Dowa Electronics Materials Co., Ltd.

Aiko Hirata

Toshihiko Ueyama

Keiichi Endoh

Yutaka Hisaeda

Noriaki Nogami

Akihiro Miyazawa

Hiroshi Kamiga

There is provided an electrically conductive paste which can prevent the increase of the volume resistivity of an electrically conductive film formed from the electrically conductive paste even if the electrically conductive film is heated to a soldering temperature of about 380&#xb0; C. when the electrically conductive paste is a resin type electrically conductive paste using a silver powder and a silver-coated copper powder. In an electrically conductive paste containing a resin, a silver powder and a silver-coated copper powder having a copper powder, the surface of which is coated with a silver layer, the resin is an epoxy resin having a naphthalene skeleton, and there is added a dicarboxylic acid, preferably a dicarboxylic acid having a rational formula of HOOC&#x2014;(CH)&#x2014;COOH (n=1-8), and more preferably a dicarboxylic acid having a rational formula of HOOC&#x2014;(CH)&#x2014;COOH (n=4-7).

Electrically conductive paste

There is provided a silver-coated copper powder which can improve the conversion efficiency of a solar cell in comparison with conventional silver-coated copper powders when it is used in an electrically conductive paste used for forming the busbar electrodes of the solar cell, the silver-coated copper powder being capable of producing a solar cell having a high conversion efficiency which is the same degree as that of a solar cell using silver powder, and a method for producing the same. A silver-coated copper powder obtained by coating the surface of a copper powder, which is obtained by the atomizing method or the like, with 5 wt % or more (with respect to the silver-coated copper powder) of a silver containing layer of silver or a silver compound, is added to a cyanide solution, such as a potassium silver cyanide solution, a potassium gold cyanide solution, a potassium cyanide solution or a sodium cyanide solution, to cause the copper powder coated with the silver containing layer to contain 3 to 3000 ppm of cyanogen.

Silver-coated copper powder and method for producing same

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.

Growing community of inventors

Tokyo, Japan

Aiko Hirata