A method for preparing a white LED fluorescent film package

Abstract

This invention provides a method for preparing a white LED phosphor film encapsulation. Red phosphor, green phosphor, diffusing powder, anti-precipitation powder, and silicone adhesive are prepared in preset quantities. Using an improved encapsulation process, the red and green phosphor films are encapsulated and covered above the blue LED chip in a bowl-shaped container, thereby fully stimulating the luminescent characteristics of the two phosphor films. Under the three-primary-color principle, a white output light effect is obtained. This method eliminates the need for excessive phosphor usage, effectively saving phosphor deposited on the sides of conventional LED chips, and fully utilizing the front-side light emission efficiency. While meeting the LED brightness enhancement requirements, it reduces phosphor usage and power consumption, achieving cost reduction while improving brightness. Furthermore, the separate phosphor film fabrication process ensures better film uniformity, effectively guaranteeing the light emission quality and product yield of the LED chips, thus benefiting the industrial efficiency of mass production.

Description

Technical Field

[0001] This invention belongs to the field of LED packaging manufacturing technology, specifically relating to a method for preparing a white LED phosphor film package. Background Technology

[0002] With the development of semiconductor technology, LED devices are being used in a wider range of fields. Backlighting occupies an important share in the LED industry, and competition in the backlight packaging field is fierce. In order to adapt to market demands, the LED industry continues to improve brightness and reduce costs to meet user needs.

[0003] Existing technologies for designing brightness enhancement structures for LED devices typically rely on increasing phosphor and power output as the main solutions. This approach increases the amount of phosphor used and the power consumption, failing to meet cost reduction requirements while improving brightness, which is detrimental to the industrial efficiency of mass production. Furthermore, increasing the amount of phosphor used can easily interfere with the uniformity of light output, affecting the light output quality of LED chips and product yield. Therefore, it is necessary to design a new technical solution to improve this approach. Summary of the Invention

[0004] To address the problems in the prior art, this invention provides a method for preparing a white LED phosphor film package. While meeting the requirements for improving LED brightness, it reduces the amount of phosphor used and the power consumption, thus meeting the cost reduction requirements while improving brightness, and ensuring the light output quality and product yield of the LED beads, thereby facilitating the industrial benefits of mass production.

[0005] This invention is implemented through the following technical solution: a method for preparing a white LED phosphor film encapsulation, comprising the following steps:

[0006] S1: Prepare red powder, green powder, diffusion powder, anti-settling powder, and silicone adhesive according to the preset amount;

[0007] S2: Take 95-105 parts of silica gel, 15-20 parts of red powder, 2-3 parts of diffusion powder, and 1-2 parts of anti-precipitation powder, mix them, stir and pour them into a molding machine to form a red fluorescent film;

[0008] S3: Take 95-105 parts of silica gel, 15-20 parts of green powder, 2-3 parts of diffusion powder, and 1-2 parts of anti-precipitation powder, mix them, stir and pour them into a molding machine to form a green fluorescent film;

[0009] S4: The blue LED chip is fixed inside the cup using a die bonder. Then, a green fluorescent film is placed on top of the blue LED chip using the die bonder. Next, a red fluorescent film is placed on top of the green fluorescent film using the die bonder. The mixture is then baked and cured. Transparent silicone is filled into the gaps inside the cup to complete the encapsulation.

[0010] Furthermore, both the red powder and the green powder are fluorescent powders.

[0011] Furthermore, the diffusion powder contains spherical fine powder of organosilicon resin.

[0012] Furthermore, the organosilicon resin spherical fine powder is a pure white, regular spherical fraction.

[0013] Furthermore, the average particle size of the organosilicon resin spherical fine powder is 1.8–2.2 μm.

[0014] Furthermore, the anti-precipitation powder contains one or more of silicon dioxide, natural sodium-based, and calcium-based bentonite.

[0015] Furthermore, the average particle size of the anti-precipitation powder is 1.8–2.2 μm.

[0016] The beneficial effects of this invention are as follows: By utilizing an improved packaging process, red and green fluorescent films are encapsulated and covered above the blue LED chip in a cup, thereby fully stimulating the luminescent characteristics of the two fluorescent films and obtaining white output light effect under the three-primary-color principle. This method does not require an excessive amount of phosphor, effectively saving phosphor deposited on the side of conventional LED chips, and can fully utilize the front light output efficiency. While meeting the LED brightness improvement requirements, it reduces phosphor usage and power consumption, meeting the cost reduction requirements while improving brightness. Furthermore, the process of separately manufacturing the fluorescent film ensures better film uniformity, effectively guaranteeing the light output quality and product yield of the LED chips, thus benefiting the industrial efficiency of mass production. Attached Figure Description

[0017] Figure 1 This is an initial solidification state diagram according to an embodiment of the present invention;

[0018] Figure 2 This is a diagram showing the state of a single-layer coating according to an embodiment of the present invention;

[0019] Figure 3 This is a diagram showing the state of a two-layer coating according to an embodiment of the present invention;

[0020] Figure 4 This is a dispensing state diagram according to an embodiment of the present invention.

[0021] In the diagram: 10-bowl, 10a-blue light chip, 11-green fluorescent film, 12-red fluorescent film, 13-transparent silicone. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0023] Example 1

[0024] A method for preparing a white LED phosphor film encapsulation includes the following steps:

[0025] S1: Prepare fluorescent red powder, fluorescent green powder, diffusion powder, anti-precipitation powder, and silicone adhesive according to the preset amount;

[0026] The diffusion powder contains spherical fine powder of organosilicon resin. The spherical fine powder of organosilicon resin is a pure white, regular spherical fraction with an average particle size of 2 μm. It is used to promote the uniform diffusion of red or green powder in silicone glue.

[0027] The anti-precipitation powder contains silica, natural sodium-based and calcium-based bentonite, with an average particle size of 2µm. Utilizing the swelling and solubility of bentonite, when dissolved in silicone glue, it can keep the red or green powder stable in various areas of the glue without precipitation. With the assistance of the diffusion powder, it ensures that the red or green powder forms a uniform and stable diffusion state in the solvent.

[0028] S2: Mix 100 parts silica gel, 18 parts red powder, 2.5 parts diffusing powder, and 1.5 parts anti-precipitation powder. After stirring, pour the mixture into a molding machine and mold it to form a red fluorescent film. Due to the auxiliary effect of the diffusing powder and anti-precipitation powder, the red fluorescent film can form a uniform red light emitting surface.

[0029] S3: Mix 100 parts silica gel, 18 parts green powder, 2.5 parts diffusing powder, and 1.5 parts anti-precipitation powder. After stirring, pour the mixture into a molding machine and mold it to form a green fluorescent film. Due to the auxiliary effect of the diffusing powder and anti-precipitation powder, the green fluorescent film can form a uniform green light-emitting surface.

[0030] S4: As Figure 1 As shown, a blue LED chip is bonded into a bowl using a die bonder, and then a green phosphor film is placed on top of the blue LED chip using the same die bonder, forming a structure as shown. Figure 2 As shown in the diagram, a red fluorescent film is then applied over the green fluorescent film using a die bonder, forming a structure as shown in the diagram. Figure 3 As shown, after baking and curing, the gaps inside the bowl / cup are filled with transparent silicone to complete the encapsulation, forming a shape as shown. Figure 4As shown, with the blue LED chip in operation, the blue light output passes through the red and green phosphor films sequentially, stimulating the photoluminescence effect of the phosphors in the films and outputting red and green light respectively. Therefore, based on the three-primary-color principle of blue, red, and green light, an upward-radiating white light output effect is obtained at the cup. Furthermore, the uniform output of the white light effect is ensured with the assistance of transparent silicone. Because the two films are in close contact with the blue LED chip to block blue light, only a small amount of phosphor is needed to mix and form a white light effect. This method eliminates the need for excessive phosphor usage, effectively saving phosphor deposited on the sides of conventional LED chips, and fully utilizing the front light output efficiency. While meeting the requirements for LED brightness enhancement, it reduces phosphor usage and power consumption, achieving cost reduction while increasing brightness. Moreover, the separate manufacturing process of the phosphor film ensures better film uniformity, effectively guaranteeing the light output quality and product yield of the LED chips, thus benefiting the industrial efficiency of mass production.

[0031] Example 2

[0032] The difference between this embodiment and Embodiment 1 lies in changing the proportions of various powders, making it suitable for low-power, chip, or mini LED light-emitting operations. The steps include:

[0033] S1: Prepare fluorescent red powder, fluorescent green powder, diffusion powder, anti-precipitation powder, and silicone adhesive according to the preset amount;

[0034] The diffusion powder contains organosilicon resin spherical fine powder, which is a pure white, regular spherical fraction with an average particle size of 1.8 μm.

[0035] The anti-precipitation powder contains silica, natural sodium-based and calcium-based bentonite, and its average particle size is 1.8 μm.

[0036] S2: Take 105 parts silica gel, 15 parts red powder, 2 parts diffusion powder, and 1 part anti-precipitation powder, mix them, stir and pour them into a molding machine to form a red fluorescent film.

[0037] S3: Take 105 parts silica gel, 15 parts green powder, 2 parts diffusion powder, and 1 part anti-precipitation powder, mix them, stir and pour them into a molding machine to form a green fluorescent film.

[0038] S4: The low-power blue light chip is fixed into the cup using a die bonder. Then, a green fluorescent film is placed on top of the blue light chip using the die bonder. Next, a red fluorescent film is placed on top of the green fluorescent film using the die bonder. The film is then baked and cured. The gaps inside the cup are filled with transparent silicone to complete the encapsulation. Because the phosphor concentration of the film is low, white light output efficiency suitable for energy saving and low power can be obtained through the three primary color principle.

[0039] Example 3

[0040] The difference between this embodiment and Embodiment 1 lies in changing the proportions of various powders, making it suitable for high-power chips or lighting LEDs. The steps include:

[0041] S1: Prepare fluorescent red powder, fluorescent green powder, diffusion powder, anti-precipitation powder, and silicone adhesive according to the preset amount;

[0042] The diffusion powder contains organosilicon resin spherical fine powder, which is a pure white, regular spherical fraction with an average particle size of 2.2 μm.

[0043] The anti-precipitation powder contains silica, natural sodium-based and calcium-based bentonite, and its average particle size is 2.2 μm.

[0044] S2: Take 95 parts silica gel, 20 parts red powder, 3 parts diffusion powder, and 2 parts anti-precipitation powder, mix them, stir and pour them into a molding machine to form a red fluorescent film;

[0045] S3: Take 95 parts silica gel, 20 parts green powder, 3 parts diffusion powder, and 2 parts anti-precipitation powder, mix them, stir and pour them into a molding machine to form a green fluorescent film;

[0046] S4: The low-power blue light chip is fixed into the cup using a die bonder. Then, a green fluorescent film is placed on top of the blue light chip using the die bonder. Next, a red fluorescent film is placed on top of the green fluorescent film using the die bonder. The film is then baked and cured. The gaps inside the cup are filled with transparent silicone to complete the encapsulation. Due to the high concentration of phosphor in the film, the white light illumination effect suitable for high power can be obtained through the principle of three primary colors.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be understood that, for those skilled in the art, other equivalent substitutions may be made to the embodiments, and all such substitutions should be included within the protection scope of the present invention as long as they conform to the feature range defined in the claims.

Claims

1. A method for preparing a white LED phosphor film package, characterized in that: It comprises the following steps: S1: prepare red powder, green powder, diffusion powder, anti-settling powder, and silica gel glue according to preset amounts; S2: mix 95-105 parts of silica gel, 15-20 parts of red powder, 2-3 parts of diffusion powder, and 1-2 parts of anti-settling powder, pour them into a mold press after stirring, and mold them into a red fluorescent film; S3: mix 95-105 parts of silica gel, 15-20 parts of green powder, 2-3 parts of diffusion powder, and 1-2 parts of anti-settling powder, pour them into a mold press after stirring, and mold them into a green fluorescent film; S4: fix a blue light chip in a bowl cup through a die bonder, cover the green fluorescent film on the blue light chip through the die bonder, cover the red fluorescent film on the green fluorescent film through the die bonder, bake and solidify, and fill transparent silica gel in the gap inside the bowl cup to complete packaging.

2. The method for preparing white LED phosphor film encapsulation as described in claim 1, characterized in that: The red powder and the green powder are both fluorescent powder.

3. The method for preparing white LED phosphor film encapsulation as described in claim 1, characterized in that: The diffusion powder contains spherical fine silicone resin powder.

4. The method for preparing white LED phosphor film encapsulation as described in claim 3, characterized in that: The spherical fine silicone resin powder is a pure white regular spherical particle.

5. The method for preparing white LED phosphor film encapsulation as described in claim 3, characterized in that: The average particle size of the spherical fine silicone resin powder is 1.8-2.2 um.

6. The method for preparing white LED phosphor film encapsulation as described in claim 1, characterized in that: The anti-settling powder contains one or more of silica, natural sodium-based, and calcium-based bentonite.

7. The method for preparing white LED phosphor film encapsulation as described in claim 1, characterized in that: The average particle size of the anti-settling powder is 1.8-2.2 um.

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