Efficient Thermobonding Process Forming a Polyurethane Based Diagnostic Catheter with Liquid Crystal Polymer

Diagnostic and therapeutic catheters play an inevitable role in minimal invasive medical procedures. Unfortunately, standard catheters show a limited transducer density and high production efforts. We propose a novel catheter design and manufacturing method using a liquid crystal polymer (LCP)-based flexible printed circuit board (FPCB) and a thermoplastic polyurethane (TPU) elastomer tube. Both components are bond together with a low cost, additive free lamination process at a re-flow temperature of 250° C. The lamination process is improved with a laser welding seam and LCP-integrated microholes preventing delamination. Standardized Mechanical tests were conducted to characterize the bonding. A Peel strength of up to 8.5 N in the radial direction and a non plastic elongation in the axial direction of 10% provide evidence that the thermobonding process is suitable for the production of flexible and mechanically durable medical catheters featuring high electrode densities.