Transparent screen

Abstract

To prevent a first connection column from affecting the transparency of a transparent screen.SOLUTION: A transparent screen includes a first circuit board, an LED chip, and a plurality of first connection columns. The first circuit board includes a first surface and a second surface that faces the first surface. The first circuit board includes a transparent part where some first penetration holes are provided, an attachment part where the penetration hole is not provided, and the first connection columns. The LED chip is attached to the attachment part on the first surface. The first connection column is attached to the attachment part on the second surface, and includes a first limiting bump. When the first connection column is attached to the attachment part on the second surface, the transparency of the transparent screen is not affected.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application cites a Chinese patent application entitled "Transparent Screen" No. 202420224769.0, filed on January 27, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the field of display screens, and in particular to transparent screens. [Background technology]

[0003] The continuous development of display technology has led to the emergence of LED transparent screens. LED transparent screens, a type of LED display screen, are characterized by high transparency, ultra-thinness, and light weight. Compared with traditional non-transparent LED display screens, they can be integrated into buildings, have less impact on indoor lighting, and are safer and more reliable to install. In recent years, LED transparent screens have been increasingly used in the field of architectural media, and can also be installed in glass showcases for window displays and other scenarios.

[0004] When LED transparent screens are used, multiple LED transparent screens are usually joined together to form a large display device. After joining existing LED transparent screens, the transparency at the connection points between the two adjacent LED transparent screens is poor, which negatively impacts the overall display effect. Summary of the Invention [Problem to be solved by the invention]

[0005] The problem that the present invention aims to solve is that after joining conventional LED transparent screens, the transparency at the connection points of two adjacent LED transparent screens is poor, which adversely affects the overall display effect. [Means for solving the problem]

[0006] The technical solutions adopted by the present invention are as follows:

[0007] A transparent screen, The LED chip includes a first circuit board, an LED chip, and a plurality of first connecting posts. The first circuit board has a first surface and a second surface opposite to the first surface, and the first circuit board multiple a transparent portion provided with the first through-hole and a mounting portion not provided with a through-hole, and the LED chip is mounted on the mounting portion of the first surface; A transparent screen, characterized in that the plurality of first connection posts are attached to the attachment portion of the second surface and have first limiting bumps.

[0008] Furthermore, the first connection post is attached to the left edge and / or the right edge of the first circuit board.

[0009] The device further includes a first limiting plate, the first limiting plate having a first mounting hole, the first connecting post being inserted into the first mounting hole, the first limiting bump being abutted against the first limiting plate, and the first limiting plate having a second through hole corresponding to the first through hole.

[0010] The device further includes a plurality of second connection pillars, the second connection pillars being attached to the mounting portion on the second surface, some of the second connection pillars transmitting electrical energy and the remaining second connection pillars transmitting signals, and the second connection pillars having second limiting bumps.

[0011] Furthermore, the second connection pillars and the first connection pillars are provided alternately in each row.

[0012] Furthermore, the first connection pillar and the second connection pillar are provided at a lower end of the first circuit board, The transparent screen further includes a second circuit board, one end of the second circuit board is welded to the first circuit board, and the other end of the second circuit board extends outside the first circuit board. The second circuit board is electrically connected to the first circuit board so as to be able to communicate signals. The second circuit board has a third through-hole that corresponds to the first through-hole. The second circuit board has a second accommodating hole and a third mounting hole. The first connecting post is insertable into the second accommodating hole, the second connecting post is insertable into the third mounting hole, and the second limiting bump abuts against the second circuit board.

[0013] Furthermore, the first connection pillar and the second connection pillar are provided at an upper end and / or a lower end of the first circuit board, The transparent screen further includes a second circuit board, the second circuit board having a third through-hole corresponding to the first through-hole, the second circuit board having a second accommodating hole and a third mounting hole, the first connecting post being insertable into the second accommodating hole, the second connecting post being insertable into the third mounting hole, and the second limiting bump abutting against the second circuit board.

[0014] The device further includes a second limiting plate, the second limiting plate having a fourth through hole corresponding to the first through hole, the second limiting plate having a fourth mounting hole and a fifth accommodating hole, the first connecting pillar passing through the third mounting hole and extending into the fourth mounting hole, the first limiting bump abutting against the second limiting plate, and the fifth accommodating hole corresponding to the second connecting pillar.

[0015] Furthermore, the first connection poles are attached to the upper end or / and lower end of the first circuit board, and a part of the first connection poles transmits electric energy, and the remaining part transmits signals; The transparent screen further includes a second circuit board, the second circuit board having a third through-hole corresponding to the first through-hole; A second accommodating hole is provided on the second circuit board, the first connecting post is inserted into the second accommodating hole, and the first limiting bump is abutted against the second circuit board, thereby transmitting electrical energy and signals between the first circuit board and the second circuit board.

[0016] Furthermore, the first connecting post is provided with an annular engaging groove, and the upper wall of the engaging groove serves as the first limiting bump.

[0017] Furthermore, the first mounting hole is a T-shaped hole, and the diameter of the hole at the end closer to the first circuit board is smaller than the diameter of the hole at the end farther from the first circuit board.

[0018] Furthermore, the first limiting plate is located at the joint of the second surfaces of two identical first circuit boards arranged side by side, the second through hole corresponds in position to the first through hole, and the diameter of the second through hole is equal to or larger than the diameter of the first through hole.

[0019] Furthermore, the first connection post is a copper post and is fixed to the first circuit board by welding, and the second connection post is a pogo pin.

[0020] Furthermore, a carbon fiber plate is provided on a second surface of the first circuit board, and a hole corresponding to the first through hole is provided in the carbon fiber plate, and an accommodating groove is provided in the carbon fiber plate at the welded portion between the first circuit board and the second circuit board. [Effects of the Invention]

[0021] As described above, the beneficial effects of the present invention are as follows:

[0022] The first connecting posts are attached to the attachment portions on the second surface, and therefore do not affect the transparency of the transparent screen. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram of an embodiment of a transparent screen. [Figure 2]FIG. 10 is a schematic diagram illustrating transparent screens that are adjacent in the left-right direction and joined together. [Figure 3] 1 is a schematic diagram of an embodiment of a transparent screen. [Figure 4] FIG. 10 is a schematic diagram illustrating transparent screens that are adjacent in the left-right direction and joined together. [Figure 5] FIG. 1 is a schematic diagram of an LED chip. [Figure 6] FIG. 4 is a schematic diagram of a first limiting plate. [Figure 7] 10 is a cross-sectional view of the first limiting plate and the first connecting post 3 when they are connected together. FIG. [Figure 8] FIG. 10 is a cross-sectional view of vertically adjacent transparent screens joined together. [Figure 9] FIG. 10 is a cross-sectional view of vertically adjacent transparent screens joined together. DETAILED DESCRIPTION OF THE INVENTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understandable, specific embodiments of the present invention will be described in detail below with reference to the drawings. In order to facilitate a full understanding of the present invention, many specific details are set forth in the following description. However, the present invention can be implemented in many ways different from those described in the present invention, and those skilled in the art can make similar improvements without departing from the scope of the present invention, so the present invention is not limited by the specific examples disclosed below.

[0025] It should be noted that when an element is said to be "fixed" to another element, it may be directly attached to the other element, or there may be intervening elements. When an element is said to be "connected" to another element, it may be directly attached to the other element, or there may be intervening elements.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used in the present specification are for describing specific embodiments and are not intended to limit the present invention. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0027] The transparent screen includes a first circuit board 1, an LED chip 2, and a plurality of first connecting posts 3, the first circuit board 1 having a first surface and a second surface opposite to the first surface, the first circuit board 1 having: multiple The transparent screen includes a transparent portion having a plurality of first through holes 101 and a mounting portion having no through holes, and the first through holes 101 penetrate the first surface and the second surface. The LED chips 2 are mounted to the mounting portion on the first surface. In some embodiments, the first through holes 101 are arranged in an array, and the LED chips 2 are also arranged in an array on the first circuit board 1. In some embodiments, the LED chips 2 are surrounded by four first through holes 101 (see FIG. 5 ). First connecting posts 3 are mounted to the mounting portion on the second surface, and the first connecting posts 3 have first limiting bumps 301. Because the first connecting posts 3 are mounted to the mounting portion on the second surface, the transparency of the transparent screen is not adversely affected.

[0028] 1, 2, and 7, in some embodiments, the first connecting post 3 is attached to the left and / or right end of the first circuit board 1 to facilitate joining of horizontally adjacent transparent screens. The transparent screen further includes a first limiting plate 4, which is provided with a second through-hole 401 corresponding to the first through-hole 101, thereby preventing the first limiting plate 4 from blocking the first through-hole 101 of the first circuit board 1 and reducing the transparency of the transparent screen. The first limiting plate 4 is provided with a first mounting hole 402, and when joining two horizontally adjacent transparent screens, the first connecting post 3 on the left side of one of the transparent screens is inserted into the first mounting hole 402, and the first limiting bump 301 abuts against the first limiting plate 4, thereby preventing the first connecting post 3 from slipping out of the first mounting hole 402. The first connecting post 3 on the other right side of the transparent screen is inserted into the first mounting hole 402, and the first limiting bump 301 abuts against the first limiting plate 4, thereby preventing the first connecting post 3 from slipping out of the first mounting hole 402. The first limiting plate 4 joins two adjacent transparent screens in the left-right direction, which is simple and convenient and does not affect the transparency of the transparent screens. In some embodiments, the first limiting plate 4 is made of an insulating material. Preferably, the first limiting plate 4 is made of a PC material. In some embodiments, the first mounting hole 402 is a T-shaped hole, and the diameter of the end closest to the first circuit board 1 is significantly smaller than the diameter of the end away from the first circuit board 1. The first connecting post 3 has an annular engaging groove 302, and the upper wall of the engaging groove forms the first limiting bump 301. The first limiting plate 4 is engaged with the engaging groove 302.

[0029] Here, since the first mounting hole 402 is T-shaped, the hole diameter increases from the end close to the first circuit board 1 toward the end away from the first circuit board 1, and the connection between the first mounting hole 402 of the first limiting plate 4 and the first connecting post 3 becomes stronger.

[0030] In one preferred embodiment of the present invention, the transparent screen is composed of at least two first circuit boards 1 arranged side by side, and the first limiting plate 4 is provided on the second surfaces of the two first circuit boards 1, specifically at the joint between the two first circuit boards 1, and the first connecting posts 3 on the second surfaces of the two first circuit boards 1 are inserted into the first mounting holes 402 on both the left and right sides of the first limiting plate 4, so that the two first circuit boards 1 are connected in an interlocked manner in the left-right direction, and the second through-holes 401 of the first limiting plate 4 correspond in position to the first through-holes 101, and the diameter of the second through-holes 401 is equal to or greater than the diameter of the first through-holes 101. Therefore, when the two first circuit boards 1 are connected side by side, the first limiting plate 4 does not adversely affect the transparency of the first circuit boards 1.

[0031] In the above embodiment, the first limiting bump 301 and the engaging groove 302 are located at the ends of the first connecting post 3 and the second connecting post 5 that are farther from the first circuit board 1, the engaging groove 302 is closer to the first circuit board 1, and the upper wall of the engaging groove 302 becomes the first limiting bump 301. When connecting the first circuit board 1 and the first limiting plate 4, the end of the first connecting post 3, i.e., the first limiting bump 301, passes through the first mounting hole 402 of the first limiting plate 4 and engages the first limiting plate 4 with the engaging groove 302, thereby ensuring the reliability of the connection between the first circuit board 1 and the first limiting plate 4.

[0032] As shown in FIGS. 1 , 2 , 8 , and 9 , in some embodiments, the transparent screen further includes a plurality of second connection posts 5, which are attached to the mounting portion on the second surface. Some of the second connection posts 5 transmit electrical energy, and the remaining second connection posts 5 transmit signals. The second connection posts 5 have second limiting bumps 501. The first connection posts 3 and the second connection posts 5 are provided at the lower end of the first circuit board 1. The transparent screen further includes a second circuit board 6, one end of which is welded to the first circuit board 1 and the other end of which extends outside the first circuit board 1, and the second circuit board 6 is electrically and signal-communicatively connected to the first circuit board 1. A third through-hole 601 is provided in the second circuit board 6, which corresponds to the first through-hole 101, thereby preventing the second circuit board 6 from affecting the transparency of the first circuit board 1 during bonding. The second circuit board 6 is provided with a second receiving hole 602 and a third mounting hole 603. When joining two vertically adjacent transparent screens, the second circuit board 6 at the upper end of one of the transparent screens is connected to the first connecting post 3 and the second connecting post 5 at the lower end of the other transparent screen, thereby connecting the two vertically adjacent transparent screens and establishing electrical and signal communication. Specifically, the first connecting post 3 can be inserted into the second receiving hole 602, and the second connecting post 5 can be inserted into the third mounting hole 603, and the second limiting bump 501 abuts against the second circuit board 6, thereby establishing electrical and signal communication between the two vertically adjacent transparent screens. To ensure a more stable connection between the two transparent screens, a second limiting plate 7 may be added to the surface of the second circuit board 6 away from the first circuit board 1. The second limiting plate 7 is provided with a fourth through-hole corresponding to the first through-hole 101. The second limiting plate 7 is provided with a fourth mounting hole and a fifth accommodating hole, the first connecting pillar 3 passes through the third mounting hole 603 and extends into the fourth mounting hole, and the first limiting bump 301 abuts against the second limiting plate 7, thereby preventing the first connecting pillar 3 from slipping out of the second limiting plate 7. The fifth accommodating hole corresponds to the second connecting pillar 5.In some embodiments, a carbon fiber plate is provided on the second surface of the first circuit board 1, and the carbon fiber plate has holes corresponding to the first through holes 101. The provision of the carbon fiber plate improves the strength of the transparent screen. At the welding locations between the first circuit board 1 and the second circuit board 6, a receiving groove is provided in the carbon fiber plate, so that the second circuit board 6 is provided between the first circuit board 1 and the carbon fiber plate. The second connecting posts 5 and the first connecting posts 3 are alternately arranged in rows, i.e., the rows of the first connecting posts 3 and the rows of the second connecting posts 5 are alternately arranged. The first connecting post 3 is provided with an annular engaging groove 302, and the upper wall of the engaging groove forms the first limiting bump 301. The second limiting plate 7 is engaged with the engaging groove 302.

[0033] Here, in the first circuit board 1, the first connection pillars 3 and the second connection pillars 5 may be provided only at the upper end, only at the lower end, or of course, at both the upper and lower ends. Here, the transparent screen having the first connection pillars 3 and the second connection pillars 5 provided at its upper end may extend upward to be connected to another transparent screen having the first connection pillars 3 and the second connection pillars 5 provided at its lower end, and the transparent screen having the first connection pillars 3 and the second connection pillars 5 provided at its lower end may extend downward to be connected to another transparent screen having the first connection pillars 3 and the second connection pillars 5 provided at its upper end. Similarly, the transparent screen having the first connection pillars 3 and the second connection pillars 5 provided at both the upper and lower ends may extend both upward and downward to be connected to another transparent screen above and below. When connecting the two transparent screens, the second circuit board 6 at the upper end of one of the transparent screens is connected to the first connecting pillar 3 and the second connecting pillar 5 at the lower end of the other of the transparent screens, thereby connecting the two adjacent transparent screens vertically and establishing electrical and signal communication conductivity.

[0034] Furthermore, by providing the carbon fiber plate on the second surface of the first circuit board 1, the strength of the first circuit board 1 is improved and the area of ​​the transparent screen can be increased. The carbon fiber plate has holes corresponding to the first through holes 101 of the first circuit board 1. These holes must also be through holes with a diameter smaller than that of the first through holes 101, thereby ensuring good transparency of the transparent screen. The carbon fiber plate also has a receiving groove, which is specifically provided at the welding position between the first circuit board 1 and the second circuit board 6. As a result, the second circuit board 6 is located between the first circuit board 1 and the carbon fiber plate, ensuring the flatness of the transparent screen.

[0035] In addition, in the above embodiments, the first limiting bump 301 and the engagement groove 302 are located at the end of the first connecting post 3 that faces away from the first circuit board 1, the second limiting bump 501 is located at the end of the second connecting post 5 that faces away from the first circuit board 1, and the second limiting bump 501 of the second connecting post 5 can extend to the third mounting hole 603 of the second circuit board 6, penetrate through the third mounting hole 603, and abut against the second circuit board 6. At the welding portion between the first circuit board 1 and the second circuit board 6, the ends of the first connecting pillar 3 and the second connecting pillar 5, i.e., the first limiting bump 301 and the second limiting bump 501, penetrate the second circuit board 6, the second limiting plate 7 engages with the engaging groove 302 of the first connecting pillar 3, and the second limiting bump 501 of the second connecting pillar 5 abuts against the second limiting plate 7, thereby ensuring the reliability of the connection between the first circuit board 1 and the second circuit board 6 and the first limiting plate 7.

[0036] 3 and 4, in some embodiments, the transparent screen further includes a plurality of second connection pillars 5, which are attached to the mounting portion on the second surface. Some of the second connection pillars 5 transmit electrical energy, and the remaining second connection pillars 5 transmit signals. The second connection pillars 5 have second limiting bumps 501. The first connection pillars 3 and the second connection pillars 5 are provided on the upper and lower ends of the first circuit board 1. The transparent screen further includes a second circuit board 6, which is provided with a third through-hole 601 corresponding to the first through-hole 101, and which is provided with a second receiving hole 602 and a third mounting hole 603. When joining two vertically adjacent transparent screens, the first connecting posts 3 and second connecting posts 5 at the bottom end of one of the transparent screens are connected to the second circuit board 6, and the first connecting posts 3 and second connecting posts 5 at the top end of the other transparent screen are connected to the second circuit board 6, thereby connecting the two vertically adjacent transparent screens and establishing electrical and signal communication. Specifically, the first connecting posts 3 of the two vertically adjacent transparent screens are inserted into the second accommodating holes 602. The second connecting posts 5 of the two vertically adjacent transparent screens can be inserted into the third mounting holes 603, and the second limiting bumps 501 are abutted against the second circuit board 6, thereby establishing electrical and signal communication between the two vertically adjacent transparent screens. To more stably connect the two transparent screens, a second limiting plate 7 may be added to the surface of the second circuit board 6 facing away from the first circuit board 1. The second limiting plate 7 has a fourth through-hole corresponding to the first through-hole 101. The second limiting plate 7 has a fourth mounting hole and a fifth receiving hole. The first connecting post 3 extends through the third mounting hole 603 and into the fourth mounting hole. The first limiting bump 301 abuts against the second limiting plate 7, thereby preventing the first connecting post 3 from slipping out of the second limiting plate 7. The fourth mounting hole and the third mounting hole overlap. In some embodiments, the fourth mounting hole is a T-shaped hole, and the diameter of the hole at the end closest to the first circuit board 1 is smaller than the diameter of the hole at the end farther from the first circuit board 1.The fifth receiving hole corresponds to the second connecting post 5 .

[0037] In some embodiments, the first connection pillar 3 is a copper pillar and is fixed to the first circuit board 1 by welding. Of course, the first connection pillar 3 may have other forms, for example, the first connection pillar 3 may be glued to the circuit board or screwed to the circuit board. The second connection pillar 5 is a pogo pin, specifically, the second connection pillar 5 is a pogo pin.

[0038] In some embodiments, the first connecting posts 3 are attached to the upper and / or lower ends of the first circuit board 1, with some of the first connecting posts 3 transmitting electrical energy and the remaining first connecting posts 3 transmitting signals. The transparent screen further includes a second circuit board 6, with a third through-hole 601 defined in the second circuit board 6, which corresponds to the first through-hole 101. The second circuit board 6 is defined with a second receiving hole 602. When joining two vertically adjacent transparent screens, the first connecting post 3 at the lower end of one of the transparent screens is connected to the second circuit board 6, and the first connecting post 3 at the upper end of the other transparent screen is connected to the second circuit board 6, thereby connecting the two vertically adjacent transparent screens and establishing electrical and signal communication therebetween. Specifically, the first connecting posts 3 of two vertically adjacent transparent screens are inserted into the second accommodating holes 602, and the first limiting bumps 301 are abutted against the second circuit board 6, thereby connecting the two vertically adjacent transparent screens and establishing electrical and signal communication conductivity.

[0039] The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A transparent screen, a first circuit board, an LED chip, and a plurality of first connecting posts; the first circuit board has a first surface and a second surface opposite to the first surface, the first circuit board includes a transparent portion having a plurality of first through holes and a mounting portion having no through holes, the LED chip is mounted to the mounting portion on the first surface, The transparent screen is characterized in that the plurality of first connection posts are attached to the attachment portions of the second surface and have first limiting bumps.

2. The transparent screen according to claim 1 , wherein the first connecting posts are attached to the left and / or right ends of the first circuit board.

3. 3. The transparent screen of claim 2, further comprising a first limiting plate, the first limiting plate having a first mounting hole, the first connecting post being inserted into the first mounting hole, the first limiting bump being abutted against the first limiting plate, the first limiting plate having a second through hole, the second through hole corresponding to the first through hole.

4. 2. The transparent screen of claim 1, further comprising a plurality of second connection pillars, the second connection pillars being attached to the mounting portion of the second surface, some of the second connection pillars transmitting electrical energy and the remainder of the second connection pillars transmitting signals, and the second connection pillars having second limiting bumps.

5. 5. The transparent screen according to claim 4, wherein the second connecting posts and the first connecting posts are alternately provided in each column.

6. the first connection pillar and the second connection pillar are provided at a lower end of the first circuit board; 5. The transparent screen of claim 4, further comprising a second circuit board, one end of the second circuit board welded to the first circuit board and the other end of the second circuit board extending outside the first circuit board, the second circuit board electrically connected to the first circuit board for signal communication, a third through hole provided in the second circuit board, the third through hole corresponding to the first through hole, a second accommodating hole and a third mounting hole provided in the second circuit board, the first connecting post being insertable into the second accommodating hole, the second connecting post being insertable into the third mounting hole, and the second limiting bump abutting against the second circuit board.

7. the first connection pillar and the second connection pillar are provided at an upper end and / or a lower end of the first circuit board; 5. The transparent screen of claim 4, further comprising a second circuit board, the second circuit board having a third through-hole corresponding to the first through-hole, the second circuit board having a second accommodating hole and a third mounting hole, the first connecting post being insertable into the second accommodating hole, the second connecting post being insertable into the third mounting hole, and the second limiting bump being abutted against the second circuit board.

8. The transparent screen of claim 6 or 7, further comprising a second limiting plate, wherein the second limiting plate is provided with a fourth through hole, the fourth through hole corresponding to the first through hole, the second limiting plate is provided with a fourth mounting hole and a fifth accommodating hole, the first connecting pillar extends through the third mounting hole and into the fourth mounting hole, the first limiting bump abuts against the second limiting plate, and the fifth accommodating hole corresponds to the second connecting pillar.

9. the first connection poles are attached to the upper end or / and the lower end of the first circuit board, a part of the first connection poles transmits electric energy, and the rest transmits signals; The transparent screen further includes a second circuit board, the second circuit board having a third through hole, the third through hole corresponding to the first through hole; The transparent screen according to any one of claims 1 to 3, characterized in that the second circuit board is provided with a second accommodating hole, the first connecting post is inserted into the second accommodating hole, and the first limiting bump is abutted against the second circuit board, thereby transmitting electrical energy and signals between the first circuit board and the second circuit board.

10. 2. The transparent screen according to claim 1, wherein the first connecting post is provided with an annular engaging groove, and an upper wall of the engaging groove is the first limiting bump.

11. 4. The transparent screen according to claim 3, wherein the first mounting hole is a T-shaped hole, and the diameter of the hole at the end closer to the first circuit board is smaller than the diameter of the hole at the end farther from the first circuit board.

12. The transparent screen of claim 3, characterized in that the first limiting plate is located at the joint of the second surfaces of two identical first circuit boards arranged left and right, the second through hole corresponds in position to the first through hole, and the diameter of the second through hole is equal to or greater than the diameter of the first through hole.

13. 7. The transparent screen according to claim 6, wherein the first connecting posts are copper posts fixed to the first circuit board by welding, and the second connecting posts are pogo pins.

14. 7. The transparent screen of claim 6, wherein a carbon fiber plate is provided on the second surface of the first circuit board, the carbon fiber plate has a hole corresponding to the first through hole, and the carbon fiber plate has an accommodating groove at a welding portion between the first circuit board and the second circuit board.

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