Design rules for electroforming that avoid design flaws are presented. The physical background and interlink to the perceptions in the literature that sum up those rules are outlined. The characteristic dimensionless groups that are needed to identify the regime at which each electroforming process is run are summarized so that the relevance of each design rule can be determined. It is also shown how image possessing helps to visualize design flaws quickly, i.e., without the effort of a full simulation. All design rules do not rely on the details of the galvanic bath, but only on the knowledge of the flow regime and plating regime. Thus a first step to a simple design evaluation for the nonexpert is outlined.Fabrication of high quality products through the LIGA process ͑of deep X-ray lithography, electroforming, and plastic molding͒ 1 is a goal aimed for with increasing intensity. A main step in this process is the one of electroforming. The theoretical basis of this was already established in the mid-1900s. 2-4 More recent reviews were written by Dukovic 5 and Poon. 6 We find quite a few of analytical reports giving a rapidly increasing number of numerical results. However, up to now few attempts have been made to condense these to design rules so that the nonspecialist may start with a reasonable design and avoid the most obvious mistakes. Thus, we present a set of five design rules with an indication as when they should be applied, because the plating rates for different processes are dominated by different effects.Since the aim of this paper is not a review of electroforming we have not included the fields of auxiliary electrodes that are not on the wafer and anode-cathode assemblies and their effect on the uniformity. Both can have a pronounced effect on the overall uniformity of the plating result on the wafer, but are irrelevant most of the time for the uniformity on the feature scale typical for LIGA ͑sub-millimeter͒. We also do not address geometric leveling effects. These effects are relevant, e.g., for the leveling of V grooves, 2,7 however, they do not have much of an effect in plating processes related to X-ray lithography.We first present the physical background of electroforming, which helps us to understand the different current regimes. We also recapitulate the dimensionless numbers that allow discriminating the different regimes. In that context we also introduce a quantity that helps to identify the tertiary current, like the Wagner number does for the secondary current. Next we present the design rules and interlink these rules with the results found in the literature and show how to apply them. We also show how image processing can help to visualize design flaws quite rapidly.
