micromolding

Micromolding refers to the fabrication of plastic parts with dimensions in the micrometer to millimeter range through molding processes designed for microscopic features. The field includes microinjection molding and related techniques aimed at high-volume, high-precision replication of tiny components.

Microinjection molding uses specialized machines with tiny shot sizes, a high-precision screw, and accurate metering to deposit small amounts of molten polymer into micro molds. Other methods include hot embossing, micro-stamping, and LIGA-based molding, which combine lithography and molding for very small features.

Molds are produced with ultra-precision machining and micro-EDM; materials include high-strength steel and carbide. Common plastics include POM, PC, PMMA, PEEK, and UV-curable resins for rapid prototypes; elastomeric polymers are used for soft microstructures.

Replication fidelity depends on tool quality, shrinkage control, gate and vent design, and process parameters such as packing pressure and melt temperature. Defects include flash, short shots, demolding damage, and micro-scale edge imperfections. Metrology uses optical microscopy and micro-CT.

Applications include medical devices, microfluidic components, electronics connectors, optical elements, and micro-mechanical components. Challenges in micromolding include high equipment cost, limited material choices for some microfeatures, longer setup times for tooling, and the need for precise process control to maintain tight tolerances at small scales.