Venesia Hurtubise, technical chemist at MicroCare Corporation, writes about the importance of incorporating a process to ensure medical electronics work as they should, including how vapour degreasing is making a difference when manufacturing medical electronics.
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Microchip production factory.
The role of electronic medical devices is rapidly changing as more advanced technology is designed and developed. This shift is transforming healthcare particularly in areas like diagnostics and remote patient monitoring as medical management moves outside the hospital setting and into the home. This trend is likely to continue as ever more patients are being remotely diagnosed, treated and monitored due to the COVID-19 pandemic.
More investments are being made in innovative, electronic technology like handheld ultrasound systems and digital stethoscopes as well as pioneering remote patient tracking equipment. An increase in these technological advancements is driving the growth of the medical electronics market. It was valued at $3.01 billion in 2015 and is expected to reach $4.41 billion by 2022.
This accelerating growth and scientific advancement calls for maintainable and reliable manufacturing, with the assurance that devices will work effectively and consistently. A recognised method to help guarantee reliability is through quality cleaning. Improved cleaning directly translates to more effective printed circuit boards (PCBs), and therefore to better medical electronics.
What is important, is finding a cleaning solution that lasts the distance in terms of sustainability, reliability and cost-effectiveness. Almost all medical devices require cleaning during manufacture to remove particulate, flux, oils or inorganic contamination resulting from the manufacturing process. The smallest contaminant can form a barrier between electrical contacts. Dirty printed circuit board assemblies (PCBAs) are susceptible to a whole host of problems ranging from electrochemical migration and delamination to parasitic leakage, dendrite growth and shorting. It is this reason why cleaning is crucial to ensuring the consistency of an electronic medical device.
The challenge is to identify a process that is suitable for the critical cleaning of complex assemblies, intricate shapes and delicate parts, and also meet evolving environmental and worker safety regulations.
Regulation rules
Electronic components used within medical devices require not just long-term functionality, but they must also stand up to rigorous regulations put in place by governing bodies.
Medical electronics often include dense circuitry within very small, complex packages. These devices have to pass extremely stringent tests and be free from contamination to be used inside the body. A prime example of this is implantable devices like pacemakers, defibrillators and cochlear implants. Reliability is non-negotiable as it can come down to a matter of life or death if the device was to fail. It is not only necessary for implantable electronics, but also for external devices where accuracy is essential to diagnosis.
There are several different regulations to adhere to, for example those stipulated by the Food and Drug Administration (FDA) which look at points like toxicity and sterility, or International Standards Organization (ISO) which identifies quality management processes.
Another example is the benchmark standard IEC 60601-1. Specified by the International Electrotechnical Commission (IEC) this regulation is explicitly designed for medical electrical equipment and systems. It necessitates that the basic safety and essential performance of the medical device be maintained. Cleaning is one of the central practices to help to meet this requirement.
Not only is cleaning required to meet regulatory and reliability requirements, but the fluids used for cleaning also have guidelines to follow. Some of the biggest challenges when cleaning medical electronic devices include environmental and worker safety concerns. There are very specific sustainability regulations that must be met. An obvious example is the Montreal Protocol, an international agreement that regulates the production and consumption of man-made chemicals which contain ozone depleting substances (ODS).
This protocol came into effect in 1987 listing nearly 100 ODS that threatened human health by lessening the earth’s protective stratospheric ozone layer. Some ODS are strictly controlled for their use, others are targeted for phasedown, with some completely phased out.
The Montreal Protocol’s Scientific Assessment Panel estimates that with implementation of the treaty we can expect near complete recovery of the ozone layer by the middle of the 21st century. This highlights its significance and why it is important to find and use sustainable cleaning methods.
Sustainable cleaning
The processes and cleaning fluids used in the development and manufacture of medical electronics must be precise and consistent. However, it is not enough for companies to just produce high quality parts. They must also minimise negative environmental impact, conserve energy and protect natural resources all while ensuring the health and well-being of their employees
Vapour degreasing, when used with advanced cleaning fluids, is playing an important role in meeting this sustainability challenge. It is being more widely utilised within the medical electronics sector because it complies with the rising number of environmental laws regulating cleaning fluid use and worker safety.
The Montreal Protocol is just one of a growing number of regulatory conditions that are working to reduce any negative impact to the planet and its people. Cleaning fluids that were once used to clean electronics parts are now being phased out or have been banned completely. In the US, the Environmental Protection Agency (EPA) has added TCE, Perc and nPB to the watch list. The EU’s rules of Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) currently classifies TCE as a carcinogen with nPB soon needing special permission for use in Europe after July 2020. Furthermore, Canada and Japan are severely restricting, or have banned, these solvents altogether. For this reason it is prudent to seek the most sustainable long-term cleaning solutions.
Modern cleaning fluids used in a vapour degreaser have outstanding ecological and safety credentials. They are non-toxic, environmentally-friendly and highly effective cleaning options that perform better than older hazardous solvents.
Highly advanced cleaning fluids have been developed to replace harmful chemicals like HCFC-225 or nPB and TCE, which have air and ground water quality concerns. The new fluids are not only effective at thoroughly cleaning components, but they stand up to the regulatory requirements of the medical industry and international governing bodies.
These new progressive cleaning fluids benefit from being ozone-safe and meet standards like those required by the EPA or REACH. Additionally, they are approved under the U.S. Significant New Alternatives Program (SNAP) and Toxic Substance Control Act (TSCA). They feature a minimal Ozone Deleting Potential (ODP) and a low Global Warming Potential (GWP).
What is important is that they offer improved environmental properties without compromising on performance.
Working safely
When looking for sustainable long-term cleaning strategies consideration must also be given to protecting workers’ health and safety. The PEL (Permissible Exposure Limit) or OSHA-designated time limit that workers should be exposed to a chemical is much better for sustainable cleaning fluids than older legacy solvents. Typical permissible exposure levels for sustainable fluids are 200-250 ppm. Compared with TCE which has a 100-ppm PEL or nPB which is rated at just 0.1 ppm by the American Conference of Governmental Industrial Hygienists. Modern cleaning fluids are considerably better for the safety of exposed workers and help in preserving air quality, a significant benefit for workers.
In addition to protecting air quality by producing fewer emissions, sustainable cleaning fluids offer a further safety advantage thanks to it being non-flammable. This is important in lowering the environmental health and safety risk and protecting workers from accidents.
Cleaning without compromise
There is no compromise when it comes to cleaning medical electronic devices. It has to combine exceptional cleaning, and also address regulatory requirements. Vapor degreasing, when used with modern cleaning fluids, offers an answer to this challenge.
Vapour degreasing is a simple process that is effective at removing contaminants. The low viscosity and surface tension ratings of modern cleaning fluids, combined with their volatility, allow them to clean very effectively even in small crevices and areas that other cleaning options cannot easily infiltrate. This ensures that all the surfaces of the finished component will be effectively cleaned, even under tight-stand-off components.
Environmentally-progressive cleaning fluids also have the benefit of reducing the risk of bioburden – critical when it comes to medical devices. Since vapour degreasing fluids contain no water there is no threat of bacteria growth. When parts are cleaned using a modern cleaning fluid inside a vapour degreaser, the parts exit the machine immediately dry, further eliminating the risk of bioburden and helping to meet the criteria needed for process validation.
Today’s vapour degreasing cleaning fluids are effective at thoroughly removing contamination from medical electronic devices while standing up to the regulatory requirements of the medical industry. Formulations are now cleaner, greener and safer. They are the most sustainable and progressive way to clean and help to maintain the reliability of medical electronic devices.
For help in determining what cleaning fluid to use for your particular medical devices and types of contamination, it is important to work with a fluid supplier that specialises in both cleaning fluids and vapour degreasing. They can recommend the fluids and the methods that will work best.
