The invention relates to a semiconductor structure and a manufacturing method thereof. The semiconductor structure includes a substrate; a die disposed over the substrate, and including a die pad, a conductive via disposed over the die pad and a dielectric material surrounding the conductive via; a molding disposed over the substrate and surrounding the die; a lower dielectric layer disposed nearer the substrate and over the dielectric material and the molding; and an upper dielectric layer disposed further the substrate and over the lower dielectric layer, wherein a material content ratio inthe upper dielectric layer is substantially greater than that in the lower dielectric layer, and the material content ratio substantially inversely affects a mechanical strength of the upper dielectric layer and the lower dielectric layer.