摘要 |
A packaging system for a high current, low voltage power supply. The power supply uses bare die power FETs which are directly mounted to a thermally conductive substrate by a solder attachment made to the drain electrode metallization on the back side of the FETs. The source electrode and gate electrode of each FET are coupled to the circuitry on an overhanging printed circuit board, using CSP solder balls affixed to the front side of the FET die. The heat generated by the FETs is effectively dissipated by the close coupling of the FETs to the thermally conductive underlying substrate. High interconnect densities are achieved through the use of a multilayer printed circuit board. This high interconnect density, with the addition of a magnetic core element, allows the power supply packaging system to incorporate transformer windings for an isolation transformer or an inductor.
|