Polydimethylsiloxane (PDMS) based optical interconnect with copper-clad FR4 substrates

Abstract PDMS based optical interconnect has been developed based on a combination of PDMS waveguide fabrication technique and a process for efficient interfacial bonding between PDMS optical layers and standard copper-clad FR4 printed circuit boards (PCB) materials, in order to avoid outgas influences from epoxy based FR4 on waveguide loss of optical interconnect at 850 nm. The optimal bonding conditions between PDMS and copper-clad FR4 have been identified by applying a specifically developed surface adhesion promoter and surface treatment on copper-clad FR4. The optical and mechanical properties of the PDMS waveguide layer remained unchanged by the addition of the SAP and surface treatment on copper-clad FR4 as well as the environmental stability of realized optical interconnect.