LED wafer packaging method and LED lamp bead and module

Abstract

This application relates to an LED chip packaging method and LED beads / modules, belonging to the field of Mini LED. The LED chip packaging method includes: mounting a plurality of LED chips onto a circuit board; molding and curing a fluorescent colloid on one side of the circuit board where the LED chips are located, with the fluorescent colloid covering the LED chips; processing an encapsulation groove surrounding the LED chips on the fluorescent colloid; and molding or injection molding a black protective frame in the encapsulation groove and curing it. Beneficial technical effects: The LED chip packaging method of this application involves molding a fluorescent colloid onto the LED chip in one step, then processing an encapsulation groove surrounding the LED chip on the fluorescent colloid, and finally injection molding or molding a black protective adhesive into the encapsulation groove. The black protective adhesive and the fluorescent colloid are tightly bonded together and fill the light leakage channel between the LED chip and the PCB board, eliminating gaps and thus solving the problem of light leakage in Mini LED beads. Furthermore, the black protective adhesive obtained by injection molding or molding is thin, further reducing the size of the LED beads.

Description

Technical Field

[0001] This application relates to the field of Mini LED, and in particular to an LED chip packaging method and LED beads and modules. Background Technology

[0002] In existing technologies, Mini LED chip packaging uses black protective glue to absorb and block stray light, isolate the LED chip, and solve the problem of light mixing / crossing.

[0003] However, the black adhesive does not have good fluidity and it is difficult to completely penetrate the extremely narrow gap between the LED chip and the PCB board (the LED chip is soldered onto the circuit board, and there is a solder joint height of tens of micrometers between its bottom and the circuit board). Therefore, there is a light leakage channel between the LED chip and the PCB board. After the light is emitted from this channel, it is reflected on the surface of the PCB board and then enters the adjacent LED chip area, which still results in light leakage and crosstalk problems.

[0004] Moreover, after the black glue is poured in, it shrinks as it cures, causing a gap to appear between the fluorescent colloid and the black glue light-shielding frame. Light emitted from the side of the LED chip enters this air gap and undergoes total internal reflection at the interface, causing light crosstalk.

[0005] In addition, the thicker light-shielding frame obtained by the potting black glue process severely restricts the miniaturization of Mini LED beads. Summary of the Invention

[0006] To completely solve the problems of light leakage and the inability to further reduce the size of Mini LED beads, this application provides an LED chip packaging method, as well as LED beads and modules.

[0007] In one aspect of this disclosure, an LED chip packaging method is provided, comprising: Several LED chips are mounted onto a circuit board; A fluorescent colloid is molded and cured on one side of the circuit board where the LED chip is located, and the fluorescent colloid covers the LED chip. Encapsulation grooves that wrap around LED chips are fabricated on fluorescent colloids; The black adhesive light-shielding frame is molded or injection molded into the encapsulation groove and then cured. Cut the black vinyl light-blocking frame and circuit board along the center line of the black vinyl light-blocking frame.

[0008] By adopting the above technical solution, the black protective adhesive and fluorescent adhesive are tightly bonded together and filled into the light leakage channel between the LED chip and the PCB board, eliminating gaps and thus solving the problem of light leakage in Mini LED beads. In addition, the black protective adhesive obtained by injection molding or compression molding is thin, further reducing the size of the LED beads.

[0009] Preferably, the encapsulation groove extends to the circuit board.

[0010] By adopting the above technical solution, the light leakage channel below the encapsulation groove is eliminated, ensuring a reliable, effective, and thorough solution to the problem of light leakage in Mini LED beads.

[0011] Preferably, a number of LED chips are arranged in a rectangular array on the circuit board, and the encapsulation slots are rectangular, with the encapsulation slots of two adjacent LED chips overlapping.

[0012] By adopting the above technical solution, it is convenient to quickly process the encapsulation slot for each LED chip.

[0013] Preferably, the step of molding and curing the black adhesive light-shielding frame in the encapsulation groove includes: The cooled black rubber cake is preheated to 75-85℃ to obtain black rubber fluid. The black adhesive fluid is injected into a vacuum molding device to fill the encapsulation tank and the gap between the LED chip and the circuit board. Maintain a curing temperature of 150-175°C inside the molding equipment for 2-4 minutes until the black glue fluid solidifies, forming a black glue light-blocking frame. After demolding, place the black glue light-blocking frame into the baking equipment for secondary curing. The curing temperature is 120-150℃ and the time is 3-4 hours. Remove the burrs from the black vinyl blackout frame.

[0014] By adopting the above technical solution, the fluorescent colloid and the black glue light-shielding frame are firmly bonded and sealed together, eliminating the possibility of gaps between the fluorescent colloid and the black glue light-shielding frame, as well as between the LED chip and the PCB board, ensuring reliable LED chip packaging quality and completely eliminating the problem of light leakage in Mini LED beads.

[0015] Preferably, the step of injection molding and curing the black adhesive light-shielding frame in the encapsulation groove includes: The thermoplastic black rubber material is dried and then injected into the injection molding equipment; The injection molding equipment heats the black rubber material to a melt and then injects it into the encapsulation tank; After being held under pressure for a period of time, a curing process is performed to obtain a black glue light-blocking frame.

[0016] By adopting the above technical solutions, LED chip packaging quality comparable to that of compression molding can be obtained using injection molding. Compared with compression molding, injection molding has lower cost and higher production efficiency, making it very suitable for mass production.

[0017] Preferably, the injection molding equipment injects the black rubber material into the encapsulation tank at an injection pressure of 80-150 MPa and an injection time of 0.5-2 seconds; The holding time is 5 to 15 seconds, and the holding pressure is 80 to 100% of the injection pressure. The curing process involves cooling the black adhesive material in the encapsulation tank for 20 to 60 seconds.

[0018] By adopting the above technical solutions, it is ensured that the injection molding process can also achieve LED chip packaging quality comparable to that of the compression molding process.

[0019] Preferably, the processing method for creating the encapsulation groove surrounding the LED chip on the fluorescent colloid is any one of laser processing, etching processing, or machining.

[0020] In another aspect of this disclosure, an LED light bead is provided, comprising: The circuit board has LED chips on one side. A fluorescent colloid is tightly bonded to the side of a circuit board where LED chips are located, with the LED chips located inside the fluorescent colloid. A black vinyl light-shielding frame is embedded in a fluorescent colloid and surrounds the LED chip, with the black vinyl light-shielding frame and the fluorescent colloid being tightly connected.

[0021] By adopting the above technical solution, the black protective adhesive and fluorescent adhesive in the LED lamp bead are tightly bonded together and filled into the light leakage channel between the LED chip and the PCB board, eliminating gaps and thus solving the problem of light leakage in Mini LED lamp beads. In addition, the black protective adhesive obtained by injection molding or compression molding is thin, further reducing the size of the lamp bead.

[0022] Preferably, the upper surface of the black adhesive light-shielding frame is flush with the outer surface of the fluorescent adhesive, and the lower surface of the black adhesive light-shielding frame is in close contact with the circuit board.

[0023] By adopting the above technical solution, the black vinyl light-shielding frame penetrates into the light leakage channel between the LED chip and the PCB board, eliminating gaps and light leakage dead angles.

[0024] In another aspect of this disclosure, an LED module is provided, including LED beads.

[0025] Beneficial technical effects: The LED chip packaging method of this application involves covering the LED chip with phosphor colloid in one molding process, then processing the packaging groove around the LED chip on the phosphor colloid, and finally injecting or molding black protective glue into the packaging groove. The black protective glue and phosphor colloid are tightly bonded together and fill the light leakage channel between the LED chip and the PCB board, eliminating gaps and thus solving the problem of light leakage of Mini LED beads. Moreover, the black protective glue obtained by injection molding or molding is thin, further reducing the size of the LED beads. Attached Figure Description

[0026] Figure 1 This is a flowchart of the LED chip packaging method in the embodiments of this application.

[0027] Figure 2 This is a flowchart of the process of molding a black adhesive light-shielding frame into a packaging groove and curing it in an embodiment of this application.

[0028] Figure 3 This is a flowchart illustrating the process of injection molding a black adhesive light-shielding frame into a packaging groove and then curing it, as described in this application embodiment.

[0029] Figure 4 This is a schematic diagram of the structure of the LED lamp beads in the embodiments of this application.

[0030] Figure 5 This is an internal structural diagram of the LED beads in the embodiments of this application.

[0031] Explanation of reference numerals in the attached diagram: 1. Fluorescent colloid; 2. Black vinyl light-shielding frame; 3. PCB board; 4. LED chip. Detailed Implementation

[0032] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0033] The following is in conjunction with the appendix Figures 1-5 This application will be described in further detail.

[0034] In one aspect of this disclosure, an LED chip packaging method is provided, such as... Figure 1 As shown, the LED chip packaging method includes: S1. Install several LED chips 4 onto the circuit board 3; S2. A fluorescent colloid 1 is molded and cured on one side of the circuit board 3 where the LED chip 4 is located, and the fluorescent colloid 1 covers the LED chip 4. S3. A packaging groove for wrapping the LED chip 4 is processed on the fluorescent colloid 1; S4. Mold or injection mold the black glue light-shielding frame 2 in the encapsulation groove and cure it; S5. Cut the black glue light-blocking frame 2 and the circuit board 3 along the center line of the black glue light-blocking frame 2.

[0035] By adopting the above technical solution, the black protective adhesive and fluorescent colloid 1 are tightly bonded together and filled into the light leakage channel between the LED chip 4 and the PCB board 3, eliminating gaps and thus solving the problem of light leakage in Mini LED beads. In addition, the black protective adhesive obtained by injection molding or compression molding is thin, further reducing the size of the LED beads.

[0036] In step S1, several LED chips 4 are mounted onto circuit board 3. The appropriate number of LED chips 4 is selected according to the production design requirements. The LED chips 4 are soldered onto circuit board 3, with a solder joint height of several tens of micrometers between their bottom and the circuit board 3. During subsequent molding or injection molding, black protective adhesive fills the gap between the LED chips 4 and circuit board 3, thereby eliminating light leakage and fundamentally solving the problem of light leakage in Mini LED beads.

[0037] In specific implementation, S1, mounting several LED chips 4 onto the circuit board 3 includes: S11. Use plasma cleaning or ultrasonic cleaning (deionized water + ethanol) to remove oil, dust and oxides from the surface of circuit board 3. S12. Bake circuit board 3 at 120-130°C for 2 hours to remove moisture and prevent bubbles or delamination during subsequent die bonding. S13. Fix the circuit board 3 on the worktable of the die bonder, and then accurately apply a small amount of die bonder adhesive at the mounting position of the LED chip 4. The die bonder picks up the LED chip 4 from the wafer film and mounts the LED chip 4 onto the adhesive dot with a set pressure (usually 20-100gf). Ensure that the position and angle of the LED chip 4 are accurate. Finally, perform low-temperature curing in the oven (30-60 minutes at 150°C) to completely cure the die bonder adhesive. S14. Form ball solder on the 4 electrodes of the LED chip, and then lead the wire to the pad of the circuit board 3 according to the preset arc trajectory. Finally, form wedge solder or ball solder on the pad and check the arc shape, whether the wire is collapsed or short-circuited through the optical inspection system. S15. After wire bonding, the entire circuit board 3 is subjected to plasma cleaning (oxygen / argon mixture) to remove organic residues and improve the adhesion between the subsequent molding fluorescent adhesive and the circuit board 3 and LED chip 4.

[0038] In one example, after mounting several LED chips 4 onto the circuit board 3, AOI (Automated Optical Inspection) is used to confirm the position of the chips 4 and the quality of the bonding wires. Some LED chips 4 are also tested under low current to confirm that the electrical connection is normal.

[0039] In step S2, a fluorescent colloid 1 is molded and cured on one side of the circuit board 3 where the LED chip 4 is located. The fluorescent colloid 1 covers the LED chip 4. The fluorescent colloid 1 serves two purposes: firstly, it helps the LED emit white light. The fluorescent colloid 1 contains a uniform mixture of phosphors. When the high-energy blue light emitted by the LED chip 4 passes through the fluorescent colloid 1, it excites the phosphors to emit low-energy yellow, red, or green light. These different colors of light eventually mix together to form the white light we see. Secondly, the fluorescent colloid 1 protects the LED chip 4 from external forces and environmental factors, preventing it from being corroded by moisture, physical impacts, and vibrations, thus ensuring its long-term stable operation.

[0040] Furthermore, S2 molds a phosphor colloid 1 without an encapsulation groove on one side of the circuit board 3 where the LED chip 4 is located. This process has lower requirements for molding and lower mold manufacturing costs. Compared to directly molding a phosphor colloid 1 with an encapsulation groove, the LED chip size can be made extremely small, mold maintenance and demolding are easier, costs are lower, mold life is longer, and the groove width precision control of the encapsulation groove is better.

[0041] In specific implementation, S2, a fluorescent colloid 1 is molded and cured on one side of the circuit board 3 where the LED chip 4 is located. The fluorescent colloid 1 covers the LED chip 4, including: S21. Preheat the circuit board 3 completed in S1 at 150°C for 30 to 60 minutes to remove moisture and improve the fluidity of the fluorescent colloid 1. S22. Place the preheated circuit board 3 (light-emitting side up) accurately into the cavity of the molding machine and position it using vacuum adsorption or mechanical clamping. S23. Close the upper mold of the molding press, apply the mold closing pressure with the hydraulic press, and at the same time evacuate the mold cavity to below -0.095MPa, and maintain the evacuation for 5 to 10 seconds to remove air. S24. The degassed liquid fluorescent adhesive is injected into the transfer cylinder inside the molding machine. The hydraulic ejector rod inside the molding machine pushes the liquid fluorescent adhesive 1 through the flow channel to fill the cavity around each chip with a pressure of 0.5 to 5 MPa. S25. Maintain the curing temperature of the molding machine for a period of time to allow the liquid fluorescent colloid 1 to undergo a cross-linking reaction, changing from liquid to solid, while the fluorescent powder is fixed. S26. After demolding, check whether the surface of fluorescent colloid 1 is intact, and whether there are any bubbles or missing material. S26. Place the demolded circuit board 3 into a hot air circulating oven for post-curing to fully cross-link the fluorescent colloid 1, improve the bonding strength and heat resistance, eliminate internal stress, and prevent cracking during subsequent grooving or use. S27. After post-curing, allow it to cool naturally to room temperature. Then, use a lint-free cloth dampened with alcohol to gently wipe the surface to remove any possible residual release agent or dust. Finally, check the surface quality of fluorescent colloid 1, including whether there are cracks, bubbles, dents or foreign objects, as well as the thickness and color uniformity of fluorescent colloid 1.

[0042] The processing method for S3 to process the encapsulation groove surrounding the LED chip 4 on the fluorescent colloid 1 includes any one of laser processing, etching processing, and mechanical processing, with laser processing being preferred. Laser processing has a very small heat-affected zone and high precision, which can maintain the groove width processing accuracy of the encapsulation groove at a high level.

[0043] In one example, the encapsulation groove extends to the circuit board 3. This design allows black protective adhesive to fill the light leakage channel between the LED chip 4 and the PCB board 3 during molding or injection molding, eliminating gaps and preventing light leakage channels from forming below the encapsulation groove. This ensures a reliable, effective, and thorough solution to the Mini LED chip crosstalk problem and guarantees the packaging quality of the LED chip 4.

[0044] In one example, several LED chips 4 are arranged in a rectangular array on the circuit board 3. Preferably, the encapsulation slots are rectangular, with the encapsulation slots of adjacent LED chips 4 partially overlapping. This design facilitates the rapid fabrication of encapsulation slots for each LED chip 4. For instance, multiple equally spaced horizontal and vertical slots can be fabricated on the phosphor colloid 1. These horizontal and vertical slots intersect to form rectangular encapsulation slots, each encapsulating one LED chip 4.

[0045] In specific implementation, taking laser processing as an example, S3, processing the encapsulation groove surrounding the LED chip 4 on the fluorescent colloid 1 includes: S31. Set the slot size, slot width, slot depth and other parameters, and plan the slot path. It should be noted that the encapsulation slot should penetrate the fluorescent colloid 1 until it exposes the surface of the circuit board 3 or the sidewall of the LED chip 4, but the LED chip 4 and the bonding wire should not be damaged. S32. Start the laser and scan line by line according to the set path to ablate fluorescent colloid 1. During the process, turn on the dust removal system (exhaust + filtration) to absorb the smoke and dust generated during ablation. S33. Use a laser confocal microscope or white light interferometer to measure the tank depth and sidewall angle. The tank bottom should be smooth, free of residual colloid, with a sidewall verticality of ≥85° and no obvious melting splashes or carbonized black edges. S34. Use high-pressure deionized water or CO2 snow spray to remove residual dust in the slot, then check and confirm the integrity and positional accuracy of each packaging slot, reject units that have been missed or have poor slot shape, and finally perform a resistance test to ensure that the circuit board 3 wires are not damaged during the slotting process.

[0046] Specifically, such as Figure 2 As shown, the step S4, molding the black adhesive light-shielding frame 2 into the encapsulation groove and curing it, includes: S41. Preheat the reheated black glue cake to 75-85℃ to obtain black glue fluid; S42. Inject the black adhesive fluid into the vacuum molding equipment so that the black adhesive fluid fills the encapsulation tank and the gap between the LED chip 4 and the circuit board 3. S43. Maintain a curing temperature of 150-175°C in the molding equipment for 2-4 minutes until the black glue fluid is cured to form a black glue light-blocking frame 2. S44. After demolding, place the black glue light-blocking frame 2 into the baking equipment for secondary curing. The curing temperature is 120-150℃ and the time is 3-4 hours. S45, Remove the burrs from the black vinyl blackout frame 2.

[0047] By adopting the above technical solution, the black glue light-shielding frame 2 can still be firmly bonded and sealed to the fluorescent glue 1 after curing, eliminating the possibility of gaps between the fluorescent glue 1 and the black glue light-shielding frame 2, as well as between the LED chip 4 and the PCB board 3. This ensures the reliable packaging quality of the LED chip 4, completely eliminates the problem of light leakage in Mini LED beads, improves the contrast and black field effect of LED beads, results in better picture quality, better color consistency, high packaging reliability, and more comprehensive protection for LED chips.

[0048] In one example, the black plastic cake material in S41 is black epoxy molding compound (EMC). Black epoxy molding compound (EMC) is a solid cake-shaped thermosetting material containing a latent curing agent. It must always be stored in a sealed container at a low temperature of 0-10°C to prevent slow cross-linking and moisture absorption at room temperature. Therefore, it needs to undergo two stages of warming before use.

[0049] Phase 1: Restore to room temperature. Remove the sealed EMC cake from the cold storage, keep the packaging sealed, and allow it to stand at room temperature (20-25℃) for 24 hours to allow the temperature inside and outside of the cake to become uniform. If there is any cake left over after a single use, it must be resealed and refrigerated within 72 hours. When taking it out for use again, it must be used within 24 hours after being brought to room temperature.

[0050] The second stage: After opening and dehumidifying, and after 24 hours of warming, open the sealed packaging 1-4 hours before use, and place the material cake in a device purged with dry air or dry nitrogen for humidity stabilization. This step can effectively remove trace amounts of moisture that may have been adsorbed on the surface of the material cake during low-temperature storage, preventing porosity defects caused by moisture vaporization during subsequent high-temperature molding.

[0051] In one example, the preheating method in S41 is high-frequency preheating, which uses a high-frequency electromagnetic field to cause the polar molecules inside the EMC to vibrate and rub at high speed, thereby achieving uniform heating "from the inside out" and rapidly raising the temperature of the cake to the required temperature range.

[0052] It should be noted that the preheated material cake should be soft enough to be easily deformed by pinching with your fingers, but not too soft, which would cause it to collapse and affect subsequent feeding. After being removed from the preheating equipment, the material cake must be transferred to the transfer cylinder of the molding equipment within 10 seconds to prevent the hot material cake from dissipating heat in the air for too long, or the surface of the material cake from rapidly decreasing its fluidity due to cooling, ultimately affecting the molding quality. In addition, during preheating, it is necessary to leave a certain gap between each material cake to ensure that each material cake is heated fully and evenly, preventing pitting defects caused by large temperature differences during encapsulation.

[0053] In one example, before injecting the black glue fluid into the vacuumed molding equipment in S42, a comprehensive inspection of the molding equipment and all preset parameters is carried out, including whether the mold surface is clean, whether there is any residual glue or contaminants, and whether the mold vent is unobstructed, whether the temperature difference in each area of ​​the mold is controlled within the allowable range, and whether the mold closing pressure reaches the set value. After inspection, the circuit board 3 with the S3 packaged groove processed is accurately placed into the cavity of the lower mold of the molding equipment. It is positioned by vacuum adsorption or mechanical clamping. Then the mold is closed and a vacuum is drawn to make the vacuum degree in the cavity reach below -0.095 MPa (i.e. close to a complete vacuum). The vacuum state is maintained for 5 to 10 seconds. The purpose of vacuuming is to completely remove the air in the cavity, prevent the air from interacting with EMC under high temperature and high pressure to produce pores, and avoid high temperature oxidation of sensitive components.

[0054] After vacuuming, the preheated black EMC cake is placed into the transfer cylinder of the molding machine for injection molding. Injection molding must be completed before the EMC gelation time ends. During the injection molding process, pressure is applied to the black EMC cake to fill the encapsulation slot and the gap between the LED chip 4 and the circuit board 3.

[0055] In one example, after the EMC cookie completes the injection and fills all the encapsulation slots and the gap between the LED chip 4 and the circuit board 3 in S43, the molding equipment continues to maintain the mold closed state while keeping the mold temperature in the range of 150 to 175°C, so that the cookie can undergo a cross-linking and curing reaction. The in-mold curing time is 2 to 4 minutes, and the specific time depends on the product size, the depth of the encapsulation slots and the material formulation.

[0056] In one example, the secondary curing after demolding in S44 is an absolutely necessary step in the molding process. The 2-4 minutes of in-mold curing only completes part of the cross-linking reaction of EMC, with a cross-linking degree of about 60-80%. At this time, there are still a large number of unreacted chemical groups inside the material, and its mechanical strength, adhesion and heat resistance are far from optimal. It is necessary to bake it at high temperature a second time to make EMC reach a fully cross-linked state, so as to obtain stable physical and chemical properties.

[0057] Optionally, a secondary curing condition of 120–150℃ for 3–4 hours can be used to achieve complete cross-linking while reducing the impact of high-temperature baking on the color temperature of fluorescent colloid 1.

[0058] Optionally, the secondary curing adopts a stepped curing method, first curing at 80°C for 1 hour, then curing at 120°C for 1 hour, and then raising the temperature to 150°C for 2 hours. This allows the colloid to gradually shrink during the heating process, reducing internal stress and preventing cracking at the microscale.

[0059] Specifically, such as Figure 3 As shown, the process of injection molding and curing the black adhesive light-shielding frame 2 in the encapsulation groove as described in S4 includes: S401. After drying the thermoplastic black rubber material, inject it into the injection molding equipment; S402. The injection molding equipment heats the black rubber material to a melt and then injects it into the encapsulation tank. S403, after holding pressure for a period of time and then curing, the black glue light-blocking frame 2 is obtained.

[0060] By adopting the above technical solution, the LED chip 4 packaging quality can be obtained by injection molding process, which is comparable to that of compression molding process. After the black glue light-shielding frame 2 is cured, it can still be firmly bonded and sealed to the fluorescent glue 1. Compared with compression molding process, injection molding process has lower cost and higher production efficiency, making it very suitable for mass production.

[0061] Optionally, the injection molding equipment injects the black adhesive material into the encapsulation tank at an injection pressure of 80–150 MPa for 0.5–2 seconds; the holding pressure time is 5–15 seconds, and the holding pressure is 80–100% of the injection pressure; the curing process involves cooling the black adhesive material in the encapsulation tank for 20–60 seconds. This design ensures that the injection molding process can also achieve LED chip 4 encapsulation quality comparable to that of the molding process.

[0062] In this embodiment, S5, the black glue light-shielding frame 2 and the circuit board 3 are cut along the center line of the black glue light-shielding frame 2 to obtain LED beads. Due to the high precision of molding and injection molding, the thickness of the black glue light-shielding frame 2 can be made very thin, easily achieving LED bead size below P0.8mm, or even reaching P0.2-P0.3mm.

[0063] In another aspect of the embodiments of this disclosure, an LED lamp bead is provided, such as... Figure 4 and Figure 5 As shown, the LED bead includes: a circuit board 3, a fluorescent colloid 1, and a black adhesive light-shielding frame 2. An LED chip 4 is disposed on one side of the circuit board 3. The fluorescent colloid 1 is tightly bonded to the side of the circuit board 3 where the LED chip 4 is disposed, and the LED chip 4 is located inside the fluorescent colloid 1. The black adhesive light-shielding frame 2 is embedded in the fluorescent colloid 1 and surrounds the LED chip 4; the black adhesive light-shielding frame 2 and the fluorescent colloid 1 are tightly connected. With this design, the black protective adhesive and the fluorescent colloid 1 in the LED bead are tightly bonded together and fill the light leakage channel between the LED chip 4 and the PCB board 3, eliminating gaps and thus solving the light leakage problem of Mini LED beads. Furthermore, the black protective adhesive obtained by injection molding or compression molding is thin, further reducing the size of the LED bead.

[0064] In one example, such as Figure 4 and Figure 5 As shown, the upper surface of the black adhesive light-shielding frame 2 is flush with the outer surface of the fluorescent colloid 1, and the lower surface of the black adhesive light-shielding frame 2 is in close contact with the circuit board 3. This design allows the black adhesive light-shielding frame 2 to penetrate into the light leakage channel between the LED chip 4 and the PCB board 3, eliminating gaps and light leakage dead angles.

[0065] In another aspect of the present disclosure, an LED module is provided, including LED beads.

[0066] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0067] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for packaging LED chips, characterized in that, include: Several LED chips are mounted onto a circuit board; A fluorescent colloid is molded and cured on one side of the circuit board where the LED chip is located, and the fluorescent colloid covers the LED chip. Encapsulation grooves that wrap around LED chips are fabricated on fluorescent colloids; The black adhesive light-shielding frame is molded or injection molded into the encapsulation groove and then cured. Cut the black vinyl light-blocking frame and circuit board along the center line of the black vinyl light-blocking frame.

2. The LED chip packaging method according to claim 1, characterized in that: The encapsulation slot extends to the circuit board.

3. The LED chip packaging method according to claim 1, characterized in that: Several LED chips are arranged in a rectangular array on a circuit board. The encapsulation slots are rectangular, and the encapsulation slots of two adjacent LED chips partially overlap.

4. The LED chip packaging method according to claim 1, characterized in that: The process of molding and curing the black adhesive light-shielding frame in the encapsulation groove includes: The cooled black rubber cake is preheated to 75-85℃ to obtain black rubber fluid. The black adhesive fluid is injected into a vacuum molding device to fill the encapsulation tank and the gap between the LED chip and the circuit board. Maintain a curing temperature of 150-175°C inside the molding equipment for 2-4 minutes until the black glue fluid solidifies, forming a black glue light-blocking frame. After demolding, place the black glue light-blocking frame into the baking equipment for secondary curing. The curing temperature is 120-150℃ and the time is 3-4 hours. Remove the burrs from the black vinyl frame.

5. The LED chip packaging method according to claim 1, characterized in that: The process of injection molding and curing the black adhesive light-shielding frame in the encapsulation groove includes: The thermoplastic black rubber material is dried and then injected into the injection molding equipment; The injection molding equipment heats the black rubber material to a melt and then injects it into the encapsulation tank; After being held under pressure for a period of time, a curing process is performed to obtain a black glue light-blocking frame.

6. The LED chip packaging method according to claim 5, characterized in that: The injection molding equipment injects the black rubber material into the encapsulation tank at an injection pressure of 80-150 MPa and an injection time of 0.5-2 seconds. The holding time is 5 to 15 seconds, and the holding pressure is 80 to 100% of the injection pressure. The curing process involves cooling the black adhesive material in the encapsulation tank for 20 to 60 seconds.

7. The LED chip packaging method according to claim 1, characterized in that: The processing method for creating the encapsulation groove surrounding the LED chip on the fluorescent colloid is any one of laser processing, etching processing, or machining.

8. An LED chip obtained using the LED chip packaging method according to any one of claims 1-7, characterized in that, include: The circuit board has LED chips on one side. A fluorescent colloid is tightly bonded to the side of a circuit board where LED chips are located, with the LED chips located inside the fluorescent colloid. A black vinyl light-shielding frame is embedded in a fluorescent colloid and surrounds the LED chip, with the black vinyl light-shielding frame and the fluorescent colloid being tightly connected.

9. The LED lamp bead according to claim 8, characterized in that: The upper surface of the black vinyl light-shielding frame is flush with the outer surface of the fluorescent adhesive, and the lower surface of the black vinyl light-shielding frame is in close contact with the circuit board.

10. An LED module, characterized in that: Includes the LED beads of claim 8 or 9.

Images