100 Indel Avenue
P.O. Box 156
Rancocas, NJ 08073
Ph.: +1(609) 267-8000
Consarc, an Inductotherm Group Company, has developed
new Electromagnetic Cold Crucible (EMCC) furnace technology
for producing multicrystalline silicon ingots at a fraction of the
cost of traditional Directional Solidification (DS) furnaces.
Electromagnetic Cold Crucible (EMCC) is an innovative
process utilizing a segmented water-cooled copper crucible
for refractory-free induction melting, while under vacuum or
controlled atmosphere. Melting in a water-cooled copper
crucible eliminates the possibilityof contamination from the
fused silica solar crucible.
The copper crucible is made up of water-cooled segments
or “fingers.” The magnetic field produced by the coil, in
effect, passes through the crucible to induce heat into the
silicon. The magnetic field also intensely stirs the liquid
pool and promotes a very homogeneous melt.
Since 1985, Consarc has continuously strived to improve, develop and refine the EMCC Technology to increase its efficiency. We developed correlations between materials melted and power levels, frequencies and crucible diameters. Consarc has pioneered new manufacturing techniques for EMCC crucibles, and as a result has increased crucible life by orders of magnitude.
NON-CONSUMABLE/NON-CONTAMINATION CRUCIBLE DESIGN
Consarc’s water cooled segmented copper crucible is designed for multiple heats compared to the one time use of a fused silica solar crucible in a traditional DS furnace. Another major advantage of the EMCC furnace is that the silicon melt is levitated off the water cooled
walls of the crucible, thus avoiding contamination of the molten silicon.
INCREASE PRODUCTION RATE
Typical growth rate of silicon ingots in a traditional DS furnace is 10-20 mm/hr. The EMCC growth rate is greater than 70 mm/hr dependent on the withdraw speed. Another advantage of the EMCC furnace is the increased usable yield from the silicon ingot compared to the average yield achieved in a traditional DS furnace.
Reduced Capital Cost
The EMCC furnace will displace a number of traditional DS furnaces; savings will be achieved with a reduction in factory space and high equipment consumption.
Reduced Operational Cost
• Less man power requirements
• Shorter cycle times
• Crucible is reusable