Dr. Anna Endrikat and Lara Eggert, Department of Electrochemistry and Electroplating at TU Ilmenau, Interview: Robert Piterek
Dr. Endrikat, Ms. Eggert, you are currently carrying out an exciting ZIM project at TU Ilmenau, please briefly describe the project and its objective!
We are currently working on the ZIM project "Additive manufacturing of printed circuit boards with galvanic coating" with two industrial partners, the companies 4D Concepts GmbH and Gigler Elektronik GmbH. The use of two different plastics in FDM printing (Fused Deposition Modeling) creates the conditions for selective metallization of the conductor path structures. As part of the project, the company 4D Concepts GmbH is working on the FDM printing of circuit carriers with two different plastic filaments. The Department of Electrochemistry and Electroplating at the TU Ilmenau is investigating the selective chemical metallization of these printed components. The company Gigler Elektronik GmbH is testing the coated 3D components with regard to suitable assembly processes.
What is the particular challenge in electroplating 3D-printed substrates?
There are several challenges when metallizing 3D-printed components. First of all, suitable plastic filaments must be selected. When making this selection, the flow properties are particularly important for FDM printing. In order to ensure optimum bonding or adhesion of both plastics in the printed component, it is important to match the printing parameters of both filaments to each other. In addition to the flow properties, low water absorption and good chemical resistance must be taken into account for chemical metallization. Another challenge is the surface roughness of printed plastics. Compared to injection moulding, printed components have a higher roughness, so pre-treatment and activation must be adapted for chemical metallization. In summary, the challenges for the metallization of 3D-printed components are an interplay between plastic, printing process, pre-treatment and metallization.
And how do you selectively metallize?
The metallization process involves chemical metallization. Plastic electroplating takes place in the conventional way with a few adjustments. Therefore, theoretically, a range of metals such as nickel, copper and tin are available. The entire metallization process must be adapted to the challenges of 3D-printed FDM components. The selection of plastic filaments is important to ensure selective metallization. The challenge here is clearly that in a metallization process, one plastic is coated while the other must not have any metallization.
What advantages does this selective coating of PCBs offer users and what possible applications are there?
Our process has clear advantages over conventional PCB production and MID technology (Molded Interconnect Devices) using laser structuring. FDM printing is an inexpensive process and very flexible in its application. Thanks to the greater product flexibility compared to injection molding processes and the lower investment costs (for laser technology, among other things), components can be produced for customers individually, quickly and cost-effectively, even in small quantities. As a result, the process is very well suited to the production of prototypes. Although our project currently only relates to circuit carriers, our process can also be used in other branches of industry. Thanks to the flexibility of 3D printing and selective coating, the industrial application possibilities are many and varied.
INFO
Dr. Anna Endrikat and Lara Eggert are research assistants in the Department of Electrochemistry and Electroplating at TU Ilmenau.
Lara Eggert is currently working on her doctorate under Prof. Andreas Bund, who has been head of the department for 12 years. Research projects at the Thuringian engineering school often involve close cooperation with industry, as in this case.
In addition, emphasis is placed on application-oriented research.
