HJT low-temperature conductive silver paste and preparation method thereof

Abstract

The invention provides HJT low-temperature conductive silver paste and a preparation method thereof. The low-temperature conductive silver paste comprises the following raw material components in parts by weight: 2-5 parts of polyurethane resin, 1-3 parts of epoxy resin, 2.5-4 parts of a solvent, 0.2-0.5 part of a curing agent, 0.5-1.5 parts of an additive and 86-95 parts of silver powder, the silver powder comprises micron powder and nano powder; the preparation method comprises the following steps: (1) mixing organic phase raw materials, and carrying out first dispersion to obtain a resin liquid; (2) mixing the resin liquid and nano powder, and sequentially carrying out second dispersion, ultrasonic dispersion and third dispersion to obtain a nano powder solution; (3) mixing the nano powder solution and the class A micron powder, and performing first rolling to obtain semi-finished silver paste; and (4) mixing the semi-finished product silver paste, the class B micron powder and the additive, and carrying out second rolling and fourth dispersion to obtain the low-temperature conductive silver paste, according to the preparation method, the silver powder with different particle sizes is added step by step, so that the bonding strength and uniformity of the silver paste are improved, and the electrical property and the printing property of the low-temperature conductive silver paste are improved.

Description

technical field [0001] The invention belongs to the technical field of conductive materials, and in particular relates to a low-temperature conductive silver paste of HJT and a preparation method thereof. Background technique [0002] In the past two decades, electronic science and technology have developed rapidly. As an important part, low-temperature curing conductive silver paste has been widely used in solar cells, membrane switches, RFID, flexible printed circuit boards and many other fields through screen printing technology. Solar cells are considered to be one of the most promising new energy technologies in the future due to their many advantages such as cleanness and environmental protection, wide application range, simple operation, stable operation, abundant material sources, and long service life. [0003] Low-temperature curing silver paste is an important part of the photovoltaic solar industry, which is mainly composed of conductive functional phase, matrix ...

AI Technical Summary

Problems solved by technology

The conductive silver paste pretreats the silver powder to obtain better properties, but the silver powder obtained by the method needs to be dried, and the process is relatively complicated

[0005] CN111261320A discloses an epoxy resin-based low-temperature conductive silver paste and a preparation method thereof, comprising the following components by weight: 55-75 parts by weight of silver powder, 5-15 parts by weight of epoxy resin, 0.3-10 parts by weight of curing agent, 0.05-5 parts by weight of curing accelerator, 2-18 parts by weight of diluent, 0.011 parts by weight of inhibitor, 0.1-3 parts by weight of rheology additive, and 0.5-5 parts by weight of additives, with lower curing temperature and smaller Viscosity, suitable for screen printing process; but single diameter silver powder makes the conductive silver paste easy to peel off

[0006] CN113345623A discloses a HJT battery low-temperature curing silver paste for fine printing and a preparation method thereof. The HJT battery low-temperature curing silver paste is calculated in parts by weight, and the composition of raw materials includes: 88-93 parts of main conductive silver powder, 0.2- 5 parts of auxiliary conductive silver powder, 2.5-9 parts of main epoxy resin, 0.1-2 parts of low-viscosity epoxy resin, 0.1-0.5 parts of curing agent, and 2-5 parts of organic solvent. HJT battery low-temperature curing silver for fine printing The introduction of low-viscosity epoxy resin in the paste is beneficial to improve the cohesion between the main epoxy resin of the HJT battery low-temperature curing silver paste, and between the main epoxy resin and the main conductive silver powder, and optimize the viscosity and rheological properties of the low-temperature curing silver paste of the HJT battery , reduce the mesh resistance, thereby increasing the printing speed of HJT battery low-temperature curing silver paste, and increasing the production capacity of HJT batteries; the combination of flake silver powder and micron-sized spherical silver powder is used to obtain low-temperature curing silver for HJT batteries with better bonding force and conductivity paste, but the silver paste adopts flake silver powder, so the fluidity is not enough to be used in the finer grid positive silver electrode

[0007] At present, most literatures and patents only generally use the method of mixing organic and silver powder to prepare silver paste, and do not fully consider the order of adding different organic substances and different silver powders. Infiltration, adsorption, lubrication and other functions; and the silver powder is also scattered accumulation, disorderly filling

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