PCB is widely used in China. There are some contaminants including flux and adhesive in PCB manufacture. There are other pollutants produced in the manufacturing process, such as dust and debris. If the surface of PCB is not clean, resistance and leakage will lead to the failure of PCB. This will affect the service life of the product. Therefore, the cleaning of the PCB board is a very important link in the manufacturing process.
There are currently four ways to clean a PCB:
1. Semi aqueous cleaning technology
Semi-water cleaning mainly used organic solvents and deionized water. And then add a certain amount of active agents, additives composed of cleaning agents. This kind of cleaning is between solvent cleaning and water cleaning. These cleaning agents are organic solvents, flammable solvents, high flash points, and low toxicity. It is safe to use, but it must be rinsed with water and then dried.
2. Water cleaning technology
Water cleaning technology is the development direction of cleaning technology in the future. It is necessary to set up a clean water source and discharge water treatment workshop. It uses water as the cleaning medium and adds surfactants, auxiliaries, corrosion inhibitors, chelating agents, and so on. These can form a series of water-based cleaning agents. This will remove water solvents and non-polar contaminants.
3, free cleaning technology
During the welding process, the free cleaning flux is used to remove the solder paste. After welding, it goes to the next process without cleaning. Free cleaning technology is the most used replacement technology currently. In particular, the free cleaning method is generally used to replace ODS in mobile communication products.
4, solvent cleaning technology
Solvent cleaning is mainly to remove contaminants using solvent dissolution. Because of its fast, solubilization is strong, so it is a simple device.
The above four kinds of cleaning technology can achieve a certain cleaning effect. But how do quickly and more effective cleaning PCB? The application of an ultrasonic cleaning machine can solve this. It uses the ultrasonic high-frequency conversion of kinetic energy to re-act on the liquid medium. It is resulting in cavitation. The formation of numerous micro-bubbles burst, and then impact the surface of objects. So that the dirt on the surface will come off. Thereby it can achieve a cleaning effect. As a result of the action of the liquid, so long as the liquid can reach the surface of the object, it can be cleaned in place. And it leaves no dead angle. And this can act on each surface of many objects at the same time. The efficiency is extremely high, the speed is very fast. Generally, it can be cleaned in 15 minutes. Another advantage of using the ultrasonic cleaning method is that it can effectively deoxidize, and enhance the welding ability of pad and component pins. And it can reduce electromagnetic interference.
