Optically dense resists play an increasingly important role in industry. So-called black resists are required in optical industry, in automotive industry (for headlights) and in the manufacture of rotary encoders. While in optical and automotive industry mainly the suppression of light reflections is concerned, such resists are also directly applied e.g. in structuring processes for the production of rotary encoders. The black resist SX AR-N 8355/7 was already successfully used for the structuring of code disks by PWB encoders GmbH, Eisenach. Figure 1 demonstrates the excellent contrast between black resist areas and the freely developed code disc.
Fig.1 Segment of a code disc, structured with black resist SX AR-N 8355/7
Meanwhile also resists with other colours or fluorescent dyes are available. Allresist has now submitted a ZIM research project which is aimed at the development of further coloured resists. Particular emphasis is placed on the long-term stability of the dyes (>10 years). Due to the use of defined nanoparticles, this goal appears indeed achievable. The first industrial applications of black resists were reason enough for us to choose this product as resist of the month.