Micro-Contamination & Clean Room Science

Many products require manufacturing in a cleanroom or controlled environment. The science of micro-contamination and cleanrooms is important for yield and reliability of these products. One type of product that requires cleanrooms for manufacturing is semiconductors. In addition, LCDs, batteries, medical devices, MEMS, nanotechnology products, pharmaceuticals, optical devices, device packaging, disk drives, consumer electronics assemblies, and even food processing are all examples of products that require a high level of cleanliness in the manufacturing environment.

Exponent provides a variety of services related to micro-contamination and cleanroom science:

  • Contamination identification 
  • Cleanroom auditing 
  • Training 
  • HVAC support 
  • Corrosion assessment 
  • Environmental evaluation 
  • Testing
As geometries get smaller, contamination issues increase, so evaluation and elimination become critical in a manufacturing setting. With smaller contacts on printed-circuit boards it will take even less surface contamination to cause a contact resistance problem. Consumer electronics, nano-technology, semiconductor components, and MEMS fail in the field due to microcontamination. Contaminants on printed-circuit board assemblies can result in failures due to electrochemical migration and corrosion. Exponent engineers and scientists assist clients to identify the contaminant, tie it to a root cause, and eliminate any potential problem that is critical to the continued success of the client’s business. 

Operation of computers inside controlled environments is required for high-reliability computer servers and computer rooms. The control of temperature, relative humidity, and air quality for a computer installation is critical for reliability of the equipment; increased relative humidity can result in corrosion failures. Decreased relative humidity increases the probability of electro-static discharge failure. Identification of these problems and elimination of further failure is a service that Exponent provides. 

Our capabilities in micro-contamination and cleanroom science enable us to measure particulate size distributions, airborne molecular contamination, surface chemical contamination, air velocity, temperature, and relative humidity. For instance, HEPA filter breakthrough can occur but won’t be identified unless the proper measurement tools and techniques are used. Our expertise includes identification of contaminant sources through chemical analysis. 

The cost of cleanliness can be reduced with a properly placed mini-environment or modular cleanroom or laminar flow hood. The traditional ballroom cleanroom is no longer the only choice in facilities—high-performance, lower cost solutions are available, yet experienced personnel must be involved in the process for success. Materials of construction in the cleanroom are important, because they can contribute to contamination if appropriate materials are not chosen. Shedding and outgassing are problematic to many product types in manufacturing. Our scientists have over 20 years expertise in identifying problems in manufacturing environments, and we bring that knowledge to bear in helping our clients realize substantial savings through yield improvements and facilities maintenance. We have HVAC expertise and provide support in chemical filtration, airflow modeling, identification of approved cleanroom materials, tooling, and low-outgassing materials of construction. 

Our staff provides facility audits, performs measurements on critical processes, trains personnel in protocol and proper product handling, and identifies vendors and appropriate products for cleanliness requirements, which can include consumables (gowns, wipes, gloves, etc.), benches, furniture, feedthroughs, and mini-environments. Our inspection services include set up and implementation of particle, airborne, and surface contamination source identification and elimination, line partition methodologies, and identification of automated equipment for defect inspection. We write procedures and set up self-audits for continuous improvement. We inspect to a variety of specifications, including the new ISO-14644 series.