Silver-dispersed copper powder, process for producing the powder and conductive paste utilizing the powder
AssigneeDowa Mining Co., Ltd.
InventorsKazushi Sano, Yoshihiro Okada, Hiromasa Miyoshi, Yoshiomi Takada
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Abstract
Silver-dispersed copper powder whose particles have substantially no discrete metallic silver on their surfaces is produced by subjecting a silver-adhered copper powder composed of copper particles having silver adhered to the surfaces thereof to heat treatment in a non-oxidizing atmosphere at a temperature of 150-600° C. A conductive paste using the powder as filler resists migration.
Claims9
A process for producing silver-dispersed copper powder comprising a step of subjecting a silver-adhered copper powder composed of copper particles having silver adhered to the surfaces thereof to heat treatment in a non-oxidizing atmosphere at a temperature of 150-600° C.
A process for producing silver-dispersed copper powder comprising;
- a step of precipitating copper hydroxide by reacting an aqueous solution of a copper salt and an alkali to obtain a suspension containing copper hydroxide,
- an intermediate reduction step effected by adding a reducing agent to the suspension to reduce the copper hydroxide to cuprous oxide,
- a final reduction step, conducted after blowing an oxygen-containing gas into the suspension containing cuprous oxide to effect oxidizing treatment, of reducing the cuprous oxide to metallic copper by addition of hydrazine hydrate or an organic reducing agent to the suspension,
- a step of adding silver nitrate to the obtained suspension containing the reducing agent and metallic copper powder to obtain silver-adhered copper powder, and
- a step of subjecting the silver-adhered copper powder to heat treatment in a non-oxidizing atmosphere at a temperature of 150-600° C.
Silver-dispersed copper powder comprising 0.5-10 wt % of Ag and the balance of Cu and unavoidable impurities whose particles have substantially no discrete metallic silver on their surfaces and are of an average diameter of not greater than 10 μm.
Conductive paste using as conductive filler silver-dispersed copper powder comprising 0.5-10 wt % of Ag and the balance of Cu and unavoidable impurities whose particles have substantially no discrete metallic silver on their surfaces and are of an average diameter of not greater than 10 μm.
A conductor for a printed electronic circuit using conductive paste containing silver-dispersed copper powder comprising 0.5-10 wt % of Ag and the balance of Cu and unavoidable impurities whose particles have substantially no discrete metallic silver on their surfaces and are of an average diameter of not greater than 10 μm.
Dependencies are inferred from the claim text.