The PCBA cleaning machine has the following requirements for cleaning solution:

1、In terms of chemical properties

PH value

The pH value of the cleaning solution needs to be maintained within a suitable range.If the pH value is too high(strongly alkaline),it may corrode the metal components on the PCBA,such as copper foil lines and tin in solder joints.For example,when the pH value of the cleaning solution exceeds 10,it may accelerate the oxidation and corrosion of copper.And if the pH value is too low(strongly acidic),it can also cause damage to the circuit board substrate and components.For circuit board substrates containing glass fibers,excessively acidic cleaning solutions may corrode the glass fibers and reduce the mechanical strength of the circuit board.The ideal pH value for cleaning solution is generally in the neutral or weakly alkaline range,such as 7-9,which can effectively remove pollutants while reducing damage to PCBA.

corrosive

The cleaning solution should have low corrosiveness.In addition to the influence of acidity and alkalinity,the chemical components in the cleaning solution themselves may also be corrosive.For example,some cleaning solutions containing halogen elements(such as chlorine and bromine)may undergo chemical reactions with metals on PCBA under specific conditions,producing corrosion products.Therefore,the cleaning solution should avoid containing highly corrosive components,especially for high-precision and high-value PCBA.Non corrosive or extremely low corrosive cleaning solutions should be used to ensure the long-term reliability of PCBA.

2、In terms of physical properties

Boiling point and flash point

The boiling point and flash point of cleaning solution are important physical parameters.A cleaning solution with a suitable boiling point helps with heating operations during the cleaning process.If the boiling point is too low,it is easy to evaporate during the cleaning process,resulting in changes in the concentration of the cleaning solution and unstable cleaning effect.If the boiling point is too high,a higher heating temperature may be required,increasing energy consumption and equipment costs.Flash point is an important indicator of cleaning solution,and cleaning solutions with lower flash points are prone to combustion when exposed to open flames or high temperatures,posing a hidden danger.Therefore,the flash point of the cleaning solution should be high to ensure the working environment of the cleaning machine.

surface tension

Lower surface tension facilitates better penetration of cleaning solution into the tiny gaps of PCBA and between components.When the surface tension is low,the cleaning solution can more easily enter tightly arranged pins,chip bottoms,and other areas,effectively removing pollutants.For example,some surfactants can reduce the surface tension of the cleaning solution,allowing it to better perform its cleaning function.

3、In terms of environmental performance

Volatile Organic Compounds(VOCs)Content

In order to meet environmental requirements,cleaning solutions should minimize the content of VOCs as much as possible.High levels of VOCs can evaporate into the air during use,causing air pollution and potentially endangering the health of operators.More and more regulations are restricting the VOCs emissions of cleaning solutions,so choosing cleaning solutions with low or no VOCs is a trend.

Biodegradability

Good biodegradability is also an important environmental indicator of cleaning solutions.After use,if the cleaning solution can be quickly decomposed by microorganisms in the natural environment,it can reduce long-term pollution to the environment.This is of great significance for sustainable development and reducing environmental pressure.