Patent ID: 10134665

Abstract:
A BGA 9 includes a wiring substrate 2, a semiconductor chip 1 fixed on the wiring substrate 2, a sealing body 4 that seals the semiconductor chip 1, and a plurality of solder balls 5 provided on a lower surface of the wiring substrate 2. A degree of flatness of an upper surface 2ia of a first wiring layer 2i of the wiring substrate 2 of the BGA 9 is lower than a degree of flatness of a lower surface 2ib, and a first pattern 2jc provided in a second wiring layer 2j is arranged at a position overlapping a first pattern 2ic provided in the first wiring layer 2i. Also, an area of the first pattern 2ic provided in the first wiring layer 2i is larger than an area of a plurality of (for example, two) second patterns 2jd provided in the second wiring layer 2j in a plan view, and a first opening portion 2jm through which a part of a second insulating layer 2h is exposed is formed in the first pattern 2jc provided in the second wiring layer 2j.