Yield enhancement for stacked chips through rotationally-connecting-interposer

[0026]FIGS. 2-4 are various views of a first exemplary structure according to the present invention. The first exemplary structure includes a vertical stack, from bottom to top, of a first substrate 10, an interposer 30, and a second substrate 20. FIG. 2 is a top-down view of the first exemplary structure in which the second substrate 20 is not shown for clarity. FIG. 3 is a vertical cross-sectional view of the first exemplary structure along a flat vertical plane X-X′ shown in FIG. 2. FIG. 3 is a vertical cross-sectional view of the first exemplary structure along a curved vertical plane Y-Y′ shown in FIG. 2.

[0027]The first exemplary structure enables testing of a functionality that requires operation of a component in the first substrate 10 and another component in the second substrate 20 by providing electrical connections between the first substrate 10 and the second substrate 20 in the interposer 30. The interposer 30 enables testing of the combination of the first substrate 10 an

[0055]FIG. 12 a flow chart illustrates processing steps according to the present invention. Referring to step 410, an interposer is provided, which provides electrical connections between a first substrate and a second substrate. The interposer may provide electrical connections between the first and second substrates without any rotation between the first and second substrates, or may provide electrical connections between the first and second substrates with a rotational angle of (i−1) / N×2π in which N is an integer greater than 1, and i is an integer from 2 and N.

[0056]Referring to step 420, a first substrate including first semiconductor chips and a second substrate including second semiconductor chips are provided. The first semiconductor chips are arranged to have an N-fold rotational symmetry around a center axis of the first substrate. The second semiconductor chips are arranged to have an N-fold rotational symmetry around a center axis of the second substrate. Further, the fi