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Poster Session: Novel Airborne-Based Particle Measurement Methodologies

Novel Airborne-based particle measurement methodologies monitoring and control system for cleanroom and environmental Applications.

A clean, contamination-free work environment is critical to maximize yields, as certain particles are likely to cause defects, irregularities, inaccuracies, and even failures. Analyzing particle contaminants is an important step in having control over operating environments and reducing particle deposition in critical components. Isolating, characterizing, and understanding the types of particles found in products or processes can usually yield a likely source for the particles. Once the source is known then elimination of the particulate contamination becomes substantially easier.

This work analyzes emerging airborne-based particle testing methods that allow quick evaluation alternatives for cleanroom and controlled environments. Nondestructive options for the evaluation of cleanliness of parts and materials are currently available and these alternative methodologies have proven to be extremely attractive for the effective monitoring of parts and processes in controlled environments, they may eventually become the industry Recommended  Practice in the near future. Leading semiconductors, media manufacturers, and medical devices ( like new 3D printing  Swabs) have validated these methods and are currently developing their own testing procedures with new airborne-based technologies for non-destructive testing. 

In particular, this paper explores established and new technologies in particle counting and particle collection for identifying and characterizing contamination sources in controlled environments.  Analysis of technologies, procedures, and potential applications are presented and alternatives to existing technologies – such as liquid particle counters(LPC) – are discussed. In addition, this paper explores the limitations and benefits of size-channel based particle counters vs. continuous particle size spectrum analysis for identifying contamination sources. The latter complements the acquisition and collection methods discussed here, by adding valuable information. The latter provides an integrated methodology for monitoring environments and parts.

Tests show that airborne-based particle monitoring of parts is significantly faster (1 to 5 minutes of total testing time) when compared to LPC-based methods. In some cases, airborne monitoring does not exhibit the limitations commonly associated with liquid methods, allowing nondestructive testing. It also enables the monitoring of additional items that cannot be tested with LPC, such as graphite parts, medical devices, assemblies, and consumables. Add these technologies as based on airborne measurements, they can detect dissolvable solids, which are invisible to LPC, and parts may be tested in working condition. 

Extensive analysis can be performed for characterizing airborne particulate matter by collecting particles on an impact plate for direct analysis with scanning electron microscopy while maintaining the real-time analysis capabilities of a particle counter.

New technologies show a promising future for particle monitoring and control systems based on airborne particles non-destructive testing in various materials, parts, and assemblies.  They require relatively short preparation to obtain results in a fraction of time and can report particle sizes from nanometers to micrometer. In addition. These technologies report particle count evolution as a function of time and allow real-time particle collection for SEM/EDX or XRF.



Yitzhak Vanek

Engineering and Senior Manager, Persys Group