Progressive microforming is an attractive option for manufacturing high aspect-ratio micro-parts out of sheet metal. It is a highly economical alternative to both MEMS processing and micro-machining due to the ability to produce near-net shape parts through parallel forming processes. Current limitations in the field include precise alignment of microforming tools and an understanding of forces encountered when scaling down traditional forming processes. A five stage micro-progressive aluminum die set consisting of four shearing stages and one bending stage was fabricated by micro-machining. The die set was designed to produce right angle micro-brackets from 25 um thick annealed copper foil, with a measured average grain size of 47 um. Die clearances were set at 3 um along shearing edges and 38 um along the bending edge, corresponding to 12% and 152% material thickness, respectively. The produced micro-brackets are intended to be used as electrical connectors and consist of a nominally 280 um by 260 um tab extending vertically from a 780 um by 260 um base. In order to implement and investigate the progressive microforming process, a novel micro-press system was constructed which allows for precision alignment of the die set and workpiece. Using a prepared workpiece, forces at the first stage of the die set were measured and compared to analytical predictions based on models from the literature.

This content is only available via PDF.
You do not currently have access to this content.