Three dimensional molded interconnect devices (3D-MID) are 3D shaped thermoplastic substrates, combining mechanical, electronic and optical functionalities in one single assembly. One especially challenging process step during their manufacturing is the application of the conduction pattern layout on the complex three dimensional substrates. Therefore innovative printing and structuring technologies can be used. Essential for a good process result is an exact positioning or movement of the substrate relative to the process tool. For this purpose the great flexibility of movement of buckling arm robots can be used. A main drawback of conventional industrial robot is their relative low accuracy, which doesn’t meet the high requirements of miniaturized and complex 3D-MID products. This subject matter is addressed in the research project “Accuracy optimization of Industrial robots in the area of structuring and metallization of three dimensional molded interconnect devices”, in which a system for accurate robot based positioning and movement in course of the generation of the conduction patter layout by metallization and structuring processes should be developed.
Therefore a high speed camera-system is used for determining the actual position and movement of the substrate during the process. The actual movement of the substrate is subsequently compared with information regarding the target movement and succeeding correction values are calculated. By integrating these values in the robot control in course of the process, a significant accuracy improvement can be achieved. Additional to a highly efficient and accurate method for image data processing an accordingly efficient correction value determination and robot closed loop control is of significant importance. Furthermore, in course of the project a highly accurate 3D surface scanning device is used for determining positioning errors of the substrate in the gripper system and process space. By using the 3D-data of this system, it might be as well possible, to determine deviations of the real part compared to the optimal work piece shape and derive process parameter adapted to the individual part.
Developed exemplary according to the high requirements of the 3D-MID technology, the project results should provide an extensive methodology for accuracy improvement of industrial robots during different applications.