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Introduction. When manufacturing printed circuit boards (PCBs), including their prototypes, the proper alignment of PCB layers is mandatory. While the causes and preventive measures against misalignment in PCBs manufactured using conventional technologies are known, research into alignment errors in 3D-printed PCBs is still ongoing. Another task regarding 3D printing, which is related to topological accuracy (alignment errors in particular), consists in ensuring the opportunity to remove the printed part of the product in order to perform operations thereon, such as embedding components, followed by its return and continuation of the printing process.Aim. Numerical estimation and analysis of the causes of layer-to-layer alignment errors in PCBs manufactured using 3D printing.Materials and methods. The research was conducted using the following materials and equipment: Polyethyleentereftalaatglycol (PETG); an Ultimaker Cura slicer; an Ender 3 S13D printer; a brass nozzle with a diameter of 0.3 mm. The study was conducted using the facilities of the Additive Technologies Center, Bauman Moscow State Technical University. Interlayer alignment errors are estimated by microsection analysis and X-ray inspection, as well as using the misalignment decomposition method described by Yu.B. Tsvetkov for electronics.Results. The possibility of manufacturing PCB prototypes with three conductive layers is demonstrated, including a method for removing the printed part of the product and its further return in the printing process using printed pins. Large-scale distortions were found to make the largest contribution to the alignment error: on average, approximately 150 gm for each layer when compared to its 3D model and approximately 60 gm when comparing the topology of the top layer with the bottom layer. These values exceed the common misalignment value of 50 gm for the pin lamination process. This substantiates the need to control and minimize temperature effects, e.g., using 3D printers with a thermostatically-controlled chamber.Conclusion. The conducted analysis of possible causes of misalignment emergence determines the significance of temperature gradients that occur during 3D printing. The proposed manufacturing method allows the printed part of the product to be removed and further returned into the printing process, which can be used to produce PCB prototypes with three conductive layers.

Introduction. A review of foreign publications on 3D printing methods shows the possibility of their application for the manufacture of printed circuit boards (PCBs), while demonstrating the growth of interest in this field. One of the available methods is fused deposition modeling, which can be used to form substrates with channels for traces. At present, the minimum channel width comprises 100 µm, which corresponds to the 5th class of PCB accuracy. However, there is no data on how to obtain such dimensions or on the magnitude of their deviation from the given nominal values.Aim. To determine the influence of such factors as nozzle diameter and the number of contours on the dimensional characteristics of PCBs (linear dimensions; trace channel width; trace spacing; via diameters).Materials and methods. To obtain linear models, a full factorial experiment was carried out. The influence of the following materials was evaluated – polylactide (PLA), acrylonitrile butadiene styrene (ABS) and glass-filled ABS; slicers – Ultimaker Cura and PrusaSlicer; 3D printers – Picaso 3D Designer Classic 2016 and Hercules Strong 2017; brass nozzle with diameters ∅0.2 and ∅0.4 mm. The possibility of using brass nozzles coated with chemical nickel for printing with glass-filled filaments was considered. The study was conducted using the facilities of the "Center for Additive Technologies" of Bauman Moscow State Technical University.Results. The possibility of manufacturing PCBs up to the 2nd and 3rd accuracy classes using nozzles with a diameter of ∅0.4 and ∅0.2 mm, respectively, was shown. It was found that galvanic deposition of chemical nickel on a ∅0.2 mm brass nozzle makes it possible to increase the PCB wearability when printing with glass-filled filaments. Recommendations are proposed for selecting an optimal combination of nozzle diameter and the number of contours.Conclusion. The conducted analysis of mathematical models shows the significance of such parameters as nozzle diameter and the number of contours. The results can be used when creating new PCB layouts