METHOD TO MANUFACTURE FLANGES Russian patent published in 2011 - IPC H01L21/48 

FIELD: electricity.

SUBSTANCE: when making a flange of a body of a powerful SHF transistor from a pseudoalloy of copper-molybdenum during cutting the flanges are aligned relative to the direction of pseudoalloy MD-40 sheet rolling so that the long side of the flange is parallel to direction of rolling. As a result of anisotropy the coefficient of thermal linear expansion along the flange is within the range of 7.6÷8.4×10^-6 1/°C, which corresponds to the coefficient of thermal linear expansion of beryllium ceramics 7.6×10^-6 1/°C, which is soldered over the flange. The coefficient of thermal linear expansion across the flange makes 9.1÷9.9×10^-6 1/°C. Since the length of the flange considerably exceeds its width, the non-compliance of the coefficient of thermal linear expansion of the pseudoalloy and ceramics is concentrated exclusively on small transverse dimensions, as a result of which the bending of flanges in process of bodies soldering and operation of transistors is not available.

EFFECT: elimination of bending in flanges made from the pseudoalloy of copper and molybdenum, which occurs in process of bodies soldering with high-temperature solder; provision of contact in the whole area of flanges with heat removal for increase of power parameters and reliability of transistors.

3 dwg, 1 tbl