Device, package structure and method of forming the same are disclosed. The device includes a die encapsulated by an encapsulant, a conductive structure aside the die, and a dielectric layer overlying the conductive structure. The conductive structure includes a through via in the encapsulant, a redistribution line layer overlying the through via, and a seed layer overlying the redistribution line layer. The dielectric layer includes an opening, wherein the opening exposes a surface of the conductive structure, the opening has a scallop sidewall, and an included angle between a bottom surface of the dielectric layer and a sidewall of the opening is larger than about 60 degrees.