Plasma cutting protection liquid as well as preparation method and application thereof

Abstract

The invention provides a plasma cutting protection liquid and a preparation method and application thereof, and the plasma cutting protection liquid comprises the following components in parts by weight: 15-25 parts of water-soluble polyester resin; 0.2 to 2 parts of a water-soluble UV absorbent; 1-3 parts of a water-soluble builder; 2-10 parts of an auxiliary agent; 45 to 80 parts of a solvent; the water-soluble polyester resin comprises polyfurandicarboxylic acid glycol ester. According to the plasma cutting protection liquid provided by the invention, the polyfurandicarboxylic acid glycol ester and the water-soluble UV absorbent are introduced, so that when a substrate is coated with the plasma cutting protection liquid to form a coating or a thin film, the coating can interact with specific laser, patterning is allowed to be carried out with low energy, and a lower substrate is not influenced; meanwhile, physical etching and chemical etching of plasmas can be resisted in the etching process, and a relatively high plasma etching selection ratio is achieved; after plasma cutting is completed, the coating can be removed through deionized water.

Description

Technical Field

[0001] The invention belongs to the technical field of cutting protection liquid, and relates to a plasma cutting protection liquid and a preparation method and application thereof. Background Art

[0002] With the development of highly integrated and sophisticated semiconductors, the grain density on the wafer has gradually increased and the width of the cutting path has gradually decreased, which has brought greater challenges to the wafer cutting process.

[0003] At present, the laser cutting process technology is relatively mature, and the cost of equipment and raw materials is relatively low. Laser cutting is a physical process of heating and melting. It relies on photon energy to melt silicon to create through holes, and realizes the segmentation of silicon wafers through mechanical stress and heat transfer. Laser cutting does not require a mask, the process is simple, and it has cost advantages in large-scale manufacturing. However, its disadvantage is that the manufactured through holes have high inner wall roughness and thermal damage, which is not conducive to the manufacture of the subsequent diffusion barrier layer of the insulating layer; the mechanical cutting accuracy is not enough, and it is easy to cause defects such as cracks and layer peeling, which is difficult to adapt to more sophisticated integrated circuit component structures, and more advanced cutting technology is required to adapt to more sophisticated needs.

[0004] At present, plasma cutting technology relies on plasma to etch the bottom and sidewalls of silicon in the exposed area, while fluoride forms a passivation layer on the sidewalls and bottom of the through hole to prevent plasma from etching the bottom and sides. After multiple etching cycles, the cycle is superimposed to increase the etching rate of silicon, complete the etching depth in a short time, and achieve damage-free and particle-free cutting, thereby producing intrinsically stronger chips and increasing yields. The manufactured grains are separated from the wafer, and the width of the cutting road is usually micron-level, so the etching process window is much larger. The plasma etching process requires a layer of protective film to be coated on the surface of the wafer, and then the protective film and other film layers applied by the previous process on the surface of the silicon substrate are cut with a laser at the location where cutting is required, so as to form a micron-level mask for plasma cutting. Compared with photolithography, this process of making masks greatly saves process costs and reduces the difficulty of implementation, but it also puts forward strict requirements on the function of the protective film. The performance of plasma cutting protective fluids on the market varies greatly, which seriously restricts the large-scale application of plasma cutting.

[0005] The protective film used for plasma cutting first needs to form a mask with good morphology during the laser cutting process, which requires the protective film to have certain light absorption and thermal conductivity, so as to ensure that the protective film at the cutting path position will not cause the surrounding film layer to be lifted up and affect the protectiveness of the film when it is vaporized during laser cutting. In addition, during the etching process, the protective film needs to be able to resist the physical and chemical etching of the plasma, that is, the protective film needs to have chemical stability to the etchant and must have a certain thickness to withstand the anisotropic ion bombardment of the plasma. Finally, after the plasma cutting is completed, the protective film needs to be washed, so the resin used for the protective film needs to ensure that it will not be excessively cross-linked during the high temperature process of plasma cutting to affect the water washability of the protective film.

[0006] CN118271608A discloses a water-soluble polyimide plasma cutting protection liquid, which has the characteristics of easy film formation, good protection performance, easy water washing and no residue. The cutting protection liquid can form a uniform and dense protective film by simple coating, and provides good high temperature resistance and protection performance in the cutting process. There is no cracking or slag after cutting, forming a good cutting morphology, and improving the chip cutting yield. After use, the protective film can be peeled off by simply washing with deionized water to avoid residual protection liquid. However, the synthesis process of its polyimide is complicated and time-consuming. A highly toxic solvent participates in the reaction during the reaction process. At the same time, the washing residue resin has a greater impact on the environment, and the plasma etching selectivity is less than 200.

[0007] Therefore, there is an urgent need in this field to develop new "green" materials with simpler synthesis steps, no highly toxic solvents involved in the reaction, extremely high selectivity in plasma etching, and easy-to-handle rinse residues. Summary of the invention

[0008] In view of the deficiencies in the prior art, the object of the present invention is to provide a plasma cutting protection liquid and a preparation method and application thereof.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a plasma cutting protection liquid, wherein the plasma cutting protection liquid comprises the following components in parts by weight:

[0011]

[0012] The water-soluble polyester resin includes polyfurandicarboxylic acid glycol ester.

[0013] The plasma cutting protection liquid provided by the present invention introduces polyfurandicarboxylic acid glycol ester and a water-soluble UV absorber, so that when the plasma cutting protection liquid is applied to a substrate to form a coating or a film, the coating can interact with a specific laser, allowing patterning at low energy without affecting the underlying substrate, and can resist the physical etching and chemical etching of plasma during the etching process, and has a higher plasma etching selectivity; after completing the plasma cutting, the coating can be removed by deionized water.

[0014] In the present invention, the amount of the water-soluble polyester resin in the plasma cutting protection liquid can be 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, etc., by weight.

[0015] In the present invention, the amount of the water-soluble UV absorber in the plasma cutting protection liquid can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts, etc., by weight.

[0016] In the present invention, the amount of the water-soluble builder in the plasma cutting protection liquid can be 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts, 2.1 parts, 2.2 parts, 2.3 parts, 2.4 parts, 2.5 parts, 2.6 parts, 2.7 parts, 2.8 parts, 2.9 parts, 3 parts, etc., by weight.

[0017] In the present invention, the amount of the auxiliary agent in the plasma cutting protection liquid can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc., based on weight parts.

[0018] In the present invention, the amount of the solvent in the plasma cutting protection liquid can be 45 parts, 46 parts, 48 ​​parts, 50 parts, 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts, 68 parts, 70 parts, 72 parts, 74 parts, 76 parts, 78 parts, 80 parts, etc., by weight.

[0019] Preferably, the raw materials for preparing the polyfurandicarboxylic acid glycol ester include furandicarboxylic acid and / or furandicarboxylic acid derivatives, a diol compound, and a catalyst.

[0020] Preferably, the molar ratio of the furandicarboxylic acid and / or furandicarboxylic acid derivative to the diol compound is (3-5):(5-7), for example, 3:7, 3.5:6.5, 4:6, 4.5:5.5 or 5:5, etc.

[0021] As a preferred technical solution of the present invention, the molar ratio of the furandicarboxylic acid and / or furandicarboxylic acid derivatives to the diol compound is limited to (3-5):(5-7), so that the plasma cutting protection liquid can achieve the best plasma etching resistance and the most ideal water solubility. On the one hand, if the amount of the furandicarboxylic acid and / or furandicarboxylic acid derivatives is relatively too high, it is easy to cause the obtained polyfurandicarboxylic acid diol ester to be too rigid, and the formed coating is easy to crack under vacuum and lose its protective effect. On the other hand, if the amount of the diol compound is too high, the film layer has poor heat resistance, resulting in a large heat-affected zone when the film layer interacts with the laser, which is not conducive to subsequent etching and cleaning processes.

[0022] Preferably, the furandicarboxylic acid and / or furandicarboxylic acid derivatives include any one of 2,5-furandicarboxylic acid, dimethyl 2,5-furandicarboxylate, 2,4-furandicarboxylic acid, and dimethyl 2,4-furandicarboxylate, or a combination of at least two thereof.

[0023] Preferably, the diol compound includes an aliphatic diol compound and / or an alicyclic diol compound.

[0024] Preferably, the aliphatic diol compound includes any one of 1,3-propylene glycol, 1,4-butylene glycol, 2-methyl-1,3-propylene glycol, 2-amino-2-ethyl-1,3-propylene glycol, 2-amino-2-methyl-1,3-propylene glycol, diethylene glycol, and triethylene glycol, or a combination of at least two thereof.

[0025] Preferably, the alicyclic diol compound includes any one of 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, isosorbide, and tetramethylcyclobutanediol, or a combination of at least two thereof.

[0026] Preferably, based on the total mass of the raw materials for preparing the polyfurandicarboxylic acid diol ester as 100%, the amount of the catalyst is 0.5% to 1%, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc.

[0027] Preferably, the catalyst comprises any one of p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, zinc oxide, and zinc acetate, or a combination of at least two thereof.

[0028] Preferably, the raw materials for preparing the polyfuran dicarboxylic acid diol ester also include sulfonates containing aromatic dicarboxylic acid units. The addition of sulfonates containing aromatic dicarboxylic acid units can improve the water solubility or water dispersibility of the polyfuran dicarboxylic acid diol ester.

[0029] Preferably, based on the total molar number of the furandicarboxylic acid and / or furandicarboxylic acid derivatives and the sulfonate containing aromatic dicarboxylic acid units as 100%, the amount of the sulfonate containing aromatic dicarboxylic acid units is 5%-10%, for example, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0030] Preferably, the sulfonate containing an aromatic dicarboxylic acid unit includes any one of sodium sulfoisophthalic acid, sodium dodecylbenzenesulfonate, sodium 2-formylbenzenesulfonate, and disodium 1,3-benzenedisulfonate, or a combination of at least two thereof.

[0031] Preferably, the polyfurandicarboxylic acid glycol ester is prepared by the following method:

[0032] The furandicarboxylic acid and / or furandicarboxylic acid derivatives, diol compounds, optional sulfonates containing aromatic dicarboxylic acid units, and catalysts are mixed, subjected to esterification and polycondensation reactions, and post-treated to obtain the polyfurandicarboxylic acid diol ester.

[0033] Preferably, the temperature of the esterification reaction is 150-200°C, for example, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C or 200°C, etc.

[0034] Preferably, the esterification reaction time is 2 to 4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours.

[0035] Preferably, the temperature of the polycondensation reaction is 190-230°C, for example, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C, 225°C or 230°C.

[0036] Preferably, the polycondensation reaction time is 2 to 4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours or 4 hours.

[0037] Preferably, the esterification reaction and polycondensation reaction are carried out under the protection of an inert gas.

[0038] Preferably, the inert gas comprises nitrogen.

[0039] Preferably, the post-treatment comprises vacuuming.

[0040] Preferably, the vacuum degree of the vacuum extraction is 10-50 Pa, for example, 10 Pa, 20 Pa, 30 Pa, 40 Pa or 50 Pa.

[0041] Preferably, the vacuuming time is 0.5 to 2.5 h, for example, 0.5 h, 1 h, 1.5 h, 2 h or 2.5 h.

[0042] Preferably, the water-soluble UV absorber includes any one of sodium distyryl biphenyl disulfonate, disodium phenyl dibenzimidazole tetrasulfonate, and terephthalylidene dicamphor sulfonate, or a combination of at least two thereof.

[0043] Preferably, the water-soluble builder includes any one of sodium polystyrene sulfonate, sodium polyanethole sulfonate, sodium xylene sulfonate, or a combination of at least two thereof.

[0044] Preferably, the auxiliary agent comprises a neutralizer and / or a plasticizer.

[0045] Preferably, the auxiliary agent includes 1 to 5 parts (e.g., 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.) of a neutralizer and 1 to 5 parts (e.g., 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.) of a plasticizer.

[0046] Preferably, the neutralizing agent includes any one of dimethylethanolamine, diethanolamine, triethanolamine, or a combination of at least two thereof.

[0047] The present invention does not particularly limit the pH value of the plasma cutting protection liquid, but when it is in the so-called neutral zone of preferably about pH 5 to 8, more preferably about pH 6 to 8, it is easy to operate, has little impact on the wafer processing device, is easy to maintain the device, and causes little damage to the device.

[0048] Preferably, the plasticizer includes any one of propylene carbonate, dibutyl maleate, and dioctyl maleate, or a combination of at least two of them.

[0049] Preferably, the solvent includes any one of water, alcohol solvents, glycol ether solvents, or a combination of at least two of them. That is, the solvent used in the present invention may be pure water, or water and one or more of alcohol solvents, glycol ether solvents, etc. may be mixed together for use. When these substances are mixed, wettability or ductility when the plasma cutting protection liquid is used to protect the wafer surface can be improved, thereby improving coating properties.

[0050] Preferably, the alcohol solvent includes isopropanol and / or glycerol.

[0051] Preferably, the glycol ether solvent includes propylene glycol methyl ether.

[0052] In a second aspect, the present invention provides a method for preparing the plasma cutting protection liquid as described in the first aspect, the preparation method comprising the following steps:

[0053] The plasma cutting protection liquid is obtained by mixing the water-soluble polyester resin, the water-soluble UV absorber, the water-soluble builder, the auxiliary agent and the solvent in the prescribed amount.

[0054] Preferably, the mixing rotation speed is 400-600 rpm, for example, 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, etc.

[0055] Preferably, the mixing time is 2 to 4 hours, for example, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, etc.

[0056] Preferably, the mixing further comprises a filtering step.

[0057] In a third aspect, the present invention provides an application of the plasma cutting protection liquid as described in the first aspect in wafer laser cutting.

[0058] Specifically, taking a 12-inch wafer as an example, the method for using the plasma cutting protection liquid may include the following steps:

[0059] Apply 15-25mL of plasma cutting protection liquid evenly on the wafer surface at a speed of 800-1500rpm; the coating time can be 120-180s. When using larger or smaller wafers, use plasma cutting protection liquid as needed. After spin coating the plasma cutting protection liquid to form a protective film according to the above steps, laser cutting can be performed. After the chip cutting is completed, use deionized water to dissolve and clean the remaining residues and stains together with the plasma cutting protection liquid film.

[0060] The coated substrate is sent to the laser patterning process. Once joined, the tool checks the substrate and looks for alignment marks to set the reference position of the substrate to the system's internal software and programmed process. The laser generates ultraviolet radiation within 340nm to 370nm and preferably within 350nm to 365nm. This emission area is aligned with the absorption area of ​​the UV absorber in the coating. After the mask is produced, which is preferably completed within 1 cycle, the wafer is sent to the plasma chamber, where the same inspection occurs, alignment marks are found, and the system is matched with the substrate. Minimal process descum is performed to further remove the area within the mask of the plasma etcher to ensure high uniformity. Chemical etching continues until complete singulation is completed. The wafer is transferred to the cleaning step, in which the hot water soluble coating is washed away with DIW cleaning. Cleaning occurs in a tool that provides a spin rinse drying sequence. After cleaning, the wafer is ready for single chip removal. The chips are removed by a pick and place tool and placed in a tray or on tape and reel for transport to the final location where they will be mounted in a component and tested.

[0061] The present invention dissolves polyfurandicarboxylic acid glycol ester and a hot water-soluble UV absorber in a solvent to prepare a liquid composition, which is coated on a microelectronic substrate, dried to form a coating or film, and then an exposed area is generated by laser interaction with a given wavelength between 340nm and 370nm in the ultraviolet region, and the substrate is transferred to a plasma chamber, in which the open area generated by the laser is etched until the device chip is completely singulated (separated), and then the coating mask is washed (dissolved) with water. The present invention uses deionized water as a solvent, no toxic solvent is involved in the synthesis reaction, the reaction steps are simple and easy to operate, the plasma etching selectivity is more than 300, and as a "green" material, its washing residue is easily degraded and harmless to the environment.

[0062] Compared with the prior art, the present invention has at least the following beneficial effects:

[0063] The plasma cutting protection liquid provided by the present invention introduces polyfurandicarboxylic acid glycol ester and a water-soluble UV absorber, so that when the plasma cutting protection liquid is applied to a substrate to form a coating or a film, the coating can interact with a specific laser, allowing patterning at low energy without affecting the underlying substrate, and can resist the physical etching and chemical etching of plasma during the etching process, and has a higher plasma etching selectivity; after completing the plasma cutting, the coating can be removed by deionized water. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0065] Preparation Example 1

[0066] In this preparation example, polyfurandicarboxylic acid glycol ester is provided, and the preparation method comprises the following steps:

[0067] According to the formula in Table 1 (the amount of each raw material is in parts by weight), 2,5-furandicarboxylic acid, 1,4-cyclohexanedimethanol, diethylene glycol, sodium sulfoisophthalate and catalyst dodecylbenzenesulfonic acid are weighed, and then poured into a 500 ml four-mouth biscuit, and a stirring and condensing device is installed; stirring is started to mix the raw materials evenly, the temperature is raised to 100° C., and the temperature is kept for 1 hour; the temperature is raised to 140° C., and the temperature is kept for 1 hour, at which time all the reaction raw materials are dissolved, and then N2 is connected; the temperature is raised to 160° C., and the temperature is raised to 180° C. within 3 hours; at 180° C., the temperature is kept for 2 hours; the temperature is raised to 220° C., and the temperature is kept for 2 hours, at which time no by-product methanol is distilled out, and the esterification reaction is basically completed.

[0068] After keeping the temperature at 220°C for 2 hours, N2 was turned off and vacuum was applied. A large amount of by-product ethylene glycol was distilled out, and the vacuum degree was slowly increased to 10 Pa. After vacuuming for 1 hour, the reaction was terminated and the product was poured out to obtain the polyfuran dicarboxylic acid glycol ester (referred to as resin 1).

[0069] Preparation Examples 2 to 7

[0070] Provided is a polyfurandicarboxylic acid diol ester, which is different from Preparation Example 1 only in that the type and / or amount (parts by weight) of the preparation raw materials are different, as shown in Table 1. The contents not shown in Table 1 are deemed to be the same as those in Preparation Example 1; the obtained products are respectively recorded as Resin 2 to Resin 7.

[0071] Table 1

[0072]

[0073] Example 1

[0074] In this embodiment, a plasma cutting protection liquid is provided. The specific components and dosage (parts by weight) of the plasma cutting protection liquid are shown in Table 2.

[0075] The preparation method comprises the following steps:

[0076] The polyfurandicarboxylic acid glycol ester and the solvent are mixed, and then a water-soluble detergent, a water-soluble UV absorber, a plasticizer, and a neutralizer are added to obtain a mixed solution, and the mixed solution is stirred at 500 rpm for 3 hours until the solid in the solution is completely dissolved and clear, thereby obtaining the plasma cutting protection solution.

[0077] Embodiments 2 to 9

[0078] The only difference from Example 1 is that the specific components and amounts are different, as shown in Table 2.

[0079] Table 2

[0080]

[0081] Comparative Example 1

[0082] The difference between this comparative example and Example 1 is that the polyfuran dicarboxylic acid glycol ester is replaced by an equal weight portion of polyvinyl alcohol (brand name ELVANOL TM ).

[0083] Comparative Example 2

[0084] The difference between this comparative example and Example 1 is that the polyfurandicarboxylic acid glycol ester is replaced by an equal weight portion of polyvinyl pyrrolidone (brand name: povidone PVPK30).

[0085] Comparative Example 3

[0086] The only difference between this comparative example and Example 1 is that the polyfurandicarboxylic acid glycol ester is replaced by an equal weight portion of polyimide (brand number PL500L).

[0087] Performance Testing

[0088] (1) Room temperature storage stability test: The plasma cutting protection liquid provided in the above embodiments and comparative examples was stored at room temperature, and the storage conditions of the protection liquid were observed within 1 day, 4 days, 7 days, 12 days, and 18 days to determine whether there was particle precipitation. The test results are shown in Table 3 below.

[0089] Table 3

[0090] Storage time 1d 4d 7d 12d 18d Example 1 No precipitation No precipitation No precipitation No precipitation No precipitation Example 2 No precipitation No precipitation No precipitation No precipitation No precipitation Example 3 No precipitation No precipitation No precipitation No precipitation No precipitation Example 4 No precipitation No precipitation No precipitation No precipitation No precipitation Example 5 No precipitation No precipitation No precipitation No precipitation No precipitation Example 6 No precipitation No precipitation No precipitation No precipitation No precipitation Example 7 No precipitation No precipitation No precipitation Separation Separation Example 8 No precipitation No precipitation No precipitation No precipitation No precipitation Example 9 No precipitation No precipitation No precipitation No precipitation No precipitation Comparative Example 1 No precipitation No precipitation No precipitation No precipitation No precipitation Comparative Example 2 No precipitation No precipitation No precipitation No precipitation No precipitation Comparative Example 3 No precipitation No precipitation No precipitation No precipitation No precipitation

[0091] It can be seen from Table 3 that, except for Example 7, the storage stability of the plasma cutting protection liquid provided by other examples and comparative examples of the present invention at room temperature can exceed 18 days; no sulfonate was added to the polyfuran dicarboxylic acid diol ester used in Example 7 during the synthesis process.

[0092] (2) Heat resistance test: The temperature of 2% thermal weight loss after the plasma cutting protection liquid is formed into a film is tested using a TGA instrument. The test results are shown in Table 4 below.

[0093] Table 4

[0094]

[0095]

[0096] It can be seen from Table 4 that, except for Example 6, the 2% thermal weight loss temperature of the adhesive film prepared by the plasma cutting protection liquid provided by other embodiments of the present invention is all above 250°C, and has excellent heat resistance, while the diol components of the polyfurandicarboxylic acid diol ester used in Example 6 are all fatty alcohols during the synthesis process, and the film surface rigidity is weak and the heat resistance is poor. The 2% thermal weight loss temperature of the adhesive film prepared by the plasma cutting protection liquid provided by Comparative Examples 1 and 2 is all below 160°C, and the thermal stability is poor due to high temperature denaturation, while Comparative Example 3 has excellent thermal stability.

[0097] (3) Cleaning ability: Take 20 mL of the plasma cutting protection liquid provided in the above embodiment and comparative example, and then apply it on a 12-inch wafer at a spin coating parameter of 1000 rpm and 120 s, and then perform laser cutting. After the chip cutting is completed, use deionized water to dissolve and clean the remaining residues and stains together with the plasma cutting protection liquid film, and observe the cleaning effect. The test results are shown in Table 5 below.

[0098] Table 5

[0099]

[0100]

[0101] ○ means it can be cleaned, and ⅹ means it cannot be cleaned.

[0102] It can be seen from Table 5 that the protective films made from the plasma cutting protective liquid provided in the embodiments of the present invention can be cleaned under water drop conditions and have excellent water solubility and cleaning ability, while the protective films made from the plasma cutting protective liquid provided in Comparative Examples 1-2 cannot be cleaned by water flow.

[0103] (4) Vacuum film surface: The film-formed wafer is placed in a vacuum environment and the film surface condition is observed. The test results are shown in Table 6.

[0104] Table 6

[0105] Test subjects Vacuum membrane surface Example 1 intact Example 2 intact Example 3 intact Example 4 intact Example 5 Cracking Example 6 intact Example 7 intact Example 8 Cracking Example 9 intact Comparative Example 1 intact Comparative Example 2 intact Comparative Example 3 intact

[0106] As can be seen from Table 6, Example 5 shows that when synthesizing polyfurandicarboxylic acid glycol ester, if the diol components are all alicyclic diols, the film surface prepared by the plasma cutting protection liquid is too rigid and easy to crack. The film surface prepared by the plasma cutting protection liquid provided by Example 8 is too rigid because no plasticizer is added in Example 8 to adjust, which will cause the film surface to crack under vacuum.

[0107] (5) Absorption coefficient: Spin-coat the plasma cutting protection liquid on a 4-inch glass, use clean glass as the substrate, select a wavelength of 300-800nm ​​for testing, select the transmittance value at 355nm, and then use a step meter to measure the film thickness. Calculate the absorption coefficient based on the absorption coefficient formula.

[0108] Heat affected zone: After the laser cutting process is completed, the wafer is placed under an optical microscope to observe the edge exposed by the laser cutting path and measure the size of the area where burrs exist on the edge.

[0109] The test results are shown in Table 7.

[0110] Table 7

[0111] Test subjects Absorption coefficient Heat affected zone size / μm Example 1 1.60 ＜2.0 Example 1 1.54 ＜2.8 Example 2 1.55 ＜2.5 Example 3 1.50 ＜3.0 Example 4 1.59 ＜2.0 Example 5 1.61 ＜1.8 Example 6 1.53 ＜2.2 Example 7 1.62 ＜1.8 Example 8 1.55 ＜2.2 Example 9 1.58 ＜2.0 Comparative Example 1 0.71 ＜4.5 Comparative Example 2 0.93 ＜5.0 Comparative Example 3 1.13 ＜4.0

[0112] It can be seen from Table 7 that the absorption coefficients of the films made from the plasma cutting protection liquid provided by the embodiments of the present invention are all greater than 1.5, and have extremely strong absorption capacity for 355nm wavelength light sources, while the absorption coefficients of the films made from the plasma cutting protection liquid provided by the comparative examples are all lower than 1.2, and have poor absorption capacity for 355nm wavelength light sources.

[0113] (6) Etching depth: Use an etcher to perform a plasma dry etching test and observe the cross section.

[0114] Selectivity: Use an etcher to perform a plasma dry etching test, measure the film thickness based on a refractive index of 1.3, and calculate the selectivity.

[0115] The test results are shown in Table 8.

[0116] Table 8

[0117] Test subjects Section depth / μm Select ratio Example 1 86 341 Example 2 85 332 Example 3 84 326 Example 4 82 336 Example 5 83 340 Example 6 85 300 Example 7 80 320 Example 8 81 342 Example 9 85 331 Comparative Example 1 78.1 30 Comparative Example 2 77.5 45 Comparative Example 3 80.1 134

[0118] It can be seen from Table 8 that the etching depths of the embodiments of the present invention can all exceed 80 μm, and the etching depths are relatively deep, while the etching depths of the comparative examples are relatively low, but the difference is not significant.

[0119] It can also be seen from Table 8 that the selectivity of the embodiments of the present invention can exceed 300, indicating that the film formed by the protective solution with polyfuran dicarboxylic acid glycol ester as the main body has a higher unit etching ability and a higher etching depth for the same film thickness loss.

[0120] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the plasma cutting protection liquid and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A plasma cutting protection liquid, characterized in that: The plasma cutting protection liquid comprises the following components in parts by weight: The water-soluble polyester resin includes polyfurandicarboxylic acid glycol ester.

2. The plasma cutting protection liquid according to claim 1, characterized in that: The raw materials for preparing the polyfurandicarboxylic acid diol ester include furandicarboxylic acid and / or furandicarboxylic acid derivatives, diol compounds and catalysts.

3. The plasma cutting protection liquid according to claim 2, characterized in that: The molar ratio of the furandicarboxylic acid and / or furandicarboxylic acid derivative to the diol compound is (3-5):(5-7); Preferably, the furandicarboxylic acid and / or furandicarboxylic acid derivatives include any one of 2,5-furandicarboxylic acid, dimethyl 2,5-furandicarboxylate, 2,4-furandicarboxylic acid, and dimethyl 2,4-furandicarboxylate, or a combination of at least two thereof; Preferably, the diol compound comprises an aliphatic diol compound and / or an alicyclic diol compound; Preferably, the aliphatic diol compound includes any one of 1,3-propylene glycol, 1,4-butylene glycol, 2-methyl-1,3-propylene glycol, 2-amino-2-ethyl-1,3-propylene glycol, 2-amino-2-methyl-1,3-propylene glycol, diethylene glycol, and triethylene glycol, or a combination of at least two thereof; Preferably, the alicyclic diol compound includes any one of 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, isosorbide, and tetramethylcyclobutanediol, or a combination of at least two thereof.

4. The plasma cutting protection liquid according to claim 2 or 3, characterized in that: Based on the total mass of the raw materials for preparing the polyfurandicarboxylic acid diol ester as 100%, the amount of the catalyst is 0.5% to 1%; Preferably, the catalyst comprises any one of p-toluenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, zinc oxide, and zinc acetate, or a combination of at least two thereof.

5. The plasma cutting protection liquid according to any one of claims 2 to 4, characterized in that: The raw materials for preparing the polyfurandicarboxylic acid diol ester also include sulfonates containing aromatic dicarboxylic acid units; Preferably, the amount of the sulfonate containing aromatic dicarboxylic acid units is 5%-10%, based on the total molar number of the furandicarboxylic acid and / or furandicarboxylic acid derivatives and the sulfonate containing aromatic dicarboxylic acid units as 100%; Preferably, the sulfonate containing an aromatic dicarboxylic acid unit includes any one of sodium sulfoisophthalic acid, sodium dodecylbenzenesulfonate, sodium 2-formylbenzenesulfonate, and disodium 1,3-benzenedisulfonate, or a combination of at least two thereof.

6. The plasma cutting protection liquid according to any one of claims 2 to 5, characterized in that: The polyfurandicarboxylic acid glycol ester is prepared by the following method: The furandicarboxylic acid and / or furandicarboxylic acid derivative, a diol compound, an optional sulfonate containing an aromatic dicarboxylic acid unit, and a catalyst are mixed, and subjected to esterification reaction and polycondensation reaction, and post-processing to obtain the polyfurandicarboxylic acid diol ester; Preferably, the temperature of the esterification reaction is 150-200°C; Preferably, the esterification reaction time is 2 to 4 hours; Preferably, the temperature of the polycondensation reaction is 190 to 230°C; Preferably, the polycondensation reaction time is 2 to 4 hours; Preferably, the esterification reaction and polycondensation reaction are carried out under the protection of an inert gas; Preferably, the post-processing comprises vacuuming; Preferably, the vacuum degree of the vacuum pumping is 10-50 Pa; Preferably, the vacuuming time is 0.5 to 2.5 hours.

7. The plasma cutting protection liquid according to any one of claims 1 to 6, characterized in that: The water-soluble UV absorber includes any one of sodium distyryl biphenyl disulfonate, disodium phenyl dibenzimidazole tetrasulfonate, and terephthalylidene dicamphor sulfonate, or a combination of at least two thereof; Preferably, the water-soluble builder comprises any one of sodium polystyrene sulfonate, sodium polyanethole sulfonate, sodium xylene sulfonate, or a combination of at least two thereof; Preferably, the auxiliary agent includes a neutralizer and / or a plasticizer; Preferably, the auxiliary agent includes 1 to 5 parts of a neutralizer and 1 to 5 parts of a plasticizer; Preferably, the neutralizing agent comprises any one of dimethylethanolamine, diethanolamine, triethanolamine, or a combination of at least two thereof; Preferably, the plasticizer includes any one of propylene carbonate, dibutyl maleate, and dioctyl maleate, or a combination of at least two of them.

8. The plasma cutting protection liquid according to any one of claims 1 to 7, characterized in that: The solvent includes any one of water, alcohol solvents, and glycol ether solvents, or a combination of at least two thereof; Preferably, the alcohol solvent comprises isopropanol and / or glycerol; Preferably, the glycol ether solvent includes propylene glycol methyl ether.

9. A method for preparing a plasma cutting protection liquid as claimed in any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: Mixing the water-soluble polyester resin, the water-soluble UV absorber, the water-soluble builder, the auxiliary agent and the solvent in the formula amount to obtain the plasma cutting protection liquid; Preferably, the mixing speed is 400-600 rpm; Preferably, the mixing time is 2 to 4 hours.

10. Use of the plasma cutting protection liquid according to any one of claims 1 to 8 in wafer laser cutting.

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