LPKF ProtoLaser LDI for high-precision resist structuring

LPKF has developed a process for the structuring of microcomponents. Maskless UV laser direct imaging (LDI) of photosensitive polymers (photoresists) offers numerous advantages over classic mask projection techniques.

In the electron beam method, the structures are written directly onto a resist. The electron beam has resolutions of between 20 and 50 nm. However, special resists, conductive substrates, a high vacuum and a large amount of time are required for this process. With LDI, a scanner-guided laser beam writes structures directly, rapidly and precisely onto the photoresist without using a mask. This results in smooth side wall edges.

The LPKF ProtoLaser LDI can be used for the production of microfluidic devices as well as MEMS, BioMEMS, integrated optics and photonic experiments with microscale structures. In terms of precision, LDI is claimed to surpass all comparable systems for mask projection. The technique even enables structuring of elements with web widths of less than 1 µm.

Other features include: substrate exposure with a focused 375 nm TEM00 UV laser beam, which can also be used for standard UV resists; software-controllable laser focus (1–3 μm) for changing precision requirements; and an integrated camera for fine positioning of substrate and automated self-calibration as well as stitching mechanisms for real-time manufacturing of large samples.