Next Trade Shows
Photonics West and BISO ,San Francisco, Feb 2020
NESF Astronomy April 2020
American Institute of Art Conservation Salt Lake City May 2020
SPIE Optics and Astronomy Yokohama, June 2020
Optics and Photonics August 2020
Amereican Vacuum Society Oct, 2020
Contact Us for literature on any of these shows.
The three most recent papers are
1 - 2007 - R. Sherman, Particulate Science and Technology Vol 25, p. 37-57, 2007. Carbon Dioxide Snow Cleaning. This is a review.
2 - 2010 - D. A. Chernoff and R. Sherman, J. Vac. Sci. Technol. Vol B 28, 2010 “Resurrecting dirty atomic force microscopy calibration standards” How to clean AFM samples, best shop note in JVST for 2010.
3 - 2016 - R. Sherman in Kohli, Rajiv, and Kashmiri L. Mittal, eds. Developments in Surface Contamination and Cleaning, Vol. 1: Fundamentals and Applied Aspects. William Andrew, 2015, p. 695 - 716
Recent Interesting Presentation:
CO2 Snow Cleaning at the American Art Museum Conservation Symposium. The entire day was devoted to talks on CO2 snow cleaning and pellet cleaning of art work. Three talks were on CO2 snow. The talks are at https://www.youtube.com/watch?v=MjyvjVAGe-k and https://www.youtube.com/watch?v=P4gOPpNgdWQ
We put efforts into making units dedicated for large telescope mirror cleaning and for cleaning art as in restoration and conversation. Please see those respective pages, Telescopes and Art Conservation. We also added a leak valve option.
Portable Units - We have two units with a small CO2 canister attached to the hand gun or solenoid. These canisters are less and 1/2 KG of CO2. They are totally portable, hand carried. The solenoid version can be equipped with batteries. These units are now easy to refill in any lab.
Dual Gas Units: We make a teflon insert that can fit over the nozzle and then nitrogen or dry compressed air passes over and about the cold CO2 stream. This design is based upon the ideas of Hoenig, 1986. This does not eliminate the moisture problems, but reduces it. The Dual Gas Unit (K6-10DG-A) uses 2 solenoid valves, one for the CO2 and another for the nitrogen flow. Solenoid controls can be footpetals or just 24VDC signals. The K6-10DG-B uses a valve in place of the second solenoid. A dry compressed air heater can be attached.
New Nozzles: We developed a few new nozzles with reduced consumption, flow and velocity, yet they still perform organic thin film and particle removal. By still having oganic removal, submicron particle removal will occur. The polymer nozzle is still available for existing customers at reduced prices. We also introduced a leak valve for reduced flow.
Automation: We offer automation abilities though we do not make automated systems. In conjunction with others, we can supply custom automation units. These machines can meet the needs of thin film, wafers, optics, relays, and many other manufacturing processes. We offer many arrangements, including a 4 axis movement (x,y,z, rotation), Class 10 environment and many other features. Email for information. Eco Snow makes dedicated CO2 Snow Cleaning systems for photomasks and semiconductors, email us for a contact.
Large Area Blaster - By using one of 3 tube diameters (range from 0.033 to 0.062) and a second expansion, this modified standard unit can remove residual particles from large areas quickly. This is aimed at telescope mirrors. We also offer 2" (5 cm) and 4" (10 cm) versions.
Methods and Applicatons
Sample preparartion for AFM is a growing area. See the AFM page for an example of removing 0.03 micron particles. CO2 Snow cleaning removes particle and organic residues and yields cleaner images and less tip artifacts. This is due to the removal of stray particles and "nanoscum". We think cleaning AFM tips is possible, we did it once and want a manufacturer to assist. Recent work on AFM samples strongly suggest that CO2 snow cleaning can remove particles down to 5 nanometers
One user tried a high purity SFC CO2 cylinder that had a He head space. The input pressure was at 1500 psi instead of the ususal 800 psi. They claim better cleaning over a larger area. A short working distance may give more liquid CO2 on the surface and greater particle and organic cleaning.
Cleaning parts for high vacuum and UHV have led some users to reduce solvent consumption and also yields cleaner srufaces for use in vacuum and also high voltage applications.
One user developed a simple and inexpensive way to clean wafers. Email for ideas.