Improved in dry routing performance with optimized diamond-like carbon films

• DLC films deposited on microrouter under a mixture of acetylene/argon plasma in ECR system.
• Router bit performance was evaluated by surface roughness of trench sidewall and precision width tolerance.
• Routing efficiency is relevant to the substrate bias voltage.
• It is verified for improving the tooled-life by optimizing DLC coated microrouter in PCB machining.

The efficiency of cutting tools was increased by deposition diamond-like carbon (DLC) films on microrouter bits to improve the chip flow and reduce cutting force. DLC films deposited under a mixture of acetylene/argon plasma in a large area and three dimensional deposition electron cyclotron resonance (ECR) system. Router bit performance in dry routing of FR-4 type printed circuit board was evaluated by inspecting the surface roughness of trench sidewalls and the routing precision width tolerance. By optimizing deposition conditions, the DLC lubricant-coated microrouter bits achieve a better enhancement in performance. Surface analysis with scanning electron microscopy reveals that DLC coated microrouters exhibit lower friction and enhance the anti-adhering properties of the microrouter, resulting in significant improvements in routing quality. The microstructure and chemical configuration are investigated by Raman spectroscopy and X-ray photoelectron spectroscopy, respectively. The routing efficiency shows a high dependence on the microstructure of DLC coating, which varies with deposition conditions, in particular with substrate bias voltage.