging adhesive layer is disposed on the front side of the rectangular substrate and wraps the front graphic area and the first light-emitting unit.

[0011] As an improvement of the above technical solution, it also includes a second light-emitting unit and a second packaging glue layer; the second packaging glue layer is arranged between the first packaging glue layer and the rectangular substrate, and wraps the second light-emitting unit;

[0012] The solid crystal area also includes a fourth solid crystal area for fixing the second light emitting unit, the electrical connection area also includes a fifth electrical connection area for forming an electrical connection with the second light emitting unit, and the backside graphic area also includes a fifth pin area corresponding to the fifth electrical connection area.

[0013] As an improvement of the above technical solution, the second light-emitting unit is a blue light LED chip, and the second packaging glue layer is a yellow phosphor layer, so that the second light-emitting unit emits white light.

[0014] As an improvement of the above technical solution, it also includes a bowl cup, which is arranged around the second light-emitting unit, and the second packaging glue layer is filled in the bowl cup;

[0015] The height of the bowl is ≥250 μm.

[0016] As an improvement of the above technical solution, the rectangular substrate includes at least three first through holes and at least one second through hole penetrating the rectangular substrate, wherein the first through holes are arranged in a corner area of ​​the rectangular substrate, and the second through hole is arranged in a middle part of the rectangular substrate;

[0017] The first electrical connection area, the second electrical connection area, and the third electrical connection area are electrically connected to the first pin area, the second pin area, and the third pin area respectively through a conductive medium disposed in the first through hole;

[0018] The fourth electrical connection area is electrically connected to the fourth pin area through a conductive medium disposed in the second through hole.

[0019] As an improvement of the above technical solution, the first crystal-bonding area, the second crystal-bonding area, the third crystal-bonding area and the fourth electrical connection area are electrically connected via a connecting wire;

[0020] One electrode of the first light emitting unit is electrically connected to the electrical connection region, and the other electrode is electrically connected to the crystal bonding region.

[0021] As an improvement of the above technical solution, the rectangular substrate includes at least four first through holes penetrating the rectangular substrate, and the first through holes are arranged in the corner area of ​​the rectangular substrate; the first electrical connection area, the second electrical connection area, the third electrical connection area, and the fifth electrical connection area are electrically connected to the first pin area, the second pin area, the third pin area, and the fifth pin area respectively through the conductive medium arranged in the first through holes; and / or

[0022] The fourth solid crystal region is electrically connected to the fourth electrical connection region via a connection line; one electrode of the second light emitting unit is electrically connected to the fifth electrical connection region, and the other electrode is electrically connected to the fourth solid crystal region.

[0023] Correspondingly, the present invention also discloses a method for preparing an LED lamp bead, which is used to prepare the above-mentioned LED lamp bead, and comprises the following steps:

[0024] S1. Provide a rectangular substrate;

[0025] S2, forming a front graphic area on the front side of the rectangular substrate, and forming a back graphic area on the back side; the front graphic area includes a solid crystal area and an electrical connection area; the electrical connection area includes a first electrical connection area, a second electrical connection area, a third electrical connection area and a fourth electrical connection area, and the solid crystal area includes a first solid crystal area, a second solid crystal area and a third solid crystal area; the first electrical connection area, the first solid crystal area, the fourth electrical connection area, the second solid crystal area and the second electrical connection area are arranged in sequence along the first diagonal line of the rectangular substrate; the third electrical connection area, the third solid crystal area and the fourth electrical connection area are arranged in sequence along the second diagonal line of the rectangular substrate; the back graphic area includes a first pin area, a second pin area, a third pin area and a fourth pin area, which are respectively arranged corresponding to the first electrical connection area, the second electrical connection area, the third electrical connection area and the fourth electrical connection area;

[0026] S3, fixing the first light emitting unit to the die-bonding region and forming an electrical connection with the electrical connection region;

[0027] S4, forming a first packaging adhesive layer on the front side of the rectangular substrate.

[0028] Correspondingly, the present invention also discloses a display screen, which includes the above-mentioned LED lamp beads.

[0029] As an improvement of the above technical solution, it includes: a PCB board, LED lamp beads arranged in an array on the PCB board, and a protective adhesive layer covering the LED lamp beads.

[0030] The implementation of the present invention has the following beneficial effects:

[0031] 1. In an embodiment of the present invention, in the LED lamp bead, the first electrical connection area, the first solid crystal area, the fourth electrical connection area, the second solid crystal area, and the second electrical connection area in the front graphic are arranged in sequence along the first diagonal of the rectangular substrate; the third electrical connection area, the third solid crystal area, and the fourth electrical connection area are arranged in sequence along the second diagonal of the rectangular substrate; that is, the first solid crystal area, the second solid crystal area, and the third solid crystal area are arranged close to the four corners of the rectangular substrate, and the distance between them is greatly increased compared to the traditional straight-line arrangement. Therefore, based on this arrangement, even if there is glue throwing when fixing the blue LED chip, the red LED chip, and the green LED chip in the later stage, it is not easy to cause short circuit or poor welding, which effectively improves the manufacturing yield. In addition, based on this arrangement, each LED chip is arranged close to the four corners of the rectangular substrate, which also lays a good foundation for subsequent driving in various ways.

[0032] 2. In the LED lamp bead of one embodiment of the present invention, a fourth solid crystal area and a fifth electrical connection area are also provided on the rectangular substrate, and a second light-emitting unit is fixed in the fourth solid crystal area, which can emit white light and can be used as fill light to enhance the display brightness of the display screen and enrich the application scenarios.

[0033] 3. In the LED lamp bead in one embodiment of the present invention, five pin areas are formed on the back of the rectangular substrate, which can increase the product thrust during the subsequent welding process, prevent the lamp from being knocked, and further improve the heat dissipation performance of the packaging unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the front structure of an LED lamp bead in one embodiment of the present invention;

[0035] Figure 2 It is a schematic diagram of the back structure of an LED lamp bead in one embodiment of the present invention;

[0036] Figure 3 1 is a schematic diagram of the cross-sectional structure of an LED lamp bead in one embodiment of the present invention (cut along the first diagonal line);

[0037] Figure 4 Schematic diagram of the driving principle of a display screen in one embodiment of the present invention;

[0038] Figure 5 is a schematic diagram of the driving principle of a display screen in another embodiment of the present invention;

[0039] In the figure, 1 is a rectangular substrate, 11 is a solid crystal area, 111 is a first solid crystal area, 112 is a second solid crystal area, 113 is a third solid crystal area, 114 is a fourth solid crystal area, 12 is an electrical connection area, 121 is a first electrical connection area, 122 is a second electrical connection area, 123 is a third electrical connection area, 124 is a fourth electrical connection area, 125 is a fifth electrical connection area, 13 is a pin area, 131 is a first pin area, 132 is a second pin area, 133 is a third pin area, Pin area, 134 is the fourth pin area, 135 is the fifth pin area, 14 is a through hole, 141 is the first through hole, 142 is the second through hole, 15 is the first diagonal line, 16 is the second diagonal line, 17 is the connecting line; 2 is the first light-emitting unit, 21 is the blue light LED chip, 22 is the red light LED chip, 23 is the green light LED chip, 3 is the first packaging glue layer, 4 is the second light-emitting unit, 5 is the second packaging glue layer, 6 is the bowl cup, and 7 is the bonding wire. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in further detail below.

[0041] See also Figure 1 to Figure 3 In one embodiment of the present invention, an LED lamp bead is provided, which includes a rectangular substrate 1, a front graphic area arranged on the front side of the rectangular substrate 1, a first light-emitting unit 2 and a first packaging adhesive layer 3, and a back graphic area arranged on the back side of the rectangular substrate 1.

[0042] The rectangular substrate 1 is an insulating substrate, which may be a PCB board or a BT board, but is not limited thereto. The rectangular substrate 1 may be a square, a rectangle, or a rectangle with chamfered corners, but is not limited thereto.

[0043] Among them, the front graphic area includes a solid crystal area 11 and an electrical connection area 12. The solid crystal area 11 is used to fix the first light-emitting unit 2 (i.e., various LED chips), and the electrical connection area 12 is used to form an electrical connection with the first light-emitting unit 2. Specifically, each LED chip can be provided with two electrical connection areas 12 to respectively electrically connect the positive and negative electrodes of the LED chip, but is not limited thereto. Preferably, in one embodiment, one electrode of the LED chip is electrically connected to the solid crystal area 11, and the other electrode is electrically connected to the electrical connection area 12. Based on the above settings, the area of ​​the solid crystal area 11 can be expanded to improve the heat dissipation performance.

[0044] Specifically, multiple solid crystal areas 11 are insulated or electrically connected to each other. Preferably, multiple solid crystal areas 11 are electrically connected. Based on this setting, one can make multiple LED chips have a common positive or negative pole, simplify the structure of the front graphic area and the back graphic area, and the other can increase the heat dissipation area and optimize the reliability of LED lamp beads. Specifically, multiple electrical connection areas 12 are insulated or electrically connected to each other to achieve separate driving of multiple LED chips, thereby displaying different colors. Specifically, the electrical connection area 12 and the solid crystal area 11 are insulated from each other to prevent the LED chip from short-circuiting. Among them, the LED chip can be electrically connected to the solid crystal area 11 / electrical connection area 12 through a bonding wire 7 or a conductive bump, but is not limited to this.

[0045] The backside graphic area includes a pin area 13, which is arranged one-to-one with the solid crystal area 11 and / or the electrical connection area 12 and forms an electrical connection. Specifically, the solid crystal area 11 and / or the electrical connection area 12 can be electrically connected to the pin area 13 through a conductive medium arranged in a through hole 14 on the rectangular substrate 1, but is not limited thereto. The pin area 13 is used to pass current to light up the LED lamp bead.

[0046] The crystal-bonding area 11, the electrical connection area 12, and the pin area 13 are all conductive thin layers disposed on the surface of the rectangular substrate 1, for example, they can be copper foil formed by lamination, or conductive thin layers formed by screen printing, embossing, electroplating, etc., but are not limited thereto. Preferably, in one embodiment, the crystal-bonding area 11, the electrical connection area 12, and the pin area 13 are all copper foils, which can be formed into a specific pattern by lamination and etching processes.

[0047] Specifically, in one embodiment, the solid crystal area 11 includes a first solid crystal area 111, a second solid crystal area 112 and a third solid crystal area 113 to fix the RGB LED chips respectively. The electrical connection area 12 includes a first electrical connection area 121, a second electrical connection area 122, a third electrical connection area 123 and a fourth electrical connection area 124. The first electrical connection area 121, the first solid crystal area 111, the fourth electrical connection area 124, the second solid crystal area 112 and the second electrical connection area 122 are arranged in sequence along the first diagonal line 15 of the rectangular substrate 1; the third electrical connection area 123, the third solid crystal area 113 and the fourth electrical connection area 124 are arranged in sequence along the second diagonal line 16 of the rectangular substrate 1; that is, the first solid crystal area 111, the second solid crystal area 112 and the third solid crystal area 113 are arranged close to the four corners of the rectangular substrate 1, and the distance between them is greatly increased compared with the traditional straight line arrangement. Therefore, based on this arrangement, even if there is glue fall-off when fixing the blue LED chip 21, the red LED chip 22, and the green LED chip 23 later, it is not easy to cause short circuit or poor welding, which effectively improves the manufacturing yield. In addition, based on this arrangement, each LED chip is arranged close to the four corners of the rectangular substrate 1, which also lays a good foundation for subsequent driving in various ways.

[0048] Specifically, based on this embodiment, the first solid crystal area 111, the second solid crystal area 112, and the third solid crystal area 113 can be electrically connected or electrically insulated from each other, but are not limited thereto. Preferably, in one embodiment, the first solid crystal area 111, the second solid crystal area 112, and the third solid crystal area 113 are all connected to the fourth electrical connection area 124 through a connecting line 17. This allows multiple LED chips to be connected in parallel through one electrical connection area 12, simplifying the graphics; the other allows the heat generated by the LED chip to be quickly distributed to various positions of the rectangular substrate 1 through a highly thermally conductive metal thin layer (the first solid crystal area 111, the second solid crystal area 112, the third solid crystal area 113, and the fourth electrical connection area 124), preventing excessive concentration of thermal stress from causing gaps, such as water vapor, which damages the LED lamp beads, thereby improving the reliability of the LED lamp beads.

[0049] Specifically, in one embodiment, the first light-emitting unit 2 includes a blue LED chip 21, a red LED chip 22, and a green LED chip 23, which can be fixed in any solid crystal area 11 and electrically connected to the adjacent electrical connection area 12. Exemplarily, in one embodiment, the red LED chip 22 is fixed in the first solid crystal area 111, and its cathode is bonded to the first solid crystal area 111 through a conductive adhesive, and its anode is connected to the first electrical connection area 121 through a welding wire. The blue LED chip 21 is fixed in the second solid crystal area 112 through an insulating adhesive, and its cathode is electrically connected to the second solid crystal area 112 through a bonding wire 7, and its anode is electrically connected to the second electrical connection area 122 through a bonding wire 7. The green LED chip 23 is fixed in the third solid crystal area 113 through an insulating adhesive, and its cathode is electrically connected to the third solid crystal area 113 through a bonding wire 7, and its anode is electrically connected to the third electrical connection area 123 through a bonding wire 7. At the same time, the first crystal-bonding area 111 , the second crystal-bonding area 112 , the third crystal-bonding area 113 are electrically connected to the fourth electrical connection area 124 , so that the three LED chips share a common cathode.

[0050] Specifically, in one embodiment, the backside graphic area includes a first pin area 131, a second pin area 132, a third pin area 133 and a fourth pin area 134, which are respectively arranged in one-to-one correspondence with the first electrical connection area 121, the second electrical connection area 122, the third electrical connection area 123 and the fourth electrical connection area 124. Specifically, the first electrical connection area 121, the second electrical connection area 122, the third electrical connection area 123 and the fourth connection area can be electrically connected to the first pin area 131, the second pin area 132, the third pin area 133 and the fourth pin area 134 through a conductive medium arranged in a through hole 14 on the rectangular substrate 1, and the through hole 14 can be arranged in the corresponding electrical connection area 12, but is not limited thereto. Preferably, in one embodiment, the rectangular substrate 1 includes at least three first through holes 141 and at least one second through hole 142 penetrating the rectangular substrate 1, the first through hole 141 is arranged in the corner area of ​​the rectangular substrate 1, and the second through hole 142 is arranged in the middle of the rectangular substrate 1; the first electrical connection area 121, the second electrical connection area 122, and the third electrical connection area 123 are electrically connected to the first pin area 131, the second pin area 132, and the third pin area 133 respectively through the conductive medium arranged in the first through hole 141; the fourth electrical connection area 124 is electrically connected to the fourth pin area 134 through the conductive medium arranged in the second through hole 142. By arranging the first through hole 141 in the corner area of ​​the rectangular substrate 1, on the one hand, multiple rectangular substrates 1 can share one first through hole 141, simplifying the preparation process, and reducing the aperture of the first through hole 141, so that the volume of the LED lamp bead is smaller and the display accuracy is improved. Secondly, the distance between the through hole 14 and the die-bonding area 11 is increased, so as to avoid the glue being thrown to the area where the through hole 14 is located during the die-bonding, thereby improving the yield rate and the reliability of the LED lamp bead.

[0051] Preferably, in one embodiment, the LED lamp bead also includes a second light-emitting unit 4 and a second encapsulation adhesive layer 5; the second encapsulation adhesive layer 5 is arranged between the first encapsulation adhesive layer 3 and the rectangular substrate 1, and wraps the second light-emitting unit 4; the solid crystal area 11 also includes a fourth solid crystal area 114 for fixing the second light-emitting unit 4, the electrical connection area 12 also includes a fifth electrical connection area 125 for forming an electrical connection with the second light-emitting unit 4, and the back graphic area also includes a fifth pin area 135 corresponding to the fifth electrical connection area 125. The second light-emitting unit 4 cooperates with the second encapsulation adhesive layer 5 to emit white light, which can be used as fill light to improve the display brightness of the display screen and enrich the application scenarios. In addition, based on this embodiment, five pin areas can be formed on the back of the rectangular substrate 1, which can improve the product thrust in the subsequent welding process, prevent the lamp from knocking, and further improve the heat dissipation performance of the packaging unit. It should be noted that the LED packaging unit for the display screen needs to be welded to the PCB board later. The pin spacing in the traditional four-pin structure is large, and the thrust on the LED lamp bead is insufficient, which makes it easy to knock the lamp. The present invention increases the number of pin areas 13 to improve the product thrust.

[0052] Specifically, in one embodiment, the second light-emitting unit 4 may be a blue LED chip, and the second packaging layer 5 may be a yellow phosphor layer; in another embodiment, the second light-emitting unit 4 is a purple LED chip, and the second packaging layer is an RGB three-wavelength phosphor, but is not limited thereto.

[0053] Specifically, based on this embodiment, a cup 6 is further provided around the second light-emitting unit 4, in which glue is dispensed and cured to form a second encapsulation glue layer 5. Specifically, the cup 6 can be formed by a printing-etching process, but is not limited thereto. The height of the cup 6 is ≥250 μm, preferably 280 μm to 500 μm.

[0054] Specifically, based on this embodiment, the rectangular substrate 1 includes four first through holes 141 penetrating the rectangular substrate 1, and the first through holes 141 are arranged in the corner area of ​​the rectangular substrate 1; the first electrical connection area 121, the second electrical connection area 122, the third electrical connection area 123, and the fifth electrical connection area 125 are electrically connected to the first pin area 131, the second pin area 132, the third pin area 133, and the fifth pin area 135 respectively through the conductive medium arranged in the first through holes 141; the fourth solid crystal area 114 is electrically connected to the fourth electrical connection area 124 through the connecting line 17; one electrode of the second light-emitting unit 4 is electrically connected to the fifth electrical connection area 125, and the other electrode is electrically connected to the fourth solid crystal area 114.

[0055] Correspondingly, the present invention also discloses a method for preparing an LED lamp bead, which comprises the following steps:

[0056] S1, providing a rectangular substrate 1;

[0057] S2, forming a front pattern area on the front side of the rectangular substrate 1, and forming a back pattern area on the back side;

[0058] The front pattern area or the back pattern area can be formed by screen printing, embossing, electroplating, etc., but is not limited thereto. Preferably, in one embodiment, copper foil is first pressed on the surface of the rectangular substrate 1, and then etching is performed to form the back circuit pattern.

[0059] Preferably, in one embodiment, when the LED lamp bead includes the second light-emitting unit 4 , this step also includes the steps of screen printing, exposure and etching to form the bowl 6 .

[0060] S3, fixing the first light emitting unit 2 on the solid crystal area 11, and forming an electrical connection with the electrical connection area 12;

[0061] Specifically, the first light emitting unit 2 may be fixed to the die-bonding region 11 by using insulating glue or conductive glue, but the invention is not limited thereto.

[0062] Preferably, in one embodiment, when the LED lamp bead includes a second light-emitting unit 4 , this step also includes the step of fixing the second light-emitting unit 4 to the fourth die-bonding area 114 and forming a first packaging adhesive layer 3 .

[0063] S4 , forming a first packaging adhesive layer 3 on the front surface of the rectangular substrate 1 .

[0064] Correspondingly, the present invention also discloses a display screen, which includes the above-mentioned LED lamp beads. Preferably, it also includes a PCB board and a protective adhesive layer, wherein a plurality of LED lamp beads are arrayed on the PCB board and the protective adhesive layer covers the LED lamp beads. In addition, it should be noted that a preset distance is set between the plurality of LED lamp beads, and the protective adhesive layer covers the PCB board exposed by the distance.

[0065] The following is an explanation of the driving method of the LED lamp beads based on this embodiment. Figure 4-5 , for example, each display screen includes 6 groups of LED lamp beads (one row is a group, and each group contains a number of LED lamp beads). Figure 4 As shown, in driving mode 1, the RGB (LED chip) in each LED lamp bead is lit according to the display requirements (red triangle), but the blue LED chip in the LED lamp bead used to emit white light is not lit. In driving mode 2, the RGB (LED chip) in each LED lamp bead is lit according to the display requirements; at the same time, the blue LED chip in the LED lamp bead used to emit white light is lit, or a group of LED lamp beads are lit at intervals, or one or more LED lamp beads are lit at intervals to increase the brightness of the display. In driving mode 3, see Figure 5 , under better display effects, the RGB (LED chips) in the first group of LED lamp beads are normally lit, and the RGB (LED chips) in the second and third groups of LED lamp beads are driven in a borrowing manner (red triangle), but the blue LED chips used to emit white light in the LED lamp beads are not lit. This driving method can greatly reduce energy consumption, theoretically by 50%. In driving method four, while driving the RGB (LED chips) in the lamp beads in the manner of driving method three, the blue LED chips used to emit white light in the LED lamp beads can be all lit, or a group of LED lamp beads can be lit at intervals, or one or more LED lamp beads can be lit at intervals to increase the brightness of the display. In driving method five, only the blue LED chips used to emit white light in the LED lamp beads are fully or partially lit. Based on this driving method, whiteboard writing (touch screen) can be performed.

[0066] The above is a preferred embodiment of the invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the invention. These improvements and modifications are also considered to be within the scope of protection of the invention.

Claims

1. An LED lamp bead, characterized in that: include: Rectangular substrate; A front graphic area, which is arranged on the front side of the rectangular substrate, the front graphic area includes a solid crystal area and an electrical connection area; the electrical connection area includes a first electrical connection area, a second electrical connection area, a third electrical connection area and a fourth electrical connection area, the solid crystal area includes a first solid crystal area, a second solid crystal area and a third solid crystal area; the first electrical connection area, the first solid crystal area, the fourth electrical connection area, the second solid crystal area and the second electrical connection area are arranged in sequence along a first diagonal line of the rectangular substrate; the third electrical connection area, the third solid crystal area and the fourth electrical connection area are arranged in sequence along a second diagonal line of the rectangular substrate; a backside graphic area, comprising a first pin area, a second pin area, a third pin area and a fourth pin area, which are respectively arranged corresponding to the first electrical connection area, the second electrical connection area, the third electrical connection area and the fourth electrical connection area; A first light-emitting unit, comprising a blue LED chip, a red LED chip and a green LED chip, wherein the first light-emitting unit is fixed to the die-bonding area and is electrically connected to the electrical connection area; and A first packaging adhesive layer is disposed on the front side of the rectangular substrate and wraps the front graphic area and the first light-emitting unit.

2. The LED lamp bead according to claim 1, characterized in that: It also includes a second light-emitting unit and a second packaging glue layer; the second packaging glue layer is arranged between the first packaging glue layer and the rectangular substrate, and wraps the second light-emitting unit; The solid crystal area also includes a fourth solid crystal area for fixing the second light emitting unit, the electrical connection area also includes a fifth electrical connection area for forming an electrical connection with the second light emitting unit, and the backside graphic area also includes a fifth pin area corresponding to the fifth electrical connection area.

3. The LED lamp bead as claimed in claim 2, characterized in that: The second light emitting unit is a blue LED chip, and the second packaging glue layer is a yellow phosphor layer, so that the second light emitting unit emits white light.

4. The LED lamp bead according to claim 2 or 3, characterized in that: It also includes a bowl cup, which is arranged around the second light-emitting unit, and the second packaging glue layer is filled in the bowl cup; The height of the bowl is ≥250 μm.

5. The LED lamp bead according to claim 1, characterized in that: The rectangular substrate comprises at least three first through holes penetrating the rectangular substrate and at least one second through hole, wherein the first through holes are arranged in the corner area of ​​the rectangular substrate, and the second through hole is arranged in the middle of the rectangular substrate; The first electrical connection area, the second electrical connection area, and the third electrical connection area are electrically connected to the first pin area, the second pin area, and the third pin area respectively through a conductive medium disposed in the first through hole; The fourth electrical connection area is electrically connected to the fourth pin area through a conductive medium disposed in the second through hole.

6. The LED lamp bead according to claim 1, characterized in that: The first crystal-bonding area, the second crystal-bonding area, the third crystal-bonding area and the fourth electrical connection area are electrically connected via connecting wires; One electrode of the first light emitting unit is electrically connected to the electrical connection region, and the other electrode is electrically connected to the crystal bonding region.

7. The LED lamp bead as claimed in claim 2, characterized in that: The rectangular substrate comprises at least four first through holes penetrating the rectangular substrate, wherein the first through holes are arranged in the corner area of ​​the rectangular substrate; the first electrical connection area, the second electrical connection area, the third electrical connection area, and the fifth electrical connection area are electrically connected to the first pin area, the second pin area, the third pin area, and the fifth pin area respectively through the conductive medium arranged in the first through holes; and / or The fourth solid crystal region is electrically connected to the fourth electrical connection region via a connection line; one electrode of the second light emitting unit is electrically connected to the fifth electrical connection region, and the other electrode is electrically connected to the fourth solid crystal region.

8. A method for preparing an LED lamp bead, used for preparing the LED lamp bead as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Provide a rectangular substrate; S2, forming a front graphic area on the front side of the rectangular substrate, and forming a back graphic area on the back side; the front graphic area includes a solid crystal area and an electrical connection area; the electrical connection area includes a first electrical connection area, a second electrical connection area, a third electrical connection area and a fourth electrical connection area, and the solid crystal area includes a first solid crystal area, a second solid crystal area and a third solid crystal area; the first electrical connection area, the first solid crystal area, the fourth electrical connection area, the second solid crystal area and the second electrical connection area are arranged in sequence along the first diagonal line of the rectangular substrate; the third electrical connection area, the third solid crystal area and the fourth electrical connection area are arranged in sequence along the second diagonal line of the rectangular substrate; the back graphic area includes a first pin area, a second pin area, a third pin area and a fourth pin area, which are respectively arranged corresponding to the first electrical connection area, the second electrical connection area, the third electrical connection area and the fourth electrical connection area; S3, fixing the first light emitting unit on the die-bonding region and forming an electrical connection with the electrical connection region; S4, forming a first packaging adhesive layer on the front side of the rectangular substrate.

9. A display screen, characterized in that: It comprises the LED lamp bead as claimed in any one of claims 1 to 7.

10. The display screen according to claim 9, characterized in that: include: A PCB board, LED lamp beads arrayed on the PCB board, and a protective adhesive layer covering the LED lamp beads.

Images