Circuit board, circuit board manufacturing method and LED packaging board

Abstract

The present application relates to the technical field of printed circuit boards, and provides a circuit board, a circuit board manufacturing method and an LED packaging board. The circuit board manufacturing method includes providing a substrate, on which a reference pad is arranged, and the reference pad includes a first pad, a second pad and a third pad that are connected in sequence; processing the reference pad so that the height of the surface of the first pad facing away from the substrate is less than the height of the surface of the second pad facing away from the substrate, or forming a blocking portion on the surface of the reference pad facing away from the substrate, wherein the blocking portion is located at the connection between the first pad and the second pad. The circuit board manufacturing method of the present application can, while ensuring a small distance between each LED chip, avoid the displacement of the die bonding position of the LED chip during the dispensing process, and improve the die bonding and packaging yield.

Description

Technical Field

[0001] This application relates to the technical field of printed circuit boards, and particularly to a circuit board, a method for manufacturing a circuit board, and an LED packaging board. Background Art

[0002] Mini LED (light-emitting diode) can be divided into two types according to the wafer packaging method: front-mounted and flip-chip, and can be divided into two types according to the light source: backlight and direct display RGB. The packaging process of front-mounted direct display mini LED includes processes such as dispensing, die bonding, wire bonding, and encapsulation. The dispensing process is to fix the LED wafer on the solder pad of the circuit board. Conductive silver glue is used for the red (R) wafer, and non-conductive white glue is used for the green (G) wafer and the blue (B) wafer.

[0003] In some product designs, in order to further improve the resolution of Mini LED, it is necessary to reduce the pixel pitch, that is, to reduce the distance between each LED wafer. However, this will also cause the die bonding position of the LED wafer to shift during the dispensing process, resulting in a low die bonding and encapsulation yield. Summary of the Invention

[0004] This application provides a circuit board, a method for manufacturing a circuit board, and an LED packaging board to avoid the die bonding position of the LED wafer from shifting during the dispensing process and improve the die bonding and encapsulation yield while ensuring a small distance between each LED wafer.

[0005] An embodiment of the first aspect of this application provides a method for manufacturing a circuit board, including:

[0006] Providing a substrate, on which a reference solder pad is provided, and the reference solder pad includes a first solder pad, a second solder pad, and a third solder pad that are connected in sequence;

[0007] Processing the reference solder pad so that the height of the surface of the first solder pad facing away from the substrate is less than the height of the surface of the second solder pad facing away from the substrate or forming a blocking portion on the surface of the reference solder pad facing away from the substrate, where the blocking portion is located at the connection between the first solder pad and the second solder pad.

[0008] In some of these embodiments, processing the reference solder pad so that the height of the surface of the first solder pad facing away from the substrate is less than the height of the surface of the second solder pad facing away from the substrate specifically includes: thinning the first solder pad so that the height of the remaining surface of the first solder pad facing away from the substrate is less than the height of the surface of the second solder pad facing away from the substrate.

[0009] In some of these embodiments, the first solder pad is thinned by means of etching, mechanical milling, or laser ablation.

[0010] In some of these embodiments, the reference pad is processed such that the height of the surface of the first pad facing away from the substrate is less than the height of the surface of the second pad facing away from the substrate. Specifically, it includes: thickening the second pad such that the height of the surface of the first pad facing away from the substrate is less than the height of the thickened second pad facing away from the substrate.

[0011] In some of these embodiments, the second pad is thickened by electroplating.

[0012] In some of these embodiments, the reference pad is processed such that a blocking portion is formed on the surface of the reference pad facing away from the substrate. Specifically, it includes: forming a blocking portion on the surface of the reference pad facing away from the substrate by electroplating or solder mask, and the blocking portion is a copper dam or a solder mask bridge.

[0013] In some of these embodiments, the width of the blocking portion is 75 μm - 150 μm.

[0014] In some of these embodiments, the height of the blocking portion is 12 μm - 18 μm.

[0015] Embodiments of the second aspect of the present application provide a circuit board, including a substrate, on which a reference pad is provided. The reference pad includes a first pad, a second pad, and a third pad connected in sequence. The height of the surface of the first pad facing away from the substrate is less than the height of the surface of the second pad facing away from the substrate; or,

[0016] a blocking portion is provided on the surface of the reference pad facing away from the substrate, and the blocking portion is located at the connection between the first pad and the second pad.

[0017] Embodiments of the third aspect of the present application provide an LED packaging board, including a first chip, a second chip, a third chip, and the circuit board as described in the second aspect. The first chip is bonded to the first pad by a conductive adhesive, and the second chip and the third chip are respectively bonded to the second pad and the third pad by non-conductive adhesives.

[0018] The circuit board manufacturing method provided by the embodiments of the present application has the beneficial effects that: since the reference pads on the substrate include a first pad, a second pad, and a third pad that are connected in sequence, and the height of the surface of the first pad facing away from the substrate is less than the height of the surface of the second pad facing away from the substrate, or a blocking portion is provided on the surface of the reference pad facing away from the substrate at the connection between the first pad and the second pad, it can not only ensure that the distances between the first pad, the second pad, and the third pad are small, so that the distances between the LED chips are small and the pixel pitch is small, but also avoid the conductive glue on the first pad and the non-conductive glue on the second pad from attracting and pulling each other when bonding the chips on the first pad, the second pad, and the third pad in the subsequent dispensing process, resulting in the shift of the die bonding position of the LED chips, thereby improving the die bonding and encapsulation yield.

[0019] The beneficial effects of the circuit board provided by the present application compared with the prior art and the beneficial effects of the LED packaging board provided by the present application compared with the prior art are both the same as the beneficial effects of the circuit board manufacturing method provided by the present application compared with the prior art, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0021] Figure 1 is a flowchart of the circuit board manufacturing method in one embodiment of the present application;

[0022] Figure 2 is a schematic structural diagram of the LED packaging board in one embodiment of the present application;

[0023] Figure 3 is a flowchart of the circuit board manufacturing method in another embodiment of the present application;

[0024] Figure 4 is a schematic structural diagram of the LED packaging board in another embodiment of the present application.

[0025] The meanings of the marks in the figure are as follows:

[0026] 100. LED packaging board; 10. Substrate; 11. First pad; 12. Second pad; 13. Third pad; 14. Fourth pad; 15. Fifth pad; 16. Sixth pad; 17. Seventh pad; 20. Blocking portion; 30. First chip; 40. Second chip; 50. Third chip. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be 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.

[0028] 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.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality of" means two or more, unless otherwise specifically defined.

[0030] Reference to "an embodiment", "some embodiments" or "the embodiments" in the description of the present application means that a specific feature, structure or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, statements such as "in an embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments" etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all of the embodiments", unless otherwise specifically emphasized in other ways. In addition, in one or more embodiments, specific features, structures or characteristics can be combined in any suitable manner.

[0031] In order to illustrate the technical solution of the present application, the following will be described in conjunction with specific drawings and embodiments.

[0032] Please refer to Figure 1 and Figure 2 , embodiments of the first aspect of the present application provide a method for manufacturing a circuit board, including:

[0033] S10: Provide a substrate 10, on which a reference pad is provided, and the reference pad includes a first pad 11, a second pad 12 and a third pad 13 that are connected in sequence.

[0034] Specifically, the first pad 11, the second pad 12 and the third pad 13 can be integrally formed, and the spacing between the first pad 11, the second pad 12 and the third pad 13 is small, so that the LED pixel pitch can be small.

[0035] It can be understood that at this time, the surfaces of the first pad 11 facing away from the substrate 10, the second pad 12 facing away from the substrate 10, and the third pad 13 facing away from the substrate 10 can be located on the same plane.

[0036] It can be understood that the first pad 11 can be used to mount the first chip 30, that is, a red light (R) chip, the second pad 12 can be used to mount the second chip 40, that is, a green light (G) chip, and the third pad 13 can be used to mount the third chip 50, that is, a blue light (B) chip. Among them, the first chip 30 is bonded to the first pad 11 through a conductive adhesive, and the second chip 40 and the third chip 50 are respectively bonded to the second pad 12 and the third pad 13 through non-conductive adhesives.

[0037] S20: Process the reference pads so that the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10.

[0038] Specifically, after processing the reference pads, when the substrate 10 is placed horizontally with the reference pads facing upward, the surface of the first pad 11 facing away from the substrate 10 is lower than the surface of the second pad 12 facing away from the substrate 10, so as to limit the diffusion range of the conductive adhesive on the first pad 11 and prevent the conductive adhesive on the first pad 11 and the non-conductive adhesive on the second pad 12 from being adsorbed and pulled together, resulting in the misalignment of the die bonding position of the LED chip.

[0039] Optionally, the surface of the first pad 11 facing away from the substrate 10 is lower than the surface of the third pad 13 facing away from the substrate 10.

[0040] In the circuit board manufacturing method provided by the embodiments of the present application, since the reference pads on the substrate 10 include a first pad 11, a second pad 12, and a third pad 13 connected in sequence, and the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10, it can not only ensure a small distance between the first pad 11, the second pad 12, and the third pad 13, so that the distance between the LED chips is small and the pixel pitch is small, but also avoid the conductive adhesive on the first pad 11 and the non-conductive adhesive on the second pad 12 from being adsorbed and pulled together when bonding the chips on the first pad 11, the second pad 12, and the third pad 13 in the subsequent dispensing process, resulting in the misalignment of the die bonding position of the LED chip, thereby improving the die bonding encapsulation yield.

[0041] Please refer to Figure 2 , process the reference pads so that the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10, specifically including: thinning the first pad 11 so that the height of the remaining surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10.

[0042] By adopting the above solution, it is convenient to process the first pad 11, so that the height of the surface of the remaining first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10, so as to limit the diffusion range of the conductive adhesive on the first pad 11 and avoid the mutual adsorption and traction between the conductive adhesive on the first pad 11 and the non-conductive adhesive on the second pad 12.

[0043] Optionally, the first pad 11 is thinned by means of etching, mechanical milling or laser ablation.

[0044] For example, in one embodiment, the first pad 11 is thinned by etching, which specifically includes:

[0045] First, film pasting: Use a vacuum laminating machine to paste the photosensitive dry film to ensure that the dry film is completely attached to the board surface of the substrate 10 close to the reference pad.

[0046] Secondly, exposure: Only the dry film in the area where the first pad 11 is located does not need to be exposed, and the dry film in the remaining areas is exposed. The width of the area that does not need to be exposed is 25 μm larger than the width of the first pad 11 on one side to prevent alignment deviation, and the length is determined according to the design. Unit segmentation exposure is adopted to ensure the exposure alignment accuracy.

[0047] Then, development: Remove the unexposed and cured dry film to expose the area corresponding to the area to be etched and thinned.

[0048] Finally, micro-etching: Use micro-etching solution to etch the area corresponding to the area to be etched and thinned, and control the etching depth specification to be 3 μm ± 1 μm. After etching, the height of the surface of the first pad 11 facing away from the substrate 10 is reduced, and the conductive adhesive on the first pad 11 cannot spread to other surrounding pads during dotting and die bonding, ensuring the good yield of die bonding and encapsulation.

[0049] It can be understood that the photosensitive dry film can also be replaced with a wet film.

[0050] Please refer to Figure 2 , in some of these embodiments, the reference pad is processed so that the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10, which specifically includes: thickening the second pad 12 so that the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the thickened second pad 12 facing away from the substrate 10.

[0051] By adopting the above scheme, it is convenient to process the second pad 12, so that the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the thickened second pad 12 facing away from the substrate 10, so as to limit the diffusion range of the conductive adhesive on the first pad 11 and avoid the mutual adsorption and traction between the conductive adhesive on the first pad 11 and the non-conductive adhesive on the second pad 12.

[0052] Optionally, while thickening the second pad 12, the third pad 13 can be thickened together.

[0053] Optionally, the second pad 12 is thickened by electroplating.

[0054] For example, in another embodiment, the second pad 12 is thickened by electroplating, which specifically includes:

[0055] First, film pasting: Use a vacuum laminating machine to paste a dry film to ensure that the dry film completely adheres to the board surface of the substrate 10 close to the reference pad.

[0056] Secondly, exposure: The dry film in the area where the second pad 12 is located and the area where the third pad 13 is located is not exposed, and the dry film in the area where the first pad 11 is located is exposed, and the dry film in this area is cured so that it cannot be removed by the developing solution.

[0057] Then, developing: Remove the unexposed and uncured dry film so that the second pad 12 and the third pad 13 are not covered by the dry film.

[0058] Next, electroplating and thickening: Electroplate and thicken the substrate 10, that is, through the electroplating process, thicken the copper layers of the second pad 12 and the third pad 13 that are not covered by the dry film, so that their heights from the surface of the substrate 10 are greater than the height of the surface of the first pad 11 facing away from the substrate 10, so that the conductive adhesive on the first pad 11 cannot spread to other surrounding pads during dotting and die bonding, ensuring the good yield of die bonding and encapsulation.

[0059] Optionally, electroplating and thickening can be performed before the conventional circuit etching of the substrate 10. At this time, the outer copper layer of the substrate 10 is still integral, which is convenient for electroplating operation.

[0060] Finally, film stripping: After the electroplating and thickening process is completed, strip the dry film on the board surface of the substrate 10, and then carry out the production and processing of the next process.

[0061] Please refer to Figure 3 and Figure 4 , the embodiments of the first aspect of the present application also provide another method for manufacturing a circuit board, including:

[0062] S100: Provide a substrate 10, on which a reference pad is provided, and the reference pad includes a first pad 11, a second pad 12 and a third pad 13 connected in sequence.

[0063] Specifically, the first pad 11, the second pad 12, and the third pad 13 can be integrally formed. The spacing between the first pad 11, the second pad 12, and the third pad 13 is small, so that the LED pixel pitch can be small.

[0064] It can be understood that at this time, the surfaces of the first pad 11 facing away from the substrate 10, the second pad 12 facing away from the substrate 10, and the third pad 13 facing away from the substrate 10 can be located on the same plane.

[0065] It can be understood that the first pad 11 can be used to mount the first chip 30, that is, the red light (R) chip, the second pad 12 can be used to mount the second chip 40, that is, the green light (G) chip, and the third pad 13 can be used to mount the third chip 50, that is, the blue light (B) chip. Among them, the first chip 30 is bonded to the first pad 11 through conductive adhesive, and the second chip 40 and the third chip 50 are respectively bonded to the second pad 12 and the third pad 13 through non-conductive adhesive.

[0066] S200: Process the reference pad so that a blocking portion 20 is formed on the surface of the reference pad facing away from the substrate 10, and the blocking portion 20 is located at the connection between the first pad 11 and the second pad 12.

[0067] Specifically, after processing the reference pad, when the substrate 10 is placed horizontally and the reference pad is placed upward, the surface of the blocking portion 20 facing away from the substrate 10 is higher than the surface of the first pad 11 facing away from the substrate 10 and higher than the surface of the second pad 12 facing away from the substrate 10, so that the blocking portion 20 can limit the diffusion range of the conductive adhesive on the first pad 11 and prevent the conductive adhesive on the first pad 11 and the non-conductive adhesive on the second pad 12 from attracting and pulling each other.

[0068] In the circuit board manufacturing method provided by the embodiment of the present application, since the reference pad on the substrate 10 includes the first pad 11, the second pad 12, and the third pad 13 connected in sequence, and the blocking portion 20 located at the connection between the first pad 11 and the second pad 12 is provided on the surface of the reference pad facing away from the substrate 10, it can not only ensure that the spacing between the first pad 11, the second pad 12, and the third pad 13 is small, so that the pixel pitch is small, but also avoid the conductive adhesive on the first pad 11 and the non-conductive adhesive on the second pad 12 from attracting and pulling each other when bonding the chips on the first pad 11, the second pad 12, and the third pad 13 in the subsequent dispensing process, resulting in the shift of the die bonding position of the LED chip, thereby improving the die bonding and encapsulation yield.

[0069] Please refer to Figure 4, optionally, a blocking portion 20 is formed on the surface of the reference pad facing away from the substrate 10 by electroplating or solder mask, and the blocking portion 20 is a copper dam or a solder mask bridge.

[0070] Optionally, the width of the blocking portion is 75μm - 150μm, such as 75μm, 90μm, 105μm, 120μm, 135μm, and 150μm, etc., and the height is 12μm - 18μm, such as 12μm, 14μm, 16μm, and 18μm, etc. In this way, not only can the conductive adhesive on the first pad 11 be blocked, but also the subsequent die bonding and encapsulation are not affected.

[0071] For example, in another embodiment, the blocking portion 20 is a copper dam, and the blocking portion 20 is provided on the surface of the reference pad facing away from the substrate 10 by electroplating. Specifically, it includes:

[0072] First, film pasting: Use a vacuum laminating machine to paste the dry film to ensure that the dry film completely adheres to the surface of the substrate 10 near the reference pad.

[0073] Secondly, exposure: The dry film at the connection of the first pad 11 and the second pad 12 is not exposed, and the dry film in other areas is exposed and cured so that it cannot be removed by the developing solution.

[0074] Then, developing: Remove the unexposed and uncured dry film so that the connection of the first pad 11 and the second pad 12 is not covered by the dry film.

[0075] Next, electroplating and thickening: Electroplate and thicken the substrate 10, that is, thicken the copper layer at the connection of the first pad 11 and the second pad 12 that is not covered by the dry film through the electroplating process to generate a copper dam. The height of the copper dam is higher than that of the first pad 11 and higher than that of the second pad 12, so that the conductive adhesive on the first pad 11 cannot spread to other surrounding pads during die bonding with adhesive, ensuring the quality yield of die bonding and encapsulation.

[0076] Finally, film stripping: After the electroplating and thickening process is completed, strip the dry film on the surface of the substrate 10 and then proceed with the production and processing of the next process.

[0077] It can be understood that the width of the copper dam cannot affect the size of the reference pad, that is, it does not affect the subsequent die bonding and encapsulation. For example, the width of the copper dam can be set to 75μm - 150μm, such as 75μm, 90μm, 105μm, 120μm, 135μm, and 150μm, etc.

[0078] Optionally, the height of the copper dam can be set to 12μm - 18μm, such as 12μm, 14μm, 16μm, and 18μm, etc. In this way, not only can the conductive adhesive on the first pad 11 be blocked, but also the subsequent die bonding and encapsulation are not affected.

[0079] Optionally, the length of the copper dam does not exceed the width of the reference pad to avoid affecting subsequent die bonding encapsulation.

[0080] For example, in yet another embodiment, the blocking portion 20 is a solder mask bridge, and the blocking portion 20 is provided on the surface of the reference pad facing away from the substrate 10 by means of solder masking, specifically including:

[0081] First, screen printing / spraying: A layer of solder mask ink with a uniform thickness is printed / sprayed on the outer layer of the substrate 10 by means of screen printing / spraying. If screen printing is used, dot mesh printing can be used. Before printing, the design data of the dot mesh is changed, and an ink filling position is added at the position where the solder mask bridge needs to be provided at the connection of the first pad 11 and the second pad 12.

[0082] Second, pre-curing: The substrate 10 printed / sprayed with solder mask ink is pre-cured to reduce the fluidity of the ink.

[0083] Then, exposure: The solder mask ink that needs to be retained on the surface of the substrate 10 is exposed and cured. For this solution, the solder mask ink at the connection of the first pad 11 and the second pad 12 needs to be exposed and cured.

[0084] Next, developing: The unexposed and uncured ink is washed away with developing solution.

[0085] Finally, final curing: The ink remaining on the surface of the substrate 10 is cured at a high temperature to enhance its surface hardness, heat shock resistance and chemical resistance, and a solder mask bridge is obtained.

[0086] It can be understood that in this embodiment, the operation of adding a solder mask bridge at the connection of the first pad 11 and the second pad 12 can be carried out together with the conventional outer layer solder masking to save production time and production cost. Only the screen printing / solder mask exposure data needs to be changed so that the solder mask ink at the preset position of the reference pad is retained to form a solder mask bridge.

[0087] It can be understood that the width of the solder mask bridge cannot affect the size of the reference pad and does not affect subsequent die bonding encapsulation. For example, the width of the solder mask bridge can be set to 75μm - 150μm, such as 75μm, 90μm, 105μm, 120μm, 135μm and 150μm, etc.

[0088] Optionally, the height of the solder mask bridge can be set to 12μm - 18μm, such as 12μm, 14μm, 16μm and 18μm, etc. In this way, not only can the conductive adhesive on the first pad 11 be blocked, but also subsequent die bonding encapsulation is not affected.

[0089] Optionally, the length of the solder mask bridge does not exceed the width of the reference pad to avoid affecting subsequent die bonding encapsulation.

[0090] Please refer to Figure 2 An embodiment of the second aspect of the present application provides a circuit board, including a substrate 10, on which a reference pad is provided. The reference pad includes a first pad 11, a second pad 12, and a third pad 13 connected in sequence. The height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10.

[0091] For the circuit board provided by the embodiment of the present application, since the reference pad on the substrate 10 includes a first pad 11, a second pad 12, and a third pad 13 connected in sequence, and the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10, it can not only ensure that the distance between the first pad 11, the second pad 12, and the third pad 13 is small, so that the distance between each LED chip is small and the pixel pitch is small, but also avoid the conductive glue on the first pad 11 and the non-conductive glue on the second pad 12 from adsorbing and pulling each other when bonding the chips on the first pad 11, the second pad 12, and the third pad 13 in the subsequent dispensing process, resulting in the deviation of the die bonding position of the LED chip, thus improving the die bonding and encapsulation yield.

[0092] Please refer to Figure 4 An embodiment of the second aspect of the present application further provides another circuit board, including a substrate 10, on which a reference pad is provided. The reference pad includes a first pad 11, a second pad 12, and a third pad 13 connected in sequence. A blocking portion 20 is provided on the surface of the reference pad facing away from the substrate 10, and the blocking portion 20 is located at the connection between the first pad 11 and the second pad 12.

[0093] For the circuit board provided by the embodiment of the present application, since the reference pad on the substrate 10 includes a first pad 11, a second pad 12, and a third pad 13 connected in sequence, and a blocking portion 20 located at the connection between the first pad 11 and the second pad 12 is provided on the surface of the reference pad facing away from the substrate 10, it can not only ensure that the distance between the first pad 11, the second pad 12, and the third pad 13 is small, so that the distance between each LED chip is small and the pixel pitch is small, but also avoid the conductive glue on the first pad 11 and the non-conductive glue on the second pad 12 from adsorbing and pulling each other when bonding the chips on the first pad 11, the second pad 12, and the third pad 13 in the subsequent dispensing process, resulting in the deviation of the die bonding position of the LED chip, thereby improving the die bonding and encapsulation yield.

[0094] Please refer to Figure 2 and Figure 4, an embodiment of the third aspect of the present application provides an LED packaging board 100, which includes a first chip 30, a second chip 40, a third chip 50, and a circuit board as in the second aspect. The first chip 30 is bonded to the first pad 11 through a conductive adhesive, and the second chip 40 and the third chip 50 are respectively bonded to the second pad 12 and the third pad 13 through a non-conductive adhesive.

[0095] It can be understood that the first chip 30 can be a red (R) chip, the second chip 40 can be a green (G) chip, and the third chip 50 can be a blue (B) chip.

[0096] In the LED packaging board 100 provided by the embodiment of the present application, since the reference pads on the substrate 10 of the circuit board include a first pad 11, a second pad 12, and a third pad 13 that are connected in sequence, and the height of the surface of the first pad 11 facing away from the substrate 10 is less than the height of the surface of the second pad 12 facing away from the substrate 10, or a blocking portion 20 is provided at the connection between the first pad 11 and the second pad 12 on the surface of the reference pad facing away from the substrate 10, it can not only ensure that the distance between the first pad 11, the second pad 12, and the third pad 13 is small, so that the distance between the first chip 30, the second chip 40, and the third chip 50 is small, and the pixel pitch is small, but also avoid the conductive adhesive on the first pad 11 and the non-conductive adhesive on the second pad 12 from adsorbing and attracting each other when bonding the first chip 30, the second chip 40, and the third chip 50 on the first pad 11, the second pad 12, and the third pad 13 in the subsequent dispensing process, resulting in the displacement of the die bonding position of the LED chip, thereby improving the die bonding and packaging yield.

[0097] Optionally, the conductive adhesive can be a conductive silver adhesive, and the non-conductive adhesive can be a non-conductive white adhesive.

[0098] It can be understood that a fourth pad 14, a fifth pad 15, a sixth pad 16, and a seventh pad 17 can also be provided on the substrate 10 of the circuit board. Among them, the fourth pad 14 is connected to the third pad 13, the fifth pad 15, the sixth pad 16, and the seventh pad 17 are all arranged at intervals from the reference pad, the fifth pad 15, the sixth pad 16, and the seventh pad 17 are electrically connected to the inner layer circuit of the substrate 10 through blind vias or through vias, the fourth pad 14 and the fifth pad 15 are located on one side of the reference pad, and the sixth pad 16 and the seventh pad 17 are located on the other side of the reference pad.

[0099] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An LED encapsulation board, characterized in that, Comprising a first chip, a second chip, a third chip and a circuit board, the manufacturing method of the circuit board includes: Providing a substrate, on which a reference pad is provided, the reference pad includes a first pad, a second pad and a third pad that are sequentially connected, and the first pad, the second pad and the third pad are integrally formed; Thickening the second pad by electroplating, such that the height of the surface of the first pad facing away from the substrate is less than the height of the thickened surface of the second pad facing away from the substrate; Wherein, the first chip is bonded to the first pad by a conductive adhesive, and the second chip and the third chip are respectively bonded to the second pad and the third pad by non-conductive adhesives.

2. The LED packaging board according to claim 1, wherein, The thickening of the second pad by electroplating includes: First, film pasting: Using a vacuum laminating machine to paste a dry film, ensuring that the dry film completely adheres to the board surface of the substrate near the reference pad; Secondly, exposure: The dry film in the area where the second pad is located is not exposed, and the dry film in the area where the first pad is located is exposed and the dry film in this area is cured so that it cannot be removed by the developing solution; Then, developing: Removing the unexposed and uncured dry film, such that the second pad is not covered by the dry film; Next, electroplating and thickening: Thickening the second pad not covered by the dry film through an electroplating process, such that the height of the surface of the second pad facing away from the substrate is greater than the height of the surface of the first pad facing away from the substrate.

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