Design and Performance of Additively Manufactured In-Circuit Board Planar Capacitors

This article discusses the design and performance of planar capacitors built as pairs of conductive plates by additive manufacturing as part of an electronic circuit board. This article covers several geometries and layers of parallel plates that allow for different capacitance values, from a few picofarads (pF) to several nanofarads (nF). The dc, ac, and radio frequency (RF) characterization demonstrated superior performance compared to off-the-shelve surface mount device (SMD) capacitors up to 20 GHz. The additively manufactured capacitors exhibit breakdown voltages in excess of 1 kV and subpicoampere leakage currents, while the change in RF impedance changes, as a function of frequency, is a factor of $3\times $ smaller than SMD capacitors.