1 Foundational Technology Layers

The state of the art in electronic packaging worldwide is characterized by a strong emphasis on miniaturization, integration, and reliability. Globally, there is a significant focus on developing advanced packaging technologies that enable the integration of multiple functions and components into smaller and more efficient packages. This includes the use of advanced materials, such as organic, silicon or glass substrates and advanced interconnect technologies, as well as the development of innovative manufacturing processes, such as 3D integration and wafer-level packaging. Main research focus worldwide is on chiplets technology. Additionally, there is a growing emphasis on improving thermal management and reliability through the use of advanced simulation and testing methods.

The European industry is actively involved in revitalizing electronic packaging technologies and is a key player in the global landscape, especially in the field of electronic packaging for harsh environments. European companies and research institutions are at the forefront of developing innovative packaging solutions for power electronics, contributing to the overall state of the art in electronic packaging worldwide. Further collaborative efforts and research initiatives are required, to keep the European industry in leadership position.

The Advanced integration solutions challenge envisions a future where electronic devices are smaller, more efficient, and reliable. The expected outcome is to establish Europe as a global leader in advanced packaging technologies, with a focus on miniaturization, integration, and reliability. Through initiatives like the Pack4EU project, the vision is to develop innovative packaging solutions that enable the seamless integration of multiple functions and components into smaller and more efficient packages. This will be achieved through 9 recommendations (source Pack4EU):

• Implementation of an Industrial Transfer Instrument dedicated to semiconductor packaging bridging the gap between prototyping and production.

• Establishment of a High-Level Packaging Board composed of industry leaders to guide strategic directions driven by market needs, ensuring innovation in packaging standards and practices.

• Implementation of a Technical Expert Group for developing and updating a Roadmap for Advanced Packaging in Europe.

• Creation of Open Piloting Facilities for small and medium volume production as a seed for growing European Advanced Packaging capabilities.

• Development of tools and methodologies for a Design-to-X approach & Standardization for an OPEN European Co-Design Ecosystem.

• Consolidation of international relationships through open calls on Sustainable Packaging Materials and Substrates, for example in liaison with IAM4EU and ERMA.

• A strategy for training and skills development including: Bridging research and education and facilitating international exchange on training through an EU Education Hub and Building a framework for access to EU-funded research pilot lines for students.

• Support for Small and Medium Enterprises through dedicated open calls applying, for example, cascade funding schemes or other funding instruments dedicated/adapted to SMEs.

• Creation of a Pan-European Network for Advanced Packaging to federate and strengthen the European ecosystem.

Smart CMS require a multitude of processes: silicon and other micro- and nano-processing, additive manufacturing, lamination and other interconnection and assembly technologies, as well as hybrid combinations. To increase the integration density and combine the above-mentioned features, many different integration and packaging technologies are required, such as thin film processes, embedding, classic assembly and joining methods, both for single components as well as modules.

Heterogeneous integration, from components up to the system level, requires-engineering on many technology domains, such as power, signal integrity, EMC, thermal and mechanical. All such domains and their hardware and software interplay (power and communications) must be designed together to ensure a high device- and system-level performance and the necessary integration. The challenge here is to combine all these domains in the design and simulation of integrated systems, often with inadequate information of all the properties of the included materials, components and processes. Where possible historical data and related algorithms should be used to predict and optimize system level performance. This may involve changing sensing intervals and/or how and where data is processed and routed. Furthermore, standardized and interoperable design and simulation methods that enable and support such multi-physics and multimodal design and manufacturing must be addressed, with the possibility to parameterize not only the material parameters, but also the system parameters, e.g. variability in the quality of the contact (e.g. thermal, mechanical) between the transducer and the ambient energy sources in the case of power harvesting. Modelling and design tools for thermal, mechanical and electrical characteristics in small 3D packages, including moulded and additive manufacturing methods are needed, linking to the Architecture and Design; Methods and Tools Chapter.

Heterogeneous chiplet integration enables the creation of highly customized, optimized and advanced systems by leveraging specialized chiplets for different functions. It enables faster and cost-effective manufacturing, as smaller chiplets have higher yields and can be produced independently. Furthermore, the ability to integrate chiplets from different manufacturers cultivate a more competitive, flexible and dynamic ecosystem. Designing systems with multiple specialized chiplets requires advanced design tools and methods to ensure the seamless functioning together. Each chiplet may have different power, performance and communication requirements, necessitating careful planning and integration (hardware and software). Developing cutting-edge interconnect solutions such as silicon, glass, and organic substrates-based interposers, through vias, and micro-bumping to enable high-density, high-bandwidth connections between chiplets. Thermal management is another key challenge, as densely packaged chiplets can generate substantial heat. Developing innovative cooling solutions and advanced materials is required to efficiently dissipate the generated heat to maintain performance and reliability.

Flexible electronics is an enabler to reduce the weight, volume and complexity of integrated systems and products, to create novel form factors and 3D design features. Currently, the majority of flexible electronics products are based on polyimide (PI), copper laminate substrates, etching of copper to pattern the circuitry, and conventional SnAgCu (SAC) soldering or anisotropic conductive adhesives (ACA) bonding processes for the assembly of discrete components on the substrate. Development towards smaller feature size in printing technologies increases the requirement of registration, or layer-to-layer alignment accuracy. Development of IC interconnection and bonding technologies, especially to flexible and stretchable substrates, is critical for improved performance, yield and reliability. In addition, pilot lines and fabrication facilities and capacities need to be developed.

In integrated photonics, if it comes to monolithic integration, the optical waveguides and devices are fabricated as an integrated structure onto the surface of a substrate, typically a silicon wafer. As a result of integration, complex photonic integrated circuits (PICs) can process and transmit light in similar ways to how electronic integrated circuits process and transmit electronic signals. New waveguide and active materials are constantly developed, e.g. SiN waveguides on silicon or Ge detectors and 2D materials for active components, such as modulators or detectors. The fabrication of PICs consists of a multi-faceted integration problem, including monolithic integration, heterogeneous integration of active components (e.g. laser sources), and high-speed driving electronics for e.g. high-speed communications above 100 GHz bandwidth, thermal management and other functionalities, such as fluidic functions for bio and medical sensing. Further system development regarding integrated photonics includes an often 3D assembly of electronics and photonics with passive optical MEMS as well as optics components like lenses, mirrors and beam splitters.

Integration and packaging technologies for quantum systems are key enablers to make quantum sensors and other systems industrially applicable. The integration and packaging in quantum technology poses several non-typical requirements for preserving the quantum coherence. These requirements include use of non-typical materials, such as extremely-low loss dielectrics and superconductors. Further, the packaging must support extreme cooling or even cryogenic operation, either by integrating a cooler technology inside, or by being inserted in an external cryo-cooler, which also entails vacuum operation. Thermal conductivity and handling of thermal expansion of different materials at every level, from wafer and chip level integration methods, to packaging and connection to room temperature are critical. Especially quantum computing requires multi-channel high-fidelity control and read-out solutions, with accurate synchronization and timing, from low-frequency to GHz range to the optical range of frequencies, depending on quantum system modality. Cryogenic electronics, cryo-CMOS or similar, are developed for solving these requirements, at the same time increasing the integration level of the quantum system, by introducing the control and readout elements closer to the qubits or other quantum devices.

The critical requirements to enable new advanced applications are to ensure sustainable and cost-efficient manufacturing while providing optimal performance and reliability. Further important developments include integration of different silicon IC components into miniaturized multifunctional modules following different SiP approaches, combining technologies such as flip chip, bonding, lamination and substrate materials such as silicon, glass, ceramics and polymers. Multifunctional integration also requires the development of multi-domain integration – e.g. the integration of photonic and RF functionalities into smaller form factors and together with sensors and CPUs.

For many portable devices e.g. Wireless Sensors Network (WSN) edge nodes, the power source in itself becomes a more complex challenge to integrate materials and devices, moving from traditional batteries and capacitors. This requires a complex combination of energy harvesting transducers, primary and rechargeable storage devices that need to interact with PMICs, MCUs, sensors and transceivers. Collectively, they need to make decisions at a node and network (gateway, cloud) level on when to use versus store energy and where to take it from based on energy available. The physical mounting of transducers and electrically controlling their characteristics (e.g. impedance matching) will also be critical to maximize their performance.

The challenge of integration processes, technologies and the manufacturing of smart CMS is mainly about dealing with the complexity of heterogeneous integration and scalable manufacturing technologies with different economy of scale approaches. These include “intensive” Si-like technologies, or “extensive” printing-like technologies, which under different assumptions and processing paradigms can offer cost affordability and production scalability. Apart from high-volume applications such as medical patches and RF front-end modules for 5G/6G small cells, many industrial applications may require the availability of CMS in relatively small quantities over decades, which adds a new challenge to the scalability of manufacturing and implementation of the latest technologies.

The complexity and diversity of heterogeneous CMS substantially exceeds that of mere microelectronic components due to their multi-physics and multiple domain nature. In addition, the packages will include integrated functionalities, rather than being “passive” boards and frames. Integration and packaging methods should not compromise, but guarantee and even increase the performance of the interlaying components. Especially low-loss integration methods to enable integration of large RF systems or integrated photonics. These technologies would enable e.g. RF front-ends or active antennas for millimeter wave frequencies enabling novel beyond-5G telecom solutions, or in integrated photonic communication and sensing systems. Merging different PIC technologies to compensate for missing functionality in individual cases is based on a variety of technologies, such as die flip-chipping, wafer bonding, micro-transfer printing, edge coupling, and others. Amongst current examples, one that is particularly pronounced is the integration of III-V light sources with silicon photonics, which is missing from silicon technology on its own.

In this multifunctional and multimodal integration at CMS level, the development of manufacturing methods that meet the accuracy and repeatability criteria of high-quality and high-reliability products for a broad range of applications and constraints (physical, mechanical, thermal, environmental) is challenging and needs development. This method development shall be accompanied by process modelling leading to a digital twin for manufacturing allowing documentation, simulation and improvement of manufacturing challenges in a digital environment (see also Chapter 2.4).

Additive manufacturing can provide structural and functional solutions for smart CMS integration that are not feasible with traditional methods. These methods will enable zero-defect manufacturing starting at lot one. Although additive manufacturing also improves manufacturing flexibility, solutions for the cost-efficient scaling of these fabrication methods must be addressed. 3D CMS integration methods will need to be developed to provide greater functionality and miniaturization in a cost-effective, sustainable and scalable way.

With respect to this multi-modality of heterogeneous integration methods, the key focus areas are divided based on the main technologies: advanced packaging and SiP technologies, integrated photonics, flexible electronics, quantum systems and manufacturing methodology, as follows.

• Advanced packaging and SiP technologies

  • Robust heterogeneous 3D integration of light sources, sensors, actuators, electronics, processing units, communication, RF front-end components and energy supply into miniaturized systems, often working in harsh environments.

  • Embedding of power sources (energy harvesting transducers, batteries, supercaps, etc.) into a package (PwrSiP) and on a chip (PwrSoC).

  • IC carriers with integrated voltage regulator and capacitance increasing the power delivery efficiency, as well as finer structuring in IC carriers: below 5/5µm line width and spacing and finer micro-vias (below 15µm diam.).

  • Multi-node chiplets for compute applications involving high-speed chip-chip interconnections with high-resolution electrical and optical routing in substrate or redistribution.

  • Embedding of power sources, ASIC drivers and audio MEMS sensor and actuators such as microphones and micro speakers into a heterogeneous SiP.

  • Integration with biological and molecular systems, including fluidics and surface coatings and functionalization materials and methods for multi-functionality on the same base structures, e.g. biosensor arrays on Silicon.

  • New functional materials for packaging that enable integration of sensing or other functionality or enhanced functionality into the packaging itself, e.g. packaging as a part of the antenna or sensor functionality, e.g. embedded heatsinking/spreading to increase the thermoelectric energy harvested.

  • New materials and methods for housings and coating features and new substrate materials for specific requirements: high power, high frequencies, disposable, bio-compatible, non-fossil, harsh environments.

  • Rapid prototyping and manufacturing technologies (additive manufacturing, 2D and 3D additive technologies, etc.).

  • High-performance materials for passives enabling close coupled passives for high-density heterogeneous integration such as magnetic cores, high-k dielectrics.

  • Ultra-dense and small interfaces in all integration levels, from chip assembly and packaging to component and module level connectors and connections.

  • Integration of different sensors and sensor hubs for sensor fusion (e.g. combination of acceleration sensor, microphone, microspeaker for enhanced noise cancellation).

  • Manufacturing and characterization processes for hermetic sealing of components or subsystems with low leakage level.

• Integrated Photonics and co-integration with electronics

  • Photonic-electronic system integration based on integrated photonics, including high-speed RF electronics, MEMS/NEMS/MOEMS sensors, etc.

  • Multi-domain electro-photonic integration and electro-optic co-packaging.

  • Wafer-level integration of photonic and electronic components for smart emitters and detectors.

  • Enabling electronic-photonic systems by heterogeneous integration of active components on PICs (III-V semiconductors, ferroelectrics, ultra-low-loss waveguide materials). Heterogeneous integration processes and equipment for integrated photonics, including high-precision component placement and bonding, integration of active components on PICs (III-V semiconductors, ferroelectrics, ultra-low-loss waveguide materials) as well as low-loss fiber coupling to PICs.

  • Quantum PICs: Integration of single photon detectors and sources and quantum photonic systems in PICs.

• Flexible electronics

  • Integration towards low vertical form factor (<100 μm) and the miniaturization of external matching networks through integration.

  • Submicron LAE fabrication processes and equipment (printing technologies in general, nanoimprinting, reverse offset printing, etc.) and automated manufacturing equipment for flexible electronics, including testing tools for electrical and non-electrical properties.

  • Interconnections processes and tools for flexible and stretchable devices and structural electronics (in glass, plastics, laminates, etc.).

  • New/alternative non-fossil, organic, biocompatible and compostable substrate materials, e.g. for implants, ingestibles, wearables, biosensors.

  • Adhesives, bonding materials and methods for integrating chips, light sources, drivers and sensors on flexible substrates.

  • Use of flexible Si-substrates for 3D form factors and for flexible electronics.

  • Integration and embedding of diverse materials and components such as antennae, PV panels, energy storage devices, magnetics, interconnect, heatsinks, displays, etc. in flexible or conformal electronics.

• Quantum systems

  • Materials and methods for integration and packaging of semiconductor electronics, Integrated Photonics and superconducting devices at cryogenic temperatures, including 3D technologies.

  • Integration and interfacing and cabling solutions for combining room temperature systems and cryogenic quantum components, sensors and systems.

  • Integration methods that enable scaling quantum systems efficiently, from wafer level 3D integration to module and system level.

  • Cryogenic electronics, cryo-CMOS and similar for increasing the integration level of quantum systems and enabling scaling up of quantum systems.

  • Development and miniaturization of cryogenic cooling systems, e.g. solid-state coolers.

  • Quantum PICs: Integration of single photon detectors and sources and quantum photonic systems in PICs.

• Manufacturing methodology, characterization and testing

  • Automation and customization in CMS integration for large-scale manufacturing, including Industry 4.0 techniques, design for manufacturing based on production data techniques, and lot-size-1 manufacturing, e.g. BIST (built in self-test) capability of components.

  • Manufacturing and testing tools (including tests, inspection) for CMS, enabling zero-defect integration.

  • Process modelling approaches with focus on productivity, yield, trustability and distributed manufacturing.

  • Material properties database for simulation and reliability based on a standardized ontology.

  • Design of new materials from properties requirements by the means of Materials by Design, materials genome and digital design approach.

  • Energy-effective joining methods, e.g. low-temperature soldering; selective heating processes (i.e. inductive or reactive) to limit overall temperature impact to the system while packaging.

  • Self-powered embedded sensors for ongoing performance and condition monitoring and tracking of devices, e.g. for provenance, life cycle assessments, field failure analysis and authentic validation.

In 2019, world-wide e-waste exceeded 50 million tons and is forecasted to grow to 70 million tons in 2030¹. The European Union is one of the most advanced actors in e-waste recirculation processes. Indeed, in this region 42.5% of e-waste is documented to be collected and recirculated as product or component or recycled as material, whereas this is the case for only 9.4% in Americas and 11.7% in Asia². This can be explained by the clearer European and national political support for such initiatives.

However, as increased integration will cause the borders between CMS to become blurred, and more diverse and complex materials are used at each level, the dismantling of systems into their constituent components at the end of their useful life will become increasingly difficult. Many industrial ECS products have lifetimes extending to decades, thus the environmental regulations for recyclability cannot be known in detail by the time of product design. Nevertheless, early consciousness on the issue should preside the start of the product cycle. Based on identified challenges, regulatory measures under the Eco-design Directive are intended to establish design for energy efficiency and durability, repairability, upgradability, maintenance, reuse, repurposing and recycling. The European Commission presented its new Circular Economy Action Plan (CEAP) in 2020 to limit waste generation and encourage recycling, product repair and reuse. Part of this initiative is the digital product passport (DPP), which informs end-customers and businesses about products’ sustainability. In general, the concept of the circular economy (CE) builds upon well-implemented strategies to prevent waste generation and includes eco-design rules during product design phase and measures for re-using products and components after a use phase.

The European Platform on Life Cycle Assessment (EPLCA) includes information on the Product Environmental Footprint (PEF) and Organization Environmental Footprint (OEF) methods as a common way of measuring environmental performance (EU Commission Recommendation 2021/2279). The PEF and OEF are the EU‘s recommended LCA-based methods to quantify the environmental impacts of products (goods or services) and organizations.

ECS should produce smart systems not only as an enabler for, but also as an element of the circular economy, considering the sustainability of the ECS value chain and the products themselves. Focus should be on the sustainability of the CMS production, including processes, materials and maintenance during the primary lifetime. The recyclability of the product must already be considered in the design and manufacturing phase to enable repairability, upgradeability, reconfigurability, extension of lifetime, and repurposing/re-use in a second life application, and finally the recovery of components and materials for recycling.

Given the increasing burden of improperly dealt with e-waste and considering that a significant part of CO₂ emissions arises from the fabrication of the ECS themselves, extending product lifetime is important for reducing ECS-related environmental load. This needs to be addressed by designs that enable repair or replacement of faulty components, avoiding the replacement of the full module or system. To fight obsolescence, hardware and software upgrades should be supported, even in field conditions. Reducing CO₂ emissions during the lifetime of the system requires minimizing the power consumption at CMS levels while in operation by using low-power hardware and software technologies.

For increased sustainability of ECS, the circular economy, with its 9R framework (Refuse, rethink, reduce, reuse, repair, refurbish, remanufacture, repurpose, recycle and recover) and eco-design, are the main tools to reduce the environmental footprint of ECS. Life cycle assessment as a framework will be used for identifying hotspots and checking results of the intended reduction. But ECS themselves can also be regarded as an enabler for a more circular economy.

Future ECS products must be environmentally friendly, covering all aspects from materials, manufacturing, operation and maintenance during their lifetime, considering recycling at their end-of-life. Activities must start by ensuring circularity (eco-design, environmentally friendly materials and manufacturing), employing a low CO₂ footprint over the whole life cycle, and facilitating the transition to a circular economy, wherever possible. Outcome activities will address:

• Non-fossil, recyclable, biodegradable and compostable materials, without releasing any dangerous materials or having other negative impact on the environment.

• Eco-design including eco-reliability of sustainable and more modular ECS.

• Sustainability and reducing energy consumption and environmental footprint of the manufacturing and integration processes.

• Increasing energy efficiency of ECS, during manufacturing and lifetime, and end-of-life.

• Upstream considerations and design for repair, upgradeability, dismantling, materials separation and recycling, lifetime extension and system health monitoring, self-monitoring and healing.

• Performance and condition monitoring, traceability, (predictive) maintenance, repair, upgrading, reconfiguring, recharging, retrofitting and re-use in second life, including ecosystems and tools to support these actions.

• Product indexes and digital product passports for ECS.

• Enablement of novel sustainable business models.

The development of integration processes based on new design tools will allow the dismantling of components, as their recycling and recovery of materials (urban mining) is essential. Therefore, system design techniques move towards eco-design where we need to rethink the use of multifunctional components and modules. Design for component separation and recyclability is generally required in the selection of materials and the integration technologies. Recycling technologies, as well as new approaches to second life of ECS and re-use in new applications, must be advanced. For example, with the electrification of cars, the recycling and re-use of battery packs, modules, and individual cells, and finally, materials recovery from the cells, becomes more and more important. Finally, we should of course minimize the number of batteries we use and dispose and improve recycling of batteries and battery materials.

The use of new environmentally friendly, recyclable and non-fossil materials (or compostable/biodegradable materials) must be seriously considered to replace existing materials with low recyclability in the near future. The use of these materials can easily be extended to other parts of the system, and the development of biodegradable materials can also contribute to solving the problems of recyclability. Life cycle assessment (LCA) should be used as a design tool to minimize the ECS carbon and environmental footprint, considering the full life cycle and end-of-life.

• Eco-Design of ECS to promote circularity:

  • Use of replacement materials to comply with Restriction of Hazardous Substances Directive (ROHS) regulations (such as lead, mercury and other metals, flame retardants and certain phthalates, PFAS) and minimization of critical raw materials (CRM) dependence, including rare earths replacement for magnetics, inductors and power integrity.

  • Use of recyclable, biodegradable, compostable, non-fossil materials from sustainable sources in combination with the development of efficient and environmentally benign recycling techniques in accordance with the legislative agenda.

  • Less materials for higher functionalization.

  • Assessment of the environmental impact of ECS at the design stage, as a tool for sustainable ECS, using life cycle assessment (LCA) or similar framework.

  • Certified up-to-date data for LCA, PEF, PCR (product category rules ) and EPD (environmental product declarations)

  • Development of design, fabrication, integration, recovery, reconfiguration/reuse/ repairability and disassembly strategies for products (module dismantling, component recycling, material recovery) and also short-lifetime devices (e.g. single-use medical devices, radio-frequency identification, RFID, tags and printed sensors) to meet the existing and emerging regulatory requirements.

  • Improvement of system reliability as a means to guarantee and extend the lifetime of electronic products with the final objective of responding to material efficiency requirements and providing an optimal balance on a life cycle scale.

  • Increasing power efficiency of ECS during lifetime by using low-power techniques with context awareness or energy harvesting.

  • Extensive use of software to increase the sustainability of ECS by extending product lifetime through continuous optimization and adaptation, by making existing ECS more intelligent through the use of AI, in particular at the Edge, and by optimizing the resource usage through hardware and software co-defined strategies. Ensure the trustworthiness and reliability of the ECS, including its software components, with a special attention to approaches involving AI that must be secure, reliable and automatically and autonomously adapted.

  • Promote methodologies allowing for the co-design of ECS hardware and software involving simulations and realistic models, including AI-aided development tools, to continuously estimate key metrics. This must be complemented by instrumentation of the ECS hardware and software to continuously assess the achievements of the key figures of merit over the entire ECS lifetime (including shelf and post-decommissioning).

• Sustainable manufacturing of ECS:

  • Explore the extension of materials efficient wet/dry processes such as additive manufacturing methods and laser/mechanical subtractive processes. E.g. printing, that consume less resources (energy, materials, water) and are compatible with renewable materials, such as bio-based substrates. At the same time, additive manufacturing offers new design capabilities for circular, thin and flexible devices, even for single use (e.g. wearable electrodes) with specified end-of-life management.

  • Optimization of resources and processes in production environments with potential in-situ re-use and regeneration of base materials and chemicals.

  • Reduce energy consumption (and greenhouse emissions) in clean rooms through the use of renewable energy sources and energy-efficient technologies or tools.

  • Increase water reusage in electronics manufacturing facilities.

  • Improved analytics for hazardous production remnants

  • Inline sensors to research and mitigate environmental risks of GHGs, PFAS and hazardous materials and their integration to abatement systems and process equipment

  • Improve gas abatement systems.

  • Solutions to value scarce material use and to work on alternative technology integration strategies.

  • Breakthroughs and development in recycling processes and solutions for energy storage components, such as batteries.

  • Moving towards CO₂-neutrality and zero waste ECS economy.

• Sustainable products and business models:

  • Encouraging sustainable supply chains.

  • Introduction of product category rules and product indexes (including info such as energy and resource efficiency, durability, reusability, upgradability and repairability, presence of substances that inhibit circularity, recycled content, remanufacturing and recycling, carbon and environmental footprints, expected waste generation and information requirements) for components and systems to encourage the use of LCA based environmental product declarations.

  • Digital product passports should be promoted, tested and then widely established.

  • Encourage new business models to see value in eco-design and recyclability.

  • Value repairability: An EU-wide repair index inspired by the French repairability index.

  • Condition monitoring for usage as well as for health/performance and anomaly detection.

  • Improve efficiency of e-waste recyclability by robotics, thereby increasing new value streams and business through reuse.

  • Life cycle traceability of components and systems to capture condition, carbon footprint, authenticity and recyclability.