摘要 |
The invention is an aluminum etchant and method for chemically milling aluminum, according to one embodiment, from a copper-aluminum-copper tri-metal layer to form electronic circuits. The tri-metal comprises copper circuit patterns present on opposing surfaces of an aluminum foil, one of the copper patterns being laminated on a substrate. The etchant comprises an aqueous solution of 50 to 500 g/l base selected from (a) sodium hydroxide, (b) potassium hydroxide, and (c) their mixture; and 60 to 500 g/l nitrate salt. The method comprises contacting the tri-metal with the etchant at a temperature between 25 and 95 DEG C. for a time sufficient to remove a desired amount of the aluminum layer and provide electronic circuitry (rigid/flexible/3-dimensional circuitry) which contains multiple conductive circuit layers.
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