High-stable anisotropic conductive adhesive film and preparation method thereof

Abstract

The application discloses a kind of high-stability anisotropic conductive adhesive film and preparation method thereof, it is related to conductive adhesive film technical field, including the following components are made: acrylate end-capped hyperbranched organic silicon modified polyurethane, Meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, N-vinyl oxazolidinone, bis (1-vinylimidazole-2-) ketone, N-acryloyl morpholine, 1,3-bis (oxiranylmethyl) -5- (2-propenyl) -1,3,5-triazine-2,4,6 (1H,3H,5H) -trione, 1,4-diamino-2,3-dicyanoanthraquinone, 9,9-di [(2,3-epoxypropoxy) phenyl] fluorene, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline, conductive particle, coupling agent, initiator, solvent.The adhesive film has high peel strength, good conductivity, sufficient moisture and heat aging resistance, and long service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of conductive adhesive film, in particular to a high-stability anisotropic conductive adhesive film and a preparation method thereof. BACKGROUND

[0002] Anisotropic conductive adhesive film (ACF) is a new type of microelectronic assembly connection material composed of resin, conductive filler, initiator and curing agent, etc. It has the characteristics of low curing temperature, simple interconnection process, ultra-fine pitch, etc. It is an important electronic packaging material to replace soldering and is widely used in the design of household electronic products, especially in the application of liquid crystal display (LCD). It can be used to form the binding structure between the display panel and the circuit layer.

[0003] The existing anisotropic conductive adhesive film has defects such as low bonding strength, large resistivity, insufficient moisture and heat aging resistance, and short service life. In order to solve the above problems, a high-stability ACF adhesive with ultra-long storage and a preparation method thereof are disclosed in Chinese patent application No. CN118325525A. The ACF adhesive is processed from raw materials including the following weight parts: t-butyl cyclohexyl acrylate modified polytetrafluoroethylene 10-30 parts, modified polymethyl methacrylate 20-50 parts, conductive particles 1-10 parts, rubber 10-30 parts, silane coupling agent 20-40 parts, first solvent 5-10 parts, and first initiator 1-10 parts. The invention adds t-butyl cyclohexyl acrylate modified polytetrafluoroethylene in the acrylate ACF, which can effectively improve the processability of polytetrafluoroethylene and the compatibility with other materials, and also improve the water resistance of acrylate ACF. It has important significance for the design and preparation of composite materials and can meet the application requirements of different fields. However, the moisture and heat aging resistance and conductivity of the ACF adhesive still need to be further improved.

[0004] Therefore, it is necessary to develop a high-stability anisotropic conductive adhesive film with high peel strength, good conductivity, sufficient moisture and heat aging resistance, and long service life, and a preparation method thereof, which meets the market demand, has wide market value and application prospect, and has very important significance for promoting the development of the field of anisotropic conductive adhesive film. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and provide a high-stability anisotropic conductive adhesive film with high peel strength, good conductivity, sufficient moisture and heat aging resistance, and long service life, and a preparation method thereof.

[0006] To achieve the above object, the technical scheme adopted by the present application is: a high-stability anisotropic conductive adhesive film, which is prepared from the following components in parts by weight: acrylate-terminated hyperbranched organosilicon modified polyurethane 35-45 parts, Meso-tetramethyl-meso-tetrakis-p-aminophenyl calix[4]pyrrole 3-5 parts, N-vinyl oxazolidinone 2-4 parts, bis(1-vinylimidazole-2-) ketone 2-4 parts, N-acryloyl morpholine 1-3 parts, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 3-5 parts, 1,4-diamino-2,3-dicyanoanthraquinone 1-3 parts, 9,9-bis[(2,3-epoxypropoxy)phenyl]fluorene 1-3 parts, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline 0.1-0.3 parts, conductive particles 5-15 parts, coupling agent 0.5-1 part, initiator 1-2 parts, and solvent 30-40 parts.

[0007] Preferably, the source of the acrylate-terminated hyperbranched organosilicon modified polyurethane has no special requirements, and in an embodiment of the present application, the acrylate-terminated hyperbranched organosilicon modified polyurethane is prepared according to the method of Example 1 of the Chinese invention patent with the authorization announcement number CN111393608B.

[0008] Preferably, the preparation method of the Meso-tetramethyl-meso-tetrakis-p-aminophenyl calix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetrakis-p-aminophenyl calix[4]pyrrole [J]. Chemical reagents, 2002 (6): 344-345.

[0009] Preferably, the conductive particles are one or more selected from metal nickel balls, gold balls, nickel / gold balls, and resin microspheres coated with a nickel and / or gold layer.

[0010] Preferably, the resin microspheres are any one of polystyrene microspheres, polyaniline microspheres, polymethyl methacrylate microspheres, polyacrylamide microspheres, polyvinyl alcohol microspheres, and polycaprolactone microspheres.

[0011] Preferably, the average diameter of the conductive particles is 3-40 µm.

[0012] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0013] Preferably, the initiator is a mixture of dibenzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:(3-5).

[0014] Preferably, the solvent is any one of acetone, ethyl acetate, butanone, toluene, N,N-dimethylformamide.

[0015] Another object of the present application is to provide a preparation method of the high-stable anisotropic conductive adhesive film, comprising the following steps:

[0016] Step S1, uniformly mixing the components by weight parts to obtain the conductive adhesive;

[0017] Step S2, defoaming the conductive adhesive, preparing a wet film with a wet film preparation device, and obtaining the high-stable anisotropic conductive adhesive film after drying.

[0018] Preferably, the drying temperature is 85-95℃, and the time is 10-20min.

[0019] Preferably, the thickness of the high-stable anisotropic conductive adhesive film is 10-60μm.

[0020] Due to the use of the above technical solutions, the present application has the following beneficial effects:

[0021] (1) The preparation method of the high-stable anisotropic conductive adhesive film disclosed by the present application has the advantages of simple process, convenient and easy operation, high preparation efficiency and product qualification rate, low dependence on equipment, low energy consumption, suitability for continuous large-scale production, and high popularization and application value.

[0022] (2) The high-stable anisotropic conductive adhesive film disclosed by the present application is prepared from the following components by weight parts: acrylate-terminated hyperbranched organosilicon modified polyurethane 35-45 parts, Meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole 3-5 parts, N-vinyl oxazolidinone 2-4 parts, bis(1-vinylimidazole-2-) ketone 2-4 parts, N-acryloyl morpholine 1-3 parts, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 3-5 parts, 1,4-diamino-2,3-dicyanoanthraquinone 1-3 parts, 9,9-bis[(2,3-epoxypropoxy)phenyl]fluorene 1-3 parts, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline 0.1-0.3 parts, conductive particles 5-15 parts, coupling agent 0.5-1 part, initiator 1-2 parts, and solvent 30-40 parts. Through the mutual cooperation between the components, the prepared high-stable anisotropic conductive adhesive film has the advantages of high peel strength, good conductivity, sufficient wet heat aging resistance, and long service life.

[0023] (3) The high-stability anisotropic conductive adhesive film disclosed in the present application, through reasonable selection of the types and amount of each component, introduces amino groups, ether bonds, ketone groups, morpholine groups, quinoxaline groups and hydroxyl groups formed by ring opening of epoxy groups in the adhesive film at the same time, effectively improves the peeling strength; the selected components contain more cyclic structures, such as imidazole groups, morpholine groups, triazone groups, fluorene groups and quinoxaline groups, the mutual cooperation of these structures makes the rigidity of the crosslinked polymer stronger and the glass transition temperature higher, and further makes the moisture and heat aging resistance and stability of the adhesive film better; 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione contains both epoxy groups and double bonds, so that the crosslinking density is increased, the system adopts preliminary polymerization and curing of the double bonds and curing after hot pressing of the epoxy, so that the polymer forms an interpenetrating network structure, and the moisture and heat aging resistance of the polymer is greatly enhanced.

[0024] (4) The high-stability anisotropic conductive adhesive film disclosed in the present application contains components containing unsaturated olefin bonds, which will undergo preliminary curing reaction under the action of an initiator, and components containing epoxy groups, which can also undergo ring opening reaction with components containing amino groups through hot pressing during use, so that the adhesive film forms an interpenetrating network structure, improves the modulus of the polymer, and the conductive particles can be fixed in the adhesive film layer during the hot pressing process, without slipping, avoiding short circuit, and the contact between the particles in the vertical direction is more compact, which can effectively improve the conductivity, further improve the stability, peeling strength and moisture and heat aging resistance of the adhesive film, and further prolong the service life. DETAILED DESCRIPTION

[0025] The following description is provided to enable any person skilled in the art to practice the present application. The preferred embodiments in the following description are only examples of how the present application can be made and used.

[0026] Example 1

[0027] A high-stability anisotropic conductive adhesive film comprises the following components in parts by weight: acrylate-terminated hyperbranched organosilicon modified polyurethane 35 parts, Meso-tetramethyl-meso-tetra-p-aminophenyl calix[4]pyrrole 3 parts, N-vinyl oxazolidinone 2 parts, bis(1-vinylimidazole-2-)ketone 2 parts, N-acryloylmorpholine 1 part, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 3 parts, 1,4-diamino-2,3-dicyanoanthraquinone 1 part, 9,9-bis[(2,3-epoxypropoxy)phenyl]fluorene 1 part, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline 0.1 part, conductive particles 11 parts, coupling agent 0.5 part, initiator 1 part, solvent 30 parts.

[0028] The acrylate-terminated hyperbranched silicone-modified polyurethane is made according to the method of Example 1 of the Chinese invention patent with the authorized announcement number CN111393608B; the preparation method of Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole [J]. Chemical reagents, 2002 (6): 344-345.

[0029] The conductive particles are metal nickel balls; the average diameter of the conductive particles is 10 μm; the coupling agent is silane coupling agent KH550; the initiator is a mixture of dibenzoyl peroxide and azobisisobutyronitrile with a mass ratio of 1:3; and the solvent is acetone.

[0030] A preparation method of the high-stability anisotropic conductive adhesive film includes the following steps:

[0031] Step S1, uniformly mix the components by weight parts to obtain a conductive adhesive;

[0032] Step S2, remove bubbles from the conductive adhesive, prepare a wet film with a wet film preparation device, and obtain a high-stability anisotropic conductive adhesive film after drying; the drying temperature is 85℃, and the drying time is 10 min; the thickness of the high-stability anisotropic conductive adhesive film is 25 μm.

[0033] Example 2

[0034] A high-stability anisotropic conductive adhesive film is made of the following components by weight parts: acrylate-terminated hyperbranched silicone-modified polyurethane 37 parts, Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole 3.5 parts, N-vinyl oxazolidinone 2.5 parts, bis(1-vinylimidazol-2-) ketone 2.5 parts, N-acryloyl morpholine 1.5 parts, 1,3-bis(oxazolidinylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 3.5 parts, 1,4-diamino-2,3-dicyanoanthraquinone 1.5 parts, 9,9-bis[(2,3-epoxypropoxy)phenyl]fluorene 1.5 parts, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline 0.15 parts, conductive particles 12 parts, coupling agent 0.6 parts, initiator 1.2 parts, and solvent 33 parts.

[0035] The acrylate-terminated hyperbranched silicone-modified polyurethane is made according to the method of Example 1 of the Chinese invention patent with the authorized announcement number CN111393608B; the preparation method of Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole [J]. Chemical reagents, 2002 (6): 344-345.

[0036] The conductive particles are gold balls; the average diameter of the conductive particles is 15 μm; the coupling agent is silane coupling agent KH560; the initiator is a mixture of dibenzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:3.5; and the solvent is ethyl acetate.

[0037] A preparation method of the high-stability anisotropic conductive adhesive film includes the following steps:

[0038] Step S1, uniformly mix the components by weight parts to obtain a conductive adhesive;

[0039] Step S2, remove bubbles from the conductive adhesive, prepare a wet film with a wet film preparation device, and obtain a high-stability anisotropic conductive adhesive film after drying; the drying temperature is 87℃, and the drying time is 13 min; the thickness of the high-stability anisotropic conductive adhesive film is 25 μm.

[0040] Example 3

[0041] A high-stability anisotropic conductive adhesive film is made of the following components in parts by weight: acrylate-terminated hyperbranched silicone-modified polyurethane 40 parts, Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole 4 parts, N-vinyl oxazolidinone 3 parts, bis(1-vinylimidazol-2-) ketone 3 parts, N-acryloyl morpholine 2 parts, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 4 parts, 1,4-diamino-2,3-dicyanoanthraquinone 2 parts, 9,9-bis[(2,3-epoxypropoxy)phenyl]fluorene 2 parts, 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline 0.2 parts, conductive particles 13 parts, coupling agent 0.7 parts, initiator 1.5 parts, and solvent 35 parts.

[0042] The acrylate-terminated hyperbranched silicone-modified polyurethane is made according to the method of Example 1 of the Chinese invention patent with the authorized announcement number CN111393608B; the preparation method of Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole is described in: Guo Yong, Shao Shijun, He Lijun, et al. Synthesis and characterization of Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole [J]. Chemical reagents, 2002 (6): 344-345.

[0043] The conductive particles are metal nickel balls; the average diameter of the conductive particles is 20 μm; the coupling agent is silane coupling agent KH570; the initiator is a mixture of dibenzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:4; and the solvent is butanone.

[0044] A preparation method of the high-stability anisotropic conductive adhesive film, comprising the following steps:

[0045] Step S1, uniformly mixing the components according to the weight parts to obtain a conductive adhesive;

[0046] Step S2, defoaming the conductive adhesive, preparing a wet film with a wet film preparation device, and obtaining a high-stability anisotropic conductive adhesive film after drying; the drying temperature is 89℃, and the drying time is 15 min; the thickness of the high-stability anisotropic conductive adhesive film is 25 μm.

[0047] Comparative Example 1

[0048] A high-stability anisotropic conductive adhesive film and a preparation method thereof, which are basically the same as those of Example 1, except that p-phenylenediamine is used instead of Meso-tetramethyl-meso-tetrakis-p-aminophenylcalix[4]pyrrole and N-acryloylmorpholine.

[0049] Comparative Example 2

[0050] A high-stability anisotropic conductive adhesive film and a preparation method thereof, which are basically the same as those of Example 1, except that p-phenylenediamine is used instead of 1,4-diamino-2,3-dicyanoanthraquinone and 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline.

[0051] In order to further illustrate the beneficial technical effects of the high-stability anisotropic conductive adhesive film involved in the embodiments of the present application, the high-stability anisotropic conductive adhesive films involved in Examples 1-3 and Comparative Examples 1-2 are tested for relevant properties; the test results are shown in Table 1, and the test methods are as follows:

[0052] (1) 90° peeling strength: each example of conductive adhesive film was placed between ITO glass and flexible circuit, and was pressed by using K-880C constant temperature hot press of Kaijingwei; the pressing pressure was 0.1 MPa; the temperature was 150℃; the time was 15s, and the post-processing temperature was 25℃ (the bonding width x length was 28mm x 38mm), the 90° peeling strength between the conductive adhesive film bonding ITO glass and flexible circuit was tested by using 5969 electronic universal material testing machine of Instron Company of USA, and the peeling speed was 10mm / min;

[0053] (2) humidity and heat aging resistance: each example of high-stability anisotropic conductive adhesive film was placed in an environment condition of 85℃ and 85% relative humidity for 1000 hours, and after cooling to room temperature, the 90° peeling strength was detected again according to the method in (1), and the retention rate of 90° peeling strength was calculated, the greater the value, the better the humidity and heat aging resistance.

[0054] (3) conduction resistance: the resistance was tested by using Keithley resistance measuring instrument, and the four-probe method was used to test the resistance.

[0055] From table 1, it can be seen that the high-stability anisotropic conductive adhesive film in each embodiment of the present application has better peeling strength, humidity and heat aging resistance, and good conductivity compared with the comparative product, and the combination use of Meso-tetramethyl-meso-tetra-p-aminophenyl cup [4] pyrrole, N-acryloyl morpholine, 1,4-diamino-2,3-dicyano anthraquinone and 1,4-diacryloyl-1,2,3,4-tetrahydro-6,7-dimethyl quinoxaline is beneficial to improving the above-mentioned properties.

[0056] Table 1

[0057] Item 90° peel strength on-state resistance moisture heat aging resistance Unit N / cm Ω ％ Example 1 12.5 0.10 99.27 Example 2 12.8 0.15 99.49 Example 3 13.0 0.17 99.69 Comparative Example 1 9.9 0.15 95.38 Comparative Example 2 10.6 0.13 94.15

[0058] The above examples are only for illustrating the technical concept and characteristics of the present application, the purpose is to enable the person skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application, any equivalent changes or modifications made according to the spirit and essence of the present application should be covered in the protection scope of the present application.

Claims

1. A highly stable anisotropic conductive adhesive film, characterized by, The components are prepared by mixing the following components by weight parts: acrylate-terminated hyperbranched silicone-modified polyurethane 35-45 parts, Meso-tetramethyl-meso-tetra-p-aminophenylcalix[4]pyrrole 3-5 parts, N-vinyl oxazolidinone 2-4 parts, bis(1-vinylimidazol-2-) ketone 2-4 parts, N-acryloyl morpholine 1-3 parts, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 3-5 parts, 1,4-diamino-2,3-dicyanoanthraquinone 1-3 parts, 9,9-bis[(2,3-epoxypropoxy)phenyl]fluorene 1-3 parts, 1,4-di-acryloyl-1,2,3,4-tetrahydro-6,7-dimethylquinoxaline 0.1-0.3 parts, conductive particles 5-15 parts, coupling agent 0.5-1 part, initiator 1-2 parts, solvent 30-40 parts; the conductive particles are selected from any one of metal nickel balls, gold balls.

2. The high-stable anisotropic conductive adhesive film according to claim 1, wherein The average diameter of the conductive particles is 3-40 μm.

3. The high-stable anisotropic conductive adhesive film according to claim 1, wherein The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

4. The high-stable anisotropic conductive adhesive film according to claim 1, wherein The initiator is a mixture of dibenzoyl peroxide and azobisisobutyronitrile in a mass ratio of 1:(3-5).

5. The high-stable anisotropic conductive adhesive film according to claim 1, wherein The solvent is any one of acetone, ethyl acetate, butanone, toluene, and N,N-dimethylformamide.

6. A method for preparing the high-stable anisotropic conductive adhesive film according to any one of claims 1-5, characterized in that, The method comprises the following steps: Step S1, uniformly mixing the components by weight parts to obtain conductive adhesive; Step S2, defoaming the conductive adhesive, preparing a wet film with a wet film preparer, and obtaining a high-stability anisotropic conductive adhesive film after drying.

7. The method for preparing the highly stable anisotropic conductive film according to claim 6, characterized in that, The drying temperature is 85-95 °C, and the drying time is 10-20 min.

8. The method for preparing the highly stable anisotropic conductive film according to claim 6, characterized in that, The thickness of the high-stability anisotropic conductive adhesive film is 10-60 μm.