Small pitch LED lamp beads, display screen

Abstract

The utility model discloses a small-pitch LED lamp bead and a display screen. The small-pitch LED lamp bead includes: a first insulating substrate; a second insulating substrate; a light-emitting chip, which includes a blue LED, a green LED and a red LED, wherein the blue LED and the green LED are fixed to the solid crystal area by insulating glue, and the red LED is fixed to the solid crystal area by conductive glue; a packaging glue layer, which is arranged above the second insulating substrate and the light-emitting chip; wherein the front of the first insulating substrate or the back of the second insulating substrate is provided with a pin heat dissipation area, which is arranged one-to-one with the pin area, and the first connecting through hole and the second connecting through hole are both provided with a conductive medium, so as to realize the electrical connection between the pin area and the welding wire area through the conductive medium and the pin heat dissipation. The solid crystal area is also provided with at least one third connecting through hole, and the third connecting through hole is also filled with a conductive medium, so as to realize the electrical connection between the solid crystal area and the pin area through the conductive medium and the pin heat dissipation area. The implementation of the utility model can improve the reliability of small-pitch LED lamp beads.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor optoelectronic devices, in particular to a small-pitch LED lamp bead and a display screen. Background Art

[0002] The existing LED packaging units for display screens generally fix blue LEDs, green LEDs, and red LEDs on a die-bonding area, and then form an electrical connection with the front circuit, and then form an electrical connection with the back pins through the front circuit. Since three LEDs are fixed in each packaging unit, the heat generation is relatively high, which puts higher requirements on the heat dissipation capacity of the packaging unit. However, the heat dissipation capacity of the existing packaging units is relatively poor, which makes it easy for gaps to form at the junction of the packaging glue layer and the die-bonding area due to excessive heat accumulation, making it easy for water vapor in the air to enter the interior of the packaging unit, causing the device to fail easily, and causing problems such as caterpillars and other poor display effects. In addition, insufficient heat dissipation capacity causes the lamp beads to age faster, shortening the service life of the lamp beads. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a small-pitch LED lamp bead, which can effectively enhance heat dissipation, improve the reliability of the LED packaging unit, and extend the service life.

[0004] In order to solve the above problems, the utility model discloses a small-pitch LED lamp bead, which includes:

[0005] A first insulating substrate, a pin area is provided on the back side thereof; a first connecting through hole penetrating through the first insulating substrate is provided in the pin area;

[0006] A second insulating substrate is arranged above the first insulating substrate, and a crystal fixing area and a wire bonding area are arranged on the front side thereof, the pin area and the wire bonding area are arranged correspondingly; a second connecting through hole penetrating the second insulating substrate is arranged in the wire bonding area;

[0007] A light-emitting chip, comprising a blue LED, a green LED and a red LED, wherein the blue LED and the green LED are fixed to the solid crystal region by insulating glue, and the red LED is fixed to the solid crystal region by conductive glue;

[0008] A packaging adhesive layer, which is arranged above the second insulating substrate and the light-emitting chip;

[0009] Among them, the front side of the first insulating substrate or the back side of the second insulating substrate is provided with a pin heat dissipation area, which is arranged one-to-one with the pin area, and the first connecting through hole and the second connecting through hole are both provided with a conductive medium, so as to realize the electrical connection between the pin area and the welding wire area through the conductive medium and the pin heat dissipation.

[0010] At least one third connecting through hole is also provided in the crystal bonding area, and the third connecting through hole is also filled with a conductive medium, so as to realize electrical connection between the crystal bonding area and the pin area through the conductive medium and the pin heat dissipation area.

[0011] As an improvement of the above technical solution, the back side of the first insulating substrate is provided with six mutually separated pin areas;

[0012] The front side of the first insulating substrate or the back side of the second insulating substrate is provided with six pin heat dissipation areas which are separated from each other and correspond to the pin areas one by one;

[0013] The front side of the first insulating substrate is provided with five mutually separated welding wire areas;

[0014] Wherein, a pin area is electrically connected to the die-bonding area.

[0015] As an improvement of the above technical solution, the solid crystal area is L-shaped or straight-shaped.

[0016] As an improvement of the above technical solution, the crystal-bonding area includes a first crystal-bonding area, a second crystal-bonding area and a third crystal-bonding area which are separated from each other;

[0017] The blue LED, green LED and red LED are fixed to the first crystal-bonding area, the second crystal-bonding area and the third crystal-bonding area in sequence.

[0018] As an improvement of the above technical solution, a die-bonding heat dissipation area is further provided on the front side of the first insulating substrate or the back side of the second insulating substrate, and the die-bonding heat dissipation area is connected to the die-bonding heat dissipation area via a conductive medium provided in the third connecting through hole;

[0019] The die-bonding heat dissipation area is connected to a pin heat dissipation area corresponding to a pin area that is electrically connected to the die-bonding area.

[0020] As an improvement of the above technical solution, a die-bonding heat dissipation area is further provided on the front side of the first insulating substrate or the back side of the second insulating substrate;

[0021] The solid crystal heat dissipation area includes a first solid crystal heat dissipation area, a second solid crystal heat dissipation area and a third solid crystal heat dissipation area which are arranged corresponding to the first solid crystal area, the second solid crystal area and the third solid crystal area, and the three are connected into a piece; and are connected to the pin heat dissipation area corresponding to the pin area which is electrically connected to the solid crystal area.

[0022] As an improvement of the above technical solution, a third connecting through hole is provided in the solid crystal region, and the third connecting through hole is provided in any one of the first solid crystal region, the second solid crystal region and the third solid crystal region.

[0023] As an improvement of the above technical solution, the cross sections of the first connecting through hole and the second connecting through hole overlap.

[0024] As an improvement of the above technical solution, the apertures of the first connecting through hole, the second connecting through hole and the third connecting through hole are ≤0.02 mm, so as to form a solid conductive medium through a copper plating process.

[0025] Correspondingly, the present invention also discloses a display screen, which includes the above-mentioned small-pitch LED lamp beads.

[0026] The implementation of this utility model has the following beneficial effects:

[0027] The small-pitch LED lamp beads of the utility model include a first insulating substrate and a second insulating substrate, a pin area is set on the back of the first insulating substrate, and a solid crystal area and a welding wire area are set on the front of the second insulating substrate; and a pin heat dissipation area is formed on the front of the first insulating substrate or the back of the second insulating substrate, which can effectively improve the heat dissipation of the small-pitch LED packaging unit, slow down the aging of the lamp beads, and also reduce the water vapor channel caused by inconsistent thermal expansion, thereby improving the air tightness of the lamp beads. The two, the electrical connection between the pin area and the welding wire area is formed by the conductive medium in the first connecting through hole and the second connecting through hole and the heat sink heat dissipation area, avoiding the need to set a large-aperture through hole on the edge of the flat bracket, reducing the water vapor channel and improving the air tightness. The combination of the two greatly improves the reliability of the lamp beads and improves the display effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the cross-sectional structure of a small-pitch LED lamp bead in one embodiment of the utility model;

[0029] Figure 2 This is a schematic diagram of the front structure of a small-pitch LED lamp bead in one embodiment of the utility model;

[0030] Figure 3 This is a schematic diagram of the back structure of a small-pitch LED lamp bead in one embodiment of the utility model;

[0031] Figure 4 It is a schematic diagram of the back structure of the second substrate in one embodiment of the utility model;

[0032] In the figure, 1 is a first insulating substrate; 11 is a pin area, 12 is a first connecting through hole, 13 is a pin heat dissipation area, 14 is a solid crystal heat dissipation area, 141 is a first solid crystal heat dissipation area, 142 is a second solid crystal heat dissipation area, 143 is a third solid crystal heat dissipation area, 2 is a second insulating substrate, 21 is a solid crystal area, 211 is a first solid crystal area, 212 is a second solid crystal area, 213 is a third solid crystal area, 22 is a welding wire area, 23 is a second connecting through hole, 24 is a third connecting through hole, 3 is a light-emitting chip, 31 is a blue light LED, 32 is a green light LED, 33 is a red light LED, 4 is a packaging glue layer, 5 is a conductive medium, and 6 is a bonding wire. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model is further described in detail below.

[0034] See also Figure 1 to Figure 4 The utility model provides a small-pitch LED lamp bead, which includes a first insulating substrate 1, a second insulating substrate 2, a light-emitting chip 3 and a packaging glue layer 4 stacked in sequence. Among them, the back of the first insulating substrate 1 is provided with a pin area 11, which is used for later welding with a PCB board. The front of the second insulating substrate 2 is provided with a solid crystal area 21 and a welding wire area 22, wherein the solid crystal area 21 is used to fix the light-emitting chip 3, and the welding wire area 22 and the pin area 11 are used together to form an electrical connection between the light-emitting chip 3. Specifically, in order to meet the color rendering requirements of the display screen, the light-emitting chip 3 of the small-pitch LED lamp bead includes a blue LED 31, a green LED 32 and a red LED, which together constitute a pixel unit. Among them, the blue LED 31 and the green LED 32 are fixed to the solid crystal area 21 by insulating glue, and the red LED is fixed to the solid crystal area 21 by conductive glue, and the electrodes of the blue LED 31 and the green LED 32 are electrically connected to the welding wire area 22. One electrode of the red LED is electrically connected to the die-bonding area 21 through the conductive adhesive, and the other electrode is electrically connected to the bonding wire area 22 .

[0035] Among them, in one embodiment, a pin heat dissipation area 13 is provided on the front side of the first insulating substrate 1, and it is arranged one-to-one with the pin area 11. A second connecting through hole 23 is provided in the welding wire area 22, which penetrates the second insulating substrate 2. A conductive medium 5 is provided in the second connecting through hole 23, and the conductive medium 5 also has a relatively good thermal conductivity, so as to achieve the connection between the welding wire area 22 and the pin heat dissipation area 13, and achieve heat dissipation. In addition, a first connecting through hole 12 is also provided in the pin area 11, and the conductive medium 5 is also filled therein, so as to realize the electrical connection between the welding wire area 22 and the pin area 11 corresponding to the blue light LED 31 and the green light LED 32 through the first connecting through hole 12, the conductive medium 5 in the second connecting through hole 23, and the pin heat dissipation area 13. In addition, at least one third connecting through hole 24 is also provided in the solid crystal area 21, and the third connecting through hole 24 is also filled with a conductive medium 5, so as to realize the electrical connection between the solid crystal area 21 where the red light LED is located and the pin area 11 through the conductive medium 5 and the pin heat dissipation area 13.

[0036] In another embodiment of the utility model, a pin heat dissipation area 13 is provided on the back of the second insulating substrate 2, which is arranged one-to-one with the pin area 11. A second connecting through hole 23 is provided in the welding wire area 22, which penetrates the second insulating substrate 2. A conductive medium 5 is provided in the second connecting through hole 23, and the conductive medium 5 also has a relatively good thermal conductivity, thereby realizing the connection between the welding wire area 22 and the pin heat dissipation area 13, and heat dissipation. In addition, a first connecting through hole 12 is also provided in the pin area 11, which is also filled with a conductive medium 5, and then the electrical connection between the welding wire area 22 and the pin area 11 corresponding to the blue light LED 31 and the green light LED 32 is realized through the first connecting through hole 12, the conductive medium 5 in the second connecting through hole 23 and the pin heat dissipation area 13. In addition, at least one third connecting through hole 24 is also provided in the solid crystal area 21, and the third connecting through hole 24 is also filled with a conductive medium 5, so as to realize the electrical connection between the solid crystal area 21 where the red light LED is located and the pin area 11 through the conductive medium 5 and the pin heat dissipation area 13.

[0037] Based on the above-mentioned small-pitch LED lamp beads, a pin heat dissipation area is introduced between the two insulating substrates, which can effectively improve the heat dissipation of the small-pitch LED packaging unit, slow down the aging of the lamp beads, and also reduce the water vapor channels caused by inconsistent thermal expansion, thereby improving the air tightness of the lamp beads. Secondly, the electrical connection between the pin area and the welding wire area is formed by the conductive medium in the first connecting through hole and the second connecting through hole and the heat sink heat dissipation area, thereby avoiding the need to set a large-aperture through hole on the edge of the flat bracket, reducing the water vapor channel and improving the air tightness. The combination of the two greatly improves the reliability of the lamp beads and improves the display effect.

[0038] Specifically, in one embodiment, six separate pin areas 11 are provided on the back of the first insulating substrate 1. More pin areas 11 can improve the product thrust in the subsequent welding process, prevent lamp knocking, and further improve the heat dissipation performance of the packaging unit. It should be noted that the small-pitch LED lamp beads used in the display screen need to be soldered to the PCB board later. The pin spacing in the traditional four-pin structure is large, and the thrust for the small-pitch LED lamp beads is insufficient, which makes it easy to knock the lamp. The utility model solves this problem by setting six pin areas. Furthermore, in order to better improve the product thrust, the six pin areas 11 are divided into two groups and distributed on both sides of the back of the first insulating substrate 1. The cross-sectional size of the pin areas 11 in the same group is the same and the spacing is uniform. The pin areas 11 in different groups are aligned one by one.

[0039] Accordingly, in this embodiment, five separate wire bonding areas 22 are provided on the front side of the second insulating substrate 2, which are respectively used to form electrical connections with the positive and negative electrodes of the blue LED 31, the green LED 32, and any one electrode of the red LED 33. Specifically, in one embodiment, the above electrical connections are formed by bonding wires 6. The other electrode of the red LED 33 is electrically connected through the solid crystal area 21.

[0040] Accordingly, in this embodiment, six separate pin heat dissipation areas 13 are provided on the front side of the first insulating substrate 1 or the back side of the second insulating substrate 2, which are arranged one by one corresponding to the pin areas 11. Preferably, the cross-sectional area of ​​the pin heat dissipation area 13 and the pin area 11 is larger than the cross-sectional area of ​​the wire bonding area 22 to further improve the heat dissipation performance.

[0041] The first connection through hole 12 and the second connection through hole 23 are distributed in the pin heat dissipation area 13, so as to form an electrical connection between the pin area 11 and the wire bonding area 11 through the conductive medium 5 filled in both and the pin heat dissipation area 13. Preferably, in one embodiment, the cross-sections of the first connection through hole 12 and the second connection through hole 23 overlap. Based on this arrangement, the first connection through hole 13 and the second connection through hole 23 can be formed by a drilling process, which simplifies the drilling process and improves production efficiency.

[0042] Specifically, in the utility model, the aperture of the first connecting through hole 12 and the second connecting through hole 23 is ≤0.05mm. Due to the introduction of the pin heat dissipation area, the current distribution is optimized and the adverse effects of heat generation are reduced. Therefore, the aperture of the connecting through hole is reduced, and the water vapor channel is reduced. It should be noted that in traditional small-pitch LED lamp beads, the aperture of the through holes located around the substrate is ≥0.2mm. Although ink is used to fill and block them later, more water vapor channels will still be formed, and the bonding performance between the ink and the packaging glue is relatively poor, which will also form water vapor channels.

[0043] Preferably, in one embodiment of the present invention, the apertures of the first connecting through hole 12 and the second connecting through hole 23 are ≤ 0.02 mm. Based on this aperture, a solid conductive medium 5 can be obtained by a copper plating process, further optimizing air tightness. More preferably, the apertures of the first connecting through hole 12 and the second connecting through hole 23 are 0.01 to 0.02 mm. If the aperture is too small, the amount of the conductive medium 5 is too small, and the electrical connection performance is weakened.

[0044] The corresponding aperture of the third connecting through hole 24 is ≤0.05 mm, preferably, ≤0.02 mm, so as to obtain a solid conductive medium 5 through the copper deposition process and further optimize the air tightness. More preferably, the aperture of the third connecting through hole 24 is 0.01-0.02 mm.

[0045] Specifically, the crystal-fixing area 21 includes a first crystal-fixing area 211, a second crystal-fixing area 212 and a third crystal-fixing area 213, which are respectively used to fix the blue light LED 31, the green light LED 32 and the red light LED. Among them, the first crystal-fixing area 211, the second crystal-fixing area 212 and the third crystal-fixing area 213 are connected to each other into pieces or are separately arranged. Preferably, in one embodiment, the first crystal-fixing area 211, the second crystal-fixing area 212 and the third crystal-fixing area 213 are separately arranged. Based on the above-mentioned setting scheme, the mixing of the glue used for fixing during the packaging process can be reduced, the color rendering performance of the LED packaging unit is optimized, and the yield rate is improved. It should be noted that traditional RGB pixel units generally require the use of an electroplating process to form a connection between the pins and the LED chip, so the solid crystal area needs to be connected into a piece and electroplated leads are set. The utility model greatly reduces the aperture of each connection hole by setting a heat sink heat dissipation area, a first connecting through hole, and a second connecting through hole, and uses a copper plating process to form a conductive medium, so there is no need for protruding electroplated leads, and the solid crystal areas of different light-emitting units are set separately.

[0046] Specifically, the solid crystal area 21 is L-shaped or straight-lined as a whole, but is not limited thereto. When the solid crystal area 21 is L-shaped as a whole, the third solid crystal area 213 extends to the wire bonding area 22 on one side, thereby connecting one end of the third connecting through hole 24 to a pin heat dissipation area 13, and then the red light LED 33 of the third solid crystal area 213 is electrically connected to the pin area 11 through the third connecting through hole 24, the pin heat dissipation area 13, and the first connecting through hole 12 arranged in the third solid crystal area 213. When the solid crystal area 21 is straight-lined, that is, the first solid crystal area 211, the second solid crystal area 212, and the third solid crystal area 213 are coaxially arranged and have the same size, a conductive line can be arranged between the third connecting through hole 24 of the third solid crystal area 213 and the first connecting through hole 12 in the pin area 11. Preferably, the solid crystal area 21 is L-shaped, and a third connecting through hole 24 coaxially arranged with the first connecting through hole 12 is arranged in the third solid crystal area 213. Based on the above arrangement, the first connecting through hole 12 and the third connecting through hole 24 can be formed by a drilling process, thereby simplifying the production process.

[0047] Preferably, in one embodiment of the present invention, a solid crystal heat dissipation area 14 is further provided on the front side of the first insulating substrate 1 or the back side of the second insulating substrate 2, which is arranged corresponding to the solid crystal area 21, and the solid crystal heat dissipation area 14 is connected to one of the pin heat dissipation areas 13. The pin area 11 arranged corresponding to the pin heat dissipation area 13 is used to form an electrical connection with the red light LED. Based on the above arrangement, not only the heat dissipation of the lamp bead is further enhanced, but also the electrical connection is realized, and the structural arrangement is simplified.

[0048] More preferably, the die-bonding heat dissipation zone 14 includes a first die-bonding heat dissipation zone 141 corresponding to the first die-bonding zone 211, a second die-bonding heat dissipation zone 142 corresponding to the second die-bonding zone 212, and a third die-bonding heat dissipation zone 143 corresponding to the third die-bonding zone 213. The first die-bonding heat dissipation zone 141, the second die-bonding heat dissipation zone 142, and the third die-bonding heat dissipation zone 143 can also be separately arranged or connected into pieces. Preferably, in one embodiment, the three are connected into a piece, and a pin heat dissipation zone 13 is connected, and the pin heat dissipation zone 13 corresponds to the pin zone 11 that is electrically connected to the die-bonding zone 21. Based on this setting, the heat dissipation performance of small-pitch LED lamp beads can be improved.

[0049] Specifically, the third connecting through hole 24 may be 1 to 3. When there is one, it may be arranged in any one of the first solid crystal area, the second solid crystal area and the third solid crystal area. When there are two, it may be distributed in any two of the first solid crystal area, the second solid crystal area and the third solid crystal area; when there are three, it is evenly distributed in the first solid crystal area, the second solid crystal area and the third solid crystal area. Preferably, in one embodiment, the number of the third connecting through hole 24 is 1, and it is arranged in the third solid crystal area, which can simplify the drilling process.

[0050] In summary, the small-pitch LED lamp beads of the utility model include a first insulating substrate and a second insulating substrate, a pin area is set on the back of the first insulating substrate, and a solid crystal area and a welding wire area are set on the front of the second insulating substrate; and a pin heat dissipation area is formed on the front of the first insulating substrate or the back of the second insulating substrate, which can effectively improve the heat dissipation of the small-pitch LED packaging unit, slow down the aging of the lamp beads, and also reduce the water vapor channels caused by inconsistent thermal expansion, thereby improving the air tightness of the lamp beads. In addition, the electrical connection between the pin area and the welding wire area is formed by the conductive medium in the first connecting through hole and the second connecting through hole and the heat sink heat dissipation area, thereby avoiding the need to set a large-aperture through hole on the edge of the flat bracket, reducing the water vapor channels and improving the air tightness. The combination of the two greatly improves the reliability of the lamp beads and improves the display effect.

[0051] The above is a preferred embodiment of the utility model. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the utility model. These improvements and modifications are also considered to be within the scope of protection of the utility model.

Claims

1. A small pitch LED lamp bead, characterized in that: include: A first insulating substrate, a pin area is provided on the back side thereof; a first connecting through hole penetrating through the first insulating substrate is provided in the pin area; A second insulating substrate is arranged above the first insulating substrate, and a crystal fixing area and a wire bonding area are arranged on the front side thereof, the pin area and the wire bonding area are arranged correspondingly; a second connecting through hole penetrating the second insulating substrate is arranged in the wire bonding area; A light-emitting chip, comprising a blue LED, a green LED and a red LED, wherein the blue LED and the green LED are fixed to the solid crystal region by insulating glue, and the red LED is fixed to the solid crystal region by conductive glue; A packaging adhesive layer, which is arranged above the second insulating substrate and the light-emitting chip; Among them, the front side of the first insulating substrate or the back side of the second insulating substrate is provided with a pin heat dissipation area, which is arranged one-to-one with the pin area, and the first connecting through hole and the second connecting through hole are both provided with a conductive medium, so as to realize the electrical connection between the pin area and the welding wire area through the conductive medium and the pin heat dissipation. At least one third connecting through hole is also provided in the crystal bonding area, and the third connecting through hole is also filled with a conductive medium, so as to realize electrical connection between the crystal bonding area and the pin area through the conductive medium and the pin heat dissipation area.

2. The small-pitch LED lamp bead according to claim 1, characterized in that: The back side of the first insulating substrate is provided with six pin areas separated from each other; The front side of the first insulating substrate or the back side of the second insulating substrate is provided with six pin heat dissipation areas which are separated from each other and correspond to the pin areas one by one; The front side of the first insulating substrate is provided with five mutually separated welding wire areas; Wherein, a pin area is electrically connected to the die-bonding area.

3. The small-pitch LED lamp bead according to claim 1, characterized in that: The crystal-fixing area is L-shaped or straight-shaped.

4. The small-pitch LED lamp bead according to claim 1 or 3, characterized in that: The crystal-bonding area includes a first crystal-bonding area, a second crystal-bonding area and a third crystal-bonding area which are separated from each other; The blue LED, green LED and red LED are fixed to the first crystal-bonding area, the second crystal-bonding area and the third crystal-bonding area in sequence.

5. The small-pitch LED lamp bead according to claim 2, characterized in that: A die-bonding heat dissipation area is also provided on the front side of the first insulating substrate or the back side of the second insulating substrate, and the die-bonding heat dissipation area is connected to the die-bonding heat dissipation area via a conductive medium provided in the third connecting through hole; The die-bonding heat dissipation area is connected to a pin heat dissipation area corresponding to a pin area that is electrically connected to the die-bonding area.

6. The small-pitch LED lamp bead according to claim 4, characterized in that: The front side of the first insulating substrate or the back side of the second insulating substrate is also provided with a die-bonding and heat-dissipating area; The solid crystal heat dissipation area includes a first solid crystal heat dissipation area, a second solid crystal heat dissipation area and a third solid crystal heat dissipation area which are arranged corresponding to the first solid crystal area, the second solid crystal area and the third solid crystal area, and the three are connected into a piece; and are connected to the pin heat dissipation area corresponding to the pin area which is electrically connected to the solid crystal area.

7. The small-pitch LED lamp bead according to claim 6, characterized in that: A third connecting through hole is provided in the solid crystal region, and the third connecting through hole is provided in any one of the first solid crystal region, the second solid crystal region and the third solid crystal region.

8. The small-pitch LED lamp bead according to claim 1, characterized in that: The cross sections of the first connecting through hole and the second connecting through hole overlap.

9. The small-pitch LED lamp bead according to claim 1, characterized in that: The apertures of the first connecting through hole, the second connecting through hole and the third connecting through hole are ≤0.02 mm, so as to form a solid conductive medium through a copper plating process.

10. A display screen, characterized in that: It comprises the small-pitch LED lamp bead as described in any one of claims 1 to 9.

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