Protective material for backside dicing of light emitting diode, preparation method and application thereof

Abstract

The application provides a protective material for backside cutting of a light emitting diode, a preparation method and application. The protective material for backside cutting of the light emitting diode comprises the following components in mass ratio: 5-35 parts of a polymer with an amide group, 5-20 parts of branched propylene glycol, 0.5-4 parts of organic polymer particles, 20-40 parts of a film forming aid, and 30-50 parts of ultrapure water. The protective material for backside cutting of the light emitting diode uses the polymer with the amide group and the branched propylene glycol as main film forming substances, and for the first time uses the organic polymer particles as a film layer reinforcing agent. The protective material for backside cutting of the light emitting diode can be well attached to the surface of a sphere to form a film layer, and can be well bonded with a die bonding film. The protective material has excellent water solubility, and can be conveniently removed after laser cutting.

Description

Technical Field

[0001] This invention relates to temporary protective material technology, and more particularly to a protective material for back-side cutting of light-emitting diodes, its preparation method, and its application. Background Technology

[0002] With the rapid development of technology, light-emitting diode (LED) technology has emerged as a dark horse in the field of light sources, demonstrating extremely strong development momentum. In the manufacturing process of LED light-emitting components, laser cutting and separation is a crucial core process that plays a decisive role in the final performance and quality of the product.

[0003] Given the spherical structure (microlenses / encapsulation protrusions) on the front side of LED light-emitting components, when cutting from the front, the laser beam directly acts on the spherical protrusions. Due to the curvature of the sphere, the laser energy cannot be uniformly distributed, and some areas will be subjected to excessively high energy impacts, thus affecting its optical performance and product quality. For example, gallium nitride-based light-emitting components grown on commonly used sapphire substrates typically contain nanopillar arrays or multiple quantum well (MQW) structures. Their front spherical structure is composed of complex epitaxial layers or encapsulation lenses, and each layer of material has different absorption and reflection characteristics for lasers. When the laser energy density exceeds the material's tolerance threshold, the epitaxial layers or encapsulation materials at the spherical surface will experience lattice structure damage or material degradation due to excessive heating, disrupting the originally ordered atomic arrangement. This not only changes the material's optical properties, such as causing non-uniform refractive index, affecting the light propagation path and thus reducing light extraction efficiency, but may also generate tiny cracks or voids on the spherical surface. These microscopic defects will become centers of light scattering and absorption during subsequent use, greatly affecting the product's luminous uniformity and brightness stability, and severely reducing product quality.

[0004] To address the aforementioned issues, the literature "Optimization of UV Laser Scribing Process for LED Sapphire Wafers" (Ashwini Tamhankar, Rajesh Patel. OPTIMIZATION OF UV LASER SCRIBING PROCESS FOR LEDSAPPHIRE WAFERS[C] / / 29th International Congress on Applications of Lasers & Electro-Optics.: Laser Institute of America (LIA), 2010:947-953.) studies that 355nm laser back-side scribing is superior to front-side scribing and is suitable for sapphire substrates < 150μm thick. Patent CN102881801B discloses a back-cut LED packaging structure. In this structure, the back-cut LED packaging is encapsulated and fixed by solid adhesive during the cutting process, effectively improving the problem of substrate and packaging unit breakage caused by traditional front-side cutting. This enhances the production yield of the back-cut LED packaging structure. Therefore, for advanced processes in manufacturing thin, high-performance LED chips, back-side cutting and separation plays a crucial role.

[0005] However, in practice, components adhere to the die-bonding film. Due to the raised spherical structure of the product surface, gaps inevitably appear between the die-bonding film and the product. During laser cutting, debris generated during the cutting process enters through these gaps under various influences, contaminating the spherical part of the product (as shown in Figure 1). This debris scatters or absorbs light, leading to a decrease in the light emission efficiency of the light-emitting components, reduced brightness uniformity, and even localized light blockage, severely affecting the product's optical performance and reliability. Simultaneously, due to the small contact area between the spherical structure and the die-bonding film, it is prone to misalignment and cutting deviation during the cutting process. While conventional laser grooving protective fluids can isolate most debris, they cannot fill the gaps between the spherical surface and the die-bonding film. Debris adhering to the die-bonding film will re-adhere to the device surface during subsequent cleaning and molding processes, still failing to solve the misalignment problem during the cutting process. Summary of the Invention

[0006] The purpose of this invention is to address the problem that existing light-emitting components are easily contaminated by debris and difficult to fix during laser cutting. This invention proposes a protective material for the back-side cutting of light-emitting diodes (LEDs), which can be used as a temporary filling protective layer during laser cutting of the back side of LEDs. This protective material uses a polymer with amide groups and branched propylene glycol as the main film-forming substances, and for the first time, organic polymer particles are used as film-enhancing agents. This allows the protective material to adhere well to the surface of a sphere to form a film layer and to bond well with the die-bonding film (see [link to invention]). Figure 2 This protective material has excellent water solubility and can be completely removed by washing with water after laser cutting.

[0007] It should be noted that, in this invention, unless otherwise specified, the specific meaning of "comprising" in relation to composition and description includes both open-ended meanings such as "comprising," "including," etc., and closed-ended meanings such as "composed of," "consisting of," etc., and similar meanings.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a protective material for back-side cutting of light-emitting diodes (hereinafter referred to as the protective material), comprising the following components in the following mass proportions:

[0009] 5-35 parts of polymers containing amide groups;

[0010] 5-20 parts of branched propylene glycol;

[0011] 0.5-4 parts of organic polymer particles;

[0012] 20-40 parts of film-forming aid;

[0013] 30-50 parts ultrapure water.

[0014] Furthermore, the polymer having amide groups is a polymer having an acetamide structure.

[0015] Furthermore, the polymer having amide groups is preferably one or more of poly(N-vinylpyrrolidone) (PVP), polyacrylamide (PAM), poly(N-vinylacetamide) (PNVA), and poly(acrylic acid-co-N-vinylacetamide) random copolymers.

[0016] Furthermore, the polymer having amide groups is more preferably poly-N-vinylacetamide.

[0017] Furthermore, the polymer having amide groups is most preferably poly-N-vinylacetamide with a molecular weight of 40,000 to 150,000.

[0018] Polymers with amide groups provide hydrophilicity while forming strong hydrogen bonds, resulting in stronger adhesion to oxide surfaces (metal oxide surfaces, glass surfaces, etc.). Preferably, the polymer with amide groups contains an acetamide structure. The acetamide structure differs from the acrylamide structure in that it has a methyl group attached to the carbonyl group. The saturated carbon chain makes the molecular chain more flexible, and the carbonyl group (C=O) and amino group (-NH2) of the amide group can form more dense hydrogen bonds with the bonding resin on the die-bonded film, enhancing adsorption and forming a tight bond with the die-bonded film.

[0019] Further, the polymer having amide groups is 10-35 parts.

[0020] Furthermore, the branched propylene glycol is polyhydroxypropylene glycol. Polyhydroxypropylene glycol exhibits good dispersibility in aqueous systems, while its branched structure imparts a certain degree of hydrophobicity, thus acting as a bridge in hydrophilic-hydrophobic composite systems. This "amphiphilicity" enables it to simultaneously improve the interfacial bonding force between the polymer and organic polymer particles.

[0021] Further, the branched propylene glycol is one or more of 2-hydroxymethyl-2-methyl-1,3-propanediol, 2-ethyl-2-hydroxymethyl-1,3-propanediol, di(trimethylolpropane), and 2,2-dimethyl-1,3-propanediol.

[0022] Furthermore, the branched propylene glycol is preferably bis(trimethylolpropane).

[0023] Furthermore, the branched propylene glycol is 8-15 parts.

[0024] Furthermore, the organic polymer particles are one or more selected from chitosan nanoparticles, polycaprolactone nanoparticles, polystyrene nanoparticles, and polylactic acid (PLA) nanoparticles. These organic polymer particles can be commercially available or prepared using existing methods well-known to those skilled in the art.

[0025] Furthermore, in this invention, the more suitable chitosan nanoparticles are commercially available porous chitosan nanoparticles, purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0026] In this invention, a suitable polycaprolactone nanoparticle is commercially available PCL100;

[0027] In this invention, a suitable polystyrene nanoparticle is commercially available sulfonic acid-based monodisperse polystyrene PS microspheres, purchased from Xianfeng Nano.

[0028] In this invention, suitable polylactic acid (PLA) nanoparticles can be commercially available PLA-PGA-OH and PLA-PEG nanoparticles, purchased from Xi'an Qiyue Biotechnology Co., Ltd.

[0029] Furthermore, the organic polymer particles are preferably polylactic acid (PLA) nanoparticles.

[0030] Furthermore, the organic polymer particles are more preferably PEG-grafted modified polylactic acid nanoparticles.

[0031] Organic polymer particles can form partial physical entanglement or chemical interaction with the matrix, thereby improving film performance while preventing aggregation. This invention introduces polylactic acid (PLA) nanoparticles to enhance the support of the temporary protective layer and prevent device displacement during cutting. The tensile strength of the film is improved by restricting the movement of molecular chains within the film. Simultaneously, the polymer with amide groups and branched propylene glycol, in addition to their original film-forming function, allow the polymer to stably adsorb onto the surface of the organic polymer particles, achieving "anchoring." The polymer molecules adsorbed on the surface of the organic polymer particles extend their hydrophilic segments (containing a large number of amide groups) into the aqueous phase, forming a hydrophilic "shell." This shell improves the compatibility of the organic polymer particles and, through the steric hindrance effect of the polymer chains, prevents the aggregation of adjacent particles.

[0032] Furthermore, the particle size of the organic polymer particles is 100-800 nm.

[0033] Furthermore, the preferred particle size of the organic polymer particles is 100-500 nm.

[0034] Furthermore, the organic polymer particles are present in quantities of 0.5-2 parts.

[0035] Furthermore, the film-forming aid is a low-carbon alcohol ether.

[0036] Furthermore, the film-forming aid is an alcohol ether with 1-4 carbon atoms.

[0037] Furthermore, the film-forming aid is preferably propylene glycol methyl ether.

[0038] Furthermore, the film-forming aid is 20-35 parts.

[0039] Another object of the present invention discloses a method for preparing a protective material for back-side cutting of light-emitting diodes, comprising the following steps:

[0040] Step 1. At 20-25℃, the polymer with amide groups is added to ultrapure water, followed by the addition of branched propylene glycol, and the mixture is stirred evenly to obtain Agent A;

[0041] Step 2. Mix the organic polymer particles with the film-forming aid to obtain Agent B;

[0042] Step 3. Mix agent B with agent A to obtain a protective material for cutting the back of a light-emitting diode.

[0043] Furthermore, the stirring speed for mixing in step 1 is 100-500 rpm.

[0044] Further, in step 2, the organic polymer particles and film-forming aids are mixed and then subjected to ultrasonic treatment before being stirred and mixed.

[0045] Furthermore, the ultrasonic treatment power is 15-50kHz, and the ultrasonic treatment time is 30-60min.

[0046] Furthermore, in step 2, the mixing speed is 1000-5000 rpm and the mixing time is 10-30 min.

[0047] Furthermore, in step 3, the mixing speed is 400-600 rpm and the mixing time is 1-3 hours.

[0048] Another object of the present invention discloses the application of a protective material for back-side cutting of light-emitting diodes in the field of laser cutting of the back side of light-emitting diodes.

[0049] Furthermore, the method for using the protective material for cutting the back of the light-emitting diode as a protective layer for laser cutting the back of the light-emitting diode includes the following steps:

[0050] The protective material for cutting the back of the light-emitting diode is spin-coated or scraped onto the surface of the diode component. After semi-curing, a die-attach film is applied to complete the fixation.

[0051] Furthermore, the semi-curing time is 60-180 seconds.

[0052] Furthermore, after laser cutting the back of the LED, deionized water is used to remove the protective material used for cutting the back of the LED at the bottom of the cutting crease, and then die bonding and film expansion are performed; after molding, deionized water is used again to clean and remove the protective material used for cutting on the diode component.

[0053] The protective material, preparation method, and application for back-side cutting of light-emitting diodes of the present invention have the following advantages compared with the prior art:

[0054] 1) The protective material for back-side cutting of LEDs of the present invention uses a polymer containing amide groups and branched propylene glycol as the main film-forming substances. The polymer containing amide groups provides a large number of hydrogen bonds, resulting in stronger adhesion to the surface of the sphere. The primary hydroxyl groups in the branched propylene glycol are highly polar, giving it good solubility in the system. Simultaneously, its branched structure imparts a certain degree of hydrophobicity, thus acting as a bridge in the hydrophilic-hydrophobic composite system. This synergistic effect allows the protective material for back-side cutting of LEDs to not only adhere well to the surface of the sphere to form a film, but also to effectively bond with the die-bonding film. It also maintains its water solubility, facilitating rapid removal after cutting.

[0055] 2) This invention introduces organic polymer particles as film reinforcement agents into the protective material for back-side cutting of light-emitting diodes, which increases the support of the water-based separator and prevents device displacement during cutting. The amide groups in the polymer can form hydrogen bonds with the polar groups of the organic polymer particles (e.g., stable hydrogen bonds can be formed between -OH of PLA and -C=O of PNVA, or between -COOH of PLA and -NH- of PNVA). This hydrogen bond interaction allows the polymer with amide groups to be stably adsorbed on the surface of the organic polymer particles, achieving an "anchoring" effect. The hydrophilic segments (containing a large number of amide groups) of the polymer adsorbed on the surface of the organic polymer particles extend into the aqueous phase, forming a hydrophilic "shell". This shell, on the one hand, improves the compatibility of the organic polymer particles with water, and on the other hand, prevents adjacent particles from agglomerating due to hydrophobic interactions through the steric hindrance effect of the polymer chains, thereby achieving effective dispersion of hydrophobic organic polymer particles in aqueous liquids.

[0056] In summary, the protective material for back-side cutting of LEDs of the present invention can form a water-soluble protective film during laser cutting to prevent debris and vapor from adhering to the spherical surface of the diode. Based on these significant and superior effects, the processing yield of LED components can be significantly improved, processing efficiency can be greatly increased, and production costs can be significantly reduced. Attached Figure Description

[0057] Figure 1 This is a schematic diagram showing the connection between a traditional light-emitting diode and a die-attach film.

[0058] Figure 2 This is a schematic diagram showing the connection between the light-emitting diode and the die-bonding film of the present invention;

[0059] Figure 3 This is a measurement chart of the film thickness prepared in Example 1;

[0060] Figure 4 This is a measurement image of the film thickness prepared in Comparative Example 5;

[0061] Figure 5 The adhesion test diagram of the film layer prepared in Example 1;

[0062] Figure 6 The adhesion test diagram is for the film prepared in Comparative Example 2. Detailed Implementation

[0063] The present invention will be further described below with reference to embodiments. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0064] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0065] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0066] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0067] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0068] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0069] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be 15-25℃.

[0070] Unless otherwise specified, all reagents or instruments used in this instruction manual are commercially available products.

[0071] Examples 1-7

[0072] Examples 1-7 disclose various protective materials for back-side cutting of light-emitting diodes (hereinafter referred to as protective materials). The raw materials and formulations are shown in Table 1, and the preparation methods are as follows:

[0073] Step 1: Prepare ultrapure water, polymers with amide groups, organic polymer particles, branched propylene glycol, and film-forming aids according to the proportions shown in Table 1.

[0074] Step 2: Inject ultrapure water into the reaction vessel and turn on the stirrer at a speed of 350 rpm;

[0075] Step 3: Keep the temperature at 20℃≤T≤25℃, and slowly add the polymer with amide groups to the ultrapure water in Step 2 at a rate of 0.2 parts / min, while stirring until the material is completely dissolved;

[0076] Step 4: Add branched propylene glycol to the above mixture at a rate of 0.8 parts / min, control the stirring speed at 400 rpm, and the dissolution temperature at 25℃≤T≤35℃. Stir and mix thoroughly until uniform and transparent to obtain Agent A.

[0077] Step 5: Add the organic polymer particles to the film-forming aid and sonicate at 30 kHz for 60 min. Then, disperse by high-speed stirring at 2000 rpm for 15 min to obtain Agent B.

[0078] Step 6: Control the stirring speed at 520 rpm, add agent B to agent A at a rate of 0.1 parts / min and continue stirring for 2 hours to reach the most stable state, thus preparing the protective material for back-side cutting of light-emitting diodes.

[0079] Table 1. Raw materials and proportions of protective material for back-side cutting of LEDs in the embodiments.

[0080]

[0081] Comparative Examples 1-5

[0082] Comparative Examples 1-5 disclose various protective materials for back-side cutting of light-emitting diodes. The raw materials and formulations are shown in Table 2, and the preparation methods are the same as those in Example 1.

[0083] Table 2 Raw materials and proportions of protective materials for back-side cutting of comparative LEDs

[0084]

[0085] The protective materials for back-side cutting of LEDs in Examples 1-7 and Comparative Examples 1-5 were tested respectively. The test methods and results are as follows:

[0086] The method of using the protective material for laser-cutting a protective layer on the back of a light-emitting diode includes the following steps:

[0087] Step 1: Clean the LED components with two-fluid ultrapure water to remove surface dust and particles;

[0088] Step 2: Apply the protective material to the surface of the LED component using spin coating or blade coating. Control the spin speed at 500 rpm and the time at 120 seconds to allow the protective material to partially cure. Then, attach the coated surface to the die-bonding film to fix the LED component on the die-bonding film.

[0089] Step 3: Laser cut the silicon dioxide layer from the back using an energy beam to form a single component; the energy beam includes a laser with a power of 0.5 watts to 10.0 watts.

[0090] Step 4: Use pure water to wash away the protective material at the bottom of the cut kerf, and then perform die bonding and film expansion.

[0091] Step 5: After film expansion, perform molding and clean again with pure water or deionized water.

[0092] Performance 1: Adhesion Test Method:

[0093] The adhesion of the film layer to the substrate was measured using the cross-cut adhesion test. A protective material was applied to a smooth substrate surface to form a dried film layer, which was then measured using the cross-cut adhesion test tool.

[0094] The adhesion level represents the ability of the laser-cut protective material on the back of the LED to adhere to the surface of the component. The smaller the adhesion level, the greater the adhesion and the less likely it is to cause coating defects, thus achieving the protective effect of the protective material on the surface of the component.

[0095] Performance 2: Hardness Test Method:

[0096] Increasing the hardness of the film layer allows it to provide better support between the component and the die-bonded film, preventing cutting deviations caused by weak film layer fixation during the cutting process.

[0097] The hardness of the film was measured using the pencil hardness test. A protective material was coated onto a smooth glass substrate to form a dried film, and the hardness of the surface was measured using a three-in-one pencil hardness tester.

[0098] Performance 3: Test method for film thickness:

[0099] After the protective material is coated, it can form a uniform film on the surface of the component, and after the film dries, it can form a base of a certain thickness for filling and protection. Under a certain coating process, the composition is coated on an opaque substrate, dried to form a film, and the film thickness is measured using a film thickness gauge and the average value is calculated.

[0100] The test results are shown in Table 3.

[0101] Table 3 Test Results

[0102]

[0103] As can be seen from the table above, the protective material of this invention produces a film with high adhesion and a large adjustable range for film thickness, making it suitable for perfect filling of gaps. Furthermore, it maintains the rigidity of the film even when it is thick to avoid the risk of cutting misalignment.

[0104] Comparative Example 1 showed a significant decrease in film hardness due to the absence of added organic polymer particles, and a decrease in film thickness due to the reduction in viscosity and solid content.

[0105] Comparative Example 2 uses inorganic nanoparticles instead of organic polymer particles. Due to the high surface energy of nano-silica particles, they are prone to agglomeration in aqueous environment, making it difficult to form a uniform dispersion system. This results in "voids" or "impurity points" at the interface with the substrate, which disrupts the physical adsorption at the interface, leading to a significant decrease in adhesion and uneven film formation.

[0106] Comparative Example 3 uses 1,2-propanediol as a stabilizer. Due to the presence of only two hydroxyl groups in its structure, it can only form linear or low-crosslinked polymer networks during film formation. The network structure is loose, and the molecular chains are highly mobile, resulting in low film hardness, improved flexibility, and reduced adhesion after film formation. Furthermore, due to the slow drying process, it is difficult to form a thick film.

[0107] Comparative Example 4 uses ethylene glycol as a stabilizer. Due to its smallest molecular weight and low viscosity, its molecular chain fluidity is better than that of branched polyols. It is easy to spread but difficult to support the film layer, resulting in good film flexibility, poor compressive strength and hardness, and reduced adhesion. At the same time, since 1,2-propanediol or ethylene glycol are both linear structures without hydrophobic segments, their bridging effect between polymers and organic polymer particles is weakened, and the stability of nanoparticles is reduced.

[0108] Comparative Example 5 uses polyvinyl alcohol (PVA) as the polymer. Due to the strong hydrogen bonds between the hydroxyl groups within the PVA molecule, it tends to self-aggregate, hindering interfacial interactions with PLA. Its stabilization of PLA nanoparticles relies solely on steric hindrance, while PNVA stabilizes PLA nanoparticles through a dual mechanism of hydrogen bonding and steric hindrance. This reduces the dispersion stability of the particles in the system, resulting in decreased film hardness, reduced film uniformity, and difficulty in increasing film thickness.

[0109] Figure 3 The thickness measurement image of the film prepared in Example 1; from Figure 3 It can be seen that the protective material of the present invention can achieve a film thickness of more than 10 μm by spin coating. The film thickness can be adjusted between 10-40 μm by adjusting the method of use and the process of use, which is fully applicable to surface protection and gap filling with spherical protrusion structure.

[0110] Figure 4 This is a measurement image of the film thickness prepared in Comparative Example 5; Figure 4 To compare the film thickness of the protective liquid under spin coating, it can be seen that the film thickness is thin and cannot meet the requirements for filling the raised spherical surface and gaps.

[0111] Figure 5The adhesion test chart of the film layer prepared in Example 1 shows a grade of 0 in the cross-cut adhesion test. Figure 6 The adhesion test chart for the film layer prepared in Comparative Example 2 is shown, with a cross-cut adhesion test grade of 5. Figure 5 and Figure 6 The comparison shows that the film layer made by the protective material of the present invention has stronger adhesion, reaching level 0, which is significantly better than the adhesion of the comparative example.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A protective material for cutting the back of a light-emitting diode, characterized in that, The components, including their mass proportions, are as follows: 5-35 parts of polymers containing amide groups; 5-20 parts of branched propylene glycol; 0.5-4 parts of organic polymer particles; 20-40 parts of film-forming aid; 30-50 parts ultrapure water.

2. The protective material for back-side cutting of light-emitting diodes according to claim 1, characterized in that, The polymer having amide groups is a polymer having an acetamide structure.

3. The protective material for back-side cutting of a light-emitting diode according to claim 1 or 2, characterized in that, The polymer having amide groups is preferably one or more of poly(N-vinylpyrrolidone), polyacrylamide, poly(N-vinylacetamide), and poly(acrylic acid-co-N-vinylacetamide) random copolymers.

4. The protective material for back-side cutting of light-emitting diodes according to claim 1, characterized in that, The branched propylene glycol is polyhydroxypropylene glycol.

5. The protective material for back-side cutting of a light-emitting diode according to claim 1 or 4, characterized in that, The branched propylene glycol is one or more of 2-hydroxymethyl-2-methyl-1,3-propanediol, 2-ethyl-2-hydroxymethyl-1,3-propanediol, di(trimethylolpropane), and 2,2-dimethyl-1,3-propanediol.

6. The protective material for back-side cutting of a light-emitting diode according to claim 1, characterized in that, The organic polymer particles are one or more of chitosan nanoparticles, polycaprolactone nanoparticles, polystyrene nanoparticles, and polylactic acid nanoparticles.

7. The protective material for back-side cutting of a light-emitting diode according to claim 1, characterized in that, The film-forming aid is an alcohol ether with 1-4 carbon atoms.

8. A method for preparing a protective material for back-side cutting of a light-emitting diode as described in any one of claims 1-7, characterized in that, Includes the following steps: Step 1. At 20-25℃, the polymer with amide groups is added to ultrapure water, followed by the addition of branched propylene glycol, and the mixture is stirred evenly to obtain Agent A; Step 2. Mix the organic polymer particles with the film-forming aid to obtain Agent B; Step 3. Mix agent B with agent A to obtain a protective material for cutting the back of a light-emitting diode.

9. The application of the protective material for back-side cutting of light-emitting diodes as described in any one of claims 1-7 in the field of laser cutting of the back side of light-emitting diodes.

10. The application according to claim 9, characterized in that, The method for using a protective material for laser cutting the back of a light-emitting diode as a protective layer for the back of the light-emitting diode includes the following steps: The protective material for cutting the back of the LED is spin-coated or scraped onto the surface of the LED component. After semi-curing, a die-attach film is applied to complete the fixation.

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