Method for preventing fingerprints on surface of LED product

Abstract

The invention provides a method for preventing fingerprints on the surface of an LED (light-emitting diode) product. The method comprises the following steps: preprocessing the surface of the packaged LED product; coating the surface of the pretreated LED product with a coating solution, and curing to obtain an anti-fingerprint coating; the anti-fingerprint coating contains polysiloxane; and the hydrophobic angle of the anti-fingerprint coating is 100-120 degrees, and the oleophobic angle of the anti-fingerprint coating is 75-85 degrees. According to the method, the hydrophobic and oleophobic performance of the surface of the LED lamp bead can be effectively improved, the appearance change of a product is not caused, and the brightness of the LED lamp bead is not influenced.

Description

Technical Field

[0001] The invention belongs to the field of LED manufacturing and relates to a method for preventing fingerprints on the surface of an LED product. Background Art

[0002] The structure of an LED lamp bead generally consists of a bracket, chip, encapsulant, and wires. The encapsulant is primarily composed of epoxy resin and filler. The top surface of the LED lamp bead is composed of encapsulant and PPA, creating a layer of plastic material. After the LED lamp bead is mounted on the client, the LED lamp beads are densely attached to the module board. During the repeated assembly and disassembly of the module board, the operator's hands will constantly come into contact with the surface of the LED lamp beads, leaving sweat and oil stains on the entire screen. This can cause fingerprint contamination on the entire display, adversely affecting the appearance and difficult to remove.

[0003] Current LED packaging and SMD screen factories still rely primarily on manual assembly and unloading, without established control measures requiring the use of gloves. This is also constrained by the increasing complexity of LED display screen usage scenarios. Workers' hands directly contact the surface of LED modules, leaving dirt and causing fingerprints on the module surfaces. High-end LED products require a higher matte finish for LED lamp beads. Once contaminated by fingerprints, the product surface can become shiny or darkened. This phenomenon is further amplified after assembly into large screens. Currently, there are no suitable protective measures in the LED packaging industry to address the fingerprint problem. Summary of the Invention

[0004] In order to solve the above technical problems, the present application provides a method for preventing fingerprints on the surface of LED products. This method can effectively improve the hydrophobic and oleophobic properties of the surface of LED lamp beads without causing changes in the appearance of the product and affecting the brightness of the LED lamp beads.

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

[0006] The present invention provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0007] Pre-treat the surface of packaged LED products;

[0008] Applying a coating solution on the surface of the pre-treated LED product and curing it to obtain an anti-fingerprint coating;

[0009] The anti-fingerprint coating contains polysiloxane;

[0010] The hydrophobic angle of the anti-fingerprint coating is 100-120°, and the oleophobic angle is 75-85°.

[0011] As a preferred technical effect of the present invention, the polysiloxane includes any one of polydimethylsiloxane, polydiethylsiloxane or polymethylphenylsiloxane, or a combination of at least two thereof.

[0012] As a preferred technical effect of the present invention, the coating solution contains a fluorine solvent.

[0013] As a preferred technical effect of the present invention, the fluorine solvent includes any one of perfluorobutyl methyl ether, perfluorobutyl ethyl ether or perfluoropolyether, or a combination of at least two thereof.

[0014] As a preferred technical effect of the present invention, the coating solution contains 20 to 80% of polysiloxane and 20 to 80% of fluorine solvent by mass.

[0015] As a preferred technical effect of the present invention, the thickness of the anti-fingerprint coating is 0.1 to 1 μm.

[0016] As a preferred technical effect of the present invention, the pretreatment is plasma cleaning.

[0017] As a preferred technical effect of the present invention, the gas source for plasma cleaning is nitrogen and / or hydrogen.

[0018] As a preferred technical effect of the present invention, the power of plasma cleaning is 200-500W.

[0019] As a preferred technical effect of the present invention, the plasma cleaning time is 60 to 300 seconds.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] (1) The present application provides a method for preventing fingerprints on the surface of LED products. The method can effectively improve the hydrophobic and oleophobic properties of the surface of LED lamp beads. It is not easy for oil stains to remain after the hands of staff come into contact with the surface of LED lamp beads, and even if there are oil stains, they can be easily wiped off.

[0022] (2) The present application provides a method for preventing fingerprints on the surface of LED products. The method does not change the appearance of the product and does not affect the brightness of the LED lamp beads. DETAILED DESCRIPTION

[0023] The technical solution of this application is further explained below through specific implementation methods.

[0024] A specific embodiment of the present invention provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0025] Pre-treat the surface of packaged LED products;

[0026] Applying a coating solution on the surface of the pre-treated LED product and curing it to obtain an anti-fingerprint coating;

[0027] The anti-fingerprint coating contains polysiloxane;

[0028] The hydrophobic angle of the anti-fingerprint coating is 100-120°, and the oleophobic angle is 75-85°.

[0029] Among them, the hydrophobic angle can be 100°, 102°, 105°, 108°, 110°, 112°, 115°, 118° or 120°, etc., and the oleophobic angle can be 75°, 76°, 77°, 78°, 79°, 80°, 81°, 82°, 83°, 84° or 85°, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] In this invention, by pre-treating the surface of the encapsulated LED product, the bonding strength between the anti-fingerprint coating and the LED product surface is improved, effectively preventing the problem of the anti-fingerprint coating falling off during subsequent processing of the LED product. The addition of polysiloxane to the anti-fingerprint coating can effectively improve the hydrophobic and oleophobic properties of the anti-fingerprint coating. The anti-fingerprint coating has a hydrophobic angle of 100-120° and an oleophobic angle of 75-85°. Its excellent hydrophobic and oleophobic properties make it difficult for workers' hands to retain oil residue after contact with the surface of the LED lamp beads, and even if oil residue does occur, it can be easily wiped away.

[0031] In a specific embodiment of the present invention, the polysiloxane includes any one of polydimethylsiloxane, polydiethylsiloxane or polymethylphenylsiloxane, or a combination of at least two thereof, preferably polydimethylsiloxane.

[0032] In one embodiment of the present invention, the number average molecular weight of the polydimethylsiloxane may be 5,000 to 100,000 g / mol.

[0033] In one embodiment of the present invention, the coating solution contains a fluorinated solvent.

[0034] In the present invention, the fluorinated solvent not only improves the dispersion performance of components such as polysiloxane and improves the coating performance of the coating solution, but also the synergistic effect of the small amount of fluorinated solvent remaining after curing and the polysiloxane can further improve the hydrophobic and oleophobic properties of the anti-fingerprint coating.

[0035] In one embodiment of the present invention, the fluorinated solvent includes any one of perfluorobutyl methyl ether, perfluorobutyl ethyl ether, or perfluoropolyether, or a combination of at least two thereof.

[0036] In one embodiment of the present invention, the coating solution contains 20-80% polysiloxane and 20-80% fluorinated solvent. The mass fraction of the polysiloxane can be 20%, 30%, 40%, 50%, 60%, 70%, or 80%, and the mass fraction of the fluorinated solvent can be 20%, 30%, 40%, 50%, 60%, 70%, or 80%, etc., but the values ​​are not limited to the values ​​listed above. Other values ​​within this range are also applicable.

[0037] In one embodiment of the present invention, the anti-fingerprint coating may further contain additives such as antioxidants, leveling agents, antistatic agents, and adhesion promoters to enhance the coating performance and stability of the anti-fingerprint coating. The specific type, substance, presence, and amount of additives can be adjusted based on the coating effect of the coating solution and the application conditions after film formation, and are not further limited herein.

[0038] In a specific embodiment of the present invention, the thickness of the anti-fingerprint coating is 0.1 to 1 μm, such as 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm or 1 μm, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0039] In one embodiment of the present invention, the pretreatment is plasma cleaning.

[0040] In the present invention, by plasma cleaning the surface of the packaged LED product, surface dirt can be effectively removed, and the surface energy of the product surface can be activated, so that the coating can be more firmly attached to the product packaging surface, thereby improving the bonding strength of the anti-fingerprint coating.

[0041] In one embodiment of the present invention, the plasma cleaning gas source is nitrogen and / or hydrogen, preferably a mixture of hydrogen and nitrogen. The volume ratio of hydrogen to nitrogen can be adjusted according to the effect of plasma cleaning, for example, 2:1, 1:1, or 1:2.

[0042] In a specific embodiment of the present invention, the power of plasma cleaning is 200-500W, such as 200W, 250W, 300W, 350W, 400W, 450W or 500W, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0043] In a specific embodiment of the present invention, the plasma cleaning time is 60 to 300 seconds, such as 60 seconds, 120 seconds, 180 seconds, 240 seconds or 300 seconds, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0044] In a specific embodiment of the present invention, the coating solution can be applied by brushing, dipping or spraying, etc., which can be adjusted according to processing requirements and coating effects and is not further limited herein.

[0045] In one embodiment of the present invention, the coating can be cured by heat curing, such as at a temperature of 100-150°C for 1-5 hours. Alternatively, the coating can be cured by standing at room temperature for 12-48 hours. The curing method can be selected based on product processing requirements. Heat curing is more efficient, but for heat-sensitive products, standing at room temperature may be preferable.

[0046] In one embodiment of the present invention, for example, the LED product packaging process may include die bonding, wire bonding, and adhesive dispensing on an empty LED support. The present invention does not require specific surface properties of the encapsulated LED product; any LED product obtained through a common LED packaging process is suitable for the present LED product surface fingerprint prevention method.

[0047] In a specific embodiment of the present invention, after the surface of the LED product is subjected to anti-fingerprint treatment, the treated LED lamp beads can be stripped, split, and bagged, and then manufactured into LED module boards through an SMD placement machine.

[0048] In one embodiment of the present invention, the aforementioned method for preventing fingerprints on the surface of LED products is applicable to any conventional LED product, such as the top2424-S1 and top1415-S3 LED products. The top2424-S1 refers to an LED lamp bead with a product size of 2.4cm*2.4cm and an internal cup size of 1.5*1.5cm; the top1415-S3 refers to an LED lamp bead with a product size of 1.5*1.5cm and an internal cup size of 1.2*1.2cm.

[0049] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0050] Example 1

[0051] This embodiment provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0052] The surface of the packaged LED product (top2424-S1) was plasma cleaned using a mixture of nitrogen and hydrogen (volume ratio 1:1) at 300W power for 180s.

[0053] Apply a coating solution (containing polydimethylsiloxane, number average molecular weight 5000-100000 g / mol, content 50 wt%, perfluorobutyl methyl ether, mass fraction 50 wt%) to the surface of the LED product, and then dry and cure at 120°C for 2 h to obtain a 0.2 μm anti-fingerprint film.

[0054] The processed LED lamp beads are stripped, split, and bagged, and then made into LED module boards through an SMD placement machine.

[0055] Example 2

[0056] This embodiment provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0057] The surface of the packaged LED product (top2424-S1) was plasma cleaned using a mixture of nitrogen and hydrogen (volume ratio 1:1) at 300W power for 180s.

[0058] A coating solution (containing polydimethylsiloxane, number average molecular weight 5000-100000 g / mol, content 70 wt%, perfluorobutyl methyl ether, mass fraction 30 wt%) was brush-coated on the surface of the LED product and cured and dried at 110°C for 2.5 h to obtain a 0.2 μm anti-fingerprint film;

[0059] The processed LED lamp beads are stripped, split, and bagged, and then made into LED module boards through an SMD placement machine.

[0060] Example 3

[0061] This embodiment provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0062] The surface of the packaged LED product (top2424-S1) was plasma cleaned using a mixture of nitrogen and hydrogen (volume ratio 1:1) at 300W power for 180s.

[0063] A coating solution (containing polydimethylsiloxane, number average molecular weight 5000-100000 g / mol, content 40 wt%, perfluorobutyl methyl ether, mass fraction 60 wt%) was brush-coated on the surface of the LED product and cured and dried at 130°C for 1.5 h to obtain a 0.2 μm anti-fingerprint film;

[0064] The processed LED lamp beads are stripped, split, and bagged, and then made into LED module boards through an SMD placement machine.

[0065] Example 4

[0066] This embodiment provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0067] The surface of the packaged LED product (top2424-S1) was plasma cleaned using a mixture of nitrogen and hydrogen (volume ratio 1:1) at 300W power for 180s.

[0068] A coating solution (containing polydimethylsiloxane, number average molecular weight 5000-100000 g / mol, content 50 wt%, perfluorobutyl ether, mass fraction 50 wt%) was brush-coated on the surface of the LED product and cured and dried at 120°C for 2 h to obtain a 0.2 μm anti-fingerprint film;

[0069] The processed LED lamp beads are stripped, split, and bagged, and then made into LED module boards through an SMD placement machine.

[0070] Example 5

[0071] This embodiment provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0072] The surface of the packaged LED product (top2424-S1) was plasma cleaned using a mixture of nitrogen and hydrogen (volume ratio 1:1) at 300W power for 180s.

[0073] Apply a coating solution (containing polydimethylsiloxane, number average molecular weight 5000-100000 g / mol, content 80 wt%, perfluoropolyether, mass fraction 20 wt%) to the surface of the LED product, and then cure and dry at 120°C for 2 h to obtain a 0.2 μm anti-fingerprint film.

[0074] The processed LED lamp beads are stripped, split, and bagged, and then made into LED module boards through an SMD placement machine.

[0075] Example 6

[0076] This embodiment provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0077] The surface of the packaged LED product (top2424-S1) was plasma cleaned using a mixture of nitrogen and hydrogen (volume ratio 1:1) at a power of 200W for 300s.

[0078] Apply a coating solution (containing polydimethylsiloxane, number average molecular weight 5000-100000 g / mol, content 50 wt%, perfluorobutyl methyl ether, mass fraction 50 wt%) to the surface of the LED product, and then dry and cure at 120°C for 2 h to obtain a 0.2 μm anti-fingerprint film.

[0079] The processed LED lamp beads are stripped, split, and bagged, and then made into LED module boards through an SMD placement machine.

[0080] Example 7

[0081] This embodiment provides a method for preventing fingerprints on the surface of an LED product, the method comprising:

[0082] The surface of the packaged LED product (top2424-S1) was plasma cleaned using a mixture of nitrogen and hydrogen (volume ratio 1:1) at 500W for 60s.

[0083] Apply a coating solution (containing polydimethylsiloxane, number average molecular weight 5000-100000 g / mol, content 50 wt%, perfluorobutyl methyl ether, mass fraction 50 wt%) to the surface of the LED product, and then dry and cure at 120°C for 2 h to obtain a 0.2 μm anti-fingerprint film.

[0084] The processed LED lamp beads are stripped, split, and bagged, and then made into LED module boards through the SMD placement machine.

[0085] Example 8

[0086] In this embodiment, except that the LED product top2424-S1 is replaced by top1415-S3, the rest of the price adjustment is the same as that in embodiment 1.

[0087] Comparative Example 1

[0088] In this comparative example, an LED product (top2424-S1) without pretreatment and anti-fingerprint coating was directly stripped, split, and bagged, and then manufactured into an LED module board using an SMD placement machine.

[0089] Comparative Example 2

[0090] In this comparative example, except that the pre-treated LED product (top2424-S1) is directly stripped, split, and bagged, and then manufactured into an LED module board by an SMD placement machine, the other conditions are the same as those in Example 1.

[0091] Comparative Example 3

[0092] In this comparative example, except that the LED product (top2424-S1) was directly coated with the anti-fingerprint film without pretreatment, other conditions were the same as those in Example 1.

[0093] Comparative Example 4

[0094] In this comparative example, except that perfluorobutyl methyl ether was replaced by tert-butyl methyl ether, the other conditions were the same as those in Example 1.

[0095] Comparative Example 5

[0096] In this comparative example, the conditions are the same as those in Example 1, except that the pretreatment is replaced by wiping the surface of the LED product with acetone and ethanol in sequence.

[0097] The LED module boards provided in Examples 1-8 and Comparative Examples 1-5 were evaluated according to the following evaluation method. The evaluation results are shown in Table 1.

[0098] <1> Measurement of brightness

[0099] The brightness of the LED lamp beads was tested using a German IS standard test machine with a test current of R\G\B=5mA\3mA\2mA, and the brightness values ​​of the LED lamp beads before and after treatment were recorded.

[0100] <2> Determination of hydrophobicity

[0101] The manufactured LED module board is sprayed with a faucet for testing. If water droplets adhere to the surface of the product, it is hydrophilic. If all water droplets fall from the surface of the product, it is hydrophobic.

[0102] <3> Fingerprint appearance test

[0103] Dip your hands in lubricating grease and touch the surface of the finished LED module board. Then observe the fingerprints on the surface from the side. Wipe the surface oil with alcohol and observe the product texture and matte appearance changes under a microscope. If there are no fingerprints or changes in the surface appearance, it is OK. Otherwise, it is NG.

[0104] <4> PCT shedding test

[0105] Place the LED module board in a PCT test chamber. The experimental conditions are 121°C, 1.5 atmospheres, and 100% humidity. The test time is 72 hours. Observe whether there is any material falling off the surface of the product.

[0106] Table 1

[0107] sample R-IV G-IV B-IV Hydrophobicity test Fingerprint appearance test PCT shedding test Example 1 59.2 153.6 34.7 hydrophobic OK No shedding Example 2 61.1 155.3 34.6 hydrophobic OK No shedding Example 3 58.9 154.1 35.8 hydrophobic OK No shedding Example 4 60.1 152.2 35.5 hydrophobic OK No shedding Example 5 60.2 151.8 34.3 hydrophobic OK No shedding Example 6 60.3 152.4 34.6 hydrophobic OK No shedding Example 7 59.9 155.6 34.7 hydrophobic OK No shedding Example 8 59.7 152.9 34.8 hydrophobic OK No shedding Comparative Example 1 60.4 152.4 34.5 hydrophilic NG Comparative Example 2 60.2 154.6 35.1 hydrophilic NG Comparative Example 3 59.3 152.3 34.8 hydrophobic OK Falling off Comparative Example 4 59.5 152.1 35.2 hydrophilic NG No shedding Comparative Example 5 59.4 151.6 34.5 hydrophobic OK Falling off

[0108] The table shows that neither pre-treatment nor post-treatment of the LED product surface affects its brightness or matte finish. After both pre- and post-treatment, the coating material adheres firmly to the product surface, forming a hydrophobic and oleophobic protective layer that prevents and resolves fingerprint issues.

[0109] The applicant declares that the present invention uses the above-described embodiments to illustrate the detailed process equipment and process flow of the present invention. However, the present invention is not limited to the above-described detailed process equipment and process flow, and does not necessarily rely on the above-described detailed process equipment and process flow in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for the raw materials of the present invention's products, additions of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for preventing fingerprints on the surface of LED products, characterized in that: The method comprises: Pre-treat the surface of packaged LED products; Applying a coating solution on the surface of the pretreated LED product, and curing the solution to obtain an anti-fingerprint coating; The anti-fingerprint coating contains polysiloxane; The anti-fingerprint coating has a hydrophobic angle of 100 to 120 degrees and an oleophobic angle of 75 to 85 degrees.

2. The method for preventing fingerprints on the surface of LED products according to claim 1, characterized in that: The polysiloxane includes any one of polydimethylsiloxane, polydiethylsiloxane or polymethylphenylsiloxane, or a combination of at least two thereof.

3. The method for preventing fingerprints on the surface of LED products according to claim 1, characterized in that: The coating solution contains a fluorine solvent.

4. The method for preventing fingerprints on the surface of LED products according to claim 3, characterized in that: The fluorine solvent includes any one of perfluorobutyl methyl ether, perfluorobutyl ethyl ether or perfluoropolyether, or a combination of at least two thereof.

5. The method for preventing fingerprints on the surface of LED products according to claim 3, characterized in that: Calculated by mass fraction, the coating solution contains 20-80% of polysiloxane and 20-80% of fluorine solvent.

6. The method for preventing fingerprints on the surface of LED products according to claim 1, characterized in that: The thickness of the anti-fingerprint coating is 0.1-1 μm.

7. The method for preventing fingerprints on the surface of LED products according to claim 1, characterized in that: The pretreatment is plasma cleaning.

8. The method for preventing fingerprints on the surface of LED products according to claim 7, characterized in that: The gas source for the plasma cleaning is nitrogen and / or hydrogen.

9. The method for preventing fingerprints on the surface of LED products according to claim 7, characterized in that: The power of the plasma cleaning is 200-500W.

10. The method for preventing fingerprints on the surface of LED products according to claim 7, characterized in that: The plasma cleaning time is 60 to 300 seconds.