In PCB production, polishing refers to cleaning and conditioning the surface of the substrate before subsequent processes, such as copper plating, circuit pattern etching, or interlayer connections.
Materials used for polishing typically include polishing compounds along with automated polishing machines to achieve a smooth surface free of oil, dust, or scratches. Any of these contaminants can negatively affect electrical conductivity and the PCB’s lifespan.
Polishing before copper plating is crucial. A greasy or dirty surface prevents copper from adhering properly, which can cause delamination during heat processes. High-quality polishing ensures a uniform copper surface, increasing adhesion strength between metal layers.
In PCB production, even tiny surface irregularities can lead to short circuits or open circuits. Polishing helps remove impurities such as oxide residues, dust, and metal particles that could later cause defects.
Rough surfaces can prevent photoresist or circuit printing ink from spreading evenly, reducing pattern precision. Polishing ensures a clean, smooth surface for sharp and accurate circuit printing.
Properly polished surfaces make soldering easier and more reliable, reducing issues like poor adhesion or air bubbles, which directly affect the PCB’s quality and longevity.
Uses brushes and cleaning solutions to remove oxide layers and contaminants from the copper surface. Ideal for surface preparation before plating or pattern printing.
Uses mild acids or specific chemicals to dissolve oxides and grease on copper surfaces. Often combined with mechanical scrubbing for optimal results.
Partially etches the copper surface at the microscopic level, creating a slightly rough texture that improves adhesion between copper layers and the coating film.
After polishing, the surface must be rinsed immediately with purified water to remove copper particles and chemicals, preventing residue that can affect pattern printing.
These issues not only increase production costs but also compromise brand reliability and end-user safety.
Although polishing may seem like a simple surface preparation step, it is the foundation of PCB quality. Without a clean and smooth surface, all subsequent processes are more prone to defects.
Therefore, standard PCB manufacturers pay great attention to this step, using high-quality polishing equipment, suitable polishing compounds, and precise control of pressure, speed, and duration to ensure PCBs are durable, accurate, and ready for use in modern electronics.
