Surface modification method of copper powder for conductive paste

A conductive paste and surface modification technology, applied in the direction of coating, etc., can solve the problems of difficulty in inhibiting oxidation and inapplicability, and achieve the effects of improved stability, low cost, and no special equipment requirements

Inactive Publication Date: 2008-10-01
CENT SOUTH UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that expensive chemical reagents are required; the main reason is that only the oxide film on the surface of the copper powder is removed in the pickling stage, and the active part on the surface of the copper powder is not inertized. In the later stage, due to the increase of the pH of the solution system, the surface of the copper powder is oxidized again. This oxide film is a low-temperature oxide film, which is loose and porous, and it is difficult to inhibit oxidation.
Therefore, this method is not suitable for the treatment of copper powder for conductive paste

Method used

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  • Surface modification method of copper powder for conductive paste
  • Surface modification method of copper powder for conductive paste
  • Surface modification method of copper powder for conductive paste

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Add 80g copper powder to 0.5L aqueous solution containing 0.05mol glycerol, add 0.15mol of formic acid and oleic acid mixed acid, the mixing ratio is 4:1, stir and mix for 60min, add 0.2mol of sodium hypophosphite, Under a protective atmosphere, gradually raise the temperature to 70°C, keep the reaction for 120 minutes, add 0.25 mol of diethylenediamine, keep the reaction for 90 minutes, then separate the liquid from the solid, wash and dry in vacuum.

Embodiment 2

[0036] Add 120g of copper powder to 0.5L aqueous solution containing 0.1mol glycerol, add 0.37mol of mixed acid of citric acid and oleic acid, the mixing ratio is 5:1, stir and mix for 90min, add 0.3mol of hydrazine hydrate, in Under a protective atmosphere, after gradually raising the temperature to 50°C, heat-retain for 90 minutes, add 0.45 mol of tetramethylethylenediamine, heat-retain for 90 minutes, then separate liquid from solid, wash and dry in vacuum.

Embodiment 3

[0038] Add 65g copper powder to 0.5L aqueous solution containing 0.05mol triethylene glycol, add 0.2mol tartaric acid and oleic acid mixed acid, the mixing ratio is 6:1, stir and mix for 60min, add 0.4mol glucose, in a protective atmosphere , and gradually raise the temperature to 90°C, keep the reaction for 150 minutes, add 0.12mol of diethylenediamine, keep the reaction for 90 minutes, then separate the liquid from the solid, wash and dry in vacuum.

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Abstract

The invention provides a method for decorating the surface of copper powder used in conductive paste, which relates to the processing of metal powder, in particular to the characteristic improvement and the coating of the metal powder. The method is characterized in that: the copper powder is dispersed into a water solution that contains a dispersing agent, an organic mixed acid is added, and the mixture is stirred and mixed for 30 to 90 min; a reductant is added, temperature is increased to 50 to 90 DEG C and heat preservation reaction occurs for 60 to 120 min; a coating agent is added for carrying out the heat preservation reaction for 60 to 150 min; then liquid-solid separation, washing and vacuum drying are carried out to finish the method. The adding amount of additional substances is as follows: the copper powder : the dispersing agent : the organic mixed acid : the reductant : the coating agent is equal to 1 : 0.05 to 0.25 : 0.05 to 0.5 : 0.1 to 1 : 0.05 to 0.5, and the ratio of liquid to solid is 4 to 8 : 1. The antioxidant capability of the copper powder is improved by the two processes of recrystallization and organic coating, thereby solving the problem of the serious oxidation of copper during the sintering process of the paste and greatly improving the stability of the conductive paste due to the existence of an organic-inorganic interface.

Description

technical field [0001] The present invention relates to the processing of metal powder, in particular to the improvement of its properties and the coating of the powder, and more specifically to the surface modification method and modification technology of the copper powder. Background technique [0002] With the development of miniaturization and functionalization of electronic components, the development of electronic paste is greatly promoted, especially the wide application of silver-based electronic paste. However, due to the migration of silver in a humid environment, which reduces the reliability of electronic components, and the high price of silver powder, it is extremely urgent to develop a new generation of base metal paste with high performance and low cost. Copper-based conductive paste is considered to be an ideal replacement product. However, the conductivity of the slurry is greatly reduced because the copper powder is easily oxidized. Therefore, how to im...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F1/02
Inventor 李启厚李玉虎刘志宏张多默
Owner CENT SOUTH UNIV
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