CIRCUIT BOARD SURFACE STRUCTURE AND FABRICATION METHOD THEREOF

摘要

A circuit board surface structure and a fabrication method thereof are proposed. The circuit board surface structure includes: a circuit board having a plurality of electrically connecting pads formed on at least one surface thereof; a first and a second insulating protective layers formed on the surface of the circuit board in sequence; first and a second openings respectively formed in the first and second insulating protective layers to expose the electrically connecting pads on the surface of the circuit board, wherein the first and second openings have narrow top and wide bottom and the diameter of the first openings is bigger than that of the second openings; and conductive elements formed in the first and second openings on surfaces of the electrically connecting pads. The present structure facilitates to strengthen the bonding between the conductive elements and the corresponding electrically connecting pads.