Clamping device for seed crystals - during single crystal growth by the Czochralski method

摘要

Appts. for drawing single crystals includes a drive rod attached to a seed crystal by means of a termination consisting of a cylindrical body bored square at one end and having a circular bore hole at the other end. The circular bore is made in two sections with a smaller bore portion adjacent the square bore portion and a large bore portion extending to the end of the termination. The drive rod is fashioned to watch the circular bore part and the seed crystal is made square to fit slidingly in the square bore part. Holes perpendicular to the axis are drilled in the cylindrical body and passing into the drive rod and also in the square section seed crystal. Fixing pins are then driven into the mating holes to hold the seed crystal and the drive rod in place firmly wrt the termination cylinder. The termination doe snot have to take into account differences of thermal expansion coefft. It can be made entirely in refractory material rather than expensive precious metals as in prior art.