Preparation method of sea urchin-shaped silver powder for thin-film solar cell silver paste

Abstract

The invention relates to the technical field of electronic paste, in particular to a preparation method of sea urchin-shaped silver powder for thin-film solar cell silver paste. The preparation method comprises the following steps: preparing zinc oxide powder with sea urchin-shaped morphology through zinc acetate, ammonia water, sodium borohydride and PVP, and dispersing sea urchin-shaped zinc oxide powder particles serving as an inner core into a stannous chloride aqueous solution; and then performing filtering, adding particles into a silver-triethanolamine solution, further soaking sea urchin-shaped zinc oxide particles with the surfaces covered with nano-silver seed crystals into the silver-triethanolamine solution, and performing reduction through a formaldehyde solution, so that more elemental silver covers the inner cores of the sea urchin-shaped zinc oxide particles, and sea urchin-shaped silver-zinc composite particles are formed. The obtained particles have sea urchin-shaped structures and are not easy to agglomerate in paste preparation and dispersion processes, and spines on the surfaces of the particles are connected in a paste sintering process to further form a conductive grid, so that the conductivity of a membrane material can be effectively improved, the use quantity of noble metals is relatively small, and the cost of raw materials can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of electronic paste, in particular to a method for preparing sea urchin-shaped silver powder used for thin-film solar cell silver paste. Background technique [0002] With the rapid development of microelectronics technology, electronic devices are increasingly developing in the direction of miniaturization, integration and high frequency. Electronic paste is a mixed system of solid particles and organic liquids composed of functional fillers, inorganic fillers and polymer binders suspended in organic carriers. This fluid material is applied to electronic components through printing and other methods to form modules with specific electrical functions. It is the basic material for various electronic components such as integrated circuits, chip components, photovoltaic devices, flexible batteries, and transistors. Conductive silver paste is one of the key core technologies of thin-film solar cells. It plays a...

AI Technical Summary

Problems solved by technology

However, the price of precious metals is high, which is extremely unfavorable to the production cost of electronic paste. At present, most of the precious metal conductive fillers on the market use silver powder, and in the environment where the conductivity is not high, base metals such as copper, nickel, aluminum, etc. are used. replace

[0004] For the production of electronic paste, the cost of the noble metal conductive phase is the bulk of the electronic paste, which is very unfavorable for the compression of production costs. Patent CN103559940A proposes a copper-based electronic paste and its preparation method and application, using copper powder Copper is used as raw material to prepare oil-based or water-based electronic paste, which uses copper as the conductive phase instead of precious metals, but copper has high activity and the surface is easily oxidized, which makes it difficult to control the process of sintering process, and the conductive effect of the formed film is not enough ideal

Patent CN104078096A proposes a low-cost printed circuit board silver paste and its preparation method, which is made of the following raw materials in parts by weight: 0.5-2μm silver powder 36-45, nano aluminum powder 5-8, 20-40nm silver powder 10-20, Tin dioxide conductive ceramic powder 4-7, lecithin 2-4, nanocrystalline cellulose 1-2, dry alkyd resin 14-17, 1-10μm flake graphite powder 3-6, amyl acetate 1-3, Alcohol ester dodeca 0.2-0.4, glass powder 6-8, xylene 6-8, isophorone 8-10, isoamyl acetate 1-2, ethylene glycol monobutyl ether 2-4, which will be oxidized by Tin, nano-aluminum powder and silver powder are mixed as fillers to reduce the amount of silver powder. However, this simple mixing process has a great impact on the effect of the formed conductive film, and it is difficult to effectively apply to environments with high conductivity requirements.

Patent CN102950283B proposes a preparation method of ultra-fine silver-plated copper powder for electronic paste. The preparation steps include: (1) taking super-fine copper powder for surface treatment as copper powder to be plated; (2) mixing dispersant, additive, The reducing agent is added to deionized water, and the copper powder to be plated is added, and the pH value is adjusted to 12-14 to obtain the mixture to be plated; (3) silver nitrate is added to deionized water and an amine complexing agent to obtain a silver amine solution; (4 ) adding the silver amine solution to the mixture to be plated to obtain silver-plated copper powder; (5) cleaning the silver-plated copper powder with deionized water as the copper powder to be plated, and entering steps (2) to (4) silver plating cycle again , to obtain secondary silver-plated copper powder; (6) secondary silver-plated copper powder is placed in an organic solution, suction filtered, dehydrated, and superfine silver-plated copper powder is obtained after drying. Although the cost can be effectively reduced, this method obtains The silver-plated copper powder has poor dispersion in electronic paste and has reduced conductivity

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