Substrate structure and manufacturing method thereof

A manufacturing method of a substrate structure, comprising steps of:

• (i) forming a first circuit structure, wherein the first circuit structure comprises:
• a first layer comprising a first dielectric layer and a first circuit layer, wherein the first circuit layer is embedded in the first dielectric layer;
• and
• a second layer disposed below the first layer and having a second circuit layer, wherein the second circuit layer is electrically connected to the first circuit layer;
• (ii) forming a pyrolysis layer on the first circuit structure, wherein the pyrolysis layer has a melting point lower than a melting point of the first dielectric layer;
• (iii) forming a first metal layer on a laser drilling area of the pyrolysis layer;
• (iv) forming a preceding second circuit structure on the pyrolysis layer and the first metal layer;
• (v) in an orthogonal projection direction of the laser drilling area, performing a laser drilling process to the preceding second circuit structure and the pyrolysis layer so as to form a second circuit structure, a second dielectric layer, and a defective film, wherein the second circuit structure comprises a third circuit layer electrically connected to the first circuit layer, and the defective film is disposed between the first metal layer and the first circuit structure;
• and
• (vi) removing the first metal layer and the defective film.