Plasma cutting protection material, its preparation method and application

Abstract

The application discloses a plasma cutting protection material, a preparation method and application thereof, and comprises the following components in parts by mass: resin 18-40 parts, toughening agent 0.1-2 parts, hydrolysis aid 0.7-4 parts, and solvent 50-100 parts. In the plasma cutting protection material, the resin is partially hydrolyzed by the hydrolysis aid, so that the hydrophilicity of the resin is enhanced, the miscibility with the solvent is improved, and a complete protection film can be formed on a wafer surface to resist etching of plasma; after the cutting process is completed, the formed protection film has extremely strong water solubility and can be easily removed, so that the cleaning process is simple.

Description

Technical Field

[0001] This application belongs to the field of logic chip cutting, specifically relating to a plasma cutting protective material, its preparation method and application. Background Technology

[0002] Traditional wafer dicing involves using a dicing blade to cut a wafer into individual chips or dies. However, as logic chips become smaller and more precise, the requirements for dicing also increase. Therefore, logic chip dicing has evolved from dicing to laser dicing. Both blade dicing and laser dicing are physical cutting methods, using mechanical stress and heat transfer to divide the logic chip. These two methods cannot meet the increasingly stringent precision requirements. Plasma dicing, on the other hand, uses chemical etching to divide the wafer, causing no mechanical damage, heat-affected zones, or other physical impacts on the chip, effectively improving the yield of existing dicing methods. Plasma dicing requires creating a protective film on the logic chip surface, and the laser dicing process opens the surface film layer to allow the plasma to contact the substrate. Therefore, a protective solution is needed to coat the logic chip surface with a protective film during plasma dicing.

[0003] Plasma dicing machines use methods such as ionized gas discharge to generate high-temperature plasma on materials, using this high energy to cut the material. During this process, the plasma generates a large amount of heat, so the final protective film layer of the plasma dicing solution must have excellent temperature resistance. During plasma dicing, the plasma gas etches not only the exposed dicing path but also the protective film layer coated with the dicing solution. If the film layer is not thick enough, the protective film layer is etched away before the plasma gas completes the dicing process. After the film layer is removed, the plasma gas continues to etch the chip, causing irreversible damage. Therefore, the plasma dicing protective solution needs a sufficiently thick film layer. To achieve a high film thickness, the resin content in the protective solution needs to be increased, which also increases the viscosity. Excessive viscosity makes it impossible to extract through the pipeline and easily causes pipeline blockage, making it unsuitable for use in chip dicing machines. Currently, wafer protection materials typically cannot meet the three conditions of high temperature resistance, high film thickness, and low viscosity. Summary of the Invention

[0004] Purpose of application: This application provides a plasma cutting protective material, its preparation method and application, aiming to provide a cutting protective material with a viscosity of less than 200 mPa·s, a film thickness of more than 3 μm and excellent temperature resistance, so as to improve cutting efficiency and the yield of semiconductor products.

[0005] Technical solution: This application discloses a plasma cutting protective material, which, by weight, comprises the following components:

[0006]

[0007] In some embodiments, the resin is selected from homopolymers of at least one of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and lauryl acrylate; or, the resin is selected from copolymers of any two of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and lauryl acrylate.

[0008] In some embodiments, the resin is selected from any one of polymethyl methacrylate, polyethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, and polylauryl acrylate, and the number average molecular weight of the resin is 1000-20000.

[0009] In some embodiments, the toughening agent is a polymer crosslinked with polydimethylsiloxane and polyethylene glycol.

[0010] In some embodiments, the toughening agent is selected from at least one of a polymer crosslinked with polydimethylsiloxane and PEG-10, and a polymer crosslinked with polydimethylsiloxane and PEG-15.

[0011] In some embodiments, the hydrolysis aid is an inorganic acid.

[0012] In some embodiments, the inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, and the pH of the plasma cutting protective material is 3-5.

[0013] In some embodiments, the solvent is selected from any one or any combination of water, alcohol, and ether.

[0014] In some embodiments, this application also provides a method for preparing a plasma cutting protective material, comprising the following steps:

[0015] Weigh out the respective mass fractions of resin, toughening agent, hydrolysis aid, and solvent, mix them, and stir at 200-500 rpm for 1-8 hours at 30-90℃ to obtain the plasma cutting protective material.

[0016] In some embodiments, this application also provides the application of a plasma cutting protective material in wafer cutting.

[0017] In some embodiments, the application specifically includes: dropping the dicing protection material onto the wafer and spin-coating it; wherein the wafer size is 4-12 inches, and the amount of dicing protection material dropped is any one of 10 mL / 4 inch, 15 mL / 6 inch, 25 mL / 8 inch, and 35 mL / 12 inch.

[0018] Beneficial effects: Compared with the prior art, the plasma cutting protective material of this application partially hydrolyzes the resin through a hydrolysis aid, which enhances the hydrophilicity of the resin, improves its miscibility with the solvent, and can form a complete protective film on the wafer surface to resist plasma etching; after the cutting process is completed, the formed protective film has extremely strong water solubility and can be easily removed, making the cleaning process simple.

[0019] It is understood that, compared with the prior art, the preparation method of the plasma cutting protective material and the application of the plasma cutting protective material provided in this application have all the technical features and beneficial effects of the aforementioned plasma cutting protective material, and will not be repeated here. Attached Figure Description

[0020] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0021] Figure 1 This is the infrared spectrum of polymethyl methacrylate in Example 1 of this application;

[0022] Figure 2 This is the infrared spectrum of polymethyl methacrylate after hydrolysis in Example 1 of this application. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0024] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for mutual communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements or the interaction between two elements. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically limited. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more features.

[0025] The following disclosure provides many different implementations or examples for carrying out different structures of this application. To simplify the disclosure of this application, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit this application.

[0026] The applicant discovered that traditional wafer dicing involves using a dicing blade to ultimately cut a wafer into individual chips or dies. However, as logic chips become smaller and more precise, the requirements for dicing also increase. Therefore, existing wafer dicing has evolved from dicing to laser dicing. Both blade dicing and laser dicing are physical cutting methods, using mechanical stress and heat transfer to divide silicon wafers. The precision of these two methods cannot meet the increasingly stringent precision requirements. Plasma dicing, on the other hand, uses chemical etching to divide wafers, causing no mechanical damage, heat-affected zones, or other physical impacts on the chips, effectively improving the yield of existing dicing methods. However, plasma dicing requires the formation of a protective film on the wafer surface, and the laser dicing process needs to open the surface film layer to allow the plasma to contact the substrate. Therefore, a protective material is needed to coat the wafer surface to create this protective film. However, traditional dicing protective materials have low thermal stability and poor film-forming properties, making them unable to withstand the high-temperature environment and etching requirements of plasma dicing, thus failing to provide adequate protection for the chips.

[0027] Based on this, embodiments of this application provide a plasma cutting protective material, comprising the following components by weight: 18-40 parts resin, 0.1-2 parts toughening agent, 0.7-4 parts hydrolysis aid, and 50-100 parts solvent.

[0028] Furthermore, in some embodiments, a plasma cutting protective material is provided, comprising, by weight, the following components: 20-35 parts resin, 0.2-1.5 parts toughening agent, 1-3 parts hydrolysis aid, and 60-90 parts solvent.

[0029] Furthermore, in some embodiments, a plasma cutting protective material is provided, comprising, by weight, the following components: 22-30 parts resin, 0.5-1.2 parts toughening agent, 1.5-2 parts hydrolysis aid, and 70-85 parts solvent.

[0030] In some embodiments, the resin is selected as a homopolymer of at least one of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and lauryl acrylate.

[0031] In some embodiments, the resin is selected from copolymers of any two of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and lauryl acrylate.

[0032] Understandably, the resin used is an acrylic homopolymer resin, which has high crystallinity, a high melting point, and a high glass transition temperature. This gives it good stability in high-temperature environments, allowing it to withstand the high temperatures encountered in plasma cutting. Simultaneously, the homopolymer resin can be partially hydrolyzed with the help of hydrolysis aids, enhancing its hydrophilicity and making it miscible with water. This improves the film-forming properties of the plasma cutting protective material, and the resulting protective film can also resist plasma etching, enhancing the protection of the wafer.

[0033] In some embodiments, the resin is selected from any one of polymethyl methacrylate, polyethyl acrylate, polyethyl methacrylate, polybutyl acrylate, and polylauryl acrylate, and the number average molecular weight of the resin is 1,000-20,000. Further, the number average molecular weight is preferably 2,000-10,000, and most preferably 3,000-8,000.

[0034] It should be noted that controlling the molecular weight between 1000 and 20000 can enhance the water solubility of the resin and is beneficial for increasing the film thickness in the later coating process. Furthermore, resins within this molecular weight range have excellent film-forming properties, enabling the formation of a complete protective film on the wafer surface. High-thickness protective materials can be produced even with low viscosity, and the water solubility is extremely strong. After the dicing process, the protective film can be easily removed by water, simplifying the cleaning process.

[0035] In some embodiments, the toughening agent is a polymer crosslinked with polydimethylsiloxane and polyethylene glycol. For example, the toughening agent is selected from one or more of polydimethylsiloxane / PEG-10 crosslinked polymers and polydimethylsiloxane / PEG-15 crosslinked polymers. Polydimethylsiloxane / PEG-10 crosslinked polymer is preferred. In PEG-10, the 10 represents the number of ethylene glycol units in the polyethylene glycol molecule (10), and the same applies to PEG-15.

[0036] It should be noted that toughening agents and solvents, such as propylene glycol methyl ether, have high compatibility, which can increase the flexibility of the film layer, allowing the film layer to better conform to the complex structure of the wafer surface, reduce its brittleness, and prevent the protective film layer from breaking.

[0037] In some embodiments, the hydrolysis aid is an inorganic acid. When the hydrolysis aid is added to the system, it reacts with water molecules, creating an acidic environment in the water. This acidic environment can disrupt the aggregate or micelle structure of the resin polymer, making it more susceptible to hydrolysis by water molecules. Specifically, the inorganic acid can hydrolyze the ester bonds in the resin molecules into carboxylic acids.

[0038] In some embodiments, the inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, preferably hydrochloric acid or sulfuric acid, and most preferably hydrochloric acid, and the pH of the plasma cutting protective material is 3-5. An acidic environment helps inhibit bacterial growth and extends the service life of the cutting protective material and the product.

[0039] In some embodiments, the solvent is selected from any one or any combination of water, alcohol, and ether. The water is deionized water; the alcohol may be, for example, any one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, and isobutanol; the ether may be, for example, any one or more of diethyl ether, methyl ethyl ether, di-n-butyl ether, propylene glycol methyl ether, and ethylene glycol propyl ether; preferably, deionized water, isopropanol, propylene glycol methyl ether, or any combination of these substances; most preferably, a combination of deionized water and isopropanol, or a combination of deionized water and propylene glycol methyl ether. The amount of water used is 30-90 parts by weight, preferably 40-80 parts by weight, and most preferably 50-75 parts by weight; the amount of isopropanol used is 5-50 parts by weight, preferably 5-40 parts by weight, and most preferably 5-20 parts by weight.

[0040] It should be noted that when the solvent is a combination of deionized water and propylene glycol methyl ether, the propylene glycol methyl ether, with a flash point of 31.1℃, readily evaporates, dries rapidly, and forms a film. The propylene glycol methyl ether molecule contains both alcohol and ether functional groups, thus providing unique polar and non-polar solubility. This surfactant-like structure allows the alcohol and ether to couple different phases, increasing the resin's solubility. Deionized water provides cooling and endothermic effects, and is both environmentally friendly and cost-effective. Furthermore, both solvents are relatively mild and will not damage the chip during use.

[0041] In some embodiments, this embodiment provides a method for preparing a plasma cutting protective material, including the following steps:

[0042] Weigh out the resin, toughening agent, hydrolysis aid, and solvent by their respective mass fractions and mix them. Stir at 200-500 rpm for 1-8 hours at 30-90℃ to obtain the plasma cutting protective material.

[0043] In some embodiments, the stirring temperature is preferably 50-80°C, and most preferably 70°C.

[0044] In some embodiments, the stirring time is preferably 2-5 hours, and most preferably 3 hours.

[0045] In some embodiments, the stirring speed may be any one of 200 rpm, 300 rpm, 400 rpm, 500 rpm, or a range between any two of these values.

[0046] In some embodiments, the application of plasma cutting protective materials in wafer dicing is also provided. These materials can adapt to various wafer structures, forming a protective film on the wafer surface to ensure the wafer is not scratched by debris during dicing, thereby improving the yield of semiconductor products and the efficiency of dicing. The plasma cutting protective material of this embodiment has very promising application prospects and large-scale industrial application potential in the field of cutting protection.

[0047] The specific method for using wafer dicing protective materials is as follows:

[0048] First, clean the wafers of different sizes that are to be coated;

[0049] Set the spin coating program, drop the cutting protection material onto the wafer, and spin coat at 1000 rpm for 2 minutes;

[0050] After spin coating, proceed to the next cutting process.

[0051] In some embodiments, in the step of dropping and spin-coating a dicing protective material onto a wafer, the wafer size is 4-12 inches, and the amount of dicing protective material dropped is any one of 10 mL / 4 inch, 15 mL / 6 inch, 25 mL / 8 inch, or 35 mL / 12 inch.

[0052] In some embodiments, taking polymethyl methacrylate resin as an example, the specific steps of its preparation method are as follows:

[0053] Under nitrogen protection, 80-150 parts, preferably 90-120 parts, and most preferably 100-110 parts of methyl methacrylate; the initiator can be azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, ammonium persulfate, etc., preferably azobisisobutyronitrile or benzoyl peroxide, and most preferably azobisisobutyronitrile; the amount is 0.2-1.5 parts, preferably 0.5-1 part, and most preferably 0.8 parts of the initiator azobisisobutyronitrile (AIBN); 100-200 parts, preferably 120-180 parts, and most preferably 150 parts of propylene glycol methyl ether are added to the reactor;

[0054] The reaction vessel is heated to 50-110℃, preferably 75-85℃, and most preferably 80℃; the reactants are heated and stirred, and the reaction time is 2-48h, preferably 6-8h, and most preferably 7h; polymethyl methacrylate resin is obtained.

[0055] Example 1

[0056] A plasma cutting protective material is provided, comprising, by weight: 30 parts resin, 1 part toughening agent, 1.5 parts hydrolysis aid, and 85 parts solvent; wherein the resin is polymethyl methacrylate with a number average molecular weight of 5000, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is hydrochloric acid, and the solvent is a combination of deionized water and propylene glycol methyl ether, wherein deionized water comprises 70 parts and propylene glycol methyl ether comprises 15 parts.

[0057] The preparation process is as follows: weigh out the resin, toughening agent, hydrolysis aid and solvent in their respective mass parts and mix them. Stir at 300 rpm for 3 hours at 70℃ to obtain the wafer dicing protective material; the pH of the plasma dicing protective material is 4.5.

[0058] See Figure 1 The infrared spectrum of polymethyl methacrylate before hydrolysis is shown below. Figure 1 The 3004 cm⁻¹ spectrum can be seen. -1 2965cm -1 2926cm -1 The stretching vibration of -CH3 indicates the presence of a methyl group; 1421 cm⁻¹ -1 and 1362cm -1 The bending vibration of -CH3 further confirmed the presence of the methyl group; at 1723 cm⁻¹ -1 This is due to the carbonyl C=O stretching vibration, and the presence of methyl formate units on the surface. See also Figure 2 The infrared spectrum of the hydrolyzed polymethyl methacrylate prepared in this invention is obtained from... Figure 2 It can be seen from this that at 1723cm -1 The peak area of ​​the carbonyl C=O stretching vibration is significantly smaller than that of the carbonyl group. Figure 1 The peak area at the carbonyl group indicates that the resin has undergone hydrolysis.

[0059] Example 2

[0060] A plasma cutting protective material is provided, comprising, by weight: 25 parts resin, 0.1 parts toughening agent, 0.7 parts hydrolysis aid, and 50 parts solvent; wherein the resin is a copolymer of polymethacrylic acid and polyethyl acrylate with a number average molecular weight of 2000, the toughening agent is a polymer crosslinked with polydimethylsiloxane and PEG-15, the hydrolysis aid is sulfuric acid, and the solvent is ethanol.

[0061] The preparation process is as follows: weigh out the resin, toughening agent, hydrolysis aid and solvent in their respective mass parts and mix them. Stir at 200 rpm for 8 hours at 30℃ to obtain the wafer dicing protection material; the pH of the plasma dicing protection material is 5.0.

[0062] Example 3

[0063] A plasma cutting protective material is provided, comprising, by weight: 40 parts resin, 2 parts toughening agent, 4 parts hydrolysis aid, and 100 parts solvent; wherein the resin is polyethyl methacrylate with a number average molecular weight of 2000, the toughening agent is a cross-linked polymer of polydimethylsiloxane / PEG-10 and a cross-linked polymer of polydimethylsiloxane and PEG-15, the hydrolysis aid is phosphoric acid, and the solvent is propylene glycol methyl ether.

[0064] The preparation process is as follows: weigh out the resin, toughening agent, hydrolysis aid and solvent in their respective mass parts and mix them. Stir at 400 rpm for 1 hour at 90℃ to obtain the wafer dicing protection material; the number average molecular weight of the plasma dicing protection material is 10000 and the pH is 3.0.

[0065] Example 4

[0066] A plasma cutting protective material is provided, comprising, by weight: 20 parts resin, 0.2 parts toughening agent, 1 part hydrolysis aid, and 60 parts solvent; wherein the resin is polybutyl acrylate with a number average molecular weight of 20,000, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is nitric acid, and the solvent is ethyl acetate.

[0067] The preparation process is as follows: weigh out the resin, toughening agent, hydrolysis aid and solvent in their respective mass parts and mix them. Stir at 500 rpm for 5 hours at 50℃ to obtain the wafer dicing protective material; the pH of the plasma dicing protective material is 4.3.

[0068] Example 5

[0069] A plasma cutting protective material is provided, comprising, by weight: 22 parts resin, 0.5 parts toughening agent, 2 parts hydrolysis aid and 90 parts solvent; wherein the resin is polylauryl acrylate with a number average molecular weight of 2000, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is sulfuric acid, and the solvent is isopropanol.

[0070] The preparation process is as follows: weigh out the resin, toughening agent, hydrolysis aid and solvent in their respective mass parts and mix them. Stir at 300 rpm for 2 hours at 80℃ to obtain the wafer dicing protective material; the pH of the plasma dicing protective material is 3.5.

[0071] Example 6

[0072] A plasma cutting protective material is provided, comprising, by weight: 35 parts resin, 1.2 parts toughening agent, 2 parts hydrolysis aid, and 85 parts solvent; wherein the resin is polymethyl methacrylate with a number average molecular weight of 8000, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is hydrochloric acid, and the solvent is a combination of deionized water and isopropanol, wherein deionized water comprises 70 parts and isopropanol comprises 15 parts.

[0073] The preparation process is as follows: weigh out the resin, toughening agent, hydrolysis aid and solvent in their respective mass parts and mix them. Stir at 300 rpm for 3 hours at 70℃ to obtain the wafer dicing protective material; the pH of the plasma dicing protective material is 3.6.

[0074] Example 7

[0075] A plasma cutting protective material is provided, comprising, by weight: 18 parts resin, 1.5 parts toughening agent, 1.5 parts hydrolysis aid and 70 parts solvent; wherein the resin is polymethyl methacrylate with a number average molecular weight of 1000, the toughening agent is a polymer crosslinked with polydimethylsiloxane and PEG-15, the hydrolysis aid is sulfuric acid, and the solvent is deionized water.

[0076] The preparation process is as follows: weigh out the resin, toughening agent, hydrolysis aid and solvent in their respective mass parts and mix them. Stir at 300 rpm for 3 hours at 70℃ to obtain the wafer dicing protective material; the pH of the plasma dicing protective material is 3.6.

[0077] Comparative Example 1

[0078] A plasma cutting protective material is provided, comprising, by weight: 30 parts resin, 1 part toughening agent, 1.5 parts hydrolysis aid, and 85 parts solvent; wherein the resin is polymethyl methacrylate with a number average molecular weight of 5000, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is citric acid, and the solvent is a combination of deionized water and propylene glycol methyl ether, comprising 70 parts deionized water and 15 parts propylene glycol methyl ether.

[0079] The preparation process is the same as in Example 1.

[0080] Comparative Example 2

[0081] A plasma cutting protective material is provided, comprising, by weight: 30 parts resin, 1 part toughening agent, 1.5 parts hydrolysis aid, and 85 parts solvent; wherein the resin is polyvinylpyrrolidone with a number average molecular weight of 5000, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is hydrochloric acid, and the solvent is a combination of deionized water and propylene glycol methyl ether, comprising 70 parts deionized water and 15 parts propylene glycol methyl ether.

[0082] The preparation process is the same as in Example 1.

[0083] Comparative Example 3

[0084] A plasma cutting protective material is provided, comprising, by weight: 10 parts resin, 1 part toughening agent, 1.5 parts hydrolysis aid, and 85 parts solvent; wherein the resin is polyvinylpyrrolidone with a number average molecular weight of 5000, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is hydrochloric acid, and the solvent is a combination of deionized water and propylene glycol methyl ether, comprising 70 parts deionized water and 15 parts propylene glycol methyl ether.

[0085] The preparation process is the same as in Example 1.

[0086] Comparative Example 4

[0087] A plasma cutting protective material is provided, comprising, by weight: 30 parts resin, 1 part toughening agent, 1.5 parts hydrolysis aid, and 85 parts solvent; wherein the resin is polymethyl methacrylate with a number average molecular weight of 500, the toughening agent is polydimethylsiloxane / PEG-10 crosspolymer, the hydrolysis aid is hydrochloric acid, and the solvent is a combination of deionized water and propylene glycol methyl ether, comprising 70 parts deionized water and 15 parts propylene glycol methyl ether.

[0088] The preparation process is the same as in Example 1.

[0089] Viscosity Measurement

[0090] Viscosities of Examples 1-7 and Comparative Examples 1-4 were measured, and the test results are shown in Table 1. An NDJ-5S rotational viscometer was used for measurement. For viscosities of 20-50, the rotational speed was set to 100 rpm; for viscosities of 50-100, the rotational speed was set to 50 rpm; and for viscosities of 100-200, the rotational speed was set to 10 rpm.

[0091] The plasma cutting protective materials prepared in Examples 1-7 and Comparative Examples 1-4 were each dropped into 25 mL onto a bare silicon wafer. Then, a spin coater was used to coat the wafer at a speed of 1000 rpm for 120 s to ensure uniform coating. The coating was observed to ensure it dried and formed a film, and the film thickness was measured using an AlphaStep D120 step film thickness gauge. Specific data are shown in Table 1.

[0092] Table 1

[0093]

[0094]

[0095] As shown in Table 1, the viscosities of all embodiments in this application are less than 200 mPa·s, meeting the viscosity requirements. However, in Comparative Example 2, because the viscosity of the vinylpyrrolidone monomer is greater than that of the methyl methacrylate monomer, the vinylpyrrolidone polymer is larger than the methyl methacrylate polymer. Therefore, the viscosity of Comparative Example 2 is greater than 200 mPa·s, which is too high to be extracted through the pipeline and would easily cause pipeline blockage, making it unsuitable for use in chip cutting machines. In Comparative Example 1, citric acid is used as a hydrolysis aid, which still has a certain hydrolysis effect; therefore, the viscosity is similar to that of Example 1.

[0096] As shown in Table 1, the film thickness of the embodiments of this application is greater than 3 micrometers, preferably 4-6 micrometers, and more preferably 5 micrometers, which meets the requirements for film thickness. The film thickness is mainly affected by the resin content. The higher the resin content, the greater the film thickness. In Comparative Example 3, the film thickness is less than 3 micrometers due to the low resin content. After the film is completely etched, the plasma gas will continue to etch the wafer surface, resulting in wafer waste.

[0097] The plasma cutting protective materials prepared in Examples 1-7 and Comparative Examples 1-4 were spin-coated onto wafers, and plasma cutting was performed. The yield of the prepared products after high-temperature baking and cleaning was tested. Specific data are shown in Table 2.

[0098] Methods for testing cleaning effectiveness:

[0099] The plasma cutting protective material of the present invention is spin-coated onto the wafer, baked on a heating plate at 300°C for 30 minutes, and then cleaned with pure water using an ASC-3000 model cleaning machine. The area of ​​the wafer that is completely cleaned is then recorded and divided by the wafer area to obtain the wafer cleaning yield.

[0100] Table 2

[0101] Cleaning yield (%) Example 1 100 Example 2 100 Example 3 100 Example 4 100 Example 5 100 Example 6 100 Example 7 100 Comparative Example 1 96.31 Comparative Example 2 98.91 Comparative Example 3 95.15 Comparative Example 4 95.39

[0102] As shown in Table 2, the cleaning yield of the embodiments of this application is greater than that of the comparative examples. In Comparative Example 1, the hydrolysis aid citric acid is less effective than hydrochloric acid in hydrolyzing the carbon-hydrogen bonds and ester bonds in the resin molecules into carboxylic acids and alcohols, resulting in poorer water solubility and a lower cleaning yield. In Comparative Example 2, the polyvinylpyrrolidone ester has insufficient heat resistance, causing the resin to carbonize and deteriorate after heating, resulting in poorer water solubility and a lower cleaning yield. In Comparative Example 3, the insufficient resin content and low film thickness lead to poor overall film heat resistance and a lower cleaning yield. In Comparative Example 4, the resin has a small molecular weight and insufficient heat resistance, causing the resin to carbonize and deteriorate after heating, resulting in poorer water solubility and a lower cleaning yield.

[0103] The above provides a detailed description of a plasma cutting protective material, its preparation method, and its application provided in the embodiments of this application. Specific examples have been used in this application to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core ideas of this application. 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 of the technical features. 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 this application.

Claims

1. A plasma cutting protective material, characterized in that, By weight, the cut protection material comprises the following components: The number-average molecular weight of the resin is 1000-20000; The hydrolysis aid is an inorganic acid; the inorganic acid hydrolyzes the ester bonds in the resin into carboxylic acids; The resin is selected from homopolymers of at least one of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and lauryl acrylate; or, the resin is selected from copolymers of any two of methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, and lauryl acrylate.

2. The plasma cutting protective material according to claim 1, characterized in that, The resin is selected from any one of polymethyl methacrylate, polyethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, and polylauryl acrylate.

3. The plasma cutting protective material according to claim 1, characterized in that, The toughening agent is a polymer crosslinked with polydimethylsiloxane and polyethylene glycol.

4. The plasma cutting protective material according to claim 1, characterized in that, The inorganic acid is selected from at least one of hydrochloric acid, sulfuric acid, phosphoric acid, and nitric acid, and the pH of the plasma cutting protective material is 3-5.

5. The plasma cutting protective material according to claim 1, characterized in that, The solvent is selected from any one or any combination of water, alcohol, and ether.

6. A method for preparing a plasma cutting protective material according to any one of claims 1-5, characterized in that, Includes the following steps: Weigh out the respective mass fractions of resin, toughening agent, hydrolysis aid, and solvent, mix them, and stir at 200-500 rpm for 1-8 h at 30-90℃ to obtain the plasma cutting protective material.

7. The application of any one of the plasma cutting protective materials according to claims 1-5 in wafer cutting.

8. The application according to claim 7, characterized in that, Specifically, it includes: The dicing protection material is dropped onto the wafer and spin-coated; wherein the wafer size is 4-12 inches, and the amount of dicing protection material added is any one of 10 mL / 4 inch, 15 mL / 6 inch, 25 mL / 8 inch, or 35 mL / 12 inch.

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