Hitachi, Ltd.

Misuk Yamazaki

Masato Kobayashi

Shigeru Kikuchi

Satoru Kajiwara

Satoshi Matsuyoshi

Tatsuo Yamazaki

Chikara Makajima

An electrical contact comprising a contact layer for making a contact with an opposite electrical contact and a high conductive layer in an opposite side of the contact layer, the layers being integrally connected to each other, wherein the contact layer contains Cr, Cu and Te, and the high conductive layer contains copper as a main component, and wherein the high conductive layer is provided with a means for suppressing warp of the contact layer at the time of turning on of the contacts.

Electrical contact for vacuum valve

A semiconductor device comprises a semi-conductor chip bonded on a top surface inside a case electrode by a bonding material and a lead electrode bonded on a top surface of the semiconductor chip by a bonding material with a space of the case electrode filled with an insulating material for sealing the bonded sections, wherein a groove is provided on a top surface of the case electrode from an edge of the semiconductor chip, to thereby reduce heat distortion which is generated on a large scale at an end of the bonding material on account of a difference in coefficients of linear thermal expansion between the semiconductor chip and the case electrode and improve the thermal fatigue life.

Semiconductor device

There is a need to provide a semiconductor device in which strain in a bonding member resulting from the difference in thermal deformation between a lead electrode and a semiconductor chip, which are electrically bonded to each other by the bonding member, is reduced for an improved thermal fatigue lifetime and the semiconductor chip has an improved current carrying capacity and enhanced heat dissipation. In the semiconductor device having the semiconductor chip mounted on the upper surface of the case electrode by using the bonding member and a lead electrode mounted on the upper surface of the semiconductor chip by using a bonding member, while an insulating member is filled in the space of the case electrode to seal a bonded portion, a trench is provided in the upper surface of the lead electrode to reduce large thermal strain occurring at the end portion of the bonding member due to the difference in linear expansion coefficients between the lead electrode and the semiconductor chip and improve the thermal fatigue lifetime. Consideration is also given to a reduction in variations in the thickness of a connecting member.

Growing community of inventors

Kashiwa, Japan

Misuk Yamazaki