Embedded magnetics for microprocessor and multichip modules integrated power - art. no. 10Q701

摘要

A new transformer/inductor technology is introduced which is suitable for integrated power for multichip modules (MCM) and microprocessors. The transformer/inductor is embedded within the ceramic substrate, as are the chips and other components. For core, multipole core structures are employed in order to meet extremely low height requirements. The windings are constructed using high-density interconnect techniques such as laminating dielectric layers and depositing winding metals using sputtering followed by electroplating. Winding patterns are etched using photoresist and wet etching techniques, and multiple vias are used to connect different primary and secondary winding layers. A conformal metal mask is used to laser-drill through (large) holes for the posts of the top part of the core. An experimental 50-W, six-pole embedded transformer is described. It operates at 1.0 MHz with an efficiency approaching 98.7 and has a net height of less than 0.09 in. It provides for extremely tight secondary side circuit layouts with very low and fixed leakage inductance. (c) 2005 American Institute of Physics.