Directional solidification furnace having movable heat exchangers

摘要

A directional solidification furnace includes one or more movable cooling plates disposed beneath a crucible. In a first position, the cooling plates are free from contact with a crucible support positioned adjacent the crucible. In a second position, the cooling plates are in contact with the crucible support. A control system is used to control the amount of force exerted by the cooling plates against the crucible.

主权项

1. A directional solidification furnace for producing a multi-crystalline silicon ingot, the furnace comprising:
a crucible for containing a silicon charge; a crucible support disposed adjacent the crucible for supporting the crucible, the crucible support having a base; a cooling plate positioned beneath the base of the crucible support and including a heat exchanger; a lift system for moving the cooling plate between a first position where the cooling plate is free from contact with the base of the crucible support and a second position where the cooling plate is in contact with the base of the crucible support, the lift system moving the cooling plate in a vertical direction, the lift system comprising an upper plate spaced apart from a lower plate and at least one spring positioned between the upper plate and the lower plate, the upper plate and the lower plate positioned beneath the cooling plate; and a control system to control the amount of force exerted in the vertical direction by the cooling plate on the base of the crucible support, wherein the at least one spring has a spring constant indicative of the stiffness of the spring, the at least one spring being compressed when the cooling plate is in the second position, wherein the lift system comprises a limit switch, the limit switch is operable to determine if the lower plate is spaced less than a set distance from the upper plate.