CN116004072B

CN116004072B - Composition, preparation method and application thereof in wafer laser cutting

Info

Publication number: CN116004072B
Application number: CN202211675936.5A
Authority: CN
Inventors: 侯军; 马超男; 褚雨露; 张楠
Original assignee: Zhejiang Aoshou Material Technology Co ltd
Current assignee: Zhejiang Aoshou Material Technology Co ltd
Priority date: 2022-12-26
Filing date: 2022-12-26
Publication date: 2024-04-02
Anticipated expiration: 2042-12-26
Also published as: CN116004072A

Abstract

The application discloses a composition, a preparation method and application thereof in wafer laser cutting, wherein the composition comprises the following components in parts by mass: 20-35 parts of water-soluble resin; 0.05-0.3 part of leveling agent; 0.1-0.5 part of ultraviolet absorber; 0.1-3 parts of corrosion inhibitor; 2-10 parts of plasticizer; 45-70 parts of organic solvent; 15-30 parts of deionized water; wherein the water-soluble resin comprises hydrophilic groups, and the hydrophilic groups are selected from any one or more of hydroxyl groups, amide groups and carboxyl groups. The application adopts the water-soluble resin with amide groups, hydroxyl groups, carboxyl groups and other hydrophilic groups and with the molecular weight of 50000-80000, improves the film forming property of the composition on the surface of a wafer, can adapt to wafer substrates with different shapes, and can be dissolved by water and quickly cleaned and removed after the cutting process is finished due to the existence of the hydrophilic groups, thereby greatly improving the efficiency of the preparation process.

Description

Composition, preparation method and application thereof in wafer laser cutting

Technical Field

The application belongs to the technical field of chip packaging, and particularly relates to a composition, a preparation method and application.

Background

In order to avoid the damage to the substrate silicon wafer caused by laser cutting, a protective liquid needs to be coated on the surface of the substrate to form a protective film before laser processing, so that the chip can be well protected in the processing process; the existing protective liquid for laser cutting has the defects of high viscosity, inconvenient coating, incomplete protection of flip chip wafers containing concave-convex structures and incapability of protecting the concave-convex structures from being polluted or corroded.

Disclosure of Invention

Application purpose: the present application provides a high solids, low viscosity composition to improve yield and productivity in semiconductor manufacturing processes; it is another object of the present application to provide a method of preparing a composition; it is another object of the present application to provide a use of the composition.

The technical scheme is as follows: a composition of the present application comprising, in parts by mass:

20-35 parts of water-soluble resin; 0.05-0.3 part of leveling agent; 0.1-0.5 part of ultraviolet absorber; 0.1-3 parts of corrosion inhibitor; 2-10 parts of plasticizer; 45-70 parts of organic solvent; 15-30 parts of deionized water;

the water-soluble resin comprises a hydrophilic group, wherein the hydrophilic group is at least one selected from hydroxyl, amido and carboxyl.

In some embodiments, the composition comprises:

25-30 parts of water-soluble resin; 0.05-0.1 part of leveling agent; 0.2-0.3 part of ultraviolet absorber; 1-2 parts of corrosion inhibitor; 2-5 parts of plasticizer; 60-70 parts of organic solvent; 15-20 parts of deionized water.

In some embodiments, the water-soluble resin is prepared from a first monomer and a second monomer by copolymerization; wherein the first monomer is selected from compounds with side groups containing at least one of the hydroxyl, the amide and the carboxyl, and the second monomer is selected from compounds with side groups containing at least one of the hydroxyl, the amide and the carboxyl.

In some embodiments, the first monomer is selected from compounds having pendant groups containing the amide groups, and the second monomer is selected from compounds having pendant groups containing the hydroxyl groups; or alternatively

The first monomer is selected from compounds with side groups containing the amide groups, and the second monomer is selected from compounds with side groups containing the carboxyl groups; or alternatively

The first monomer is selected from compounds with side groups containing the amide groups, the second monomer is selected from compounds with side groups containing the amide groups, and the second monomer and the first monomer are respectively different compounds.

In some embodiments, the first monomer is selected from at least one of benzamide, acrylamide, N-dimethylformamide, and the second monomer is selected from at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate; or alternatively

The first monomer is at least one selected from benzamide, acrylamide and N, N-dimethylformamide, and the second monomer is at least one selected from acrylic acid, methacrylic acid, maleic anhydride and itaconic acid;

the first monomer is selected from at least one of benzamide, acrylamide and N, N-dimethylformamide, the second monomer is selected from at least one of benzamide, acrylamide and N, N-dimethylformamide, and the first monomer and the second monomer are respectively different compounds.

In some embodiments, the first monomer and the second monomer are copolymerized in a mass ratio of 25 (5-10).

In some embodiments, the water-soluble resin has a molecular weight of 50000 to 80000.

In some embodiments, the leveling agent is selected from at least one of polyether modified silicone, polyester modified silicone, end group modified silicone; and/or

The ultraviolet absorbent is at least one selected from ferulic acid, 2-hydroxy-4-n-octoxybenzophenone, 2, 4-dihydroxybenzophenone and 2-hydroxy-4-diethylamino-2-carboxybenzophenone; and/or

The corrosion inhibitor is at least one selected from cyclohexylamine, sodium silicate and sodium benzoate; and/or

The plasticizer is at least one selected from glycerol, 1, 3-butanediol and polyethylene glycol.

In some embodiments, the present application also provides a method of preparing a composition comprising: respectively weighing water-soluble resin, flatting agent, ultraviolet absorbent, corrosion inhibitor, plasticizer, organic solvent and deionized water in parts by weight, mixing and stirring to prepare a composition; wherein the stirring speed is 200-500 rpm; the stirring time is 1-5 h.

In some embodiments, the application also provides the use of the composition as a laser cut protective material in laser cutting of wafers.

The beneficial effects are that: compared with the prior art, the composition comprises the following components in parts by mass: 20-35 parts of water-soluble resin; 0.05-0.3 part of leveling agent; 0.1-0.5 part of ultraviolet absorber; 0.1-3 parts of corrosion inhibitor; 2-10 parts of plasticizer; 45-70 parts of organic solvent; 15-30 parts of deionized water; wherein the water-soluble resin comprises hydrophilic groups, and the hydrophilic groups are selected from any one or more of hydroxyl groups, amide groups and carboxyl groups. The application adopts the water-soluble resin with amide groups, hydroxyl groups, carboxyl groups and other hydrophilic groups and with the molecular weight of 50000-80000, improves the film forming property of the composition on the surface of a wafer, can adapt to wafer substrates with different shapes, and can be dissolved by water and quickly cleaned and removed after the cutting process is finished due to the existence of the hydrophilic groups, thereby greatly improving the efficiency of the preparation process.

The water-soluble resin is prepared by copolymerizing monomers containing amide groups, hydroxyl groups, carboxyl groups and other side groups, and the side groups can be slightly crosslinked in the copolymerization process to enable the water-soluble resin to have a network structure, so that the strength and elasticity of the resin are further improved, the adhesive force of the resin is also enhanced, and the wafer substrate can be firmly protected.

The composition of the application is also added with the leveling agent, the leveling agent can be perfectly compatible with the water-soluble resin solution, the defects of shrinkage cavity, orange peel and the like are prevented, the lubricity and glossiness of the surface of the wafer can be improved, and the film is smooth and bright like a mirror, uniform and transparent.

It is understood that, compared with the prior art, the preparation method of the composition and the application of the composition provided in the embodiments of the present application have all technical features and beneficial effects of the composition described above, and are not described herein again.

Drawings

Technical solutions and other advantageous effects of the present application will be made apparent from the following detailed description of specific embodiments of the present application with reference to the accompanying drawings.

FIG. 1 is a wafer pattern of bump structures after application of the composition of example 1 of the present application;

FIG. 2 is a microscopic photograph of a bump structure wafer at 350 times magnification after application of the composition of example 1 of the present application;

FIG. 3 is a microscopic image at 500 magnification of a bump structure wafer after application of the composition of example 1 of the present application;

FIG. 4 is a microscopic image at 800 magnification of a bump structure wafer after coating with the composition of comparative example 1 of the present application;

FIG. 5 is an infrared spectrum of a water-soluble resin prepared in example 1 of the present application by copolymerizing acrylamide and hydroxyethyl methacrylate;

FIG. 6 is a photograph of the composition of example 1 of the present application after being subjected to a hundred test;

FIG. 7 is a photograph of the composition of comparative example 1 of the present application after being subjected to a hundred-gram test;

fig. 8 is a photograph of the composition of comparative example 2 of the present application after being subjected to a hundred-gram test.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "connected," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features.

The following disclosure provides many different embodiments or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present application.

Flip chips (Flip chips) are a technology of depositing tin-lead balls on I/O pads (Chip pin processing modules), and then Flip-Chip heating to replace conventional wire bonding by combining the molten tin-lead balls with a ceramic substrate, and gradually become the mainstream of future packaging. With the continuous expansion of the microelectronic market, the improvement of the productivity, efficiency and yield of products becomes the primary problem at present; in the cutting process of many small chips, a diamond dicing blade is generally adopted, and a cutter rotating at a high speed is utilized to drive a blade arranged on the cutter to cut the cut chips, so that a separation action is realized; in some high-hardness chip cutting, laser is used for cutting the grooves in advance, and the laser ablation processing has the balance among efficiency, qualification rate and cost. However, as the feature size of the semiconductor integrated circuit is continuously reduced, impurities such as a wax layer, dirt and circuit oxidation residues are easily left on the surface of the chip during the separation operation, and the residual impurities contain active oxidation components which adhere to the surface of the chip for a long time, so that substances on the surface of the chip are easily oxidized, and even the phenomenon of edge breakage is likely to be caused under the action of the gravity of dirt impurities.

Therefore, in order to avoid the problem of damage to the substrate silicon wafer caused by laser cutting, and to improve the yield of semiconductor products and the cutting efficiency, a protective film needs to be formed by coating a protective liquid on the surface of the substrate before laser processing, so that other areas of the chip can be well protected in the processing process to inhibit adhesion of fragments on the surface of the wafer, and the requirements of narrow cutting channel and miniaturization of the chip are met as far as possible besides the requirements of cutting protection of sapphire, gallium arsenide, silicon carbide, semiconductor wafers and the like.

The applicant found that the prior disclosed laser cutting protection liquid has high viscosity, is inconvenient to coat, affects the use of the liquid, and can not completely protect Flip chip (Flip chip) wafers containing concave-convex structures from being polluted or corroded. Therefore, there is a need to develop a laser cutting protection liquid with low viscosity and capable of protecting the concave-convex structure.

Based on the above problems, the embodiments of the present application provide a composition, which includes, in parts by mass:

20-35 parts of water-soluble resin; 0.05-0.3 part of leveling agent; 0.1-0.5 part of ultraviolet absorber; 0.1-3 parts of corrosion inhibitor; 2-10 parts of plasticizer; 45-70 parts of organic solvent; 15-30 parts of deionized water; wherein the water-soluble resin comprises hydrophilic groups, and the hydrophilic groups are selected from any one or more of hydroxyl groups, amide groups and carboxyl groups.

In some embodiments, preferably, the composition comprises:

In some embodiments, the present embodiments provide a high solids, low viscosity composition that can protect the relief structure of a wafer, improving yield and productivity in the semiconductor manufacturing process. The composition has amide groups, hydroxyl groups, carboxyl groups and other hydrophilic groups, has molecular weight of 50000-80000, improves film forming property of the composition on the surface of a wafer, can adapt to wafer substrates with different shapes, and can be dissolved by water and quickly cleaned and removed after the cutting process is finished due to the existence of the hydrophilic groups, so that the efficiency of the preparation process is greatly improved. The preferred molecular weight is further 60000-70000.

In some embodiments, the water-soluble resin is prepared from the first monomer and the second monomer by copolymerization; wherein the first monomer is selected from compounds with side groups containing any one or more of hydroxyl, amido and carboxyl, and the second monomer is selected from compounds with side groups containing any one or more of hydroxyl, amido and carboxyl. Further preferably, the first monomer is selected from amide group-containing compounds on the side groups, and the second monomer is selected from hydroxyl group-containing compounds on the side groups; or the first monomer is selected from compounds with side groups containing amide groups, and the second monomer is selected from compounds with side groups containing carboxyl groups; or the first monomer is selected from compounds with amide groups on side groups, and the second monomer and the first monomer are respectively different compounds at the moment so as to ensure that copolymerization reaction between the two compounds occurs.

In some embodiments, copolymerization refers to a reaction in which two or more compound monomers are polymerized into one species under certain conditions. The purpose of the copolymerization is to increase the diversity of hydrophilic groups contained in the water-soluble resin, and particularly, more hydrophilic groups can be introduced after the copolymerization of monomers containing different hydrophilic groups, and the hydrophilic groups can participate in the reaction to generate salt, so that the resin obtains water solubility. Of course, in some other embodiments, the water-soluble resin may be obtained by polymerizing a compound monomer having a hydrophilic group with a single side group, or may be obtained directly by homopolymerizing a compound monomer, for example, by polymerizing a compound monomer having the same carboxyl group, and the water-soluble resin obtained by this polymerization may also provide excellent water solubility under the action of the hydrophilic group.

In some embodiments, to achieve protection of the wafer substrate, film forming properties are critical to the composition to achieve protection of the wafer surface, the higher the film forming properties, the easier the composition spreads on the substrate surface, especially for substrates with relief structures; film forming property is related to molecular weight of water-soluble resin or viscosity of composition, and hydrophilicity of water-soluble resin directly affects viscosity of final composition, so that in order to improve spreading effect of surface, on one hand, molecular weight of water-soluble resin needs to be controlled within a certain range, on the other hand, a large amount of hydrophilic groups on water-soluble resin needs to be ensured, and viscosity of composition is reduced under the condition of not changing solid content by controlling the two. In addition, the water-soluble resin has more hydrophilic groups due to the preparation process of copolymerization, so that the film forming property of the water-soluble resin is more excellent compared with that of the resin subjected to single homopolymerization.

In some embodiments, the molecular structure of the water-soluble resin may be any one or more of random copolymerization, block copolymerization, alternating copolymerization, and graft copolymerization, with the specific molecular structure being based on the monomers actually involved in polymerization and the polymerization conditions.

In some embodiments, the first monomer is selected from any one or more of benzamide, acrylamide, N-dimethylformamide, and the second monomer is selected from any one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate.

In some embodiments, the first monomer is selected from any one or more of benzamide, acrylamide, N-dimethylformamide, and the second monomer is selected from any one or more of acrylic acid, methacrylic acid, maleic anhydride, and itaconic acid.

In some embodiments, the first monomer is selected from the group consisting of benzamides and the second monomer is selected from the group consisting of acrylamides; or the first monomer is selected from benzamide, and the second monomer is selected from N, N-dimethylformamide; or the first monomer is selected from acrylamide and the second monomer is selected from N, N-dimethylformamide.

In some embodiments, the first monomer may also be selected from any one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, and the second monomer may also be selected from any one or more of benzamide, acrylamide, N-dimethylformamide.

In some embodiments, the first monomer may also be selected from any one or more of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, and the second monomer may also be selected from any one or more of acrylic acid, methacrylic acid, maleic anhydride, and itaconic acid.

In some embodiments, a slight cross-linking may also be generated during the copolymerization of the first and second monomers, it being understood that the cross-linking is only one reaction condition occurring during the polymerization, and the purpose of the cross-linking is to increase the strength of the resin, but the cross-linking does not affect the overall properties of the resin, particularly the viscosity of the resin, so that in the selection of the co-monomers, it is necessary to ensure a large amount of hydrophilic groups to increase the water solubility of the resin, while some slight cross-linking between hydrophilic groups may also be generated to increase the strength. Most preferred combination is that the first monomer is selected from acrylamide, the second monomer is selected from hydroxyethyl methacrylate, and acrylamide and hydroxyethyl methacrylate are adopted because the two monomers belong to crosslinking monomers, and a net structure can be formed after polymerization, so that the strength and elasticity of the resin are improved, but the viscosity of the resin is not reduced, the adhesive force of the resin can be enhanced, and the base material can be firmly protected. Of course, the monomers that can produce crosslinking are not limited to the above, as long as other monomers that meet the reaction requirements are also within the scope of the present application.

In some embodiments, the mass ratio of the first monomer to the second monomer is 25 (5-10). Specifically, the mass ratio of the first monomer to the second monomer may be in a range between any one or any two of 25:5, 25:6, 25:7, 25:8, 25:9, 25:10.

In some embodiments, the molecular weight of the water-soluble resin is 50000-80000. Specifically, the molecular weight of the water-soluble resin may be in a range between any one or any two of 50000, 55000, 60000, 65000, 70000, 75000, 80000.

In some embodiments, the method for preparing the water-soluble resin comprises the following specific steps:

under the protection of nitrogen, adding the first monomer and the second monomer into a solvent, adding an initiator, transferring into a reaction kettle, and heating the reaction kettle to 50-110 ℃, preferably 75-85 ℃ and most preferably 80 ℃; heating and stirring the reactants for a reaction time of 2-48 hours, preferably 6-8 hours, and most preferably 7 hours; the water-soluble resin is prepared. Wherein the solvent is water and absolute ethanol with the mass ratio of 1:1500-1:500, preferably 1:1000-1:500, most preferably 1:1100; the initiator may be azobisisobutyronitrile, azobisisoheptonitrile, benzoyl peroxide, ammonium persulfate, etc., preferably azobisisobutyronitrile, benzoyl peroxide, most preferably azobisisobutyronitrile; the first monomer is preferably selected from hydroxyethyl methacrylate, and the second monomer is preferably selected from acrylamide; preferably the mass ratio of the copolymerization is 25:7.

In some embodiments, the leveling agent is selected from any one or more of polyether modified silicones, polyester modified silicones, end group modified silicones; wherein the polyether modified organosilicon comprises RF-7333, BYK-333 and the like, the polyester modified organosilicon comprises BYK310, BYK3770 and the like, and the end group modified organosilicon comprises MONENG-1060; polyether modified silicone BYK-333 is preferred. The polyether leveling agent has good controlled compatibility with the aqueous system, and if the compatibility is too good, the leveling agent is completely dissolved in the resin, so that a new interface is not formed on the film forming surface, and no leveling effect is provided; the compatibility is poor, the coating film cannot be uniformly distributed in the water-soluble resin, the coating film and the water-soluble resin are mutually aggregated, shrinkage cavity defects are easy to generate, the gloss of the coating film is reduced, bad side effects such as fog images are generated, a new interface layer is formed on the film-forming surface only by ideal controlled compatibility, the leveling effect is realized, and BYK-333 is most preferably matched with the water-soluble resin, and the storage stability of the system is improved. The addition of the leveling agent can obviously improve the fluidity of the composition, improve the wettability of the base material, reduce shrinkage cavities and fish eyes, further avoid Benard vortex and silk threads, and reduce the sensitivity to hot air flow. Meanwhile, the organosilicon leveling agent can endow the formed protective film with different degrees of smoothness, particularly the phenomenon that the solvent volatilizes in the centrifugal diffusion process of the composition, the resin content in the composition can be locally uneven, so that the cohesion of the surface of the composition is uneven, the composition diffuses irregularly on the surface of a substrate, and the leveling agent and a large amount of hydrophilic groups in the water-soluble resin cooperate with each other, so that the dispersion uniformity of the resin can be improved, the diffusion of the composition is promoted, and a uniform protective film is formed on the surface of the substrate.

In some embodiments, the ultraviolet absorber is selected from any one or more of ferulic acid, 2-hydroxy-4-n-octoxybenzophenone, 2, 4-dihydroxybenzophenone, 2-hydroxy-4-diethylamino-2-carboxybenzophenone; the ultraviolet absorber is a light stabilizer capable of absorbing ultraviolet light in sunlight and fluorescent light without itself being changed.

In some embodiments, the corrosion inhibitor is selected from any one or more of cyclohexylamine, sodium silicate, sodium benzoate; corrosion inhibitors, when present in the composition in a suitable concentration and form, can prevent or slow the corrosion of the composition.

In some embodiments, the plasticizer is selected from any one or more of glycerol, 1, 3-butanediol, polyethylene glycol. The polyethylene glycol further may include polyethylene glycol 200, polyethylene glycol 400, polyethylene glycol 600. The addition of the plasticizer can further weaken the van der Waals force among polymer molecules, thereby increasing the mobility of polymer molecular chains and properly improving the film forming property of the composition.

In some embodiments, the organic solvent is selected from any one or a combination of any plurality of alcohols, ethers, and esters. Wherein the alcohol can be methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, isobutanol; the ether may be any one or more of diethyl ether, methyl ethyl ether, di-n-butyl ether, propylene glycol methyl ether, and ethylene glycol propyl ether; the ester may be, for example, any one or more of ethyl acetate, n-butyl acetate, and the like. The organic solvent is most preferably propylene glycol methyl ether or ethanol or any combination of the two.

In some embodiments, the composition of the present application can achieve the effects of improving adhesion and inhibiting corrosion by adding an ultraviolet absorber, a corrosion inhibitor and a plasticizer; the ultraviolet absorber and the plasticizer are added, so that the ultraviolet absorber and the plasticizer can realize respective functions, and the adhesive force performance can be further improved due to the action between the ultraviolet absorber and the plasticizer, so that a synergistic effect is achieved, and the function of the plasticizer is realized under the condition that the function of the ultraviolet absorber is ensured.

In some embodiments, a method of preparing a composition comprises: respectively weighing water-soluble resin, flatting agent, ultraviolet absorbent, corrosion inhibitor, plasticizer, organic solvent and deionized water in parts by weight, mixing and stirring to prepare a composition; wherein the stirring speed is 200-500 rpm; stirring time is 1-5 h.

In some embodiments, the stirring speed may be any value or range between any two values of 200rpm, 300rpm, 400rpm, 500rpm; the stirring time may be any value or range between any two values of 1h, 2h, 3h, 4h or 5h.

In some embodiments, there is further provided the use of a composition as a laser cut protection material in laser cutting of wafers.

In some embodiments, the specific application process is: firstly, cleaning wafers with different sizes to be coated; setting a spin coating program, dripping cutting protection materials on a wafer, and spin-coating for 2 minutes at 1000rpm, wherein the dosage of the cutting protection materials is 10ml/4 inch, 15ml/6 inch, 25ml/8 inch and 35ml/12 inch; after spin coating, the method can be used for carrying out the next laser cutting process. By adopting the composition of the embodiment, a layer of protective film can be formed on the surface of the wafer to ensure that the wafer is not scratched by fragments in the cutting process, thereby improving the yield of semiconductor products and the cutting efficiency.

The 12 compositions were formulated separately and the specific components of each of the compositions of examples 1-12 are given in Table 1. The preparation method of the specific composition is the same, and the composition is obtained by mixing the components and stirring at the speed of 300rpm for 3 hours at the normal temperature, wherein the normal temperature is 25 ℃.

Table 2 shows the copolymerization mass ratios and molecular weights of the water-soluble resins provided in examples 1 to 12.

Examples	Copolymerization mass ratio	Molecular weight
			1	Acrylamide hydroxyethyl methacrylate=25:7	60000
2	Acrylic acid hydroxyethyl methacrylate=25:5	50000
			3	Methacrylic acid hydroxyethyl methacrylate=25:6	55000
4	Maleic anhydride, hydroxyethyl methacrylate=25:7	65000
			5	Itaconic acid/hydroxyethyl methacrylate=25:8	70000
6	Acrylic acid methacrylic acid=25:9	75000
			7	Maleic anhydride, itaconic acid=25:10	80000
8	Acrylic acid, itaconic acid=25:5	50000
			9	Acrylamide hydroxyethyl acrylate=25:6	55000
10	Acrylamide benzamide=25:7	60000
			11	Acrylamide methacrylic acid=25:8	70000
12	Acrylamide, itaconic acid=25:10	80000

Based on examples 1-12, further comparative examples are provided, with specific components of the comparative example compositions, see Table 3, prepared in the same manner as examples 1-12.

TABLE 3 Table 3

The compositions of examples 1-12 and comparative examples 1-10 were subjected to performance testing, with specific results being shown in Table 4.

The test properties include viscosity, solids content and adhesion.

Viscosity measurement

The viscosity was measured using an NDJ-5S model rotational viscometer, with a speed of 20-50 set at 100rpm; the viscosity is 50-100, and the rotating speed is 50rpm; the viscosity was set at 100-200 and the rotational speed was set at 10rpm.

Solid content determination

1. Aluminum cup [ W ] ₀ ]Placing the balance on the balance, initializing the balance to the second decimal point, and adjusting and displaying to be 0;

2. the composition was poured into an aluminum cup of 10g or more, and the initial weight [ W ] of the solution was measured with a balance ₁ ]；

3. Moving the aluminum cup onto a hot plate, starting the hot plate, heating the solution (170 ℃/30 min) without allowing the boiling composition to fly outside the aluminum cup, and evaporating the solvent;

4. after evaporation of the solvent, the aluminum cup is placed on a balance and the balance [ W ] is weighed ₂ ]The weight of the aluminum cup was removed from the remaining amount, and the residue weight [ W ] was calculated ₂ -W ₀ ]；

5. Based on the initial weight of the solution [ W ₁ ]And residue weight [ W ₂ -W ₀ ]Calculating the concentration of the solid component; the solid content calculation method comprises the following steps: solid content= ([ W) ₂ -W ₀ ]/W ₁ )×100％。

Adhesion test

After obtaining the compositions of the above examples, 25ml of the composition was dropped onto a bare silicon wafer, which was then coated with a spin coater at a spin speed of 1000rpm for 120s, and dried to form a film, and the adhesion was tested by the hundred method. Adhesion level determination criteria: level 0: a piece of coating is peeled off at the edge and the intersection point of the scribing line, and the total peeled-off area is more than 65%; stage 1: a piece of coating is dropped off at the edge and the crossing point of the scribing line, and the total dropping area is between 35 percent; 2 stages: a piece of coating is dropped off at the edge and the crossing point of the scribing line, and the total dropped-off area is between 15 and 35 percent; 3 stages: the small piece of coating is dropped off at the edge and the crossing point of the scribing, and the total dropped-off area is between 5 and 15 percent; 4 stages: the small piece of coating is peeled off at the cross point of the scribing line, and the total peeling area is less than 5%;5 stages: the scribing edge is smooth, and no coating is dropped off at the scribing edge and the intersection point.

TABLE 4 Table 4

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From the test results of examples 1 to 12, it is known that when the water-soluble resin employs the monomer having hydrophilic group defined in the present application and employs two monomers for copolymerization, the molecular weight of the composition can be ensured within the prescribed required range, the interaction between a large number of different types of hydrophilic groups can be ensured, the film forming property of the composition on the wafer surface can be improved, so as to achieve complete coating on the wafer surface, and meanwhile, the side groups can be slightly crosslinked during the copolymerization process to enable the water-soluble resin to have a network structure, so that the strength and elasticity of the resin can be further improved, the adhesive force of the resin can be enhanced, and the wafer substrate can be firmly protected.

From the test results of example 1, comparative example 1 and comparative example 2, when the water-soluble resin was prepared using a single system of monomers, the water-soluble resin was inferior in performance due to the small number of hydrophilic groups upon polymerization, and the composition was made to have a high viscosity and a low adhesion, which would seriously affect the application of the composition as a protective liquid in laser cutting, the overall composition was difficult to spread on the wafer surface, and the coating process was difficult, and in particular, the coating requirements of the chips of the concave-convex structure could not be satisfied.

From the test results of example 1 and comparative examples 3 to 5, it is known that in comparative example 3, since benzyl alcohol does not contain an unsaturated bond, it is difficult to copolymerize the two, resulting in the absence of a water-soluble resin in the composition; while the parts of the water-soluble resin in comparative examples 4 and 5 are too much or too little in the overall composition, too much results in a composition having a much higher viscosity than that of example 1 and a lower adhesion, too little results in a composition having a lower solids content and adhesion, making the resulting composition difficult to use as a laser cutting protective material.

As can be seen from the comparison between example 1 and comparative example 6, when the leveling agent is polymethyl acrylate, the adhesion level of the composition of comparative example 6 is lower because the compatibility between polymethyl acrylate and the water-soluble resin is inferior to that between the polymethyl acrylate and the silicone leveling agent, and the dispersion uniformity of the resin is not improved, so that the composition can form a uniform protective film on the surface of the substrate only by the synergistic interaction between the leveling agent and a large amount of hydrophilic groups in the water-soluble resin.

As is evident from the comparison of the results of example 1 and comparative examples 7 to 10, the compositions of comparative examples 7 to 10 lack the leveling agent, the ultraviolet absorber, the corrosion inhibitor and the plasticizer defined in the components of the present application, respectively, and therefore the compositions of comparative examples 7 to 10 have low solids content, high viscosity and low adhesive force rating, and therefore the components of the present application are indispensable, and the compositions have the characteristics of high solids content, low viscosity and high adhesive force at the same time by mutual cooperation and synergy of the components.

With further reference to fig. 1-4, with the composition of example 1, fig. 1 can see that the wafer after coating is smooth, mirror-like, uniform and transparent; fig. 2 can be seen that a protective film is formed over the wafer bumps; FIG. 3 shows the relief of the protective film as it follows the wafer structure; however, with the composition of comparative example 1, it can be seen in FIG. 4 that the composition of comparative example 1 does not completely protect the bumps and is only tacky at some point.

As can be seen from the IR spectrum of the composition of example 1 of FIG. 5, 3340cm ^-1 Stretching vibration of hydroxyl at 2930cm ^-1 Stretching vibration of methyl at 1665cm ^-1 The stretching vibration of carbonyl corresponds to stretching vibration of amide I, and 1608cm ^-1 The characteristic peak of the amide II is shown. The water-soluble resin is polymerized by hydroxyethyl methacrylate and acrylamide.

Referring to fig. 6 to 8, wherein fig. 6 shows that the composition of example 1 has excellent adhesion as a laser cutting protective material, and no falling-off phenomenon is found by the test of the bayesian method; as can be seen from fig. 7 and 8, the compositions of comparative examples 1 and 2 were peeled off as a laser cutting protective material.

In conclusion, the composition has the characteristics of high solid content, low viscosity and high adhesive force, can be used as a laser cutting protection material, and has very good application prospect and large-scale industrialized popularization potential in the field of semiconductor cutting protection.

The composition, the preparation method and the application thereof in the laser cutting of the wafer provided by the embodiment of the application are described in detail, and specific examples are applied in the application to illustrate the principle and the implementation of the application, and the description of the above examples is only used for helping to understand the technical scheme and the core idea of the application; those of ordinary skill in the art will appreciate that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A composition as a laser dicing protective material in laser dicing of a wafer, characterized by comprising, in parts by mass:

the water-soluble resin is prepared by copolymerizing a first monomer and a second monomer, wherein the first monomer is selected from compounds with side groups containing the amide groups, the second monomer is selected from compounds with side groups containing the hydroxyl groups, and the mass ratio of the first monomer to the second monomer is 25 (5-10);

the leveling agent is at least one selected from polyether modified organic silicon, polyester modified organic silicon and end group modified organic silicon;

the first monomer is selected from acrylamide, and the second monomer is selected from at least one of hydroxyethyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxybutyl acrylate;

the molecular weight of the water-soluble resin is 50000-80000.

2. The composition of claim 1, wherein the composition comprises:

3. The composition of claim 1, wherein the ultraviolet absorber is selected from at least one of ferulic acid, 2-hydroxy-4-n-octoxybenzophenone, 2, 4-dihydroxybenzophenone, 2-hydroxy-4-diethylamino-2-carboxybenzophenone.

4. The composition according to claim 1, wherein the corrosion inhibitor is selected from at least one of cyclohexylamine, sodium silicate, sodium benzoate.

5. The composition according to claim 1, wherein the plasticizer is at least one selected from the group consisting of glycerol, 1, 3-butanediol, polyethylene glycol.

6. A process for the preparation of a composition as claimed in any one of claims 1 to 5, comprising: respectively weighing water-soluble resin, flatting agent, ultraviolet absorbent, corrosion inhibitor, plasticizer, organic solvent and deionized water in parts by weight, mixing and stirring to prepare a composition; wherein the stirring speed is 200-500 rpm; the stirring time is 1-5 h.

7. Use of a composition according to any one of claims 1 to 5 as a laser cut protection material in laser cutting of wafers.