US Patent 7436072 Protected chip stack

A protected chip stack having a first chip and a second chip on the first chip. A functional layer in at least the first chip or the second chip. On the first chip and on the second chip there is in each case a connecting element, the connecting element on the first chip forming with the connecting element on the second chip a mechanical connection between the two chips. The connecting element and the functional layer are made of the same material. At least in the case of the first chip or in the case of the second chip, the connecting element is in direct contact with the functional layer.