Conductive via structure

Abstract

A conductive via structure includes a first dielectric layer, a conductive pad in the first dielectric layer, a second dielectric layer, and a redistribution layer. The second dielectric layer is disposed above the first dielectric layer and has an opening. The conductive pad is in the opening. The opening has a first width at a top surface of the second dielectric layer, a second width at a bottom surface of the second dielectric layer, and a third width between the top surface and the bottom surface of the second dielectric layer. A difference between the first and second width is in a range from about 3 um to about 6 um. The redistribution layer extends from the top surface of the second dielectric layer to the conductive pad. The third width is gradually decreased from the top surface to the bottom surface of the second dielectric layer.

Dependencies are inferred from the claim text.