Low-temperature curing UV thermal dual-curing adhesive for assembling camera module and application of low-temperature curing UV thermal dual-curing adhesive

Abstract

The invention discloses a low-temperature curing UV thermal dual-curing adhesive for assembling a camera module and application thereof, and the adhesive is prepared from the following raw materials in parts by mass: 30 to 40 parts of epoxy resin, 5 to 10 parts of acrylate monomer, 19 to 29 parts of thermal curing agent, 2.5 to 6.5 parts of light curing agent, 3 to 5 parts of curing accelerator, 3.6 to 13.6 parts of flexibilizer, 1 to 5 parts of stabilizer, 10 to 40 parts of filler and 0.01 to 0.1 part of pigment. Wherein the light curing agent comprises one or more of acyl phosphine oxides, alpha-hydroxy ketones and carbazole oxime esters. The dual-curing adhesive provided by the invention has no obvious change before and after curing, the shrinkage rate is extremely low, and camera module parts can be protected; and the UV thermal dual-curing adhesive is relatively high in glass transition temperature, and a lens is good in fixity when being used in a vehicle-mounted environment, and is not easy to defocus.

Description

Technical Field

[0001] This invention belongs to the field of dual-curing adhesive technology, specifically relating to a low-temperature curing UV thermal dual-curing adhesive for camera module assembly and its application. Background Technology

[0002] The camera module assembly process typically employs the AA process, or Active Alignment. Continuous adjustments during camera assembly achieve optimal display results, effectively reducing assembly tolerances. The bonding process between the camera module and the base is crucial, requiring the use of suitable adhesive for bonding and filling gaps. AA adhesive is commonly used to bond the lens assembly and image sensor module. The bonding method involves first irradiating the adhesive with UV light to allow it to initially cure after determining the fixed position, followed by further heating to strengthen the bond.

[0003] Using the right adhesive can significantly improve assembly efficiency and reduce defect rates. To prevent deformation and displacement after curing, the adhesive must have extremely low shrinkage. Furthermore, since automotive lenses typically operate in high-temperature environments, the glass transition temperature of this type of adhesive cannot be too low; otherwise, it may cause lens displacement and loss of focus.

[0004] Therefore, there is an urgent need to develop a UV thermal double-curing adhesive with low shrinkage and high glass transition temperature. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of the invention, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0007] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a low-temperature curing UV thermal dual-curing adhesive for camera module assembly.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: comprising, by mass parts of raw materials, 30-40 parts epoxy resin, 5-10 parts acrylate monomer, 19-29 parts thermosetting agent, 2.5-6.5 parts UV curing agent, 3-5 parts curing accelerator, 3.6-13.6 parts toughening agent, 1-5 parts stabilizer, 10-40 parts filler, and 0.01-0.1 parts pigment; The photocuring agent includes one or more of acylphosphine oxides, α-hydroxy ketones, and carbazole oxime esters.

[0009] As a preferred embodiment of the low-temperature curing UV thermal dual-curing adhesive for camera module assembly described in this invention, the epoxy resin includes rigid epoxy resin and flexible epoxy resin. The rigid epoxy resin includes one of a difunctional epoxy resin and a multifunctional epoxy resin, and the flexible epoxy resin includes one of a monofunctional epoxy resin and a difunctional epoxy resin.

[0010] As a preferred embodiment of the low-temperature curing UV-thermal dual-curing adhesive for camera module assembly described in this invention, the rigid epoxy resin has a structure in which glycidyl ether is directly connected to an aromatic ring skeleton, including one of bisphenol A type epoxy resin, phenolic type epoxy resin, and naphthyl epoxy resin; the flexible epoxy resin has a structure in which glycidyl ether is first connected to aliphatic segments and then connected to a cyclic or chain skeleton, including ethylene glycol diglycidyl ether.

[0011] As a preferred embodiment of the low-temperature curing UV thermal dual-curing adhesive for camera module assembly described in this invention, the acrylate monomer includes one or more of dimethacrylate, ethyl acrylate, bisphenol A diacrylate, and isoborneol acrylate.

[0012] In a preferred embodiment of the low-temperature curing UV thermal dual-curing adhesive for camera module assembly described in this invention, the thermal curing agent is a thiol.

[0013] As a preferred embodiment of the low-temperature curing UV thermal dual-curing adhesive for camera module assembly described in this invention, the curing accelerator includes one or more of amines and imidazoles.

[0014] In a preferred embodiment of the low-temperature curing UV thermal dual-curing adhesive for camera module assembly described in this invention, the stabilizer is citric acid.

[0015] As a preferred embodiment of the low-temperature curing UV thermal dual-curing adhesive for camera module assembly described in this invention, the filler includes fumed silica and calcium carbonate.

[0016] Another objective of this invention is to overcome the shortcomings of the prior art and provide an application of a low-temperature curing UV thermal dual-curing adhesive for camera module assembly in camera module assembly.

[0017] To solve the above-mentioned technical problems, the present invention provides the following technical solution: the application includes, After the camera module is glued on, first use 100~150 mw / cm 2 Irradiate the bonded area with a 365nm LED light for 10-20 seconds to pre-cure it, and then place the parts in an oven at 60-70℃ for 1-1.5 hours to cure.

[0018] Beneficial effects of this invention: (1) The dual-curing adhesive provided by the present invention has no significant changes before and after curing and has an extremely low shrinkage rate, which is beneficial to protect the camera module components; (2) In addition, the UV thermal dual-curing adhesive of the present invention has a high glass transition temperature, which makes it easy to fix the lens in the vehicle environment and prevents the lens from going out of focus. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the preparation process of the low-temperature curing UV-thermal dual-curing adhesive of Example 1 of the present invention.

[0021] Figure 2 The transmittance curves are for adhesives with different carbon black addition amounts in Examples 1 and 3-4 of the present invention. Detailed Implementation

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0024] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0025] The specific curing method of the adhesive in this invention is as follows: Apply adhesive to the surface of the LCP substrate, cover with a piece of colorless transparent tempered glass with dimensions of 25*100*5mm, controlling the thickness to 0.1~0.3mm, and first use 100~150mw / cm². 2 Irradiate the bonded area with a 365nm LED light for 10-20 seconds to pre-cure it, and then place the parts in an oven at 60°C for 1 hour to cure them.

[0026] The raw materials used in this invention are shown in Table 1.

[0027] Table 1 Raw materials for UV thermo-curable adhesives

[0028] Example 1 This embodiment provides a low-temperature curing UV-curing dual-curing adhesive for camera module assembly, comprising, by mass parts of raw materials: 30 parts of bisphenol A type epoxy resin, 10 parts of ethylene glycol diglycidyl ether, 8 parts of isobornyl acrylate, 29 parts of thiol, 1 part of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts of 1-hydroxycyclohexylphenyl ketone, 1 part of OXE02, 5 parts of curing accelerator PN-23, 3.6 parts of toughening agent MX-154, 3 parts of citric acid, 2 parts of fumed silica, 20 parts of calcium carbonate, and 0.05 parts of carbon black; The specific preparation method is as follows: (1) Weigh out the following raw materials according to the above proportions: bisphenol A epoxy resin, ethylene glycol diglycidyl ether, isobornyl acrylate, thiol, phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxycyclohexylphenyl ketone, OXE02, curing accelerator PN-23, toughening agent MX-154, citric acid, fumed silica, calcium carbonate, and carbon black; (2) Add three photoinitiators, namely phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 1-hydroxycyclohexylphenyl ketone and OXE02, to two epoxy resins, namely bisphenol A type epoxy resin and ethylene glycol diglycidyl ether, and stir at room temperature until completely dissolved to form a homogeneous resin system. (3) To the resin system obtained in step (2), add isobornyl acrylate, toughening agent MX-154, thiol, curing accelerator PN-23, fumed silica, citric acid, calcium carbonate and carbon black in sequence to obtain a composite system. (4) The composite system obtained in step (3) is stirred evenly using a high-speed disperser at a speed of 1500 r / min to ensure that the system is free of agglomeration and has uniform particle size, thus obtaining the UV thermal double curing adhesive.

[0029] Figure 1 A flowchart of the preparation process for Example 1 is shown.

[0030] Example 2 This embodiment provides a low-temperature curing UV-curing dual-curing adhesive for camera module assembly, comprising, by mass parts of raw materials: 30 parts of bisphenol A type epoxy resin, 10 parts of ethylene glycol diglycidyl ether, 8 parts of isobornyl acrylate, 29 parts of thiol, 1 part of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts of 1-hydroxycyclohexylphenyl ketone, 0.5 parts of OXE02, 5 parts of curing accelerator PN-23, 3.6 parts of toughening agent MX-154, 3 parts of citric acid, 2 parts of fumed silica, 20 parts of calcium carbonate, and 0.05 parts of carbon black; The specific preparation method is the same as in Example 1.

[0031] Example 3 This embodiment provides a low-temperature curing UV-curing dual-curing adhesive for camera module assembly, comprising, by mass parts of raw materials: 30 parts of bisphenol A type epoxy resin, 10 parts of ethylene glycol diglycidyl ether, 8 parts of isobornyl acrylate, 19 parts of thiol, 1 part of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts of 1-hydroxycyclohexylphenyl ketone, 0.5 parts of OXE02, 3 parts of curing accelerator PN-23, 3.6 parts of toughening agent MX-154, 3 parts of citric acid, 2 parts of fumed silica, 20 parts of calcium carbonate, and 0.05 parts of carbon black; The specific preparation method is the same as in Example 1.

[0032] The adhesives prepared in Examples 1-3 were cured, and it was found that all the adhesives in Examples 1-3 could be cured within 1 hour at 60°C. Subsequently, their curing depth, adhesion, glass transition temperature and shrinkage rate were tested, and the results are shown in Table 1.

[0033] Table 1 Comparison of adhesive properties with different formulations

[0034] As can be seen from Table 1, the adhesive prepared in Example 1 has the highest curing depth and high adhesion, as well as the highest glass transition temperature and the lowest shrinkage. The curing effect and glass transition temperature of Examples 2 and 3 are slightly lower than those of Example 1, and the shrinkage rate is also slightly higher than that of Example 1, but their shrinkage rate is less than 2%, their glass transition temperature is higher than 50°C, and their curing depth is around 0.20.

[0035] Comparative Example 1 This comparative example is used to investigate the effect of the ratio of acrylate monomers on the properties of UV thermosetting adhesives. The difference from Example 1 is that the ratio of acrylate monomers is adjusted, specifically by mass parts of the raw materials, including: 30 parts of bisphenol A type epoxy resin, 10 parts of ethylene glycol diglycidyl ether, 10 parts of isobornyl acrylate, 29 parts of thiol, 1 part of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts of 1-hydroxycyclohexylphenyl ketone, 0.3 parts of OXE02, 5 parts of curing accelerator PN-23, 3.6 parts of toughening agent MX-154, 3 parts of citric acid, 2 parts of fumed silica, 20 parts of calcium carbonate, and 0.05 parts of carbon black; The specific preparation method is the same as in Example 1.

[0036] Comparative Example 2 This comparative example is used to investigate the effect of epoxy resin ratio on the performance of UV thermal dual-curing adhesive. The difference from Example 1 is that the ratio of epoxy resin 128 is adjusted, specifically by mass parts of the raw materials, including: 10 parts bisphenol A type epoxy resin, 30 parts ethylene glycol diglycidyl ether, 5 parts isobornyl acrylate, 29 parts thiol, 1 part phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts 1-hydroxycyclohexylphenyl ketone, 0.5 parts OXE02, 5 parts curing accelerator PN-23, 3.6 parts toughening agent MX-154, 3 parts citric acid, 2 parts fumed silica, 20 parts calcium carbonate, and 0.05 parts carbon black; The specific preparation method is the same as in Example 1.

[0037] Example 4 This embodiment is used to investigate the effect of carbon black dosage on the performance of UV thermal dual-curing adhesive. The difference from Example 1 is that only the amount of carbon black is adjusted to 0.01 and 0.02 parts respectively, while the rest of the formulation is the same as in Example 1; the specific preparation method is the same as in Example 1.

[0038] Comparative Example 3 This comparative example is used to investigate the effect of carbon black dosage on the performance of UV thermal dual-curing adhesive. The difference from Example 1 is that only the amount of carbon black is adjusted to 0.1 parts, while the rest of the formulation is the same as in Example 1; the specific preparation method is the same as in Example 1.

[0039] The adhesives prepared in Comparative Examples 1-3 were cured, and their curing depth, adhesion, glass transition temperature, and shrinkage were tested. The results are shown in Table 2.

[0040] Table 2 Comparison of adhesive properties with different formulations

[0041] As can be seen from Example 1 and Comparative Example 1 in Table 1, increasing the proportion of acrylate increases the shrinkage rate of the adhesive and reduces the overall adhesive strength. Comparing Example 1 and Comparative Example 2, it can be seen that reducing epoxy resin 128 leads to a significant decrease in adhesive strength and an increase in shrinkage rate. Comparing Example 1 and Comparative Example 3, it can be seen that adding an excess of pigment carbon black up to 0.1 parts has little effect on the adhesive strength after thermosetting, but it does affect the curing depth of the adhesive.

[0042] The transmittance curves of adhesives with different carbon black addition amounts in Examples 1, 4, and Comparative Example 3 were tested, and the results are as follows: Figure 2 As shown. From Figure 2 As can be seen, an addition of 0.05 parts of carbon black yields the best results, producing a black color rather than a gray one, while still achieving a good curing depth. Increasing the carbon black content to 0.1 parts leads to a decrease in curing depth.

[0043] Comparative Example 4 The difference between this comparative example and Example 1 is that the thermosetting agent thiol is replaced with hot acid, and no corresponding curing accelerator is added. All other proportions are the same as in Example 1, specifically based on the mass fractions of the raw materials, including: 30 parts of bisphenol A type epoxy resin, 10 parts of ethylene glycol diglycidyl ether, 8 parts of isobornyl acrylate, 1 part of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts of 1-hydroxycyclohexylphenyl ketone, 1 part of OXE02, 1 part of hot acid, 3.6 parts of toughening agent MX-154, 3 parts of citric acid, 2 parts of fumed silica, 20 parts of calcium carbonate, and 0.05 parts of carbon black; The specific preparation method is the same as in Example 1.

[0044] Comparative Example 5 The difference between this comparative example and Example 1 is that only the curing accelerator PN-23 is changed to HS2300, while the rest of the formulation is the same as in Example 1; the specific preparation method is the same as in Example 1.

[0045] Comparative Example 6 The difference between this comparative example and comparative example 5 is that the thermosetting agent thiol is changed to the thermosetting agent Capcure® GPM-888, and the rest of the formulation is the same as in example 1; the specific preparation method is the same as in example 1.

[0046] Comparative Example 7 The difference between this comparative example and Example 1 is that only the amount of the thermosetting agent thiol is adjusted to 18 parts; the rest of the formulation is the same as in Example 1, specifically in parts by mass of the raw materials, including: 30 parts of bisphenol A type epoxy resin, 10 parts of ethylene glycol diglycidyl ether, 8 parts of isobornyl acrylate, 18 parts of thiol, 1 part of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts of 1-hydroxycyclohexylphenyl ketone, 1 part of OXE02, 5 parts of curing accelerator, 3.6 parts of toughening agent MX-154, 3 parts of citric acid, 2 parts of fumed silica, 20 parts of calcium carbonate, and 0.05 parts of carbon black; The specific preparation method is the same as in Example 1.

[0047] Comparative Example 8 This comparative example investigates the effect of the toughening resin ratio on the performance of a UV-curable dual-curing adhesive. The difference from Example 1 is that no toughening resin is added, and the amount of curing accelerator is reduced to 2.5 parts. All other formulations are the same as in Example 1, specifically based on the mass parts of the raw materials, including: The following ingredients were used: 30 parts bisphenol A epoxy resin, 10 parts ethylene glycol diglycidyl ether, 8 parts isobornyl acrylate, 29 parts thiol, 1 part phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 2 parts 1-hydroxycyclohexylphenyl ketone, 1 part OXE02, 2.5 parts curing accelerator PN-23, 3 parts citric acid, 2 parts fumed silica, 20 parts calcium carbonate, and 0.05 parts carbon black; the specific preparation method is the same as in Example 1.

[0048] The adhesives prepared in Comparative Examples 4-8 were cured, and their curing depth, adhesion, glass transition temperature, and shrinkage were tested. The results are shown in Table 3.

[0049] Table 3 Comparison of adhesive properties with different formulations

[0050] As shown in Comparative Example 4 in Table 3, the formulation system of this invention is only suitable for hot alcohol systems and cannot be cured using hot acid systems. Comparative Example 5 shows that the curing accelerator has a significant impact on the adhesive properties; using HS2300 as a curing accelerator leads to a significant decrease in adhesive strength and glass transition temperature, while also increasing shrinkage. Comparing Example 1 and Comparative Example 6, it was found that the type of thermosetting agent also has a significant impact on the curing effect of the adhesive. Only by using the thermosetting agent in this invention can excellent curing results be achieved, resulting in a low shrinkage rate and a high glass transition temperature after curing. Furthermore, Comparative Examples 7 and 8 show that the amount of thermosetting agent also has a significant impact on the adhesive strength of the cured adhesive; the addition of toughening resin is beneficial for improving the adhesive strength and reducing shrinkage.

[0051] In summary, by optimizing the formulation of the UV thermal dual-curing adhesive, the present invention yields a dual-curing adhesive that exhibits no significant changes before and after curing, with extremely low shrinkage, which is beneficial for protecting camera module components. Furthermore, the UV thermal dual-curing adhesive of the present invention has a high glass transition temperature, resulting in good lens fixation in automotive environments and reducing the likelihood of lens defocusing.

[0052] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A low-temperature curing UV-thermal dual-curing adhesive for camera module assembly, characterized in that: Based on the mass fractions of raw materials, including, 30-40 parts epoxy resin, 5-10 parts acrylate monomer, 19-29 parts thermosetting agent, 2.5-6.5 parts UV curing agent, 3-5 parts curing accelerator, 3.6-13.6 parts toughening agent, 1-5 parts stabilizer, 10-40 parts filler, and 0.01-0.1 parts pigment; The photocuring agent includes one or more of acylphosphine oxides, α-hydroxy ketones, and carbazole oxime esters.

2. The low-temperature curing UV-thermal dual-curing adhesive for camera module assembly as described in claim 1, characterized in that: The epoxy resin includes rigid epoxy resin and flexible epoxy resin; The rigid epoxy resin includes one of a difunctional epoxy resin and a multifunctional epoxy resin, and the flexible epoxy resin includes one of a monofunctional epoxy resin and a difunctional epoxy resin.

3. The low-temperature curing UV-thermal dual-curing adhesive for camera module assembly as described in claim 2, characterized in that: The rigid epoxy resin has a structure in which glycidyl ether is directly connected to an aromatic ring skeleton, including one of bisphenol A type epoxy resin, phenolic type epoxy resin, and naphthyl epoxy resin; the flexible epoxy resin has a structure in which glycidyl ether is first connected to an aliphatic segment and then connected to a cyclic or chain skeleton, including ethylene glycol diglycidyl ether.

4. The low-temperature curing UV-thermal dual-curing adhesive for camera module assembly as described in claim 1, characterized in that: The acrylate monomers include one or more of dimethacrylate, ethyl acrylate, bisphenol A diacrylate, and isobornyl acrylate.

5. The low-temperature curing UV-thermal dual-curing adhesive for camera module assembly as described in claim 1, characterized in that: The thermosetting agent is a thiol.

6. The low-temperature curing UV-thermal dual-curing adhesive for camera module assembly as described in claim 1, characterized in that: The curing accelerator includes one or more of amines and imidazoles.

7. The low-temperature curing UV-thermal dual-curing adhesive for camera module assembly as described in claim 1, characterized in that: The stabilizer is citric acid.

8. The low-temperature curing UV-thermal dual-curing adhesive for camera module assembly as described in claim 1, characterized in that: The filler includes fumed silica and calcium carbonate.

9. The application of the low-temperature curing UV thermal dual-curing adhesive as described in any one of claims 1 to 8 in camera module assembly.

10. The application as described in claim 9, characterized in that: The applications include, After the camera module is glued on, first use 100~150 mw / cm 2 Irradiate the bonded area with a 365nm LED light for 10-20 seconds to pre-cure it, and then place the parts in an oven at 60-70℃ for 1-1.5 hours to cure.

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