摘要 |
A chip stack employing BGA or FBGA integrated circuit chip packages is provided. Two chip packages have bottom surfaces attached with sets of electrical contacts, which are oriented towards each other and are electrically connected to conductive patterns formed within the same flex substrate. One set contacts a conductive pattern on a top surface, the other set contacts a pattern on a bottom surface of the flex substrate within a same end portion. The other end portion has a conductive pattern, and is connected to a third set of electrical contacts. The flex substrate is wrapped around an edge of the chip package to connect the third set with the other two sets. Thereby, four chip packages are provided with this design, the layout of conductive traces formed within at least one of the flex substrates is meandered to compensate for length differences with respect to the other flex substrate.
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