| 摘要 |
PURPOSE:To reduce failure conduction for improvement of conductivity to a mother board without requiring the number of wasteful works of fabrication by uniformly arranging the tip ends of solder bumps by altering the heights of a plurality of solder bumps formed on the lower surface side of a printed resin substrate in response to the cup-shaped deformation of a semiconductor package. CONSTITUTION:Heights h1, h2, h3 of a plurality of solder bumps 11 formed on the lower surface side of a printed resin substrate 30 are made progressively higher as they go from the center to the outer periphery, in response to a cup- shaped bent of a semiconductor package, the bent being caused by a difference between contraction rates of the printed resin board 30 and resin 38 sealed through transfer molding. Hereby, even if the semiconductor package is bent into a cup shape, top ends of the solder bumps 11 formed into a matrix shape are uniformly arranged and hence are brought into uniform contact with the mother board 41. |
