Mini LED lamp bead and packaging method thereof

Abstract

The invention discloses a Mini LED lamp bead and a packaging method thereof, and relates to the technical field of LED lamp beads, and the packaging method comprises the steps: carrying out the plasma cleaning of a copper foil plate with a preset thickness through mixed gas; forming nanoimprint glue on the copper foil plate, and performing nanoimprint on the surface of the copper foil plate according to the type of a P / N electrode bonding pad in the LED chip to form a nanoimprint pattern; etching the copper foil plate to manufacture a first bonding pad; printing solder paste on the bonding pads through the nano steel mesh, and fixing the LED chip on the first bonding pad; the LED chip and the first bonding pad are fixed through nitrogen charging reflow soldering furnace passing; coating photoresist on the back surface of the copper foil plate, and performing exposure and etching to form a circuit pattern; removing the photoresist on the back surface of the copper foil plate; according to the LED lamp bead, the solder mask layer is printed on the back face of the copper foil plate, windowing is carried out to form the second bonding pad, the copper foil plate is adopted to replace a substrate in the prior art, the characteristic that the copper foil plate is low in cost is utilized, and the cost for manufacturing the LED lamp bead can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of LED lamp beads, and particularly to a Mini LED lamp bead and its packaging method. Background Art

[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, in the process of manufacturing Mini LED lamp beads, a substrate with circuits needs to be fabricated first, and then the flip-chip LED chips are die-bonded onto the substrate. However, the existing substrates have the problem of high cost, and the prior fabrication of the substrate with circuits is inefficient. Moreover, when die-bonding the LED lamp beads onto the substrate, there is a problem of insufficient packaging density. Summary of the Invention

[0004] Based on this, the objective 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 when the existing LED lamp beads are die-bonded onto the substrate.

[0005] On the one hand, the present invention provides a packaging method for a Mini LED lamp bead, and the packaging method includes:

[0006] Obtain a copper foil board with a preset thickness;

[0007] Perform plasma cleaning on the copper foil board with a preset proportion of mixed gas to remove the oxides on the surface of the copper foil board, wherein the mixed gas includes nitrogen and hydrogen with a preset proportion;

[0008] Form a nanoimprint resist with high cations on the copper foil board, and perform nanoimprinting on the surface of the copper foil board according to the types of P / N electrode pads in the LED chip to form corresponding nanoimprint patterns;

[0009] Etch the copper foil board using etching technology to fabricate a first pad;

[0010] Print solder paste on the pad through a nano steel mesh, and fix the LED chip on the first pad using die-bonding technology;

[0011] Fix the LED chip and the first pad by passing through a nitrogen-filled reflow oven;

[0012] Coat a photoresist on the back of the copper foil board, and perform exposure and etching according to the corresponding pattern to form a circuit pattern connected to the first pad;

[0013] Remove the photoresist on the back of the copper foil board;

[0014] Print a solder mask according to the surface range on the back of the copper foil board, and open windows in the solder mask according to the circuit pattern to form second pads connected to part of the circuit pattern;

[0015] Use a cutting device to cut the copper foil board to prepare LED lamp beads of a preset size.

[0016] Further, before the step of performing plasma cleaning on the copper foil board with a mixed gas in a preset ratio, it also includes;

[0017] Use an engraving device to engrave on a copper foil board with a preset thickness to form positioning holes and preset marking points on the copper foil board.

[0018] Further, the thickness of the copper foil board is 15um - 50um.

[0019] Further, after the step of passing through a nitrogen-filled reflow oven to fixedly connect the LED chip to the pad, it also includes:

[0020] Pre-fabricate a prepreg;

[0021] Perform plasma cleaning on the copper foil board with the LED chips already die-bonded, and use vacuum hot pressing technology to hot press the prepreg on the copper foil board;

[0022] Fix the prepreg by high-temperature baking.

[0023] Further, in the step of performing plasma cleaning on the copper foil board with the LED chips already die-bonded,

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

[0025] Further, in the step of performing plasma cleaning on the copper foil board with the LED chips already die-bonded,

[0026] The gas of the plasma is argon, and the gas flow rate is 120 sccm, the radio frequency power supply power is 250 w, the vacuum degree is 30 Pa, and the cleaning time is 120 seconds.

[0027] Further, in the step of performing plasma cleaning on the copper foil board with a mixed gas in 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 supply 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, which is prepared by the above-mentioned encapsulation method of the Mini LED lamp bead. The Mini LED lamp bead includes a copper foil board having a first side and a second side, a first pad, an LED chip, a solder mask layer having a second pad, and a circuit pattern provided on the second side;

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

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

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

[0033] Wherein, 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] Further, the circuit pattern includes a red photon circuit, a green photon circuit, a blue photon circuit, and a common pole circuit;

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

[0036] The common pole circuit is used to commonly connect to the second ends of the red light chip, the green light chip, and 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 pole pad;

[0038] Wherein, the second red light pad, the second green light pad, the second blue light pad, and the common pole pad are respectively connected to parts of the red photon circuit, the green photon circuit, the blue photon circuit, and the common pole circuit.

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

[0040] In a packaging method of a Mini LED lamp bead provided by the present invention, a copper foil board with a preset thickness is used to replace the substrate in the prior art. By taking advantage of the low cost of the copper foil board, the cost of manufacturing the LED lamp bead can be greatly reduced. Then, corresponding pads are formed according to the circuit pattern, which can improve the packaging efficiency and reduce the cost. Moreover, during the preparation of the LED lamp bead, nitrogen-filled reflow soldering is used to firmly connect the LED chip to the corresponding pad. Description of the Drawings

[0041] Figure 1 It is a schematic structural diagram of a copper foil board in an embodiment of the present invention;

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

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

[0044] Figure 4 It is a schematic structural diagram of forming a circuit pattern on the copper foil board in an embodiment of the present invention;

[0045] Figure 5 It is a schematic structural diagram of printing a solder mask on the back of the copper foil board in an embodiment of the present invention;

[0046] Figure 6 It is a schematic structural diagram of opening a window in the solder mask and forming a second pad in an embodiment of the present invention;

[0047] Figure 7 It is a flow chart of the packaging method of the Mini LED lamp bead in an embodiment of the present invention.

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

[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 technical field to which this invention belongs. The terms used in the specification of this invention are for the purpose of describing specific embodiments only and are not intended to limit the invention.

[0050] In addition, the term "and / or" used herein includes any and all combinations of one or more of the related listed items. In the detailed description and claims, a list of items connected by the phrase "one of" may mean any one 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 example, 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 include a single element or multiple elements. Item B may include a single element or multiple elements. Item C may include a single element or multiple elements. In the detailed description and claims, a list of items connected by the phrase "at least one of", "at least one kind 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 "at least one of A and B" or "at least 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 "at least one of A, B, and C" or "at least one 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 C (excluding A); or all of A, B, and C. Item A may include a single element or multiple elements. Item B may include a single element or multiple elements. Item C may include a single element or multiple elements.

[0051] The present invention aims to provide a Mini LED lamp bead, including a copper foil board 1 having a first side and a second side, a first pad 2, an LED chip 3, a solder mask layer 4 having a second pad 6, and a circuit pattern 5 provided on the second side;

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

[0053] Wherein, the circuit pattern 5 is used to connect the first pad 2 and the second pad 6, and the first side and the second side are disposed opposite to each other.

[0054] Furthermore, the first pad 2 includes a first red light pad 201, a first green light pad 202, and a first blue light pad 203, and the LED chip 3 includes a red light chip 301, a green light chip 302, and a blue light 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, the circuit pattern 5 includes a red photon sub-circuit 501, a green photon sub-circuit 502, a blue photon sub-circuit 503, and a common pole sub-circuit 504;

[0057] The red photon sub-circuit 501, the green photon sub-circuit 502, and the blue photon sub-circuit 503 are respectively connected to the first end of the red light chip 301, the first end of the green light chip 302, and the first end of the blue light chip 303;

[0058] The common pole sub-circuit 504 is used to commonly connect to the second end of the red light chip 301, the second end of the green light chip 302, and the second end 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 pole pad 604;

[0060] Among them, the second red light pad 601, the second green light pad 602, the second blue light pad 603, and the common pole pad 604 are respectively connected to a part of the red photon sub-circuit 501, a part of the green photon sub-circuit 502, a part of the blue photon sub-circuit 503, and a part of the common pole sub-circuit 504.

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

[0062] Obtain a copper foil board 1 with a preset thickness;

[0063] Perform plasma cleaning on the copper foil board 1 with a preset proportion of mixed gas to remove the oxides on the surface of the copper foil board 1. Among them, the mixed gas includes nitrogen and hydrogen with a preset proportion;

[0064] Form a nano-imprinting glue with high cations on the copper foil board 1, and perform nano-imprinting on the surface of the copper foil board 1 according to the type of P / N electrode pads in the LED chip 3 to form a corresponding nano-imprinting pattern 7;

[0065] Etch the copper foil board 1 using an etching technique to fabricate the first pad 2;

[0066] Print solder paste 8 on the pad through a nano steel mesh, and fix the LED chip 3 on the first pad 2 using a die bonding process;

[0067] Fix and connect the LED chip 3 to the first pad 2 by passing through a nitrogen-filled reflow soldering furnace;

[0068] Apply photoresist on the back side of the copper foil board 1, and perform exposure and etching according to the corresponding pattern to form a circuit pattern 5 connected to the first pad 2;

[0069] Remove the photoresist on the back side of the copper foil board 1;

[0070] Print a solder mask layer 4 according to the surface range on the back side of the copper foil board 1, and open a window in the solder mask layer 4 according to the circuit pattern 5 to form a second pad 6 connected to a part of the circuit pattern 5;

[0071] Use a cutting device to cut the copper foil board 1 to prepare LED lamp beads of a preset size.

[0072] Further, before the step of performing plasma cleaning on the copper foil board 1 with a mixed gas in a preset ratio, it also includes;

[0073] Use an engraving device to engrave on the copper foil board 1 with a preset thickness to form a positioning hole 101 and a preset marking point 102 on the copper foil board 1.

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

[0075] Further, after the step of passing through a nitrogen-filled reflow oven to fixedly connect the LED chip 3 to the pad, it also includes:

[0076] Pre-fabricate a semi-cured film;

[0077] Perform plasma cleaning on the copper foil board 1 with the LED chip already fixed, and use vacuum hot pressing technology to hot press the semi-cured film onto the copper foil board 1;

[0078] Use high-temperature baking to fix the semi-cured film.

[0079] Further, in the step of performing plasma cleaning on the copper foil board 1 with the LED chip already fixed,

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

[0081] Further, in the step of performing plasma cleaning on the copper foil board 1 with the LED chip already fixed,

[0082] The gas for the plasma is argon, and the gas flow rate is 120 sccm, the radio frequency power supply power is 250 w, the vacuum degree is 30 Pa, and the cleaning time is 120 seconds.

[0083] Further, in the step of performing plasma cleaning on the copper foil board 1 with a mixed gas in a preset ratio,

[0084] The mixed gas is 95% nitrogen and 5% hydrogen. The flow rate of the mixed gas is 100 sccm, the power of the RF power supply is 280 w, the vacuum degree is 30 Pa, and the cleaning time is 180 seconds.

[0085] The first embodiment

[0086] Please refer to Figure 7 , the first embodiment of the present invention provides a packaging method for Mini LED lamp beads, including:

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

[0088] In this embodiment, the specific thickness of the copper foil board 1 can be 15 um. And the copper foil board 1 is preferably a tin-plated copper foil, an alloy-plated copper foil, a silver-plated copper foil, or a gold-plated copper foil.

[0089] S02, perform plasma cleaning on the copper foil board 1 with a mixed gas in a preset ratio to remove the oxides on the surface of the copper foil board 1. Among them, the mixed gas includes nitrogen and hydrogen in a preset ratio. It should be noted that using nitrogen-hydrogen mixed gas plasma cleaning can activate the surface of the copper foil board 1 and remove the oxides on the surface of the copper foil board 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 power of the RF power supply is 280 w, the vacuum degree is 30 Pa, and the cleaning time is 180 seconds.

[0091] In addition, for the convenience of the subsequent die bonding process on the copper foil board 1, before step S02, a carving device can also be used to carve on the copper foil board 1 with a preset thickness to form a positioning hole 101 and a preset marking point 102 on the copper foil board 1. Specifically, please refer to Figure 1 As shown, the carving device can use a laser engraving machine in the prior art, and the laser engraving machine is not a limitation on the carving device. It can also use other carving devices, which are not specifically limited here.

[0092] S03, form a nanoimprint resist with high cations on the copper foil board 1, and perform nanoimprinting on the surface of the copper foil board 1 according to the types of P / N electrode pads in the LED chip 3 to form a corresponding nanoimprint pattern 7.

[0093] Specifically, the nanoimprint resist is preferably a cationic-initiated photocuring type with a relatively high bonding strength.

[0094] S04, etch the copper foil board 1 using an etching technique to fabricate the first pad 2.

[0095] Specifically, the etching technology can adopt wet etching or reactive ion etching technology, which can precisely fabricate the first pad 2. For details, please refer to Figure 2 as shown.

[0096] S05, print solder paste 8 on the pad through a nano stencil, and fix the LED chip 3 on the first pad 2 by using die bonding technology.

[0097] S06, pass through the nitrogen-filled reflow oven to fixedly connect the LED chip 3 and the first pad 2.

[0098] The nitrogen-filled reflow soldering is used to achieve a firm connection between the LED chip 3 and the first pad 2. For details, please refer to Figure 3 as shown.

[0099] S07, coat photoresist on the back of the copper foil board 1, and perform exposure and etching 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 specifically refer to 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] Moreover, the circuit pattern 5 is specifically a red photon circuit 501, a green photon circuit 502, a blue photon circuit 503, and a common pole circuit 504;

[0102] The red photon circuit 501, the green photon circuit 502, and the blue photon circuit 503 are respectively connected to the first ends of the red light chip 301, the green light chip 302, and the blue light chip 303;

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

[0104] S08, remove the photoresist on the back of the copper foil board 1.

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

[0106] S09, print a solder mask layer 4 according to the surface range on the back of the copper foil board 1, and perform windowing on the solder mask layer 4 according to the circuit pattern 5 to form a second pad 6 connected to a part of the circuit pattern 5.

[0107] Specifically, please refer toFigure 5 As shown, for printing the solder mask layer 4 on the surface range of the back side of the copper foil board 1, please refer to Figure 6 As shown, according to the circuit pattern 5, a window is opened in the solder mask layer 4 to form a second pad 6 connected to a part of the circuit pattern 5.

[0108] S10, use a cutting device to cut the copper foil board 1 to prepare LED lamp beads of a preset size.

[0109] Specifically, the size of the cut LED lamp beads is 0.2 mm - 1.0 mm.

[0110] In some preferred embodiments, after the step of passing through a nitrogen-filled reflow oven to fixedly connect the LED chip 3 to the pad, it further includes:

[0111] Pre-prepare a semi-cured film. It should be noted that the semi-cured film can be an epoxy resin semi-cured film;

[0112] Perform plasma cleaning on the copper foil board 1 with the LED chip already mounted, and use vacuum hot pressing technology to hot press the semi-cured film onto the copper foil board 1, and use high-temperature baking to fix the semi-cured film.

[0113] Specifically, in the step of performing plasma cleaning on the copper foil board 1 with the LED chip already mounted, the gas used in the plasma cleaning is one of oxygen, argon, and nitrogen. In some preferred embodiments, the plasma gas is argon, and the gas flow rate is 120 sccm, the radio frequency power supply power is 250 w, the vacuum degree is 30 Pa, the cleaning time is 120 seconds. The semi-cured film is used to provide the colloid required for encapsulation. Vacuum hot pressing can achieve uniform distribution of the colloid, and 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, a method for encapsulating Mini LED lamp beads provided by the present invention, compared with the conventional method for encapsulating Mini LED lamp beads, has at least the following beneficial effects:

[0115] In the method for encapsulating Mini LED lamp beads provided by the present invention, a copper foil board 1 with a preset thickness is used to replace the substrate in the prior art. Utilizing the characteristic that the copper foil board 1 has a low cost, it can greatly reduce the cost of manufacturing LED lamp beads. Then, corresponding pads are formed according to the circuit pattern 5, which can improve the encapsulation efficiency and reduce the cost. And in the process of preparing LED lamp beads, passing through a nitrogen-filled reflow oven can firmly connect the LED chip 3 to the corresponding pads.

[0116] Second Embodiment

[0117] In the second embodiment provided by the present invention, a packaging method for Mini LED lamp 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 board 1 has a thickness of 18um.

[0118] Third Embodiment

[0119] In the third embodiment provided by the present invention, a packaging method for Mini LED lamp 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 board 1 has a thickness of 20um.

[0120] Fourth Embodiment

[0121] In the fourth embodiment provided by the present invention, a packaging method for Mini LED lamp 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 board 1 has a thickness of 25um.

[0122] Fifth Embodiment

[0123] In the fifth embodiment provided by the present invention, a packaging method for Mini LED lamp 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 board 1 has a thickness of 35um.

[0124] Sixth Embodiment

[0125] In the sixth embodiment provided by the present invention, a packaging method for Mini LED lamp 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 board 1 has a thickness of 50um.

[0126] In summary, the following Table 1 shows the data comparison of the first to sixth embodiments.

[0127] Embodiment Copper foil thickness (μm) Effect First Embodiment 15 Suitable for making circuits with a line pitch of 60 μm Second Embodiment 18 Suitable for making circuits with a line pitch of 80 μm Third Embodiment 20 Suitable for making circuits with a line pitch of 100 μm Fourth Embodiment 25 Suitable for making circuits with a line pitch of 100 μm Fifth Embodiment 35 Suitable for making circuits with a line pitch of 120 μm Sixth Embodiment 50 Suitable for making circuits with a line pitch of 120 μm

[0128] Table 1

[0129] Combined with the above Table 1, it can be seen that the thickness selection of the copper foil board needs to be correspondingly selected according to the P / N electrode spacing of the LED chip.

[0130] Seventh Embodiment

[0131] Please refer to Figure 3 、 Figure 4 and Figure 6As shown in the figure, a Mini LED lamp bead provided by the seventh embodiment of the present invention includes a copper foil board 1 having a first side and a second side, a first solder pad 2, an LED chip 3, a solder mask layer 4 having a second solder pad 6, and a circuit pattern 5 provided on the second side;

[0132] The LED chip 3 is provided on the first side through the first solder pad 2. The solder mask layer 4 is laminated under the second side, and the second solder pad 6 is disposed opposite to a part of the circuit pattern 5;

[0133] Among them, the circuit pattern 5 is used to connect the first solder pad 2 and the second solder pad 6.

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

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

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

[0137] The circuit pattern 5 includes four sub - circuits;

[0138] Among the four sub - circuits, three sub - circuits are respectively connected to the first ends of the red light chip 301, the green light chip 302, and the blue light chip 303, and another sub - circuit is used to commonly connect to the second ends of the red light chip 301, the green light chip 302, and the blue light chip 303.

[0139] Specifically, the circuit pattern 5 includes a red light sub - circuit 501, a green light sub - circuit 502, a blue light sub - circuit 503, and a common - pole sub - circuit 504;

[0140] The red light sub - circuit 501, the green light sub - circuit 502, and the blue light sub - circuit 503 are respectively connected to the first ends of the red light chip 301, the green light chip 302, and the blue light chip 303;

[0141] The common - pole sub - circuit 504 is used to commonly connect to the second ends of the red light chip 301, the green light chip 302, and the blue light chip 303.

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

[0143] Among them, 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 part of the red photon circuit 501, a part of the green photon circuit 502, a part of the blue photon circuit 503, and a part of the common electrode circuit 504.

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

[0145] In summary, in a Mini LED lamp bead provided by the present invention, the copper foil board is used to replace the substrate in the prior art. By taking advantage of the low cost of the copper foil board 1, the cost of manufacturing the LED lamp bead can be greatly reduced.

[0146] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0147] The above embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention should be subject to the appended claims.

Claims

1. A packaging method for Mini LED lamp beads, characterized in that, The encapsulation method includes: Obtain a copper foil board with a preset thickness; Perform plasma cleaning on the copper foil board with a mixed gas in a preset ratio to remove the oxides on the surface of the copper foil board, wherein the mixed gas includes nitrogen and hydrogen with a preset ratio; Form a nanoimprint resist with high cations on the copper foil board, and perform nanoimprinting on the surface of the copper foil board according to the types of P / N electrode pads in the LED chip to form corresponding nanoimprint patterns; Etch the copper foil board using an etching technique to fabricate a first pad; Print solder paste on the pad through a nano steel mesh, and fix the LED chip on the first pad using a die bonding process; Pass through a nitrogen-filled reflow oven to fixedly connect the LED chip to the first pad; Coat a photoresist on the back of the copper foil board, and perform exposure and etching according to the corresponding pattern to form a circuit pattern connected to the first pad; Remove the photoresist on the back of the copper foil board; Print a solder mask according to the surface range on the back of the copper foil board, and perform windowing on the solder mask according to the circuit pattern to form a second pad connected to part of the circuit pattern; Cut the copper foil board using a cutting device to prepare LED lamp beads with a preset size.

2. The encapsulation method of the Mini LED lamp bead according to claim 1, wherein Before the step of performing plasma cleaning on the copper foil board with a mixed gas in a preset ratio, it further includes; Use a engraving device to engrave on a copper foil board with a preset thickness to form positioning holes and preset marking points on the copper foil board.

3. The encapsulation method of the Mini LED lamp bead according to claim 1, characterized in that, The thickness of the copper foil board is 15um - 50um.

4. The encapsulation method of the Mini LED lamp bead according to claim 1, characterized in that, After the step of passing through a nitrogen-filled reflow oven to fixedly connect the LED chip to the pad, it further includes: Pre-fabricate a semi-cured film; Perform plasma cleaning on the copper foil board with the LED chip already die-bonded, and use a vacuum hot pressing technique to hot press the semi-cured film on the copper foil board; Fix the semi-cured film by high-temperature baking.

5. The encapsulation method of the Mini LED lamp bead according to claim 4, characterized in that, In the step of performing plasma cleaning on the copper foil board with the LED chip already die-bonded, The gas used in the plasma cleaning is one of oxygen, argon, and nitrogen.

6. The encapsulation method of the Mini LED lamp bead according to claim 5, characterized in that, In the step of performing plasma cleaning on the copper foil board with the LED chip already die-bonded, The gas of the plasma is argon, and the gas flow rate is 120 sccm, the radio frequency power supply power is 250 w, the vacuum degree is 30 Pa, and the cleaning time is 120 seconds.

7. The encapsulation method of the Mini LED lamp bead according to claim 1, characterized in that, In the step of performing plasma cleaning on the copper foil board with a mixed gas in a preset ratio, The mixed gas is 95% nitrogen and 5% hydrogen, the flow rate of the mixed gas is 100 sccm, the radio frequency power supply power is 280 w, the vacuum degree is 30 Pa, and the cleaning time is 180 seconds.

8. A Mini LED lamp bead, characterized in that, The LED lamp beads are prepared by the encapsulation method of the Mini LED lamp beads according to any one of claims 1 - 7 above. The Mini LED lamp beads include a copper foil board with a first side and a second side, a first pad, an LED chip, a solder mask with a second pad, and a circuit pattern provided on the second side; The LED chip is disposed on the first side portion through the first pad, the solder mask layer is laminated under the second side portion, and the second pad is disposed opposite to a part of the circuit pattern; Wherein, the circuit pattern is used to connect the first pad and the second pad, and the first side portion and the second side portion are disposed opposite to each other.

9. The Mini LED lamp bead according to claim 8, wherein, The first pad includes a first red light pad, a first green light pad, and a first blue light pad, and the LED chip includes a red light chip, a green light chip, and a blue light chip; Wherein, 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.

10. The Mini LED lamp bead according to claim 9, characterized in that, The circuit pattern includes a red light sub-circuit, a green light sub-circuit, a blue light sub-circuit, and a common pole sub-circuit; The red light sub-circuit, the green light sub-circuit, and the blue light sub-circuit are respectively connected to the first ends of the red light chip, the green light chip, and the blue light chip; The common pole sub-circuit is used to commonly connect to the second ends of the red light chip, the green light chip, and 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 pole pad; Wherein, the second red light pad, the second green light pad, the second blue light pad, and the common pole pad are respectively connected to parts of the red light sub-circuit, the green light sub-circuit, the blue light sub-circuit, and the common pole sub-circuit.

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