Thomson-csf

Jean Doyen

Jean C Resneau

Jean-Claude Resneau

Robert Ribier

Philippe Morel

Pierre Roset

Marius Cirio

The substrate is formed by a plate of boron nitride having a composition of 42% B, 53.5% N.sub.2, containing between 1.5 and 2.5% O.sub.2, and 1.5% Ca. The surface is increased in hardness and made non-friable by deposition of a glass film to a depth within the range of 10 to 15 microns. This deposit permits surface metallization and ensures cohesion of the boron nitride grains.

Substrate for a microwave electronic circuit and a method for the making

A base comprising a metal mounting stud to which is fixed a locally metallized insulating plate of the beryllium oxide type. In order to very accurately position active or passive component or components on the insulating plate, at least one connecting electrode comprises at least one abutment zone against which is placed at least one component. This makes it possible to obtain a very good reproducibility of the electrical performances of the device. Such a mounting is applied to ultra-high frequency devices, particularly those incorporating a pre-matching circuit.

Base for encapsulating components with coplanar electrodes

A device for connecting in parallel high power transistors in very high frequency having a first plate serving as an electrical and thermal earth plane and a second electrically insulating plate supporting two metallized zones for connection respectively to the system of first parallel-connected electrodes of a transistor and a system of second parallel-connected electrodes of the same transistors, the third electrodes being connected to earth. The transistors, in the form of monolithic systems, are respectively placed on electrically insulating and thermally conductive plates welded to the first zone, while connecting the first electrodes to a first series of terminals and connecting the second electrodes to a second series of terminals. The metallized zones are respectively connected to the terminals of each series by conductors passing through the second electrically insulating plate, the transistors being inserted between the first and second plates.

Device for connecting in parallel power transistors in very high

A process of construction of a device for hermetic sealing in a case comprising a sealed ceramic crossover formed by a metal conductor, without having recourse to the technology of cast alumina, which is delicate and costly, and without using sealing glass which is undesirable for very high frequencies. The process comprises the manufacture of molded parts by pressing green alumina to which binders have been added, so as to obtain a case bottom and a frame, which is metalized only after previous firing at 1000.degree. C., using the molybdenum-manganese deposit by silk-screen printing, then which is sintered at the normal temperature of alumina at 1500.degree. C.

Process for sealing VHF component in case

A low thermal resistance insulating support permitting thermal stresses in the base of a high power component incorporating a beryllium oxide element without fractures or flaws occurring. The support includes a dissipating support made from copper, whose two large faces are slotted to at least partly house a beryllium oxide disk which receives a component and its connections to the outside. Such also completely houses a molybdenum disk with an expansion coefficient close to that of the beryllium oxide.

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Paris, France

Jean Doyen