Hot embossing of microfluidics in cyclic-olefin co-polymer using a wafer aligner-bonder

The fabrication of robust microfluidics can be tedious, often involving the use of numerous cleanroom resources and processes. We propose a process that is easy to apply yet capable of producing precision microfluidics in polymer with high yield and high fidelity at a wafer scale. The process is centered on the use of a wafer aligner-bonder implementing a one-step hot embossing process to transfer microfluidic designs from a Si master mold onto a thermoplastic deformable substrate. The approach has the additional benefit of transferring features directly to the substrate without the need for pre-annealing or other pre-processing. Additionally, the mold used to replicate the microfluidic design can be re-used numerous times. The most important process parameters, embossing temperature, embossing pressure, embossing time and demolding temperature, were optimised. We demonstrate the process by fabricating over 340 microfluidic chips per 4-inch diameter cyclic-olefin co-polymer substrate. The approach should scale to larger wafer diameters using a wafer aligner-bonder of larger diameter platens, suitable for volume manufacturing.