SURFACE MOUNTING PAD HAVING HOLE FOR ENHANCING ADHESION

摘要

PROBLEM TO BE SOLVED: To enhance reliability and maintainability by providing a circuit layer directly under an insulation layer with a dummy pattern sufficiently larger than a through hole made in the insulation layer at a position facing the through hole and connecting the circuit layer with the dummy pattern through the through hole thereby enhancing adhesion of a surface mounting pad. SOLUTION: In order to protect the wiring properties of same circuit layer 6 as much as possible, a dummy pattern 4 of a circuit layer 6 formed on a substrate 101 is arranged with circles having diameter of 120μm and the size of a through hole (diameter of aperture) made in an insulation layer 3 is set at 100μm which is equal to that of other via and smaller than that of the dummy pattern 4. A surface mounting pad 1 is formed by electroless copper plating at the size of 700μm and a through hole 2 plated simultaneously with the dummy pattern 4 in that region. The surface mounting pad 1, the through hole 2 and the dummy pattern 4 are connected not electrically but mechanically and density strength of the surface mounting pad 1 is enhanced.