<title>LIGA: metals, plastics, and ceramics</title>

Abstract

LIGA, an acronym from the German words for Lithography, Electroforming, and Molding, is being evaluated worldwide as a method to produce microparts from engineering materials. Much of the work to date in LIGA has focused on producing metal microparts, with nickel as the most common material of choice. There is a growing interest in producing plastic parts replicated from LIGA metal masters due largely to microanalytical instrumentation and medical applications. These plastic replicates are generally made by either hot embossing or injection molding. Ceramic replication, of particular interest fa high temperature applications or to produce piezoelectric or magnetic microparts, is also emerging as an area of interest. In this paper, a model of the LIGA exposure and development processes is presented along with the results of numerical optimization of mask design and process cost. The baseline processes for a cost-effective method to produce metal microparts are discussed, along with replication methods and results for plastics and ceramics.

Microscreen-based replication of electroforming micromolds

“…The microstamps used in these experiments were nickel plated on 3 inch (7.62 cm) diameter circular tool steel bases and were fabricated through the LIGA process at Sandia National Laboratories, Livermore, CA, as described elsewhere [11,12]. Stamps with either 95 or 170 micron deep features in a pattern containing gears, wedges, channels and other designs were used (Fig.…”

The mechanical properties, dimensional tolerance and microstructural characterization of micro-molded ceramic and metal components

“…The synchrotron patterned molds and all replicates were fabricated at Sandia National Laboratories, Livermore, CA, as described elsewhere [7]. Replicate micro-molds are much less expensive than those made directly by X-ray lithography since they do not require exposure to synchrotron radiation.…”

Microstructure and mechanical properties of nickel microparts electroformed in replicated LIGA molds

“…The microstamps used in these experiments were nickel plated on three inch diameter circular tool steel bases and were fabricated by the LIGA group at Sandia National Laboratories, Livermore, CA, as described elsewhere 11,12 . Two types of microstamps were used interchangeably for both the hot embossing and injection molding experiments.…”