During the SMT assembly process, residues of solder paste and flux are often left behind on PCBA boards. These residues contain various components, including organic acids and decomposable ions. Organic acids are highly corrosive, and residual ions on solder pads can cause short circuits. Additionally, these residues make the PCBA boards dirty and fail to meet customer requirements for cleanliness. Therefore, cleaning PCBA boards is inevitable. However, PCBA boards cannot be cleaned casually; strict requirements and precautions must be followed when using a PCBA cleaning machine. Here are some considerations to keep in mind during the PCBA board cleaning process:
- After assembly, PCBA boards should be cleaned as soon as possible to thoroughly remove residual solder flux, solder, and other contaminants. This is because residues of flux harden over time and form corrosive substances like metal halides.
- During cleaning, precautions should be taken to prevent harmful cleaning agents from penetrating into unsealed components to avoid damage or potential damage.
- After cleaning PCBA assemblies, they should be placed in a 40-50°C oven and dried for 20-30 minutes. Components should not be touched with bare hands until they are completely dry.
- Cleaning should not adversely affect components, markings, solder joints, or the PCB itself.
PCBA board cleaning is primarily aimed at dissolving and removing solder residues. The goal is to ensure good surface resistance and prevent leakage, thereby extending the product’s lifespan. As electronic products continue to shrink in size, the demand for high performance and reliability is stronger than ever. Thoroughly cleaning PCBA boards is crucial for product longevity, reliability, environmental protection, and human health. Implementing a cleaning solution involves coordinating the use of soldering materials such as flux, solder paste, and solder wire. Matching solvent-based solvents, inorganic solvents, mixed solvents, water-based washing, or no-clean methods is essential for effectively removing residues and meeting customer requirements for cleanliness while ensuring product quality.
