Lifetime models for printed 3D HF structures

• Applicant: Dr. Sina Martin
• Subject Area: Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology ; Production Systems, Operations Management, Quality Management and Factory Planning
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 528402728

Reliability analysis is of great importance to ensure the functionality of an MID assembly over the longest possible service life. Optical testing methods enable non-contact and non-destructive recording of measured values and, in the case of MID components, can detect in particular the distortion of the circuit carrier after a thermal process, the roughness of functional surfaces and metallization as well as damage to the conductor tracks. Possible optical methods include X-ray analysis and computer tomography as well as various microscopic methods such as scanning electron microscopy (SEM). In addition, destructive testing methods are used to determine the adhesive strength of the metallic structures. The electrode structures investigated in the joint project show clear structural differences to conventional conductor tracks. The test methods must be adapted for the printed and sintered inks based on micro- and nanometer-sized particles and wires, as these are also very brittle and thin. Therefore, well-founded criteria for the required adhesive strengths must be developed and suitable methods for the HF characterization of the printed conductor structures must be designed, mapped and analyzed under ageing conditions. The aim of the sub-project is to analyze the service life of printed 3D RF components under specific load collectives in order to be able to predict and optimize the reliability of electrically functionalized material combinations. To this end, reliability models adapted to the novel 3D RF components are being designed and suitable functional and long-term tests for their evaluation are being developed and carried out. The sub-project will therefore test the research hypothesis that the service life of printed 3D RF components can be predicted by a clever combination of both physical and simulative adhesion strength tests and RF functional tests as well as suitable statistical service life modelling. To this end, the results of the previous sub-projects on material, process and modelling/simulation research are to be integrated in order to map the influencing variables of the entire process chain on reliability in a virtual model. Both the adhesive strength and the HF properties (frequency-dependent transmission and reflection behavior) are to be assumed as a function of the dielectric material and its roughness, the ink composition and percolation density, the component dimensions, the sintering profile and the 3D substrate geometry.

• DFG Programme: Research Units
• Subproject of: FOR 5727: 3D functionalization for radio frequency applications
• Co-Investigator: Professor Dr.-Ing. Jörg Ernst Franke