Denso Corporation

Senju Metal Industry Co., Ltd.

Hiroyuki Yamada

Shunsaku Yoshikawa

Takashi Hagiwara

Yuji Kawamata

Tsukasa Ohnishi

Yoshitsugu Sakamoto

Noriyasu Inomata

Yoshie Yamanaka

Kenzo Tadokoro

Kazuyuki Hamamoto

Takuji Sukekawa

A soldering flux which is suitable as a no-clean post flux in flow soldering and which can prevent the formation of whiskers which tends to occur when soldering electronic parts to a printed circuit board using a lead-free solder (such as Sn-3.0Ag-0.5Cu) having a higher Sn content and a higher melting point than the eutectic solder contains, in addition to a rosin as a base resin and an activator, 0.2-4 mass % of at least one compound selected from acid phosphate esters and derivatives thereof. The formation of whiskers can be more effectively prevented by carrying out soldering in a nitrogen atmosphere.

Flux for lead-free solder and soldering method

A semiconductor device is provided which has internal bonds which do not melt at the time of mounting on a substrate. A bonding material is used for internal bonding of the semiconductor device. The bonding material is obtained by filling the pores of a porous metal body having a mesh-like structure and covering the surface thereof with Sn or an Sn-based solder alloy.

Bonding material for semiconductor devices

A reflow soldering system wherein a heating oven is provided with a contact heating unit which has a transport rail and a top heat transfer heater, and with a hot gas blowing heating unit, the transport rail and top heat transfer heater are respectively provided with heaters which heat the outer edge part of the printed circuit board, and the transport rail or top heat transfer heater moves in an up-down direction so that the transport rail and top heat transfer heater clamp and heat the outer edge part of the printed circuit board.

Reflow soldering system

Growing community of inventors

Obu, Japan

Hiroyuki Yamada