Printed circuit board having solder ball mounting groove pads and a ball grid array package using such a board

Abstract

A ball grid array package includes a semiconductor chip 4, a circuit board 21 including a plurality of pattern layers of conductive wiring and dielectric layers interposed between the pattern layers which include the first pattern layer 22 and the second pattern layer 23. Electrically conductive wires are provided for interconnecting the semiconductor chip and the conductive wiring, mold resin 4 encapsulates the semiconductor chip and the wiring, and a plurality of solder balls 5 are adhered to a bottom surface of the circuit board 21 and electrically interconnected to the wires via the pattern layers. The surface mounting pad 22 is formed on the first pattern layer and a second conductive pad is formed on the second pattern layer. The first pattern layer is an outermost layer of the circuit board and the second pattern layer is just inside of the first layer so that the first and the second conductive pads form a solder ball groove mounting pad wherein a bottom surface of the mounting pad is the second conductive pad and the first conductive pad extends to the surface of the mounting pad.

Dependencies are inferred from the claim text.