Silver paste composition for laser engraving touch screen and preparation method thereof

Abstract

The invention provides a silver paste composition for laser engraving of a touch screen and a preparation method thereof.The silver paste composition for laser engraving of the touch screen comprises silver powder A, silver powder B, a carrier and auxiliaries, the silver powder A is nanoscale silver powder, the silver powder B is submicron silver powder, the carrier comprises resin, and the auxiliaries are added into the carrier. The resin comprises at least one of polyester resin, polyurethane resin, acrylic resin, phenolic resin and phenolic modified resin. The invention aims to improve the adhesive force of the silver paste so as to be suitable for a gradually refined laser engraving technology.

Description

Technical Field

[0001] The invention relates to the technical field of silver paste preparation, in particular to a silver paste composition for laser engraving a touch screen and a preparation method thereof. Background Art

[0002] The communication field is developing rapidly, the market demand for mobile phone modules is increasingly promising, and the market competition is fierce. The touch screen module business is more sophisticated, and the yield rate requirements are getting higher and higher, which leads to higher and higher requirements for touch screen silver paste; At present, the silver paste for touch screens in the market adopts two processes: printing and laser engraving. The specifications of laser engraved silver paste are getting smaller and smaller, from the original 100μm / 100μm to the current 20μm / 20μm or even smaller specifications. Conventional touch screen silver paste engraving 20μm / 20μm has broken and connected lines after laser engraving, and the adhesion after laser engraving decreases, resulting in a decrease in product yield. At present, there are not many high-quality pastes of 20μm / 20μm and below in China. At present, imported pastes are still the main ones, and breaking the market monopoly of foreign pastes needs to be solved urgently. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a silver paste composition for laser engraving touch screen, aiming to improve the adhesion of the silver paste so as to be suitable for the increasingly sophisticated laser engraving technology.

[0004] The invention provides a silver paste composition for a laser engraving touch screen, comprising silver powder A, silver powder B, a carrier and an auxiliary agent, wherein the silver powder A is nanometer-grade silver powder, the silver powder B is submicron-grade silver powder, and the carrier comprises a resin, wherein the resin comprises at least one of a polyester resin, a polyurethane resin, an acrylic resin, a phenolic resin and a phenolic modified resin.

[0005] In one embodiment, the B silver powder includes flaky silver powder and spherical silver powder with a particle size of 0.2-0.6 μm.

[0006] In one embodiment, according to the weight parts: 5-10 parts of A silver powder; 50-60 parts of B silver powder; 20-30 parts of carrier; 0.5-3.5 parts of auxiliary agent.

[0007] In one embodiment, the auxiliary agent includes at least one of a silane coupling agent, a dispersant, an anti-settling agent and a leveling agent.

[0008] In one embodiment, the dispersant accounts for 10%-30% of the auxiliary agent, and the leveling agent accounts for 10%-30% of the auxiliary agent.

[0009] The present invention also provides a method for preparing the silver paste composition for laser engraving touch screen as described above, the preparation step comprising preparing the carrier, and then uniformly mixing the carrier, the A silver powder, the B silver powder and the auxiliary agent to obtain the silver paste composition for laser engraving touch screen.

[0010] In one embodiment, the specific step of preparing the carrier includes mixing the resin and the solvent and then dissolving them at 80°C.

[0011] In one embodiment, the ratio of the solvent to the carrier is 65%-98%.

[0012] In one embodiment, the solvent includes at least one of butyl acetate, DBE and dibutyl acetate.

[0013] In one embodiment, the preparing step further comprises grinding the mixed components to an average fineness of less than 5 μm.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) By using submicron-scale flaky silver powder, the system resistance can be effectively reduced, a good conductive path can be formed, and a good connection between silver particles can be promoted; adding nano-scale silver powder can effectively fill the gaps between the flaky silver powders, which can further reduce the system resistance and prevent defects such as broken wires, effectively solving the problem of hollowing out after engraving and baking.

[0015] (2) The resins selected in the present invention are determined based on the properties of the ITO film material, aiming to improve the adhesion of the silver paste to the ITO film material.

[0016] (3) The resin in the present invention has a high Tg value and can assist in laser engraving a touch screen to obtain a laser effect.

[0017] (4) The combination of spherical powder and flaky silver powder / nano silver powder can effectively reduce the slurry resistance and ensure a good laser engraving effect, and can achieve a 25 / 25μm laser process. Implementation

[0018] The specific embodiments of the present invention are described in detail below. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the description of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] The terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of the elements listed and may also include additional elements not expressly listed.

[0020] It is worth mentioning that the present invention only lists a number of representative specific implementations, which is intended to reflect the beneficial effects of the present invention, and is not equivalent to the implementations shown below being all implementations of the present invention. Example 1

[0021] The invention provides a silver paste composition for a laser engraving touch screen, comprising 7 parts of silver powder A, 55 parts of silver powder B, 25 parts of a carrier and 2 parts of an auxiliary agent, wherein the silver powder A is nanometer-grade silver powder, and the silver powder B is a mixture of flaky silver powder and spherical silver powder with a particle size of 0.2-0.6 μm; the carrier comprises a resin and a solvent, the resin is a polyester resin, and the solvent is ethylene glycol butyl ether acetate accounting for 80% of the volume of the carrier; the auxiliary agent is a silane coupling agent, a dispersant, an anti-settling agent and a leveling agent; the dispersant accounts for 20% of the auxiliary agent, and the leveling agent accounts for 20% of the auxiliary agent. Example 2

[0022] This embodiment provides a silver paste composition, which is different from Embodiment 1 in that A silver powder is 5 parts; B silver powder is 60 parts; the resin is polyurethane resin, and the solvent is diethylene glycol butyl ether acetate accounting for 98% of the carrier volume. Example 3

[0023] This embodiment provides a silver paste composition, which is different from Embodiment 1 in that A silver powder is 10 parts; B silver powder is 50 parts; the resin is an acrylic resin, and the solvent is DBE which accounts for 65% of the carrier volume. Example 4

[0024] This embodiment provides a silver paste composition, which is different from Embodiment 1 in that A silver powder is 8 parts; B silver powder is 57 parts; the resin is phenolic resin, and the solvent is ethylene glycol butyl ether acetate accounting for 85% of the carrier volume.

[0025] Comparative Example 1 This comparative example provides a silver paste composition, which is different from Example 1 in that no silver powder A is added, and silver powder B is 62 parts of flaky silver powder with a diameter of 0.2-0.6 μm.

[0026] Comparative Example 2 This comparative example provides a silver paste composition, which is different from Example 1 in that the resin is an epoxy resin.

[0027] Preparation Example 1 This preparation example provides a method for preparing a silver paste composition. According to the components and proportions of the silver paste composition in Example 1, a solvent and a resin are mixed and heated to dissolve to prepare a carrier. Then the carrier, silver powder A, silver powder B and an auxiliary agent are evenly mixed to obtain a silver paste.

[0028] Preparation Example 2 This preparation example provides a method for preparing a silver paste composition. According to the components and proportions in the silver paste composition of Example 2, a solvent and a resin are mixed and heated to dissolve to prepare a carrier. Then the carrier, silver powder A, silver powder B and an auxiliary agent are evenly mixed to obtain a silver paste.

[0029] Preparation Example 3 This preparation example provides a method for preparing a silver paste composition. According to the components and proportions in the silver paste composition of Example 3, a solvent and a resin are mixed and heated to dissolve to prepare a carrier. Then the carrier, silver powder A, silver powder B and an auxiliary agent are evenly mixed to obtain a silver paste.

[0030] Preparation Example 4 This preparation example provides a method for preparing a silver paste composition. According to the components and proportions in the silver paste composition of Comparative Example 1, a solvent and a resin are mixed and heated to dissolve to prepare a carrier, and then the carrier, B silver powder and an auxiliary agent are evenly mixed to obtain a silver paste.

[0031] Preparation Example 5 This preparation example provides a method for preparing a silver paste composition. According to the components and proportions in the silver paste composition of Comparative Example 2, a solvent and a resin are mixed and heated to dissolve to prepare a carrier. Then the carrier, silver powder A, silver powder B and an additive are evenly mixed to obtain a silver paste.

[0032] Performance Testing The silver pastes obtained in Preparation Examples 1 to 5 were subjected to tensile tests, and the results are shown in Table 1: Table 1 Test items Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5 Average tension / N 26 25 25 20 22 Please refer to the data in Table 1 above. The adhesion (tensile force) of Preparation Examples 1 to 3 is better, while the silver paste in Preparation Example 4 uses a single silver powder, and the adhesion is reduced. The resin used in the silver paste in Preparation Example 5 is less effective in improving adhesion than the resin of the silver paste in Preparation Example 1.

[0033] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A silver paste composition for laser engraving touch screen, It is characterized in that The invention comprises silver powder A, silver powder B, a carrier and an auxiliary agent, wherein the silver powder A is nano silver powder, the silver powder B is submicron silver powder, the carrier comprises resin, and the resin comprises at least one of polyester resin, polyurethane resin, acrylic resin, phenolic resin and phenolic modified resin.

2. The silver paste composition for laser engraving touch screen according to claim 1, It is characterized in that The B silver powder includes flaky silver powder and spherical silver powder with a particle size of 0.2-0.6 μm.

3. The silver paste composition for laser engraving touch screen according to claim 1, It is characterized in that According to weight parts: A silver powder 5-10 parts; B silver powder 50-60 parts; 20-30 copies of carrier; Additives 0.5-3.5 parts.

4. The silver paste composition for laser engraving touch screen according to claim 1, It is characterized in that The auxiliary agent includes at least one of a silane coupling agent, a dispersant, an anti-settling agent and a leveling agent.

5. The silver paste composition for laser engraving touch screen according to claim 1, It is characterized in that The dispersant accounts for 10%-30% of the auxiliary agent, and the leveling agent accounts for 10%-30% of the auxiliary agent.

6. A method for preparing a silver paste composition for laser engraving a touch screen according to any one of claims 1 to 5, It is characterized in that The preparation step comprises preparing the carrier, and then uniformly mixing the carrier, the A silver powder, the B silver powder and the auxiliary agent to obtain the silver paste composition for laser engraving touch screen.

7. The method for preparing the silver paste composition for laser engraving touch screen according to claim 6, It is characterized in that The specific steps of preparing the carrier include mixing the resin and the solvent and then dissolving them at 80°C.

8. The method for preparing the silver paste composition for laser engraving touch screen according to claim 7, It is characterized in that The ratio of the solvent to the carrier is 65%-98%.

9. The method for preparing the silver paste composition for laser engraving touch screen according to claim 6, It is characterized in that The solvent includes at least one of ethylene glycol butyl ether acetate, DBE and diethylene glycol butyl ether acetate.

10. The method for preparing the silver paste composition for laser engraving touch screen according to claim 6, It is characterized in that The preparation step further comprises grinding the mixed components to an average fineness of less than 5 μm.