LED lamp bead and preparation method thereof

Abstract

The invention discloses an LED lamp bead and a preparation method thereof.The LED lamp bead comprises a support, a chip located on the support, a fluorescent diaphragm attached to the light-emitting side of the chip, transparent silica gel, a supporting ring and white glue, electrodes of the chip are connected with corresponding pins of a PCB of the support through welding wires, the transparent silica gel is located on the side face of the chip and used for connecting the chip and the fluorescent diaphragm, and the supporting ring is connected with the supporting ring through the white glue; the LED lamp bead is characterized in that the LED lamp bead is provided with a chip and a bonding wire, the chip is provided with a fluorescent diaphragm, the supporting ring is located outside the chip and surrounds the chip, the space between the supporting ring and the chip is coated with transparent silica gel, and the chip, the fluorescent diaphragm, the transparent silica gel, the supporting ring and the bonding wire are wrapped with the white glue. The LED lamp bead is provided with the supporting ring prefabricated by the transparent silica gel, and the supporting ring is used for supporting the bonding wire when the chip is combined with the fluorescent diaphragm; the welding wire is prevented from being broken when the transparent silica gel is coated, and the welding wire is enabled to extend towards the direction of the position of the support, thereby facilitating the connection between the welding wire and the corresponding pin of the support PCB.

Description

Technical Field

[0001] The present invention relates to the technical field of LED lamps, and in particular to an LED lamp bead and a preparation method thereof. Background Art

[0002] LED lamps emit light by energizing semiconductor chips. The preparation of LED lamp beads includes the following processes: the LED chip is cured to the bracket through silver glue or white glue, and then the chip electrodes and the pins of the circuit board are connected with welding wires. The chip is sealed with epoxy resin around, and finally the shell is installed. The color of the light source is converted by encapsulating phosphor inside the LED lamp bead to achieve a wider range of color temperature and color output, especially for producing white light LEDs.

[0003] The packaging methods of phosphors include the phosphor dot process and the phosphor spray process. In these two processes, if the phosphors are unevenly distributed on the LED chip, uneven light spots will appear, affecting the light quality of the LED lamp. Patent CN109273579B proposes a method for preparing LED lamp beads, attaching a fluorescent film to the LED chip instead of the phosphor packaging process to ensure that the phosphors are evenly distributed on the LED chip. However, during the preparation process, transparent silicone needs to be coated on the side of the chip to connect the chip and the fluorescent film. The transparent silicone wrapped on the side of the chip is not conducive to the welding wire of the chip electrode, and it is not convenient to make electrical connections between the chip and the bracket. Summary of the invention

[0004] Aiming at the problem in the prior art that when the chip and the fluorescent film are bonded together, transparent silicone wrapped around the side of the chip is not conducive to the welding wire of the chip electrode, the present invention proposes an LED lamp bead and a preparation method thereof, which facilitates the welding wire between the chip electrode and the circuit board pin on the bracket.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] An LED lamp bead includes a bracket, a chip located on the bracket, and a fluorescent film attached to the light-emitting side of the chip, wherein the electrodes of the chip are connected to corresponding pins of a bracket PCB board through welding wires. The LED lamp bead also includes transparent silicone, a support ring, and white glue. The transparent silicone is located on the side of the chip and is used to connect the chip and the fluorescent film. The support ring is located outside the chip and surrounds the chip, and a glue-containing space for accommodating part of the transparent silicone is formed between the support ring and the chip, and the welding wire has a contact point with the support ring. The white glue is located outside the chip and wraps the chip, the fluorescent film, the transparent silicone, the support ring, and the welding wire.

[0007] Preferably, the LED lamp bead also includes a lens connected to the bracket, and the fluorescent film and white glue are located inside the lens.

[0008] The present invention also proposes two preparation methods based on the above-mentioned LED lamp beads.

[0009] The first method for preparing an LED lamp bead comprises the following steps:

[0010] Step 1: Solder the first end of the wire to the two electrodes of the chip:

[0011] Step 2: prepare a fluorescent film, keep the two surfaces of the fluorescent film sticky, stick a high temperature resistant support film on the first surface of the fluorescent film, and place a support ring on the second surface;

[0012] Step 3: attach the light-emitting side of the chip to the second surface of the fluorescent film, keep the chip inside the support ring so that the support ring supports the welding wire, and the second end of the welding wire extends away from the fluorescent film;

[0013] Step 4: Apply transparent silicone between the chip and the support ring and solidify it. The part of the transparent silicone that is higher than the support ring is fixed to the surrounding of the LED chip in an arc shape, and the welding wire extends from the transparent silicone.

[0014] Step 5: cutting along the first grooves between the chips to obtain a single first chip body with a fluorescent film;

[0015] Step 6: Fix the first chip body with the fluorescent film on the surface of the bracket, keep the side of the first chip body attached to the fluorescent film facing upward, and weld the second end of the welding wire to the corresponding pin of the bracket PCB board;

[0016] Step 7: Fill white glue between adjacent first chip bodies and solidify it, keeping the height of the white glue no higher than the upper surface of the fluorescent film;

[0017] Step eight: cutting along the second grooves between the first chip bodies to obtain the second chip bodies after wiring.

[0018] Preferably, the method for preparing the first LED lamp bead further includes step nine, pressing a lens wrapped with a fluorescent film on a bracket of the second chip body to obtain a target LED lamp bead.

[0019] Preferably, in step 2, the fluorescent film inside the support ring is kept wrinkle-free.

[0020] Preferably, in step 2, the method for preparing the fluorescent film comprises the following steps: step A1, forming a first colloid by mixing fluorescent powder and transparent silica gel; step A2, coating the first colloid on a support film, and baking and drying the first colloid to obtain a fluorescent film on the support film.

[0021] Preferably, the baking temperature of the first colloid is 70-80° C., and the baking time is 25-35 min.

[0022] The second method for preparing LED lamp beads comprises the following steps:

[0023] Step B1: Fix the chip on the upper surface of the bracket, keep the light-emitting side of the chip facing upward, and connect the corresponding pins of the bracket PCB board with the electrodes of the chip through welding wires;

[0024] Step B2: cutting along the third grooves between the chips to obtain a third chip body after wiring;

[0025] Step B3: preparing a fluorescent film, keeping the two surfaces of the fluorescent film sticky, attaching a high temperature resistant support film to the first surface of the fluorescent film, and placing a support ring on the second surface;

[0026] Step B4: Invert the third chip body with the light-emitting side of the chip facing downward, and attach the light-emitting side of the chip to the second surface of the fluorescent film, keeping the chip inside the support ring so that the support ring supports the welding wire;

[0027] Step B5: Coating transparent silicone between the chip and the support ring and curing the silicone, wherein the portion of the transparent silicone higher than the support ring is fixed to the periphery of the LED chip in an arc shape;

[0028] Step B6: cutting along the fourth grooves between the chips to obtain a single fourth chip body with a fluorescent film;

[0029] Step B7: Apply white glue on the bracket of the fourth chip body and solidify it, and keep the height of the white glue no higher than the upper surface of the fluorescent film.

[0030] Preferably, the method for preparing the second LED lamp bead further includes step B8, pressing a lens wrapped with a fluorescent film on a bracket of the fourth chip body to obtain a target LED lamp bead.

[0031] The beneficial effects of the present invention are:

[0032] 1. The LED lamp bead in the present invention is provided with a support ring prefabricated with transparent silicone, and the support ring is used to support the welding wire when the chip is combined with the fluorescent film to prevent the welding wire from being damaged when the transparent silicone is coated, and at the same time, the welding wire is extended in the direction of the position of the bracket, which is convenient for connecting the welding wire with the corresponding pin of the bracket PCB board; moreover, the support ring can limit the position of the transparent silicone coating to avoid overflow during the transparent silicone coating.

[0033] 2. In the preparation process of the LED lamp beads in the present invention, the electrodes of the chip are connected by welding wires before transparent silicone is coated on the side of the chip, and then the welding wires are supported by a support ring to prevent the welding wires from being damaged when the transparent silicone is coated. At the same time, the welding wires are extended in the direction of the position of the bracket, which is convenient for connecting the welding wires with the corresponding pins of the bracket PCB board. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic diagram of the structure of the LED lamp bead; Figure 2 This is a schematic diagram of the structure of the chip in step C1 of the LED lamp bead preparation method; Figure 3 This is a schematic diagram of the structure of the fluorescent film in step C3 of the LED lamp bead preparation method; Figure 4 This is a schematic diagram of the structure of the chip and the fluorescent film combined in step C4 of the LED lamp bead preparation method; Figure 5 This is a schematic diagram of the structure of coating transparent silicone in step C5 of the LED lamp bead preparation method; Figure 6 This is a schematic diagram of the structure of the first chip body in step C6 of the LED lamp bead preparation method; Figure 7 This is a schematic diagram of the structure of the combination of the first chip body and the bracket in step C7 of the LED lamp bead preparation method; Figure 8 This is a schematic diagram of the structure of coating white glue in step C8 of the LED lamp bead preparation method; Fig. 9 This is a schematic diagram of the structure of the second chip body in step C9 of the LED lamp bead preparation method; Fig.10 This is a schematic diagram of the structure of the welding wire connection in step B1 of the LED lamp bead preparation method; Fig.11 This is a schematic diagram of the structure of the third chip body in step B2 of the LED lamp bead preparation method; Fig.12 This is a schematic diagram of the structure of the combination of the third chip body and the fluorescent film in step B5 of the LED lamp bead preparation method; Fig.13 This is a schematic diagram of the structure of the fourth chip body in step B6 of the LED lamp bead preparation method.

[0047] In the figure: 1. bracket; 2. chip; 3. fluorescent film; 4. transparent silicone; 5. support ring; 6. welding wire; 7. white glue; 8. lens. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0049] Example 1

[0050] refer to Figure 1 , an LED lamp bead, including a bracket 1 and a chip 2, the chip 2 is located above the bracket 1, the chip 2 and the bracket 1 are connected by curing with silver glue, and the electrodes of the chip 2 are connected to the corresponding pins of the PCB board of the bracket 1 through welding wires 6. The chip 2 is above the light-emitting side of the chip 2, and a fluorescent film 3 is attached above the chip 2, and the fluorescent film 3 and the chip 2 are connected by transparent silicone 4. The area of ​​the fluorescent film 3 is larger than the area of ​​the chip 2, and the edge of the fluorescent film 3 extends from the upper part of the chip 2. The transparent silicone 4 is coated on the side of the chip 2 to connect the fluorescent film 3.

[0051] A support ring 5 is also provided between the fluorescent diaphragm 3 and the bracket 1. The support ring 5 is located outside the chip 2 and surrounds the chip 2. The support ring 5 is in contact with the fluorescent diaphragm 3. A space for accommodating transparent silicone 4 is formed between the support ring 5 and the chip 2. The transparent silicone 4 is located below the fluorescent diaphragm 3. The support ring 5 can limit the coating position of the transparent silicone 4 to avoid overflow when the transparent silicone 4 is coated. The welding wire 6 has a contact point with the support ring 5. The support ring 5 is used to support the welding wire when the chip is combined with the fluorescent diaphragm to avoid the welding wire being damaged when the transparent silicone is coated. At the same time, the welding wire is extended in the direction of the bracket, which is convenient for connecting the welding wire with the corresponding pin of the bracket PCB board.

[0052] The LED lamp bead also includes white glue 7, which is a high-reflectivity white glue used to improve the utilization rate of the LED lamp bead light and enhance the brightness. The white glue 7 is located outside the chip 2 and wraps the chip 2, the fluorescent film 3, the transparent silica gel 4, the support ring 5 and the welding wire 6. The white glue 7 is used to reflect the light of the chip 2. The position of the white glue 7 is not higher than the upper surface of the fluorescent film 3 to avoid the white glue 7 from shading.

[0053] The LED lamp bead also includes a lens 8 , which is a cover body. The bottom of the lens 8 is connected to the bracket 1 , and the fluorescent film 3 and the white glue 7 are located inside the lens 8 . The lens 8 is used to protect the chip 2 and the fluorescent film 3 .

[0054] Example 2

[0055] This embodiment provides a method for preparing the LED lamp bead in Embodiment 1, comprising the following steps:

[0056] Step C1: Reference Figure 2 , first ends of the bonding wires 6 are respectively welded to the two electrodes of the chip 2 .

[0057] Step C2: preparing the fluorescent film 3. The preparation method of the fluorescent film 3 includes the following steps. In the first step, the fluorescent powder and transparent silica gel are mixed to form a first colloid, and the ratio of transparent silica gel to fluorescent powder is maintained at 1:2; in the second step, the first colloid is coated on the support film with a coating thickness of 150 μm. After the first colloid is baked and dried, the fluorescent film 3 is obtained on the support film. The baking temperature of the first colloid is 75°C and the baking time is 30 minutes. After baking and drying, the fluorescent film 3 with sticky surfaces on both sides is obtained.

[0058] Step C3: Reference Figure 3 A support ring 5 is placed on the second surface of the fluorescent film 3. The support ring 5 is prefabricated with transparent silica gel and is light-transmissive. When the support ring 5 is placed, the fluorescent film 3 inside the support ring 5 is kept wrinkle-free.

[0059] Step C4: Reference Figure 4 , attach the light-emitting side of the chip 2 to the second surface of the fluorescent film 3, and keep the chip 2 inside the support ring 5. The support ring 5 can support the welding wire 6 so that the second end of the welding wire 6 extends away from the fluorescent film 3, which is convenient for connecting the welding wire 6 with the corresponding pin of the PCB board on the bracket 1.

[0060] Step C5: Reference Figure 5 , a transparent silicone 4 is coated between the chip 2 and the support ring 5 and cured, the transparent silicone 4 can seal and fix the first end of the welding wire 6, and the second end of the welding wire 6 extends from the transparent silicone 4; when the transparent silicone 4 is coated, the part of the transparent silicone 4 higher than the support ring 5 is fixed to the surrounding of the LED chip in an arc shape, and when the white glue 7 is coated, an arc surface with an opening toward the light-emitting side of the LED chip can be formed outside the chip 2, which is beneficial to the reflection of light from the LED chip.

[0061] Step C6: A first groove for regulating the area of ​​the fluorescent film 3 is provided on the support film, and cutting is performed along the first groove between the chips 2, referring to Figure 6 , obtaining a single first chip body with a fluorescent film 3;

[0062] Step C7: Reference Figure 7 , fix the first chip body with the fluorescent film 3 on the surface of the bracket 1, the first chip body and the bracket 1 are connected by curing with silver glue, and keep the side of the first chip body attached to the fluorescent film 3 facing upward, and weld the second end of the welding wire 6 to the corresponding pin of the PCB board of the bracket 1;

[0063] Step C8: Reference Figure 8 , fill white glue 7 between adjacent first chip bodies and solidify it, keeping the upper surface of the white glue 7 and the upper surface of the fluorescent film 3 at the same horizontal position; the white glue 7 is in contact with the transparent silicone 4 and the support ring 5, forming an arc surface outside the chip 2 with an opening toward the light-emitting side of the LED chip.

[0064] Step C9: A second groove is provided on the bracket to regulate the area of ​​the bracket 1, referring to Fig. 9 , cutting is performed along the second grooves between the first chip bodies to obtain the second chip bodies after wiring.

[0065] Step C10, reference Figure 1 , a lens 8 wrapped with a fluorescent film 3 and white glue 7 is pressed on the bracket 1 of the second chip body to obtain a target LED lamp bead.

[0066] Example 3

[0067] This embodiment proposes a method for preparing an LED lamp bead that is different from that of Embodiment 2. The method for preparing an LED lamp bead is used to prepare the LED lamp bead in Embodiment 1, and comprises the following steps:

[0068] Step B1: Reference Fig.10 , fix the chip 2 on the upper surface of the bracket 1, keep the light-emitting side of the chip 2 facing upward, and connect the corresponding pins of the PCB board of the bracket 1 with the electrodes of the chip 2 through the welding wire 6;

[0069] Step B2: A third groove is provided on the bracket to regulate the area of ​​the bracket 1, referring to Fig.11 , cutting along the third grooves between the chips 2 to obtain a third chip body after wiring;

[0070] Step B3: Prepare the fluorescent film 3. The preparation method of the fluorescent film 3 includes the following steps. The first step is to form a first colloid by mixing the fluorescent powder and transparent silica gel, and keep the ratio of transparent silica gel to fluorescent powder at 1:2; the second step is to coat the first colloid on the support film with a coating thickness of 150μm. After the first colloid is baked and dried, the fluorescent film 3 is obtained on the support film. The baking temperature of the first colloid is 75℃ and the baking time is 30min. After baking and drying, a fluorescent film 3 with sticky surfaces on both sides is obtained;

[0071] A support ring 5 is placed on the second surface of the fluorescent film 3. The support ring 5 is prefabricated with transparent silica gel and is light-transmissive. When placing the support ring 5, the fluorescent film 3 inside the support ring 5 is kept wrinkle-free.

[0072] Step B4: Invert the third chip body, with the light-emitting side of the chip 2 facing downward, and attach the light-emitting side of the chip 2 to the second surface of the fluorescent film 3, keeping the chip 2 inside the support ring 5, which can support the welding wire 6 to avoid kinking of the welding wire 6 when coating the transparent silicone 4;

[0073] Step B5: Reference Fig.12 , a transparent silicone rubber 4 is coated between the chip 2 and the support ring 5 and cured, and the portion of the transparent silicone rubber 4 that is higher than the support ring 5 is fixed to the periphery of the LED chip in an arc shape;

[0074] Step B6: A fourth groove is provided on the support film to regulate the area of ​​the fluorescent film 3, referring to Fig.13 , cutting is performed along the fourth grooves between the chips 2 to obtain a single fourth chip body with a fluorescent film 3;

[0075] Step B7: coating white glue 7 on the bracket 1 of the fourth chip body and curing it, keeping the upper surface of the white glue 7 and the upper surface of the fluorescent film 3 at the same horizontal position; the white glue 7 is in contact with the transparent silica gel 4 and the support ring 5, forming an arc surface outside the chip 2 with an opening toward the light-emitting side of the LED chip;

[0076] Step B8, pressing the lens 8 wrapped with the fluorescent film 3 and the white glue 7 on the bracket 1 of the fourth chip body to obtain the target LED lamp bead.

[0077] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An LED lamp bead, comprising a bracket (1), a chip (2) located on the bracket (1) and a fluorescent film (3) attached to the light-emitting side of the chip (2), wherein the electrodes of the chip (2) are connected to corresponding pins of a PCB board of the bracket (1) through welding wires (6), characterized in that: Also includes: A transparent silica gel (4) located on the side of the chip (2) and used to connect the chip (2) and the fluorescent film (3); a support ring (5) located outside the chip (2) and surrounding the chip (2), wherein a space for accommodating a portion of the transparent silica gel (4) is formed between the support ring (5) and the chip (2), and the welding wire (6) has a contact point for contacting the support ring (5); and A white glue (7) is located outside the chip (2) and wraps the chip (2), the fluorescent film (3), the transparent silica gel (4), the support ring (5) and the welding wire (6).

2. The LED lamp bead according to claim 1, characterized in that: It also comprises a lens (8) connected to the bracket (1), and the fluorescent film (3) and the white glue (7) are located inside the lens (8).

3. A method for preparing the LED lamp bead according to claim 1, characterized in that: The following steps are involved: Step 1: Weld the first ends of the welding wires (6) to the two electrodes of the chip (2) respectively: Step 2: prepare a fluorescent film (3), keep the two surfaces of the fluorescent film (3) sticky, stick a high-temperature resistant support film on the first surface of the fluorescent film (3), and place a support ring (5) on the second surface; Step 3: attach the light-emitting side of the chip (2) to the second surface of the fluorescent film (3), keep the chip (2) inside the support ring (5) so that the support ring (5) supports the welding wire (6), and the second end of the welding wire (6) extends in a direction away from the fluorescent film (3); Step 4: a transparent silicone rubber (4) is coated between the chip (2) and the support ring (5) and cured, wherein the portion of the transparent silicone rubber (4) higher than the support ring (5) is fixed to the periphery of the LED chip in an arc shape, and a welding wire (6) extends from the transparent silicone rubber (4); Step 5: cutting along the first grooves between the chips (2) to obtain a single first chip body with a fluorescent film (3); Step 6: Fix the first chip body with the fluorescent film (3) on the surface of the bracket (1), keep the side of the first chip body attached to the fluorescent film (3) facing upward, and weld the second end of the welding wire (6) to the corresponding pin of the PCB board of the bracket (1); Step 7: Filling white glue (7) between adjacent first chip bodies and curing the white glue (7) to ensure that the height of the white glue (7) is not higher than the upper surface of the fluorescent film (3); Step eight: cutting along the second grooves between the first chip bodies to obtain the second chip bodies after wiring.

4. The method for preparing the LED lamp bead according to claim 3, characterized in that: The method further comprises a ninth step of pressing a lens (8) wrapping a fluorescent film (3) on a support (1) of a second chip body to obtain a target LED lamp bead.

5. The method for preparing the LED lamp bead according to claim 3 or 4, characterized in that: In the second step, the fluorescent film (3) inside the supporting ring (5) is kept free of wrinkles.

6. The method for preparing the LED lamp bead according to claim 5, characterized in that: In the step 2, the method for preparing the fluorescent film (3) comprises the following steps: Step A1: forming a first colloid by mixing fluorescent powder and transparent silica gel; Step A2: coating the first colloid on the support film, and baking and drying the first colloid to obtain a fluorescent film (3) on the support film.

7. The method for preparing the LED lamp bead according to claim 6, characterized in that: The baking temperature of the first colloid is 70-80° C., and the baking time is 25-35 minutes.

8. A method for preparing the LED lamp bead according to claim 1, characterized in that: The following steps are involved: Step B1: fix the chip (2) on the upper surface of the bracket (1), keep the light-emitting side of the chip (2) facing upward, and connect the corresponding pins of the PCB board of the bracket (1) to the electrodes of the chip (2) through welding wires (6); Step B2: cutting along the third grooves between the chips (2) to obtain a third chip body after wiring; Step B3: preparing a fluorescent film (3), keeping the two surfaces of the fluorescent film (3) sticky, attaching a high temperature resistant support film to the first surface of the fluorescent film (3), and placing a support ring (5) on the second surface; Step B4: invert the third chip body, with the light-emitting side of the chip (2) facing downward, and attach the light-emitting side of the chip (2) to the second surface of the fluorescent film (3), keeping the chip (2) located inside the support ring (5) so that the support ring (5) supports the welding wire (6); Step B5: coating transparent silicone (4) between the chip (2) and the support ring (5) and curing the coating, wherein the portion of the transparent silicone (4) higher than the support ring (5) is fixed to the periphery of the LED chip in an arc shape; Step B6: cutting along the fourth grooves between the chips (2) to obtain a single fourth chip body with a fluorescent film (3); Step B7: coating white glue (7) on the support 1 of the fourth chip body and curing it, keeping the height of the white glue (7) no higher than the upper surface of the fluorescent film (3).

9. The method for preparing the LED lamp bead according to claim 8, characterized in that: The method further comprises step B8, wherein a lens (8) wrapping a fluorescent film (3) is pressed onto a support (1) of a fourth chip body to obtain a target LED lamp bead.

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