US Patent 7145248 Common connection method for flip-chip assembled devices

The planes of chips in a flip-chip arrangement, when at least one of the chips has an insulating layer running through it, may be electrically connected together by incorporating into the top chip a flexible metalized structure which is pinned to the top layer of the bottom chip using a wire bond ball which is connected to a wire that is attached to a pad on the top layer of the upper chip. A single connection connects both layers of the top chip to the layer on the bottom chip. The flexible structure may be similar to a collapsible cup with a hole in the middle or it may be a tiltable micro mirror.