Abstract: A method of making printed circuit boards having gold dot contacts formed on the terminal pads is disclosed. A first layer of copper is overlayed with a pattern of tin or solder which acts as a resist. The gold dot contacts are resistance welded to the terminal pads. The copper underlayment and its pattern of tin or solder carrying the gold dots is then bonded to an electrically insulating substrate, which can be flexible, to form a composite board which is then etched to form a printed circuit board having gold dot contacts thereon. Other materials than tin or solder can be employed so long as there is a difference in etchability between it and the copper foil.

Abstract: A residue-free plasma etch of high temperature aluminum copper metallization is provided by the use of a single plasma etcher. The metallization layer is covered by a protective oxide layer. This structure is then placed in the single etcher and a vacuum is established. The protective oxide layer is then etched and without breaking the vacuum or removing the structure from the etcher the metal layer is also etched. This results in the etched surface being residue-free.