LED circuit boards and LED displays

Abstract

The present application provides an LED circuit board and an LED display screen, wherein the LED circuit board includes a substrate and a first solder pad, the first solder pad is arranged on the side of the substrate, a side of the first solder pad away from the substrate is provided with a welding area, a first hole is arranged on the LED circuit board, the first hole is located in the welding area, the first hole penetrates the first solder pad and at least partially extends into the substrate along the thickness direction of the substrate, a first reinforcement layer is arranged on the inner wall of the first hole, and the first reinforcement layer is connected to the first solder pad. The arrangement of the first reinforcement layer can provide forces of different directions to the first solder pad, thereby improving the connection stability between the first solder pad and the substrate; since the first reinforcement layer is connected to the first solder pad, the first reinforcement layer can be regarded as an extension of the first solder pad, and the first solder pad and the first reinforcement layer are inserted into the substrate as a whole like a nail, and even if the edge of the first solder pad is lifted after being hit, the first solder pad is not easy to fall off from the substrate, thereby reducing the difficulty of subsequent repair after the collision.

Description

Technical Field

[0001] The present invention relates to the field of LEDs, and more specifically, to an LED circuit board and an LED display screen. Background Art

[0002] As an important media advertising medium, LED display screen has the characteristics of high brightness, bright colors, high luminous efficiency, high contrast, short response time, wide operating temperature range and low energy consumption. It is widely used in stage display equipment, advertising display equipment, data visualization display equipment and commercial display equipment.

[0003] Reference Figure 1 The LED display screen includes an LED box, an LED circuit board 1' and lamp beads 2'. The lamp beads 2' are welded on the pads 11' of the LED circuit board 1', and the LED circuit board 1' is arranged in the LED box.

[0004] With the continuous advancement of technology, the LED display industry is gradually developing in the direction of small pitch and narrow frame. The distance between the lamp beads 2' of this type of LED display is smaller, and the lamp beads 2' are also closer to the edge of the LED box (LED circuit board 1'). During installation or transportation, the edge of the LED display is easily bumped, and the lamp beads 2' are easy to fall off under the impact of external force. Figure 1 , the pad 11' is combined with the LED circuit board 1' only through its lower surface. When the lamp bead 2' is knocked off, the pad 11' is easily torn off. If the number of pads 11' dropped is too large, the LED circuit board 1' will be directly scrapped; and for the LED circuit board 1' with a small number of pads 11' dropped and can be repaired, when repairing, it is also necessary to first remove the intact lamp bead 2' next to the damaged part, and then cut the FPC (Flexible Printed Circuit, flexible circuit board) pad 11' paper for welding and repair, and finally add all the lamp beads 2'. This repair method is not only costly, but also greatly reduces the product quality. Utility Model Content

[0005] The purpose of the embodiments of the present application is to provide an LED circuit board and an LED display screen to solve the technical problem in the prior art that the soldering pads of the soldered lamp beads on the LED circuit board are easily knocked off during installation or transportation.

[0006] To achieve the above purpose, the technical solution adopted in this application is:

[0007] In a first aspect, an LED circuit board is provided, comprising a substrate and a first soldering pad, wherein the first soldering pad is arranged on a side surface of the substrate, a welding area is arranged on a side surface of the first soldering pad away from the substrate, a first hole is arranged on the LED circuit board, the first hole is located in the welding area, the first hole passes through the first soldering pad and at least partially extends into the substrate along the thickness direction of the substrate, a first reinforcement layer is arranged on an inner wall of the first hole, and the first reinforcement layer is connected to the first soldering pad.

[0008] Optionally, the first hole passes through the substrate, and the LED circuit board further includes an insulating filler, the insulating filler is filled in the first hole, and the insulating filler is spaced apart from the first solder pad.

[0009] Optionally, a first insulating layer is provided on a side of the substrate away from the first pad, the second reinforcement layer is located between the first insulating layer and the substrate, and the first insulating layer extends toward the center of the first hole to form the insulating filling piece.

[0010] Optionally, a second reinforcement layer is disposed on a side of the substrate away from the first pad, and the first reinforcement layer is connected to the second reinforcement layer.

[0011] Optionally, the first hole penetrates the second reinforcement layer.

[0012] Optionally, the first pad includes a main layer and a protective layer, the main layer is arranged between the protective layer and the substrate, and the protective layer is an OSP protective layer or an immersion gold protective layer.

[0013] Optionally, the substrate includes a dielectric layer and a circuit layer, the first reinforcement layer is a metal layer, and the first reinforcement layer is connected to the control circuit on the circuit layer.

[0014] Optionally, a third reinforcement layer is further provided on the side of the substrate where the first pad is provided, and the third reinforcement layer is provided at an edge of the first pad and connected to the edge of the first pad.

[0015] Optionally, the first solder pad and the third reinforcement layer are integrally formed.

[0016] In a second aspect, an LED display screen is provided, comprising a lamp bead and the above-mentioned LED circuit board, wherein the lamp bead is welded on a first soldering pad of the LED circuit board.

[0017] The beneficial effect of the LED circuit board provided by the present application is that: the setting of the first reinforcement layer can provide adhesion in different directions for the first pad, so that the first pad is better attached to the substrate, thereby improving the connection stability between the first pad and the substrate; and, since the first reinforcement layer is connected to the first pad, the first reinforcement layer can be regarded as an extension of the first pad, and the first pad and the first reinforcement layer are inserted into the substrate as a whole like a nail. In this way, the setting of the first reinforcement layer increases the effective fixing area between the substrate and the first pad, improves the adhesion between the first pad and the substrate, and enhances the connection stability between the first pad and the substrate. Even if the edge of the first pad is lifted after being hit, the first pad is not easy to fall off from the substrate, which effectively reduces the risk of the first pad falling off due to the impact of external force on the lamp bead or the substrate, improves the reliability and stability of the use of the LED circuit board, and also helps to reduce maintenance and repair costs. In addition, by setting the first hole in the welding area, there is no need to increase the size of the welding pad, so that the spacing between the welding pads will not increase, and the spacing between the lamp beads will not increase, thus meeting the design requirements of small spacing between the lamp beads. When the LED circuit board is used in an LED display, the delicate picture effect of the LED display can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 It is a schematic diagram of an LED circuit board and lamp beads in the prior art;

[0020] Figure 2 A schematic diagram of an LED circuit board provided in one embodiment of the present application;

[0021] Figure 3 for Figure 2 A magnified schematic diagram of point A;

[0022] Figure 4 A schematic diagram of an LED circuit board provided in yet another embodiment of the present application;

[0023] Figure 5 for Figure 4 An enlarged schematic diagram of point B;

[0024] Figure 6 A schematic diagram of an LED circuit board and lamp beads provided in an embodiment of the present application;

[0025] Figure 7 for Figure 6An enlarged schematic diagram of point C;

[0026] Figure 8 A partial schematic diagram of an LED circuit board provided in an embodiment of the present application (the second insulating layer and the control circuit are not shown).

[0027] Among them, the reference numerals in the figures are as follows:

[0028] 1', LED circuit board; 11', solder pad; 2', lamp beads;

[0029] 1. LED circuit board; 11. first solder pad; 111. main body layer; 112. protective layer; 113. welding area; 12. second solder pad; 13. substrate; 131. dielectric layer; 132. circuit layer; 133. first side; 134. second side; 135. first hole; 1351. first reinforcement layer; 1352. second reinforcement layer; 136. second hole; 1361. first connection layer; 1362. second connection layer; 1363. third connection layer; 14. third reinforcement layer; 15. first insulating layer; 151. insulating filler; 16. second insulating layer; 17. third solder pad; 2. lamp beads; 3. IC chip. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] Please also read Figure 2 and Figure 3 (For some reference numerals, please refer to Figure 6 ), the LED circuit board 1 (Light Emitting Diode Display, LED, light emitting diode) provided in the embodiment of the present application is now described. The LED circuit board 1 of the present application includes a substrate 13 and a first solder pad 11, the first solder pad 11 is arranged on the side of the substrate 13, a side of the first solder pad 11 away from the substrate 13 is provided with a welding area 113, a first hole 135 is provided on the LED circuit board 1, the first hole 135 is located in the welding area 113, the first hole 135 passes through the substrate 13 and the first solder pad 11, and a first reinforcement layer 1351 is provided on the inner wall of the first hole 135, and the first reinforcement layer 1351 is connected to the first solder pad 11.

[0035] It can be understood that in this embodiment, the welding area 113 on the first soldering pad 11 is used to weld components. For example, the welding area 113 can be used to weld lamp beads 2, chips, etc. The first soldering pad 11 is welded and fixed to the components, thereby achieving a fixed connection between the components and the LED circuit board 1.

[0036] In the LED circuit board 1 provided in the present application, the inner wall of the first hole 135 is provided with a first reinforcement layer 1351, and the first reinforcement layer 1351 forms an angle with the first soldering pad 11. If the connection force between the first soldering pad 11 and the substrate 13 is recorded as F1, and the connection force between the first reinforcement layer 1351 and the hole wall of the first hole 135 is recorded as F2, then there is an angle between F2 and F1, that is, the setting of the first reinforcement layer 1351 can provide adhesion forces in different directions for the first soldering pad 11, so that the first soldering pad 11 can be better attached to the substrate 13, thereby improving the connection stability between the first soldering pad 11 and the substrate 13; and, since the first reinforcement layer 1351 is connected to the first soldering pad 11, the first reinforcement layer 1351 can be regarded as an extension of the first soldering pad 11, and the first soldering pad 11 and the first reinforcement layer 1351 are inserted into the substrate 13 as a whole like a nail. In this way, the setting of the first reinforcement layer 1351 increases the effective fixing area between the substrate 13 and the first pad 11, improves the adhesion between the first pad 11 and the substrate 13, and enhances the connection stability between the first pad 11 and the substrate 13. Even if the edge of the first pad 11 is lifted after being hit, the first pad 11 is not easy to fall off from the substrate 13, which effectively reduces the risk of the first pad 11 falling off due to the impact of the lamp bead 2 or the substrate 13 by external force, improves the reliability and stability of the use of the LED circuit board 1, and also helps to reduce the maintenance and repair costs. In addition, by setting the first hole 135 in the welding area 113, there is no need to increase the size of the pad, so that the spacing between the pads can be kept from becoming larger, thereby not causing the spacing between the lamp beads 2 to increase, meeting the design requirements of small spacing between the lamp beads 2, and when the LED circuit board 1 is used in an LED display screen, the detailed picture effect of the LED display screen can be guaranteed.

[0037] In the present embodiment, the first hole 135 passes through the substrate 13. At this time, the first hole 135 can be formed by drilling with a drill bit, and there is no need to precisely position the drilling depth of the drill bit, which is beneficial for controlling the processing cost of the LED circuit board 1. Of course, in other embodiments, the first hole 135 can also be formed by laser drilling.

[0038] In this embodiment, the first pad 11 includes a main body layer 111 and a protective layer 112. The main body layer 111 is arranged between the protective layer 112 and the substrate 13. The protective layer 112 is an OSP protective layer 112 or an immersion gold protective layer 112. Specifically, the main body layer 111 is a copper layer, and the main body layer 111 is processed by an OSP process (Organic Solderability Preservatives) or an immersion gold process to form the protective layer 112. Compared with the tin-spraying process, the surface flatness of the first pad 11 processed by the OSP process or the immersion gold process is higher, which can reduce the influence of the setting of the first hole 135 on the welding of the lamp bead 2, and reduce the possibility of the lamp bead 2 being tilted and having color cast due to mounting.

[0039] In this embodiment, the first solder pad 11 on the LED circuit board 1 is used to solder the lamp bead 2. During processing, it is necessary to first form a first hole 135 on the LED circuit board 1, and then process the main layer 111 using the OSP process or the immersion gold process.

[0040] In this embodiment, the substrate 13 has a first side surface 133 and a second side surface 134, the first side surface 133 and the second side surface 134 are arranged opposite to each other, the first side surface 133 is a TOP surface, that is, the top surface of the substrate 13, for mounting the lamp bead 2, the first solder pad 11 is arranged on the first side surface 133, and the second side surface 134 is a BOTTOM surface, that is, the bottom surface of the substrate 13, Figure 4 and Figure 5 The first hole 135 passes through the substrate 13, that is, the first hole 135 passes through the top surface and the side surface of the substrate 13, and a second reinforcement layer 1352 is provided on a side surface of the substrate 13 away from the first solder pad 11 (that is, the second side surface 134 of the substrate 13), and the first reinforcement layer 1351 is connected to the second reinforcement layer 1352.

[0041] In this embodiment, the second reinforcement layer 1352 and the first solder pad 11 are respectively located on both sides of the substrate 13. The second reinforcement layer 1352 can limit the movement of the first solder pad 11 in the thickness direction of the substrate 13. At this time, the first solder pad 11, the first reinforcement layer 1351 and the second reinforcement layer 1352 are fixed to the substrate 13 as a whole like rivets, which further improves the connection stability between the first solder pad 11 and the substrate 13 and reduces the probability of the first solder pad 11 falling off after a collision.

[0042] In this embodiment, the length of the first hole 135 extends along the thickness direction of the substrate 13 as indicated by the double-headed arrow X in the figure, that is, the first hole 135 is perpendicular to the first pad 11 .

[0043] Reference Figure 4 and Figure 5In the present embodiment, the first hole 135 passes through the substrate 13, and a plurality of second reinforcement layers 1352 are provided on a side of the substrate 13 away from the first solder pad 11 (i.e., the second side 134 of the substrate 13), and all the second reinforcement layers 1352 are arranged at intervals in a direction parallel to the second side 134, and a second reinforcement layer 1352 is provided for each first solder pad 11, that is, the first solder pad 11 and the second reinforcement layer 1352 correspond one to one.

[0044] In some embodiments, the first hole 135 passes through the second reinforcement layer 1352. In this embodiment, the first hole 135 is formed by a drill, and the first hole 135 is set to pass through the second reinforcement layer 1352, which can reduce the difficulty of drilling process and help reduce the processing cost of the LED circuit board 1.

[0045] Reference Figure 5 In some embodiments, the first hole 135 passes through the substrate 13, and the LED circuit board 1 further includes an insulating filler 151, which is filled in the first hole 135 and is spaced apart from the first pad 11. Figure 6 and Figure 7 In this embodiment, the first solder pad 11 is used for welding connection with the lamp bead 2, and the LED circuit board 1 is applied to the LED display screen. The setting of the insulating filler 151 can fill and block the first hole 135 to prevent the soldering material from flowing out from the first hole 135 to the back side of the substrate 13 (i.e., the side of the substrate 13 away from the first solder pad 11) during the welding process, reduce the loss of soldering material, reduce the probability of cold soldering between the first solder pad 11 and the lamp bead 2, and improve the connection quality between the first solder pad 11 and the lamp bead 2. In particular, for the LED circuit board 1 used outdoors, after welding, it is necessary to use packaging glue to package the lamp bead 2. Since the insulating filler 151 is provided to block the first hole 135, the packaging glue will not flow out of the first hole 135, and the packaging effect of the lamp bead 2 is also improved.

[0046] It is understandable that the insulating filler 151 cannot hinder the welding of the first soldering pad 11 and the lamp bead 2 . Therefore, the insulating filler 151 needs to be spaced apart from the first soldering pad 11 to ensure the welding connection quality between the first soldering pad 11 and the lamp bead 2 .

[0047] In this embodiment, the LED circuit board 1 is applied to a high-resolution LED display screen. Therefore, it is necessary to arrange small and dense lamp beads 2 on the LED circuit board 1. Then, the size of the first solder pad 11 on the LED circuit board 1 is also small, and the arrangement is also dense. The aperture of the first hole 135 needs to be appropriately adjusted according to the size of the first solder pad 11. For example, the aperture of the first hole 135 can be 0.2 mm. Since the aperture of the first hole 135 is small, the insulating filler 151 is directly set on the LED circuit board 1, which can simplify the welding steps and reduce the difficulty of alignment during the welding operation, thereby reducing the processing cost of the LED display screen and the subsequent maintenance cost.

[0048] Of course, in other embodiments, the LED circuit board 1 may not be provided with the insulating filler 151. For example, other methods may be used to prevent the soldering material from flowing out of the first hole 135. For example, an auxiliary plate may be used, and a plurality of protrusions may be provided on the auxiliary plate. When welding the lamp bead 2 and the first solder pad 11, the auxiliary plate and the LED circuit board 1 are overlapped, and the protrusions on the auxiliary plate are inserted into the first hole 135 to achieve the blocking of the first hole 135. Alternatively, the first hole 135 may not pass through the substrate 13, for example, the first hole 135 may be provided as a blind hole, so that the insulating filler 151 is not required to fill and block the first hole 135, which helps to simplify the structure of the LED circuit board 1.

[0049] Reference Figure 4 and Figure 5 In some embodiments, a first insulating layer 15 is disposed on the second side surface 134 of the substrate 13 , and the first insulating layer 15 extends toward the center of the first hole 135 to form an insulating filler 151 .

[0050] In this embodiment, a control circuit is provided on the second side 134 of the substrate 13. The control circuit of the second side 134 can be connected to the first solder pad 11, so as to realize power on and off and brightness control of the lamp bead 2. A first insulating layer 15 is provided. The first insulating layer 15 can cover the control circuit of the second side 134 of the substrate 13 to prevent the control circuit of the second side 134 from contacting with external conductive components and causing a short circuit.

[0051] In this embodiment, the first insulating layer 15 can be formed by curing solder resist ink. During processing, the end of the first hole 135 close to the first pad 11 can be filled and sealed with a filler, and then the solder resist ink is applied to the second side 134 of the substrate 13. During the coating process, the solder resist ink can enter the first hole 135 (since the end of the first hole 135 close to the first pad 11 is also provided with a filler, the solder resist ink does not fill the entire first hole 135). After the solder resist ink is cured, the filler in the first hole 135 is removed to form the first insulating layer 15 and the insulating filler 151. At this time, the first insulating layer 15 and the insulating filler 151 are integrally formed, and the first insulating layer 15 is connected to the insulating filler 151. The insulating filler 151 is restricted by the connection of the first insulating layer 15 and will not move in the first hole 135. In this way, the insulating filler 151 can be prevented from contacting the first pad 11, and the insulating filler 151 can be prevented from affecting the welding of the first pad 11 and the lamp bead 2.

[0052] Of course, in other embodiments, the insulating filler 151 may also be made of other materials, such as insulating glue, and the first hole 135 is filled with insulating glue, and the insulating filler 151 is formed after the insulating glue is cured.

[0053] In a specific embodiment, the filling length of the insulating filler 151 in the first hole can be half of the depth of the first hole 135, or can be other lengths. There is no single limitation on the filling length, as long as the insulating filler 151 can be spaced apart from the first pad 11 and can be adapted to block the opening of the first hole 135 away from the first pad 11.

[0054] In some embodiments, the first side 133 of the substrate 13 is also provided with a control circuit, and the first pad 11 may also be connected to the control circuit of the first side 133. Accordingly, the first side 133 of the substrate 13 is also provided with a second insulating layer 16. The second insulating layer 16 can separate the control circuit of the first side 133 from the external environment to prevent the control circuit of the first side 133 from contacting with external conductive components and causing a short circuit; optionally, the second insulating layer 16 is formed by curing the solder resist ink.

[0055] In the related art, the substrate 13 generally includes at least two dielectric layers 131 and at least one circuit layer 132. A control circuit is also arranged inside the substrate 13. A circuit layer 132 is arranged between two adjacent dielectric layers 131. A control circuit is arranged on the circuit layer 132. The control circuit on the circuit layer 132 can also be connected to the first pad 11. Figure 5In this embodiment, the dielectric layer 131 is an insulating layer. The dielectric layer 131 is provided with three layers, and the circuit layer 132 is provided with two layers. The dielectric layer 131 and the circuit layer 132 are alternately stacked in sequence. A conductive member can be arranged in the thickness direction of the substrate 13 to achieve conduction of the control circuits between different layers. In this way, the circuit can be arranged in the thickness direction of the substrate 13, thereby reducing the area of ​​the first side surface 133 and the second side surface 134 of the substrate 13. At the same time, the first solder pads 11 can be arranged more closely, thereby making the lamp beads 2 arranged more closely, thereby improving the picture effect of the LED display screen.

[0056] Based on this, in some embodiments of the present application, a plurality of first pads 11 are provided on the LED circuit board 1, and the plurality of first pads 11 are arranged at intervals, and the first reinforcement layer 1351 is a metal layer, and the first reinforcement layer 1351 is connected to the control circuit on the circuit layer 132. The first reinforcement layer 1351 is set as a metal layer, and the first reinforcement layer 1351 can electrically connect the first pad 11 with the control circuit of the circuit layer 132, that is, the first reinforcement layer 1351 can act as a conductive member, which helps to simplify the structure of the LED circuit board 1 and reduce the production cost of the LED circuit board 1.

[0057] Exemplarily, the first reinforcement layer 1351 and the main layer 111 of the first pad 11 can be made of the same material. In this embodiment, the first reinforcement layer 1351 and the main layer 111 are both made of copper. Furthermore, the first reinforcement layer 1351 is a copper-plated layer. Of course, the material of the second reinforcement layer 1352 and the material of the first reinforcement layer 1351 can also be the same. Exemplarily, the material of the second reinforcement layer 1352 and the material of the first reinforcement layer 1351 are both copper.

[0058] In some embodiments, a second reinforcement layer 1352 is disposed on a side of the substrate 13 away from the first pad 11 (i.e., the second side 134 of the substrate 13), the first reinforcement layer 1351 is connected to the second reinforcement layer 1352, and the first hole 135 passes through the second reinforcement layer 1352, and the second reinforcement layer 1352 is located between the first insulating layer 15 and the substrate 13. Since the first reinforcement layer 1351 and the second reinforcement layer 1352 are both made of copper, and the first reinforcement layer 1351 can electrically connect the first pad 11 with the control circuit of the circuit layer 132, then the second reinforcement layer 1352 can also be charged, and the second reinforcement layer 1352 is disposed between the first insulating layer 15 and the substrate 13, and the first insulating layer 15 can cover the second reinforcement layer 1352, so that the second reinforcement layer 1352 is separated from the outside, so as to prevent the second reinforcement layer 1352 from contacting with external conductive components and causing a short circuit.

[0059] Reference Figure 2 and Figure 4A second hole 136 is also provided on the substrate 13, and the second hole 136 passes through all the dielectric layers 131 and the circuit layer 132. A first connection layer 1361 is provided on the hole wall of the second hole 136. A second connection layer 1362 and a third connection layer 1363 are provided on the first side surface 133 and the second side surface 134 of the substrate 13. Both ends of the first connection layer 1361 are connected to the second connection layer 1362 and the third connection layer 1363 respectively, wherein the first connection layer 1361, the second connection layer 1362 and the third connection layer 1363 are all metal layers. Exemplarily, the first connection layer 1361, the second connection layer 1362 and the third connection layer 1363 are made of copper.

[0060] Optionally, the first connection layer 1361 can be connected to the control circuit on the circuit layer 132, the second connection layer 1362 can be connected to the control circuit on the first side 133 of the substrate 13, and the third connection layer 1363 can be connected to the control circuit on the second side 134 of the substrate 13, that is, the first connection layer 1361, the second connection layer 1362 and the third connection layer 1363 can act as conductive parts to conduct the control circuits between different layers.

[0061] Different from the first hole 135, the second hole 136 and the first pad 11 are spaced apart. On the one hand, the first connection layer 1361, the second connection layer 1362 and the third connection layer 1363 as a whole penetrate the substrate 13 like a rivet, which can fix the substrate 13 and improve the stability of the connection between the dielectric layer 131 and the circuit layer 132 in the substrate 13. On the other hand, the first connection layer 1361, the second connection layer 1362 and the third connection layer 1363 can realize the electrical conduction of the control circuits between different layers.

[0062] The size of the second hole 136 may be the same as or different from that of the first hole 135 . In the present embodiment, the size of the second hole 136 is the same as that of the first hole 135 , which is 0.2 mm.

[0063] When solder resist ink is applied to the first side surface 133 and the second side surface 134 of the substrate 13 , the solder resist ink may also enter the second hole 136 to fill the second hole 136 .

[0064] Reference Figure 5 and Figure 7 The third reinforcement layer 14 is also provided on the side of the substrate 13 where the first pad 11 is provided. The third reinforcement layer 14 is provided at the edge of the first pad 11, and the third reinforcement layer 14 is connected to the edge of the main layer 111 of the first pad 11. By providing the third reinforcement layer 14, the third reinforcement layer 14 is equivalent to the extension of the first pad 11, and the connection area between the first pad 11 and the substrate 13 can be further increased, and the connection stability between the first pad 11 and the substrate 13 can be further improved.

[0065] Optionally, the main body layer 111 of the first solder pad 11 and the third reinforcement layer 14 are integrally formed, which can improve the connection stability between the first solder pad 11 and the third reinforcement layer 14 .

[0066] In this embodiment, a complete copper layer is firstly provided on the first side 133 and the second side 134 of the substrate 13, and then the copper layer is etched, so that the main layer 111 of the first pads 11, the third reinforcement layers 14 and the second connection layers 1362 are obtained on the first side 133 of the substrate 13, and the second reinforcement layers 1352 and the third connection layers 1363 are obtained on the second side 134 of the substrate 13. Then, the main layer 111 of the first pad 11 and the third reinforcement layer 14 are integrally formed, which can reduce the processing steps and reduce the difficulty of the operation.

[0067] In this embodiment, the second insulating layer 16 covers the third reinforcement layer 14 .

[0068] It should be noted that the design of the second hole 136, the first connection layer 1361, the second connection layer 1362 and the third connection layer 1363 is the prior art, and the second hole 136 is the via hole on the LED circuit board 1; it can be understood that the first hole 135 and the first reinforcement layer 1351 can electrically connect the first pad 11 with the control circuit on the circuit layer 132. Compared with the prior art, the present application can reduce the number of second holes 136 accordingly. Then, when the size of the substrate 13 remains unchanged, in one embodiment, the number of control circuits on the first side 133 of the substrate 13 can be reduced, and the area of ​​the third reinforcement layer 14 can be increased to further improve the stability of the connection between the first pad 11 and the substrate 13. In another embodiment, The area of ​​the third reinforcement layer 14 is properly controlled to increase the number of control circuits on the first side 133. For example, in conventional designs, three control circuits can be arranged between each column of lamp beads 2 on the first side 133 of the substrate 13. In the present embodiment, since the number of second holes 136 is reduced, the first side 133 has more spare positions, and four control circuits can be arranged between each column of lamp beads 2. The number of lamp beads 2 on the entire board is calculated as 80 points * 40 points. One more control circuit can be arranged next to each column of lamp beads 2. Theoretically, seventy-nine more control circuits can be arranged on the entire board, which is conducive to improving the design completion of the LED circuit board 1. If the extra control circuit is used for grounding signals, the signal integrity and EMC (Electro Magnetic Compatibility) of the product can be effectively improved.

[0069] Figure 8 is a partial schematic diagram of the LED circuit board 1, specifically a schematic diagram of the lower left corner area of ​​the LED circuit board 1, refer to Figure 8The LED circuit board 1 has a plurality of pads, which are arranged on the substrate 13 at intervals. The pads located at the edge of the substrate 13 are the first pads 11, and the pads far from the edge of the substrate 13 and close to the center of the substrate 13 are the second pads 12. The second pads 12 are not provided with the first holes 135. It can be understood that the provision of the first holes 135 and the first reinforcement layer 1351 in the first holes 135 will increase the processing cost of the LED circuit board 1. During the handling process, the possibility of the pads located at the edge of the LED circuit board 1 being hit is much greater than that of the pads located at the center of the substrate 13. Therefore, only the first pads 11 located at the edge of the substrate 13 are reinforced, which is conducive to controlling the cost of the LED circuit board 1.

[0070] Reference Figure 2 , Figure 4 and Figure 6 The second side surface 134 of the substrate 13 is also provided with a third pad 17. The third pad 17 can be electrically connected with the control circuit in the corresponding layer as needed. The third pad 17 is used to connect the IC chip 3 (integrated circuit). The IC chip 3 is electrically connected with all the lamp beads 2 through the control circuit, thereby realizing the control of the lamp beads 2.

[0071] In this embodiment, the process requirements of the LED circuit board 1 are as follows:

[0072]

[0073] This embodiment also provides an LED display screen, comprising an LED box, lamp beads 2, and the LED circuit board 1 in any of the above embodiments, wherein the lamp beads 2 are welded on the first pads 11 of the LED circuit board 1, and the LED circuit board 1 is arranged in the LED box. Since the connection stability between the first pads 11 on the LED circuit board 1 and the substrate 13 is high, the first pads 11 are not easy to fall off after being hit, and therefore, the LED display screen including the LED circuit board 1 has good quality and low maintenance cost.

[0074] The LED display screen in this embodiment may be a conventional LED display screen or a small-pitch LED display screen, for example, a miniLED display screen, a MicroLED display screen (Micro Light Emitting Diode Display) or an OLED display screen.

[0075] Optionally, in the present embodiment, after the lamp beads 2 and the LED circuit board 1 are welded, the lamp beads 2 at the edge of the LED circuit board 1 can be glued and reinforced by glue dispensing equipment. Specifically, a single-component, fast-curing modified epoxy adhesive is used for glue dispensing. The cured adhesive layer is respectively bonded to the bottom of the lamp beads 2 and the LED circuit board 1, which increases the bonding force of the LED circuit board 1 to the lamp beads 2 and reduces the risk of the lamp beads 2 being knocked off. Of course, in other embodiments, the lamp beads 2 and the LED circuit board 1 may not be reinforced by epoxy glue dispensing, which can control the production cost of the LED display screen. Even if a collision occurs, only the lamp beads 2 will fall off, and the first solder pad 11 will not fall off. In this case, the lamp beads 2 can be added to the corresponding positions.

[0076] In this embodiment, the LED display screen also has an IC chip 3, which is connected to the third solder pad 17 of the LED circuit board 1. The IC chip 3 is connected to all the lamp beads 2 through a control circuit. The IC chip 3 can control the startup, shutdown and brightness adjustment of the lamp beads 2.

[0077] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An LED circuit board, comprising a substrate and a first soldering pad, wherein the first soldering pad is arranged on a side surface of the substrate, characterized in that: A welding area is provided on a side of the first welding pad away from the substrate, and a first hole is provided on the LED circuit board. The first hole is located in the welding area, and the first hole penetrates the first welding pad and at least partially extends into the substrate along the thickness direction of the substrate. A first reinforcement layer is provided on the inner wall of the first hole, and the first reinforcement layer is connected to the first welding pad.

2. The LED circuit board according to claim 1, characterized in that: The first hole passes through the substrate, and the LED circuit board further includes an insulating filler, which is filled in the first hole and is spaced apart from the first solder pad.

3. The LED circuit board according to claim 2, characterized in that: A first insulating layer is disposed on a side of the substrate away from the first pad, and the first insulating layer extends toward the center of the first hole to form the insulating filling member.

4. The LED circuit board according to claim 1, characterized in that: The first hole passes through the substrate, a second reinforcement layer is disposed on a side of the substrate away from the first pad, and the first reinforcement layer is connected to the second reinforcement layer.

5. The LED circuit board according to claim 4, characterized in that: The first hole penetrates the second reinforcement layer.

6. The LED circuit board according to any one of claims 1 to 5, characterized in that: The first pad includes a main layer and a protective layer, the main layer is arranged between the protective layer and the substrate, and the protective layer is an OSP protective layer or an immersion gold protective layer.

7. The LED circuit board according to any one of claims 1 to 5, characterized in that: The substrate comprises a dielectric layer and a circuit layer, the first reinforcement layer is a metal layer, and the first reinforcement layer is connected to the control circuit on the circuit layer.

8. The LED circuit board according to any one of claims 1 to 5, characterized in that: A third reinforcement layer is also disposed on the side of the substrate where the first pad is disposed. The third reinforcement layer is disposed at the edge of the first pad and is connected to the first pad.

9. The LED circuit board according to claim 8, characterized in that: The first pad and the third reinforcement layer are integrally formed.

10. An LED display screen, comprising lamp beads, characterized in that: It also includes the LED circuit board according to any one of claims 1 to 9, wherein the lamp bead is welded on the first soldering pad of the LED circuit board.

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