COB display module and manufacturing method thereof

Abstract

The invention discloses a COB display module, which comprises a circuit substrate, the circuit substrate is provided with a light-emitting surface, the light-emitting surface is provided with a plurality of bonding pad parts, and each bonding pad part is electrically connected with a light-emitting chip to form a plurality of pixel units; the light emitting surface is further provided with a plurality of concave grooves which are concave inwards, a driving chip is arranged in each concave groove, the upper surface of each driving chip does not protrude out of the corresponding concave groove, and the driving chips are electrically connected with the pixel units so that one driving chip can correspondingly drive one or more pixel units. The bonding pad part and the concave groove are simultaneously arranged on the light-emitting surface of the circuit substrate, the driving chip is arranged in the concave groove, and the bonding pad part and the driving circuit are arranged on the same surface, so that wiring is simpler.

Description

Technical Field

[0001] This invention relates to the field of LED displays, and particularly to a COB display module and its manufacturing method. Background Technology

[0002] In existing COB display modules, the light-emitting chips and driver chips are usually located on opposite sides of the circuit board. This is because if the driver chip is located on the same surface as the light-emitting chip, it will block the light emitted by the light-emitting chip, affecting the light mixing between the light-emitting chips and the light emission angle, thus leading to poor display quality. Moreover, since the LED chips and light-emitting chips are distributed on opposite sides of the circuit board, the wiring is more complex. Summary of the Invention

[0003] The purpose of this invention is to provide a COB display module and its manufacturing method to solve the problems of complex wiring and low refresh rate in existing COB display modules.

[0004] To achieve the above objectives, the present invention provides a COB display module, comprising a circuit board having a light-emitting surface, wherein a plurality of pad portions are provided on the light-emitting surface, and a light-emitting chip is electrically connected to each pad portion to form a plurality of pixel units; the light-emitting surface is also provided with a plurality of inwardly recessed grooves, and a driving chip is provided in each groove, wherein the upper surface of the driving chip does not protrude from the groove, and the driving chip is electrically connected to the pixel units so that one driving chip drives one or more pixel units respectively.

[0005] Preferably, the recessed grooves are configured in a one-to-one correspondence with the pads so that one driver chip drives one pixel unit; or, each recessed groove is configured to correspond to at least two pads so that one driver chip drives at least two pixel units.

[0006] Preferably, a plurality of the pad portions are arranged in an array, and a plurality of the recessed grooves are provided on the same side of the pad portions, and the recessed grooves on one side of the same column of the pad portions are interconnected to form a through groove.

[0007] Preferably, the light-emitting chip includes at least a first light-emitting chip, a second light-emitting chip, and a third light-emitting chip; the pad portion includes a first pad and a second pad; one of the first pad and the second pad is electrically connected to a positive electrode; the other of the first pad and the second pad is electrically connected to a negative electrode; the first pad includes at least a first sub-pad, a second sub-pad, and a third sub-pad; the second pad includes at least a fourth sub-pad, a fifth sub-pad, and a sixth sub-pad; the first sub-pad and the fourth sub-pad are spaced apart, and the first light-emitting chip is soldered onto the first sub-pad and the fourth sub-pad; the second sub-pad and the fifth sub-pad are spaced apart, and the second light-emitting chip is soldered onto the second sub-pad and the fifth sub-pad; the third sub-pad and the sixth sub-pad are spaced apart, and the third light-emitting chip is soldered onto the third sub-pad and the sixth sub-pad; a driving circuit is provided in the recessed groove, and the driving chip is soldered onto the driving circuit; one of the first pad and the second pad is electrically connected to the corresponding driving circuit.

[0008] Preferably, the first, second, and third sub-pads are arranged longitudinally at intervals, and the fourth, fifth, and sixth sub-pads are also arranged longitudinally at intervals. The first, fourth, second, fifth, third, and sixth sub-pads are all arranged laterally at intervals. The upper edge of the first sub-pad in the longitudinal direction is flush with the upper edge of the fourth sub-pad in the longitudinal direction, and the width of the first sub-pad in the longitudinal direction is the same as the width of the fourth sub-pad in the longitudinal direction. The upper edge of the second sub-pad in the longitudinal direction is flush with the upper edge of the fifth sub-pad in the longitudinal direction, and the width of the second sub-pad in the longitudinal direction is the same as the upper edge of the fourth sub-pad in the longitudinal direction. The fifth sub-pad has the same width in the longitudinal direction; the upper edge of the third sub-pad in the longitudinal direction is flush with the upper edge of the sixth sub-pad in the longitudinal direction, and the width of the third sub-pad in the longitudinal direction is the same as that of the sixth sub-pad in the longitudinal direction; the second pad is electrically connected to the corresponding drive line; the first sub-pad has a first extension line extending outward from the side away from the fourth sub-pad, and the first extension line has the same width as the first sub-pad; the second sub-pad has a second extension line extending outward from the side away from the fifth sub-pad, and the second extension line has the same width as the second sub-pad; the third sub-pad has a third extension line extending outward from the side away from the sixth sub-pad, and the third extension line has the same width as the third sub-pad.

[0009] Preferably, the first extension line, the second extension line, and the third extension line are interconnected by a first connecting line to form a common electrode, and a first electrical connection via is provided on the first connecting line; or, a first electrical connection line is connected below the first extension line, the first electrical connection line is located in the region between the first extension line and the second extension line and extends towards the fourth sub-pad; a second electrical connection line is connected below the second extension line, the second electrical connection line is located in the region between the second extension line and the third extension line and extends towards the fifth sub-pad; a third electrical connection line is connected below the third extension line, the third electrical connection line is located in the region between the third extension line and the first extension line in the adjacent pixel unit and extends towards the sixth sub-pad.

[0010] Preferably, the fourth sub-pad has a fourth extension line extending outward from the side away from the first sub-pad, and the fourth extension line has the same width as the fourth sub-pad. The fifth sub-pad has a fifth extension line extending outward from the side away from the second sub-pad, and the fifth extension line has the same width as the fifth sub-pad. The sixth sub-pad has a sixth extension line extending outward from the side away from the third sub-pad, and the sixth extension line has the same width as the sixth sub-pad. The fourth extension line, the fifth extension line, and the sixth extension line are all electrically connected to the drive circuit.

[0011] Preferably, the fourth sub-pad has a second electrical connection via in its center, the fifth sub-pad has a third electrical connection via in its center, and the sixth sub-pad has a fourth electrical connection via in its center; the second, third, and fourth electrical connection vias are used for electrical connection to the positive or negative electrode. Alternatively, the fourth extension line has a fifth electrical connection via, the fifth extension line has a sixth electrical connection via, and the sixth extension line has a seventh electrical connection via; the fifth, sixth, and seventh electrical connection vias are used for electrical connection to the positive or negative electrode.

[0012] Preferably, a solder resist layer is provided between the first pad and the second pad, and the upper surface of the solder resist layer is lower than the upper surface of the first pad or the second pad.

[0013] The present invention also provides a method for manufacturing a COB display module, comprising the following steps: providing a circuit substrate having a light-emitting surface, the light-emitting surface having a plurality of pad portions for connecting light-emitting chips; forming a plurality of inwardly recessed grooves on the circuit substrate; arranging driving lines in the recessed grooves, the driving lines being electrically connected to the pad portions; applying solder paste on the plurality of pad portions and the plurality of driving lines, fixing the light-emitting chips on the pad portions to form a plurality of pixel units, and fixing driving chips on the driving lines so that the driving chips are electrically connected to the pixel units so that one driving chip drives one or more pixel units respectively.

[0014] Preferably, the plurality of pads are arranged in an array, and the step of forming a plurality of inwardly recessed grooves on the circuit board includes: forming an inwardly recessed through groove on one side of each row of pads on the circuit board to form interconnected grooves on one side of each row of pads.

[0015] Preferably, the step of applying solder paste to the plurality of solder pads and the plurality of drive lines includes:

[0016] A printed stencil is provided, the printed stencil including a flat plate portion and a recessed portion recessed downward from the flat plate portion, the flat plate portion having a first mesh portion corresponding to the pad portion, and the recessed portion having a second mesh portion corresponding to the drive circuit; the printed stencil is disposed above the circuit board, with the first mesh portion positioned above the pad portion and the second mesh portion embedded in the through slot and positioned above the drive circuit; solder paste is applied to the printed stencil and printed onto the pads and the drive circuit.

[0017] Compared with the prior art, the present invention enables one driver chip to control one or more pixel units by simultaneously setting a pad portion and a recessed groove on the light-emitting surface of the circuit board and setting a driver chip in the recessed groove. The pad portion and the driving line are set on the same surface, making the wiring simpler. Attached Figure Description

[0018] Figure 1 This is a structural diagram of a COB display module according to the first embodiment of the present invention.

[0019] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0020] Figure 3 This is a structural diagram of the COB display module of the second structure in an embodiment of the present invention, taken from one angle.

[0021] Figure 4 for Figure 3 Enlarged view of point B in the middle.

[0022] Figure 5 This is a structural diagram of the COB display module of the second structure in an embodiment of the present invention from another angle.

[0023] Figure 6 This is a structural diagram of a COB display module according to an embodiment of the present invention, showing a second electrical connection via, a third electrical connection via, and a fourth electrical connection via on the second pad. The ink solder resist layer is not shown in the diagram.

[0024] Figure 7 This is a cross-sectional view of a COB display module according to an embodiment of the present invention, showing a second electrical connection via, a third electrical connection via, and a fourth electrical connection via on the second pad. The figure also shows the ink solder resist layer.

[0025] Figure 8 This is a structural diagram of the COB display module of the present invention, in which a fifth electrical connection via, a sixth electrical connection via, and a seventh electrical connection via are provided on the fourth extension line, the fifth extension line, and the sixth extension line. The ink solder resist layer is not shown in the diagram.

[0026] Figure 9 This is a structural diagram of a COB display module according to an embodiment of the present invention, in which a first electrical connection line, a second electrical connection line, and a third electrical connection line are provided on the first extension line, the second extension line, and the third extension line. The ink solder resist layer is not shown in the diagram.

[0027] Figure 10 This is a structural diagram of a solder resist layer disposed between the first pad and the second pad in a COB display module according to an embodiment of the present invention. Detailed Implementation

[0028] To illustrate the technical content, structural features, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0029] like Figures 1 to 10 As shown, this embodiment of the invention discloses a COB display module, including a circuit board 1. The circuit board 1 has a light-emitting surface 11, and a plurality of pad portions 2 are provided on the light-emitting surface 11. Each pad portion 2 is electrically connected to a light-emitting chip to form a plurality of pixel units 300. The light-emitting surface 11 is also provided with a plurality of inwardly recessed grooves 4. Each recessed groove 4 is provided with a driving chip 30. The upper surface of the driving chip 30 does not protrude from the recessed groove 4. The driving chip 30 is electrically connected to the pixel units 300 so that one driving chip 30 drives one or more pixel units 300. Specifically, as shown... Figure 7 As shown, the light-emitting surface 11 of the circuit board 1 is also provided with a solder resist ink layer 10. At least a portion of the solder pad portion 2 is exposed by creating a window in the solder resist ink layer 10. Figures 1 to 2As shown, the recessed grooves 4 can be located on the same side of the pad portion 2, and the number of recessed grooves 4 is the same as the number of pad portions 2. The depth of the recessed grooves 4 is preferably the same as or slightly greater than the thickness of the driver chip 30 so that the driver chip 30 can be embedded in the recessed grooves 4 without protruding from them. This avoids the driver chip 30 blocking light mixing between pixel units 300 and blocking the light emission angle of pixel units 300, which would lead to poor display effects. The driver chip 30 is correspondingly set with the pixel units 300. One driver chip 30 controls one or more pixel units 300 to achieve static driving, which can achieve high refresh rate, high frame rate and high grayscale, and there are no scan lines during shooting.

[0030] The present invention provides a solution by simultaneously providing a pad portion 2 and a recessed groove 4 on the light-emitting surface 1 of the circuit board 1, and by providing a driver chip 30 in the recessed groove 4, so that one driver chip 30 can control one or more pixel units 300, thereby achieving high refresh rate, high frame rate and high grayscale, and no scan lines during shooting. The design is ingenious. Moreover, the pad portion 2 and the driving line 5 are located on the same surface, making the wiring simpler.

[0031] In this embodiment of the invention, the recessed groove 4 and the pad portion 2 are arranged in a one-to-one correspondence so that one driving chip 30 drives one pixel unit 300. Static driving can be achieved by having the driving chip 30 drive one pixel unit 300, which can achieve high refresh rate, high frame rate and high grayscale, and there are no scan lines during shooting.

[0032] In some other specific embodiments of the present invention, each recessed groove 4 is provided corresponding to at least two pad portions 2 so that one driving chip 30 drives at least two pixel units 300. Specifically, the driving chip 30 can be designed with multiple pin outputs to achieve a one-to-one correspondence between at least two pixel units 300 and the driving channel, thus enabling static driving, achieving high refresh rate, high frame rate, and high grayscale, and eliminating scan lines during shooting. Of course, the driving chip 30 can also use existing scan driving methods to control at least two pixel units 300, which can be selected according to actual needs.

[0033] In embodiments of the present invention, such as Figures 3 to 5 As shown, several pad portions 2 are arranged in an array, and multiple recessed grooves 4 are all located on the same side of the pad portions 2. The recessed grooves 4 on the same side of the same row of pad portions 2 are interconnected to form through grooves 40. Specifically, several pad portions 2 are arranged in a matrix along the horizontal and vertical directions, and the recessed grooves 4 are all located on the same side of the pad portions 2. The recessed grooves 4 on the same side are designed to be interconnected through grooves 40, which facilitates the opening of the recessed grooves 4. That is, multiple rows of through grooves 40 can be directly opened to realize the opening of multiple recessed grooves 4. The process is simple and easy to use in actual production.

[0034] Furthermore, such as Figures 1 to 9 As shown, the light-emitting chip includes at least a first light-emitting chip 31, a second light-emitting chip 32, and a third light-emitting chip 33. The pad portion 2 includes a first pad 21 and a second pad 22. One of the first pad 21 and the second pad 22 is electrically connected to the positive terminal, and the other of the first pad 21 and the second pad 22 is electrically connected to the negative terminal. The first pad 21 includes at least a first sub-pad 211, a second sub-pad 212, and a third sub-pad 213. The second pad 22 includes at least a fourth sub-pad 221, a fifth sub-pad 222, and a sixth sub-pad 223. The first sub-pad 211 and the fourth sub-pad 212... The first light-emitting chip 31 is soldered to the first sub-pad 211 and the fourth sub-pad 221, the second sub-pad 212 and the fifth sub-pad 222 are alternately arranged, and the second light-emitting chip 32 is soldered to the second sub-pad 212 and the fifth sub-pad 222, and the third sub-pad 213 and the sixth sub-pad 223 are alternately arranged, and the third light-emitting chip 33 is soldered to the third sub-pad 213 and the sixth sub-pad 223. A driving circuit 5 is provided in the recessed groove 4, and a driving chip 30 is soldered to the driving circuit 5. One of the first pad 21 and the second pad 22 is electrically connected to the corresponding driving circuit 5. Specifically, the first light-emitting chip 31, the second light-emitting chip 32, and the third light-emitting chip 33 can be red LED chips, green LED chips, and blue LED chips, respectively. The first pad 21 and the second pad 22 are connected to the positive and negative terminals, respectively, thereby supplying power to the first light-emitting chip 31, the second light-emitting chip 32, and the third light-emitting chip 33. It should be noted that the light-emitting chip may also include a fourth light-emitting chip, etc., so that the light-emitting chip can be composed of RGGB, RGBW or other forms. In this case, the first pad 21 and the second pad 22 each include at least four sub-pads. The structure and distribution of the newly added sub-pads are the same as the structure and distribution of the sub-pads mentioned above.

[0035] In this embodiment of the invention, the first sub-pad 211, the second sub-pad 212, and the third sub-pad 213 are arranged longitudinally at intervals, and the fourth sub-pad 221, the fifth sub-pad 222, and the sixth sub-pad 223 are arranged longitudinally at intervals. The first sub-pad 211, the fourth sub-pad 221, the second sub-pad 212, the fifth sub-pad 222, the third sub-pad 213, and the sixth sub-pad 223 are all arranged laterally at intervals. The upper edge of the first sub-pad 211 in the longitudinal direction is flush with the upper edge of the fourth sub-pad 221 in the longitudinal direction, and the width of the first sub-pad 211 in the longitudinal direction is the same as the width of the fourth sub-pad 221 in the longitudinal direction. The upper edge of the second sub-pad 212 in the longitudinal direction is flush with the upper edge of the fifth sub-pad 222 in the longitudinal direction, and the width of the second sub-pad 212 in the longitudinal direction is the same as the upper edge of the fourth sub-pad 221 in the longitudinal direction. The five sub-pads 222 have the same width in the longitudinal direction; the upper edge of the third sub-pad 213 in the longitudinal direction is flush with the upper edge of the sixth sub-pad 223 in the longitudinal direction, and the width of the third sub-pad 213 in the longitudinal direction is the same as that of the sixth sub-pad 223 in the longitudinal direction; the second pad 22 is electrically connected to the corresponding drive line 5; the first sub-pad 211 has a first extension line 61 extending outward from the side away from the fourth sub-pad 221, and the first extension line 61 has the same width as the first sub-pad 211; the second sub-pad 212 has a second extension line 62 extending outward from the side away from the fifth sub-pad 222, and the second extension line 62 has the same width as the second sub-pad 212; the third sub-pad 213 has a third extension line 63 extending outward from the side away from the sixth sub-pad 223, and the third extension line 63 has the same width as the third sub-pad 213. Specifically, as shown... Figure 6 , Figure 8 as well as Figure 9 As shown, the widths of the first sub-pad 211, the second sub-pad 212, the third sub-pad 213, the fourth sub-pad 221, the fifth sub-pad 222, the sixth sub-pad 223, the first extension line 61, the second extension line 62, and the third extension line 63 are all the same. By setting the widths to be the same, on the one hand, it is convenient to process and shape the first pad 21 and the second pad 22; on the other hand, it is also convenient to ensure that copper is not leaked even if there is a lateral offset when opening the first pad 21 and the second pad 22, thus ensuring the exposed area of ​​the pads. The design is ingenious.

[0036] In embodiments of the present invention, such as Figure 6 as well as Figure 8 As shown, the first extension line 61, the second extension line 62 and the third extension line 63 are interconnected through the first connecting line 7 to form a common pole. Specifically, the first connecting line 7 is provided with a first electrical connection via 71, which is used to connect the positive pole or the negative pole.

[0037] In some other embodiments of the present invention, such as Figure 9As shown, a first electrical connection line 91 is connected below the first extension line 61. The first electrical connection line 91 is located in the area between the first extension line 61 and the second extension line 62 and extends towards the fourth sub-pad 221. A second electrical connection line 92 is connected below the second extension line 62. The second electrical connection line 92 is located in the area between the second extension line 62 and the third extension line 63 and extends towards the fifth sub-pad 222. A third electrical connection line 93 is connected below the third extension line 63. The third electrical connection line 93 is located in the area between the third extension line 63 and the first extension line 61 in the adjacent pixel unit 300 and extends towards the sixth sub-pad 223. Specifically, by configuring the first electrical connection line 91, the second electrical connection line 92, and the third electrical connection line 93, it is unnecessary to interconnect the first extension line 61, the second extension line 62, and the third extension line 63 to form a common pole, and it is also unnecessary to provide vias for electrical connections on the first extension line 61, the second extension line 62, and the third extension line 63, effectively saving wiring layers. It should be noted that, as... Figure 9 As shown, since an ink solder resist layer 10 is provided on the circuit board 1, in order to open windows on the first pad 21 and the second pad 22 and to avoid short circuits with the first electrical connection line 91, the second electrical connection line 92, and the third electrical connection line 93 when soldering the first light-emitting chip 31, the second light-emitting chip 32, and the third light-emitting chip 33, three windows can be opened respectively, such as... Figure 9 As shown in 20c, 20d and 20e, even if the area with the window is offset laterally, there will be no copper leakage, ensuring the exposed area of ​​the pad.

[0038] In embodiments of the present invention, such as Figure 6 , Figure 8 and Figure 9 As shown, the fourth sub-pad 221 has a fourth extension line 81 extending outward from the side away from the first sub-pad 211. The width of the fourth extension line 81 is the same as that of the fourth sub-pad 221. The fifth sub-pad 222 has a fifth extension line 82 extending outward from the side away from the second sub-pad 212. The width of the fifth extension line 82 is the same as that of the fifth sub-pad 222. The sixth sub-pad 223 has a sixth extension line 83 extending outward from the side away from the third sub-pad 213. The width of the sixth extension line 83 is the same as that of the sixth sub-pad 223. The fourth extension line 81, the fifth extension line 82, and the sixth extension line 83 are all electrically connected to the drive circuit 5.

[0039] Furthermore, such as Figures 6 to 7As shown, the fourth sub-pad 221 has a second electrical connection via 2211 in the middle, the fifth sub-pad 222 has a third electrical connection via 2221 in the middle, and the sixth sub-pad 223 has a fourth electrical connection via 2231 in the middle. The second electrical connection via 2211, the third electrical connection via 2221 and the fourth electrical connection via 2231 are used for electrical connection to the positive or negative electrode. Specifically, a second electrical connection via 2211 can be directly set on the fourth sub-pad 221, a third electrical connection via 2221 can be directly set on the fifth sub-pad 222, and a fourth electrical connection via 2231 can be directly set on the sixth sub-pad 223. This effectively saves circuit space and makes the COB display module structure more compact. When the second, third, and fourth electrical connection vias 2211, 2221, and 2231 are all electrically connected to the positive terminal, the common terminal is electrically connected to the negative terminal. When the second, third, and fourth electrical connection vias 2211, 2221, and 2231 are all electrically connected to the negative terminal, the common terminal is electrically connected to the positive terminal. Additionally, the areas where windows are opened on the first pad 21 and the second pad 22 are as follows: Figure 6 As shown in Figure 20a, even if the area with the window is offset laterally, there will be no copper leakage, thus ensuring the exposed area of ​​the pads.

[0040] Of course, in other embodiments of the present invention, such as Figure 8 As shown, a fifth electrical connection via 811 is provided on the fourth extension line 81, a sixth electrical connection via 821 is provided on the fifth extension line 82, and a seventh electrical connection via 831 is provided on the sixth extension line 83. The fifth, sixth, and seventh electrical connection vias 811, 821, and 831 are used for electrical connection to the positive or negative electrode. That is, the electrical connection vias may not be provided on the pads, thus avoiding the problem of protrusion or depression of the electrical connection vias on the fourth sub-pad 221, fifth sub-pad 222, and sixth sub-pad 223, which could affect the soldering of the first light-emitting chip 31, the second light-emitting chip 32, and the third light-emitting chip 33. Additionally, the areas where windows are opened on the first pad 21 and the second pad 22 are as follows... Figure 8 As shown in Figure 20b, even if the area with the window is offset laterally, there will be no copper leakage, thus ensuring the exposed area of ​​the pads.

[0041] In embodiments of the present invention, such as Figure 10As shown, a solder resist layer 110 is provided between the first pad 21 and the second pad 22, and the upper surface of the solder resist layer 110 is lower than the upper surfaces of the first pad 21 and the second pad 22. Specifically, the solder resist layer 110 is provided between the first sub-pad 211 and the fourth sub-pad 221, between the second sub-pad 212 and the fifth sub-pad 222, and between the third sub-pad 213 and the sixth sub-pad 223, effectively preventing the first pad 21 and the second pad 22 from sticking and short-circuiting during the soldering of the first light-emitting chip 31, the second light-emitting chip 32, and the third light-emitting chip 33. The upper surface of the solder resist layer 110 is lower than the upper surfaces of the first pad 21 and the second pad 22, which also prevents the solder resist layer 110 from being pushed out of the light-emitting chip, resulting in poor soldering.

[0042] This invention also discloses a method for manufacturing a COB display module, which includes the following steps:

[0043] S1. A circuit board 1 is provided. The circuit board 1 has a light-emitting surface 11. The light-emitting surface 11 is provided with a plurality of pads 2. The pads 2 are used to connect light-emitting chips. Specifically, the light-emitting chip may include at least a first light-emitting chip 31, a second light-emitting chip 32 and a third light-emitting chip 33. The first light-emitting chip 31, the second light-emitting chip 32 and the third light-emitting chip 33 may be a red light LED chip, a green light LED chip and a blue light LED chip, respectively. The circuit board 1 is a PCB board. The circuit board 1 can be manufactured by cavity process and has a plurality of pads 2.

[0044] S2. Multiple recessed grooves 4 are formed inwardly on the circuit board 1.

[0045] S3. A drive line 5 is arranged in the recessed groove 4 and electrically connected to the pad portion 2. Specifically, the drive line 5 can be arranged in the recessed groove 4 by printing and electrically connected to the pad portion 2.

[0046] S4. Solder paste is applied to several pad portions 2 and multiple drive lines 5, and a first light-emitting chip 31, a second light-emitting chip 32, and a third light-emitting chip 33 are fixed on the pad portions 2 to form several pixel units 300. A drive chip 30 is fixed on the drive lines 5 so that the drive chip 30 is electrically connected to the pixel unit 300 in a one-to-one correspondence, so that one drive chip 30 drives one or more pixel units 300. Specifically, after the first light-emitting chip 31, the second light-emitting chip 32, and the third light-emitting chip 33 are placed on the pad portions 2 and the drive chip 30 is placed on the drive lines 5, the first light-emitting chip 31, the second light-emitting chip 32, the third light-emitting chip 33, and the drive chip 30 can be soldered and fixed in one reflow soldering process.

[0047] In this embodiment of the invention, a plurality of pads 2 are arranged in an array. Step S2, which involves forming a plurality of inwardly recessed grooves 4 on the circuit board 1, includes:

[0048] S21. An inwardly recessed through-slot 40 is formed on one side of each row of pads 2 on the circuit board 1 to form interconnected recessed slots 4 on one side of each row of pads 2. Specifically, a plurality of pads 2 are arranged in a matrix along the horizontal and vertical directions, and the recessed slots 4 are all located on the same side of the pads 2 and the recessed slots 4 on the same side are designed to be interconnected through-slots 40, which facilitates the opening of the recessed slots 4. That is, multiple recessed slots 4 can be opened by directly opening multiple rows of through-slots 40. The process is simple and also facilitates the stencil printing of solder paste in step S4, making it easy to use in actual production.

[0049] In this embodiment of the invention, step S4, which involves applying solder paste to a plurality of pads 2 and a plurality of drive lines 5, includes:

[0050] S41. A printed stencil is provided, the printed stencil including a flat plate portion and a recessed portion recessed downward from the flat plate portion. A first mesh portion is provided on the flat plate portion corresponding to the pad portion 2, and a second mesh portion is provided on the recessed portion corresponding to the drive line 5. The printed stencil is placed above the circuit board 1, with the first mesh portion located above the pad portion 2 and the second mesh portion embedded in the through groove 40 and located above the drive line 5.

[0051] S41. Solder paste is applied to the printed stencil and printed onto the pads and drive lines 5, thereby achieving the application of solder paste on several pad sections 2 and several drive lines 5.

[0052] The embodiments of the present invention provide that by simultaneously setting a pad portion 2 and multiple rows of through slots 40 on the light-emitting surface 11 of the circuit board 1, and setting a driving chip 30 in the through slots 40, one driving chip 30 can control one or more pixel units 300, and can achieve high refresh rate, high frame rate and high grayscale, and no scan lines when shooting. The process is easy to implement and the design is ingenious.

[0053] The above-disclosed examples are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention shall still fall within the scope of the present invention.

Claims

1. A COB display module, characterized in that, The device includes a circuit board having a light-emitting surface. The light-emitting surface has a plurality of pads, and each pad is electrically connected to a light-emitting chip to form a plurality of pixel units. The light-emitting surface also has a plurality of inwardly recessed grooves, and each groove contains a driving chip. The upper surface of the driving chip does not protrude from the groove. The driving chip is electrically connected to the pixel units so that one driving chip drives one or more pixel units.

2. The COB display module as described in claim 1, characterized in that, The recessed grooves are configured in a one-to-one correspondence with the pads so that one driver chip drives one pixel unit; or, each recessed groove is configured to correspond to at least two pads so that one driver chip drives at least two pixel units.

3. The COB display module as described in claim 1, characterized in that, A plurality of pads are arranged in an array, and multiple recessed grooves are provided on the same side of the pads, and the recessed grooves on one side of the same row of pads are interconnected to form a through groove.

4. The COB display module as described in claim 1, characterized in that, The light-emitting chip includes at least a first light-emitting chip, a second light-emitting chip, and a third light-emitting chip. The pad portion includes a first pad and a second pad. One of the first pad and the second pad is electrically connected to a positive electrode, and the other of the first pad and the second pad is electrically connected to a negative electrode. The first pad includes at least a first sub-pad, a second sub-pad, and a third sub-pad. The second pad includes at least a fourth sub-pad, a fifth sub-pad, and a sixth sub-pad. The first sub-pad and the fourth sub-pad are spaced apart, and the first light-emitting chip is soldered onto the first sub-pad and the fourth sub-pad. The second sub-pad and the fifth sub-pad are spaced apart, and the second light-emitting chip is soldered onto the second sub-pad and the fifth sub-pad. The third sub-pad and the sixth sub-pad are spaced apart, and the third light-emitting chip is soldered onto the third sub-pad and the sixth sub-pad. The recessed groove is provided with a driving circuit, and the driving chip is soldered onto the driving circuit. One of the first pad and the second pad is electrically connected to the corresponding driving circuit.

5. The COB display module as described in claim 4, characterized in that, The first, second, and third sub-pads are arranged longitudinally at intervals, and the fourth, fifth, and sixth sub-pads are also arranged longitudinally at intervals. The first, fourth, second, fifth, third, and sixth sub-pads are all arranged laterally at intervals. The upper edge of the first sub-pad in the longitudinal direction is flush with the upper edge of the fourth sub-pad in the longitudinal direction, and the width of the first sub-pad in the longitudinal direction is the same as that of the fourth sub-pad in the longitudinal direction. The upper edge of the second sub-pad in the longitudinal direction is flush with the upper edge of the fifth sub-pad in the longitudinal direction, and the width of the second sub-pad in the longitudinal direction is the same as that of the fifth sub-pad in the longitudinal direction. The upper edge of the third sub-pad in the longitudinal direction is flush with the upper edge of the sixth sub-pad in the longitudinal direction, and the width of the third sub-pad in the longitudinal direction is the same as that of the sixth sub-pad in the longitudinal direction. The second pad is electrically connected to the corresponding drive line. The first sub-pad has a first extension line extending outward from the side away from the fourth sub-pad. The first extension line has the same width as the first sub-pad. The second sub-pad has a second extension line extending outward from the side away from the fifth sub-pad. The second extension line has the same width as the second sub-pad. The third sub-pad has a third extension line extending outward from the side away from the sixth sub-pad. The third extension line has the same width as the third sub-pad.

6. The COB display module as described in claim 5, characterized in that, The first extension line, the second extension line, and the third extension line are interconnected by a first connecting line to form a common electrode, and the first connecting line is provided with a first electrical connection via; or, A first electrical connection line is connected below the first extension line. The first electrical connection line is located in the region between the first extension line and the second extension line and extends towards the fourth sub-pad. A second electrical connection line is connected below the second extension line. The second electrical connection line is located in the region between the second extension line and the third extension line and extends towards the fifth sub-pad. A third electrical connection line is connected below the third extension line. The third electrical connection line is located in the region between the third extension line and the first extension line in the adjacent pixel unit and extends towards the sixth sub-pad.

7. The COB display module as described in claim 5, characterized in that, The fourth sub-pad has a fourth extension line extending outward from the side away from the first sub-pad, and the width of the fourth extension line is the same as that of the fourth sub-pad. The fifth sub-pad has a fifth extension line extending outward from the side away from the second sub-pad, and the width of the fifth extension line is the same as that of the fifth sub-pad. The sixth sub-pad has a sixth extension line extending outward from the side away from the third sub-pad, and the width of the sixth extension line is the same as that of the sixth sub-pad. The fourth extension line, the fifth extension line, and the sixth extension line are all electrically connected to the drive circuit.

8. The COB display module as described in claim 7, characterized in that, The fourth sub-pad has a second electrical connection via in its center, the fifth sub-pad has a third electrical connection via in its center, and the sixth sub-pad has a fourth electrical connection via in its center. The second, third, and fourth electrical connection vias are used for electrical connection to the positive or negative electrode; or... The fourth extension line is provided with a fifth electrical connection via, the fifth extension line is provided with a sixth electrical connection via, and the sixth extension line is provided with a seventh electrical connection via. The fifth electrical connection via, the sixth electrical connection via, and the seventh electrical connection via are used for electrical connection to the positive or negative electrode.

9. The COB display module as described in claim 4, characterized in that, A solder resist layer is provided between the first pad and the second pad, and the upper surface of the solder resist layer is lower than the upper surface of the first pad or the second pad.

10. A method for manufacturing a COB display module, characterized in that, Includes the following steps: A circuit board is provided, the circuit board having a light-emitting surface, and the light-emitting surface having a plurality of pad portions for connecting light-emitting chips; Multiple inwardly recessed grooves are formed in the circuit board. A drive circuit is arranged in the recessed groove, and the drive circuit is electrically connected to the pad portion; Solder paste is applied to several of the said pad portions and multiple said driving lines, and the light-emitting chip is fixed on the pad portions to form a plurality of pixel units. A driving chip is fixed on the driving lines so that the driving chip is electrically connected to the pixel unit so that one driving chip drives one or more of the pixel units.

11. The method for manufacturing a COB display module as described in claim 10, characterized in that, The step of forming multiple inwardly recessed grooves on the circuit board by arranging a plurality of pads in an array includes: An inwardly recessed through groove is formed on one side of each row of pads on the circuit board to form interconnected recessed grooves on one side of each row of pads.

12. The method for manufacturing a COB display module as described in claim 11, characterized in that, The step of applying solder paste on the plurality of said pads and the plurality of said drive lines includes: A printed stencil is provided, the printed stencil including a flat plate portion and a recessed portion recessed downward from the flat plate portion, the flat plate portion having a first mesh portion corresponding to the pad portion, and the recessed portion having a second mesh portion corresponding to the drive circuit; the printed stencil is disposed above the circuit board, with the first mesh portion positioned above the pad portion and the second mesh portion embedded in the through slot and positioned above the drive circuit; Solder paste is applied to the printed stencil and printed onto the pads and the drive circuitry.

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