Capacitor, resistor and inductor are passive components that occupy over 50% of board space and account for 70% of component counts in electronics. Despite the advances in silicon integrated circuits, the role of passives in the reduction of product size in mobile and handheld devices must be addressed. Reduction of assembly component count and improvement in handling can be achieved using integration techniques, but these networked passive arrays and integrated passive modules are for specific devices and are unsuited for general use. Instead of making integrated modules and arrays separately and then surface mounting the passive components, passives have been fabricated onto ceramic substrates and into ceramic modules. This low temperature co-fired ceramics (LTCC) technology has a hig...[ Read more ]

Capacitor, resistor and inductor are passive components that occupy over 50% of board space and account for 70% of component counts in electronics. Despite the advances in silicon integrated circuits, the role of passives in the reduction of product size in mobile and handheld devices must be addressed. Reduction of assembly component count and improvement in handling can be achieved using integration techniques, but these networked passive arrays and integrated passive modules are for specific devices and are unsuited for general use. Instead of making integrated modules and arrays separately and then surface mounting the passive components, passives have been fabricated onto ceramic substrates and into ceramic modules. This low temperature co-fired ceramics (LTCC) technology has a high processing temperature (850°C) and is unsuited for direct deployment onto organic substrates. A number of development efforts have been initiated to fabricate capacitors and resistors directly onto organic substrates. Developments in inductors had been focused on inductor coil geometry design and on the development of low temperature processable core materials. In this study, a Nickel Zinc Ferrite (NZF) sol-gel composite core material for organic substrates was formulated for low temperature processing. The effects of low temperature processing on the properties of the core were examined using a single spiral and two layer spiral inductor test vehicle. The inductance of the cored single layer spiral inductors and two layer spiral inductors are increased by 20% and 200% respectively. The increases in inductance resulting from addition of the new composite core with 20 wt% NZF powder loading are dramatically higher than that of a similarly loaded polymer-based NZF powder filled composite reported in literature. Instead, the new composite core enhanced inductor's properties are comparable to a polymer-based composite filled with 90wt% NZF powder. The changes in the chemistry and the microstructures as a function of processing were examined by XRD, TGA, DTA and SEM. The increase in inductive behavior was found to be associated with changes in the NZF composite as a function of the heat treatment. Increase in networked microstructure is identified to be the potential source of the large increase in inductance. Further increase in inductance may be achieved by increasing the network character of the composite core microstructure.