摘要 |
Process of preparing copper foil for use in fine geometry circuit boards in which spaced apart islands are formed in the copper foil, with the islands being smaller in dimension than crystals in the foil so that most of the islands are single crystals, and the islands are grown out until they meet one another to form a continuous foil having a columnar structure that etches preferentially along the intersections of the islands in directions perpendicular to the surface of the foil thus formed.
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