Slim rod production

The cost reduction potential and the high technical flexibility of in-house production led to the decision of producing slim rods ourselves. Since commercial equipment resulted in high costs a new concept was developed that has the following features:

  • Starting with feed material produced by our Siemens-reactors.
  • Continuous pulling from the melt, allowing high flexibility for different length.
  • Bridge joints by welding.
  • High mechanical strength of rods compared to rods cut by OD-saw.

The existing slim rod puller is described as follows:

  • Slim rod puller consists of two separate recipients and two high frequency generators as energy source.
  • Si-feedstock rod is melted in the top region.
  • 4 or 6 slim rods can be pulled simultaneously.
  • Option: In-line doping to get appropriate dopant level of the slim rods.
  • Design parameter:
    • 6 simultaneously pulled slim rods with diameter of  8 ± 0,5 mm.
    • Target length up to 3,500 mm.

For this innovative process a patent has been granted.