Patent ID: 9439282
Filing Date: 2016-09-06
CPC Classification: H01L,H05K

Claim Text:
1. A method for manufacturing a printed circuit board, comprising: providing a core substrate comprising a first dielectric layer, the core substrate having an inner region and a trace region surrounding and connected with the inner region, the first dielectric layer having a first surface and a second surface opposite to the first surface; forming a first trace layer and a peelable metal layer on the first surface and forming a second trace layer on the second surface in the trace region, the peelable metal layer being formed in the inner region, the peelable metal layer having a smooth surface furthest away from the first surface; forming a photoresist layer on the smooth surface; roughening surfaces of the first trace layer and surfaces of the peelable metal layer uncovered by the photoresist layer; removing the photoresist layer from the smooth surface; laminating a second dielectric layer on the first trace layer and the peelable metal layer; forming a third trace layer on a surface of the second dielectric layer furthest away from the first dielectric layer; roughening surfaces of the third trace layer; laminating a fourth dielectric layer on the third trace layer and the second dielectric layer; forming a top trace layer on a surface of the fourth dielectric layer furthest away from the second dielectric layer; and along a boundary between the inner region and the trace region, defining a slit running through from the first dielectric layer to the second dielectric layer; separating the peelable metal layer from the second dielectric layer and removing the peelable metal layer and the first dielectric layer surrounded by the slit to form a cavity, the second dielectric layer exposed in the cavity.