Patents Examined by F. Abraham
  • Patent number: 5001535
    Abstract: In a static induction type thyristor comprising a low impurity concentration channel region having opposed first and second major surfaces, a first main electrode region having one conductivity type and a second main electrode region having another conductivity type opposite to the one conductivity type and provided on the first and second major surfaces, respectively, and a gate region provided in the vicinity of the first main electrode region, there intervenes, between the channel region and the second main electrode region, a thin layer region having the same conductivity type as that of first main electrode region. The provision of this thin layer region contributes to allowing a markedly low impurity concentration as well as a decreased thickness of the channel region for a given maximum forward blocking voltage, making it feasible to obtain a high maximum forward blocking voltage and a high switching speed.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: March 19, 1991
    Inventors: Jun-ichi Nishizawa, Tadahiro Ohmi
  • Patent number: 4967255
    Abstract: In a controllable power semiconductor component having a pnpn layer sequence of p-type emitter layer (9), n-type base layer (8), p-type base layer (7) and n-type emitter layer (5) the critical increased field rise during turn-off is reduced as a result of an intermediate layer (11), which has a higher n-doping than the n-type base layer (8) and which is inserted between the n-type base layer (8) and the p-type base layer (7).
    Type: Grant
    Filed: August 21, 1989
    Date of Patent: October 30, 1990
    Assignee: Asea Brown Boveri Ltd.
    Inventors: Friedhelm Bauer, Horst Gruning