The purpose of the experiment was to indicate which element of the production process of flexible printed circuit boards is optimal in terms of the reliability of final products. According to the Taguchi method, in the experiment, five factors with two levels each were chosen for the subsequent analysis. These included the number of conductive layers, the thickness of the laminate layer, the type of the laminate, the diameter of the plated holes, and the current density in the galvanic bath. The reliability of the PCBs in the produced variations was verified using the Interconnect Stress Test environmental test. The qualitatively best variant of the board construction was indicated using the signal-to-noise ratio and the analysis of variance method for each factor. The factors determined to be the most important in terms of reliability were the number of conductive layers and the current density in the galvanic bath. The optimal variant of the board construction was two conductive layers on a polyimide laminate, where the laminate layer was 100 μm thick, the hole diameter was equal to 0.4 mm, and current density was 2 A/dm² in the galvanic bath. Therefore, the plated experiment indicated the factors needed to obtain a high-quality product with a low failure rate.

The paper concerns the development of a technology for manufacturing printed circuits with metalized blind holes in the Stacked-Via and Staggered-Via techniques. The diameter of the holes were $70 \mu \mathrm{m}$ and $130 \mu \mathrm{m}$. The use of metalized blind holes, so called microvias, in multilayer printed circuit boards allows for an increase in the density of connections, and thus allows for an increase in the speed of data transfer and miniaturization of electronic devices. The blind holes in the laminate were drilled using UV laser and then metalized in galvanic bath. Optimal parameters of the laser drilling tool were chosen based on the result of Taguchi method. Multilayer printed circuits made using the sequential build-up technique are also manufactured with chosen approach.

The purpose of the experiment was to indicate which element of the production process of flexible Printed Circuit Board is optimum in terms of the reliability of final products. According to the Taguchi method in the experiment five factors, two levels each, were chosen for the subsequent analysis. These include: the number of conductive layers, the thickness of the laminate layer, type of the laminate, the diameter of the plated holes, the current density in the galvanic bath. The reliability of the PCBs in produced variations was verified using the Interconnect Stress Test environmental test. The qualitatively best variant of the board construction was indicated using the signal-to-noise ratio and analysis of variance method for each factor. The factors that turned out to be the most important in terms of reliability are the number of conductive layers and the current density in the galvanic bath. The optimal variant of the board construction is two conductive layers, on a polyimide laminate, where laminate layer is 100 μm thick, hole diameter equal to 0.4 mm and current density of 2 A/dm2 in the galvanic bath. Therefore the plated experiment indicated factors needed to obtain a high-quality product with a low failure rate.