Silicom's efforts in numerical simulations support manufacturing of massive sapphire boules for mobile cover screens and energy-efficient LED lighting

Silicom has developed an open-source simulation tool for the growth of large-scale sapphire boules. The tool, based on Elmer software (, is capable of simulating critical phases of sapphire growth, like seed-melting, controlled growth and cooling.

"Silicom has been priviledged to develop the tool in close collaboration with customers, who are the leading players in production of massive sapphire boules", said Dr. Jari Järvinen, founder of Silicom. "Our current tool is validated against experiments in HEM, and we look forward to our joint efforts to optimize sapphire growth and reach remarkable cost-savings with simulations."

The tool, developed by Silicom, is capable of simulating axi-symmetric and transient seed-melting, crystal growth and cooling on growth-recipe basis. The tool includes heat transfer by radiation (opaque and transparent materials), conduction and convection (melt flow, gas flow), phase-change between crystal and melt, and gas convections. The crystal-melt interface is tracked in fixed-grid, giving a superior position compared to moving grid alternatives.