3-D micromesh

The fabrication methods of the 3-D micromesh Ni structures were developed by modifying the multi-angle exposure of UV photpresist [ 11-13 ]. An inverse-micromesh frame was fabricated by multiple inclined backside exposures, and Ni was electroplated using the inverse-micromesh frame as a mold (Fig. 5.12). In this process, a... 

Cr patterns are formed on the backside of the glass snbstrate in addition to surface Cr/Au patterns. Cr patterning on both sides enables to define the exposure areas. For finer patterns, exposure areas cannot be defined perfectly dne to the inflnence of UV diffraction at the edge of backside Cr patterns even if Cr shadow layers are formed on both sides of a glass substrate. For this reason the negative resist (CA3000) was formed to avoid formation of Ni walls between metal electrodes. Two additional techniqnes enabled the realization of the 3-D micromesh metal structnres formed on the planar electrodes on the glass surface. 

By adding the backside Cr patterning and the protecting resist to the conventional techniques, comb-shaped 3-D micromesh Ni structures were fabricated as shown in Fig. 5.13. The gap between the micromeshes is 30 pm, the height of the mesh structure is 20 pm, and the diameter of the inclined micropillar is about 3 pm. The inverse-micromesh mold was filled with Ni using a ring-shaped Au as a seed layer for electroplating. Adequate metal is required on the Ni surface for actual use. 

Sato H, Kakinuma T, Go JS, Shoji S (2004) In-channel 3-D micromesh structures using maskless multi-angle exposure and their microfilter apphcation. Sens Actuators A 111 87-92... 

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