Biased acid cleaning of a copper-invar-copper laminate

An electrical circuit structure, comprising:

• an electrical circuit element, including:
• a power supply for generating a voltage output;
• a copper-ferronickel-alloy (CFC) laminate having an INVAR layer sandwiched between a first copper layer and a second copper layer, wherein the CFC laminate is electrically coupled to a negative terminal of the power supply;
• and
• a conductive anode electrically coupled to a positive terminal of the power supply;
• and
• an acid solution, wherein the CFC laminate and the conductive anode are immersed in the acid solution.

A method for immersing a metal structure in an acid solution without forming a pocket void in the metal structure, comprising the steps of:

• selecting the metal structure from the group consisting of an iron-nickel alloy and a noble metal structure, wherein the noble metal structure includes a second iron-nickel alloy conductively coupled to a metal that is more noble than the second iron-nickel alloy;
• forming an electrical circuit element including:
• a power supply;
• the metal structure electrically coupled to a negative terminal of the power supply;
• and
• a conductive anode electrically coupled to a positive terminal of the power supply;
• turning on the power supply to a voltage output;
• and
• immersing the metal structure and the conductive anode in the acid solution.

An electrical circuit structure, comprising:

• an electrical circuit element, including:
• a power supply for generating a voltage output;
• a metal structure electrically coupled to a negative terminal of the power supply, wherein the metal structure is selected from the group consisting of an iron-nickel alloy and a noble metal structure, wherein the noble metal structure includes a second iron-nickel alloy conductively coupled to a metal that is more noble than the second iron-nickel alloy;
• and
• a conductive anode electrically coupled to a positive terminal of the power supply;
• and
• an acid solution, wherein the metal structure and the conductive anode are immersed in the acid solution.