A microelectronic assembly comprising: a first substrate having a first surface; a second substrate having a second surface facing and separated by a first distance from the first surface; a microelectronic element arranged in a space between said first and second surfaces (22, 24), said first microelectronic element being affixed to and separated by a second distance from the first surface, said second distance being shorter than said first distance; a first thin conductive element exposed at the first surface and having a first face comprising first and second regions; a first conductive projection having a base connected to and covering the first region of the first face and extending to an end remote therefrom; a first dielectric material layer covering the second region of the first thin conductive element and contacting at least the base of the first conductive projection; a second thin conductive element exposed on the second surface and having a second face, wherein the second face of the second thin conductive element comprises first and second regions; a second conductive projection extending away from the second surface towards the first surface and having a base defining a periphery and connected to and covering the first region of the second thin conductive element and an end portion remote from the base; a second dielectric material layer covering the second region of the second thin element; a fusible metal mass contacting and extending between the first and second dielectric material layers (40, 41) and connecting the first projection to the second projection such that the first region of the first face is oriented toward the second face of the second thin conductive element, wherein the mass extends along an edge of the first projection towards the first dielectric material layer. a first substrate having a first surface; a second substrate having a second surface facing and separated by a first distance from the first surface; a microelectronic element arranged in a space between said first and second surfaces (22, 24), said first microelectronic element being affixed to and separated by a second distance from the first surface, said second distance being shorter than said first distance; a first thin conductive element exposed at the first surface and having a first face comprising first and second regions; a first conductive projection having a base connected to and covering the first region of the first face and extending to an end remote therefrom; a first dielectric material layer covering the second region of the first thin conductive element and contacting at least the base of the first conductive projection; a second thin conductive element exposed on the second surface and having a second face, wherein the second face of the second thin conductive element comprises first and second regions; a second conductive projection extending away from the second surface towards the first surface and having a base defining a periphery and connected to and covering the first region of the second thin conductive element and an end portion remote from the base; a second dielectric material layer covering the second region of the second thin element; a fusible metal mass contacting and extending between the first and second dielectric material layers (40, 41) and connecting the first projection to the second projection such that the first region of the first face is oriented toward the second face of the second thin conductive element, wherein the mass extends along an edge of the first projection towards the first dielectric material layer.