Metal substrate and surface treatment method

Abstract

A metal substrate and a surface treatment method. The surface treatment method includes: immersing a copper foil substrate in a first plating solution to perform a first chemical plating procedure to form a first silver layer on the copper foil substrate, and immersing the copper foil substrate in a second plating solution to perform a second chemical plating procedure to form a second silver layer on the first silver layer. The first plating solution includes a silver-containing precursor, a chelating agent, a polyol, and a reducing agent, and the second plating solution includes a silver-containing precursor, a chelating agent, a polyol, a reducing agent, and a carboxyl-containing long carbon chain organic compound. A concentration of the carboxyl-containing long carbon chain organic compound in the second plating solution ranges from 2 ml/L to 5 ml/L. An arithmetic mean roughness of the second silver layer is less than 0.1 μm.

Dependencies are inferred from the claim text.