Hitachi, Ltd.

Renesas Electronics Corporation

Renesas Technology Corp.

Tasao Soga

Tetsuya Nakatsuka

Hanae Shimokawa

Toshiharu Ishida

Kazuma Miura

Asao Nishimura

Hiroaki Okudaira

Koji Serizawa

Yoshiharu Inaba

Fumiyuki Kobayashi

Masahide Okamoto

Hirokazu Nakajima

Tsuneo Endoh

Tadao Kushima

Mikio Negishi

Kazuji Yamada

Hiroaki Hachino

Mamoru Sawahata

Hanae Hata

Masahide Harada

Katsumi Ishikawa

Kazuhiro Suzuki

Satoru Ogihara

Nobuyuki Ushifusa

Fumio Nakano

Masahiro Okamura

Takaya Suzuki

Yuji Fujita

Tsuneaki Kamei

Sunao Funakoshi

Katsuaki Saito

Masato Nakamura

Hiroichi Shinohara

Daisuke Kawase

Hideki Mukuno

Masahiro Gooda

Toshihiro Hachiya

Eiichi Morisaki

Hiroshi Yamaguchi

Takashi Yokoyama

Tatsuya Suzuki

Takahiro Daikoku

Kenji Miyata

Ken Takahashi

Hideo Suzuki

Kenichi Yamamoto

Hiroyoshi Matsumura

Seigou Yukutake

Yukio Hishinuma

Kunio Miyazaki

Shunichi Numata

Mitugu Shirai

Shunsuke Nogita

Hideo Arakawa

Atsushi Morihara

Yasutoshi Kurihara

Yasuo Amano

Suguru Sakaguchi

Asao Nakano

Yoko Wakui

Shuntaro Koyama

Kousei Nagayama

Michio Ooue

Yuji Ochiai

Yoshio Naganuma

Tomio Yasuda

Toshitaka Yamamoto

Yuuji Ochiai

Marahiro Goda

Kanko Ishida, Legal Representative

Provided are a bonded structure by a lead-free solder and an electronic article comprising the bonded structure. The bonded structure has a stable bonding interface with respect to a change in process of time, an enough strength and resistance to occurrence of whiskers while keeping good wettability of the solder. In the bonded structure, a lead-free Sn&#x2014;Ag&#x2014;Bi alloy solder is applied to an electrode through an Sn&#x2014;Bi alloy layer. The Sn&#x2014;Bi alloy, preferably, comprises 1 to 20 wt % Bi in order to obtain good wettability of the solder. In order to obtain desirable bonding characteristics having higher reliability in the invention, a copper layer is provided under the Sn&#x2014;Bi alloy layer thereby obtaining an enough bonding strength.

Pb-free solder-connected structure

Pb-free solder-connected structure and electronic device

Use of Pb-free solder has become essential due to the environmental problem. A power module is formed by soldering substrates with large areas. It is known that in Sn-3Ag-0.5Cu which hardly creeps and deforms with respect to large deformation followed by warpage of the substrate, life is significantly shortened with respect to the temperature cycle test, and the conventional module structure is in the situation having difficulty in securing high reliability. Thus, the present invention has an object to select compositions from which increase in life can be expected at a low strain rate. In Sn solder, by doping In by 3 to 7% and Ag by 2 to 4.5%, the effect of delaying crack development at a low strain rate is found out, and as a representative composition stable at a high temperature, Sn-3Ag-0.5Cu-5In is selected. Further, for enhancement of reliability, a method for partially coating a solder end portion with a resin is shown.

Semiconductor power module

Each of junctions formed between a semiconductor device and a substrate comprises metal balls of Cu, or other materials and compounds of Sn and the metal balls, and the metal balls are bonded together by the compounds.

Solder composition for electronic devices

Semiconductor power module including epoxy resin coating

A solder foil formed from a material comprising particles of Cu, etc. as metal particles and Sn particles as solder particles by rolling is suitable for solder bonding at a high temperature side in temperature-hierarchical bonding, and semiconductor devices and electronic devices produced by use of such solder bonding have distinguished reliability of mechanical characteristics, etc.

Solder foil, semiconductor device and electronic device

A power semiconductor module having an increased reliability against thermal fatigue includes a power semiconductor element, a lower-side electrode connected to the lower side of the element, a first insulating substrate connected to the upper side of the lower-side electrode and having metallic foils bonded on both surfaces thereof, an upper-side electrode connected to the upper side of the power semiconductor element, a second insulating substrate connected to the upper side of the upper-side electrode and having metallic foils bonded on both surfaces thereof, a first heat spreader connected to the lower side of the first insulating substrate, and a second heat spreader connected to the upper side of the second insulating substrate. The power semiconductor element and the first and second insulating substrates are sealed with a resin.

Power semiconductor module

A power semiconductor module with its thermal resistance and overall size reduced. Insulating substrates with electrode metal layers disposed thereon are joined to both the surfaces of a power semiconductor chip by using, for example, soldering. Metal layers are disposed also on the reverse surfaces of the insulating substrates and the metal layers are joined to the heat spreaders by using brazing. Heat radiating fins are provided on the heat radiating surface of at least one of the heat spreaders. The heat radiating side of each of the heat spreaders is covered by a casing to form a refrigerant chamber through which refrigerant flows to remove heat transmitted from the semiconductor chip to the heat spreader.

Each of junctions formed between a semiconductor device and a substrate comprises metal balls of Cu, etc., and compounds of Sn and the metal balls, and the metal balls are bonded together by the compounds.

Semiconductor device with lead-free solder

A semiconductor module solder bonding of high reliability in which the heat resisting properties of the circuit substrate and electronic parts are taken into consideration. In order to achieve this, there are provided semiconductor devices each having solder bumps as external pads, and a circuit substrate bonded to the external pads of each of the semiconductor devices through a solder paste, each of the solder bumps being made of a first lead-free solder, the solder paste being made of a second lead-free solder having a melting point lower than that of the first lead-free solder.

Semiconductor device having solder bumps reliably reflow solderable

Each of junctions formed between a semiconductor device and a substrate comprises metal balls of Cu etc. and compounds of Sn and the metal balls, and the metal balls are bonded together by the compounds.

Electronic device

A method of producing an electronic device by connecting a lead of a semiconductor device with an electrode of a circuit board to form a bonded structure. In the bonded structure, a lead-free Sn&#x2014;Ag&#x2014;Bi alloy solder is applied to an electrode through an Sn&#x2014;Bi alloy layer. The Sn&#x2014;Bi alloy, preferably, comprises 1 to 20 wt % Bi in order to obtain good wettability of the solder. In order to obtain desirable bonding characteristics having higher reliability in the invention, a copper layer is provided under the Sn&#x2014;Bi alloy layer thereby obtaining an enough bonding strength.

Method of producing an electronic device having a PB free solder connection

In a solder that realizes high-temperature-side solder bonding in temperature-hierarchical bonding, a connection portion between a semiconductor device and a substrate is formed of metal balls made of Cu or the like and compounds formed of metal balls and Sn, and the metal balls are bonded together by the compounds.

Solder

Growing community of inventors

Fujisawa, Japan

Tasao Soga