With the demand of small and high performance electronic products, the number of circuits in small packages is continuously increasing, and the wiring in PCBs is getting shorter to reduce the losses at high frequency operations. This trend encourages the development of embedded PCBs that includes passive components inside the insulation layer. We apply the space charge measurement technique to investigate the process of ion migration, and contribute to establish reliability test procesure of PCB insulations.
The operating frequency of electronic circuits has increased rapidly. The performance, as well as electromagnetic compatibility (EMC) characteristics, of PCBs is influenced by the dielectric properties of the insulation layers of PCBs. The complex permittivities of insulating materials have been measured by the capacitance method, and most of the values provided by manufacturers are those obtained at 1 MHz, at room temperature and at uncontrolled humidity. We investigate high frequency characteristics of PCB insulation, and the effect of temperature and humidity.
