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The demand for thinner and more uniform conformal coatings in aerospace electronics has increased with the miniaturization of RF assemblies. In such applications, even minor variations in coating thickness can degrade dielectric properties, compromise RF signal integrity, and reduce long-term environmental reliability. This study presents the process development and statistical capability analysis of nano thin film acrylic conformal coating (CytoPel) applied to aerospace printed circuit assemblies using an automated selective-spray system. A Design of Experiments (DOE) was conducted to achieve two target thicknesses-<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3 \mu \mathrm{m} \pm 0.5 \mu \mathrm{m}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1 \mu \mathrm{m} \pm 0.5 \mu \mathrm{m}$</tex>-by optimizing key dispense parameters, including valve opening, atomizing pressure, nozzle-to-board height, coating head speed, and pass overlap strategy. Each parameter was varied systematically to evaluate its effect on coating thickness, uniformity, and process repeatability. Coating thickness was measured on metal coupons using an eddy-current gauge after 1-hour cure at 80 °C. The optimized process achieved a mean thickness of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.00 \mu \mathrm{m}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$1.00 \mu \mathrm{m}$</tex> with corresponding Cpk values of 2.08 and 1.44, demonstrating high process capability and repeatability. Thickness variation across multiple coupons remained within specified tolerance limits, confirming the robustness of the DOE-derived parameters. Environmental validation, including salt-fog exposure and thermal cycling, demonstrated no degradation of coating integrity. Functional testing confirmed that RF performance of the assemblies was maintained, indicating that the ultra-thin coating did not adversely affect electrical or dielectric characteristics. This work establishes a validated process window and a scalable framework for qualifying thin-film nano conformal coatings in RF-sensitive aerospace assemblies. By systematically controlling dispense parameters and leveraging statistical analysis, the process ensures consistent coating thickness and uniformity while meeting stringent aerospace quality standards. Overall, this work demonstrates that ultra-thin nano-engineered conformal coatings can be reliably applied using an automated selective-spray system, and that process optimization combined with capability analysis provides a robust pathway for qualifying coatings in high-performance aerospace electronics. The approach not only supports current assembly requirements but also establishes a foundation for continuous improvement and broader application of thin-film coatings in aerospace and other high-reliability electronic systems.