Abstract: A method of sealing a ceramic lid on a ceramic semiconductor package with a high-power laser beam. As an aid to package assembly prior to the fusion of the package lid to the package body, a lid recess is created around the die installation cavity of the package body. Following the installation of a die within a package cavity, the package body is retrieved from a process tray by a pick and place robot and placed in a position locating fixture. The same robot then retrieves a ceramic lid from an automatic lid dispensing unit, and places it within the lid recess of the package body. With the lid positioned within the recess, a Yttrium-Aluminum-Garnet (YAG) laser with beam splitter optics is moved by an X-Y table arm precisely over the top of the package. Moving with a linear speed of approximately 2.1 cm/sec. and with a power setting of approximately 170 watts, the split beam YAG laser simultaneously fuses a pair of opposite edges of the lid to the adjacent edges of the recess.

Abstract: A printed circuit board is designed to conform to a single in-line memory module (SIMM) configuration, but includes multiple rows of the memory devices. By controlling a sequence of enable signals, selection of a single row from the multiple row of memory devices can be accomplished. The ability to address the different rows multiplies the memory capacity of the board by the number of rows of memory devices.