Complex Integrated Systems

Introduction

Moore’s Law and monolithic implementations

For much of the latter half of the last century, the evolution of electronics was focused on increased digitization and miniaturization. This was implemented using a homogeneous implementation fabric—digital processing on silicon. Moore’s Law ensured that viable economics and performance targets could be met. Even today, work continues on this concept with further reductions in feature size and integration of new functionality on-chip (e.g., silicon photonics).

Beyond Moore and system-in-package

Further reductions in on-chip feature size have become ever more costly as the basic physics has limited further easy gains. The concept and practice of “heterogeneous integration” – different functions implemented on different implementation fabrics – has been adopted throughout the industry. Each fabric is optimized for the needs of a small set of similar functions. Those fabrics (often separate die) are integrated into a single package (system-in-chip).

The approach has benefits in better power efficiency, smaller implementations, and sometimes simpler processes. To take advantage of the better yields and easier handling of smaller dies, even homogeneous functions such as memory are now split across multiple die and vertically stacked in a single package.

Redefining packaging

The system-in-package (SiP) concept can also be limiting. Recently, concepts and implementations that eliminate or redefine the role of the package have emerged. Direct attach of bare die to module-sized substrates, have eliminated traditional packaging in some 5G mobile handset processor modules. Use of antenna-in-package for mmWave systems redefines the role of the package, adding functional requirements. High-speed printed circuit boards (PCBs) are increasingly being implemented as substrates.

Complex integrated systems

Complex integrated systems (CIS) combine different types of functions—e.g., digital, analog, optical, micro-mechanical, power-related, structural—in a single system to ensure the best solution fit for the product and its end market. These are systems where:

1. For any given function, the specialized implementation technology and/or material system that provides the best performance at the right cost point is chosen. 

2. The different function implementations are integrated using the most appropriate interconnect and packaging solutions. 

3. Multiscale, holistic approaches are essential for design, simulation, assembly and test across the complete, sustainable product lifecycle, including manufacturing.

4. The resulting supply chains intelligently integrate the capabilities, expertise, and business practices used across wafer fabrication, chip/die packaging, module assembly and final system assembly.

CIS products are designed by leveraging a rich portfolio of active components, structural elements, and functional materials such as:

• Optics—CMOS, lens, mirror, displays

• Photonics—Photonic IC (PIC), fiber, light emitting diode (LED)

• Electronics—passive, active, integrated, printed

• Mechanics—enclosures, motors, servos, micropumps

• Substrates—rigid, flexible, stretchable

• Materials—electrical, thermal, optical, mechanical

• Sensors

SiP devices, heterogeneous integration, and chiplets are just one set of possible integrations for CIS solutions.  Other highly integrated assemblies also come in under the definition of CIS, including direct attach to rigid and flexible substrates, mixed optical/electrical assemblies, compact sensor modules, etc.

As shown in Figure 1, CIS can involve integration of multiple lower layer hardware components to a higher-level unit, starting from wafer to components to modules to systems. It is important to note that software and networking are not considered here.

Scope

The scope is set mainly by the definition of CIS above. The rest of this topic is organized as follows:

1. Key applications that are enabled by CIS are discussed in some detail.

2. The implications for the organization of the electronics manufacturing ecosystem are explored.

3. The impacts on the major facets of the full product lifecycle are discussed.

4. Technical needs, gaps, challenges and solutions are outlined.

5. List of recommendations for individual firms and the electronics industry ecosystem are provided.

Applications

Even today, there are some significant CIS applications in the marketplace, e.g. personal devices such as smart watches and hearing aids, high-end SiP solutions for compute and graphical processing, etc..

However many new critical applications that are now scaling into mass adoption require even further integration across a wider range heterogeneous technologies.  These new market opportunities are then the critical drivers for complex integrated systems.  In aggregate, the market opportunities associated with CIS solutions have significant annual growth rates and companies are investing tens of billions of dollars to address these opportunities.

Sample applications that require CIS include:

• Massive Wireless Broadband with 5G mmWave Systems

• High-Performance Computing Applications in Edge Devices and Data Centers

• Augmented reality/virtual reality/mixed reality (AR/VR/MR) Devices

• Advanced Driver Assistance Systems–Passenger Vehicles

• Integrated Photonics

CIS Ecosystem—Blending Manufacturing Verticals

The manufacturing ecosystem for CIS will see significant changes in supply chain roles.

The assembly of CIS-enabled products requires a combination of different processes, tools, and equipment that have traditionally existed in different electronics manufacturing verticals (wafer foundry, outsourced semiconductor assembly and test (OSAT), and electronics manufacturing services (EMS)).  In the past companies were hesitant to extend or change their role in the value chain due to the inherent barriers to entry (e.g., capital expenditure (CAPEX), operational expenditure (OPEX), manufacturing facilities, etc.).  These barriers no longer present a concerning risk profile for companies considering CIS services because demand has increased and manufacturing revenues are growing at attractive, sustainable rates. 

This blending of roles in CIS supply chains is illustrated in Figure 2.   Different players may become dominant through vertical integration in different market segments.  Consolidation is likely due to savings arising from increased efficiency and accountability.  However, it is challenging to predict the shape of new supply chains due to the tensions between technology investments needed; the degree of product mix for given market segments, and the margins available.

Companies that offer CIS design engineering and manufacturing services have acquired the necessary capabilities and equipment from the different verticals, thereby offering complete product assembly at one facility.  This provides the customer with the most secure and efficient supply chain.  The following list of processes—which in the past would have been available at companies representing multiple manufacturing verticals—can now be found at a single CIS services company:

• Wafer-to-wafer bonding, die-to-wafer bonding

• Wafer thinning

• Wafer, panel and die handling

• Wafer probe and test

• Interconnects/bumping

• Precision placement

• Micro-dispensing

• Artificial intelligence (AI)-enabled active alignment

• Wire bonding

• Handling/placement of electro-optical, electromechanical, semiconductor devices,

• Encapsulation, evaporation, plasma, nanocoating

• Surface mount technology (SMT), higher level assembly (HLA), final assembly test and packaging (FATP)

In addition, supply-chain management for CIS needs to include tight quality control of input components, e.g., in terms of technical cleanliness. The logistics for assembly of the CIS product minimizes the handling and shipping of unfinished modules from location to location, thereby minimizing supply chain disruption and reducing the product carbon footprint.

Impacts on the Complete Product Lifecycle

Any quick survey of the needs and challenges shows that realization of products as CIS is much more than just technologies for integrating previously separate components.  Full lifecycle support is needed, from design to manufacture to test.  Serious investment is needed, in people, infrastructure, and processes.

Consider each element within the product lifecycle, as follows:

• Design for CIS

• Smart Manufacturing

• Testability/In-Field Reliability

• Sustainability

Technical Needs, Gaps and Solutions

The technology issues surrounding CIS, the associated needs, technology status of those needs, as well as gaps and challenges to overcome, are summarized below. The time period considered is from 2024 to 2034.

For each need, the status of today’s technology is indicated by label and color as follows:

Table 1: Color key for technology status

Table 2. CIS Needs, Gaps, and Today’s Technology Status with Respect to Current and Future Needs

Table 4 considers approaches to address the above needs and challenges. The evolution of these is projected out over a 10-year timeframe using technology readiness levels (TRLs).

Table 3: Color key for technology readiness levels

Table 4. Complex Integrated Systems, Potential Solutions

Recommendations

Successful design and manufacturing of CIS electronics requires new technology for miniaturization and integration.  However, delivering compact integrated functionality is only part of the challenge.  As discussed above, the full product lifecycle needs to be addressed, from workforce development to design and test, to end-of-life repurposing and recycling.

For individual companies, a number of actions are required:

• Technology development focused on miniaturization.

• Adoption of system design tools that determine the trade-offs between different technologies and integration architectures. 

• Adoption of design for test, for manufacturing, and for sustainability as core design principles.

• Investment in new process and manufacturing capabilities, opening up new integration possibilities within a single facility.

• Facility equipment and processes that accommodate both cleanroom environments of back-end of line packaging and the flexibility of board assembly capabilities.

More broadly, we call for improved CIS situation awareness and a concerted effort to build a CIS community focused on collaborative, cross-industry initiatives for realizing the following:

• Standards and frameworks to support cross-supply chain traceability of materials, components, and their associated test data for CIS, building on existing standards such as IPC-1782⁵.

• Standardization of data exchange formats within CIS electronic design automation (EDA) flows.

• Standardization of physical form factors and physical interfaces for chiplets.

• Standardized assembly techniques to ease materials extraction for recycling and (in the longer term) component extraction for reuse.

• Strong cross-technology knowledge base for designers, manufacturing engineers, test and manufacturing technicians that now need to work with multiple technologies during design and manufacture.  This includes increased multi-disciplinary thinking and system design in undergraduate-level technical courses.

If the above issues are successfully addressed by the industry, then CIS electronics will have significant positive impact both on commercial opportunities for individual companies and on targeted societal challenges.

References

1. iNEMI, IPC, “Complex Integrated Systems: The Future of Electronics Manufacturing“, whitepaper, https://go.ipc.org/complexintegratedsystems, March 2024.

2. SEMI, “SEMI E30 - Specification for the Generic Model for Communications and Control of Manufacturing Equipment (GEM)”, https://store-us.semi.org/products/e03000-semi-e30-specification-for-the-generic-model-for-communications-and-control-of-manufacturing-equipment-gem.

3. IPC, “IPC-HERMES-9852: The Global Standard for Machine-to-Machine Communication in SMT Assembly”, https://www.the-hermes-standard.info/.

4. IPC, IPC-2591-Version 1.7: Connected Factory Exchange (CFX), https://shop.ipc.org/ipc-2591/ipc-2591-standard-only/Revision-17/english, August 2023.

5. IPC, IPC-1782 - Revision A - Standard Only: Standard for Manufacturing and Supply Chain Traceability of Electronic Products, https://shop.ipc.org/ipc-1782/ipc-1782-standard-only/Revision-a/english, November 2020.