Fujitsu Corporation

Tadaaki Shono

Masayuki Kitajima

Masakazu Takesue

Yutaka Noda

Yasuo Yamagishi

Hiroki Uchida

Masayuki Ochiai

Ryoji Matsuyama

Motoko Fujioka

Hitoshi Homma

A high melting point solder alloy superior in oxidation resistance, in particular a solder alloy provided with both a high oxidation resistance and high melting point suitable for filling fine through holes of tens of microns in diameter and high aspect ratios and forming through hole filling materials, comprising a zinc-aluminum solder alloy containing 0.001 wt % to 1 wt % of aluminum and the balance of zinc and unavoidable impurities.

Zinc-aluminum solder alloy

A solder alloy having a solderability comparable to that of a conventional Pb&#x2014;Sn solder alloy without having a detrimental effect on the environment and a soldered bond using the same. A solder alloy consisting of Zn: 4.0-10.0 wt %, In: 1.0 to 15.0 wt %, Al: 0.0020 to 0.0100 wt %, and the balance of Sn and unavoidable impurities. A soldered bond of an electric or electronic device composed of the above solder alloy.

Solder alloy and soldered bond

A solder paste, includes a flux, a solder alloy particle scattered or mixed in the flux and including Sn and Zn as composition elements, and a metal particle scattered or mixed in the flux and including an element in the IB group in the periodic table as a composition element.

Solder paste and electronic device

The present invention provides a soldering method and a soldered joint securing a strength of joint equivalent to soldering using a conventional Pb&mdash;Sn solder alloy without having a detrimental effect on the environment and without causing a rise in cost. A soldering method comprising a step of covering Cu electrodes of electronic equipment by a rust-proofing coating consisting of an organic compound including N and a step of forming soldered joints on the covered Cu electrodes, by using a solder material consisting of at least 2.0 wt % and less than 3 wt % of Ag, 0.5 to 0.8 wt % of Cu, and a balance of Sn and unavoidable impurities. The solder material used in the present invention further contains not more than 3 wt % in total of at least one element selected from the group consisting of Sb, In, Au, Zn, Bi, and Al.

Soldering method and soldered joint

A Pb-free solder alloy and a soldered bond using the same, in which the solder alloy has no harmful environmental effect but has a solderability comparable to that of the conventional Pb&mdash;Sn solder alloy. The solder alloy of the present invention either consists of Zn: 3.0-14.0 wt %, Al: 0.0020-0.0080 wt %, and the balance of Sn and unavoidable impurities or consists of Zn: 3.0-14.0 wt %, Bi: 3.0-6.0 wt %, Al: 0.0020-0.0100 wt %, and the balance of Sn and unavoidable impurities. The soldered bond of the present invention consists of either of the present inventive solder alloys.

Growing community of inventors

Kawasaki, Japan

Tadaaki Shono