Solvent-free UV curing single-layer structure wafer grinding protective film suitable for large solder ball diameter wafer and preparation method of solvent-free UV curing single-layer structure wafer grinding protective film

Abstract

The invention discloses a solvent-free UV curing single-layer structure wafer grinding protective film suitable for a large solder ball diameter wafer and a large solder ball diameter wafer, and relates to the technical field of special effect film structure preparation, and the protective film comprises an elastic main body polymer, a plasticizer, a light curing agent, a nano filler, an adhesion promoter, a leveling agent and a defoaming agent. The protective film provided by the invention has large elasticity and high adsorption capacity, the film has a single-layer structure and does not comprise an adhesive layer, and a series of problems caused by an adhesive layer of a traditional structure are avoided through vacuum adsorption of the wafer protective film of the base material.

Description

Technical Field

[0001] The invention provides a solvent-free UV-curable single-layer wafer grinding protective film suitable for large-size tin ball wafers and large-size solder ball wafers, and relates to the technical field of special-effect film structure preparation. Background Art

[0002] With the rapid development of science and technology, the semiconductor industry is the core of today's electronic information industry, and every link in its manufacturing process is crucial. Wafer grinding is a key link in semiconductor production, and the emergence of UV curing wafer grinding protective film technology has brought revolutionary changes to this link.

[0003] UV curing technology, also known as ultraviolet light curing technology, is a technology that uses ultraviolet light to trigger chemical reactions and quickly solidify liquid materials. This technology was originally mainly used in the printing and coating industries and is widely praised for its high efficiency and environmental protection. In recent years, UV curing technology has gradually penetrated into the field of semiconductor manufacturing, especially in the wafer grinding process, the application of UV curing wafer grinding protective film is particularly important.

[0004] The main function of the protective film during wafer grinding is to protect the wafer surface from contamination by impurities, dust, etc. during grinding, and to prevent the wafer from being damaged during grinding. Although traditional protective films can play a certain protective role, they often cause secondary contamination or damage to the wafer when removed. The emergence of UV-curable wafer grinding protective films effectively solves this problem.

[0005] When the particle size of the solder ball on the wafer surface is larger, it means that the wafer surface has higher undulations and unevenness. Therefore, the protective film needs to have stronger adhesion to ensure that it can fit closely to the wafer surface during the grinding process to prevent the grinding fluid and debris from penetrating into the gap between the solder ball and the wafer. Large solder balls may produce greater stress concentration during the grinding process, so the protective film needs to have better stress relaxation and elongation. This can effectively avoid wafer breakage or ripples due to excessive stress during the grinding process. Since the particle size of large solder balls increases the difficulty and time of grinding, the protective film needs to have higher wear resistance to ensure that its protective performance can be maintained during the long grinding process. Although strong adhesion is required to fix the wafer, after the grinding is completed, the protective film should be able to be easily and cleanly peeled off from the wafer surface without leaving any residue or causing damage to the wafer surface.

[0006] Currently, most of the UV-curable wafer grinding protective films on the market are designed for standard-sized wafers and small solder ball particle sizes. For wafers with large solder ball particle sizes, these protective films may not provide sufficient protection and adaptability. Due to the increased unevenness of the wafer surface caused by the large solder ball particle size, it may make it more difficult to peel off the protective film, and may even cause damage to the wafer surface. Faced with the longer time and higher intensity grinding requirements brought by the large solder ball particle size, the wear resistance of the existing protective film may not be met, resulting in a decrease in the protection effect. In response to the special needs of large solder ball particle size wafers and large solder ball wafers, customized protective film solutions may be required, which will undoubtedly increase R&D and production costs. Although UV-curable wafer grinding protective films play an important role in semiconductor manufacturing, there are still many challenges and problems that need to be solved in the application of wafers with large solder ball particle sizes. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers. The specific scheme is as follows: A solvent-free UV curing single-layer wafer grinding protective film suitable for large tin ball particle size wafers and large solder ball particle size wafers comprises an elastic main polymer, a plasticizer, a light curing agent, a nano filler, an adhesion promoter, a leveling agent and a defoaming agent.

[0008] Preferably, the solder balls include one or more of tin balls, copper balls, and gold balls.

[0009] Preferably, the components in the solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers are calculated by mass as follows: Elastic main polymer: 60-75 parts, Plasticizer: 10-20 parts, Light curing agent: 3-8 parts, Nano filler: 5-10 parts, Adhesion promoter: 1-3 parts, Leveling agent: 0.5-2 parts, Defoaming agent: 0.5-1 part.

[0010] Preferably, the elastic main polymer includes one or both of polyurethane acrylate (PUA) and silicone acrylate (Silicone Acrylate) copolymers.

[0011] Preferably, the plasticizer includes one or more of polydimethylsiloxane plasticizer and silicone oil plasticizer.

[0012] Preferably, the photocuring agent includes one or two of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0013] Preferably, the nanofiller comprises one or both of silicon dioxide and nanoclay.

[0014] Preferably, the adhesion promoter includes one or more of titanate AP100, Adherant ADP promoter or BYK-4510 adhesion promoter.

[0015] Preferably, the leveling agent includes one or two of a polyacrylate leveling agent and an acrylic leveling aid.

[0016] Preferably, the defoaming agent includes one or more of a polydimethylsiloxane defoaming agent, an organosilicon defoaming aid, and a silicone oil defoaming agent.

[0017] Preferably, the method for preparing the solvent-free UV-curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers comprises: S1. Mix and stir the components in the formula evenly; S2. The obtained material is evenly coated on the surface of the release film; S3, pre-curing; S4, UV curing; S5. Remove the release film to obtain a protective film that can be used directly.

[0018] Preferably, the coating comprises spin coating, dip coating or spray coating.

[0019] Preferably, the spin coating has a rotation speed range of 1000-5000 rpm and a time of 30-120 seconds; the dip coating has a dip speed of 1-10 mm / s and an adjustable pulling speed; the spray coating has a spray pressure of 0.2-0.6 MPa and a spray distance of 15-30 cm.

[0020] Preferably, the pre-curing temperature ranges from 50 to 80° C. and the time ranges from 10 to 20 minutes.

[0021] Preferably, for the UV curing, the UV light source power is 200-1000 W and the curing time is 20-60 seconds.

[0022] Preferably, the thickness of the obtained protective film is controlled to be 5-50 μm.

[0023] The beneficial effects of the present invention are as follows: The present invention provides a solvent-free UV-curable single-layer wafer grinding protective film suitable for large tin ball particle size wafers and large solder ball particle size wafers. The film has high elasticity and high adsorption force. The film has a single-layer structure and does not include an adhesive layer. The wafer protective film is adsorbed on the substrate by vacuum, avoiding a series of problems caused by the traditional structure adhesive layer. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0025] Unless otherwise defined, all professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein may be applied to the present invention. The preferred implementation methods and materials described herein are for demonstration purposes only and are not intended to limit the content of this application.

[0026] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are purchased from commercial channels unless otherwise specified. Reagents used in the examples: polyurethane acrylate (PUA) Ebecryl 230, leveling agent PERENOL F41, defoamer BYK 022, nano-silica Evonik, polysiloxane plasticizer BYK 307, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) Hubei Chengfeng Chemical Co., Ltd., titanate AP100 Zhuhai Weiken Chemical Co., Ltd.

[0027] Example 1 Solvent-free UV-curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers formula: Elastic main polymer: 75 parts, Plasticizer: 10 parts, Light curing agent: 3 parts, Nano filler: 5 parts, Adhesion promoter: 1 part, Leveling agent: 0.5 parts, Defoaming agent: 0.5 parts.

[0028] Preparation method: S1. Mix and stir the components in the formula evenly; S2. The obtained material is evenly coated on the surface of the release film; S3, pre-curing; S4, UV curing; S5. Remove the release film to obtain a protective film that can be used directly.

[0029] The coating includes spraying with a spraying pressure of 0.2 MPa and a spraying distance of 15 cm.

[0030] The pre-curing temperature range is 50°C and the time is 20 minutes.

[0031] UV curing: UV light source power is 200 W, and curing time is 60 seconds.

[0032] The thickness of the obtained protective film was controlled at 20 μm.

[0033] Example 2 Solvent-free UV-curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers formula: Elastic main polymer: 60 parts, Plasticizer: 20 parts, Light curing agent: 8 parts, Nano filler: 10 parts, Adhesion promoter: 3 parts, Leveling agent: 2 parts, Defoaming agent: 1 part.

[0034] Preparation method: S1. Mix and stir the components in the formula evenly; S2. The obtained material is evenly coated on the surface of the release film; S3, pre-curing; S4, UV curing; S5. Remove the release film to obtain a protective film that can be used directly.

[0035] The coating includes spraying with a spraying pressure of 0.2 MPa and a spraying distance of 15 cm.

[0036] The pre-curing temperature range is 50°C and the time is 20 minutes.

[0037] UV curing: UV light source power is 200 W, and curing time is 60 seconds.

[0038] The thickness of the obtained protective film was controlled at 20 μm.

[0039] Example 3 Solvent-free UV-curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers formula: Elastic main polymer: 60 parts, Plasticizer: 10 parts, Light curing agent: 3 parts, Nano filler: 5 parts, Adhesion promoter: 1 part, Leveling agent: 0.5 parts, Defoaming agent: 0.5 parts.

[0040] Preparation method: S1. Mix and stir the components in the formula evenly; S2. The obtained material is evenly coated on the surface of the release film; S3, pre-curing; S4, UV curing; S5. Remove the release film to obtain a protective film that can be used directly.

[0041] The coating includes spraying with a spraying pressure of 0.2 MPa and a spraying distance of 15 cm.

[0042] The pre-curing temperature range is 50°C and the time is 20 minutes.

[0043] UV curing: UV light source power is 200 W, and curing time is 60 seconds.

[0044] The thickness of the obtained protective film was controlled at 20 μm.

[0045] Example 4 Solvent-free UV-curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers formula: Elastic main polymer: 60 parts, Plasticizer: 10 parts, Light curing agent: 3 parts, Nano filler: 5 parts, Adhesion promoter: 1 part, Leveling agent: 0.5 parts, Defoaming agent: 0.5 parts.

[0046] Preparation method: S1. Mix and stir the components in the formula evenly; S2. The obtained material is evenly coated on the surface of the release film; S3, pre-curing; S4, UV curing; S5. Remove the release film to obtain a protective film that can be used directly.

[0047] The coating includes spraying, with a spraying pressure of 0.6 MPa and a spraying distance of 30 cm.

[0048] The pre-curing temperature range is 80°C and the time is 10 minutes.

[0049] UV curing: UV light source power is 1000 W, and curing time is 20 seconds.

[0050] The thickness of the obtained protective film was controlled at 20 μm.

[0051] The release film of the product obtained in the above embodiment is removed before use.

[0052] Performance testing: The wafer solder balls used for testing are tin balls with a particle size of 200μm. Check the uniformity and integrity of the protective film. Clean the wafer surface to ensure that it is free of dust, oil, moisture and other contaminants. Remove the sample release film, evenly stick the sample on the wafer surface, and test the adhesion. After heat treatment at 80°C for 30 minutes, remove the protective film and observe the remaining glue. The comparative example is a commercially available multi-layer wafer protective film (3M™ Wafer Support System (WSS)). The results are shown in Table 1. The adhesion can be reflected by the stretching method by measuring the force required to separate the protective film from the substrate during the stretching process (since the film provided by the present invention is electrostatically adsorbed, it is not fully applicable to the standard GB / T 2792-2014 "Test method for peel strength of adhesive tape") Table 1 Sample performance test results sample Separation tensile force / peel strength N / m Whether to leave glue Example 1 58.7 no Example 2 56.5 no Example 3 60.8 no Example 4 61.2 no Comparative Example 34.1 yes It can be seen from the test results that applying the single-layer structural protective film provided by the present invention on the surface of a wafer with a large solder ball particle size can greatly improve the peeling strength, and achieve the purpose of the present invention to avoid the problem of glue retention in traditional structural protective films, and the resulting film product is uniform and complete, and the adsorption force meets the use requirements.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0054] The present invention and its implementation methods are described above, and such description is not restrictive. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A solvent-free UV curable single-layer wafer grinding protective film suitable for large-size solder ball wafers and large-size solder ball wafers, characterized in that: It includes elastic main polymer, plasticizer, photocuring agent, nano filler, adhesion promoter, leveling agent and defoaming agent.

2. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The components in the protective film are calculated by mass: Elastic main polymer: 60-75 parts, plasticizer: 10-20 parts, light curing agent: 3-8 parts, nano filler: 5-10 parts, adhesion promoter: 1-3 parts, leveling agent: 0.5-2 parts, defoaming agent: 0.5-1 part.

3. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The elastic main polymer includes one or both of polyurethane acrylate (PUA) and silicone acrylate (Silicone Acrylate) copolymers.

4. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The plasticizer includes one or more of polydimethylsiloxane plasticizer and silicone oil plasticizer.

5. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The photocuring agent includes one or two of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO) and 2-hydroxy-2-methyl-1-phenyl-1-propanone.

6. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The nano filler includes one or both of silicon dioxide and nano clay.

7. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The adhesion promoter includes one or more of titanate AP100, Adherant ADP promoter or BYK-4510 adhesion promoter.

8. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The leveling agent includes one or two of a polyacrylate leveling agent and an acrylic acid leveling aid.

9. The solvent-free UV curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to claim 1, characterized in that: The defoaming agent includes one or more of a polydimethylsiloxane defoaming agent, an organic silicon defoaming aid, and a silicone oil defoaming agent.

10. A method for preparing a solvent-free UV-curable single-layer wafer grinding protective film suitable for large solder ball particle size wafers and large solder ball particle size wafers according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Mix and stir the components in the formula evenly; S2. The obtained material is evenly coated on the surface of the release film; S3, pre-curing; S4, UV curing; S5. Remove the release film to obtain a protective film that can be used directly.