A device includes a sensor die having a sensing region at a top surface of the sensor die, an encapsulant at least laterally encapsulating the sensor die, a conductive via extending through the encapsulant, and a front-side redistribution structure on the encapsulant and on the top surface of the sensor die, wherein the front-side redistribution structure is connected to the conductive via and the sensor die, wherein an opening in the front-side redistribution structure exposes the sensing region of the sensor die, and wherein the front-side redistribution structure includes a first dielectric layer extending over the encapsulant and the top surface of the sensor die, a metallization pattern on the first dielectric layer, and a second dielectric layer extending over the metallization pattern and the first dielectric layer.