The etching process is a fundamental step in the production of printed circuit boards (PCBs). It involves removing unwanted copper from the board to create circuit patterns and pads. While the etching principle seems simple, achieving precise results, especially for fine lines, is quite challenging. Traditional horizontal etching methods often lead to uneven etching effects, known as the “pool effect,” which can compromise the quality of ultra-fine structures.
Challenges of Horizontal Etching:
Horizontal etching, while preferred for its automation and cost benefits, results in uneven etching effects due to the “pool effect.” This effect causes faster etching rates at the board’s edges compared to the center, leading to over-etching of edge lines and poor etching results at the center.
The Vacuum Etching Solution:
PILL e.K. has introduced a revolutionary vacuum etching technology that addresses the “pool effect” by improving the fluidity of the etchant in the upward-facing portion of the board. This vacuum etching method involves installing suction units between etching nozzles to remove used etching solution and return it to a closed circuit liquid tank.
Benefits of Vacuum Etching:
The first vacuum etching line was showcased at Productronica in November 2001 and has since been validated by circuit board manufacturers. Vacuum etching ensures uniform etching effects on both sides of the board, reducing the need for complex engineering controls. This streamlined process has been proven to achieve excellent results with minimal effort.
Conclusion:
Vacuum etching technology offers a simple yet effective solution to address the challenges of traditional horizontal etching methods. By eliminating the “pool effect,” this innovative process ensures precise and uniform etching for ultra-fine structures on PCBs.