2026, Vol. 6, Issue 1, Part A
Electromagnetic interference shielding effectiveness of conductive coatings on plastic enclosures
Author(s): Thabo Molefe
Abstract: Plastic enclosures offer manufacturing advantages over metal housings but lack inherent electromagnetic interference shielding capability required for regulatory compliance. This research evaluated six categories of conductive coatings applied to acrylonitrile butadiene styrene (ABS) enclosures, measuring shielding effectiveness across the frequency range from 30 MHz to 6 GHz relevant to commercial EMC standards. Coating types included nickel-based conductive spray, copper conductive spray, silver-filled conductive paint, carbon-loaded conductive paint, nickel-acrylic composite, and copper-graphite hybrid formulations. Specimens were prepared using spray application with controlled thickness ranging from 10 μm to 50 μm, followed by shielding effectiveness measurement per IEEE 299 methodology using a reverberation chamber technique. Silver conductive paint achieved the highest shielding effectiveness at 55.2±2.8 dB at 100 MHz with 25 μm coating thickness, decreasing to 48.3±3.1 dB at 3 GHz. Copper spray provided comparable performance at 48.7±2.4 dB and 40.1±2.9 dB respectively, at 60% lower material cost. Carbon-based coatings achieved 28.4±2.1 dB maximum shielding, insufficient for commercial EMC requirements but adequate for consumer electronics applications. Coating thickness exhibited approximately linear relationship with shielding effectiveness below 30 μm, with diminishing returns above this threshold. Surface resistivity correlated strongly with shielding performance (R² = 0.94), enabling rapid screening of coating quality without full electromagnetic characterization. These findings establish quantitative selection criteria for conductive coatings based on EMC compliance requirements, operating frequency, and cost constraints.
DOI: 10.22271/27084493.2026.v6.i1a.83
Pages: 38-44 | Views: 35 | Downloads: 16
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How to cite this article:
Thabo Molefe. Electromagnetic interference shielding effectiveness of conductive coatings on plastic enclosures. Int J Electron Microcircuits 2026;6(1):38-44. DOI: 10.22271/27084493.2026.v6.i1a.83
