Smart pH Employment in Electronics Cleaning

Cleaning is a dynamic process. No one single facet can be studied on its own. Soil loading (flux, and other assembly contaminants), temperature, exposure time, mechanical energy, and the cleaning agent all react together within the wash process. These interactions affect the entire cleaning process, wash, rinse, and the environment. The pH of a cleaning agent affects the entire cleaning process.

The terms “acidic”, “alkaline” and “neutral” refer to positions on a scale of pH ranging from 1 to 14. A solution can have a pH below 1 and above 14. However, this range is most used. A pH of 7 is neutral, while numbers less than 7 are acidic and greater than 7 are alkaline or basic. A neutral pH of 7 is thought of as being desirable because the fluids of a human body are close to this value. Consequently, if skin meets a solution, either above or below 7, the skin may become irritated. A neutral pH does not indicate whether a liquid is safe to drink or not. If one was to ingest dish soap, the individual will likely become sick even though most mild dish soaps have a pH of 7-8.

Alkaline solutions are better at cutting through dirt, grease, proteins, oils, and other organic items. Acids are better for removing calcium, rust, and other minerals. Highly acidic products (below pH 3) are referred to as corrosive, and those that are highly alkaline (above pH 11) are considered caustic. Products with pH values between 6 and 9 are found to be within the pH neutral range. Products that measure at either end of the pH scale are not recommended for electronics assembly cleaning for multiple reasons. Solutions that have a pH at the extreme ends of the spectrum will react with metals. Depending on the solvents used, they may negatively interact with certain plastics, epoxies, and coatings.