In Case You Missed It

Flex Circuits

“Facile Preparation of High-Precision Flexible Circuits through Combining Inkjet Printing and Template Plating”

Authors: Qing Li, et al.

Abstract: Driven by the rapid evolution of electronic devices toward multifunctionality and portability, circuits fabricated on flexible substrates require increasingly higher manufacturing precision to support the integration of high-density electronic components. In this work, a facile strategy combining inkjet printing and template plating was proposed to fabricate high-precision flexible circuits. An adhesive layer was first introduced onto the polyimide substrate to enhance interfacial adhesion and substrate compatibility, followed by inkjet printing of a resin solution to form circuit templates. The uniform template with an average line width of 58.5μm was obtained by optimizing the printing parameters. The printed template was chemically modified via alkali treatment and Ag activation, which generates catalytically active sites for selective electroless Cu plating. The uniform Cu circuits with an average width of 63.2μm were obtained, exhibiting low resistivity of 8.45μΩ cm, strong adhesion strength of 5B, and excellent fatigue resistance under cyclic bending. Moreover, the Sn circuit was electroplated based on the Cu circuit template. The precision consistency of the Sn circuits was confirmed by electrical fusing tests according to the corresponding national standard (GB/T 9364.4-2016). The Sn circuit also exhibited strong thermal stability during reflow cycles at 220°C. These results demonstrate the enormous application potential of the proposed strategy for the additive manufacturing of high-precision flexible circuits. (Journal of Materials Science: Materials in Electronics, vol. 37, number 1900, Aug. 26, 2026, https://link.springer.com/article/10.1007/s10854-026-18254-0)

Inspection

“Vision-Based PCB Defect Detection Using YOLOv5 and MobileNetV2 with Grad-CAM”

Authors: Selva Kumar Chandrasekar, et al.

Abstract: Printed circuit board (PCB) defects such as mouse bites and missing holes significantly impact the reliability of electronic devices. Traditional PCB defect inspection technique relies on worker experience and unreliable in accuracy and scalability. This paper presents a hybrid vision-based approach that integrates YOLOv5 for defect detection, MobileNetV2 for defect verifying and reducing false positives, and Grad-CAM for generating visual heatmaps that highlight critical defect regions. YOLOv5 efficiently identifies potential defect locations, while MobileNetV2 acts as a lightweight classifier to ensure only true defects are identified. Grad-CAM provides interpretability by visually explaining the model’s decisions, aiding quality control operators. Performance metrics including precision, recall, and F1-score are employed to evaluate detection performance comprehensively. Additionally, a severity index is computed based on the nature of the defects according to their effect of the PCB’s function. The proposed method’s advantage in detection accuracy, false positive minimization and effective interpretability is demonstrated. This work improves vision-based PCB defect inspection systems through a reliable and interpretable 3-level machine vision method for PCB defect detection. (Proceedings of International Conference on Computational Intelligence, Aug. 2, 2026, https://link.springer.com/chapter/10.1007/978-3-032-31523-6_15)

Materials

“Sustainable Flame-Retardant Self-Reinforced Composites: The Role of mPAO in Fabrication and Recycling”

Authors: Dr. Jin Chul Kim, Dr. Ji-Eun Jeong and Dr. Young-Jae Jin 

Abstract: The development of recyclable, high-performance polymer composites are essential to address the challenges of environmental sustainability and carbon neutrality. This study explores the multifunctional role of metallocene poly(α-olefin) (mPAO) in enhancing the rheological, thermal, mechanical, and recycling properties of high-density polyethylene (HDPE)-based self-reinforced composites (SRCs). An ionic phosphorus-based flame retardant (ADK) was incorporated for its environmental compliance and facile removability during recycling. The addition of mPAO not only facilitated a more homogeneous dispersion of ADK within the HDPE matrix but also tailored the melt rheology of HDPE films, improving processability and fiber–matrix interfacial adhesion. Recycling was achieved by sequentially removing ADK using aqueous sodium hydroxide and extracting residual mPAO with hexane, enabling high-purity HDPE recovery. The optimized S-PE-mPAO5-ADK40 composition delivered outstanding mechanical strength and achieved a UL-94 V-0 flame-retardant rating. These findings highlight the potential of mPAO as a multifunctional additive for fabricating sustainable, high-performance, and fully recyclable polymer composites for industrial applications. (Composites Part B: Engineering, vol. 312, Mar. 1, 2026, https://www.sciencedirect.com/science/article/pii/S1359836825012399?via%3Dihub)

Thermal Managament

“Thermal Management in Electronics: From Conventional Cooling to Hybrid Innovations”

Authors: Bijaya Raj Karki and Aayush Luitel

Abstract: The relentless miniaturization of electronic devices and escalating heat fluxes in data centers, electric vehicles, and aerospace platforms, projected to exceed 1000W/cm² in next-generation chips, have intensified the demand for advanced thermal management. This review systematically surveys electronic cooling progress across a normalized set of metrics: junction-to-coolant thermal resistance, heat flux, pressure drop, and power usage effectiveness (PUE). Conventional strategies including natural and forced-air convection, heat sinks, liquid cold plates, phase-change systems, and thermoelectric coolers are evaluated for their capabilities, limitations, and applicability across heat flux regimes. Emerging approaches such as two-phase microchannel cooling, single-phase and two-phase immersion cooling, jet impingement, spray, and electrohydrodynamic techniques are discussed, with demonstrated performance up to 2000W/cm² and PUE values as low as 1.02. Material innovations including graphene spreaders, SiC microchannel substrates and nano-enhanced phase change material (PCMs), alongside computational tools such as topology optimization and machine learning (ML)-augmented computational fluid dynamics (CFD), are identified as enablers of step-change performance gains. Cost, carbon footprint and regulatory considerations, including post-per- and polyfluoroalkyl substances (PFAS) dielectric fluid requirements, are integrated throughout. Open challenges in two-phase flow instability, lifecycle assessment standardization, adaptive workload-driven control, and long-term hybrid system reliability define the critical research agenda bridging laboratory demonstrations and industrial deployment. (Journal of Electronic Packaging, June 2026, https://asmedigitalcollection.asme.org/electronicpackaging/article-abstract/148/2/020905/1233293/Thermal-Management-in-Electronics-From)End of article content