In the past, people's understanding of cleaning was not sufficient, mainly because the PCBA density of electronic products was not high, and it was believed that the residual flux was non-conductive and benign, which would not affect the electrical performance.
Nowadays, electronic assembly design tends to be miniaturized, with smaller devices and spacing. Pins and pads are getting closer and the gaps are getting smaller, and pollutants may get stuck in the gaps. This means that smaller particles may cause potential defects such as short circuits if left between two pads.
In the past two years, the demand for cleaning in the electronic assembly industry has become increasingly high, not only for product requirements, but also for environmental protection and human health.
Nowadays, cleaning processes are used in the production and manufacturing of many PCBAs. Different levels of products require different cleaning agents, required equipment, and different processes. Most equipment suppliers have launched cleaning machine equipment and their cleaning solutions, first detecting and analyzing residual materials after welding in manufacturing factories, and then providing targeted system cleaning solutions. There are fully automated online cleaning machines, semi-automatic offline cleaning machines, manual cleaning machines, etc., suitable for all water-based (cleaning with ionized water), semi water-based (cleaning with chemical aqueous solutions, such as saponification solution), and all chemical solvents for cleaning. Many companies tend to use water-based cleaning agents and develop towards environmental friendliness.
PCBA cleaning precautions (1) Printed circuit board assembly parts should be cleaned as soon as possible after welding (because solder residue will gradually harden over time and form corrosive substances such as metal halides), thoroughly removing residual solder, solder, and other pollutants from the printed circuit board. (2) During cleaning, it is important to prevent harmful cleaning agents from entering the partially sealed components to prevent damage or potential damage to the components. (3) After cleaning the printed circuit board components, they should be placed in an oven at 40-50 ℃ and dried for 20-30 minutes. Before the cleaning parts are dry, they should not be touched with bare hands. (4) Cleaning should not affect components, labeling, solder joints, and printed circuit boards.
