Abstract: So as to avoid untimely triggering of a sensitive thyristor, it is given the structure shown in the accompanying figure, with a passivated furrow SP3 which divides the gate layer P1 into two completely separate zones (zone B and zone C). Zone B comprises on the one hand the whole of the cathode region N1 and on the other a first surface portion P'1 of the P layer adjacent the furrow SP3. Zone C comprises on the one hand an auxiliary N type surface region N3 and on the other a second surface portion P"1 of the layer P1. The cathode metallization CME1 covers the cathode region N1 without covering the region P'1. The gate metallization MG covers at least partially the region P'1. An auxiliary metallization MA separate from the others covers the region P'1 and the region N3.

Abstract: The invention provides a triac whose resistance to untimely striking in the presence of steep voltage fronts is increased. For this, a part of the gate electrode is provided above a five layer structure, a part above a four layer structure and finally a small part above a three layer structure.

Abstract: In the pressure association of a main component such as a Darlington transistor or an amplifying gate thyristor and a storage diode, a specific destorage diode comprising an annular junction. Thus, transversally to the center of the diode a N.sup.+ NN.sup.+ structure appears while, transversally to the periphery an N.sup.+ NP structure exists.

Abstract: An over-voltage clipping diode comprising a plurality of serial elementary diode chips. Each diode chip is sandwiched between two distributor blocks made of a material which has a high thermal conductivity and a high thermal capacity with respect to the semi-conductive material of the diode chips.