High-temperature-resistant conductive silver paste containing flaky silver powder and preparation method and application thereof

Abstract

The application discloses a high-temperature-resistant conductive silver paste containing flaky silver powder and a preparation method and application thereof. The application improves the conductivity and printing passability of the silver paste by mixing flaky silver powder into spherical silver powder. The application improves the high-temperature resistance and weather resistance of the silver paste by using phenolic epoxy resin as a bonding phase, so that the silver paste can be printed into a grid line with good linearity and small volume resistance, and can be used outdoors for a long time.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a high-temperature resistant conductive silver paste containing flake-shaped silver powder, its preparation method, and its application. Background Technology

[0002] Heterojunction solar cells utilize low-temperature curing silver paste. In the traditional production process, spherical silver powder is primarily used as the conductive phase. Due to the low curing temperature, the silver powder cannot directly sinter together and must rely on resin for bonding. This results in a relatively high amount of resin used, leading to higher resistivity and poor printability, thus reducing the overall efficiency of the cell. Furthermore, some resins have poor high-temperature resistance and weather resistance, limiting the use of heterojunction solar cells in various outdoor environments. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention propose a high-temperature resistant conductive silver paste containing flake-shaped silver powder, its preparation method, and its application.

[0005] In a first aspect, the present invention provides a high-temperature resistant conductive silver paste containing flake-shaped silver powder, comprising:

[0006] 85-90 parts by weight of conductive silver powder, wherein the conductive silver powder includes spherical silver powder and flake silver powder, and the proportion of flake silver powder is above 60 wt%.

[0007] 7-11 parts by weight of phenolic epoxy resin;

[0008] 3 to 6 parts by weight of solvent;

[0009] 4 to 7 parts by weight of additives;

[0010] 0.5–1.5 parts by weight of curing agent;

[0011] 0.5 to 1.5 parts by weight of anti-settling agent.

[0012] Furthermore, the particle size of the flake-shaped silver powder is 3–4 μm, and the tap density of the flake-shaped silver powder is 4–5 g / cm³. 3 .

[0013] Furthermore, the spherical silver powder has a particle size of 2–5 μm and a tap density of 3–5 g / cm³. 3 .

[0014] Furthermore, the phenolic epoxy resin includes one of phenolic epoxy resin or o-cresol epoxy resin.

[0015] Furthermore, the solvent includes one of ethyl acetate, ethylene glycol, dodecyl alcohol ester, and butylcarbitol.

[0016] Furthermore, the additives include one of methylimidazole, terpineol, and polyether.

[0017] Furthermore, the curing agent includes one of ethylenediamine, hexamethylenediamine, and maleic anhydride.

[0018] Furthermore, the anti-settling agent includes polyamide wax.

[0019] Secondly, the present invention provides a method for preparing the silver paste as described in the first aspect above, such as... Figure 1 As shown, it includes the following steps:

[0020] (1) Phenolic epoxy resin and solvent are mixed and stirred to obtain an organic carrier;

[0021] (2) The conductive silver powder, additives, curing agent, anti-settling agent and the organic carrier are mixed and stirred in an oil bath at 70-80°C, and then rolled to obtain conductive silver paste.

[0022] Thirdly, the present invention proposes the application of the silver paste proposed in the first aspect or the silver paste prepared by the method proposed in the second aspect above in heterojunction solar cells.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention improves the conductivity and printability of silver paste by incorporating flake silver powder into spherical silver powder; and improves the high temperature resistance and weather resistance of silver paste by using phenolic epoxy resin as a binder phase, enabling it to be printed into grid lines with good linearity and low volume resistance, and allowing for long-term outdoor use. Attached Figure Description

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0026] Figure 1 This is a flowchart of the method for preparing crystalline silicon solar cells according to the present invention. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0028] Example 1

[0029] (1) Seven parts of phenolic epoxy resin and six parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was phenolic epoxy resin and the solvent was ethyl acetate.

[0030] (2) 85 parts of conductive silver powder, 4 parts of additives, 0.5 parts of curing agent, 1.5 parts of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 60%, the additive is methylimidazole, the curing agent is hexamethylenediamine, and the anti-settling agent is polyamide wax.

[0031] Example 2

[0032] (1) Eight parts of phenolic epoxy resin and five parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was phenolic epoxy resin and the solvent was ethylene glycol.

[0033] (2) 90 parts of conductive silver powder, 7 parts of additives, 1.5 parts of curing agent, 0.5 parts of anti-settling agent, and the organic carrier are mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 90%, the additive is methylimidazole, the curing agent is ethylenediamine, and the anti-settling agent is polyamide wax.

[0034] Example 3

[0035] (1) Nine parts of phenolic epoxy resin and four parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was phenolic epoxy resin and the solvent was dodecyl alcohol ester.

[0036] (2) 86 parts of conductive silver powder, 6 parts of additives, 1 part of curing agent, 1.2 parts of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 80%, the additive is terpineol, the curing agent is maleic anhydride, and the anti-settling agent is polyamide wax.

[0037] Example 4

[0038] (1) 10 parts of phenolic epoxy resin and 3 parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was o-cresol epoxy resin and the solvent was butyl carbitol.

[0039] (2) 88 parts of conductive silver powder, 5 parts of additives, 1.2 parts of curing agent, 0.8 parts of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 70%, the additive is terpineol, the curing agent is hexamethylenediamine, and the anti-settling agent is polyamide wax.

[0040] Example 5

[0041] (1) 11 parts of phenolic epoxy resin and 5 parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was o-cresol epoxy resin and the solvent was butyl carbitol.

[0042] (2) 89 parts of conductive silver powder, 4 parts of additives, 0.8 parts of curing agent, 1 part of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 95%, the additive is methylimidazole, the curing agent is ethylenediamine, and the anti-settling agent is polyamide wax.

[0043] Comparative Example 1

[0044] (1) Seven parts of phenolic epoxy resin and six parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was phenolic epoxy resin and the solvent was ethyl acetate.

[0045] (2) 85 parts of conductive silver powder, 4 parts of additives, 0.5 parts of curing agent, 1.5 parts of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in the conductive silver powder was 0, the additive was methylimidazole, the curing agent was hexamethylenediamine, and the anti-settling agent was polyamide wax.

[0046] Comparative Example 2

[0047] (1) Seven parts of phenolic epoxy resin and six parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was phenolic epoxy resin and the solvent was ethyl acetate.

[0048] (2) 85 parts of conductive silver powder, 4 parts of additives, 0.5 parts of curing agent, 1.5 parts of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 10%, the additive is methylimidazole, the curing agent is hexamethylenediamine, and the anti-settling agent is polyamide wax.

[0049] Comparative Example 3

[0050] (1) Seven parts of phenolic epoxy resin and six parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was phenolic epoxy resin and the solvent was ethyl acetate.

[0051] (2) 85 parts of conductive silver powder, 4 parts of additives, 0.5 parts of curing agent, 1.5 parts of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 20%, the additive is methylimidazole, the curing agent is hexamethylenediamine, and the anti-settling agent is polyamide wax.

[0052] Comparative Example 4

[0053] (1) Seven parts of phenolic epoxy resin and six parts of solvent were stirred and mixed at 400 r / min for 30 min to obtain an organic carrier. Among them, the phenolic epoxy resin was phenolic epoxy resin and the solvent was ethyl acetate.

[0054] (2) 85 parts of conductive silver powder, 4 parts of additives, 0.5 parts of curing agent, 1.5 parts of anti-settling agent, and the organic carrier were mixed and stirred at 500 r / min for 8 h in an oil bath at 70℃, and then rolled to obtain conductive silver paste. Among them, the mass ratio of flake silver powder in conductive silver powder is 30%, the additive is methylimidazole, the curing agent is hexamethylenediamine, and the anti-settling agent is polyamide wax.

[0055] Experimental Example 1

[0056] The resistivity of the conductive silver pastes prepared in Examples 1 to 5 (i.e., Comparative Examples 1 to 4) was tested, and the test results are shown in Table 1 below.

[0057] Table 1:

[0058] Grouping Resistivity (Ω·m) Example 1 <![CDATA[6.9×10 -8 ]]> Example 2 <![CDATA[7.3×10 -8 <!-- 3 -->]]> Example 3 <![CDATA[7.6×10 -8 ]]> Example 4 <![CDATA[7.0×10 -8 ]]> Example 5 <![CDATA[6.5×10 -8 ]]> Comparative Example 1 <![CDATA[8.9×10 -8 ]]> Comparative Example 2 <![CDATA[8.0×10 -8 ]]> Comparative Example 3 <![CDATA[8.6×10 -8 ]]> Comparative Example 4 <![CDATA[8.3×10 -8 ]]>

[0059] As shown in Table 1, compared with the examples, the conductivity of the silver paste was relatively low when no flake silver powder was added or the amount of flake silver powder added was small in Comparative Examples 1 to 4.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms may refer to different embodiments or examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A high-temperature resistant conductive silver paste containing flake-shaped silver powder, characterized in that, include: 85-90 parts by weight of conductive silver powder, wherein the conductive silver powder includes spherical silver powder and flake silver powder, and the proportion of flake silver powder is above 60 wt%. 7-11 parts by weight of phenolic epoxy resin; 3 to 6 parts by weight of solvent; 4 to 7 parts by weight of additives; 0.5–1.5 parts by weight of curing agent; 0.5 to 1.5 parts by weight of anti-settling agent.

2. The conductive silver paste as described in claim 1, characterized in that, The flake-shaped silver powder has a particle size of 3–4 μm and a tap density of 4–5 g / cm³. 3 .

3. The conductive silver paste as described in claim 1, characterized in that, The spherical silver powder has a particle size of 2–5 μm and a tap density of 3–5 g / cm³. 3 .

4. The conductive silver paste as described in claim 1, characterized in that, The phenolic epoxy resin includes either phenolic epoxy resin or o-cresol epoxy resin.

5. The conductive silver paste as described in claim 1, characterized in that, The solvent includes one of ethyl acetate, ethylene glycol, dodecyl alcohol ester, and butylcarbitol.

6. The conductive silver paste as described in claim 1, characterized in that, The additives include one of methylimidazole, terpineol, and polyether.

7. The conductive silver paste as described in claim 1, characterized in that, The curing agent includes one of ethylenediamine, hexamethylenediamine, and maleic anhydride.

8. The conductive silver paste as described in claim 1, characterized in that, The anti-settling agent includes polyamide wax.

9. A method for preparing conductive silver paste, characterized in that, The preparation of the conductive silver paste according to any one of claims 1 to 8 includes the following steps: (1) A phenolic epoxy resin and a solvent are mixed and stirred to obtain an organic carrier; (2) The conductive silver powder, additives, curing agent, anti-settling agent and the organic carrier are mixed and stirred in an oil bath at 70-80°C, and then rolled to obtain conductive silver paste.

10. The conductive silver paste according to claims 1 to 8 or the conductive silver paste prepared by the method according to claim 9 is used in the fabrication process of heterojunction solar cells.

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