Issue link: https://iconnect007.uberflip.com/i/834021
16 The PCB Magazine • June 2017 by Jesse Ward COMPUNETICS, INC. Introduction Compunetics has been operating in the em- bedded components market for more than 20 years. Initially driven by their parent company's need for high layer-count, high-density embed- ded capacitance cards for their OEM product of- ferings, technology and processes were devel- oped which are mature and reliable. Embedded technology is integrated into PCBs using con- ventional processing techniques; the capaci- tive layers are drop-in replacements in the ex- isting PCB stack. However, special processing is required to properly transport the extreme- ly thin cores associated with embedded capaci- tance layers (three to 25 microns thick). Embedded capacitors rely on utilization of planar copper-clad, thin-core laminate (Figure 1). These laminates replace decoupling capaci- tors which are normally mounted next to an IC. The IC is routed directly to the capacitive layer using vias. The laminates are drop-in replace- ments that use the existing PCB stack-up. Var- ious dielectrics and core thicknesses are avail- able. For example, DuPont HK04 material uti- lizes a 1-mil copper-clad polyimide core which functions as an ideal capacitor (Figure 2). Each clad layer of the core acts as opposing capacitor A Brief Tutorial on Embedded Capacitors FEATURE Figure 1: Basic construction of a capacitance layer: thin core (orange) and etched copper cladding (red). Source: Dupont. Figure 2: The technology addresses many issues with PCB design and power delivery at the same or lower cost, plus it's more reliable. Source: Oak-Mitsui