• • • SAFETY IN ENGINEERING • • • Maintain a healthy and

productive working environment Employers have a statutory obligation to maintain a healthy working environment for their people, but aside from the moral imperative there are also solid productivity reasons for maintaining a workplace free from fume and dust. That’s why extraction systems, such as those developed by BOFA International, are seen as essential components in a growing range of process-based industries, including electronics and notably in PCB manufacture

require the use of an alcohol-based solvent such Iso Propyl Alcohol (IPA) and a small amount of organic acid, fume from which needs to be controlled, extracted and filtered.


oshua Evans, applications engineer at BOFA International, a global leader in portable fume extraction says, “Potentially harmful airborne contaminants can result from numerous industrial processes, including automated soldering.” “Health risks are associated with thermal plastic processes and solvents, which can give off volatile organic compounds (VOCs). PVC is worth a special mention in this context since it releases hydrogen chloride/hydrochloric acid and small amounts of phosgene when lasered or thermally processed, both of which are highly toxic.”

In the UK, strict rules are in place governing exposure levels to potentially harmful airborne contaminants. These are mandated through the COSHH (Control of Substances Hazardous to Health) regulations and expressed as workplace exposure limits (WELs) presented as time weighted averages for either 15 minutes or 8 hours, in both ppm (parts per million) or mg/m3 (milligrams per metre cubed). Employers who contravene these regulations risk significant penalties. BOFA system design is matched to each

industrial application and takes account of the quantity and size of particulate emitted and its chemical composition, including toxicity of each element of the process and any resultant chemical interaction.

This will inform the design of the system architecture, the filtration media used, the integration of sensors (for high temperature applications for example) and the most appropriate monitoring and control mechanisms. Automated soldering processes have a significant and positive impact on productivity in the electronics industry, but to optimise these gains, businesses also need to invest in fume extraction


solutions that offer flexibility as well as ensuring safe working environments.

Whereas the default position for electronics companies was once to hook up any new or changed process to a vent-to-air or centralised exhaust system, now portable extraction systems, such as those designed by BOFA, are increasingly gaining traction to support the agile working practices driving improved productivity. What automation doesn’t do, of course, is to de- risk industrial processes. While it can reduce manual contact – in soldering for example - automated processes often present different hazards that need to be controlled. Take wave soldering for example. Here, the ‘through-hole’ components are placed on the printed circuit board and passed over a continuous wave of molten solder. Areas not to be soldered are covered with a protective ‘mask’. While this process doesn’t involve the resin/colophony present in hand soldering (with its inherent risks of occupational asthma), it can

Before soldering, the boards are ‘spray fluxed’. This can be a general spray, which generates an airborne dispersion of the flux, or a targeted jet from a robotic nozzle. Either way, airborne contaminants are created that can irritate eyes and lungs, while any IPA vapour concentration may cause drowsiness and dizziness, throat irritation and a feeling of tightness in the chest. With reflow soldering, solder paste is applied to the PCB and components are then ‘picked and placed’. The board moves through various heating, stabilising and cooling zones, during which the solder metal ‘reflows’ or melts and solidifies around the component connection. During this process, the solvent which makes the paste liquify will evaporate and will need to be extracted/filtered. The fume from this process will include rosin content, with the associated health risks. A solder flux may also be used, which is likely to possess a significant concentration of ammonium chloride. As with wave soldering, operating temperatures need to be taken into account to ensure the effective capture and filtration of any potentially harmful emissions. Joshua explains: “BOFA’s portable fume extraction solutions combat all these risks, through multi-stage filtration technology that includes specialist activated carbon filters designed to capture specific chemical emissions. “This ensures a particulate filter efficiency of

near 100 per cent (99.997 per cent) is achieved, working towards compliant health protection while helping deliver the productivity gains that come from mobile technology and fume and dust free process lines.” BOFA technology for automated soldering processes includes the V 2000 iQ, a high airflow fume extraction system for reflow ovens and wave solder machines. Large filter capacity and carbon filters ensure long filter life and optimal extraction even when lead free solder is used. In addition, BOFA’s iQ operating platform has introduced new levels of control, including independent filter status monitoring to improve extraction efficiency, reduce the risk of downtime and lower the overall cost of system ownership.


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