A stacked unit comprising: a first microelectronic element having a first rear surface; a second microelectronic element having a second rear surface, the second microelectronic element attached to the first microelectronic element so as to form an individual stacked unit; wherein in said individual stack unit the second microelectronic element overlies the first microelectronic element such that the first rear surface of the first microelectronic element faces toward the second rear surface of the second microelectronic element; and at least one bridging element, wherein the first microelectronic element and second microelectronic element each have a front surface (14, 14a) and a plurality of contacts exposed thereat, said contacts also being exposed contacts of the individual stacked unit for connection to a substrate or a further stacked unit, wherein the at least one bridging element extends between the plurality of contacts of the first microelectronic element and the plurality of contacts of the second microelectronic element so as to electrically connect the two, wherein the first and second microelectronic elements (12, 12a) each include a first exposed edge and a second exposed edge extending from the front surface (14, 14a) to the rear surface (16, 16a) of the microelectronic element, wherein the first exposed edge of the first microelectronic element is aligned with the first exposed edge of the second microelectronic element, thereby forming a first sidewall of said individual stacked unit, wherein the second exposed edge of the first microelectronic element is aligned with the second exposed edge of the second microelectronic element, thereby forming a second sidewall of said individual stacked unit, and wherein the first and second microelectronic elements each include a third and a fourth exposed edge extending from the front surface to the rear surface of the microelectronic element, wherein the third exposed edge of the first microelectronic element is aligned with the third exposed edge of the second microelectronic element, thereby forming a third sidewall of said individual stacked unit, and wherein the fourth exposed edge of the first microelectronic element is aligned with the fourth exposed edge of the second microelectronic element, thereby forming a fourth sidewall of said individual stacked unit; wherein the at least one bridging element is formed on the first sidewall. a first microelectronic element having a first rear surface; a second microelectronic element having a second rear surface, the second microelectronic element attached to the first microelectronic element so as to form an individual stacked unit; wherein in said individual stack unit the second microelectronic element overlies the first microelectronic element such that the first rear surface of the first microelectronic element faces toward the second rear surface of the second microelectronic element; and at least one bridging element, wherein the first microelectronic element and second microelectronic element each have a front surface (14, 14a) and a plurality of contacts exposed thereat, said contacts also being exposed contacts of the individual stacked unit for connection to a substrate or a further stacked unit, wherein the at least one bridging element extends between the plurality of contacts of the first microelectronic element and the plurality of contacts of the second microelectronic element so as to electrically connect the two, wherein the first and second microelectronic elements (12, 12a) each include a first exposed edge and a second exposed edge extending from the front surface (14, 14a) to the rear surface (16, 16a) of the microelectronic element, wherein the first exposed edge of the first microelectronic element is aligned with the first exposed edge of the second microelectronic element, thereby forming a first sidewall of said individual stacked unit, wherein the second exposed edge of the first microelectronic element is aligned with the second exposed edge of the second microelectronic element, thereby forming a second sidewall of said individual stacked unit, and wherein the first and second microelectronic elements each include a third and a fourth exposed edge extending from the front surface to the rear surface of the microelectronic element, wherein the third exposed edge of the first microelectronic element is aligned with the third exposed edge of the second microelectronic element, thereby forming a third sidewall of said individual stacked unit, and wherein the fourth exposed edge of the first microelectronic element is aligned with the fourth exposed edge of the second microelectronic element, thereby forming a fourth sidewall of said individual stacked unit; wherein the at least one bridging element is formed on the first sidewall.