A Mini LED LED Bead and its Packaging Method

Abstract

This invention discloses a Mini LED chip and its packaging method, relating to the field of LED chip technology. The packaging method includes: plasma cleaning of a copper foil plate of a predetermined thickness using a mixed gas; forming a nano-imprint adhesive on the copper foil plate, and performing nano-imprinting on the surface of the copper foil plate according to the type of P / N electrode pads in the LED chip to form a nano-imprint pattern; etching the copper foil plate to create a first pad; printing solder paste on the pad using a nano-stencil, and fixing the LED chip onto the first pad; passing the LED chip to the first pad by nitrogen-filled reflow soldering; coating a photoresist on the back of the copper foil plate, and exposing and etching it to form a circuit pattern; removing the photoresist from the back of the copper foil plate; printing a solder resist layer on the back of the copper foil plate and creating windows to form a second pad. By using a copper foil plate to replace the substrate in the prior art, and utilizing the low cost of the copper foil plate, the cost of manufacturing LED chips can be greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of LED lamp bead technology, specifically to a Mini LED lamp bead and its packaging method. Background Technology

[0002] With the rapid development of LED technology, Mini LED has been widely used in the display field due to its advantages such as high brightness, low power consumption, and high contrast.

[0003] Traditionally, the manufacturing process of Mini LED chips requires first fabricating a substrate containing circuitry, and then bonding the flip-chip LED onto the substrate. However, existing substrates have high costs, low efficiency in fabricating the substrate containing circuitry, and insufficient packaging density when bonding the LED chips onto the substrate. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a Mini LED lamp bead and its packaging method to solve at least one of the technical problems of low efficiency, high cost and insufficient packaging density of existing LED lamp beads that are die bonded on a substrate.

[0005] This invention provides a method for packaging Mini LED chips, the packaging method comprising:

[0006] Obtain a copper foil of a preset thickness;

[0007] The copper foil is plasma cleaned using a mixed gas in a preset ratio to remove oxides from the surface of the copper foil. The mixed gas includes nitrogen and hydrogen in a preset ratio.

[0008] A highly cationic nanoimprint adhesive is formed on the copper foil, and nanoimprinting is performed on the surface of the copper foil according to the type of P / N electrode pads in the LED chip to form a corresponding nanoimprint pattern.

[0009] The copper foil is etched using an etching technique to create the first pad.

[0010] Solder paste is printed on the pads using a nano-steel mesh, and the LED chip is fixed onto the first pad using a die bonding process.

[0011] The LED chip is fixedly connected to the first pad by passing it through a nitrogen-filled reflow oven.

[0012] Photoresist is applied to the back of the copper foil, and exposure and etching are performed according to the corresponding pattern to form a circuit pattern connected to the first pad.

[0013] Remove the photoresist from the back of the copper foil plate;

[0014] A solder resist layer is printed on the surface area of ​​the back of the copper foil board, and a window is made in the solder resist layer according to the circuit pattern to form a second pad connected to a portion of the circuit pattern;

[0015] The copper foil plate is cut using a cutting device to prepare LED beads of a preset size.

[0016] Furthermore, prior to the step of plasma cleaning the copper foil using a mixed gas in a preset ratio, the method further includes:

[0017] Engraving equipment is used to engrave on a copper foil plate of a predetermined thickness to form positioning holes and predetermined marking points on the copper foil plate.

[0018] Furthermore, the thickness of the copper foil plate is 15um-50um.

[0019] Furthermore, after the step of fixing the LED chip to the pad by passing it through a nitrogen-filled reflow oven, the method further includes:

[0020] Pre-cured film;

[0021] The copper foil plate that has been crystal-bonded is subjected to plasma cleaning, and the semi-cured film is hot-pressed onto the copper foil plate using vacuum hot pressing technology.

[0022] The semi-cured film is fixed by high-temperature baking.

[0023] Furthermore, in the step of plasma cleaning the already solidified copper foil,

[0024] The gas used in the plasma cleaning is one of oxygen, argon, or nitrogen.

[0025] Furthermore, in the step of plasma cleaning the already solidified copper foil,

[0026] The plasma is generated using argon gas with a flow rate of 120 sccm, a radio frequency power of 250 W, a vacuum of 30 Pa, and a cleaning time of 120 seconds.

[0027] Furthermore, in the step of performing plasma cleaning on the copper foil using a mixed gas of a preset ratio,

[0028] The mixed gas is 95% nitrogen and 5% hydrogen, the flow rate of the mixed gas is 100 sccm, the radio frequency power is 280 W, the vacuum degree is 30 Pa, and the cleaning time is 180 seconds.

[0029] Another aspect of the present invention is to provide a Mini LED lamp bead, wherein the LED lamp bead is prepared by the Mini LED lamp bead packaging method described above, and the Mini LED lamp bead includes a copper foil plate having a first side and a second side, a first pad, an LED chip, a solder resist layer having a second pad, and a circuit pattern disposed on the second side.

[0030] The LED chip is disposed on the first side via the first pad, and the solder mask layer is stacked under the second side. The second pad is disposed opposite to a portion of the circuit pattern.

[0031] The circuit pattern is used to connect the first pad and the second pad, and the first side and the second side are arranged opposite to each other.

[0032] Furthermore, the first pad includes a first red pad, a first green pad, and a first blue pad, and the LED chip includes a red chip, a green chip, and a blue chip;

[0033] The red light chip is connected to the first red light pad, the green light chip is connected to the first green light pad, and the blue light chip is connected to the first blue light pad.

[0034] Furthermore, the circuit pattern includes a red photonic circuit, a green photonic circuit, a blue photonic circuit, and a common pole circuit;

[0035] The red photonic circuit, the green photonic circuit, and the blue photonic circuit are respectively connected to the first end of the red light chip, the first end of the green light chip, and the first end of the blue light chip;

[0036] The common pole circuit is used to connect together with the second terminal of the red light chip, the second terminal of the green light chip and the second terminal of the blue light chip;

[0037] The second pad includes a second red light pad, a second green light pad, a second blue light pad, and a common electrode pad;

[0038] The second red light pad, the second green light pad, the second blue light pad, and the common electrode pad are respectively connected to a portion of the red photonic circuit, a portion of the green photonic circuit, a portion of the blue photonic circuit, and a portion of the common electrode circuit.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] In the packaging method of Mini LED beads provided by the present invention, a copper foil plate of preset thickness is used to replace the substrate in the prior art. The copper foil plate has the characteristics of low cost, which can greatly reduce the cost of manufacturing LED beads. Then, according to the circuit pattern, the corresponding pads are formed, which can improve the packaging efficiency and reduce the cost. Furthermore, in the process of manufacturing LED beads, nitrogen-filled reflow soldering is used to achieve a firm connection between the LED chip and the corresponding pads. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the structure of a copper foil plate in one embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the structure of forming a nanoimprint pattern and a first pad on a copper foil board in one embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram of the structure of fixing an LED chip on a first pad in one embodiment of the present invention;

[0044] Figure 4 This is a schematic diagram of a circuit pattern formed on a copper foil substrate according to an embodiment of the present invention;

[0045] Figure 5 This is a schematic diagram of the structure of printing a solder resist layer on the back of a copper foil plate in one embodiment of the present invention;

[0046] Figure 6 This is a schematic diagram of a structure in which a window is made in the solder mask layer to form a second pad in one embodiment of the present invention;

[0047] Figure 7 This is a flowchart of a Mini LED lamp bead packaging method according to an embodiment of the present invention.

[0048] In the diagram: 1. Copper foil board; 101. Positioning hole; 102. Preset mark point; 2. First pad; 201. First red pad; 202. First green pad; 203. First blue pad; 3. LED chip; 301. Red chip; 302. Green chip; 303. Blue chip; 4. Solder resist layer; 5. Circuit pattern; 501. Red photonic circuit; 502. Green photonic circuit; 503. Blue photonic circuit; 504. Common electrode circuit; 6. Second pad; 601. Second red pad; 602. Second green pad; 603. Second blue pad; 604. Common electrode pad; 7. Nanoimprint pattern; 8. Solder paste. Detailed Implementation

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0050] Furthermore, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. In the detailed description and claims, a list of items connected by the term "one of" may mean any of the listed items. For example, if items A and B are listed, then the phrase "one of A and B" means only A or only B. In another instance, if items A, B, and C are listed, then the phrase "one of A, B, and C" means only A; only B; or only C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements. In the detailed description and claims, a list of items connected by the terms "less than one of," "less than one of," or other similar terms may mean any combination of the listed items. For example, if items A and B are listed, then the phrase "less than one of A and B" or "less than one of A or B" means only A; only B; or A and B. In another example, if items A, B, and C are listed, then the phrase "one less of A, B, and C" or "one less of A, B, or C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and specification 4C (excluding A); or all of A, B, and C. Item A may contain a single element or multiple elements. Item B may contain a single element or multiple elements. Item C may contain a single element or multiple elements.

[0051] The present invention provides a Mini LED lamp bead, comprising a copper foil plate 1 having a first side and a second side, a first pad 2, an LED chip 3, a solder resist layer 4 having a second pad 6, and a circuit pattern 5 disposed on the second side;

[0052] LED chip 3 is disposed on the first side via first pad 2, solder mask layer 4 is stacked under the second side, and second pad 6 is disposed opposite to part of circuit pattern 5;

[0053] The circuit pattern 5 is used to connect the first pad 2 and the second pad 6, with the first side and the second side arranged opposite to each other.

[0054] Furthermore, the first pad 2 includes a first red pad 201, a first green pad 202, and a first blue pad 203, and the LED chip 3 includes a red chip 301, a green chip 302, and a blue chip 303.

[0055] Among them, the red light chip 301 is connected to the first red light pad 201, the green light chip 302 is connected to the first green light pad 202, and the blue light chip 303 is connected to the first blue light pad 203.

[0056] Furthermore, circuit pattern 5 includes red photonic circuit 501, green photonic circuit 502, blue photonic circuit 503, and common pole circuit 504;

[0057] Red photonic circuit 501, green photonic circuit 502 and blue photonic circuit 503 are respectively connected to the first end of red light chip 301, the first end of green light chip 302 and the first end of blue light chip 303.

[0058] The common pole circuit 504 is used to connect together with the second terminal of the red light chip 301, the second terminal of the green light chip 302 and the second terminal of the blue light chip 303;

[0059] The second pad 6 includes a second red light pad 601, a second green light pad 602, a second blue light pad 603, and a common electrode pad 604;

[0060] The second red light pad 601, the second green light pad 602, the second blue light pad 603, and the common electrode pad 604 are respectively connected to a portion of the red photonic circuit 501, a portion of the green photonic circuit 502, a portion of the blue photonic circuit 503, and a portion of the common electrode circuit 504.

[0061] In addition, a packaging method for Mini LED chips is also provided, including:

[0062] Obtain copper foil plate 1 of preset thickness;

[0063] A plasma cleaning process is performed on the copper foil plate 1 using a mixed gas in a preset ratio to remove oxides from the surface of the copper foil plate 1. The mixed gas includes nitrogen and hydrogen in a preset ratio.

[0064] A highly cationic nanoimprint adhesive is formed on the copper foil 1, and nanoimprinting is performed on the surface of the copper foil 1 according to the type of P / N electrode pads in the LED chip 3 to form a corresponding nanoimprint pattern 7.

[0065] The copper foil plate 1 is etched using etching technology to create the first pad 2;

[0066] Solder paste 8 is printed on the pads using a nano steel mesh, and the LED chip 3 is fixed onto the first pad 2 using a die bonding process.

[0067] The LED chip 3 is fixedly connected to the first pad 2 by passing it through a nitrogen-filled reflow oven.

[0068] Photoresist is applied to the back of the copper foil 1, and exposure and etching are performed according to the corresponding pattern to form a circuit pattern 5 connected to the first pad 2.

[0069] Remove the photoresist from the back of copper foil 1;

[0070] A solder resist layer 4 is printed on the surface area of ​​the back of the copper foil 1, and a window is made in the solder resist layer 4 according to the circuit pattern 5 to form a second pad 6 connected to a portion of the circuit pattern 5.

[0071] The copper foil plate 1 is cut using a cutting device to prepare LED beads of a preset size.

[0072] Furthermore, prior to the step of plasma cleaning the copper foil plate 1 using a mixed gas of a preset ratio, the method further includes:

[0073] Engraving equipment is used to engrave on a copper foil plate 1 of a preset thickness to form positioning holes 101 and preset marking points 102 on the copper foil plate 1.

[0074] In some preferred embodiments, the thickness of the copper foil 1 is 15um-50um.

[0075] Furthermore, after the step of fixing the LED chip 3 to the pads by passing it through a nitrogen-filled reflow oven, the process also includes:

[0076] Pre-cured film;

[0077] The solidified copper foil plate 1 is plasma cleaned, and the semi-cured film is hot-pressed onto the copper foil plate 1 using vacuum hot pressing technology.

[0078] The semi-cured film is fixed by high-temperature baking.

[0079] Furthermore, in the step of plasma cleaning the already solidified copper foil plate 1,

[0080] The gas used in plasma cleaning is one of oxygen, argon, or nitrogen.

[0081] Furthermore, in the step of plasma cleaning the already solidified copper foil plate 1,

[0082] The plasma gas used is argon, with a flow rate of 120 sccm, an RF power of 250 W, a vacuum of 30 Pa, and a cleaning time of 120 seconds.

[0083] Furthermore, in the step of plasma cleaning the copper foil 1 using a pre-proportioned mixed gas,

[0084] The mixed gas consisted of 95% nitrogen and 5% hydrogen, with a flow rate of 100 sccm, a radio frequency power of 280 W, a vacuum of 30 Pa, and a cleaning time of 180 seconds.

[0085] First Embodiment

[0086] Please see Figure 7 The first embodiment of the present invention shows a method for packaging Mini LED chips, including:

[0087] S01, Obtain copper foil plate 1 of a preset thickness. It should be noted that the thickness of copper foil plate 1 is 15um-50um.

[0088] In this embodiment, the specific thickness of the copper foil plate 1 can be 15 μm, and the copper foil plate 1 is preferably tin-plated copper foil, alloy-plated copper foil, silver-plated copper foil, or gold-plated copper foil.

[0089] S02, a mixed gas with a preset ratio is used to perform plasma cleaning on the copper foil plate 1 to remove oxides on the surface of the copper foil plate 1. The mixed gas includes nitrogen and hydrogen in a preset ratio. It should be noted that plasma cleaning with nitrogen-hydrogen mixed gas can activate the surface of the copper foil plate 1 and remove oxides from the surface of the copper foil plate 1.

[0090] In some preferred embodiments, the mixed gas is 95% nitrogen and 5% hydrogen, the flow rate of the mixed gas is 100 sccm, the radio frequency power is 280 W, the vacuum degree is 30 Pa, and the cleaning time is 180 seconds.

[0091] In addition, to facilitate the subsequent die bonding process on the copper foil plate 1, before step S02, an engraving device can be used to engrave on the copper foil plate 1 of a preset thickness to form positioning holes 101 and preset marking points 102 on the copper foil plate 1. For details, please refer to [link to relevant documentation]. Figure 1 As shown, the engraving equipment can be a laser engraving machine from the existing technology, and the laser engraving machine is not a limitation on the engraving equipment; other engraving equipment can also be used, and no special limitation is made here.

[0092] S03, a highly cationic nanoimprint adhesive is formed on the copper foil 1, and nanoimprinting is performed on the surface of the copper foil 1 according to the type of P / N electrode pads in the LED chip 3 to form a corresponding nanoimprint pattern 7.

[0093] Specifically, the nanoimprint adhesive is preferably a cationic photocurable type with high bonding strength.

[0094] S04, etching technology is used to etch the copper foil plate 1 to create the first pad 2.

[0095] Specifically, the etching technology can employ wet etching or reactive ion etching, which can precisely fabricate the first pad 2. See details... Figure 2 As shown.

[0096] S05, solder paste 8 is printed on the pads using a nano-steel mesh, and the LED chip 3 is fixed onto the first pad 2 using a die bonding process.

[0097] S06, the LED chip 3 is fixedly connected to the first pad 2 by passing through a nitrogen-filled reflow oven.

[0098] Nitrogen-filled reflow soldering is used to achieve a firm connection between the LED chip 3 and the first pad 2. See details... Figure 3 As shown.

[0099] S07, photoresist is applied to the back of the copper foil 1, and exposure and etching are performed according to the corresponding pattern to form a circuit pattern 5 connected to the first pad 2.

[0100] For a further understanding of this case, please refer to the following: Figure 4 As shown, in this example, the LED chip 3 includes a red light chip 301, a green light chip 302, and a blue light chip 303. Correspondingly, the first pad 2 includes a first red light pad 201, a first green light pad 202, and a first blue light pad 203. The red light chip 301 is connected to the first red light pad 201, the green light chip 302 is connected to the first green light pad 202, and the blue light chip 303 is connected to the first blue light pad 203.

[0101] Furthermore, circuit diagram 5 specifically includes red photonic circuit 501, green photonic circuit 502, blue photonic circuit 503, and common pole circuit 504;

[0102] Red photonic circuit 501, green photonic circuit 502 and blue photonic circuit 503 are respectively connected to the first end of red light chip 301, the first end of green light chip 302 and the first end of blue light chip 303.

[0103] The common pole circuit 504 is used to connect together with the second terminal of the red light chip 301, the second terminal of the green light chip 302 and the second terminal of the blue light chip 303.

[0104] S08, Remove the photoresist from the back of copper foil 1.

[0105] It should be noted that the photoresist outside of circuit pattern 5 has been removed.

[0106] S09, a solder resist layer 4 is printed according to the surface area of ​​the back side of the copper foil board 1, and a window is made in the solder resist layer 4 according to the circuit pattern 5 to form a second pad 6 connected to a portion of the circuit pattern 5.

[0107] Specifically, please refer to Figure 5 As shown, the solder resist layer 4 is printed on the surface area of ​​the back side of the copper foil board 1. Please refer to [link to documentation]. Figure 6 As shown, a window is made in the solder mask layer 4 according to the circuit pattern 5 to form a second pad 6 that is connected to a portion of the circuit pattern 5.

[0108] S10, the copper foil plate 1 is cut using a cutting device to prepare LED beads of a preset size.

[0109] Specifically, the cut LED beads are 0.2mm-1.0mm in size.

[0110] In some preferred embodiments, after the step of fixing the LED chip 3 to the pads by nitrogen-filled reflow soldering, the method further includes:

[0111] Pre-cured film; it should be noted that the pre-cured film can be made of epoxy resin.

[0112] The copper foil plate 1 with solidified crystal is plasma cleaned, and the semi-cured film is hot-pressed onto the copper foil plate 1 using vacuum hot pressing technology. The semi-cured film is then fixed by high-temperature baking.

[0113] Specifically, in the step of plasma cleaning the die-bonded copper foil 1, the gas used in the plasma cleaning is one of oxygen, argon, or nitrogen. In some preferred embodiments, argon is used as the plasma gas, and the gas flow rate is 120 sccm, the RF power supply power is 250 W, the vacuum degree is 30 Pa, and the cleaning time is 120 seconds. A semi-cured film is used to provide the colloid required for encapsulation. Vacuum hot pressing can achieve uniform distribution of the colloid. Finally, high-temperature baking is used to cure the colloid to improve the encapsulation stability and solve the problem of insufficient encapsulation density.

[0114] In summary, the Mini LED chip packaging method provided by this invention has at least the following advantages compared to traditional Mini LED chip packaging methods:

[0115] In the packaging method of Mini LED beads provided by the present invention, a copper foil plate 1 of a preset thickness is used to replace the substrate in the prior art. The copper foil plate 1 has the characteristics of low cost, which can greatly reduce the cost of manufacturing LED beads. Then, according to the circuit pattern 5, the corresponding pads are formed, which can improve the packaging efficiency and reduce the cost. In addition, in the process of manufacturing LED beads, nitrogen-filled reflow soldering is used to firmly connect the LED chip 3 to the corresponding pads.

[0116] Second Embodiment

[0117] In the second embodiment of the present invention, a packaging method for Mini LED beads is provided. The packaging method in this embodiment is basically the same as that in the first embodiment. In this embodiment, the copper foil plate 1 has a thickness of 18um.

[0118] Third Embodiment

[0119] The third embodiment of the present invention provides a packaging method for Mini LED beads. The packaging method in this embodiment is basically the same as that in the first embodiment. In this embodiment, the copper foil plate 1 has a thickness of 20um.

[0120] Fourth embodiment

[0121] The fourth embodiment of the present invention provides a packaging method for Mini LED beads. The packaging method in this embodiment is basically the same as the packaging method in the first embodiment. In this embodiment, the copper foil plate 1 has a thickness of 25um.

[0122] Fifth embodiment

[0123] The fifth embodiment of the present invention provides a packaging method for Mini LED beads. The packaging method in this embodiment is basically the same as the packaging method in the first embodiment. In this embodiment, the copper foil plate 1 has a thickness of 35um.

[0124] Sixth Embodiment

[0125] The sixth embodiment of the present invention provides a packaging method for Mini LED beads. The packaging method in this embodiment is basically the same as the packaging method in the first embodiment. In this embodiment, the copper foil plate 1 has a thickness of 50um.

[0126] In summary, Table 1 below provides a data comparison of the first to sixth embodiments.

[0127]

[0128] Table 1

[0129] As shown in Table 1 above, the thickness of the copper foil plate should be selected according to the P / N electrode spacing of the LED chip.

[0130] Seventh Embodiment

[0131] Please see Figure 3 , Figure 4 and Figure 6As shown, a Mini LED lamp bead provided in the seventh embodiment of the present invention includes a copper foil plate 1 having a first side and a second side, a first pad 2, an LED chip 3, a solder resist layer 4 having a second pad 6, and a circuit pattern 5 disposed on the second side.

[0132] LED chip 3 is disposed on the first side via first pad 2, solder mask layer 4 is stacked under the second side, and second pad 6 is disposed opposite to part of circuit pattern 5;

[0133] The circuit pattern 5 is used to connect the first pad 2 and the second pad 6.

[0134] Specifically, the first side and the second side are arranged opposite to each other, the first side is the front side of the copper foil plate, and the second side is the back side of the copper foil plate.

[0135] It should be noted that the first pad 2 includes a first red pad 201, a first green pad 202, and a first blue pad 203, and the LED chip 3 includes a red chip 301, a green chip 302, and a blue chip 303.

[0136] Among them, the red light chip 301 is connected to the first red light pad 201, the green light chip 302 is connected to the first green light pad 202, and the blue light chip 303 is connected to the first blue light pad 203.

[0137] Circuit diagram 5 includes four sub-circuits;

[0138] Three of the four sub-circuits are connected to the first terminal of the red light chip 301, the first terminal of the green light chip 302, and the first terminal of the blue light chip 303, respectively. The other sub-circuit is used to connect together with the second terminal of the red light chip 301, the second terminal of the green light chip 302, and the second terminal of the blue light chip 303.

[0139] Specifically, circuit diagram 5 includes red photonic circuit 501, green photonic circuit 502, blue photonic circuit 503, and common pole circuit 504;

[0140] Red photonic circuit 501, green photonic circuit 502 and blue photonic circuit 503 are respectively connected to the first end of red light chip 301, the first end of green light chip 302 and the first end of blue light chip 303.

[0141] The common pole circuit 504 is used to connect together with the second terminal of the red light chip 301, the second terminal of the green light chip 302 and the second terminal of the blue light chip 303.

[0142] The second pad 6 includes a second red light pad 601, a second green light pad 602, a second blue light pad 603, and a common electrode pad 604;

[0143] The second red light pad 601, the second green light pad 602, the second blue light pad 603, and the common electrode pad 604 are respectively connected to a portion of the red photonic circuit 501, a portion of the green photonic circuit 502, a portion of the blue photonic circuit 503, and a portion of the common electrode circuit 504.

[0144] In some preferred embodiments, the thickness of the copper foil 1 is 15um-50um.

[0145] In summary, in the Mini LED lamp bead provided by the present invention, a copper foil plate is used to replace the substrate in the prior art. The low cost of the copper foil plate 1 can greatly reduce the cost of manufacturing LED lamp beads.

[0146] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0147] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for packaging Mini LED chips, characterized in that, The encapsulation method includes: Obtain a copper foil of a preset thickness; The copper foil is plasma cleaned using a mixed gas in a preset ratio to remove oxides from the surface of the copper foil. The mixed gas includes nitrogen and hydrogen in a preset ratio. A highly cationic nanoimprint adhesive is formed on the copper foil, and nanoimprinting is performed on the surface of the copper foil according to the type of P / N electrode pads in the LED chip to form a corresponding nanoimprint pattern. The copper foil is etched using an etching technique to create the first pad. Solder paste is printed on the pads using a nano-steel mesh, and the LED chip is fixed onto the first pad using a die bonding process. The LED chip is fixedly connected to the first pad by passing it through a nitrogen-filled reflow oven. Photoresist is applied to the back of the copper foil, and exposure and etching are performed according to the corresponding pattern to form a circuit pattern connected to the first pad. Remove the photoresist from the back of the copper foil plate; A solder resist layer is printed on the surface area of ​​the back of the copper foil board, and a window is made in the solder resist layer according to the circuit pattern to form a second pad connected to a portion of the circuit pattern; The copper foil plate is cut using a cutting device to prepare LED beads of a preset size; Before the step of performing plasma cleaning of the copper foil using a mixed gas in a preset ratio, the method further includes: Engraving equipment is used to engrave on a copper foil plate of a predetermined thickness to form positioning holes and predetermined marking points on the copper foil plate; The thickness of the copper foil plate is 15um-50um; After the step of fixing the LED chip to the pad by passing it through a nitrogen-filled reflow oven, the method further includes: Pre-cured film; The copper foil plate that has been crystal-bonded is subjected to plasma cleaning, and the semi-cured film is hot-pressed onto the copper foil plate using vacuum hot pressing technology. The semi-cured film is fixed by high-temperature baking.

2. The packaging method for Mini LED beads according to claim 1, characterized in that, In the step of plasma cleaning the already solidified copper foil, The gas used in the plasma cleaning is one of oxygen, argon, or nitrogen.

3. The packaging method for Mini LED beads according to claim 2, characterized in that, In the step of plasma cleaning the already solidified copper foil, The plasma is generated using argon gas with a flow rate of 120 sccm, a radio frequency power of 250 W, a vacuum of 30 Pa, and a cleaning time of 120 seconds.

4. The packaging method for Mini LED beads according to claim 1, characterized in that, In the step of using a mixed gas of a preset ratio to perform plasma cleaning on the copper foil, The mixed gas consists of 95% nitrogen and 5% hydrogen, with a flow rate of 100 sccm, a radio frequency power of 280 W, a vacuum of 30 Pa, and a cleaning time of 180 seconds.

5. A Mini LED lamp bead, characterized in that, The LED bead is prepared by the packaging method of the Mini LED bead according to any one of claims 1-4. The Mini LED bead includes a copper foil plate having a first side and a second side, a first pad, an LED chip, a solder resist layer having a second pad, and a circuit pattern disposed on the second side. The LED chip is disposed on the first side via the first pad, and the solder mask layer is stacked under the second side. The second pad is disposed opposite to a portion of the circuit pattern. The circuit pattern is used to connect the first pad and the second pad, and the first side and the second side are arranged opposite to each other.

6. The Mini LED lamp bead according to claim 5, characterized in that, The first pad includes a first red pad, a first green pad, and a first blue pad; the LED chip includes a red chip, a green chip, and a blue chip. The red light chip is connected to the first red light pad, the green light chip is connected to the first green light pad, and the blue light chip is connected to the first blue light pad.

7. The Mini LED lamp bead according to claim 6, characterized in that, The circuit diagram includes a red photonic circuit, a green photonic circuit, a blue photonic circuit, and a common pole circuit; The red photonic circuit, the green photonic circuit, and the blue photonic circuit are respectively connected to the first end of the red light chip, the first end of the green light chip, and the first end of the blue light chip; The common pole circuit is used to connect together with the second terminal of the red light chip, the second terminal of the green light chip and the second terminal of the blue light chip; The second pad includes a second red light pad, a second green light pad, a second blue light pad, and a common electrode pad; The second red light pad, the second green light pad, the second blue light pad, and the common electrode pad are respectively connected to a portion of the red photonic circuit, a portion of the green photonic circuit, a portion of the blue photonic circuit, and a portion of the common electrode circuit.

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