A microelectronic assembly may include a substrate having an opening extending between first and second oppositely facing surfaces of the substrate, the opening elongated in a first direction; and at least one microelectronic element having a front face facing and attached to the first surface of the substrate and a plurality of contacts at the front face overlying the opening, the microelectronic element having first and second opposite peripheral edges extending away from the front face. The first peripheral edge extends beyond, or is aligned in the first direction with, an inner edge of the opening, and the opening extends beyond the second peripheral edge.