The development trend of the electronic information industry requires more and more PCBA assembly processes, and the reliability and quality of electronic machine products are mainly determined by the reliability and quality level of PCBA. electronic pcb assembly
Residues on PCBA mainly come from the assembly process, especially the welding process. Such as the use of flux residues, flux and solder reaction by-products, adhesives, lubricants, and other residues. Some other sources of potential harm are relatively small, such as components and PCB itself production and transportation of pollutants, sweat stains, and so on. electronic pcb assembly
These residues can generally be divided into three main categories.
1. non-polar residues, mainly including rosin, resin, glue, lubricants, and so on. These residues can only be cleaned with non-polar solvents can be better removed.
2. polar residues, also known as ionic residues, mainly include flux in the active substances, such as halogen ions, a variety of reactions generated by the salts, these residues need to be better in addition to the exhaustion of polar solvents must be used, such as water, methanol, etc.
3. weak polar residues, including mainly from the solder in the organic acids and bases, the removal of these substances to obtain good results, must use complex solvents.
PCBA on the residue on its impact?
1. Electrical performance impact: some components in the flux may penetrate the PCB board in the small holes, resulting in a short circuit or open circuit. This will directly affect the electrical performance of the PCBA, which may lead to the product not working properly or intermittent failure.
2. Reduced Reliability: Flux residue may attract dust and contaminants, forming conductive paths, which can reduce the long-term reliability of the PCBA. In addition, residual flux may be chemically altered over time, resulting in corrosion, further affecting the reliability of the PCB.
3. Increased thermal resistance: flux residue may increase the thermal resistance of the PCB board, affecting the heat dissipation of electronic components. In high-temperature environments, this may lead to increased component temperatures, affecting their stability and life.
4. Appearance Impact: Flux residue may lead to the poor appearance of the PCBA, affecting the quality of the product’s packaging and appearance. In some cases, this may lead to a decrease in the competitiveness of the product in the market.
5. Safety issues: If flux residues contain hazardous substances, such as heavy metals or harmful volatile organic compounds (VOCs), they may cause long-term harm to human health and the environment.
6. Signal Interference: In high-speed signal transmission applications, flux residues may cause signal interference and electromagnetic compatibility (EMC) problems, affecting product performance and stability.
Therefore, for the flux residue problem in the PCBA manufacturing process, it is necessary to control and reduce the residue through an effective cleaning process to ensure the quality and reliability of the product. electronic pcb assembly