The Slot-Die Coating Process

November 19, 2012 Greg Rosenberg

In the rapidly-growing medical device industry, thin film providers are playing both lead and support roles, driving new device design with conductive, wear-resistant and biocompatible coatings and delivering innovative technologies, processes and quality controls for device manufacturers.

While numerous coating techniques are employed in supporting device manufacturers, the slot-die coating process is particularly suited for this work. Unlike traditional roll-to-roll coating, slot-die coating is a closed-loop process where coating fluids are continually pumped and precisely metered. With no excess fluid to recirculate, slot-die systems significantly reduce the risk of contamination.

Slot-die systems also yield coatings of unmatched consistency and uniformity. This is critical in microthermoforming, where thin films are heated and molded to microdevices. When properties such as conductivity or biocompatibility are essential, films that lack uniform coating dispersion can compromise the integrity of the microdevice.

Because line speed and coating feed rates are scalable, slot-die systems provide production efficiencies without sacrificing coating quality. With coating thicknesses down to 0.1 microns, slot-die operations can be scaled for trial and batch runs of any size with remarkable consistency. This precision is crucial in the production of many device-critical components such as biopotential electrodes and chemical and temperature sensors.