A method for making a microelectronic assembly includes providing a microelectronic element with first conductive elements and a dielectric element with second conductive elements. At least some of either the first conductive elements or the second conductive elements may be conductive posts and other of the first or second conductive elements may include a bond metal disposed between some of the conductive posts. An underfill layer may overly some of the first or second conductive elements. At least one of the first conductive elements may be moved towards the other of the second conductive elements so that the posts pierce the underfill layer and at least deform the bond metal. The microelectronic element and the dielectric element can be heated to join them together. The height of the posts above the surface may be at least forty percent of a distance between surfaces of the microelectronic element and dielectric element.