Semiconductor device and manufacturing method thereof

A method of manufacturing semiconductor devices, wherein a resin sealing structure comprises an interconnection substrate board, semiconductor chips mounted on said interconnection substrate board, a heat radiation plate arranged above said semiconductor chips, and sealing resin provided between said heat radiation plate and said interconnection substrate board, the method comprising:

• cutting said heat radiation plate by a plate cutting blade in a first direction along a first heat radiation plate cutting line;
• cutting said heat radiation plate by said plate cutting blade in a second direction orthogonal to the first direction along a second heat radiation plate cutting line orthogonal to the first heat radiation plate cutting line, after said cutting said heat radiation plate by said plate cutting blade in the first direction;
• and
• cutting said interconnection substrate board and said sealing resin along first and second interconnection substrate board cutting lines by a substrate board cutting blade in the first direction and the second direction, respectively, to divide said resin sealing structure into said semiconductor devices,
• wherein each of said semiconductor devices comprises an interconnection substrate, said semiconductor chip mounted on said interconnection substrate, said sealing resin provided to cover said semiconductor chip and said interconnection substrate, and a heat radiator,
• wherein said second heat radiation plate cutting line and said second interconnection substrate board cutting line correspond to each other in position in a third direction orthogonal to the first direction and the second direction, and
• wherein said first heat radiation plate cutting line is displaced from said first interconnection substrate board cutting line by a preset displacement amount in a direction opposite to the second direction.