Pressureless sintered copper paste and manufacturing method thereof

Abstract

This invention relates to a pressureless sintering copper adhesive and its manufacturing method. The method mainly involves uniformly mixing sintering aids, organic matter, and copper powder to form a pressureless sintering copper adhesive. When sintering is performed under no pressure, the sintering aids and organic matter will decompose and volatilize during the sintering process, allowing nano-sized copper particles to fully fill the gaps between micron-sized copper particles. This improves the tightness and reliability of the copper particle bonding, thereby solidifying to form a sintered body with a stable and dense structure and good mechanical properties.

Claims

1. A method for manufacturing pressureless sintered copper adhesive, the implementation steps of which include: A. Preparing sintering aids: the sintering aids are selected from one or more combinations of copper amine complexes, copper carboxylic acid complexes, copper oxalic acid complexes, copper-amine-carboxylic acid co-complexes, copper alcoholamine complexes and copper chelates; B. Preparation of an organic compound: The organic compound comprises a reducing agent, a binder, a dispersant, and a solvent. The reducing agent is selected from one or more combinations of fatty amines, ethanolamines, alkylamines, formic acid, acetic acid, oxalic acid, ethylene glycol, propylene glycol, glycerin, formaldehyde, acetone, aspartic acid, and citric acid. The binder is selected from one or more combinations of ethyl cellulose, hydroxypropyl methylcellulose, polyvinyl alcohol, acrylic thickener, polyvinylpyrrolidone, polyvinyl butyral, and polyacrylate. The dispersant is selected from one or more combinations of polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, sodium polyacrylate, sodium dodecyl sulfate, ethylenediaminetetraacetic acid, and citric acid. The solvent is selected from one or more combinations of ethanol, isopropanol, and polyols. The reducing agent, the binder, the dispersant, and the solvent are mixed to prepare the organic compound. C. Preparation of a sintering agent: The sintering aid and the organic compound are mixed to prepare a sintering agent. D. Preparation of copper powder: The copper powder contains copper particles with a micron diameter and copper particles with a nanometer diameter, with a particle size range of 50 nanometers to 1 micrometer; E. Preparation of pressureless sintering copper adhesive: The copper powder and the adhesive are mixed to prepare pressureless sintering copper adhesive. The pressureless sintering copper adhesive has the following components by weight percentage: 2-5% of the sintering aid, 13-20% of the organic matter and 75-85% of the copper powder. The components of the reducing agent, the binder, the dispersant and the solvent in the organic matter have the following weight percentages: 1-5% of the reducing agent, 1-5% of the binder, 1-5% of the dispersant and 5-10% of the solvent.

2. A pressureless sintering copper adhesive, comprising a sintering aid, an organic compound, and copper powder, wherein the sintering aid, the organic compound, and the copper powder are mixed to form the pressureless sintering copper adhesive, and the copper powder comprises copper particles with a micron-sized particle size and copper particles with a nano-sized particle size ranging from 50 nanometers to 1 micrometer; furthermore, the organic compound comprises a reducing agent, a binder, a dispersant, and a solvent, wherein the reducing agent, the binder, the dispersant, and the solvent are mixed to form the organic compound; wherein, The sintering aid is selected from one or more of the following: copper amine complex, copper carboxylic acid complex, copper oxalic acid complex, copper-amine-carboxylic acid co-complex, copper alcoholamine complex, and copper chelate; the reducing agent is selected from one or more of the following: fatty amine, ethanolamine, alkylamine, formic acid, acetic acid, oxalic acid, ethylene glycol, propylene glycol, glycerol, formaldehyde, acetone, aspartic acid, and citric acid; the binder is selected from one or more of the following: ethyl cellulose, hydroxypropyl methylcellulose, polyvinyl alcohol, acrylic thickener, polyvinylpyrrolidone, polyvinyl butyral, and polyacrylate; and the dispersant is selected from polyvinylpyrrolidone. The solvent is selected from one or more of the following: ketone, polyethylene glycol, polyvinyl alcohol, sodium polyacrylate, sodium dodecyl sulfate, ethylenediaminetetraacetic acid, and citric acid; the solvent is selected from one or more of the following: ethanol, isopropanol, and polyol; the pressureless sintering copper adhesive comprises, by weight percentage, 2-5% of the sintering aid, 13-20% of the organic matter, and 75-85% of the copper powder; and the organic matter comprises, by weight percentage, 1-5% of the reducing agent, 1-5% of the binder, 1-5% of the dispersant, and 5-10% of the solvent.

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