PROCEDE DE BRASAGE POUR LA FABRICATION DE BOITIERS PLATS, ET BOITIERS PLATS POUR COMPOSANTS ELECTRONIQUES

L'INVENTION CONCERNE UN PROCEDE DE BRASAGE.ELLE SE RAPPORTE A UN PROCEDE DE REALISATION D'UN BOITIER PLAT DANS LEQUEL UN CADRE 12 DE CONDUCTIBILITE THERMIQUE RELATIVEMENT FAIBLE EST SOUDE A UNE BASE 14 DE CONDUCTIBILITE THERMIQUE RELATIVEMENT GRANDE PAR DEUX COUCHES 28, 30 DE BRASURE PLACEES DE PART ET D'AUTRE D'UNE BAGUE INTERMEDIAIRE 26. LA BAGUE A UNE CONDUCTIBILITE THERMIQUE SUPERIEURE A CELLE DU CADRE. DE CETTE MANIERE LA COULURE DE LA BRASURE EST REDUITE AU MINIMUM.APPLICATION AUX BOITIERS DES CIRCUITS INTEGRES ET TRANSISTORS DE PUISSANCE. A brazing technique is described for providing a standard flat pack with a Thermkon base brazed to a Kovar frame through the utilization of an intermediary ring of high thermal conductivity material which prevents flashing onto the Thermkon base. Brazing is accomplished either in a one-step process in which the parts with the intermediary ring are brazed together all at one time with a single heat treatment, or in a two-step process in which the intermediary ring is first brazed to the frame. In a subsequent step, the frame with the intermediary ring brazed thereto, is brazed to the Thermkon base. In either process, the high thermal conductivity of the intermediary ring permits the ring to quickly reach brazing temperature for minimizing flashing.