An example method includes providing a packaging device includes a substrate having an integrated circuit die mounting region. A plurality of microstructures, each including an outer insulating layer over a conductive material, are disposed proximate a side of the integrated circuit die mounting region. An underfill material is disposed between the substrate and the integrated circuit die, the microstructures preventing spread of the underfill. In another example method, a via can be formed in a substrate and the substrate etched to form a bump or pillar from the via. An insulating material can be formed over the bump or pillar. In another example method, a photoresist deposited over a seed layer and patterned to form openings. A conductive material is plated in the openings, forming a plurality of pillars or bumps. The photoresist and exposed seed layer are removed. The conductive material is oxidized to form an insulating material.