Process for the production of semiconductor rectifiers

Claim 1

IN THE PROCESS FOR THE PRODUCTION OF A SEMICONDUCTOR RECTIFIER ACCORDING TO THE ALLOY PROCESS, ACCORDING TO WHICH A COATING SUBSTANCE IS APPLIED TO A SUBSTANTIALLY PLANE FACE OF A SEMICONDUCTOR BODY AND IS ALLOYED WITH THE LATER BY THERMAL TREATMENT, THE IMPROVED TECHNIQUE WHICH CONSISTS ESSENTIALLY IN THE STEPS OF DISPOSING THE SEMICONDUCTOR BODY IN A MOLD WITH THAT FACE THEREOF TO WHCIH THE COATING SUBSTANCE IS TO BE APPLIED BEING UPPERMOST, SAID MOLD FORMING TOGETHER WITH SAID BODY A CLOSED SPACE OF WHICH SAID PLANE FACE OF SAID SEMICONDUCTOR BODY CONSTITUTES THE BOTTOM WALL, DISPOSING IN A TUBULAR EXTENSION OF SAID CLOSED SPACE ABOVE AND SUBSTANTIALLY SPACED FROM SAID UPPERMOST PLANE FACE OF SAID SEMICONDUCTOR BODY A COLUMNAR MASS OF SAID COATING SUBSTANCE IN SOLID FORM, FREEING SAID CLOSED SPACE FROM OXYGEN MAINTAINING THE SEMICONDUCTOR BODY AT AN ELEVATED TEMPERATURE ABOVE THE MELTING POINT OF THE COATING SUBSTANCE BUT BELOW THE TEMPERATURE RANGE IN WHICH ALLOYING BETWEEN SEMICONDUCTOR BODY AND COATING SUBSTANCE TAKES PLACE TO ANY CONSIDERABLE EXTENT, APPLYING HEAT TO THE COLUMNAR MASS OF COATING SUBSTANCE IN SUCH MANNER THAT THE UPPER PART OF SAID MASS BECOMES MOLTEN WHILST THE LOWERMOST PART IS STILL SOLID AND FINALLY MELTING SAID LOWERMOST PART THEREBY SUDDENLY DROPPING THE MELT OF COATING SUBSTANCE OUT OF SAID TUBULAR EXTENSION AND ONTO SAID UPPERMOST FACE OF SAID SEMICONDUCTOR BODY WHEREBY IMPURITIES OF THE COATING SUBSTANCE IN THE TUBULAR EXTENSION ARE SEGREGATED BY THEIR ADHERENCE TO THE WALLS OF SAID EXTENSION, SO THAT SAID MOLTED COATING SUBSTANCE SPREADS OUT AS A THIN-LAYER COVERING SAID PLANE FACE, AND THEREAFTER FURTHER HEATING THE SO-COVERED SEMICONDUCTOR BODY TO ALLOYING TEMPERATURE, THEREBY EFFECTING THE FORMATION AND PROGRESS OF A PLANE ALLOYING FROM WHICH REMAINS PARALLEL TO SAID PLANE FACE.