Understanding Copper Particles on PCB Board Surfaces

When dealing with PCB boards, the presence of copper particles on the surface can be a common issue that arises during various processes such as copper sinking, pattern transfer, or copper electroplating. In a recent visit to a large state-owned factory, it was observed that copper particles on the board surface were mainly attributed to the copper sinking process.

Causes of Copper Particles

• Issues during the copper immersion treatment, such as roughness due to high water hardness or excessive drilling dust
• Poor filtration leading to roughness on the board surface
• Problems with microetching agents like hydrogen peroxide or sulfuric acid
• Contamination or improper maintenance of the activation solution

Preventing Copper Particle Formation

Proper maintenance of process parameters, filtration, and tank cleanliness is crucial to prevent the formation of copper particles. Regular monitoring of bath parameters, material quality, and production operations can help ensure a smooth electroplating process without issues like copper powder formation in the bath.

Key Recommendations:

• Use high-quality microetching agents to avoid surface roughness
• Maintain proper activation solution to prevent impurities on the plate surface
• Keep copper sinking tanks clean and adjust process parameters as needed
• Clean anode bags regularly with suitable cleaning agents

By addressing these factors and implementing best practices in PCB manufacturing, the occurrence of copper particles on board surfaces can be minimized, ensuring high-quality and reliable electronic components.