Inline quality control system for functional conductive 3D printing (PROPRIIS)

产品定制化和生命周期缩短的全球趋势对制造业提出了新的挑战。为了保证所查询的定制功能，增加系统的自主性，集成的传感器和执行器的数量不断增加。这增加了对柔性生产线的需求，而组件和连接器的自适应集成的问题仍然没有解决。汽车、航空航天、医疗技术和家庭部门是面临上述挑战的行业的主要例子。数字按需滴印，如喷墨或喷墨点胶，是应对这些挑战的可能解决方案之一。这些技术通过将功能油墨或浆料直接打印到各种复杂形状的部件上，提供印刷电路板、传感器、天线、加热结构或致动器的灵活集成和应用。这是为部件配备传感器和导电功能结构而不需要组装工作的先决条件。传统的按需滴制生产工艺由印刷工艺和印刷结构的热后处理组成。在这些技术阶段，印刷和后处理过程出现不准确，因此按需滴印不能提供稳定的印刷结构的再现性和质量，这是限制此类技术应用的主要原因之一。为了自动检测印刷和后处理过程中的缺陷率(工业4.0的概念)，作者建议开发一种基于电感阻抗光谱、激光几何测量系统和高温测量信号融合的在线测量系统，用于微小印刷结构的质量控制。所选择的非破坏性方法将提供沿打印路径的每个坐标中的几何和电学数据。为了获得正确的电学数据，必须对温度变化和涡流传感器的提离的影响进行补偿。该项目的第一个挑战是开发和生产一种高频涡流传感器，对潮湿状态下的微小印刷结构敏感。激光系统和高温计将从市场上现有的系统中选择。第二个挑战是创建一个经验模型来控制导电路径的质量，该模型融合了几何和电信号数据。该模型确定印刷结构在沿途每个坐标下的形态和实际电导率(补偿提离和温度影响)，以估计是否发生后处理的形态缺陷或不足。所开发的系统具有可转移性，可用于使用不同导电浆料的各种印刷技术所应用的路径或图案的质量保证。

The global trends of product customization and shorter life cycles present new challenges to the manufacturing industry. In order to guarantee the inquired customized functionality and to increase the autonomy of systems, the number of integrated sensors and actuators is constantly growing. This increases the demand for flexible production lines, while the problem of an adaptive integration of components and connectors remains unsolved. The automotive, aerospace, medical technology and household sectors are main examples of industries facing the challenges mentioned above. Digital drop-on-demand printing, such as ink-jet or jet-dispensing, is one of the possible solutions to these challenges. These technologies offer flexible integration and application of printed circuit boards, sensors, antennas, heating structures or actuators by printing functional inks or pastes directly onto the various complex-shaped components. This is a prerequisite for equipping parts with sensors and conductive functional structures without the need for assembly work. A conventional drop-on-demand production process consists of the printing process and the thermal post-treatment of the printed structures. During these technological stages inaccuracies of the printing and post-treatment processes occur, therefore drop-on-demand printing does not provide stable reproducibility and quality of the printed structures, which is one of the main reasons of limited application of such technologies. In order to automatically detect the rate of defects (with the concept of Industry 4.0), which occur during the printing and post-treatment process, the authors suggest to develop an inline measuring system, for quality control of tiny printed structures, based on the signals fusion of inductive impedance spectroscopy, laser geometry measurement system and pyrometry. The chosen non-destructive methods will provide geometrical and electrical data in each coordinate along the printed path. To achieve correct electrical data the influences of temperature variation and the lift-off of the eddy current sensor have to be compensated. The first challenge of the project is to develop and produce a high frequency eddy current sensor, sensitive to the tiny printed structures in a wet state. The laser system and pyrometer will be chosen from the available systems on the market. The second challenge is to create an empirical model for quality control of the conductive path, which fuses the geometrical and electrical signal data. The model determines the morphology and real conductivity (compensating lift-off and temperature influence) of the printed structure in each coordinate along the path in order to estimate if any morphological defect or deficiency of the post-treatment happened. The developed system is transferable and can be used for quality assurance of paths or patterns, applied by various printing techniques, which use of different conductive pastes.