Patent DE-102009002792-A1 (DE)
Title: Method for the production of crystalline form body from melt, comprises carrying out manipulation of correcting variable for influencing control variable in breeding process, where a regulation is carried out in a control circuit
Inventor: NEUBERT MICHAEL
IPC: C30B15/20
Filed: 2009-05-04
Abstract: The method for the production of crystalline form body from melt, comprises carrying out manipulation of correcting variable for influencing control variable in breeding process, where a regulation is carried out in a control circuit over a proportional-integral-derivative (PID) controller (1.1, 2.1) with predeterminable control algorithm or the regulation is carried out in the control circuit over PID-controller and a model-based controller (2). The manipulation and regulation of the correcting- and control variable in the control circuit by identification number of system-reaction-number. The method for the production of crystalline form body from melt, comprises carrying out manipulation of correcting variable for influencing control variable in breeding process, where a regulation is carried out in a control circuit over a proportional-integral-derivative (PID) controller (1.1, 2.1) with predeterminable control algorithm or the regulation is carried out in the control circuit over PID-controller and a model-based controller (2). The manipulation and regulation of the correcting- and control variable in the control circuit by an identification number of a system-reaction-number describing the thermal behavior of the breeding process, in which the system-reaction-number is introduced in the control algorithm of the PID-regulator. The manipulated variables of drawing speed, the heating performance and/or the heating temperature are manipulated and the control variable of crystal growth rate, crystal radius and/or displacement ratio are regulated. The regulation is carried out in two control circuits with PID-controller. The crystal radius is regulated in correcting variable in the first control circuit over the manipulation of the drawing speed. The actual drawing speed on the basis of a deviation of actual crystal radius is experimentally determined from a desired-crystal radius. The regulation coefficient of the PID-controller and a nominal system reaction-number are determined as first input quantity and/or the system-reaction-number as a second input quantity of the PID-controller. The breeding process is carried out in second control circuit, where the growth speed is controlled over the manipulation of the heating power. The crystal radius is regulated in a second regulation variant in the first control circuit over the manipulation of the drawing speed. The actual heating power on the basis of a deviation of actual crystal radius is experimentally determined from a desired-crystal radius. The system-reaction-number is calculated from a material specific classification number, a phase boundary mobility and/or a temperature gradient in crystal directly to the phase boundary and the actual- or desired growth rate. The phase boundary mobility is calculated from the parameters such as thermal conductivity of the crystals, density of the crystals and specific latent heat. The system-reaction-number is introduced for weighting of P-, I-, and D-coefficient of the PID-controller in the control algorithm. The system-reaction-number is constantly held during the breeding process. The crystal radius is resolved in the first control circuit through manipulation of drawing speed or heating power over weighing of control coefficient of the PID-controller and the growth rate in the second control circuit is resolved through the manipulation of the heating power or drawing speed over weighting of the control coefficient of the PID-controller. An independent claim is included for an arrangement for the production of crystalline form body from melt.