In Case You Missed It
Conductive Adhesives
“An Electrically Conducting Water-based Reversible Adhesive”
Authors: Bassam A. Aljohani, Ama B. Asiedu-Asante, Adriana Sierra-Romero, Katarina Novakovic, Volker Pickert and Mark Geoghegan
Abstract: An electrically conducting reversible adhesive with conductivity up to 2.9 × 105 S m−1 and lap shear strength of up to 1.5MPa is presented. The reversibility of the glue enables debonding of surfaces on exposure to alkaline media. The adhesive comprises polyelectrolyte-stabilized nanoparticles synthesized by emulsion polymerization and silver nanoparticles as conductive filler. The conductivity of these formulations is comparable to, or exceeds, that of commercially available conductive adhesives, while their mechanical performance is consistent with typical water-based adhesive systems. Adhesion is reversed by immersing the bonded joints at pH 14. By heating to 85°C and stirring the solution (500rpm), the debonding time can be reduced to ∼30 min or less. Separation can also be achieved at 85°C at pH 7. Short debonding times can also be achieved at room temperature by using acetone, a recognized green solvent. This electronically conducting reversible adhesive, therefore, presents a great opportunity to improve the reuse or recycling of electronic components. (Advanced Electronic Materials, May 14, 2026; https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500617)
Electrothermal Modeling
“Simulation of Electrothermal Transient Responses in Power PCB Modules Using Comsol, Spice, and Asonika-TM”
Authors: K. O. Petrosyants, I. A. Kharitonov and M. S. Tegin
Abstract: Large temperature jumps in the structures of power semiconductor devices when they are turned on and off significantly reduce the reliability of power circuits. The widely used electrothermal modeling approaches for thermal circuits have a number of disadvantages: the use of interconnected Spice simulators and the numerical 3-D thermal field modeling tool requires a detailed description of 3-D structures and significant computer time; the use of only Spice-like simulators of electrical circuits for mixed electrothermal modeling requires the creation of electrothermal models of power components and significant CPU time costs due to the large difference in the time constants of the electrical and thermal parts. In this study, an improved scheme for multilevel automated electrothermal modeling and simulation of power electronic components is proposed and implemented, using the Comsol software at the semiconductor device level, Spice simulation at the circuit level, and the Asonika-TM system at the printed circuit board (PCB) level. The developed additional software tools for implementing the proposed route are described, providing automation of power-calculation processes for components of power circuits, transferring the obtained values to a thermal simulation tool, and forming electrothermal models of the circuit components. The correctness of the proposed modeling scheme is confirmed by the results of thermal-imaging analysis using an IR camera. The effectiveness of the proposed methodology is demonstrated through the example of a real PCB design with high-power MOSFETs for controlling a power stepper motor. In the analyzed circuit, a possible thermal failure of the output DMOSFETs due to their overheating is revealed. To improve the conditions for reducing their temperature, it is proposed to use a larger electrode radiator with lower thermal resistance. (Russian Microelectronics, December 2025; https://doi.org/10.1134/S106373972570009X)
Flex Circuits
“Scalable Roll-to-Roll Approach for Encapsulating Long-Length Flexible Printed Circuit Boards”
Authors: Chan-Woo Lee, Eun-Ji Gwak, Doo-Sun Choi and Byoung-Youn Cho
Abstract: The encapsulation process in flexible printed circuit board (FPCB) manufacturing typically involves laminating a flexible copper-clad laminate (FCCL) with a coverlay film, using heat and pressure in methods such as hot press lamination. When they are applied to long-length FPCBs for electric vehicle applications, however, traditional hot press methods face challenges in scalability and productivity. To overcome these challenges, this study proposes a scalable roll-to-roll approach for encapsulating long-length FPCB. This approach enhances scalability to meet the requirement of long-lengthening continuously, but this can lead to incomplete filling in narrow circuit patterns due to insufficient flowability of the B-stage adhesive. To enhance flowability, a roll-to-roll system was developed that incorporates a rubber roll and a steel roll for the adhesive material. The effects of copper width dimensions and process parameters on encapsulation performance were investigated in the experimental analysis, based on rheological and thermomechanical characterizations of the B-stage adhesive. These results were quantified through image analysis and visualized using contour mapping to exhibit the influence of process parameters on the filling area. The reliability and durability of the developed approach were validated by analyzing adhesive properties and electrical performance. The developed roll-to-roll approach to the encapsulation process enables scalability while ensuring the durability and reliability of the long-length FPCB. (ACS Applied Materials & Interfaces, Aug. 21, 2025, vol. 17, no. 36; https://pubs.acs.org/doi/10.1021/acsami.5c09839)
Novel Substrates
“High-Density Papertronics via Laser-Written Hydrophilicity on Hydrophobic Parchment Paper”
Authors: Zahra Rafiee, Ruohan Zhang and Seokheun Choi
Abstract: High-resolution paper-based electronics are fundamentally limited by uncontrolled ink spreading within porous cellulose networks, which constrains device density and functional integration. Here, the authors introduce a laser-induced hydrophilic patterning strategy on commercially available hydrophobic parchment paper that fundamentally redefines the resolution, scalability, and design freedom of papertronics. Local laser modification converts selected regions into ink-guiding, hydrophilic microchannels, enabling deterministic confinement of functional materials without the need for wax, masks, or high-temperature processing. This strategy supports few-hundred-micrometer-scale patterning, achieving a >200% reduction in device footprint relative to wax-based approaches and offering a clear route toward further miniaturization via optical refinement. Using this platform, the authors realize fully printed resistors, low-loss interconnects, interdigitated capacitors, and integrated low- and high-pass RC filters within a single paper layer, exhibiting predictable, tunable electrical behavior consistent with circuit theory. Importantly, the predominantly cellulose-based substrate preserves biodegradability and disposability, while optional elastomeric encapsulation confers environmental robustness without compromising performance. By unifying high-resolution patterning, functional integration, and environmental compatibility, this work establishes laser-patterned parchment paper as a scalable and sustainable electronics platform, bridging the gap between laboratory papertronics and deployable electronic systems. (ACS Applied Materials & Interfaces, vol. 18, no. 16; https://pubs.acs.org/doi/10.1021/acsami.6c03065)End of article content