| 摘要 |
PURPOSE:To prevent cracks and blisters in a prepreg laminate portion by etching some of crystal grains of surface-coarsened electrolytic copper after the surface of a copper foil is coarsened by crystal grains of an electrolytic copper. CONSTITUTION:The surface of a crystal grain 17 formed by plating electrolytic copper is further partially etched finely, and irregular fine crystal grains 17A are formed on the surface of a copper foil 13. In a copper foil having such irregular crystal grains, even if a board is subjected to an acid treatment in a pretreatment process before plating, its crystal grains are not dissolved, and its adhesion strength with a prepreg is enlarged. As a result, after lamination, no cracks or blisters occur in a process for soldering electronic parts to a board in a portion where a copper foil and prepreg are laminated. |
