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.