Copper paste for bonding

Abstract

This invention provides a copper paste for bonding, which exhibits excellent low-temperature sintering properties and bonding strength with the bonded object. The copper paste for bonding comprises a solvent, an additive, and copper powder. The solvent has a boiling point of 100°C or higher and 300°C or lower. The additive comprises an amine-based organic compound with a mass-average molecular weight of 1000 or lower. The copper powder is copper powder with a number-average particle size of 30 nm or higher and 180 nm or lower calculated from the equivalent circle diameter, and its surface is coated with a surface coating containing an organic substance satisfying conditions (1) and (2) described in the specification. The Hansen solubility parameter of the copper powder coated with the aforementioned surface coating is within 7 units of the Hansen solubility parameter of the amine-based organic compound, and the Hansen solubility parameter of the copper powder coated with the aforementioned surface coating is within 7.1 units of the Hansen solubility parameter of the solvent.

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