High-adhesion low-temperature curing conductive silver paste and preparation method thereof

Abstract

The invention provides high-adhesion low-temperature curing conductive silver paste and a preparation method of the high-adhesion low-temperature curing conductive silver paste, and relates to the technical field of conductive silver paste. 8 to 12 parts of polymer resin; 1-3 parts of a curing agent; 20 to 40 parts of an organic solvent; 1-3 parts of a plasticizer; 10 to 40 parts of metal wear-resistant powder; the conductive silver powder is promoted to make close contact with the interior of the bonding resin to form more conductive paths, the flexibility and printability of the silver paste are improved due to the existence of the plasticizer, the silver paste is more suitable for different application requirements, and the curing agent enhances the bonding strength and conductivity of the conductive silver paste by forming a stable net structure. Through the combined action of the two, the excellent performance of the conductive silver paste in various applications is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of conductive silver paste, and in particular to a conductive silver paste with high adhesion and low temperature curing and a preparation method thereof. Background Art

[0002] Low-temperature curing conductive silver paste is a key electronic material, widely used in the manufacture of electronic components such as membrane switches and printed circuit boards. The main features of this silver paste include low curing temperature, excellent conductivity, good adhesion and mechanical properties. However, if only adhesion promoter is added to the silver powder, the conductive network of the silver powder will be affected, thereby affecting the overall conductive performance. In addition, the silver powder particles cannot be well bonded, affecting the conductive path. Summary of the invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a high-adhesion, low-temperature curing conductive silver paste and a preparation method thereof.

[0004] In order to achieve the above object, the present invention adopts the following technical scheme: a high-adhesion low-temperature curing conductive silver paste, the composition and mass fraction of the conductive silver paste are:

[0005] Silver powder: 20-50 parts;

[0006] Polymer resin: 8-12 parts;

[0007] Curing agent: 1-3 parts;

[0008] Organic solvent: 20-40 parts;

[0009] Plasticizer: 1-3 parts;

[0010] Metal wear-resistant powder: 10-40 parts;

[0011] Adhesion promoter: 5-7 parts.

[0012] Furthermore, the silver powder is one of spherical silver powder, flaky silver powder and dendritic silver powder, and the average particle size of the silver powder is 3-5 μm.

[0013] Furthermore, the polymer resin is one of polyamide resin, acrylic resin, polyurethane and vinyl resin.

[0014] Furthermore, the curing agent is a resin curing agent, which is a phenolic resin or an amino resin.

[0015] Furthermore, the organic solvent is an ester solvent, and the ester solvent is one of ethyl acetate, butyl acetate, and ethyl lactate.

[0016] Furthermore, the plasticizer is one of diethyl oxalate, butyl ether and butyl phthalate.

[0017] Furthermore, the metal wear-resistant powder is silver-coated powder, and the particle size of the silver-coated powder is 2 μm to 4 μm.

[0018] Furthermore, the method for preparing the high-adhesion low-temperature curing conductive silver paste comprises the following steps:

[0019] S1: adding a corresponding amount of polymer resin according to the ratio to an organic solvent, stirring and mixing at a high speed at 60-85°C to completely dissolve the polymer resin, cooling to 30-50°C, and filtering with a 400-600 mesh cloth to obtain an organic carrier for use;

[0020] S2: Weigh corresponding amounts of silver powder and metal wear-resistant powder according to the proportion, mix them evenly using a high-speed mixer, and set aside;

[0021] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0022] S4: Weigh corresponding portions of curing agent, plasticizer and adhesion promoter according to the ratio, add them into the mixture of step S3, and use a three-roller mill to disperse them to a fineness of less than 12 μm to obtain a finished conductive silver paste.

[0023] Compared with the prior art, the advantages and positive effects of the present invention are:

[0024] In the present invention, by combining silver powder and metal wear-resistant powder, silver powder particles can be bonded together to form a good conductive path. By adding metal wear-resistant powder, wear resistance can be improved while maintaining low resistance. Then, a plasticizer and a curing agent are mixed. The network structure of the curing agent not only improves the bonding strength of the conductive silver paste, but also reduces the volume of the carrier bonding resin, so that the conductive silver powder is closely contacted inside the bonding resin to form more conductive paths. The presence of the plasticizer helps to improve the flexibility and printability of the silver paste, making it more suitable for different application requirements. The curing agent enhances the bonding strength and conductivity of the conductive silver paste by forming a stable network structure, and the plasticizer optimizes its printing performance and flexibility by adjusting the physical properties of the silver paste. The two work together to ensure the excellent performance of the conductive silver paste in various applications. DETAILED DESCRIPTION

[0025] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described below in conjunction with embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0026] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate the orientation or position relationship as shown, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0027] The present invention provides a high-adhesion, low-temperature curing conductive silver paste, the composition and mass fraction of the conductive silver paste are:

[0028] Silver powder: 20-50 parts;

[0029] Polymer resin: 8-12 parts;

[0030] Curing agent: 1-3 parts;

[0031] Organic solvent: 20-40 parts;

[0032] Plasticizer: 1-3 parts;

[0033] Metal wear-resistant powder: 10-40 parts;

[0034] Adhesion promoter: 5-7 parts.

[0035] In the present invention, the silver powder is one of spherical silver powder, flaky silver powder and dendritic silver powder, and the average particle size of the silver powder is 3-5 μm.

[0036] The polymer resin is one of polyamide resin, acrylic resin, polyurethane and vinyl resin.

[0037] The curing agent is a resin curing agent, which is a phenolic resin or an amino resin.

[0038] The organic solvent is an ester solvent, and the ester solvent is one of ethyl acetate, butyl acetate and ethyl lactate.

[0039] The plasticizer is one of diethyl oxalate, butyl ether and butyl phthalate.

[0040] The metal wear-resistant powder is silver-coated powder, and the particle size of the silver-coated powder is 2 μm to 4 μm.

[0041] The method for preparing a high-adhesion, low-temperature curing conductive silver paste comprises the following steps:

[0042] S1: adding a corresponding amount of polymer resin according to the ratio to an organic solvent, stirring and mixing at a high speed at 60-85°C to completely dissolve the polymer resin, cooling to 30-50°C, and filtering with a 400-600 mesh cloth to obtain an organic carrier for use;

[0043] S2: Weigh corresponding amounts of silver powder and metal wear-resistant powder according to the proportion, mix them evenly using a high-speed mixer, and set aside;

[0044] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0045] S4: Weigh corresponding portions of curing agent, plasticizer and adhesion promoter according to the ratio and add them into the mixture of step S3, and use a three-roller mill to disperse the mixture to a fineness of less than 12 μm to obtain a finished conductive silver paste.

[0046] Several embodiments are given below:

[0047] Embodiment 1

[0048] S1: Weigh 8 parts of polymer resin, add 20 parts of organic solvent, stir and mix at high speed at 60°C to make the polymer resin completely dissolved, cool to 30°C, and filter with a 400-mesh mesh to obtain an organic carrier for use;

[0049] S2: Weigh 40 parts of silver powder and 25 parts of metal wear-resistant powder, mix them evenly using a high-speed mixer, and set aside;

[0050] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0051] S4: Weigh 1 part of curing agent, 1 part of plasticizer and 5 parts of adhesion promoter, add them to the mixture of step S3, and use a three-roll mill to disperse them to a fineness of less than 12 μm to obtain a finished conductive silver paste.

[0052] Embodiment 2

[0053] S1: Weigh 8 parts of polymer resin, add 20 parts of organic solvent, stir and mix at high speed at 60°C to make the polymer resin completely dissolved, cool to 40°C, and filter with a 500-mesh mesh to obtain an organic carrier for use;

[0054] S2: Weigh 35 parts of silver powder and 25 parts of metal wear-resistant powder, mix them evenly using a high-speed mixer, and set aside;

[0055] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0056] S4: Weigh 3 parts of curing agent, 2 parts of plasticizer and 7 parts of adhesion promoter, add them to the mixture of step S3, and use a three-roll mill to disperse them to a fineness of less than 12 μm to obtain a finished conductive silver paste.

[0057] Embodiment 3

[0058] S1: Weigh 10 parts of polymer resin, add 20 parts of organic solvent, stir and mix at high speed at 60°C to make the polymer resin completely dissolved, cool to 50°C, and filter with a 600-mesh mesh to obtain an organic carrier for use;

[0059] S2: Weigh 45 parts of silver powder and 15 parts of metal wear-resistant powder, mix them evenly using a high-speed mixer, and set aside;

[0060] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0061] S4: Weigh 2 parts of curing agent, 3 parts of plasticizer and 5 parts of adhesion promoter, add them to the mixture of step S3, and use a three-roller mill to disperse them to a fineness of less than 12 μm to obtain a finished conductive silver paste.

[0062] Embodiment 4

[0063] S1: Weigh 12 parts of polymer resin, add 30 parts of organic solvent, stir and mix at high speed at 60°C to make the polymer resin completely dissolved, cool to 50°C, and filter with a 600-mesh mesh to obtain an organic carrier for use;

[0064] S2: Weigh 30 parts of silver powder and 17 parts of metal wear-resistant powder, mix them evenly using a high-speed mixer, and set aside;

[0065] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0066] S4: Weigh 3 parts of curing agent, 2 parts of plasticizer and 6 parts of adhesion promoter, add to the mixture of step S3, and use a three-roller mill to disperse to a fineness of less than 12 μm to obtain a finished conductive silver paste;

[0067] Embodiment 5

[0068] S1: Weigh 9 parts of polymer resin, add 40 parts of organic solvent, stir and mix at high speed at 75°C to make the polymer resin completely dissolved, cool to 50°C, and filter with a 550-mesh mesh to obtain an organic carrier for use;

[0069] S2: Weigh 23 parts of silver powder and 17 parts of metal wear-resistant powder, mix them evenly using a high-speed mixer, and set aside;

[0070] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0071] S4: Weigh 2 parts of curing agent, 2 parts of plasticizer and 7 parts of adhesion promoter, add them to the mixture of step S3, and use a three-roll mill to disperse them to a fineness of less than 12 μm to obtain a finished conductive silver paste.

[0072] Embodiment 6

[0073] S1: Weigh 12 parts of polymer resin, add 30 parts of organic solvent, stir and mix at high speed at 85°C to make the polymer resin completely dissolved, cool to 45°C, and filter with a 550-mesh mesh to obtain an organic carrier for use;

[0074] S2: Weigh 20 parts of silver powder and 26 parts of metal wear-resistant powder, mix them evenly using a high-speed mixer, and set aside;

[0075] S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture;

[0076] S4: Weigh 3 parts of curing agent, 3 parts of plasticizer and 6 parts of adhesion promoter, add them to the mixture of step S3, and use a three-roller mill to disperse them to a fineness of less than 12 μm to obtain a finished conductive silver paste.

[0077] Table 1

[0078]

[0079] It can be concluded from the above examples that the adhesion test result of the conductive paste prepared by the method of the present invention is that the adhesion is>14N / mm, and the effect is good.

[0080] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A high-adhesion, low-temperature curing conductive silver paste, characterized in that: The composition and mass fraction of the conductive silver paste are: Silver powder: 20-50 parts; Polymer resin: 8-12 parts; Curing agent: 1-3 parts; Organic solvent: 20-40 parts; Plasticizer: 1-3 parts; Metal wear-resistant powder: 10-40 parts; Adhesion promoter: 5-7 parts.

2. The high-adhesion, low-temperature curing conductive silver paste according to claim 1, characterized in that: The silver powder is one of spherical silver powder, flaky silver powder and dendritic silver powder, and the average particle size of the silver powder is 3-5 μm.

3. The high adhesion and low temperature curing conductive silver paste according to claim 1, characterized in that: The polymer resin is one of polyamide resin, acrylic resin, polyurethane and vinyl resin.

4. The high-adhesion, low-temperature curing conductive silver paste according to claim 1, characterized in that: The curing agent is a resin curing agent, which is a phenolic resin or an amino resin.

5. The high-adhesion, low-temperature curing conductive silver paste according to claim 1, characterized in that: The organic solvent is an ester solvent, and the ester solvent is one of ethyl acetate, butyl acetate and ethyl lactate.

6. The method for preparing the high-adhesion low-temperature curing conductive silver paste according to claim 1, characterized in that: The plasticizer is one of diethyl oxalate, butyl ether and butyl phthalate.

7. The method for preparing the high-adhesion low-temperature curing conductive silver paste according to claim 1, characterized in that: The metal wear-resistant powder is silver-coated powder, and the particle size of the silver-coated powder is 2 μm to 4 μm.

8. The method for preparing a high-adhesion, low-temperature curing conductive silver paste according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: adding a corresponding amount of polymer resin according to the ratio to an organic solvent, stirring and mixing at a high speed at 60-85°C to completely dissolve the polymer resin, cooling to 30-50°C, and filtering with a 400-600 mesh cloth to obtain an organic carrier for use; S2: Weigh corresponding amounts of silver powder and metal wear-resistant powder according to the proportion, mix them evenly using a high-speed mixer, and set aside; S3: adding the mixed silver powder and metal wear-resistant powder to the organic carrier in step S1, and mixing and dispersing them using a disperser to obtain a mixture; S4: Weigh corresponding portions of curing agent, plasticizer and adhesion promoter according to the ratio, add them into the mixture of step S3, and use a three-roller mill to disperse them to a fineness of less than 12 μm to obtain a finished conductive silver paste.

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