Semiconductor process protection film and preparation method thereof

Abstract

The invention discloses a semiconductor process protective film and a preparation method thereof, and relates to the technical field of thin films, the preparation method comprises the following steps: dissolving dopamine hydrochloride, adjusting pH, adding a carbon material for reaction, filtering, washing and vacuum drying to obtain a functional filler; polyacrylic acid is added into water, a coupling agent and dopamine hydrochloride are added for a reaction, dialysis purification and freeze drying are performed, and functional PAA is obtained; the preparation method comprises the following steps: dissolving functionalized PAA in an organic solvent to prepare a glue solution, dispersing a functional filler in the organic solvent to prepare a functional filler suspension, filtering the functional filler suspension, and adding the filtered functional filler suspension into the glue solution to obtain a pressure-sensitive glue solution; and coating a base film with the pressure-sensitive adhesive solution, and performing drying and crosslinking to obtain the semiconductor process protection film. The invention discloses the semiconductor process protection film prepared by the method. The protective film can effectively block light rays from passing through, greatly reduces the light transmittance, and solves the problem that an existing protective film cannot be effectively recognized by a machine due to high light transmittance.

Description

Technical Field

[0001] The present invention relates to the technical field of thin films, and in particular to a semiconductor process protection film and a preparation method thereof. Background Art

[0002] With the rapid development of the electronics industry and the continuous upgrading of consumer electronic products, the production process is also constantly developing in the direction of rapidity, diversification and multi-function. Various new technologies and processes are constantly being developed, and the degree of production automation and precision are further improved. New requirements are constantly being put forward for the process protection film that plays a protective role in the related processing process.

[0003] Chip manufacturing is a highly precise and complex process. Wafer movement is a necessary step in the chip manufacturing process. In order to prevent foreign matter from contaminating the wafer during this process, a protective film with a viscosity of 100-200gf / 25mm is pasted on the surface of the wafer to ensure the normal progress of subsequent processes. Under the new manufacturing process standards, the traditional transparent protective film cannot be automatically removed because it cannot be identified, which seriously affects the processing and manufacturing of chips.

[0004] The new process requires that the protective film use opaque materials with stable adhesion, so that the chip manufacturing equipment can effectively identify the protective film, so that the film tearing machine can achieve accurate film tearing and ensure the integrity and smoothness of the chip processing process. In this context, it is urgent to develop a protective film material that is suitable for the new chip manufacturing process. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a semiconductor process protective film and a preparation method thereof, which can effectively block the passage of light, greatly reduce the light transmittance, and solve the problem that the existing protective film cannot be effectively recognized by the machine due to its high light transmittance.

[0006] The technical solution of the present invention to solve the above technical problem is as follows: a method for preparing a semiconductor process protective film is provided, comprising the following steps:

[0007] (1) dissolving dopamine hydrochloride in a Tris buffer at room temperature, adjusting the pH value to 7-9, then adding the carbon material and stirring and mixing, reacting at a temperature of 40-60° C. for 2-6 hours, the suspension changes from brown to black, and then filtering, washing and vacuum drying in sequence to obtain a functional filler;

[0008] (2) adding polyacrylic acid to distilled water, then adding a coupling agent and dopamine hydrochloride, stirring and reacting at room temperature, adjusting the pH to 5-6 during the reaction, dialyzing in sodium chloride solution and distilled water in turn after the reaction is completed, and finally freeze-drying to obtain functionalized PAA;

[0009] (3) taking the functionalized PAA obtained in step (2), the organic solvent, the functional filler obtained in step (1) and the curing agent in a mass ratio of 100:100-150:5-25:0.5-2, dissolving the functionalized PAA in part of the organic solvent to obtain an adhesive solution, dispersing the functional filler in the remaining organic solvent to obtain a functional filler suspension, filtering the functional filler suspension and adding it to the adhesive solution, then adding the curing agent, stirring and mixing evenly, to obtain a pressure-sensitive adhesive solution;

[0010] (4) coating the pressure-sensitive adhesive obtained in step (3) on the base film, drying at 90-120° C. for 1-5 min, and then cross-linking at 140-165° C. for 3-7 min under vacuum conditions to obtain a semiconductor process protective film.

[0011] Furthermore, in step (1), the carbon material is one of lamellar graphite and porous carbon.

[0012] The thickness of flake graphite is less than 15nm, the diameter of flake is 3-6μm, and the specific surface area is >2cm 2 / g; porous carbon particle size is 1-3μm, pore size is 10-100nm, pore volume>1cm 3 / g. It may also be other carbon materials with a lamellar structure and a pore structure.

[0013] Furthermore, in step (1), dopamine hydrochloride can also be replaced by other polyphenols and indoles with amino groups and light-absorbing polymerizable small molecule monomers.

[0014] Furthermore, in step (1), the mass ratio of dopamine hydrochloride to carbon material is 1:1-3.

[0015] Furthermore, in step (1), vacuum drying is performed at 70° C. for 6-8 h.

[0016] Furthermore, in step (2), the coupling agent is one of N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC), N-hydroxysuccinimide (NHS) and 1-hydroxybenzotriazole (HOBT).

[0017] Furthermore, in step (2), the mass ratio of polyacrylic acid, coupling agent, dopamine hydrochloride and water is 3-8:2:0.5-1:50-100.

[0018] Furthermore, in step (2), the product is first purified in a sodium chloride solution for 40-50 hours and then dialyzed in distilled water for 5-7 hours.

[0019] Furthermore, in step (3), the organic solvent is at least one of acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, toluene, xylene and carbon tetrachloride. The organic solvent may be one or more of ketones, esters, aromatics and aliphatics.

[0020] Furthermore, in step (3), the curing agent is a diisocyanate or polyisocyanate small molecule having an isocyanate end group.

[0021] Furthermore, in step (3), the functionalized PAA is dissolved in the organic solvent by stirring at a speed of 2000-2500 r / min for 90-120 min; and the functional filler is dispersed in the organic solvent by stirring at a speed of 2000-2500 r / min for 10-20 min.

[0022] Further, in step (3), filtering is performed using 400-500 mesh gauze.

[0023] Furthermore, in step (4), the base film is a black PET film; the thickness of the base film is 10-15 μm.

[0024] Furthermore, in step (4), the pressure-sensitive adhesive is coated to a thickness of 1-3 μm.

[0025] The invention also discloses a semiconductor process protection film prepared by a method for preparing the semiconductor process protection film.

[0026] The present invention has the following beneficial effects:

[0027] 1. The method of the present invention utilizes dopamine to functionally modify PAA, so that it has a certain light absorption capacity and changes its refractive index, so that a difference is generated between the refractive indexes of the film and the adhesive layer. When light passes through the film and enters the adhesive layer, a large-angle refraction or reflection occurs at the interface between the two phases, thereby reducing the amount of light entering the adhesive layer. When dopamine side chains are introduced into PAA, it is beneficial to improve the compatibility and stability of the entire system.

[0028] 2. The carbon material added in the method of the present invention has a lamellar and porous structure, which can block the passage of light. The porous structure of the carbon material itself and the interface between the carbon material and the carbon material can form enough refractive surfaces, which can effectively slow down the time for light to pass through the adhesive layer. When the light is refracted and reflected in the adhesive layer, part of the light energy will be consumed.

[0029] 3. The method of the present invention grows polydopamine on the surface of the carbon material, and then combines the gaps and interfaces of the carbon material to convert the light reflected and refracted in the adhesive layer into heat energy for dissipation, thereby improving the light absorption capacity. The generated heat energy can be evenly conducted to the surface of the protective film through the carbon material.

[0030] 4. In the method of the present invention, the adhesive layer is first cross-linked with the curing agent small molecule and PAA at 90-120°C, and then the amino group of polydopamine and the carboxyl group in PAA are cross-linked by reaction at 140-165°C in a vacuum environment. A hybrid interpenetrating cross-linked network is formed by the two cross-linking methods, which greatly improves the cohesive force of the adhesive layer, avoids damage to the adhesive layer, and prevents the migration of components in the adhesive layer.

[0031] 5. The catechol structure in dopamine has unique adhesion properties, which can improve the wettability and adhesion of the entire adhesive layer to a certain extent. DETAILED DESCRIPTION

[0032] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific conditions are specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0033] Example 1

[0034] A semiconductor process protection film, the preparation method of which comprises the following steps:

[0035] (1) Dopamine hydrochloride is dissolved in Tris buffer at room temperature, the pH value is adjusted to 8, and then porous carbon is added and stirred and mixed, and reacted at 60°C for 2 hours. The suspension changes from brown to black, and is filtered and washed with deionized water, and then vacuum dried at 70°C for 6 hours to obtain a functional filler; wherein the mass ratio of dopamine hydrochloride to porous carbon is 1:2;

[0036] (2) adding polyacrylic acid to distilled water, then adding N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC) and dopamine hydrochloride, stirring and reacting at room temperature for 12 hours, adjusting the pH to 5.5 during the reaction, purifying in sodium chloride solution for 48 hours after the reaction, then dialyzing in distilled water for 6 hours, and finally freeze-drying to obtain functionalized PAA; wherein the mass ratio of polyacrylic acid, EDC, dopamine hydrochloride and water is 4:2:1:50;

[0037] (3) taking the functionalized PAA obtained in step (2), the organic solvent (ethyl acetate), the functional filler obtained in step (1) and the isocyanate curing agent in a mass ratio of 100:120:15:1.2, dissolving the functionalized PAA in part of the organic solvent by stirring at a speed of 2500 r / min for 90 min to obtain a glue solution, dispersing the functional filler in the remaining organic solvent by stirring at a speed of 2000 r / min for 10 min to obtain a functional filler suspension, filtering the functional filler suspension through a 400-mesh gauze and adding it to the glue solution, adding the curing agent, stirring at a speed of 1000 r / min during the process, and then stirring and mixing at a speed of 2500 r / min for 20 min to obtain a pressure-sensitive adhesive solution;

[0038] (4) The pressure-sensitive adhesive obtained in step (3) is coated on a black PET film with a thickness of 10 μm to a thickness of 2 μm, dried at 100° C. for 3 min, and then cross-linked at 160° C. for 5 min under vacuum conditions to obtain a semiconductor process protective film.

[0039] Example 2

[0040] A semiconductor process protection film, which is different from Example 1 in that the porous carbon of the carbon material in the preparation method is replaced by lamellar graphite.

[0041] Example 3

[0042] A semiconductor process protection film, the preparation method of which comprises the following steps:

[0043] (1) Dopamine hydrochloride is dissolved in Tris buffer at room temperature, the pH value is adjusted to 7, and then flake graphite is added and stirred and mixed, and the mixture is reacted at 50°C for 6 hours, and the suspension changes from brown to black. The suspension is filtered and washed with deionized water, and then vacuum dried at 70°C for 8 hours to obtain a functional filler; wherein the mass ratio of dopamine hydrochloride to flake graphite is 1:1;

[0044] (2) adding polyacrylic acid to distilled water, then adding N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC) and dopamine hydrochloride, stirring and reacting at room temperature for 12 hours, adjusting the pH to 5 during the reaction, purifying in sodium chloride solution for 48 hours after the reaction, then dialyzing in distilled water for 6 hours, and finally freeze-drying to obtain functionalized PAA; wherein the mass ratio of polyacrylic acid, EDC, dopamine hydrochloride and water is 3:2:0.5:50;

[0045] (3) taking the functionalized PAA obtained in step (2), the organic solvent (acetone), the functional filler obtained in step (1) and the curing agent in a mass ratio of 100:100:5:0.5, dissolving the functionalized PAA in part of the organic solvent by stirring at a speed of 2000 r / min for 120 min to obtain a glue solution, dispersing the functional filler in the remaining organic solvent by stirring at a speed of 2500 r / min for 20 min to obtain a functional filler suspension, filtering the functional filler suspension through 500 mesh gauze and adding it to the glue solution, then adding the curing agent, stirring and mixing evenly to obtain a pressure-sensitive adhesive solution;

[0046] (4) The pressure-sensitive adhesive obtained in step (3) is coated on a black PET film with a thickness of 15 μm to a thickness of 1 μm, dried at 90° C. for 5 min, and then cross-linked at 165° C. for 3 min under vacuum conditions to obtain a semiconductor process protective film.

[0047] Example 4

[0048] A semiconductor process protection film, the preparation method of which comprises the following steps:

[0049] (1) Dopamine hydrochloride is dissolved in Tris buffer at room temperature, the pH value is adjusted to 9, and then porous carbon is added and stirred and mixed, and the mixture is reacted at 50°C for 4 hours, and the suspension changes from brown to black. The suspension is filtered and washed with deionized water, and then vacuum dried at 70°C for 7 hours to obtain a functional filler; wherein the mass ratio of dopamine hydrochloride to flake graphite to porous carbon is 1:3;

[0050] (2) adding polyacrylic acid to distilled water, then adding N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC) and dopamine hydrochloride, stirring and reacting at room temperature for 12 hours, adjusting the pH to 6 during the reaction, purifying in a sodium chloride solution for 48 hours after the reaction, then dialyzing in distilled water for 6 hours, and finally freeze-drying to obtain functionalized PAA; wherein the mass ratio of polyacrylic acid, EDC, dopamine hydrochloride and water is 8:2:1:100;

[0051] (3) taking the functionalized PAA obtained in step (2), the organic solvent (xylene), the functional filler obtained in step (1) and the curing agent in a mass ratio of 100:150:25:2, dissolving the functionalized PAA in part of the organic solvent by stirring at a speed of 2200 r / min for 100 min to obtain a glue solution, dispersing the functional filler in the remaining organic solvent by stirring at a speed of 2300 r / min for 15 min to obtain a functional filler suspension, filtering the functional filler suspension through a 450-mesh gauze and adding it to the glue solution, then adding the curing agent, stirring and mixing evenly, to obtain a pressure-sensitive adhesive solution;

[0052] (4) The pressure-sensitive adhesive obtained in step (3) is coated on a black PET film with a thickness of 12 μm to a thickness of 3 μm, dried at 120° C. for 1 min, and then cross-linked at 140° C. for 7 min under vacuum conditions to obtain a semiconductor process protective film.

[0053] Comparative Example 1

[0054] A protective film, which is different from Example 1 in that no carbon material is added in the preparation step (1).

[0055] Comparative Example 2

[0056] A protective film, which is different from embodiment 1 in that it is a semiconductor process protective film, and its preparation method includes the following steps:

[0057] (1) PAA, organic solvent, carbon material and curing agent are taken in a mass ratio of 100:120:15:1.2, PAA is dissolved in part of the organic solvent by stirring at a speed of 2500 r / min for 90 minutes to obtain an adhesive solution, the carbon material is dispersed in the remaining organic solvent by stirring at a speed of 2000 r / min for 10 minutes to obtain a suspension, the suspension is filtered through a 400-mesh gauze and added to the adhesive solution, the curing agent is added, the mixture is stirred at a speed of 1000 r / min during the process, and then stirred and mixed at a speed of 2500 r / min for 20 minutes to obtain a pressure-sensitive adhesive solution;

[0058] (2) The pressure-sensitive adhesive obtained in step (1) is coated on a black PET film with a thickness of 10 μm to a thickness of 2 μm, dried at 100° C. for 3 min, and then cross-linked at 160° C. for 5 min under vacuum conditions to obtain a protective film.

[0059] Test Example 1

[0060] The performance tests were performed on the protective films prepared in Examples 1-2 and Comparative Examples 1-2, and the results are shown in Table 1.

[0061] Table 1 Performance test results

[0062] sample Glue layer thickness Viscosity (gf / 25mm) Lab value (L*) Light transmittance Example 1 2μm 123 18.63 0.1 Example 2 2μm 129 17.70 0.1 Comparative Example 1 2μm 177 41.25 31.1 Comparative Example 2 2μm 143 26.77 15.4

[0063] It can be seen from Table 1 that the carbon material added in the method of the present invention can effectively block the passage of light, and the functional modification using dopamine can further increase the light absorption capacity and significantly reduce the light transmittance of the protective film.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a semiconductor process protective film, characterized in that: The following steps are involved: (1) dissolving dopamine hydrochloride in a Tris buffer at room temperature, adjusting the pH value to 7-9, then adding the carbon material and stirring and mixing, reacting at a temperature of 40-60° C. for 2-6 hours, the suspension changes from brown to black, and then filtering, washing and vacuum drying in sequence to obtain a functional filler; (2) adding polyacrylic acid to distilled water, then adding a coupling agent and dopamine hydrochloride, stirring and reacting at room temperature, adjusting the pH to 5-6 during the reaction, dialyzing in sodium chloride solution and distilled water in turn after the reaction is completed, and finally freeze-drying to obtain functionalized PAA; (3) taking the functionalized PAA obtained in step (2), an organic solvent, the functional filler obtained in step (1) and a curing agent in a mass ratio of 100:100-150:5-25:0.5-2, dissolving the functionalized PAA in part of the organic solvent to obtain an adhesive solution, dispersing the functional filler in the remaining organic solvent to obtain a functional filler suspension, filtering the functional filler suspension and adding it to the adhesive solution, then adding the curing agent, stirring and mixing, and obtaining a pressure-sensitive adhesive solution; (4) coating the pressure-sensitive adhesive obtained in step (3) on the base film, drying at 90-120° C. for 1-5 min, and then cross-linking at 140-165° C. for 3-7 min under vacuum conditions to obtain a semiconductor process protective film.

2. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (1), the carbon material is one of lamellar graphite and porous carbon.

3. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (1), the mass ratio of the dopamine hydrochloride to the carbon material is 1:1-3.

4. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (2), the coupling agent is one of N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride, N-hydroxysuccinimide and 1-hydroxybenzotriazole.

5. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (2), the mass ratio of the polyacrylic acid, coupling agent, dopamine hydrochloride and water is 3-8:2:0.5-1:50-100.

6. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (2), the product is first purified in a sodium chloride solution for 40-50 hours and then dialyzed in distilled water for 5-7 hours.

7. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (3), filter using 400-500 mesh gauze.

8. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (4), the base film is a black PET film; the thickness of the base film is 10-15 μm.

9. The method for preparing a semiconductor process protection film according to claim 1, wherein: In step (4), the pressure-sensitive adhesive is coated to a thickness of 1-3 μm.

10. A semiconductor process protection film obtained by the method for preparing a semiconductor process protection film according to any one of claims 1 to 9.