Density distribution of conductive bumps on wafer

A wafer comprising:

• a substrate;
• and
• a plurality of conductive bumps on a surface of the substrate,
• wherein the conductive bumps include a plurality of first conductive bumps in a first area in said surface of the substrate and a plurality of second conductive bumps in a second area around the first area in said surface of the substrate, the first area having a plurality of effective chip areas arranged therein, the effective chip areas being chip areas out of which semiconductor chips are to be cut as products, the first conductive bumps being connected to a semiconductor integrated circuit and the second conductive bumps being connected to no semiconductor integrated circuit,
• in a plan view from a direction perpendicular to said surface of the substrate, an area density of the second conductive bumps in the second area is lower than an area density of the first conductive bumps in the first area, and
• the area density of the second conductive bumps in the second area continuously decreases at a constant rate as a distance from the first area increases.