Patent ID: 9603263
Date: 2017-03-21
CPC Classifications: H05K,Y10T

Claim:
1. A manufacturing method of a circuit substrate, comprising: bonding peripheries of two metal layers to form a sealed area, wherein each of the two metal layers comprises a first copper foil layer and a second copper foil layer, and a thickness of each of the second copper foil layers is substantially greater than a thickness of each of the first copper foil layers, and the second copper foil layers are bonded to each other; forming at least a through hole passing through the sealed area; forming two insulating layers on the two metal layers, and forming two conductive layers on the two insulating layers; laminating the two insulating layers and the two conductive layers to the two metal layers, wherein the two metal layers bonded to each other are embedded between the two insulating layers, and the two insulating layers are filled into the through hole; separating the sealed area of the two metal layers to form two separated circuit substrates; and removing the second copper foil layers from each of the two separated circuits by a lift-off method, wherein the lift-off method comprises peeling off the second copper foil layer from the first copper foil layer.