A Brief Tutorial on Embedded Capacitors

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Introduction

Compunetics has been operating in the embedded components market for more than 20 years. Initially driven by their parent company's need for high layer-count, high-density embedded capacitance cards for their OEM product offerings, technology and processes were developed which are mature and reliable. Embedded technology is integrated into PCBs using conventional processing techniques; the capacitive layers are drop-in replacements in the existing PCB stack. However, special processing is required to properly transport the extremely thin cores associated with embedded capacitance layers (three to 25 microns thick).

Embedded capacitors rely on utilization of planar copper-clad, thin-core laminate (Figure 1). These laminates replace decoupling capacitors which are normally mounted next to an IC. The IC is routed directly to the capacitive layer using vias. The laminates are drop-in replacements that use the existing PCB stack-up. Various dielectrics and core thicknesses are available. For example, DuPont HK04 material utilizes a 1-mil copper-clad polyimide core which functions as an ideal capacitor (Figure 2).

To read the full version of this article which appeared in the June 2017 issue of The PCB Magazine.