Lamination of circuit sub-elements while assuring registration

Abstract

A process for the formation of an article having multiple electrical circuits comprises: providing a first sub-element comprising in sequence a first metal layer of copper in electrical contact with a second metal layer of aluminum in electrical contact with a third metal layer of copper; etching an electrical circuit design in the first metal layer and in a separate etch step, etching away at least 10%, but less than 100% of the second metal layer to provide electrical connections between the first metal layer and the third metal layer; etching an electrical circuit design into the third metal layer; adhering an etched surface comprising the circuit design of the first or third metal layer to a first surface of a support layer to form a circuit board. The process may etch the first and third metal layers simultaneously or sequentially. After adhering an etched surface comprising the circuit design of the first or third metal layer in registration to a support layer to form a circuit board, an additional step may be performed, which additional step is selected from the group consisting of: a) adhering an etched surface of a second tri-metal subelement to a second surface of the support layer and b) adhering a second support layer to said third or first metal layer, respectively, and adhering an etched surface of a second tri-metal subelement to the second support layer. The registration between layers may be effected by visual, mechanical, optical or electronic systems with visually or mechanically readable registration marks, radiation through holes, and/or posts used for identifying positions of desired registration between layers.

Dependencies are inferred from the claim text.