As 5G technology continues to usher in unprecedented levels of smart connectivity, the demand for faster information processing has become increasingly critical. Since 2010, the growth of data centers has led to a 30% increase in their energy consumption. Moreover, the introduction of new 5G innovations in the market brings substantially greater power densities, resulting in elevated heat levels and a pressing need for advanced thermal management solutions.
Electronics manufacturers require high-performing materials that can meet the rigorous specifications of 5G technologies to ensure their seamless operation, and silicones have demonstrated their capability to effectively support the 5G ecosystem.
The material selection landscape
While there is a wide array of protective materials that offer distinct advantages for electronics manufacturers in specific areas, many often come with significant drawbacks in other aspects. For instance, acrylics offer rapid curing that enhances electronic assembly efficiency, but tends to soften at elevated temperatures. Polyurethanes and urethanes are exceptionally durable materials that resist mechanical wear, however fall short in mitigating the stresses resulting from rapid and uneven heating and cooling. Epoxies excel in humidity resistance but are susceptible to cracking, potentially leading to sealant, coating, and adhesive failures. Parylene, while chemically inert, supports only limited throughputs during electronic assembly, making it less suitable for mass-produced items like laptops and smartphones.
Silicones, on the other hand, strike an appealing balance of properties for high-volume manufacturing and facilitating high-speed connections. They offer effective solutions for challenges related to adhesion, encapsulation, coating, and EMI shielding. These elastomers exhibit resilience against moisture, chemicals, and contamination, all while maintaining a soft and flexible nature. Their hydrolytic stability is useful, especially given the increased installation of 5G infrastructure in regions with high humidity, rain, or snow.
Importantly, silicones can withstand the elevated temperatures associated with 5G technology, providing long-lasting heat resistance without significant loss in their inherent properties. Thanks to their low modulus, silicones can also alleviate some of the stress that occurs when materials expand and contract at differing rates due to varying coefficients of thermal expansion (CTEs). Silicone resins with low levels of volatile organic compounds (VOCs) also can meet regulatory requirements and address environmental health and safety (EHS) concerns.
5G consumer devices
Silicones play a pivotal role in driving 5G electronics across a wide spectrum of applications, ranging from advanced driver-assistance systems (ADAS) to smartphones. In the context of smartphones, silicones are the preferred choice of designers due to their consistent ability to dissipate chip heat and properties such as anti-cracking, stress-relief, and shock absorption, which effectively safeguard against wear and tear. Additionally, silicones are resistant to both high and low temperatures and minimal cure shrinkage. This becomes particularly important when considering smartphone displays, where the need for waterproof sealing necessitates the prevention of air gaps between the display panel and cover.
Not just limited to smartphone design, other silicone applications target smartphone accessories and 5G smartwatches. For example, silicone thermal adhesives are used inside smartphone chargers, which tend to quickly heat up. Bonding and sealing for cable connectors can combine primer-less adhesion with instant green strength for better adhesion and good reworkability for less waste with silicones. These features are important for 5G smartwatches - compact devices with chips that produce significant heat and may require rework or removal of residues during product assembly.
In situations where EMI-shielding adhesives become necessary for ADAS in automobiles, electrically conductive silicones facilitate flexible joints and boast high elongation to prevent breakage. Beyond this, silicones are found in electric vehicle (EV) battery packs and ADAS sensors designed for light detection and ranging (LiDAR) technology. Silicone pottants, due to their excellent dielectric properties, play a vital role in safeguarding connectors, power supplies, sensors, transformers, amplifiers, and high-voltage resistance packs within these systems.
Ultimately, the heightened reliability of 5G might hold greater significance than its increased and expanded capacity. To fully realize its potential as the network for all things, 5G necessitates a level of service capable of sustaining always-on technologies.
Carrier networks and heat dissipation
Silicones are not only enhancing reliability at the direct device level but also safeguarding the delicate electronics that underpin cellphone and data carrier networks. For 5G-enabled devices and equipment operating in millimeter-wave (mmWave) networks, the challenge is to support high-frequency communication alongside 2G, 3G, and 4G mobile-phone services ranging from 800 to 2100 MHz. As more 5G networks become available, the demand for 3.3- to 5.0-GHz communications will increase as existing 5G-enabled devices start utilizing untapped features.
In contemporary design practices, a common strategy involves employing a low-loss substrate coupled with a flip-chip device, along with on-module EMI shielding. Silicones infused with metal or metal-coated particles prove to be dependable for shielding while maintaining excellent electrical conductivity.
Commonly used to coat optical fibers, silicones also play a role in enhancing thermal management within carrier networks. In optical transceivers, silicone thermal gels are used to dissipate potentially damaging heat by transferring heat from the transceiver’s core components to a metal shelter that serves as a heat sink. In the module assembly process, silicone adhesives exhibit the capability to form robust bonds while simultaneously providing dependable EMI shielding and maintaining controlled levels of VOCs. Additionally, silicone encapsulants used for optical splitters demonstrate resistance to the development of microcracks resulting from environmental stresses, which can otherwise expand over time.
Cooling cloud and data centers
As high-speed, high-volume, hyperscale 5G data centers continue connecting the world, Synergy Research predicts that the global operational data center count will surpass 1,000 by 2024 and keep rapidly expanding. Currently, data centers are responsible for 1.5% of the world's electricity consumption, with 40% of that energy dedicated to cooling systems to counteract the heat generated.
To support the expansion of 5G data centers while meeting performance and sustainability demands, single-phase immersion cooling systems, powered by silicone technology, have emerged as a promising solution.
Thus far, three primary liquids have been used for immersion cooling. Each of these options offers improvements over traditional air-cooled systems but comes with specific performance challenges:
- Fluoro-carbon fluids are relatively expensive and raise significant environmental, health, and safety concerns, particularly in case of accidental leakage.
- Synthetic oils are associated with flammability and thermal instability concerns compared to other alternatives.
- Silicone fluids offer notable cost advantages but are incompatible with other silicone components.
However, hybrid silicone-organic fluid, engineered for single-phase immersion cooling, boasts exceptional thermal conductivity, ensuring efficient and cost-effective heat dissipation, and a remarkably low Global Warming Potential (GWP) score. This technology can penetrate smaller spaces close to materials requiring cooling, support the growth of server load densities, enhance computer performance, significantly reduce data center footprint requirements, minimize power consumption, and eliminates the compatibility issues associated with other silicone components in data center cooling operations.
The evolving 5G ecosystem
As the 5G ecosystem undergoes continual growth and evolution, silicone elastomers are poised to assume an even more substantial supporting role. While electronic designers have a plethora of material options, silicones stand out due to their distinctive properties, offering an attractive blend of characteristics that can effectively tackle crucial challenges like thermal management in the context of successful 5G deployments. By selecting the appropriate partner, electronic manufacturers can discover the optimal solutions to grow within the expansive 5G landscape.
