As we move forward in an ever more tech-focused era, microelectronics technology is more pervasive, and has become an essential across varying industries. Life sciences and medical research have adopted microelectronics to help progress new ways of observing and treating an increasing number of injuries and conditions. For example, implantable medical devices are now routinely used in treatment.
As part of the process in creating such devices, companies are often required to have specific skills and qualifications before a medical device manufacturer will allow production.
Sterilisation should be viewed as an 'essential but not quite enough’ measure
The requirements are generally to check that a company has the necessary experience in medical device manufacturing and the right kind of equipment needed for fulfilment. Another is to check if there are any required qualifications for staff or specialist training needed. And finally, to ensure all certifications and standards are up to date. However, another aspect that may be considered critical by a manufacturer of medical microelectronics is the use of a cleanroom.
Cleanrooms in microelectronics
Anywhere that produces products or follows processes which are sensitive to environmental contamination will have or have use of a cleanroom. Semiconductor manufacturing, biotechnology and the life sciences would all use a one, and even food production uses certain them to a degree.
A common misconception is that a cleanroom cleans things - which it does not. A cleanroom (or other such controlled environment) is an enclosed environment designed to control the concentration of airborne particulates, such as dust or chemical vapours. Cleanrooms are highly monitored and can only ever be as clean as the things inside them. The facilities, the staff, tools being used, cleaning chemicals and the product itself that is being manufactured, all present a contamination risk and so all potential risks must be tightly controlled.
The air that enters a cleanroom is firstly filtered to eliminate dust and once inside, it is then continually recirculated through a High-Efficiency Particulate Air (HEPA) and/or Ultra- Low Penetration Air (ULPA) filter to remove any particulate contaminants that may have been generated inside the cleanroom itself.
Microbial control is essential for implantable aids inside the human body
Going back to the microelectronics in medicine example used above, for devices designed to be used as implantable aids inside the human body, the use of an in-house cleanroom to control the microbial level (which can also be described as 'bioburden') during the last stages of product assembly is critical to avoid exposing individuals to danger.
Bioburden refers to the number of contaminating bacteria on a certain amount of material before it is sterilised. Although implantable medical devices are always thoroughly sterilised, this step should be viewed as an 'essential but not quite enough' measure. While sterilisation would kill any living bacteria on a device or even the packaging, pyrogenic (infection/fever-causing) substances could still be present, which presents an intolerable risk to a potential patient. The use of a microbial- controlled cleanroom allows medical device manufacturers to ensure the complete process is low risk and uncontaminated.
By eradicating the need to ship finished devices to a third-party company for treating or packaging prior to the sterilisation stage, in house cleanrooms also help to shorten the supply line, eliminating the need for an extra step and reducing risk of external contamination.
Regulatory standards
All cleanroom facilities designed for pharmaceutical development or types of manufacturing, including microelectronics, need to conform to the standards for controlled environments.
The standards that are used are cGMP (Current Good Manufacturing Process) and/or ISO 14664.
It is essential as a facility owner that standards are adhered to and maintained, in order to control contamination and ensure the safety of the working environment. All cleanroom facilities have a classification which is determined by the concentration of airborne particles, ranging from 0.1 μm to 5 μm (see diagram 1). The classification of individual facilities will vary, depending upon its use.
An independent servicing company, such as Crowthorne Group, can advise on Cleanroom classification and any individual variations on standards that a Cleanroom is required to meet to maintain compliance. The frequency of which cleanrooms need to be serviced and the types of tests that need to be conducted can also be advised upon
