Characterization of dielectric LTCC tapes

Low Temperature Co-Fired Ceramic (LTCC) technology is one of the most widely used technologies for producing reliable electronic components, modules, and sensors, capable for working in high temperature applications and applications requiring low dielectric losses. In this paper characterization of two dielectric LTCC tapes (Heraeus AHT 01-005 and Heraeus AHT 08-047) is presented. The virtual relative permittivity of LTCC tapes as well as its dependence on temperature is presented in the paper. An investigation on weight loss before and after tape firing, material shrinkage, and surface roughness for both LTCC tapes is given. Material reliability in water environment is also investigated and reported. For this purpose, an interdigital capacitor (IDC) was embedded between four, six, and eight layers of LTCC tape, in which the IDC is buried in the middle of the structure. Sensing structures were placed in tap water and the capacitance of the buried IDC was measured over a period of 200 days. The most of the IDC structures buried inside were unaffected by water which is surrounding the structures, indicating their long-term stability in water environment.