Assessment and selection of ultraprecision cleaning technologies

Cleaning processes are a key technology to achieve, restore and guarantee specified product cleanliness requirements in all contamination critical industries, spanning the semiconductor industry, through the automotive and aerospace industry right up to life science branches, such as pharmaceuticals, food and medical device technology. Depending on application and product, different contaminants can be critical, e.g particulate contamination, molecular contamination as well as microbiological contamination. Although the type and specified amount of contaminants vary from one product and industry to the next, the crucial question in regard of the selection of suitable cleaning processes remains the same: To what extent can a state of cleanliness be improved by using a certain cleaning technology? However, less knowledge is available in regard of the efficacies of the available cleaning technologies to select the most feasible process for a specific cleaning task. This gap is currently closed by two standards: the aerospace standard ECSS-Q-ST-70-54C (»Ultracleaning of Flight Hardware«) and the ISO/DIS 14644-13 (»Cleaning of surfaces to achieve defined levels of cleanliness in terms of particle and chemical classifications«).