Stretchable Multilayer Printed Circuit Boards: Fabrication, Surface Mount Challenge, Fundamental Research, and Applications

• Applicants: Professor Dr. Matthias Hein; Professor Dr. Heiko Jacobs, since 5/2021
• Subject Area: Microsystems ; Electronic Semiconductors, Components and Circuits, Integrated Systems, Sensor Technology, Theoretical Electrical Engineering ; Mechanical Properties of Metallic Materials and their Microstructural Origins
• Term: from 2018 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 407407910

• Final Report Year: 2025

Final Report Abstract

The project explored fundamental research to enable a stretchable and deformable printed circuit board technology. The general goal of this project is to enable the realization of reliable electronic structures that can be deformed to take on new three-dimensional shapes, different from conventional printed circuit board technology. We have explored the stretchability in this project from the fundamental as well as from the application aspect. We discovered a stressadaptive meander that can extend up to 320% of its initial length by altering the stress distribution and reducing the number of twists by experimenting with various manufacturing techniques and researching the failure causes. To attain the specific goals of this project we have also used our expertise in fluidic self-assembly and worked on the fundamental aspects of solder bumps to make them suitable for stretchable electronics as well as on the transport mechanism of the chips on top of the substrates. With the help of these fundamental understandings, we were able to do applications such as stretchable touchpads and deformable LED active-matrix arrays.

Publications

• Stress-adaptive meander track for stretchable electronics. Flexible and Printed Electronics, 3(3), 032001.
  Biswas, Shantonu; Reiprich, Johannes; Pezoldt, Joerg; Hein, Matthias; Stauden, Thomas & Jacobs, Heiko O.
  
• Fluidic Self-Assembly on Electroplated Multilayer Solder Bumps with Tailored Transformation Imprinted Melting Points. Scientific Reports, 9(1).
  Kaltwasser, Mahsa; Schmidt, Udo; Lösing, Lars; Biswas, Shantonu; Stauden, Thomas; Bund, Andreas & Jacobs, Heiko O.
  
• Integrated multilayer stretchable printed circuit boards paving the way for deformable active matrix. Nature Communications, 10(1).
  Biswas, Shantonu; Schoeberl, Andreas; Hao, Yufei; Reiprich, Johannes; Stauden, Thomas; Pezoldt, Joerg & Jacobs, Heiko O.
  
• Metamorphic Stretchable Touchpad. Advanced Materials Technologies, 4(4).
  Biswas, Shantonu; Reiprich, Johannes; Pezoldt, Joerg; Stauden, Thomas & Jacobs, Heiko O.
  
• "RF properties of stretchable transmis-sion line structures" German Microwave Conference (GeMiC), Cottbus, 2020
  U. Stehr, L. F. Centeno, Y. Ni, H. O. Jacobs & M. A. Hein
  
• Electrical lengths and phase constants of stretchable coplanar transmission lines at GHz frequencies. Flexible and Printed Electronics, 9(1), 015005.
  Pikushina, Alena; Centeno, Luis Fernando; Stehr, Uwe; Jacobs, Heiko & Hein, Matthias
  
• Patterned Liquid Micro Rails for the Transport of Micrometer Sized Chips. Advanced Materials Technologies, 9(17).
  Moreira, Pedro H. O.; Soydan, Alper K.; Reiprich, Johannes; Isaac, Nishchay A.; Aliabadian, Bardia; Vernizzi, Guilherme J. & Jacobs, Heiko O.
  
• Stretchable Printed Circuit Board Meets Stretchable Light Emitting Gallium Nitride. Journal of Engineering and Applied Sciences Technology, 7(2), 1.
  Mukherjee, Arka; Gohar, Ahmed Hassan; Centeno, Luis F.; Schlag, Leslie; A. Isaac, Nishchay; Soyda, Alper K.; Moreir, Pedro H. O.; Pezoldt, Jörg & Jacobs, Heiko O.