Middle-permittivity dielectric compositions are necessary to realize various distributed circuit components in Low temperature co-fired ceramics (LTCC) structures. In this study, we are reporting some dielectric compositions the permittivity range of which are in the range of 20-60. Various borosilicate-based glass compositions were added to two kinds of middle-k commercial dielectric compositions to get the densification temperatures of lower than 875 degreesC. The effects of the composition and the amount of borosilicate-based glass systems on the densification and the microwave properties were examined. (C) 2004 Elsevier B.V. All rights reserved.