阅读说明：本技术 一种银粉复合导电银浆及其制作方法 (Silver powder composite conductive silver paste and manufacturing method thereof ) 是由 张智萍 袁海峰 张俊元 郭丹 于 2020-12-17 设计创作，主要内容包括：本发明公开了一种银粉复合导电银浆,包括如下组分：球形银粉50-60份；三氟甲烷磺酸银10-15份；二乙基二硫代氨基甲酸银10-15份；分散剂5-10份；表面活性剂5-10份；所述球形银粉为纳米级银粉；其中随着温度的升高,金属有机化合物发生分解,随之有银颗粒的产生,这些新析出的银増加了银浆中原有银颗粒的连接网络,从而增加了导热导电性能；球形银粉采用纳米级银粉,其具有更大表比能,单位比表面能高,银浆在固化过程中能增加了烧结驱动力,同时在制备时,通过超声波研磨设备(即通过超声振荡重新分散)可将团聚在一起的颗粒重新分散开来,解决了银粉颗粒因团聚导致颗粒不均匀分散,形成空洞的问题。(The invention discloses silver powder composite conductive silver paste which comprises the following components: 50-60 parts of spherical silver powder; 10-15 parts of silver trifluoromethanesulfonate; 10-15 parts of silver diethyldithiocarbamate; 5-10 parts of a dispersing agent; 5-10 parts of a surfactant; the spherical silver powder is nano-scale silver powder; with the increase of the temperature, the metal organic compound is decomposed, silver particles are generated, and the newly precipitated silver increases the connecting network of the original silver particles in the silver paste, so that the heat conduction and electric conduction performance are increased; the spherical silver powder adopts the nano-scale silver powder, the specific surface energy of the nano-scale silver powder is higher, the sintering driving force can be increased in the solidification process of the silver paste, and meanwhile, during preparation, the particles which are agglomerated together can be re-dispersed through ultrasonic grinding equipment (namely, the particles are re-dispersed through ultrasonic oscillation), so that the problem that the particles of the silver powder are non-uniformly dispersed to form cavities due to agglomeration is solved.)

1. The silver powder composite conductive silver paste is characterized in that: comprises the following components in parts by weight:

50-60 parts of spherical silver powder;

10-15 parts of silver trifluoromethanesulfonate;

10-15 parts of silver diethyldithiocarbamate;

5-10 parts of a dispersing agent;

5-10 parts of a surfactant;

the spherical silver powder is nano-scale silver powder.

2. The silver powder composite conductive silver paste according to claim 1, which is characterized in that: the D50 of the nano-scale silver powder is 20-50nm, and the tap density is 6-8 g/mL.

3. The silver powder composite conductive silver paste according to claim 1, which is characterized in that: the silver powder composite conductive silver paste also comprises 2-5 parts by weight of magnesium oxide powder, and the magnesium oxide powder is filled in the polyimide adhesive.

4. The silver powder composite conductive silver paste according to claim 1, which is characterized in that: the dispersing agent is one or more of triethyl hexyl phosphoric acid, sodium dodecyl sulfate and methyl amyl alcohol.

5. The silver powder composite conductive silver paste according to claim 1, which is characterized in that: the surfactant is one or more of fatty glyceride, fatty alcohol ester and long-chain fatty acid ester.

6. The manufacturing method of the silver powder composite conductive silver paste is characterized by comprising the following steps of: the method comprises the following steps:

step one, conductive phase configuration: putting the spherical silver powder and the dispersing agent into ultrasonic mixing and stirring equipment together, and uniformly stirring and mixing the spherical silver powder and the dispersing agent to obtain a material A;

adding silver trifluoromethanesulfonate and silver diethyldithiocarbamate into a dispersing agent together, and mixing and stirring uniformly to obtain a material B;

step three, production of silver paste: and putting the material A and the material B into ultrasonic grinding equipment together for grinding for 1-2h to obtain the silver powder composite conductive silver paste.

7. The method for preparing silver powder composite conductive silver paste according to claim 6, wherein the method comprises the following steps: after the silver powder composite conductive silver paste is prepared, a viscosity regulator is added into the silver powder composite conductive silver paste and stirred, so that the viscosity of the silver powder composite conductive silver paste is controlled to be 800 plus and 1200Pa and seeds.

Technical Field

The invention relates to the field of conductive silver paste, in particular to silver powder composite conductive silver paste and a manufacturing method thereof.

Background

Conductive silver paste is mainly classified into two types: one is polymer silver conductive paste (dried or solidified into a film, and organic polymer is used as a bonding phase); the other is sintered silver conductive paste (sintering film, sintering temperature >500 ℃, glass powder or oxide as binding phase).

At present, when the conductive silver paste is applied to a silicon wafer for solar power generation, the conductive silver paste is generally coated on the silicon wafer in a screen printing mode, and then the front electrode is manufactured through a rapid sintering process, so that the change condition of the silver powder in the sintering process of the conductive silver paste affects the microstructure of a formed silver film and the conductivity of the silver film and the connection performance of the silver film and a silicon substrate.

However, the long-term use results show that the surface quality of the existing conductive silver paste is relatively unstable after sintering and curing, particles are not uniformly dispersed, and a void phenomenon is easy to occur, so that the sheet resistance of a silver film is increased.

Therefore, how to solve the defects of the prior art is a subject of the present invention.

Disclosure of Invention

In order to solve the problems, the invention discloses silver powder composite conductive silver paste and a manufacturing method thereof.

In order to achieve the above purpose, the invention provides the following technical scheme: the silver powder composite conductive silver paste comprises the following components in parts by weight:

50-60 parts of spherical silver powder;

10-15 parts of silver trifluoromethanesulfonate;

10-15 parts of silver diethyldithiocarbamate;

5-10 parts of a dispersing agent;

5-10 parts of a surfactant;

the spherical silver powder is nano-scale silver powder.

As an improvement of the invention, the spherical silver powder is nano-scale silver powder, the D50 of the nano-scale silver powder is 20-50nm, and the tap density is 6-8 g/mL.

As an improvement of the invention, the silver powder composite conductive silver paste further comprises magnesium oxide powder, wherein the magnesium oxide powder accounts for 2-5 parts by weight, and the magnesium oxide powder is filled in the polyimide adhesive.

As a modification of the invention, the dispersant is one or more of triethylhexyl phosphoric acid, sodium dodecyl sulfate and methyl amyl alcohol.

As a modification of the invention, the surfactant is one or more of fatty glyceride, fatty alcohol ester and long-chain fatty acid ester.

The preparation method of the silver powder composite conductive silver paste comprises the following steps:

step one, conductive phase configuration: putting the spherical silver powder and the dispersing agent into ultrasonic mixing and stirring equipment together, and uniformly stirring and mixing the spherical silver powder and the dispersing agent to obtain a material A;

adding silver trifluoromethanesulfonate and silver diethyldithiocarbamate into a dispersing agent together, and mixing and stirring uniformly to obtain a material B;

step three, production of silver paste: and putting the material A and the material B into ultrasonic grinding equipment together for grinding for 1-2h to obtain the silver powder composite conductive silver paste.

As an improvement of the invention, after the silver powder composite conductive silver paste is prepared, a viscosity regulator is added into the silver powder composite conductive silver paste and stirred, so that the viscosity is controlled to be 800-1200Pa and seeds.

Compared with the prior art, the invention has the following advantages: according to the conductive silver paste, the silver diethyldithiocarbamate, the silver trifluoromethanesulfonate and the spherical silver powder are used as main conductive phases, wherein metal organic compounds are decomposed along with the increase of temperature, so that silver particles are generated, and the newly separated silver increases the connecting network of the original silver particles in the silver paste, so that the heat conduction and conductivity are improved; the spherical silver powder adopts the nano-scale silver powder, the specific surface energy of the nano-scale silver powder is higher, the sintering driving force can be increased in the solidification process of the silver paste, and meanwhile, during preparation, the particles which are agglomerated together can be re-dispersed through ultrasonic grinding equipment (namely, the particles are re-dispersed through ultrasonic oscillation), so that the problem that the particles of the silver powder are non-uniformly dispersed to form cavities due to agglomeration is solved.

Description of the invention

FIG. 1 is a graph showing the sheet resistance test results of the sintered silver film of example 3.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and is therefore not to be construed as limiting the invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

The preparation method of the conductive silver paste in the following embodiment is as follows:

step one, conductive phase configuration: putting the spherical silver powder and the dispersing agent into ultrasonic mixing and stirring equipment together, and uniformly stirring and mixing the spherical silver powder and the dispersing agent to obtain a material A;

adding silver trifluoromethanesulfonate and silver diethyldithiocarbamate into a dispersing agent together, and mixing and stirring uniformly to obtain a material B;

step three, production of silver paste: putting the material A and the material B into ultrasonic grinding equipment together for grinding for 1-2h to obtain the silver powder composite conductive silver paste;

after the silver powder composite conductive silver paste is prepared, a viscosity regulator is added into the silver powder composite conductive silver paste and stirred, so that the viscosity of the silver powder composite conductive silver paste is controlled to be 800 plus and 1200Pa and seeds.

Examples 1 to 3 and comparative examples 1 to 2:

in table 1, examples 1, 2 and 3 are ratios of conductive silver pastes prepared by using different parts by weight of raw materials to cause a void phenomenon after sintering and curing 1000 parts of the product, wherein the difference between comparative example 1 and example 3 is that the conductive phase in comparative example 1 is not added with silver trifluoromethanesulfonate and silver diethyldithiocarbamate;

TABLE 1

From the results in table 1, it can be seen that the conductive silver pastes prepared in examples 1 to 3 of the present invention have a greatly reduced occurrence of voids during the sintering process.

FIG. 1 shows that the sheet resistance of the sintered silver film of example 3 was measured by a ST-2258C model multifunction four-point probe tester, and the sheet resistance was reduced to 2.83. omega. □ -1 after heat treatment at 600 ℃ for 60 min.

The technical means disclosed in the invention scheme are not limited to the technical means disclosed in the above embodiments, but also include the technical scheme formed by any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and such improvements and modifications are also considered to be within the scope of the present invention.