Abstract: A process for the etching of multiple layers of at least two different metals comprisies: forming a resist pattern over a first layer of metal, said resist pattern having a pattern of openings therein, applying a first etch solution onto said resist pattern so that at least some etch solution contacts exposed areas of the first layer of metal, etching away the majority of the depth of the first metal in exposed areas of metal in the first layer of metal, applying a second etch solution onto the resist pattern the second etch solution having a rate of etch towards the first metal as compared to the first etch solution that is at least 20% less than the millimeter/minute rate of etch of the first etch solution at the same etch solution temperature, removing the second etch solution from said resist pattern after at least the first metal layer has been etched sufficiently to expose areas of a second metal layer underlying the first metal layer by forming an etched first metal layer, and applying a third etch so

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.

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.