Abstract: A printed circuit board structure includes a printed circuit board having a conductive structure, a dielectric structure and a copper foil layer. The copper foil layer has a first sub-copper foil layer and a second sub-copper foil layer on the printed circuit board. The dielectric structure and the first sub-copper foil layer have an opening. The opening exposes the conductive structure. A conductive bump is on the first sub-copper foil layer and in the opening, and the conductive bump is electrically connected to the conductive structure. A recess is between the first sub-copper foil layer and the second sub-copper foil layer, and the top surface of the second sub-copper foil layer is exposed. A method of forming the structure above is also provided.

Abstract: A package structure that includes a first redistribution structure and a second redistribution structure is provided. The first redistribution structure includes a first dielectric layer, and a first redistribution circuit in the first dielectric layer. The second redistribution structure includes a first portion on the first redistribution structure and a second portion on the first portion, and each of the portions is electrically connected to the first redistribution structure and the first portion, respectively. The circuit density of the second portion is lower than that of the first portion. The first portion includes a second dielectric layer having a second redistribution circuit therein. The second portion includes a third dielectric layer having a third redistribution circuit therein. The third dielectric layer has a stiffener layer, which is separated from the third redistribution circuit by the third dielectric layer. A method of forming a package structure is also provided.