Alignment Error Estimation of the Conductive Pattern of 3D-Printed Circuit Boards

Abstract

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.