Patent ID: 9439281
Filing Date: 2016-09-06
CPC Classification: H05K

Claim Text:
1. A method for manufacturing a printed circuit board, comprising: providing a circuit substrate, the circuit substrate comprising a base and a plurality of conductive pads; forming a dielectric layer on a surface of the conductive pads and a surface of the base exposed from the conductive pads, the dielectric layer comprising a laser-activated catalyst; forming a first metal seed layer on a surface of the dielectric layer furthest from the circuit substrate; forming a photoresist layer on a surface of the first metal seed layer furthest from the dielectric layer, the photoresist layer comprising a trace portion; exposing the trace portion of the photoresist layer; defining a plurality of blind vias in the photoresist layer, the first metal seed layer, and the dielectric layer using a laser, the blind vias spatially corresponding to the conductive pads, each conductive pad exposed from a corresponding blind via, the laser-activated catalyst at a wall of the blind via being activated by laser, thereby obtaining an activated metal layer; forming a second metal seed layer on the activated metal layer, the second metal seed layer being electrically connected to the first metal seed layer; removing the trace portion of the photoresist layer by developing to form a trace opening, and a portion of the first metal seed layer being exposed from the trace opening; forming a metal bump in each blind via and forming a trace in the trace opening by electroplating, the metal bump protruding the surface of the dielectric layer furthest from the circuit substrate; and removing the first metal seed layer uncovered by the trace and the photoresist layer, thereby obtaining a printed circuit board.