ABSTRACT
LIGA is the German acronym for X-ray lithography (X-ray lithographie), electrodeposition (galvanofor-mung), and molding (abformtechnik). The process involves a thick layer of X-ray resist (from microns to centimeters), high-energy X-ray radiation exposure, and development to arrive at a three-dimensional resist structure. Subsequent metal deposition fills the resist mold with a metal, and after resist removal, a freestanding metal structure results [IMM, 1995]. The metal shape may be a final product or serve as a mold insert for precision plastic molding. Molded plastic parts may in turn be final products or lost molds (see Figure 4.1). The plastic mold retains the same shape, size, and form as the original resist structure but is produced quickly and inexpensively as part of an infinite loop. The plastic lost mold may generate metal parts in a second electroforming process or generate ceramic parts in a slip casting process. (a) Basic LIGA process steps X-ray deep-etch lithography and first electroforming. (b) Plastic molding and second electroforming/slip casting. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429125461/39a0a5e2-53cb-49e9-916a-d225a0c9aa1b/content/fig4_1.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> (Reprinted with permission from Lehr, H., and Schmidt, M. [1995] “The LIGA Technique,” commercial brochure, IMM GmbH, Mainz-Hechtsheim.)
