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.