Dowa Electronics Materials Co., Ltd.

Taro Nakanoya

Hiroshi Kamiga

Kimitaka Sato

Shinya Sasaki

Noriaki Nogami

Taku Okano

Kenichi Harigae

Masaya Osako

There is provided a spherical silver powder which is capable of being sintered at a lower temperature. The spherical silver powder of spherical silver particles has cavities, each of which is formed in a corresponding one of the spherical silver particles and each of which has a major axis of 100 to 1000 nm and a minor axis of 10 nm or more, the ratio of the major axis to the minor axis (major axis/minor axis) being 5 or more, the major axis being the length of the long side of a rectangle which has a minimum area and which circumscribes the outline of a cross-section of a corresponding one of the cavities on an image of the cross-section of the corresponding one of the silver particles exposed by polishing the surface of a resin after the silver powder is embedded in the resin, and the minor axis being the length of the narrow side of the rectangle.

Spherical silver powder

Provided is a silver-tellurium-coated glass powder including: a tellurium-based glass powder containing tellurium in an amount of 20% by mass or more; and a coating layer on a surface of the tellurium-based glass powder, the coating layer containing silver and tellurium as a main component. Preferable aspects include an aspect where the coating layer containing silver and tellurium as a main component further contains a component that is other than silver and tellurium and contained in the tellurium-based glass powder, and an aspect where the component that is lo other than silver and tellurium and contained in the tellurium-based glass powder contains one or more kinds selected from zinc, lead, bismuth, silicon, lithium, and aluminum.

Silver-tellurium-coated glass powder, production method for silver-tellurium-coated glass powder, conductive paste, and production method for conductive paste

A silver powder, including: an organic substance on a surface of the silver powder, the organic substance containing at least one carboxyl group and at least one hydroxyl group in one molecule of the organic substance, wherein a ratio of (Casson yield value/BET specific surface area) is 500 or less, where the Casson yield value is a Casson yield value of a conductive paste and the BET specific surface area is a BET specific surface area of the silver powder, where the conductive paste has a composition in which the silver powder is 86% by mass, a glass fit is 1% by mass, ethyl cellulose is 0.6% by mass, texanol is 10.5% by mass, and zinc oxide is 1.9% by mass, and the conductive paste is prepared by kneading the composition with a planetary centrifugal stirrer and bubble remover and dispersing with a triple roll mill.

Silver powder, method for producing same, and conductive paste

A silver powder, including: an organic substance on a surface of the silver powder, the organic substance containing at least one carboxyl group and at least one hydroxyl group in one molecule of the organic substance, wherein a BET specific surface area of the silver powder is 0.1 m/g or more but 2.0 m/g or less, and wherein a cumulative 50% point of particle diameter (D) of the silver powder in a volume-based particle size distribution of the silver powder as measured by a laser diffraction particle size distribution analysis is 0.1 &#x3bc;m or more but 6.0 &#x3bc;m or less, and a ratio of [(D&#x2212;D)/D] is 3.0 or less, where Dis the cumulative 50% point of particle diameter, Dis a cumulative 90% point of particle diameter of the silver powder, and Dis a cumulative 10% point of particle diameter of the silver powder.

Provided is a silver micropowder coated with a protective material and capable of more drastically reducing the sintering temperature than before. The silver micropowder comprises silver particles processed to adsorb hexylamine (CH&#x2014;NH) on the surfaces thereof and having a mean particle diameter Dof from 3 to 20 nm or an X-ray crystal particle diameter Dof from 1 to 20 nm. The silver micropowder has the property of forming a conductive film having a specific resistivity of not more than 25 &#x3bc;&#x3a9;&#xb7;cm when it is mixed with an organic medium to prepare a silver coating material and when a coating film formed of it is fired in air at 120&#xb0; C. Even when fired at 100&#xb0; C., it may form a conductive film having a specific resistivity of not more than 25 &#x3bc;&#x3a9;&#xb7;cm. The silver micropowder can be produced by mixing a silver particle dispersion, as monodispersed in an organic medium, of silver particles coated with a primary amine A having an unsaturated bond and having a molecular weight of from 200 to 400, and hexylamine, and then keeping the mixture at 5 to 80&#xb0; C. with stirring to thereby form precipitated particles.

Silver micropowder, silver ink, silver coating, and methods for production of these materials

Provided are silver nanoparticles having a good affinity (that is, dispersibility) for y-butyrolactone (CHO), an organic solvent which has a relatively high boiling point though having a relatively small molecular weight, and has a low viscosity and a low surface tension and which has little irritating odor. The above problems are solved by providing a silver micropowder excellent in affinity for at least y-butyrolactone, which comprises silver particles processed to adsorb at least one of 1,4-dihydroxy-2-naphthoic acid (CHO) and gallic acid (CHO) on the surfaces thereof and having an X-ray crystal particle diameter Dof from 1 to 40 nm, preferably from 1 to 15 nm. The invention also provides a silver ink obtained by dispersing silver particles processed to adsorb an organic compound having a carboxyl group on the surfaces thereof and having an X-ray crystal particle diameter Dof from 1 to 40 nm, preferably from 1 to 15 nm (or having a mean particle diameter D, as measured through TEM microscopy, of from 3 to 40 nm, preferably from 4 to 15 nm), in y-butyrolactone.

Growing community of inventors

Tokyo, Japan

Taro Nakanoya