摘要 |
A wafer having a front face formed with a functional device is irradiated with laser light while positioning a light-converging point within the wafer with the rear face of the wafer acting as a laser light incident face, so as to generate multiphoton absorption, thereby forming a starting point region for cutting due to a molten processed region within the wafer along a line. Consequently, a fracture can be generated from the starting point region for cutting naturally or with a relatively small force, so as to reach the front face and rear face. Therefore, when an expansion film is attached to the rear face of the wafer by way of a die bonding resin layer after forming the starting point region for cutting and then expanded, the wafer and die bonding resin layer can be cut along the line.
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