Ckd Praha, Oborovy Podnik

Ceskoslovenska Akademie Ved

Jiri Kovar

Pavel Reichel

Pavel Kafunek

Michal Pellant

Jaroslav Zuna

Jindrich Kratina

Oldrich Pokorny

Otomar Spalek

Josef Schmiedberger

Pavel Trenda

Jarmila Kodymova

A method of modulating an oxygen-iodine laser comprises applying an external magnetic field having an intensity of up to 800 A.cm.sup.-1 to the active zone of the laser and, at the same time, changing the magnetic field intensity to change the output power of the laser.

Modulation of oxygen-iodine laser

An improved construction for a two or three terminal power semiconductive device provides efficient thermal and electrical conduction between the heat-generating semiconductive wafer and the associated terminal electrodes with the use of a permanent, flowable thin layer of liquid metal therebetween. The liquid metal is carried in annular reservoirs within the outer surfaces of the terminal electrodes confronting the planar surfaces of the wafer, and serve to conduct the heat from the wafer to a hollow heat-dissipating well within the terminal electrodes. The wall of the well is made porous or is otherwise configured or reinforced to effectively increase the surface area thereof to aid in heat dissipation. If desired, an auxiliary seal-bearing groove is disposed concentric with and radially inwardly of the reservoir on at least one of the terminal electrodes, such groove bearing an O-ring or similar seal which bears against the confronting surface of the wafer to confine the flow of the liquid metal layer.

Heat sink cooled, semiconductor device assembly having liquid metal

A flat surface of a planar power semiconductive element, such as a thyristor or diode, is adjustably urged downwardly against a heat sink in electrical and thermal contact therewith by means of a spring-loaded eccentric element. The spring extends transversely over the opposite surface of the semiconductive element between a pair of anchor members carried by the heat sink. The eccentric is secured to an intermediate portion of the transversely extending spring, and is adapted to rotate in a vertical plane whereby successive portions of the eccentric periphery are urged with different pressures downwardly against the opposed surface of the semiconductive element, either directly or through an insulating spacer element. If desired, a pair of flattened abutment areas may be established on diametrically opposed portions of the eccentric periphery to correspondingly define a two-position stable adjustment of the bearing pressure.

Arrangement for adjustably urging a semi-conductive element against a

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Prague, Czechia

Jiri Kovar