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Solvent Alternatives Guide
CO2 Snow

General Information

  • CO2 snow cleaning uses "snow" particles formed from CO2 gas.

  • The process is effective for particle removal. Some success has been reported in removing finger prints and flux residue.

  • The exact removal mechanism is not completely understood. Some sources believe it is a weak blasting process in which the kinetic energy of the traveling snow flake removes particles. Other sources believe that there is a phase transition of the snow flake as it travels over a surface, which is actually removing the particle.

  • CO2 snow cleaning is more suitable for the higher cleanliness levels.

  • It may be a good option for particle removal, and possibly thin fluid removal, on delicate surfaces such as optical components and thin-film mirrors.

  • The equipment required is fairly simple:

    • A source of CO2 gas
    • A gas purifier (optional)
    • A proprietary "snow" gun.

  • The "snow" gun can be mounted in a controller for automated processes. One version has been designed to clean small (less than 0.25-inch diameter) blind holes.

  • Welding grade CO2 can be used if it is processed through a purifier.

  • This process can introduce a certain amount of contaminant, depending on the purity of the CO2 gas. This is usually not a problem except for the highest semiconductor cleanliness levels.

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Last Update: 18 March 1995