Patent ID: 9066458
Filing Date: 2015-06-23
Classification: H01L,H05K,Y02P

Abstract:
1. A method of fabricating a circuit board, comprising: providing a core substrate having a first surface and a second surface opposite to the first surface; forming a first patterned photoresist layer on the first surface; forming a second patterned photoresist layer on the second surface; plating a first patterned conductive layer on the first surface exposed by the first patterned photoresist layer, wherein the first patterned conductive layer has a first pad, the first pad extends in a plane where the first patterned conductive layer extends, and the first pad is configured to connect to a mother board of an electronic device; plating a second patterned conductive layer on the second surface exposed by the second patterned photoresist layer, wherein the second patterned conductive layer has a second pad, and the second pad is configured to connect to a chip; forming a third patterned photoresist layer on the first patterned photoresist layer and the first patterned conductive layer, wherein the third patterned photoresist layer exposes the first pad; forming a fourth patterned photoresist layer on the second patterned photoresist layer and the second patterned conductive layer, wherein the fourth patterned photoresist layer exposes the second pad; plating a first extending pad on the first pad exposed by the third patterned photoresist layer; plating a second extending pad on the second pad exposed by the fourth patterned photoresist layer; removing the first patterned photoresist layer, the second patterned photoresist layer, the third patterned photoresist layer and the fourth patterned photoresist layer; forming a first thermal-curing type dielectric layer on the first surface, wherein the first thermal-curing type dielectric layer covers the first patterned conductive layer and the first extending pad and entirely exposes a top surface of the first pad, and all side surfaces of the first pad is surrounded by the first thermal-curing type dielectric layer; forming a second thermal-curing type dielectric layer on the second surface, wherein the second thermal-curing type dielectric layer covers the second patterned conductive layer and the second extending pad; removing a portion of the first thermal-curing type dielectric layer covering a top of the first extending pad; removing a portion of the second thermal-curing type dielectric layer covering a top of the second extending pad, wherein a thickness of the second thermal-curing dielectric layer is smaller than a sum of a thickness of the second pad and a thickness of the second extending pad, and the second extending pad completely fills the second thermal-curing dielectric layer for the second thermal-curing dielectric layer to expose the second extending pad; and removing the first extending pad.