US Patent 11252817 Printed wiring board and memory system

A printed wiring board includes first, second, and third wiring layers, first and second insulating members, and first and second vias. The first wiring layer includes a recognition mark and a first wiring on a first surface. The second wiring layer includes a first pad and a second wiring. The third wiring layer includes a third wiring. The first via penetrates the first insulating member and electrically connects the recognition mark to the first pad. The second via penetrates the second insulating member and electrically connects the first pad to the third wiring. The first pad and the first and second vias are in a region within an outer perimeter of the recognition mark when viewed from a direction orthogonal to the first surface.