An interposer substrate includes a first circuit pattern embedded at a first surface of a dielectric layer and a second circuit pattern embedded at a second surface of the dielectric layer; a middle patterned conductive layer in the dielectric layer between the first circuit pattern and the second circuit pattern; first conductive vias, where each first conductive via includes a first end adjacent to the first circuit pattern and a second end adjacent to the middle patterned conductive layer, wherein a width of the first end is greater than a width of the second end; second conductive vias, where each second conductive via including a third end adjacent to the second circuit pattern and a fourth end adjacent to the middle patterned conductive layer, wherein a width of the third end is greater than a width of the fourth end.