In one embodiment, a circuit substrate comprises a substrate; and a warpage preventing pattern disposed on the substrate. The warpage preventing pattern comprises a first pattern at a first corner of the substrate and a second pattern at a second corner of the substrate. The first corner and the second corner are disposed adjacent to each other. An overall orientation of the first pattern is different from an overall orientation of the second pattern with respect to the substrate. The warping of a semiconductor package can be significantly reduced by cutting off stress lines in the corners of the circuit substrate. Various configurations and orientations of the warpage preventing pattern are provided in order to effectively block stress concentration in the corners of the circuit substrate.