Room-temperature curing single-component epoxy conductive adhesive as well as preparation method and application thereof

Abstract

The invention discloses a room-temperature curing single-component epoxy conductive adhesive and a preparation method and application thereof, and relates to the technical field of conductive adhesives, the single-component epoxy conductive adhesive is prepared from the following components by weight: 100-140 parts of epoxy resin, 20-25 parts of a flexibilizer, 5-15 parts of an epoxy diluent, 10-15 parts of a curing agent, 5-40 parts of silver powder, 4-6 parts of a curing accelerator, and 5-10 parts of single-walled carbon nanotubes. The epoxy resin is one or more of liquid bisphenol A type epoxy resin and liquid bisphenol F type epoxy resin, and the toughening agent is one of phthalic acid esters, polysulfide rubber or polypropylene glycol diglycidyl ether. According to the room temperature curing single-component epoxy conductive adhesive as well as the preparation method and the application thereof, the single-walled carbon nanotubes and the multi-walled carbon nanotubes are added into the prepared single-component epoxy conductive adhesive, so that the conductivity of the single-component epoxy conductive adhesive can be ensured, the cost of the single-component epoxy conductive adhesive is greatly reduced, and the heat conductivity of the single-component epoxy conductive adhesive can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of conductive adhesives, in particular to a room temperature curing single-component epoxy conductive adhesive and a preparation method and application thereof. Background Art

[0002] Conductive adhesive is an adhesive with certain adhesion and conductivity. It is an ideal choice for semiconductor packaging, electronic component lead connection, printed circuit board repair, and bonding of conductive composite materials. With the rapid development of electronics and microelectronics, people's requirements for electronic components are becoming increasingly miniaturized, and for printed circuit boards, they are pursuing higher density and higher integration, so the development and research of conductive adhesives with high line resolution is particularly important.

[0003] However, traditional tin / lead solder bonding has high temperature, poor controllability, low resolution and complex process. Therefore, we propose a room temperature curing single-component epoxy conductive adhesive and its preparation method and application. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a room temperature curing one-component epoxy conductive adhesive and a preparation method and application thereof, which solve the problems raised in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical scheme: a room temperature curing one-component epoxy conductive adhesive, the one-component epoxy conductive adhesive includes the following components in parts by weight: 100-140 parts of epoxy resin, 20-25 parts of toughening agent, 5-15 parts of epoxy diluent, 10-15 parts of curing agent, 5-40 parts of silver powder, 4-6 parts of curing accelerator, 5-10 parts of single-walled carbon nanotubes, 5-10 parts of multi-walled carbon nanotubes, and 0.2-2 parts of coupling agent.

[0006] Furthermore, the epoxy resin is one or more of liquid bisphenol A epoxy resin and liquid bisphenol F epoxy resin.

[0007] Furthermore, the toughening agent is one of phthalates, polysulfide rubber or polypropylene glycol diglycidyl ether.

[0008] Furthermore, the silver powder is flaky silver powder with an average particle size of 1.5 to 10 μm.

[0009] Furthermore, the epoxy diluent is one or more of ethanol, butanol or acetone.

[0010] Furthermore, the curing agent is an amine curing agent, one or more of dicyandiamide (dicyandiamide), bis(4-amino-3-methylcyclohexyl)methane, and meta-phenylenediamine.

[0011] Furthermore, the curing accelerator is one or more of triethanolamine, 2,4,6-tris(dimethylaminomethyl)phenol, and imidazole metal salt complex, and the coupling agent is one or two of epoxy silane and acyl silane.

[0012] Furthermore, the diameter of the single-walled carbon nanotube is about 0.4-2 nm, the inner diameter of the multi-walled carbon nanotube is about 0.5-50 nm, the number of layers is greater than 3, and the length is 0.5-50 μm.

[0013] Further, the following steps are included:

[0014] (1) adding corresponding weight parts of epoxy resin, toughening agent, conductive silver powder, single-walled carbon nanotubes, and multi-walled carbon nanotubes into a planetary disperser and stirring at high speed, wherein the speed of the high-speed disperser is 100 to 1000 rpm, the number of grindings is 4 to 8 times, stirring for 0.5 to 1 hour, and then grinding to obtain a base material;

[0015] (2) heating the base material to 100°C-120°C, stirring for 1-1.5 hours under vacuum, and then cooling; cooling to room temperature and grinding;

[0016] (3) Adding a diluent, a curing agent, a curing accelerator, and a coupling agent to the ground product, and stirring at high speed under vacuum for 60 to 120 minutes to obtain a single-component epoxy conductive adhesive.

[0017] Furthermore, an application of the room temperature curing single-component epoxy conductive adhesive is applied to semiconductor packaging, electronic component lead connection, and printed circuit board repair.

[0018] The present invention provides a room temperature curing one-component epoxy conductive adhesive and a preparation method and application thereof, which have the following beneficial effects: the one-component epoxy conductive adhesive prepared by the present invention can ensure its conductive performance by adding single-walled carbon nanotubes and multi-walled carbon nanotubes, greatly reduce its cost, and improve thermal conductivity. DETAILED DESCRIPTION

[0019] The following examples are used to illustrate the present invention, but they are not intended to limit the scope of the present invention.

[0020] Example 1

[0021] Add 100 parts of liquid bisphenol A epoxy resin, 20 parts of polypropylene glycol diglycidyl ether, 40 parts of flaky silver powder with an average particle size of 10 μm, 10 parts of single-walled carbon nanotubes with a solid content of 10%, and 10 parts of multi-walled carbon nanotubes with a diameter of 20 to 30 nm and a length of 10 to 30 μm into a planetary disperser, and disperse and stir at a high speed of 1000 rpm for 0.5 h to obtain a base material. Heat the base material to 100° C., keep it under vacuum (<-0.08 Mpa), stir it for 1 h, then cool it down, stir it at a speed of 1000 rpm, and grind it 6 times with a three-roll grinder after cooling. After grinding, add 5 parts of ethanol, 10 parts of dicyandiamide, 5 parts of imidazole salt complex formed by the nitrogen atom at the 3-position of imidazole and metal Ni ion, and 0.4 parts of 3-glycidyloxypropyltrimethoxysilane into the mixer, keep it under vacuum (<-0.08Mpa), stir for 60 minutes, and the stirring speed is 1000rpm.

[0022] Example 2

[0023] Add 100 parts of liquid bisphenol A epoxy resin, 25 parts of polypropylene glycol diglycidyl ether, 20 parts of flaky silver powder with an average particle size of 2 μm, 10 parts of single-walled carbon nanotubes with a solid content of 10%, and 10 parts of multi-walled carbon nanotubes with a tube diameter of 10 to 20 nm and a length of 10 to 30 μm into a planetary disperser, disperse and stir at a high speed of 1000 rpm, and stir for 0.5 hours to obtain a base material. Heat the base material to 100°C, keep it under vacuum (<-0.08Mpa), stir it for 1 hour and then cool it, the stirring speed is 1000 rpm, and grind it with a three-roll grinder for 4 times after cooling. After grinding, add 10 parts of ethanol, 15 parts of dicyandiamide, 6 parts of imidazole salt complex formed by nitrogen atoms at the 3rd position of imidazole and metal Ni ions, and 0.5 parts of KH560 coupling agent into the mixer, keep it under vacuum (<-0.08Mpa), stir it for 60 minutes, and the stirring speed is 1000 rpm.

[0024] Example 3

[0025] Add 120 parts of liquid bisphenol A epoxy resin, 20 parts of polypropylene glycol diglycidyl ether, 40 parts of flaky silver powder with an average particle size of 10 μm, 5 parts of single-walled carbon nanotubes with a solid content of 10%, and 5 parts of multi-walled carbon nanotubes with a diameter of 20 to 30 nm and a length of 10 to 30 μm into a planetary disperser, disperse and stir at a high speed of 1000 rpm, and stir for 0.5 hours to obtain a base material. Heat the base material to 100°C, keep it under vacuum (<-0.08Mpa), stir it for 1 hour and then cool it, the stirring speed is 100 rpm, and grind it with a three-roll grinder for 6 times after cooling. After grinding, add 5 parts of ethanol, 15 parts of dicyandiamide, 5 parts of imidazole salt complex formed by nitrogen atoms at the 3rd position of imidazole and metal Ni ions, and 0.5 parts of KH560 coupling agent into the mixer, keep it under vacuum (<-0.08Mpa), stir it for 60 minutes, and the stirring speed is 100 rpm.

[0026] Example 4

[0027] Add 100 parts of liquid bisphenol A epoxy resin, 20 parts of polypropylene glycol diglycidyl ether, 20 parts of flaky silver powder with an average particle size of 10 μm, 10 parts of single-walled carbon nanotubes with a solid content of 10%, and 10 parts of multi-walled carbon nanotubes with a tube diameter of 20 to 30 nm and a length of 10 to 30 μm into a planetary disperser, disperse and stir at a high speed of 1000 rpm, and stir for 0.5 hours to obtain a base material. Heat the base material to 100°C, keep it under vacuum (<-0.08Mpa), stir it for 1 hour and then cool it, the stirring speed is 1000 rpm, and grind it with a three-roll grinder for 6 times after cooling. After grinding, add 5 parts of ethanol, 10 parts of dicyandiamide, 4 parts of imidazole salt complex formed by nitrogen atoms at the 3rd position of imidazole and metal Ni ions, and 2 parts of KH560 coupling agent into the mixer, keep it under vacuum (<-0.08Mpa), stir it for 60 minutes, and the stirring speed is 1000 rpm.

[0028] Example 5

[0029] The method is basically the same as that of Example 1, except that the epoxy resin is bisphenol F epoxy resin.

[0030] Comparative Example 1

[0031] In this comparative example, no single-walled carbon nanotubes were added, and the rest were the same as described in Example 1.

[0032] Comparative Example 2

[0033] In this comparative example, no multi-walled carbon nanotubes were added, and the rest was the same as described in Example 1.

[0034] The curing condition of the one-component epoxy conductive adhesive in Examples 1 to 5 of the present invention is heating at 80° C., and the curing time is recorded.

[0035] The single-component epoxy conductive adhesives prepared in Examples 1 to 5 and Comparative Examples 1 and 2 were tested for their curing speed, volume resistivity, and thermal conductivity. The results are shown in Table 1:

[0036] Table 1

[0037]

[0038] It can be seen from the data in Table 1 that the conductive adhesive in the present invention can be quickly cured at 80°C, and as the amount added increases, its volume resistivity can be greatly reduced, thereby increasing the conductive performance, while also improving the thermal conductivity of the product and increasing heat dissipation; reducing the addition ratio of silver powder can also greatly reduce costs, so the conductive adhesive provided by the present invention can meet the requirements of industries such as semiconductor packaging, electronic component lead connection, and printed circuit board repair.

[0039] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

Claims

1. A room temperature curing one-component epoxy conductive adhesive, characterized in that: The single-component epoxy conductive adhesive includes the following components in parts by weight: 100-140 parts of epoxy resin, 20-25 parts of toughening agent, 5-15 parts of epoxy diluent, 10-15 parts of curing agent, 5-40 parts of silver powder, 4-6 parts of curing accelerator, 5-10 parts of single-walled carbon nanotubes, 5-10 parts of multi-walled carbon nanotubes, and 0.2-2 parts of coupling agent.

2. The room temperature curing one-component epoxy conductive adhesive according to claim 1, characterized in that: The epoxy resin is one or more of liquid bisphenol A epoxy resin and liquid bisphenol F epoxy resin.

3. The room temperature curing one-component epoxy conductive adhesive according to claim 2, characterized in that: The toughening agent is one of phthalates, polysulfide rubber or polypropylene glycol diglycidyl ether.

4. The room temperature curing one-component epoxy conductive adhesive according to claim 3, characterized in that: The silver powder is flaky silver powder with an average particle size of 1.5 to 10 μm.

5. The room temperature curing one-component epoxy conductive adhesive according to claim 4, characterized in that: The epoxy diluent is one or more of ethanol, butanol or acetone.

6. The room temperature curing one-component epoxy conductive adhesive according to claim 5, characterized in that: The curing agent is an amine curing agent, one or more of dicyandiamide (dicyandiamide), bis(4-amino-3-methylcyclohexyl)methane, and metaphenylenediamine.

7. The room temperature curing one-component epoxy conductive adhesive according to claim 6, characterized in that: The curing accelerator is one or more of triethanolamine, 2,4,6-tris(dimethylaminomethyl)phenol and imidazole metal salt complex, and the coupling agent is one or two of epoxy silane and acyl silane.

8. The room temperature curing one-component epoxy conductive adhesive according to claim 7, characterized in that: The diameter of single-walled carbon nanotubes is about 0.4 to 2 nm, the inner diameter of multi-walled carbon nanotubes is about 0.5 to 50 nm, the number of layers is greater than 3, and the length is 0.5 to 50 μm.

9. A method for preparing a room temperature curing one-component epoxy conductive adhesive as claimed in claim 8, characterized in that: The following steps are involved: (1) adding corresponding weight parts of epoxy resin, toughening agent, conductive silver powder, single-walled carbon nanotubes, and multi-walled carbon nanotubes into a planetary disperser and stirring at high speed, wherein the speed of the high-speed disperser is 100 to 1000 rpm, the number of grindings is 4 to 8 times, stirring for 0.5 to 1 hour, and then grinding to obtain a base material; (2) heating the base material to 100°C-120°C, stirring for 1-1.5 hours under vacuum, and then cooling; cooling to room temperature and grinding; (3) Adding a diluent, a curing agent, a curing accelerator, and a coupling agent to the ground product, and stirring at high speed under vacuum for 60 to 120 minutes to obtain a single-component epoxy conductive adhesive.

10. An application of the room temperature curing one-component epoxy conductive adhesive as claimed in any one of claims 1 to 8, characterized in that: It is used in semiconductor packaging, electronic component lead connection, and printed circuit board repair.

Images