Rochester, NY—Linton Crystal Technologies (LCT) has been awarded a U.S. Letters Patent for its Seed Lifting and Rotating System for Use in Crystal Growth. Patent 11,255,024 is the first of four applications Linton has made to the USPTO for innovations related to the seed lifting and rotating mechanism, and the company’s first approved patent.
“This patent is the first of four applications that address the increasingly critical need to counteract centrifugal forces created by the rotating mass of the seed lift as the cable spool translates along its axis of travel. As growers become larger, the need for this technology becomes even more essential” John Reese, mechanical engineering manager with Linton Crystal Technologies.
Typically, silicon crystal growing furnaces use a cable winch system to lift and rotate a growing crystal. Most traditional seed lift mechanisms have a grooved spool that wraps and gathers the seed cable, lifting the crystal. The spool must translate side to side to keep the gathering cable centered to a pulley, which in turn is centered on the growth chambers. Most often, the spool moves this way via an attached thread that engages to a nut. As the bolt turns into the nut in its fixed position, the head of the bolt becomes closer to the nut. In the case of a seed lift spool, the length of the screw depends on the length of translation that is necessary to wind and/or unwind the cable enough to grow the crystal to a desired length. Thus, the length of the screw increases the overall length of the cable winch system. This adds size and weight to the overall system.
As the spools shifts/translates from one end of its travel to the other, the shifting mass of the spool dramatically and negatively influences the dynamic balance of the rotating seed lift assembly, thus creating centrifugal forces that have a negative impact on the stability of the overall growth process.
Linton’s patented new “guided spool” design utilizes a floating roller that engages with the grooved spool, therefore eliminating the need for the extra threaded feature and fixed position nut. This reduces the overall weight of the mechanism, making for a more stable rotating mass. Current units that don’t have this feature require additional fixed and active weight to balance them.
Linton is the world leader in the design, development and manufacture of equipment for producing monocrystalline ingots for the solar and semiconductor industries. The company specializes in silicon and produces equipment for materials such as germanium and gallium arsenide. They also provide technical support, process engineering support and replacement parts to help clients get businesses off the ground, improve productivity and continue to innovate. Linton has been the exclusive owner of Kayex technology for eight years.