TWI666980B

The present invention provides a technology capable of reducing dimension of a large illuminated area made around a via hole aperture, when manufacturing a circuit board having a via hole of a fixed diameter using a technology of performing de-smear treatment under the state that a supporting object is attached to an insulating layer. The method for manufacturing the circuit board includes the processes of: (A) stacking a supporting object attached resin sheet including a plastic film supporting object and a resin composition layer bonded to the corresponding plastic film supporting object, on an inner layer substrate in order for the resin composition layer to be bonded to the inner layer substrate; (B) forming an insulating layer by annealing the resin composition layer, where adhesion strength of the corresponding insulating layer and the plastic film supporting object is 2 gf/cm ~ 18 gf/cm; (C) forming a via hole with a top diameter equal to or less than 40 μm on the insulating layer, by irradiating a las