Fraunhofer Institute for Applied Optics and Precision Engineering IOF
UV molding is a cost-effective method of producing micro-optics on wafer scale. Here, a liquid polymer resin is UV-cured between a substrate (e.g. glass or semiconductor wafer) and a transparent molding tool in a contact mask aligner.
The process has become established in fields in which the precision or stability of all-polymer optics is insufficient, e.g. in
- Collimation of laser or fiber arrays
- Diffractive elements
- Micro-optics directly on CMOS-Si wafers
- Wafer-level miniature cameras
or other complex/multi-layered micro-optical systems.
Using selective UV exposure, areas of the substrate surface can remain polymer-free for electrical contacts or assembly.
UV molding can also be used for the rapid generation of optical functional prototypes prior to mass production (e.g. with injection molding).
The use of correspondingly stable UV-curable polymer resins enables subsequent coating/scribe and breaking and other steps such as soldering or bonding.