Alpha Environmental (United States)

The fabrication of a functional Printed Circuit Board (PCB) is a complex, multi-step process that plays a critical role in the modern electronics industry, an industry valued at $74 billion in 2024 and estimated to grow to $100 billion by 2029 (Prismark data). A key step in PCB manufacturing is primary metallization, specifically the process of making drilled holes conductive. Traditionally, this has been achieved using electroless copper deposition. However, direct metallization technologies based on carbon or graphite have existed as niche alternatives for over four decades, often limited by concerns regarding reliability and broader market acceptance.In recent years, advancements in colloidal chemistry and process engineering have significantly improved the stability, performance, and sustainability of carbon- and graphite-based direct metallization systems. These innovations include more consistent colloidal dispersions, enhanced wet etch techniques, and superior coating uniformity, all contributing to a substantial reduction in void formation. These improvements enable direct metallization to meet the stringent quality and environmental standards demanded by today’s High-Density Interconnect (HDI) and advanced packaging applications.This paper explores the evolution of colloid science in PCB manufacturing, detailing how next-generation carbon and graphite processes offer a more reliable and environmentally friendly alternative to traditional electroless copper. The result is a more viable metallization method better suited to meet the increasing performance demands of today’s and tomorrow’s electronic applications.

ABSTRACT The growing integration of larger Ball Grid Arrays (BGAs), ceramic packages, and Wafer-Level Chip Scale Packages (WLCSPs) into automotive and other harsh-environment electronic systems necessitates enhanced reliability in printed circuit board (PCB) assemblies. These demanding environments—characterized by elevated thermal loads, mechanical stresses such as vibration and shock, and stringent operational requirements—pose significant challenges to the structural integrity and performance of electronic components. As advanced packaging technologies continue to evolve and design tolerances become more stringent, the selection and qualification of reinforcement materials, including underfills and Edgebond adhesives, have become increasingly critical. To meet the elevated reliability standards required in these conditions, advanced reinforcement strategies are being adopted, including the use of high-reliability solder alloys, flowable underfills, and no-flow Edgebond materials. Flowable underfills provide mechanical stability by fully encapsulating the interstitial spaces beneath components, while Edgebond materials are applied along the periphery of packages to enhance edge support and streamline assembly processes. The optimal reinforcement approach is influenced by multiple factors, including device architecture, warpage behavior, I/O pitch, and production throughput constraints. This study presents a comparative analysis of high-reliability solder alloys in combination with underfill and Edgebond materials to enhance the mechanical and thermomechanical durability of BGAs and WLCSPs for use in automotive and other high-stress environments. The evaluation encompasses a range of package sizes, I/O pitches, and warpage profiles, subjected to two distinct thermal cycling regimes. Mechanical reliability is assessed through vibration and mechanical shock testing, while thermomechanical performance is evaluated via thermal cycling. The results highlight the efficacy of specific material combinations and reinforcement strategies in improving the structural robustness of advanced electronic packages. These findings contribute to the development of next-generation packaging solutions capable of withstanding the rigorous demands of high-reliability applications in the automotive and industrial sectors.

The recent regulation around PFAS has prompted many suppliers to rethink their offerings in terms of greener and sustainable solutions. In die attach, Quad Flat No lead (QFN) packages in large body format represent one of the steadiest growing types of chip carriers. Owing to their low profile, condensed form factor, high I/O and high thermal dissipation they are popular choices for chip set consolidation, miniaturization, and chips with high power density. There is demand for continued improvements in reliability of QFNs. Compatibility with flexible manufacturing and broad latitude performances are key areas that are critical for large body QFN type devices in Auto and RF markets.

Near-eutectic tin-bismuth alloy is a strong contender as the solder of choice for low-temperature electronic assembly applications. This paper will describe the recent significant developments by the iNEMI project team on the understanding of the electromigration behavior of Sn-Bi solder which has a unique physical metallurgy and electromigration behavior quite different for that of Sn-Ag-Cu (SAC) solder and other solders in common use today. The high rate of Bi electromigration and its high homologous temperature sets the near-eutectic Sn-Bi solder apart from the SAC and the Sn-Pb solders. The latter have lower homologous temperatures and have no one element dominating the electromigration phenomenon that can be readily tracked to monitor their electromigration behavior. In Sn-Bi alloys, the rates of Bi electromigration are clearly reflected in the rates of electrical resistance increase making it more convenient to use the fundamental physics-based electromigration equations rather than Black’s somewhat empirical equation that deals with the mean time to failure of solder joints. The high homologous temperature of Sn-Bi alloys makes in-situ study of electromigration in a scanning electron microscope more convenient, resulting in a much deeper understanding of the physical metallurgy and electromigration of the Sn-Bi alloys. For example, recent in-situ studies have shown that the root cause of decreasing solder electrical resistance in the early stage of electromigration, very evident at low temperatures and low current densities, is due to the microstructural coarsening of the alloy. When results are summarized on Arrhenius plots, the prediction of electromigration life under any given field condition becomes straightforward.

ABSTRACT Conventional electronics manufacturing and assembly typically involve extensive use of rigid FR4-based PCBs and flexible polyimide-based PCBs. Both rigid and flexible PCBs commonly utilize subtractive and etching processes for PCB fabrication, followed by standard SMT printing and assembly processes. As electronics integration becomes more ubiquitous, emerging manufacturing methods must be sustainable and utilize additive, greener processes. Additionally, there is a growing demand for next-generation 3D electronic shapes and PCBs compared to standard rigid 2D FR-4 PCBs. These next-gen electronics require lightweight, thinner form factors, robustness, and integration. To address these requirements for 3D and integrated electronics, various pathways and platforms are being currently explored. This paper focuses on the In-Mold Electronics (IME) approach, which facilitates the transition from subtractive to additively printed, robust, and 3D electronic structures. The paper delves into the key building blocks of In-Mold Electronics, including flexible hardcoated polymeric substrates, formable conductive silver inks, formable insulating/dielectric inks, and electrically conductive adhesives (ECAs). It also discusses various process considerations and requirements such as screen printing, thermal curing, thermoforming, and injection molding. Finally, the paper addresses some of the thermal and electrical reliability requirements for IME structures and covers the preliminary results of the IME structures. It concludes by demonstrating how IME can be utilized for sustainable and greener high-volume manufacturing, facilitating the fabrication of next-generation 3D electronics to meet emerging requirements.

ABSTRACTThis article compares the full installation and operational costs of a hydraulic containment (“pump‐and‐treat,” P&T) system with those of a hypothetical contemporary in situ colloidal activated carbon (CAC) barrier. Worked examples are provided using public domain data from the FT‐02 fire‐fighting training site on the former Wurtsmith Air Force Base in Oscoda, MI. The projected CAC costs are approximately a third of the P&T costs over projection periods of 15–100 years ($ 7.2 M vs. $ 19 M at 30 years; 38%). Hydraulic containment and CAC remediation systems prevent the spread of per‐ and polyfluoroalkyl substance (PFAS)‐contaminated groundwater. Hydraulic containment works by extracting contaminated groundwater, removing the contamination using activated carbon or other means, and re‐injecting the cleaned groundwater. The arrangement of extraction and injection wells and the related groundwater pumping rates create a hydraulic barrier that captures and contains the PFAS plume. In situ CAC barriers work as passive underground filters. Micron‐scale particles of activated carbon are injected into contaminated aquifers using drilling equipment or injection wells. Once injected, the carbon particles attach to the soil. An in situ permeable barrier is installed across a contaminant plume through the injection of a number of points at suitable spacings. Groundwater flows through the barrier zone unimpeded while PFAS contamination is captured and contained by the activated carbon. The longevity of the barrier is determined by the quantity of carbon emplaced relative to the contaminant flux. Barriers are typically designed to last for years (decades), after which time, carbon re‐applications can be made, if required. Principal differences between the approaches are the scale of operation and maintenance requirements, and, for P&T, the bringing of PFAS‐impacted water above ground to treat. This generates a filtration medium that is contaminated with PFAS, and which therefore requires handling as a PFAS waste with attendant liability. Hydraulic containment is also an active technology (requiring external energy input) and requires the operation and maintenance of pumping and filtration equipment. In situ CAC barriers are passive (powered by natural groundwater flow) and have no operation and maintenance requirements. They do not bring PFAS‐impacted material above ground and do not generate waste. Performance data of the installed P&T hydraulic containment system were analyzed to estimate the time to remedial completion using the system alone. Data extrapolation supported by statistical analysis indicates clean‐up targets will not be reached within 100 years of pumping. It is not realistic for P&T to be regarded as a means of aquifer clean‐up as the aquifer will remain contaminated for the realistic future. Comparison is made between P&T and CAC on their common basis as containment approaches. The goal is to reduce the exposure of down‐gradient receptors to PFAS.

ABSTRACT Screen printed and thermoformable conductive silver inks are one of the key building blocks for producing high performing Flexible Printed Electronics (FPE) and In-mold Electronic (IME) structures. Such novel electronic structures could potentially be used as capacitive touch sensors for Human Machine Interface (HMI) devices in consumer goods, white goods as well as in automotive electronics. In this study, we present the results of the electrical reliability performance of two types of silver inks, which are suitable for polyethylene terephthalate (PET) and polycarbonate (PC) based substrates to produce FPE and IME structures, respectively. Five different types of harsh environmental reliability tests were carried out to evaluate the electrical performance of these silver inks. The effect of various electronic circuit processing conditions, such as drying, thermoforming and injection molding, on the electrical resistance under various reliability test conditions was also evaluated. The results show that the silver inks are stable under such accelerated environmental reliability test conditions and are recommended for use in the construction of FPE and IME structures.

Abstract The longevity field has received an influx of capital and talent over the past 5 years, but it is unclear where directing these resources would result in the biggest positive impact. We aimed to establish a systematic, rigorous and unbiased way to identify the areas where increased investment would accelerate progress across the whole longevity field the most. To do so, we surveyed ∼400 participants across various sectors of longevity, asking them to 1) identify the major bottlenecks they are experiencing, 2) list their most needed solution, and 3) rate the potential efficacy and barriers to development of various aging intervention strategies. We built a classification system of Bottlenecks and Solutions based on grouping related answers and found the most frequently listed bottlenecks to be 1) lack of validated aging biomarkers; 2) an overall lack of funding; and 3) lack of good models for aging studies. Surprisingly, the most wanted solution was greater availability of large public datasets. Indeed, a common theme across all answers was the need for a new data-centric structure of scientific research, where large datasets are routinely gathered and made available, access walls are removed, protocols are standardized, negative and unpublished data are shared, and AI systems are released on the data for automated discovery. Finally, a lack of regulatory clarity was listed as the biggest barrier to development across all interventions, whereas cellular reprogramming, organ replacement, and genetic medicine (gene therapies and gene editing) were perceived as the intervention strategies with the highest potential for increasing healthy lifespan. We provide these data as a resource for funding agencies, philanthropists, entrepreneurs and newcomers to the field as a means to identify high impact areas to fund and work on.Key takeaways395 Participants were surveyed for their biggest bottlenecks and most needed solutionsTop Bottlenecks: lack of Validated Biomarkers; Overall lack of Funding and Slow & Expensive Models.Top proposed Solutions: more Public Datasets; improved Regulatory Path; and Overall More Funding.Bottlenecks and Solutions vary substantially across industry areas.Rapamycin and calorie restriction are perceived as the most efficacious interventions in the near term.Somatic reprogramming, organ replacement, and genetic medicine are perceived as the most efficacious interventions in the long term (25 years).Sirtuin and NAD targeting therapies are seen as the least efficacious interventions in all time-frames.Across all interventions, Regulatory Issues are perceived as the most severely inhibiting factor in the development of the intervention.