Session 6: RF & Security

Copper Micro-Wires for RF Applications
Wednesday, February 14, 2018
8:45 AM - 9:05 AM

As the connectivity of the world increases, so does the proliferation and integration of antennas. The fabrication of flexible, optically transparent antennas using transparent conductive film (TCF) technology would expand antenna placement options to windows, displays, lighting, and other glass surfaces. While there has been some work to use the available TCF technologies to fabricate transparent antennas, demonstrations to date have had limited transparency or antenna efficiency – or (more typically) both. Kodak has developed an additive, roll-to-roll (R2R) manufacturing process to produce transparent RF devices, such as antennas and EMI shields, on flexible substrates. Kodak’s copper micro-wire technology delivers low sheet resistance in combination with high transparency, neutral color, and low reflectance. The manufacturing process includes in-line passivation to protect the copper metal from corrosion plus printing capability for adding nonconductive features to further enhance the ability to hide antennas on surfaces where high optical performance is required. While the transparency of TCF-based antennas will enable their integration with glass surfaces, the electrical attributes of the antennas must deliver adequate RF performance. Benchmark performance is that of current thin-film antennas, which are typically fabricated from bulk copper, in both printed circuit boards (FR4) and flexible circuits (copper on Kapton®). In this talk, we will focus on the technical requirements for transparent conductive materials for RF applications, with a focus on how materials and process influence performance. In addition to TCF materials properties and fabrication discussion, data will be provided on RF devices produced using Kodak’s copper micro-wires and manufacturing process.