Y. Shen, D. A. L. Loch, E. Mann, TRUMPF Hüttinger GmbH + Co. KG, Freiburg im Breisgau, Germany
The growing demand for high-end printed circuit boards (PCBs) in telecommunications, automotive, and aerospace industries is driven by advanced packaging technologies and the increasing miniaturization of electronic components. This work highlights our innovative power supply solutions tailored for Cu layer plasma etching and deposition in advanced PCB manufacturing. Specifically, we focus on the applications of dual-frequency RF (13.56 and 2 MHz) for etching, and HIPIMS for Cu deposition. These technologies enable precise processing essential for achieving ultra-fine line-and-space geometries, a key requirement for advanced packaging in high-density PCBs.
For Cu dry etching, RF power at 13.56 MHz ensures high ionization efficiency, while 2 MHz bias RF enhances etching uniformity and depth control. Recent advancements, in collaboration with industry leaders, have shown significant improvements in ~50% increase in etch rate, uniformity improvement, energy delivery and impedance handling. This dual-frequency approach enables unparalleled process flexibility, crucial for manufacturing PCBs with line/space geometries down to 2 µm.
Additionally, HIPIMS with rectangular current waveform has emerged as a superior technology for Cu layer deposition in PCB manufacturing, which could outperform conventional HIPIMS by providing enhanced film adhesion, higher deposition rates, and superior film quality. Key advantages include integrated arc management, precise pulse control, and compatibility with diverse substrates, such as those used in flexible copper-clad laminates (FCCL) for wearable devices and 5G applications. Case studies demonstrate that HIPIMS technology achieves consistent results across large-scale production, doubling deposition rate while maintaining same quality.
In this work we present cutting-edge plasma-assisted manufacturing solutions for high-end PCBs, and related analysis of the technical advantages, in order to meet the critical challenges in miniaturization and high I/O density required by next-generation devices.