High-Quality Conductive Bellows Coatings Using Conformal Ionized PVD To Replace Unreliable Electroplating Processes

High-quality and functionalized material surfaces are essential for next-generation particle accelerators supporting nuclear physics research, i.e. LCLS-II-HE, EIC, CEBAF. Traditionally coatings and surface functionalization are performed with wet chemistry/electroplating; however, process irreproducibility, contamination and ever decreasing supplier base as environmentally-unfriendly wet chemistry is phased out has led to repeated component failures, more risk, higher cost and delayed timelines. Both JLAB and FNAL recently faced this challenge coating high-conductivity copper onto flexible de-coupling bellows for the SLAC LCLS-II-HE cryomodule upgrade, as well replace a bellows waveguide assembly on CEBAF. Phase I demonstrated that the IMPULSE® next-generation HiPIMS technology could conformally coat particulate-free, adherent, thick-film conductive films, specifically for use in the bellows, spool and flange sections of particle accelerators for LCLS-II and beyond—to replace wet chemical electroplating. The Positive Kick™ feature enables adjustable ion energy control to surfaces for conformal deposition of dense, ultra-smooth thick films onto 3D shapes with control of purity, particles, adhesion, stress, morphology and crystallinity. The Super Kick™ enables substrate etching and cleaning to remove microcracks, relieve surface stress and achieve excellent adhesion. Phase II will demonstrate coatings on LCLS-II-HE and CEBAF bellows and scale for manufacturing. The IMPULSE® + Positive / Super Kick™ technology provides a means to achieve superior coatings for research physics and industrial particle accelerator applications. It also reduces environmental impact by eliminating large chemical waste streams associated with tradition electrochemical processing, such as copper plating. Benefits include superior coatings on older accelerator beam pipe surfaces to lower resistance, smoothen for higher gradients and decreased electron emission, and improved thermal conductivity. The technology also has application for advanced high-density microelectronic packaging to replace wet chemical copper plating to enable high-density redistribution layers and vias. The technique will also support industrial accelerators in order to provide low cost, reliability and long-term stable operation. The SBIR program will also support emerging small businesses and job creation in the Midwest.