Förfarande för etsning, samt ramelement, mask och prefabricerat substratelement för användning vid sådan etsning

摘要

A resist coating is applied on the metal film (3) formed on the substrate (1). The central circuit portion (4) of the substrate is etched electrochemically in a specified pattern to form individual circuits (5). A frame (9) is mounted on the substrate before etching such that it is adjacent to the central portion to attract the electrical field and prevent excessive densities at the periphery of the central portion during etching. Independent claims are also included for the following: (a) Frame element; (b) Mask; (c) Prefabricated substrate element