Smart electronics need smarter fume extraction

The processes involved in the manufacture of PCBs are not without risk for the skilled people working within this sector, particularly those technicians exposed to rosin-based solder flux fume (colophony).

Colophony is a significant cause of occupational asthma and inhalation is known to cause irritation of the nose, throat and respiratory organs. This is why regulatory bodies set exposure limits or standards for rosin-based solder fume. In the UK, for example, the limit is defined as ‘as low as reasonably practicable below an 8-hour time-weighted average (TWA) of 0.05 mg/m3, and a 15-minute TWA of 0.15 mg/m3’.

Investing in appropriate local exhaust ventilation will remove fume from the workplace and help towards ensuring that people go home healthy. So, BOFA International, a global leader in portable fume extraction technology, is urging businesses to check that their extraction systems remain fit for purpose during this period of rapid growth.

“According to a recent analysis, the global PCB market is predicted to reach around USD80 billion by 2024 – this presents significant opportunities for companies but can also put pressure on production capacity,” says David Thompson, Business Development Manager at BOFA.

“So, when businesses are planning for growth, we would advise them to ensure that their existing fume extraction systems are maintained in optimal condition and that any new investment in manufacturing includes the latest technology to remove airborne contaminants. In this way, extraction technology will help workplace environments stay safe for employees while contributing to achieving productivity goals.”

While reducing manual contact, automated processes often present different hazards that need to be controlled and while the health risks associated with manual and automated soldering are widely understood, there are other processes in PCB manufacture and assembly that can also be a cause of concern.

For example, the batch marking by laser of PCB boards is key in traceability for the electronics sector, but the emissions resulting from lasering can include solid particles, liquid droplets or vapours/gases, and can be particularly hazardous to respiratory function, depending on the substrate and laser parameters.

Another example is conformal coating, which protects PCBs from ingress of dust and moisture. This process is likely to involve organic chemicals (e.g. cyclohexane, xylene, etc.), which will give off hazardous fume and mist, but which can be properly controlled by BOFA filtration technology. 

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 mentioned. 

Said David Thompson: “BOFA solutions combat all these risks through multi-stage filtration technology that includes specialist activated carbon filters designed to capture specific chemical emissions. 

“HEPA filters ensure a particulate filter efficiency of near 100% (99.997%) is achieved, contributing to compliant health protection while helping deliver the productivity gains that come from fume and dust free process lines.”

Popular BOFA technology for automated soldering processes includes the V1000 iQ, V1500 iQ and V 2000 iQ, high airflow fume extraction solutions for reflow ovens, wave solder machines and selective soldering systems. Large filter capacity and vast carbon filters ensure long filter life and optimal extraction even when lead free solder is used. It also offers adjustable and regulated airflow control to ensure consistently correct extraction rates as required by the process.