Photocuring adhesive for packaging glass substrate as well as preparation method and application of photocuring adhesive

Abstract

The invention belongs to the technical field of photocuring materials, and particularly relates to a photocuring adhesive for packaging a glass substrate and a preparation method and application of the photocuring adhesive for packaging the glass substrate, and the photocuring adhesive for packaging the glass substrate comprises the following components in percentage by weight: 20-40% of organic silicon modified alicyclic epoxy resin; 5%-20% of fluorine modified epoxy resin; 25%-45% of a flexible acrylate monomer; 20%-40% of organic silicon modified acrylate; 5%-10% of an adhesion promoter; 0.3%-3% of a free radical photoinitiator; and 0.1%-2% of a cationic photoinitiator. According to the invention, the organic silicon modified alicyclic epoxy resin is added and matched with other components, and the weight ratio of the components is regulated, so that the light curing adhesive for packaging the glass substrate has excellent toughness and elongation, the adhesive force is improved, the applicable light source wavelength range is wide, and the processing efficiency of the packaging adhesive is improved.

Description

Technical Field

[0001] The present invention relates to a photocurable adhesive for glass substrate encapsulation, its preparation method and application, and belongs to the technical field of photocurable materials. Background Art

[0002] Glass substrates currently play an important role in the fields of encapsulation and lithography technologies. One of its most attractive features is its low dielectric constant, which can minimize signal propagation delay and crosstalk between adjacent interconnects, which is crucial for high-speed electronic devices. It can also reduce the capacitance between interconnects, enabling faster signal transmission and improving overall performance. In applications where speed is crucial, such as data centers, telecommunications, and high-performance computing, using glass substrates can significantly improve system efficiency and data throughput. The low dielectric constant also enables better impedance control, ensuring signal integrity throughout the circuit, which is particularly attractive in RF applications as impedance matching is crucial for maximizing power transfer and minimizing signal loss. By providing consistent electrical properties across the substrate surface, glass substrates facilitate the design and manufacture of high-frequency circuits with higher reliability.

[0003] Another key advantage of glass substrates is their excellent thermal stability, which is crucial for maintaining device performance under fluctuating thermal conditions. Unlike copper-clad laminates that can deform or delaminate under thermal stress, glass substrates have very little dimensional change over a wide temperature range. In applications where thermal management is crucial, such as automotive electronics, aerospace systems, and industrial control, glass can withstand thermal cycling and maintain dimensional integrity under stress, helping to prevent electrical short circuits, open circuits, or other reliability issues typically associated with temperature-induced mechanical strain.

[0004] However, glass substrates also have their own limitations. A major challenge faced by glass substrate lithography technology is its inherent fragility, which has become particularly prominent as the industry moves towards using thinner substrates to meet higher device integration and performance requirements. Solving the fragility problem of glass requires the use of edge encapsulation adhesives for the substrate to reduce the risk of handling the fragile glass substrate. Conventional encapsulation technologies generally use thermal curing solutions, but they are inefficient, and the acid and alkali resistance and high temperature resistance of the encapsulation adhesives cannot meet the requirements, and the adhesion to the film materials attached to the glass substrate is low, resulting in reduced reliability of the glass substrate. Summary of the Invention

[0005] Aiming at the technical problems of the existing edge encapsulation adhesives for glass substrates using thermal curing process with low processing efficiency and the performance of the encapsulation adhesives not meeting the requirements, the present invention provides a photocurable adhesive for glass substrate encapsulation, its preparation method and application.

[0006] The technical solutions of the present invention to solve the above technical problems are as follows: One of the objectives of the present invention is to provide a photocurable adhesive for glass substrate encapsulation, which comprises the following components by weight percentage: Organosilicon-modified alicyclic epoxy resin: 20% - 40%; Fluorine-modified epoxy resin: 5% - 20%; Flexible acrylate monomer: 25% - 45%; Organosilicon-modified acrylate: 20% - 40%; Adhesion promoter: 5% - 10%; Free radical photoinitiator: 0.3% - 3%; Cationic photoinitiator: 0.1% - 2%.

[0007] The beneficial effect of the present invention lies in that: the present invention provides a cationic photocurable adhesive for glass substrate encapsulation. By adding organosilicon-modified alicyclic epoxy resin and cooperating with other components, and by regulating the weight ratio of each component, the photocurable adhesive for glass substrate encapsulation has excellent toughness and elongation, improves the adhesion, and has a wide range of applicable light source wavelengths, thus improving the processing efficiency of the encapsulating adhesive.

[0008] Based on the above technical solution, the present invention can also be improved as follows: Further, the organosilicon-modified alicyclic epoxy resin has the structure shown in formula (I):

[0009] (I), wherein, a ≥ 10, b ≥ 3, and both a and b are integers.

[0010] The beneficial effect of adopting the above further technical solution lies in that: the organosilicon-modified alicyclic epoxy resin adopted in the present invention is an organosilicon oligomer containing 3 or more alicyclic epoxy groups, and the alicyclic epoxy groups are on the side chain. By reasonably designing the chain segment structure of the organosilicon and the position and quantity of the epoxy functional groups, the organosilicon-modified alicyclic epoxy resin has excellent toughness and elongation, greatly improving the toughness and elongation of the photocurable adhesive.

[0011] Further, the preparation method of the organosilicon-modified alicyclic epoxy resin is as follows: Mix 1,2-epoxy-4-vinylcyclohexane and platinum catalyst evenly and heat, then dropwise add hydrogen-containing silicone oil on the side. During the dropping process, control the temperature below 60°C and the dropping rate to be completed within 60 minutes. After the dropping is completed, raise the temperature to 60°C - 90°C and react to obtain the organosilicon-modified alicyclic epoxy resin; The reaction formula involved in the above reaction is as follows: .

[0012] Furthermore, the fluorine-modified epoxy resin refers to the polymer of 2,2-bis(4-hydroxyphenyl)hexafluoropropane and (chloromethyl)oxirane.

[0013] Furthermore, the fluorine-modified epoxy resin has the structure shown in formula (II):

[0014] (II).

[0015] The beneficial effect of adopting the above further technical solution is that: the fluorine-modified epoxy resin is an epoxy resin containing fluorine elements in the molecular chain, and the C-F bond energy contained therein is high (about 485 kJ / mol), and it has extremely strong resistance to strong acids (such as concentrated sulfuric acid, aqua regia), strong bases, oxidants and organic solvents, and can further improve the acid and alkali resistance of the cured glue.

[0016] Furthermore, the organosilicon-modified acrylate is the product of the polymerization of bis-terminal monoalkylhydroxy organosilicon and isocyanate ethyl acrylate, and it has the structure shown in formula (III):

[0017] (III), wherein, n is an integer of ≥10.

[0018] The beneficial effect of adopting the above further technical solution is that: the organosilicon-modified acrylate synthesized by bis-terminal monoalkylhydroxy organosilicon and isocyanate ethyl acrylate has a lower viscosity, and the organosilicon chain segment on the molecular chain can greatly improve the toughness and elongation of the photocurable glue.

[0019] Furthermore, the preparation method of the organosilicon-modified acrylate is as follows: Mix bis-terminal monoalkylhydroxy organosilicon and isocyanate ethyl acrylate and heat, the reaction temperature is 70°C to 85°C, the reaction time is 2h to 4h, test NCO, and terminate the reaction after the NCO completely disappears to obtain the organosilicon-modified acrylate; The reaction formula involved in the above reaction is as follows: .

[0020] Furthermore, the flexible acrylate monomer refers to a multi-alkyl acrylate having a flexible chain segment. Preferably, the flexible acrylate monomer is selected from any one or two or more of dodecyl acrylate, tridecyl acrylate, octadecyl acrylate, dodecyl methacrylate, tridecyl methacrylate or octadecyl methacrylate.

[0021] Furthermore, the adhesion promoter is rosin phenol, which has the structure shown in formula (IV):

[0022] (IV); The radical photoinitiator is selected from any one or two or more of anthracene derivatives, benzoin derivatives, benzophenone and its derivatives, acetophenone and its derivatives, and methyl o-benzoylbenzoate; The cationic photoinitiator is selected from any one or two or more of aromatic diazonium salts, triarylsulfonium salts, diaryliodonium salts, and aromatic ferrocene salts. Preferably, the triarylsulfonium salt is a mixed-type triarylsulfonium hexafluoroantimonate salt, and the aromatic ferrocene salts are selected from IRGACURE 250, IRGACURE 261, IRGACURE 262, etc.

[0023] The beneficial effect of adopting the above further technical solution is that rosin phenol is a reaction product of rosin and phenol. The molecular structure of rosin phenol contains both carboxyl and hydroxyl groups. Among them, the hydroxyl group reacts with the alicyclic epoxy to incorporate rosin phenol into the macromolecule of the polymer, and the carboxyl group has good adhesion to glass and film materials such as ABF (Ajinomoto build-up film).

[0024] The second object of the present invention is to provide a preparation method of the photocurable adhesive for glass substrate encapsulation as described above, including the following steps: Weigh organosilicon-modified alicyclic epoxy resin, fluorine-modified epoxy resin, flexible acrylate monomer, organosilicon-modified acrylate, adhesion promoter, radical photoinitiator and cationic photoinitiator, and add them into a blender in sequence. Vacuum to a vacuum degree of -0.08 MPa to -0.05 MPa, control the rotation speed at 500 r / min to 1000 r / min, stir for 0.5 h to 2 h, naturally air-dry to room temperature, and then seal and package.

[0025] The third object of the present invention is to provide an application of the photocurable adhesive for glass substrate encapsulation as described above in the encapsulation of chip glass substrates.

[0026] Furthermore, in the above application, the photocurable adhesive for glass substrate encapsulation is encapsulated at the edge of the electronic material through the UV-LIPO (Low-Injection Pressure Overmolding) process, so that the electronic material is effectively protected.

[0027] Furthermore, the electronic material is a glass substrate and an ABF substrate, and the light source wavelength of the UV-LIPO process is 365 nm to 470 nm.

[0028] Compared with the prior art, the present invention has the following technical effects: The photocurable adhesive for glass substrate encapsulation of the present invention has the advantages of high adhesion, especially the adhesion to ABF material is higher than that of conventional thermosetting materials; it has higher heat resistance, better impact resistance and more excellent acid and alkali resistance, and higher aging reliability than conventional materials; it has higher production efficiency. Detailed implementation manners

[0029] The principles and features of the present invention will be described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0030] Synthesis example 1 Preparation of organosilicon-modified alicyclic epoxy resin: Weigh 12.4 g of 1,2-epoxy-4-vinylcyclohexane and mix it evenly with a platinum catalyst, then heat it to 40 °C, dropwise add 200 g of side hydrogen-containing silicone oil, control the dropping rate, and finish dropping in 60 min. During the dropping process, control the temperature not to exceed 60 °C. After dropping, raise the temperature to 80 °C and react for 2 hours to obtain organosilicon-modified alicyclic epoxy resin. The mass content of the platinum catalyst in the reaction system (the total amount of 1,2-epoxy-4-vinylcyclohexane and side hydrogen-containing silicone oil) is 10 ppm.

[0031] Synthesis example 2 Preparation of organosilicon-modified acrylate: Weigh 150 g of double-ended monoalkyl hydroxy silicone (Slok Polymers Co., Ltd., grade 8802F2) and 21 g of isocyanate ethyl acrylate and add them to a three-necked flask. After mixing evenly, raise the temperature to 70 °C - 85 °C and react for 3 hours. Stop the reaction after the NCO completely disappears to obtain organosilicon-modified acrylate.

[0032] Example 1 Accurately weigh the following raw materials: 30 g of organosilicon-modified alicyclic epoxy resin, 10 g of fluorine-modified epoxy resin, 35 g of dodecyl acrylate monomer, 30 g of organosilicon-modified acrylate, 8 g of rosin phenol, 1.6 g of 9,10-dibutoxyanthracene, 0.8 g of IRGACURE 261; Add the above components to a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.08 MPa, stir at 500 r / min for 2 hours, stir evenly, air-dry to room temperature, and then seal and package.

[0033] Example 2 Accurately weigh the following raw materials: 25 g of silicone-modified alicyclic epoxy resin, 10 g of fluorine-modified epoxy resin, 35 g of tridecyl acrylate monomer, 40 g of silicone-modified acrylate, 8 g of rosin phenol, 3 g of benzoin methyl ether, 0.9 g of IRGACURE 250; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.05 MPa, stir at 750 r / min for 1 hour, stir evenly, naturally air-dry to room temperature, and then seal and package.

[0034] Example 3 Accurately weigh the following raw materials: 30 g of silicone-modified alicyclic epoxy resin, 6.4 g of fluorine-modified epoxy resin, 50 g of octadecyl acrylate monomer, 23 g of silicone-modified acrylate, 10 g of rosin phenol, 1 g of photoinitiator TPO, 1 g of IRGACURE 262; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.06 MPa, stir at 700 r / min for 1.5 hours, stir evenly, naturally air-dry to room temperature, and then seal and package.

[0035] Example 4 Accurately weigh the following raw materials: 40 g of silicone-modified alicyclic epoxy resin, 10 g of fluorine-modified epoxy resin, 29 g of dodecyl methacrylate monomer, 24 g of silicone-modified acrylate, 10 g of rosin phenol, 1.5 g of 4,4'-bis(diethylamino)benzophenone, 0.8 g of IRGACURE 262, 0.4 g of IRGACURE 250; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.07 MPa, stir at 800 r / min for 1 hour, stir evenly, naturally air-dry to room temperature, and then seal and package.

[0036] Example 5 Accurately weigh the following raw materials: 30 g of silicone-modified alicyclic epoxy resin, 20 g of fluorine-modified epoxy resin, 45 g of octadecyl methacrylate monomer, 30 g of silicone-modified acrylate, 8 g of rosin phenol, 1.9 g of methyl o-benzoylbenzoate, 0.7 g of IRGACURE 261; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.08 MPa, stir at 1000 r / min for 0.5 hours, stir evenly, naturally air-dry to room temperature, and then seal and package.

[0037] Comparative Example 1 Accurately weigh the following raw materials: CELLOXIDE 2021P 45 g, MBS 15 g, OXT-221 19 g, polycaprolactone diol 12 g, 9,10-dibutoxyanthracene 1.5 g, IRGACURE 261 1.5 g; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.08 MPa, stir at 500 r / min for 2 hours, stir evenly, let it stand naturally to room temperature, and then seal and package.

[0038] Among them, the MBS resin is a terpolymer of methyl methacrylate (M), butadiene (B) and styrene (S) (Arkema Co., Ltd., XT100).

[0039] Comparative Example 2 Accurately weigh the following raw materials: Bisphenol A epoxy resin 45 g, mercaptan curing agent 23 g, latent curing agent 21 g, toughening agent 25 g, stabilizer 0.2 g; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.08 MPa, stir at 500 r / min for 2 hours, stir evenly, let it stand naturally to room temperature, and then seal and package.

[0040] Comparative Example 3 Accurately weigh the following raw materials: Modified silane 75 g, plasticizer 12 g, crosslinking agent 1 g, moisture catalyst 0.5 g, filler 19 g; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.08 MPa, stir at 500 r / min for 2 hours, stir evenly, let it stand naturally to room temperature, and then seal and package.

[0041] Comparative Example 4 Accurately weigh the following raw materials: Organosilicon-modified alicyclic epoxy resin 30 g, fluorine-modified epoxy resin 20 g, octadecyl methacrylate monomer 45 g, polyurethane-modified acrylate 30 g, rosin phenol 5 g, methyl o-benzoylbenzoate 1.9 g, IRGACURE 261 0.7 g; Add the above components into a double planetary power mixer in sequence, evacuate to a vacuum degree of -0.08 MPa, stir at 1000 r / min for 0.5 hour, stir evenly, let it stand naturally to room temperature, and then seal and package.

[0042] Test the performance of each example and comparative example through the following performance tests.

[0043] Curing light source (UV curing): 365 nm LED lamp, light intensity 500 mW / cm2 。

[0044] Modulus: DMA test.

[0045] Peel strength: Tested by universal testing machine, substrates: glass and ABF material.

[0046] Impact resistance test: At a height of 1.8 m, drop 200 times, and judge whether the glass substrate cracks.

[0047] Acid and alkali resistance test: Immerse the encapsulated glass substrate in a hydrochloric acid solution with a mass fraction of 5% and a NaOH solution with a mass fraction of 5% respectively. After soaking for 78 hours, check whether the adhesive film falls off.

[0048] Heat aging test: Place the encapsulated glass substrate in an oven at 150 °C, take it out after 168 hours and observe whether it turns yellow.

[0049] The test results are shown in Table 1.

[0050] Table 1 Performance comparison test results

[0051] As can be seen from the results in Table 1 above, compared with the conventional encapsulation adhesive, the photocurable adhesive of the present invention has a higher peel strength, so that the photocurable adhesive of the present invention has the advantage of high adhesion, especially the adhesion to ABF material is higher than that of conventional materials; it has higher heat resistance, better impact resistance and more excellent acid and alkali resistance, and higher aging reliability than conventional materials; it has higher production efficiency, and the photocurable encapsulation process of the present invention cures faster than the conventional thermal curing and moisture curing encapsulation processes.

[0052] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A photo-curable adhesive for glass substrate encapsulation, characterized in that, Comprising the following components by weight percentage: Silicone-modified alicyclic epoxy resin 20% - 40%; Fluorine-modified epoxy resin 5% - 20%; Flexible acrylate monomer 25% - 45%; Silicone-modified acrylate 20% - 40%; Adhesion promoter 5% - 10%; Free radical photoinitiator 0.3% - 3%; Cationic photoinitiator 0.1% - 2%.

2. The photocurable adhesive for glass substrate encapsulation according to claim 1, wherein The silicone-modified alicyclic epoxy resin has the structure shown in formula (I): （I）， Wherein, a ≥ 10, b ≥ 3, and both a and b are integers.

3. The photocurable adhesive for glass substrate encapsulation according to claim 2, wherein The preparation method of the silicone-modified alicyclic epoxy resin is as follows: Mix 1,2-epoxy-4-vinylcyclohexane and platinum catalyst evenly and heat, dropwise add hydrogen-containing silicone oil on the side, control the temperature below 60 °C during the dropping process, control the dropping rate to be completed within 60 min. After the dropping is completed, raise the temperature to 60 °C - 90 °C and react to obtain the silicone-modified alicyclic epoxy resin.

4. The photocurable adhesive for glass substrate encapsulation according to claim 1, wherein, The fluorine-modified epoxy resin has the structure shown in formula (II): (II).

5. The photocurable adhesive for glass substrate encapsulation according to claim 1, wherein The silicone-modified acrylate has the structure shown in formula (III): (III), Wherein, n is an integer ≥ 10.

6. The photocurable adhesive for glass substrate encapsulation according to claim 5, wherein, The preparation method of the silicone-modified acrylate is as follows: Mix bis-terminal monoalkylhydroxy silicone and ethyl isocyanate acrylate and heat, the reaction temperature is 70 °C - 85 °C, the reaction time is 2 h - 4 h, and terminate the reaction after the NCO completely disappears to obtain the silicone-modified acrylate.

7. The photocurable adhesive for glass substrate encapsulation according to claim 1, characterized in that, The flexible acrylate monomer is selected from any one or two or more of dodecyl acrylate, tridecyl acrylate, octadecyl acrylate, dodecyl methacrylate, tridecyl methacrylate or octadecyl methacrylate.

8. The photocurable adhesive for glass substrate encapsulation according to claim 1, wherein The adhesion promoter is rosin phenol; The free radical photoinitiator is selected from any one or two or more of anthracene derivatives, benzoin derivatives, benzophenone and its derivatives, acetophenone and its derivatives, methyl o-benzoylbenzoate; The cationic photoinitiator is selected from any one or two or more of aromatic diazonium salts, triaryl sulfonium salts, diaryl iodonium salts, aromatic ferrocene salts.

9. A preparation method of a photocurable adhesive for glass substrate encapsulation according to any one of claims 1 to 8, characterized in that, Comprising the following steps: Weigh the silicone-modified alicyclic epoxy resin, fluorine-modified epoxy resin, flexible acrylate monomer, silicone-modified acrylate, adhesion promoter, free radical photoinitiator and cationic photoinitiator, add them into the blender in sequence, evacuate to a vacuum degree of -0.08 MPa to -0.05 MPa, control the rotation speed to be 500 r / min - 1000 r / min, stir for 0.5 h - 2 h, naturally air-dry to room temperature, and seal and package.

10. Application of the photocurable adhesive for glass substrate encapsulation according to any one of claims 1 - 8 in chip glass substrate encapsulation.

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