A cutting protection liquid for high-end CIS chips, its preparation method and use

Abstract

The present application discloses a cutting protection liquid for high-order CIS chips, its preparation method and use, and belongs to the field of cutter wheel cutting chip technology. In parts by mass, the cutting protection liquid includes the following components: 30-130 parts of a protective agent, 0.1-5 parts of an adhesion promoter and 0.01-1 parts of a defoaming agent. The protective agent used in this application contains both hydrophilic groups and hydrophobic groups, showing the effects of a surfactant and a leveling agent. The hydrophobic group can extend toward the surface away from the chip, so that the film layer formed by the protective liquid has hydrophobicity, which can avoid the damage of the film layer to the cutting water during the cutter wheel cutting process; the formed film layer has the technical effects of long water resistance, high adhesion and few residual particles, which can significantly improve the finished product rate and good product rate of high-order CIS chips.

Description

Technical Field

[0001] The present application belongs to the technical field of chip cutting with a cutter wheel, and specifically relates to a cutting protection liquid for high-end CIS chips, and its preparation method and use. Background Art

[0002] Currently, during the cutting process of high-end CIS (Computer Image Sensor) chips using a cutting wheel, water is continuously sprayed during the cutting process. If the protective film formed by the protective liquid has a hydrophilic surface, it is easily damaged by the water sprayed during cutting. This results in poor adhesion of the protective liquid to the chip surface, which can further lead to film shedding during the cutting process. Cutting debris directly adheres to the chip surface, causing chip contamination. Summary of the Invention

[0003] Purpose of application: This application provides a cutting protection liquid for high-end CIS chips, its preparation method and use. The film layer formed by the protection liquid has a hydrophobic effect, which can prevent the cutting water from damaging the coating and improve the adhesion of the cutting protection liquid on the chip surface.

[0004] Technical solution: The present application provides a cutting protection liquid for high-end CIS chips, characterized in that it comprises the following components, calculated by mass: 30-130 parts of a protective agent, 0.1-5 parts of an adhesion promoter, and 0.01-1 parts of a defoaming agent; the structure of the protective agent is shown in the following formula (1):

[0005]

[0006] Wherein, n represents the degree of polymerization; R1 is selected from any one of ethyl, isopropyl and butyl; R2, R3 and R4 are independently selected from one or more of F, Cl, Br and H.

[0007] In some embodiments, the protective agent is prepared from a water-soluble resin and an improver; wherein the structure of the water-soluble resin is shown in the following formula (2), and the structure of the improver is shown in the following formula (3);

[0008]

[0009] In some embodiments, the water-soluble resin is selected from at least one of poly(vinyl methyl ether-alt-maleic acid monoethyl ester), poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester), and poly(vinyl methyl ether-alt-maleic acid monobutyl ester);

[0010] The improver is selected from at least one of difluoroethanol, trifluoroethanol, trichloroethanol, tribromoethanol, 2-chloro-2,2-difluoroethanol, and 2-fluoro-2-bromoethanol.

[0011] In some embodiments, the water-soluble resin has a number average molecular weight of 10,000 to 500,000.

[0012] In some embodiments, the adhesion promoter is selected from at least one of silane coupling agent KH580, trimethoxysilane, phenyltrimethoxysilane, silane coupling agent KH-550, and vinyltriethoxysilane.

[0013] In some embodiments, the defoaming agent is selected from at least one of propylene glycol fatty acid esters, higher alcohol fatty acid esters, polyglycerol fatty acid esters, and tributyl phosphate.

[0014] In some embodiments, the present application further provides a method for preparing a cutting protection liquid for a high-end CIS chip, comprising the following steps:

[0015] Take 30-130 parts of protective agent, 0.1-5 parts of adhesion promoter and 0.01-1 part of defoaming agent, heat to 90-105°C while stirring, and stir at constant temperature for 1.5-2.5 hours; then continue to heat to 135-145°C and stir at this temperature for 0.5-1 hour; finally cool to room temperature to obtain a uniform and transparent cutting protection liquid.

[0016] In some embodiments, the protective agent is prepared by a curing reaction of a water-soluble resin and an improver; wherein the mass ratio of the water-soluble resin to the improver is 10-30:20-100.

[0017] In some embodiments, the curing reaction temperature is 50-100° C., and the curing reaction time is 2-6 minutes.

[0018] In some embodiments, the present application also provides the use of the cutting protection liquid in cutting protection of high-end CIS chips.

[0019] Compared with the prior art, the beneficial effects of the present application are: the cutting protective liquid for high-end CIS chips provided by the present application contains both hydrophilic groups and hydrophobic groups in the protective agent, which exhibits the effects of a surfactant and a leveling agent. The hydrophobic groups can extend toward the surface away from the chip, so that the film layer formed by the protective liquid is hydrophobic, which can avoid the damage of the film layer by the cutting water during the cutting process of the cutter wheel; the formed film layer has the technical effects of long water resistance, high adhesion and few residual particles, which can significantly improve the finished product rate and good rate of high-end CIS chips.

[0020] The present application discloses a method for preparing a cutting protection liquid for high-end CIS chips. The method obtains a protective agent by curing reaction of a water-soluble resin with a specific structure and an improver, which can give the cutting protection liquid excellent film-forming and solubility properties. Under the joint action of an adhesion promoter and a defoaming agent, the formed film layer has the advantages of preventing particles from contaminating the chip surface, excellent protective adhesion, good protection of the cutting path, and easy cleaning and removal. In particular, it can prevent cutting water from damaging the film layer during the wheel cutting process, and is therefore particularly suitable for cutting protection of high-precision and high-requirement precision wafers. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and other beneficial effects of the present application apparent.

[0022] Figure 1 This is a 164x magnified microscope photograph of a high-end CIS chip cut using the cutting protection solution provided in Example 1 of the present application;

[0023] Figure 2 This is a 164x magnified microscope photograph of a high-end CIS chip cut using the cutting protection solution provided in Comparative Example 2 of this application;

[0024] Figure 3 This is a microscope photograph of the cutting path magnified 200 times after cutting a high-end CIS chip using the cutting protection liquid provided in Example 1 of the present application;

[0025] Figure 4 This is a microscope photo of the cutting path magnified 200 times after cutting a high-end CIS chip using the cutting protection liquid provided in Comparative Example 2 of this application;

[0026] Figure 5 This is an infrared spectrum of the protective agent in the cutting protection liquid provided in Example 1 of the present application. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present application and the accompanying drawings to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0028] In the description of the present application, it should be noted that the specific embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application. In the present application, unless otherwise specified, the directional words used, such as "upper" and "lower", specifically refer to the directions of the drawings in the accompanying drawings. In addition, in the description of the present application, the term "including" means "including but not limited to". The various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be understood as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated in this article, it is meant to include any quoted number (fractional or integer) within the indicated range.

[0029] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application.

[0030] This embodiment provides a cutting protection liquid for high-end CIS chips, which comprises the following components, in parts by mass: 30-130 parts of a protective agent, 0.1-5 parts of an adhesion promoter, and 0.01-1 parts of a defoaming agent; the structure of the protective agent is shown in the following formula (1):

[0031]

[0032] Wherein, n represents the degree of polymerization; R1 is selected from any one of ethyl, isopropyl and butyl; R2, R3 and R4 are independently selected from one or more of F, Cl, Br and H.

[0033] In some embodiments, n ranges from 50-2500.

[0034] It can be understood that in the cutting protection liquid of the present application, since the protective agent has both hydrophilic groups, such as ether bonds, ester groups, etc., and hydrophobic groups, such as F, Cl, Br and alkyl groups, the cutting protection liquid exhibits the effects of surfactants and leveling agents, ensuring the coating effect. During the film formation process, the hydrophilic groups can generate forces with the water on the chip surface to form a film layer, increase the contact area between the cutting liquid and the chip surface, and further improve its adhesion; the hydrophobic groups have a large polarity and selectively protrude toward the surface away from the chip, making the surface of the film layer a hydrophobic layer. During the cutting process of the blade wheel, the cutting water will not damage the film layer, the film layer will not fall off, and the cutting debris cannot adhere to the chip surface, thereby greatly improving the product yield.

[0035] In some embodiments, the protective agent is prepared from a water-soluble resin and an improver; wherein the structure of the water-soluble resin is shown in the following formula (2), and the structure of the improver is shown in the following formula (3);

[0036]

[0037] It is understandable that the carboxyl group in the water-soluble resin reacts with the hydroxyl group in the improver to undergo a dehydration condensation reaction, thereby realizing the preparation of the protective agent. The water-soluble resin adopts the above structure because it can provide a hydrophilic group carboxyl group, which helps to improve the adhesion between the protective liquid and the wafer, while also ensuring the excellent coating and film-forming uniformity. The improver adopts the above structure, R2, R3 and R4 can be the same or different. Since it has the same or different hydrophobic groups in its structure, on the one hand, the amphiphilicity of the protective agent can be realized, and the adhesion performance of the protective liquid can be improved. On the other hand, its cleaning performance can also be improved to ensure the cleaning effect after cutting.

[0038] In some embodiments, the water-soluble resin is selected from at least one of poly(vinyl methyl ether-alt-maleic acid monoethyl ester), poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester), and poly(vinyl methyl ether-alt-maleic acid monobutyl ester).

[0039] Therefore, when R1 in formula (2) is an ethyl group, the corresponding water-soluble resin used for preparation is poly(vinyl methyl ether-alt-maleic acid monoethyl ester); when R1 in formula (2) is an isopropyl group, the corresponding water-soluble resin used for preparation is poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester); when R1 in formula (2) is a butyl group, the corresponding water-soluble resin used for preparation is poly(vinyl methyl ether-alt-maleic acid monobutyl ester).

[0040] Among them, the CAS number of poly(vinyl methyl ether-alt-maleic acid monoethyl ester) is 28087-06-3; the CAS number of poly(vinyl methyl ether-alt-maleic acid monobutyl ester) is 25119-68-0; and the CAS number of poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester) is 31307-95-6. It is understood that the water-soluble resin can be obtained through commercial means. Taking poly(vinyl methyl ether-alt-maleic acid monoethyl ester) as an example, it is a polymer of ethyl maleate and vinyl methyl ether. It is highly water-soluble, can be easily dissolved in water, and can evenly adhere to the chip surface. As the main body of the protective agent, it can also effectively reduce the friction and heat on the chip surface during the cutting process, reduce the friction between the cutting tool and the chip surface, thereby reducing the cutting force and thermal damage during the cutting process, and protect the chip surface from damage. Because it contains a large number of hydrophilic groups in its structure, it has good wettability and can effectively apply the cutting fluid to the chip surface, improving the uniformity and integrity of the coating. Without the addition of an additional leveling agent, it has the effect of preventing the coating from peeling and cracking. Other poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester) and poly(vinyl methyl ether-alt-maleic acid monobutyl ester) also have similar structures and properties to poly(vinyl methyl ether-alt-maleic acid monoethyl ester).

[0041] In some embodiments, the water-soluble resin has a number average molecular weight of 10,000 to 500,000. Using a water-soluble resin within this molecular weight range provides higher reactivity and a faster reaction rate, ensuring stability in aqueous solution and improving the coating effect of the protective liquid. Furthermore, the cutting protection liquid prepared with this molecular weight can form a protective film during the cutting process, effectively isolating the cutting tool from direct contact with the chip surface, reducing friction and impact during cutting, and preventing scratches, wear, and corrosion on the chip surface.

[0042] In some embodiments, the water-soluble resin is poly(vinyl methyl ether-alt-maleic acid monoethyl ester) having a number average molecular weight of 50,000 to 200,000.

[0043] In some embodiments, the improver is selected from at least one of difluoroethanol, trifluoroethanol, trichloroethanol, tribromoethanol, 2-chloro-2,2-difluoroethanol, and 2-fluoro-2-bromoethanol. Among them, the CAS number of difluoroethanol is 359-13-7, the CAS number of trifluoroethanol is 75-89-8, the CAS number of trichloroethanol is 115-20-8, the CAS number of tribromoethanol is 75-80-9, the CAS number of 2-chloro-2,2-difluoroethanol is 464-00-6, and the CAS number of 2-fluoro-2-bromoethanol is 459424-41-0. It is understood that the improver can be obtained through commercial means. Taking trifluoroethanol as an example, due to the high polarity of fluorine, the fluorine will selectively face upward during the evaporation process of the solvent, so the surface of the film layer formed by the cutting fluid is hydrophobic, which can repel the cutting water used in the cutting process of the cutter wheel.

[0044] In some embodiments, the adhesion promoter is selected from at least one of silane coupling agent KH580, trimethoxysilane, phenyltrimethoxysilane, silane coupling agent KH-550, and vinyltriethoxysilane. It should be noted that the adhesion promoter is primarily composed of silane coupling agents, which have excellent intermolecular interaction capabilities and can form an organic silicon layer on the chip surface, enhancing the adhesion of the cutting protection fluid to the chip surface. Furthermore, the silane coupling agent and the protective agent can cooperate with each other to improve their compatibility in the cutting fluid, which helps maintain wettability and adhesion, and enhances the uniform distribution and coverage of the cutting fluid on the chip surface, further improving the formation of the film layer on the chip surface.

[0045] In some embodiments, the defoamer is selected from at least one of propylene glycol fatty acid ester (CAS No. 1323-39-3), higher alcohol fatty acid ester, polyglycerol fatty acid ester (CAS No. 67784-82-1), and tributyl phosphate (CAS No. 126-73-8). Higher alcohol fatty acid ester is a mixture of stearic acid ester of octadecanol, liquid paraffin, triethanolamine stearate, and stearic acid. The defoamer can reduce or eliminate bubbles and foam in the cutting fluid and improve the stability of the cutting fluid. Eliminating bubbles and foam can prevent bubbles from hindering the effective contact between the cutting fluid and the chip surface during the cutting process, thereby ensuring the uniformity and stability of the cutting effect. In addition, the addition of the defoamer can improve the wetting ability of the cutting fluid and further improve the wetting effect of the cutting fluid on the chip surface. The defoamer itself has a certain surface activity and can work in conjunction with the protective agent to improve the wettability and dispersibility of the cutting fluid, so that the cutting fluid is better dispersed on the chip surface to form a uniform film layer.

[0046] In some embodiments, the present application provides a method for preparing a cutting protection liquid for a high-end CIS chip, comprising the following steps:

[0047] Take 30-130 parts of protective agent, 0.1-5 parts of adhesion promoter and 0.01-1 part of defoaming agent, heat to 90-105°C while stirring, and stir at constant temperature for 1.5-2.5 hours; then continue to heat to 135-145°C and stir at this temperature for 0.5-1 hour; finally cool to room temperature to obtain a uniform and transparent cutting protection liquid.

[0048] It should be noted that in the preparation method of the present application, a protective agent containing hydrophilic and hydrophobic structures is prepared by the curing reaction of a water-soluble resin and an improver. The protective agent can interact with other components, so that it is particularly suitable for protecting wafers cut with CIS image sensors and thereon, and has a variety of excellent properties, with broad application prospects and promotion value. The cutting protection liquid has few components (only three components), so the proportioning process is simple and easy to operate, and the cutting protection liquid of the present application has many advantages such as excellent film-forming and solubility properties, can prevent particles from contaminating the chip surface, has excellent protective adhesion, good protection of the cutting path, and the formed protective film is easy to clean and remove.

[0049] It should be further explained that the cutting protection liquid of this embodiment does not affect the normal use of the blue film on the back of the wafer, and the curing conditions of the protection liquid are mild, which is particularly suitable for the cutting protection of wafers with a blue film on the back. The components of the protection liquid are all low-toxic or harmless components, easy to recycle and discharge, with excellent environmental friendliness, and can achieve green production. In the cutting protection liquid of this embodiment, by selecting specific water-soluble resins and improvers, the water resistance time and adhesion of the film layer can be improved, and the residual particles on the chip surface can be reduced, thereby significantly improving the cutting yield of high-order CIS chips and improving the production effect and yield rate of the entire production line.

[0050] In some embodiments, the protective agent is prepared by a curing reaction of a water-soluble resin and an improver; the water-soluble resin and the improver are mixed and reacted; the mass ratio of the water-soluble resin to the improver is 10-30:20-100. For example, the mass ratio can be any ratio of 10:20, 20:20, 20:30, 20:40, 20:50, 20:60, 20:70, 20:80, 20:90, 20:100, 30:30, 30:50, 30:80, 30:100, or a range between any two ratios.

[0051] In some embodiments, the curing reaction temperature is 50-100° C., and the curing reaction time is 2-6 minutes. For example, the curing reaction temperature can be any one of 50° C., 60° C., 70° C., 80° C., 90° C., and 100° C., or a range between any two of these values; and the curing reaction time can be any one of 2 minutes, 3 minutes, 4 minutes, 5 minutes, and 6 minutes, or a range between any two of these values.

[0052] In some embodiments, the present application also provides the use of a cutting protection fluid in protecting high-end CIS chips during cutting. The cutting protection fluid has excellent film-forming properties, preventing particles from contaminating the chip surface. It also has excellent protective adhesion, provides good protection for the cutting path, and prevents cutting water from damaging the coating during the wheel cutting process. This makes it particularly suitable for protecting the cutting of high-precision, high-demand precision wafers.

[0053] In some embodiments, a method for protecting high-end CIS chips from cutting using the cutting protection liquid is provided, the method comprising the following steps:

[0054] Add 10-50 mL of protective solution to the surface of the high-order CIS chip and use a gel spinner to rotate at a speed of 500-1500 r / min for 30-60 seconds;

[0055] Bake the high-end CIS chip with the protective liquid spin-coated on the surface at 65-75°C for 60-90 minutes to solidify the film to form a protective layer;

[0056] The high-end CIS chip with a protective layer on its surface is cut and then cleaned before entering the next process.

[0057] The amount of the protective solution added can be any one of 10 mL, 20 mL, 30 mL, 40 mL, and 50 mL.

[0058] The rotation speed of the glue spreader is any one of 500r / min, 1000r / min, and 1500r / min; the rotation time is any one of 30s, 40s, 50s, and 60s.

[0059] The baking temperature is any value among 65°C, 70°C, and 75°C; the baking time is any value among 60min, 70min, 80min, and 90min.

[0060] Specific examples are further provided below, in which, unless otherwise specified, any ultrapure water used below is deionized water with a resistance ≥ 18 MΩ; since the water-soluble resin is a high molecular weight polymer, its molecular weight cannot be an accurate specific value, but rather a range value. For example, poly(vinyl methyl ether-alt-maleic acid monoethyl ester) with a molecular weight of 150,000 does not mean that its exact molecular weight is 150,000, but rather a range, and the range fluctuates within ±0.5 million.

[0061] Example 1

[0062] A cutting protection liquid for high-end CIS chips is provided, comprising the following components: 80 parts of a protective agent, 2.5 parts of a silane coupling agent KH580, and 0.5 parts of a propylene glycol fatty acid ester; the structure of the protective agent is shown in the following formula (1):

[0063]

[0064] Wherein, n represents the degree of polymerization, n=990; R1 is selected from ethyl; R2, R3, and R4 are independently selected from F.

[0065] The protective agent is prepared by polycondensation of poly(vinyl methyl ether-alt-maleic acid monoethyl ester) and trifluoroethanol, with a mass ratio of 20:60. The curing reaction temperature is 80° C. and the curing reaction time is 5 minutes.

[0066] The infrared spectrum of the protective agent is shown in the attached Figure 5 , of which 1712.03cm -1 The peak is the characteristic peak of the ester group produced by the dehydration condensation of carboxyl group and trifluoroethanol, indicating that the new protective agent has been successfully synthesized.

[0067] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0068] Poly(vinyl methyl ether-alt-maleic acid monoethyl ester) and trifluoroethanol in a mass ratio of 20:70 were cured at 70°C for 3 minutes to obtain a protective agent. The number average molecular weight of poly(vinyl methyl ether-alt-maleic acid monoethyl ester) was 200,000.

[0069] Take 80 parts of protective agent, 2.5 parts of silane coupling agent KH580 and 0.5 parts of propylene glycol fatty acid ester, add them to a container, heat to 100°C with stirring, stir at this constant temperature for 2 hours, raise the temperature to 140°C, stir at this temperature for another hour, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid A1.

[0070] Example 2

[0071] Provided is a cutting protection liquid for high-end CIS chips, comprising the following components: 130 parts of a protective agent, 4 parts of trimethoxysilane, and 0.8 parts of a polyglycerol fatty acid ester; the structure of the protective agent is shown in the following formula (1):

[0072]

[0073] wherein n represents the degree of polymerization, n=250; R1 is selected from isopropyl; R2 and R3 are selected from F, and R4 is selected from H. The specific preparation process of the protective agent is the same as that of Example 1.

[0074] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0075] Poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester) and difluoroethanol in a mass ratio of 30:100 were cured at 100°C for 2 minutes to obtain a protective agent. The number average molecular weight of the poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester) was 50,000.

[0076] Take 130 parts of protective agent, 4 parts of trimethoxysilane and 0.8 parts of polyglycerol fatty acid ester, add them to a container, heat to 90°C with stirring, stir at constant temperature for 2.5 hours, raise the temperature to 135°C, stir at constant temperature for 1 hour, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid A2.

[0077] Example 3

[0078] A cutting protection liquid for high-end CIS chips is provided, comprising the following components: 100 parts of a protective agent, 5 parts of phenyltrimethoxysilane, and 1 part of tributyl phosphate; the structure of the protective agent is shown in the following formula (1):

[0079]

[0080] wherein n represents the degree of polymerization, n=2500; R1 is selected from butyl; R2, R3, and R4 are independently selected from Cl. The specific preparation process of the protective agent is the same as that of Example 1.

[0081] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0082] Poly(vinyl methyl ether-alt-maleic acid monobutyl ester) and trichloroethanol in a mass ratio of 20:90 were cured at 70°C for 3 minutes to obtain a protective agent. The molecular weight of the poly(vinyl methyl ether-alt-maleic acid monobutyl ester) was 500,000.

[0083] Take 100 parts of protective agent, 5 parts of phenyltrimethoxysilane and 1 part of tributyl phosphate, add them to a container, heat to 105°C with stirring, stir at this constant temperature for 1.5 hours, raise the temperature to 145°C, stir at this temperature for 0.5 hours, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid A3.

[0084] Example 4

[0085] Provided is a cutting protection liquid for high-end CIS chips, comprising the following components: 30 parts of a protective agent, 0.1 parts of a silane coupling agent KH-550, and 0.01 parts of a high-carbon alcohol fatty acid ester; the structure of the protective agent is shown in the following formula (1):

[0086]

[0087] wherein n represents the degree of polymerization, n=990; R1 is selected from ethyl; R2, R3, and R4 are independently selected from Br. The specific preparation process of the protective agent is the same as that of Example 1.

[0088] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0089] Poly(vinyl methyl ether-alt-maleic acid monoethyl ester) and tribromoethanol in a mass ratio of 10:20 were cured at 70°C for 3 minutes to obtain a protective agent. The number average molecular weight of poly(vinyl methyl ether-alt-maleic acid monoethyl ester) was 200,000.

[0090] Take 30 parts of protective agent, 0.1 parts of silane coupling agent KH-550 and 0.01 parts of high-carbon alcohol fatty acid ester, add them to a container, heat to 100°C with stirring, stir at this constant temperature for 2 hours, raise the temperature to 140°C, stir at this temperature for another hour, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid A4.

[0091] Example 5

[0092] Provided is a cutting protection liquid for high-order CIS chips, comprising the following components: 110 parts of a protective agent, 1 part of vinyl triethoxysilane, and 0.2 parts of a propylene glycol fatty acid ester; the structure of the protective agent is shown in the following formula (1):

[0093]

[0094] wherein n represents the degree of polymerization, n=990; R1 is selected from ethyl; R2, R3, and R4 are independently selected from F, Cl, and F. The specific preparation process of the protective agent is the same as that of Example 1.

[0095] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0096] Poly(vinyl methyl ether-alt-maleic acid monoethyl ester) and 2-chloro-2,2-difluoroethanol in a mass ratio of 20:100 were cured at 70°C for 3 minutes to obtain a protective agent. The number average molecular weight of the poly(vinyl methyl ether-alt-maleic acid monoethyl ester) was 200,000.

[0097] Take 110 parts of protective agent, 1 part of vinyl triethoxysilane and 0.2 parts of propylene glycol fatty acid ester, add them to a container, heat to 100°C with stirring, stir at this constant temperature for 2 hours, raise the temperature to 140°C, stir at this temperature for another hour, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid A5.

[0098] Example 6

[0099] A cutting protection liquid for high-end CIS chips is provided, comprising the following components: 50 parts of a protective agent, 1.5 parts of a silane coupling agent KH580, and 0.3 parts of a propylene glycol fatty acid ester; the structure of the protective agent is shown in the following formula (1):

[0100]

[0101] wherein n represents the degree of polymerization, n=990; R1 is selected from ethyl; R2, R3, and R4 are independently selected from F, Br, and H. The specific preparation process of the protective agent is the same as that of Example 1.

[0102] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0103] Poly(vinyl methyl ether-alt-maleic acid monoethyl ester) and 2-fluoro-2-bromoethanol in a mass ratio of 30:30 were cured at 70°C for 3 minutes to obtain a protective agent. The number average molecular weight of poly(vinyl methyl ether-alt-maleic acid monoethyl ester) was 200,000.

[0104] Take 50 parts of protective agent, 1.5 parts of silane coupling agent KH580 and 0.3 parts of propylene glycol fatty acid ester, add them to a container, heat to 100°C with stirring, stir at this constant temperature for 2 hours, raise the temperature to 140°C, stir at this temperature for another hour, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid A6.

[0105] Comparative Example 1

[0106] Provided is a cutting protection liquid for high-order CIS chips, comprising the following components: 80 parts of polymethyl vinyl ether maleic anhydride alternating copolymer, 2.5 parts of silane coupling agent KH580, and 0.5 parts of propylene glycol fatty acid ester.

[0107] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0108] Take 80 parts of polymethyl vinyl ether maleic anhydride alternating copolymer, 2.5 parts of silane coupling agent KH580 and 0.5 parts of propylene glycol fatty acid ester, add them to a container, heat to 100°C with stirring, stir at this constant temperature for 2 hours, raise the temperature to 140°C, stir at this temperature for another hour, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid B1.

[0109] Comparative Example 2

[0110] Provided is a cutting protection liquid for high-order CIS chips, comprising the following components: 80 parts of poly(vinyl methyl ether-alt-maleic acid monoethyl ester), 2.5 parts of a silane coupling agent KH580, and 0.5 parts of a propylene glycol fatty acid ester; the poly(vinyl methyl ether-alt-maleic acid monoethyl ester) is directly obtained from the market.

[0111] The preparation method of cutting protection liquid for high-end CIS chips is as follows:

[0112] Take 80 parts of poly(vinyl methyl ether-alt-maleic acid monoethyl ester), 2.5 parts of silane coupling agent KH580 and 0.5 parts of propylene glycol fatty acid ester, add them to a container, heat to 100°C with stirring, stir at this constant temperature for 2 hours, raise the temperature to 140°C, stir at this temperature for 1 hour, and then cool to room temperature to obtain a uniform, transparent light yellow liquid, which is cutting protection liquid B2.

[0113] The cutting protection liquid prepared in Examples 1-6 and Comparative Examples 1-2 is used for cutting protection of high-order CIS chips. The specific process is: 30 mL of cutting protection liquid is added dropwise to the surface of the high-order CIS chip, and a coating machine is used to rotate at a speed of 1000 r / min for 50 seconds; the high-order CIS chip with the protection liquid spin-coated on the surface is baked at 70°C for 80 minutes to solidify the film to form a protective layer; the high-order CIS chip with the protective layer on the surface is cut, and then cleaned and enters the next process.

[0114] The high-end CIS chips after being processed in various embodiments and comparative examples were tested, and the specific data are shown in Table 1.

[0115] Testing includes:

[0116] The CIS chip's cutter wheel protection test steps are as follows:

[0117] A cutting protection liquid was spin-coated on the surface of a 12-inch wafer and cut using a high-speed rotating diamond blade to form an independent single crystal. After cleaning with a blade wheel cleaning agent, the surface cleanliness of the single crystal and the presence of silicon powder particles were observed under an optical microscope. The obtained cutting protection performance is shown in the following figure and Table 1.

[0118] Wafer yield test, the steps are as follows:

[0119] A cutting protection fluid is spin-coated on the wafer surface and then cut with a high-speed diamond blade to form individual single crystals. Automatic optical inspection equipment is used to count the number of qualified wafers after cutting and calculate the yield rate. The yield rates for wafers using different cutting protection fluids are shown in Table 1 below. Yield rate = number of qualified wafers / total number of wafers.

[0120] Figure 1 The cutting protection liquid A1 of Example 1 is applied. A microscope photograph of the photosensitive area of ​​the high-end CIS chip after cutting is magnified 164 times. It can be clearly seen that there are no foreign particles on the photosensitive area, thus having very excellent cutting protection.

[0121] When the cutting protection liquid B2 of comparative example 2 is used for protection, the wafer with the high-order CIS chip thereon is directly laser cut, and then the microscope photograph obtained by magnifying the photosensitive area by 164 times is shown in FIG. Figure 2 .from Figure 2 It can be clearly seen that there are many foreign particles on the photosensitive area (see multiple white bright spots). When there are foreign particles larger than 0.7 microns on the photosensitive area, the chip will be deemed an unqualified product. These particles cannot be completely removed by the current cleaning method, resulting in a significant reduction in product yield and inability to achieve large-scale and industrial production.

[0122] The adhesion performance test of the protective layer after the protective liquid is cured is as follows:

[0123] Spin-coat the cutting protection liquid on the wafer surface, use a high-speed rotating diamond blade to cut the wafer, and take a microscope photo of the cutting path magnified 200 times; Figure 3 The two white cross lines in the figure are cutting lanes. It can be seen that the edge of the protective layer formed by the cutting protection liquid A1 of Example 1 completely and tightly overlaps with the edge of the cutting lane, thereby effectively covering the edge of the chip and protecting it from contamination by impurities such as cutting debris and particles. Figure 4 After cutting, the edge of the protective layer obviously expands outward along the cutting line. The cutting protection liquid B2 of comparative example 2 fails to completely cover the edge of the chip after cutting, resulting in the uncovered chips around the cutting line being easily contaminated by various debris and particles.

[0124] The hydrophobicity performance test steps are as follows:

[0125] The cutting protection liquid is spin-coated on the wafer surface, and the contact angle is tested by a contact angle meter. The hydrophobicity of the film layer is determined by the size of the contact angle of the liquid droplet on the film surface.

[0126] Table 1

[0127]

[0128]

[0129] As can be seen from Table 1, the cutting protection liquid prepared by using Examples 1-6 has a high yield of more than 96%, a large contact angle, and good wettability. Comparative Example 1 uses a conventional protection liquid. Although it can prevent particles from contaminating the chip surface and has a certain protective adhesion, its contact angle is only 52.4°, and the chip yield is reduced; and Comparative Example 2 uses an unmodified protective agent, the protective adhesion is reduced, so that the chip avoids more particulate matter residues, and the corresponding contact angle and chip yield are reduced.

[0130] The above is a detailed introduction to the cutting protection liquid for high-end CIS chips, its preparation method and use provided in the embodiments of the present application. Specific examples are used in this application to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application; ordinary technicians in this field should understand that: they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements 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 application.

Claims

1. A cutting protection liquid for high-end CIS chips, characterized in that: The invention comprises the following components in parts by mass: 30-130 parts of a protective agent, 0.1-5 parts of an adhesion promoter and 0.01-1 parts of a defoaming agent; the structure of the protective agent is shown in the following formula (1): Wherein, n represents the degree of polymerization; R1 is selected from any one of ethyl, isopropyl and butyl; R2, R3 and R4 are independently selected from one or more of F, Cl, Br and H.

2. The cutting protection liquid for high-end CIS chips according to claim 1, characterized in that: The protective agent is prepared from a water-soluble resin and an improver; wherein the structure of the water-soluble resin is shown in the following formula (2), and the structure of the improver is shown in the following formula (3); 3. The cutting protection liquid for high-end CIS chips according to claim 2, characterized in that: The water-soluble resin is selected from at least one of poly(vinyl methyl ether-alt-maleic acid monoethyl ester), poly(vinyl methyl ether-alt-maleic acid monoisopropyl ester), and poly(vinyl methyl ether-alt-maleic acid monobutyl ester); The improver is selected from at least one of difluoroethanol, trifluoroethanol, trichloroethanol, tribromoethanol, 2-chloro-2,2-difluoroethanol, and 2-fluoro-2-bromoethanol.

4. The cutting protection liquid for high-end CIS chips according to claim 2, characterized in that: The number average molecular weight of the water-soluble resin is 10,000-500,000.

5. The cutting protection liquid for high-end CIS chips according to claim 1, characterized in that: The adhesion promoter is selected from at least one of silane coupling agent KH580, trimethoxysilane, phenyltrimethoxysilane, silane coupling agent KH-550, and vinyltriethoxysilane.

6. The cutting protection liquid for high-end CIS chips according to claim 1, characterized in that: The defoaming agent is selected from at least one of propylene glycol fatty acid ester, higher alcohol fatty acid ester, polyglycerol fatty acid ester and tributyl phosphate.

7. The method for preparing a cutting protection liquid for a high-end CIS chip according to any one of claims 1 to 6, characterized in that: The following steps are involved: Take 30-130 parts of protective agent, 0.1-5 parts of adhesion promoter and 0.01-1 part of defoaming agent, heat to 90-105°C while stirring, and stir at constant temperature for 1.5-2.5 hours; then continue to heat to 135-145°C and stir at this temperature for 0.5-1 hour; finally cool to room temperature to obtain a uniform and transparent cutting protection liquid.

8. The method for preparing a cutting protection liquid for a high-end CIS chip according to claim 7, characterized in that: The protective agent is prepared by a curing reaction of a water-soluble resin and an improver; wherein the mass ratio of the water-soluble resin to the improver is 10-30:20-100.

9. The method for preparing a cutting protection liquid for a high-end CIS chip according to claim 8, characterized in that: The curing reaction temperature is 50-100°C, and the curing reaction time is 2-6 minutes.

10. Use of the cutting protection liquid according to any one of claims 1 to 6 in cutting protection of high-end CIS chips.

Images