The present invention is directed to a structure for packaging electronic devices, such as semiconductor chips, in a three dimensional structure which permits electrical signals to propagate both horizontally and vertically. The structure is formed from a plurality of assemblies. Each assembly is formed from a substrate having disposed on at least one surface a plurality of electronic devices. Each assembly is disposed in a stack of adjacent assemblies. Between adjacent assemblies there is an electrical interconnection electrically interconnecting each assembly. The electrical interconnection formed from an elastomeric interposer having a plurality of apertures extending therethrough. The array of apertures corresponds to the array of electronic devices on the substrates. The aperture and electrical interconnection is disposed over the array of electronic devices so that the electrical interconnection between adjacent electronic devices. The stack of assemblies is compressed thereby compressing the electrical interconnection between adjacent assemblies. Methods for fabricating the electrical interconnection as a stand alone elastomeric sheet are described.