Virtual prototype of a low-cost vacuum baffle based on thermoelectric cooling

Abstract

Contaminants can enter vacuum systems from two main sources: backstreaming of oil vapors from the diffusion and mechanical pumps, and vapors generated as byproducts in the process chamber. Both sources can be hindered by using an appropriate baffle. We developed a virtual prototype of a low-cost baffle for vacuum systems that is cooled down with thermoelectric coolers (TECs). Compared to compressor cooling systems, TECs have useful advantages for this application: they are compact, silent, vibration-free, almost maintenance-free, inexpensive, widely commercially available, and capable of providing a precise temperature control. The baffle is partly built inside a tee vacuum fitting. A refrigerated cooper helix provides the trapping surfaces for contaminants flowing between the process chamber and the vacuum pumps. The cost of the baffle is below USD 250. The proof-of-concept model, implemented by the finite element method, showed that, when using TEC1-12706 modules, the helix can reach temperatures as low as −50 °C. According to our analysis, this temperature is more than enough for trapping the contaminants described above.