Feature: Avionics


Newer formulations of vapour degreasing fluids offer excellent performance whilst addressing environmental concerns


custom formulas to remove a specific soil from a specific substrate, maximising cleaning effectiveness.


Fluid characteristics Tere are several important characteristics to consider when choosing the right vapour degreasing cleaning fluid. Non- flammable cleaning fluids are highly recommended, as they ensure safer handling and storage and don’t need fire or explosion-proof equipment. Most vapour degreasers are designed to work seamlessly with non-flammable cleaning fluids. Opting for low-boiling-point cleaning


fluids is advantageous in terms of energy efficiency and safety. Cleaning fluids with a boiling point below 100°C can still clean PCBs effectively whilst enabling the vapour degreaser to be more energy efficient. Moreover, using lower boiling temperatures allows for the safe cleaning of delicate PCB components without risking damage. Te cleaning fluid’s surface tension and


viscosity are other critical characteristics. Low surface tension and viscosity ensure the entire PCB surface is entirely wetted and the fluid can penetrate all tight spaces, including under low-mounted components. High-density cleaning fluids are


particularly beneficial when dealing with particulates like dust, dirt or cloth fibres that don’t dissolve. High-density fluids are typically 20-30% heavier than water and 50% heavier than alcohol and can easily move particulates off the PCB surface. Te solvency or strength of the cleaning


fluid is also a crucial consideration. Cleaning fluid strengths are oſten indicated by a Kb value, which ranges from mild to strong. Kb (Kari-Butanol) refers to a standardised ASTM test that measures the relative strength of a non-aqueous cleaning


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fluid. It is important to choose a cleaning fluid with a high enough Kb value and solubility parameter, to effectively dissolve and remove contaminants without causing damage to the PCB substrate. Maintenance-free cleaning fluids


are also desirable. Many modern-day vapour degreasing fluids remain stable,


Vapour degreasing has emerged as a highly efficient cleaning method for avionic PCBs


eliminating the need for acid acceptance testing, lab analysis or other maintenance. Tis ensures a hassle-free cleaning process and reduces the time and effort required for maintenance tasks. Lastly, environmental stability should also


be a key consideration. Newer formulations of vapour degreasing fluids offer excellent performance whilst addressing environmental concerns. Tese fluids have low Global Warming Potential, reducing the impact on greenhouse gas emissions, and low Ozone Depleting Potential to comply with strict regional air quality regulations. Choosing environmentally-sustainable cleaning fluids contributes to maintaining a cleaner and safer environment.


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