Validation of material electrical properties between the true package and ideal modeling

The tolerance of dielectric constant between raw material before the substrate production and real sample after the process variation is the kernel of this project. In the past, the electrical data sheet of dielectric material always comes from the suppliers. However, material suppliers do not consider the effect of substrate manufacture but only implement the measurement through raw materials. Therefore, the strip line test vehicle is designed for Dk extraction to avoid the effect caused by other materials. In addition to strip line test patterns, the extraction method is the key in this project. T-resonator is designed and produced for dielectric constant extractions. The dielectric constants that are extracted by real sample become lower than raw prepreg, and the difference in impedance simulation reaches 6.7ohm. This has been already over SPEC ±1ohm ~ ±2ohm. Therefore, Dk extraction of real samples is imperative.