Patent ID: 8236596

Claim:
A continuous conveyor diffusion furnace for processing solar cell wafers, comprising in operative combination: a) a plurality of heating and cooling zones oriented in sequence from a furnace inlet to a furnace outlet, said zones being disposed in abutting relationship to define there-through a continuous longitudinal processing conveyor path oriented in a generally horizontal plane; b) a low-mass conveyor system for receiving and moving solar cell wafers along said longitudinal processing path from said furnace inlet to said furnace outlet through said zones, said conveyor system comprising: i) a plurality of spaced apart, high temperature resistant, metallic wires oriented transverse said to said longitudinal processing path, said wires having a length defining a useful wafer transport width of said conveyor system through said furnace zones; ii) small diameter, thin walled, non-rotating refractory tubes suspended on said wires to provide support for said wafers as they are transported through said furnace zones by said conveyor system and to substantially completely shield said wafers from metallic vapors de-gassing from said wires; iii) said refractory tubes extending at least a substantial portion of the length of said wires and positioned on said wires to leave exposed only short opposed side ends of said wires; iv) a pair of spaced-apart transport members, one disposed adjacent each end of said wires, each of said transport members forming a continuous loop through said longitudinal processing path from furnace inlet to said furnace outlet, and thence on a return path outside said furnace zones back to said inlet; v) each of said transport members include a plurality of receiving members spaced uniformly along each of said transport member continuous loop, each said receiving member is configured to removably retain said short, side end of said wire disposed suspended between said transport members across said transport width; and c) a drive system disposed outside said furnace zones disposed to engage both said transport members for synchronous movement through said zones as said transport members carry said plurality of refractory tubes and wires suspended between said receiving members, on which refractory tubes said wafers are transported through said zones during furnace operation to process them.