Ishihara Chemical Co., Ltd.

Applied Nanotech Holdings, Inc.

Tomio Kudo

Yusuke Maeda

Yuichi Kawato

Kazushige Miyamoto

In a conductive film forming method using photo sintering, a conductive film having low electric resistance is easily formed. Disclosed is a conductive film forming method in which a conductive film is formed using a photo sintering, which includes the steps of: forming a liquid film made of a copper particulate dispersion on a substrate, drying the liquid film to form a copper particulate layer, subjecting the copper particulate layer to photo sintering to form a conductive film, attaching a sintering promoter to the conductive film, and further subjecting the conductive film having the sintering promoter attached to photo sintering. The sintering promoter is a compound which removes copper oxide from metallic copper. Thereby, the sintering promoter removes a surface oxide film of copper particulates in the conductive film.

Conductive film forming method and sintering promoter

The copper particulate dispersion includes copper particulates, at least one kind of a dispersion vehicle containing the copper particulates, and at least one kind of dispersant which allows the copper particulates to disperse in the dispersion vehicle. The copper particulates have a center particle diameter of 1 nm or more and less than 100 nm. The dispersion vehicle is a polar dispersion vehicle. The dispersant is a compound having at least one acidic functional group, which has a molecular weight of 200 or more and 100,000 or less, or a salt thereof. Whereby, the dispersant has compatibility with dispersion vehicle and a surface of copper particulates is coated with dispersant molecules, and thus the copper particulates are dispersed in the dispersion vehicle.

Copper particulate dispersion, conductive film forming method and circuit board

An object is to provide a copper particulate dispersion which is suited to discharge in the form of droplets. The copper particulate dispersion includes copper particulates, at least one kind of a dispersion vehicle containing the copper particulates, and at least one kind of dispersant which allows the copper particulates to disperse in the dispersion vehicle. The copper particulates have a center particle diameter of 1 nm or more and less than 100 nm. The dispersion vehicle is a polar dispersion vehicle having a boiling point within a range from 150&#xb0; C. to 250&#xb0; C. Whereby, when the copper particulate dispersion is discharged in the form of droplets, clogging at the discharge portion caused by drying of the dispersion vehicle is prevented and the viscosity is low for its high boiling point, and thus the copper particulate dispersion is suited to discharge in the form of droplets.

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Hyogo, Japan

Tomio Kudo