5G PCB: Circuit Boards Supporting 5G Technology
Since the significant commercial breakthroughs of 5G technology in 2019, numerous countries have launched their 5G networks. These developments have had a profound impact on the field of communications. Alongside the adoption of Active Antenna Unit (AAU) technology, which incorporates highly integrated RF modules in base station construction, the utilization of the mmWave frequency band has emerged as a pivotal aspect. This frequency band offers greater bandwidth and faster data transmission speeds, making it a key enabler of 5G networks. To effectively support these frequency bands, more sophisticated antenna systems and 5G PCB have become indispensable. In this article, FS Technology will delve into the world of 5G-integrated circuit boards and provide a comprehensive set of design guidelines to assist your project.
Integration of 5G Technology and Circuit Boards
What is 5G
While there is a prevalent notion that 5G technology primarily offers faster video streaming and higher data costs, its influence extends far beyond mere entertainment. 5G holds the potential to reshape various facets of human life, including but not limited to autonomous driving, advanced telemedicine, and immersive virtual projection.
5G, short for the fifth-generation mobile communication network, represents a significant evolution in network technology. This transition from 1G to 5G essentially involves a shift in radio wave frequencies. Higher frequencies offer greater bandwidth and consequently facilitate faster data transmission. This fundamental change underpins the stark contrast between 4G, with an average speed of 100Mbps and a latency of 30-50ms, and 5G, boasting speeds of up to 10Gbps with a latency as low as 1ms.
What is PCB
PCB, or printed circuit board, is regarded as a core component of modern electronics, and it is classified as a high-frequency PCB in the 5G field. In traditional applications, the main job responsibility of the circuit board is to undertake component support and provide electrical connections, but in 5G it is far from enough.
5G signals primarily operate within high-frequency and millimeter-wave frequency bands, necessitating superior signal transmission capabilities with minimal loss. Furthermore, the low-latency requirements of 5G applications pose unique challenges and constraints for conventional PCBs.
High-frequency PCB is purpose-built circuit boards tailored to the demands of high-frequency signal transmission. Leveraging low-loss materials, precise impedance control, RF filters, and RF antenna design, these PCBs are meticulously crafted to cater to the exacting needs of 5G technology.
5G PCB Design Challenges and Solving
Signal Transmission Integrity
The elevated demands of 5G PCB applications bring forth dual challenges for designers and manufacturers—high frequency and miniaturization. To address these requirements, a primary strategy involves the utilization of thinner traces to optimize I/O in the design. However, employing these thin traces places greater demands on the PCB manufacturing capabilities of producers and entails the risk of signal attenuation. In this context, the conventional etching process encounters difficulties, potentially resulting in cross-sectional trace defects that disrupt impedance and, consequently, affect the signal integrity of 5G PCB.
To tackle these issues, manufacturers must enhance microfabrication technology to ensure precision in wiring. Additionally, the establishment of multiple inspection checkpoints, such as AOI and X-Ray, is crucial for assessing the manufacturing quality of both inner and outer layers.
Signal Receive Compatibility
After extensive validation, Massive MIMO has emerged as the optimal technology for achieving breakthroughs in signal transmission speed. It’s a multi-antenna technology that augments the number of antennas in both base stations and terminals, resulting in a significant enhancement in wireless network performance. However, it also introduces compatibility issues and presents new challenges.
Traditional PCB is designed to operate within an acceptable frequency range of 600 MHz to 5.925 GHz, utilizing bandwidth channels of 20 MHz. In contrast, 5G signals can extend into the mmWave frequencies, reaching 28GHz, 30GHz, and even up to 77GHz. Furthermore, 5G information systems are capable of handling frequencies both below 6GHz and above 400MHz in terms of bandwidth channels.
To adapt to these changes in signal reception, designers must not only control the impedance of the PCB’s copper traces but also upgrade the substrate material employed. Conventional substrates typically exhibit dielectric constants ranging from 3.5 to 5.5. It is evident that meeting the stringent requirements of 5G PCB for substrates can be challenging, necessitating the exploration of superior materials to ensure compatibility with signal reception.
EMI Electromagnetic Interference
The integration of high-frequency signals in 5G PCB necessitates a proactive approach to tackle potential electromagnetic interference issues during the design phase. Designers must provide solutions to mitigate these challenges effectively.
Employing filter connectors to suppress both conduction and radiation interference is a viable solution. Currently, industry-standard options such as TE DEUTSCH, Smiths Interconnect, and AVIC Optoelectronics rectangular filter connectors are widely recognized as top choices. If concerns arise regarding component procurement, FS Technology procurement team can provide assistance. We offer component procurement services at competitive prices, ensuring the sourcing of components through reputable channels.
The second strategy revolves around optimizing routing design. This entails adding shielding to critical signal lines, adhering to vertical and horizontal routing principles, and minimizing trace lengths, among other considerations. It is imperative to ensure that optimization measures consistently align with PCB design rules to prevent unnecessary complications.
In 5G PCB design, conducting a thorough post-design review is paramount. This involves scrutinizing the closed and open loops of traces to eliminate potential loop antennas. Additionally, it is crucial to verify the proximity of decoupling capacitors to the power supply pins while minimizing the area enclosed by power and ground traces.
The demands of 5G technology, particularly the need for higher signal transmission speeds, result in PCBA that consume more resources and handle larger currents during operation. This increased current flow carries the risk of generating excess heat on the board’s surface. Furthermore, 5G PCBs are characterized by high-frequency, high-speed, and high-density designs. These densely packed components can lead to heat accumulation issues and hinder effective heat dissipation. Ultimately, these challenges can manifest as problems such as copper wire peeling, delamination, shrinkage, and warping due to insufficient heat dissipation.
To combat heat-related problems, several strategies can be employed. Firstly, selecting the appropriate substrate material is crucial. Materials like IMS PCB, with thermal conductivity 8 to 12 times that of FR-4, offer superior temperature management capabilities. Secondly, a well-thought-out heat dissipation design should be implemented, which may involve the use of copper layers, thermal pads, heat sinks, and other cooling solutions. Equally important is the performance of thermal simulation tests on the 5G PCB once the design is complete. These simulations help analyze the heat distribution among various components and areas, allowing designers to identify and address potential thermal issues proactively.
We'd love to hear from you