Method for manufacturing e.g. microfilter unit, that is utilized for filtering e.g. medium in food product application, involves separating filter layers by etching processes such as wet-chemical or dry-chemical etching processes

摘要

The method involves providing a substrate (10) i.e. silicon wafer, and providing a functional area with a function layer that is formed as filter layers with multiple pores or holes, where the filter layers are stacked one above the other and designed as microfilter layers or nano-filter layers. The filter layers of the substrate are separated by multiple etching processes such as wet-chemical etching processes or drying-chemical etching processes. A sacrificial layer (12) is provided between the substrate and the function layer. The substrate, the sacrificial layer and/or the function layer are made of ceramic, glass, metal, metal alloy or polymer. An independent claim is also included for a filter unit comprising two filter layers.