Dowa Electronics Materials Co., Ltd.

Yutaka Hisaeda

Toshihiko Ueyama

Keiichi Endoh

Akihiro Miyazawa

Aiko Nagahara

Shuji Kaneda

Aiko Hirata

Kimikazu Motomura

Tatsuya Kariyasu

Kosuke Iha

Kimitaka Sato

Satoru Kurita

Yu Saito

Kozo Ogi

Taku Okano

A method of bonding two different substances includes the steps of: applying a bonding material containing a flux component that includes an organic material having at least two carboxyl groups to a bonding surface of a bonding object, disposing an object to be bonded on the bonding material, performing preliminary firing at a preset temperature in a state in which the object to be bonded is disposed, and performing a main firing by heating at a temperature higher than the temperature of the preliminary firing.

Bonding method using bonding material

A bonded product is obtained by applying a silver paste containing silver nanoparticles having an average primary particle diameter of 1 to 200 nm, and performing firing. A diameter of a crystallite of the bonded product on a (111) plane of Ag when heated at 250&#xb0; C. for 10 minutes in an inert atmosphere is 65 nm or larger.

Bonding material and bonding method using the same

A method suitable for mass production of nanoparticles with a uniform particle diameter is provided. It is an object to provide a powder of the nanoparticle obtained by this method, a dispersion containing the nanoparticles, and a paste containing the nanoparticles. There is provided a method for manufacturing silver particles including the step of reducing silver in a silver solution containing a protective agent composed of an organic material and a copper component in an amount of 1 to 1,000 ppm relative to the amount of silver to obtain particles having an average particle diameter (D) of 5 to 100 nm as measured using a transmission electron microscope.

Fine silver particle powder, method for manufacturing the same, silver paste using the powder and method of use of the paste

There is provided a bonding material capable of forming a bonding body under an inert gas atmosphere such as a nitrogen atmosphere, and capable of exhibiting a bonding strength that endures a practical use even if not a heat treatment is applied thereto at a high temperature, which is the bonding material containing silver nanoparticles coated with a fatty acid having a carbon number of 8 or less and having an average primary particle size of 1 nm or more and 200 nm or less, and silver particles having an average particle size of 0.5 &#x3bc;m or more and 10 &#x3bc;m or less, and an organic material having two or more carboxyl groups.

Bonding material and bonding body, and bonding method

A method of forming a bonded product using metal nanoparticles is provided. More specifically, provided is a paste containing a flux component that can form a metal phase even in an inert atmosphere. The use of this paste allows a bonding material that can give a practically acceptable bonding strength to be provided in an inert atmosphere such as a nitrogen atmosphere at low temperatures without performing conventionally used pressurization. The paste is a bonding material configured to include: silver nanoparticles having an average primary particle diameter of 1 to 200 nm and coated with an organic material having 8 or less carbon atoms; a flux component having at least two carboxyl groups; and a dispersion medium. The use of this bonding material allows materials to be bonded even at a temperature of 300&#xb0; C. or lower.

Fine silver particle powder, method for manufacturing the same, silver paste using the powder, and method of use of the paste

In a bonding material using nanoparticles and a bonding method, use in combination with microparticles is proposed. However, there is the problem in which it is not easy to uniformly mix the nanoparticles and the microparticles. The present invention uses a bonding material including metal nanoparticles having an average particle diameter of 100 nm or less and a surface coated with an organic substance having 6 to 8 carbon atoms, and a polar solvent in an amount of 5 to 20% by mass with respect to a powder of the metal nanoparticles, and objects to be bonded with the bonding material interposed therebetween are fired at 200 to 350&#xb0; C. under pressure. Thus, the metal nanoparticles are melted and returned to a bulk material, and therefore a bonding layer of the bulk material can be formed at a low temperature equal to or lower than a melting point.

Bonding material using metal nanoparticles coated with C6-C8 fatty acids, and bonding method

Provided is a bonding material which enables formation of a bonded article in nitrogen, and can exhibit bonding strength to withstand practical use while having reduced bonding fluctuations between samples without a heat treatment procedure under pressurized or high temperature conditions. The bonding material comprises: silver nanoparticles having an average primary particle diameter of 1 to 200 nm and coated with an organic substance having 8 carbon atoms or less; a dispersion medium having a boiling point of 230&#xb0; C. or higher; and a flux component including an organic matter having at least two carboxyl groups. Particularly, it is preferable to use the silver nanoparticles and submicron silver particles in combination.

Low-temperature-sinterable bonding material, and bonding method using the bonding material

A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 800 &#xb0; C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.

Composition containing fine silver particles, production method thereof, method for producing fine silver particles, and paste having fine silver particles

A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 80&#xb0; C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.

A composition containing fine silver particles which have a uniform particle size, can form a fine drawing pattern, and have a small environmental impact, a method for producing that composition, a method for producing fine silver particles, and a paste having fine silver particles are provided. The fine silver particles are produced by carrying out a fluid preparation step of preparing a reduction fluid, a silver reaction step, and a filtration/washing step. The reaction step is carried out by adding an aqueous silver nitrate fluid to a reduction fluid whose temperature has been increased to a range between 40 and 800&#xb0; C. The aqueous silver nitrate fluid is added at a stretch. The composition containing fine silver particles is produced by dispersing the composition containing the fine silver particles in a polar fluid.

Provided is a method for producing a silver particle powder excellent in the dispersibility in a liquid organic medium having a low polarity, which comprises reducing a silver compound in an alcohol having a boiling point of from 80&#xb0; C. to 200&#xb0; C. or in a polyol having a boiling point of from 150 to 300&#xb0; C., at a temperature of from 80&#xb0; C. to 200&#xb0; C. under reflux while maintaining the stream having a Reynolds number of not more than 3.70&#xd7;10. The stream having a Reynolds number of not more than 3.70&#xd7;10can be maintained by stirring with a stirring power of not more than 5.68&#xd7;10W. According to the method, a silver particle powder having good low-temperature sinterability and good dispersibility and suitable for use for microwiring formation can be obtained at a high yield.

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Okayama, Japan

Yutaka Hisaeda