METHODS TO BOND SILICA PARTS
A method of bonding a first silica part to a second silica part includes coating contacting surfaces of the first and second silica parts with a solution having one of silica and silica precursors. The coated surfaces of the first silica part are placed adjacent to the coated surfaces of the second silica part to form an assembly, and the assembly is heated.
1 . A method of bonding a first silica part to a second silica part, the method comprising:
providing the first silica part;
providing the second silica part;
coating contacting surfaces of the first silica part and second silica part with a solution having at least one of silica and silica precursors;
placing the coated surfaces of the first silica part adjacent to the coated surfaces of the second silica part to form an assembly; and
heating the assembly.
2 . The method of claim 1 , wherein heating the assembly occurs in an inert atmosphere.
3 . The method of claim 2 , wherein the inert atmosphere is substantially argon.
4 . The method of claim 1 , wherein heating the assembly is performed in a range of about 1150° C. to about 1550° C.
5 . The method of claim 1 , wherein heating the assembly is performed for between about 4 hours and about 16 hours.
6 . The method of claim 1 , wherein the solution includes a silica precursor, the silica precursor is tetroalkoxysilane.
7 . A crucible for use in directional solidification of multicrystalline ingots, the crucible comprising:
a base;
a sidewall extending around the base to form a vessel for the containment of material therein; and
a weir attached to the base at a location inward from the sidewall to define an inner cavity and an outer cavity, the weir having at least one passage therethrough to allow material in the outer cavity to be moved into the inner cavity.
8 . The crucible of claim 7 , wherein the weir is attached to the base with a bonding agent selected from one of a silica and a silica precursor.
9 . The crucible of claim 7 , wherein the bonding agent is selected from one of Cab-O-Sil, Thermosil, and tetroalkoxysilane.
10 . The crucible of claim 7 , further comprising a second weir located inward from the sidewall.
11 . A system for growing a single crystal ingot, the system comprising:
a crucible having:
a base;
a sidewall extending about the base to form a vessel for the containment of material therein; and
a weir affixed to the base at a location inward from the sidewall to define an inner cavity and an outer cavity, the weir has at least one passage therethrough to allow material in the outer cavity to be moved into the inner cavity;
a heater located adjacent to the crucible for supplying heat to the crucible to maintain the melt material contained therein; and
a feed tube connected with the crucible for supplying a feedstock material to the crucible.
12 . The system of claim 10 , further comprising a computing device for controlling the feed rate of the feedstock material through the feed tube.
13 . The system of claim 10 , further comprising a puller system for lowering and raising a seed crystal into and out of the silicon melt.
14 . The system of claim 10 , further comprising a controller for adjusting the amount of heat provided by the heater to the crucible.
15 . The system of claim 10 , wherein the crucible includes a second weir located inward from the sidewall.
16 . A method for growing a single crystal ingot from a crucible having a base and a sidewall and a weir affixed to the base at a location inward from the sidewall to define an inner cavity and an outer cavity, the weir having at least one passage therethrough to allow material in the outer cavity to be moved into the inner cavity, the method comprising:
placing a feedstock material into the crucible;
melting the feedstock material to form a melt that passes through the passage from the outer cavity to the inner cavity;
lowering a seed crystal into the melt; and
pulling the seed crystal from the melt to pull an ingot from the seed crystal.
17 . The method of claim 14 , wherein the feedstock material is placed into the crucible at a location radially outward from the weir.
18 . The method of claim 14 , further comprising measuring a temperature of the melt at a location immediately adjacent the growing ingot.
19 . The method of claim 14 , wherein the ingot is pulled simultaneously with placing the feedstock material into the crucible.