Cleaning agent in PCB manufacturing

The cleaning agent is mainly used for post-weld cleaning of assembled boards, to remove flux residues after reflow, wave soldering and manual soldering, as well as contaminants caused during the assembly process.

1. Requirements for cleaning agents

A. It has strong dissolving ability for pollutants, can effectively dissolve and remove polluting impurities, leaving no residue and scars.

B. It does not corrode equipment and components, and easy to operate.

C. Non-toxic or low-toxic.

D. Non-combustible, non-explosive, stable physical and chemical properties.

E. Low price, low consumption and easy recycling.

F. Low surface tension is beneficial to penetrate the narrow gap between the component and the substrate and improve the cleaning efficiency.

G. It is harmless to the environment. It is best to use non-ODS solvents.

2. Classification of cleaning agents

Cleaning agents are classified into organic solvent cleaning agents, water cleaning agents, and semi-aqueous cleaning agents.

3. Non-ODs organic solvent cleaning agents mainly have the following 4 kinds

A. Fluorine-based solvents such as HCFC, HFC, HFE.

B. Hydrocarbon solvents, like hydrocarbons such as methyl chloride

C. Alcohol solvents such as ethanol, isopropanol.

E. Water-based cleaning agent. In addition, there are ketones, lipids, ether solvents, organosiloxanes, and a mixture of a plurality of substances.

4. Performance requirements of organic solvent cleaners

A. The cleaning agent is required to have a small surface tension and good wettability, and can fully expand on the surface of the workpiece to be cleaned.

B. Good solubility. The molecular structure of the solvent and contaminants should be similar, so that they are easily dissolved in each other. The solubility of the solvent is generally increased by selecting appropriate equipment, agitation methods, or increasing the cleaning time.

C. The solvent chosen should not corrode the printed board and components during cleaning.

D. Solvent cleaners are usually made by mixing polar and non-polar substances and are commonly used to adjust and balance solubility.

E. The nourishing agent should not leave harmful residues after the final rinse.

F. Good stability, long service life, stability depends on the resistance to chemical decomposition and thermal decomposition.

G. The solvent cleaning agent is required to be safe. Users must consider the effects of anti-fire prevention and anti-explosion on human health.

H. Low cost