FUTURE MANUFACTURING TECHNIQUES FOR STACKED MCM INTERCONNECTIONS

As multichip modules (MCMs) grow in chip count and complexity, increas ingly large numbers of input/output (I/O) channels will be required fo r connection to other MCMs or printed wiring boards. In applications s uch as digital signal processing, large increases in processing densit y (number of operations in a given volume) can be obtained in stacked MCM arrangements. The potential pin counts and required I/O densities in these stacked architectures will push beyond the limits of present interlevel coupling techniques. This problem is particularly acute if easy separation of layers is needed to meet MCM testing and yield requ irements. Solutions to this problem include the use of laser-drilled, metal-filled electrical vias in the MCM substrate and also optoelectro nic data channels that operate in large arrays. These arrays will emit and detect signals traveling perpendicular to the surface of the MCM. All of these approaches will require packaging and alignment that mak es use of advanced MCM manufacturing techniques.