In the rapidly evolving landscape of high-speed 5G networks, enhancing device portability has become a pressing challenge. In every market, design engineers are confronted with the growing demand to shrink their devices, necessitating the downsizing of internal connectors. This article delves into the challenges of miniaturization across industries and highlights the product features of Molex's miniaturized connectors tailored for 5G applications.
The miniaturization of devices poses challenges to signal integrity
Since the advent of 5G phones, there has been a constant effort to pack more functionality into small spaces. In every market – particularly with the advent of 5G technology – design engineers are facing increasing challenges to redesign electronics to fit shrinking devices and integrate more functionality into compact spaces. This trend towards miniaturization necessitates making internal connectors even smaller and the vicious cycle continues.
In advanced applications like RF/wireless devices, consumer electronics, and data centers/edge computing, creating smaller components comes with challenges such as increased pin/signal density, whether for I/O or power, given the ever-changing user and market expectations.
The push towards using connectors with finer signal pitch presents challenges like the lack of internal space for EMI shielding, making the management of internal EMI effects difficult. Additionally, the close proximity of signal pins can cause cross-talk which can lead to signal attenuation, which in turn affects Signal Integrity (SI), impacting critical 5G speed performance.
Advanced 5G applications require saving PCB space, cost-effectiveness, and numerous design features to suit customer applications. This necessitates interdisciplinary expertise in electrical, mechanical, and manufacturing processes to provide microelectronic interconnects that operate at higher speeds while maintaining long-term reliability and commercial viability. To achieve miniaturization goals, designers must “think big to go small”, redefining connection innovation to meet communication, power, and I/O processing requirements.
As miniaturization continues to permeate every industry and application category, product designers must balance various factors such as power and thermal management, signal integrity and integration, component and system integration, mechanical stress, and manufacturability, all of which pose stringent challenges to device miniaturization.
Miniaturization is not just about connectors being made smaller
Miniaturization is not just about making components smaller; it also involves assembling these parts together and ensuring device makers can leverage the same design footprint (where possible) without the need for PCB redesign which would incur cost. Previously, many components are too small to be manually placed, forcing PCB manufacturers to turn to automated surface mount technology. Now, even with automated assembly, the manufacturing processes of handling very fine pitch connections on circuit boards also face a similar set of challenges.
Take the example of a typical micro connector pitch, which is the distance between the center of two adjacent pins. This distance has shrunk from well over 1 mm to 0.35 mm. Ultimately, the size of the pins will limit the amount of power they can carry or the frequency of the signal circuits they can handle. To some extent, compromises in size must be made to achieve high-speed performance.
Mechanical constraints are also a concern; and depending on the required applications, these connectors must sometimes be robust, waterproof and shock-resistant (if exposed to the environment) and cost-effective. The design aims to achieve mass production and be sold worldwide.Collectively, these constraints drive designers need to take a more wholistic approach to product design before entering the production process. For example, instead of continuing to shrink connector pins, designers can rethink the connector circuit layout, and this was what Molex did with the Quad-row board-to-board connector. This spectacular connector has 4 rows of staggered contact pins (hence the name “Quad-row”) and saves up to 30% of the circuit board footprint compared with the SlimStack SSB6RP variant. This is an innovative way to achieve smaller pin pitch without compromising the physical design. The results are unprecedented space savings while enabling high-density circuit connectivity.
With the continuous emergence of new features driving the development of the smartphone market, such as the increasing number of cameras in 5G smartphones, the industry needs smaller components to save space. The more recent model phones can be equipped with 4 or 5 cameras, reaching a saturation point in terms of camera quantity. Added to this are the challenges of 5G applications that create new demands for miniaturization within the telecom industry.
Currently, 5G is the biggest factor, as smartphones require more antenna modules and more RF functionality internally. Additionally, all functions related to 5G require more power and hence larger batteries, which puts pressure on design engineers to shrink other necessary components.
The RF connectors is a good example, in the past, engineers used coaxial cables to transmit RF signals between boards, but these are now replaced by smaller RF connectors, which form part of new miniaturization trends. Using RF connectors with different heights allows manufacturers to optimize component placement in the Z-axis. However, achieving this transition is not easy. Since 5G operates at higher frequencies, other parts must be redesigned to avoid signal leakage. To meet this demand, engineers had to develop new gap-less manufacturing methods for connectors – a simple demonstration of the complex interactions between engineering disciplines for the next-generation technology.
Flexible board connectors overcome miniaturization challenges
Molex is committed to driving the path of miniaturization with decades of experience in addressing challenges and trade-offs. Through the global engineering and manufacturing leadership team, Molex provides interdisciplinary expertise and unparalleled collaboration to support customers' ever-changing needs. The introduction of the 5G25 series Flex-to-Board connector addressing the needs of 5G millimeter-wave RF applications is one such example.
This miniature connector offers excellent SI performance for high-speed, extreme RF applications and robust mating features as well as PCB space savings required for compact 5G mobile and other communication devices require, to meet high-frequency (25 GHz) demands. Molex's proprietary RF terminal contact shielding and isolation features maintain the high-level SI performance expected in mission-critical 5G applications.
Contrasted to their physical sizes, the intricate yet mechanically rugged features of these miniature connectors explain their high electrical reliability. The connector’s uniquely designed shield offers full EMI shielding and highfrequency capability for superior EMI reduction and SI performance while supporting mating positioning. It also protects against potential RF contact buckling and shock caused by accidental drop.
Connectors with industry-leading signal integrity
The Molex 5G25 series supports high-frequency 5G applications up to 25 GHz, enabling high-speed transmission. Mobile phone manufacturers, RF module developers and chip manufacturers can all benefit from Molex's industry-leading 5G millimeter-wave connection technology. The 5G25 series offers industry-leading SI performance and comprehensive EMI shielding (including both RF terminal and connector shielding), providing exceptional electrical and wireless signal performance and connectivity. Center shielding contact points are added within the socket or plug to isolate each row, further enhancing overall SI stability. Additionally, Molex's full-shield design provides excellent far-field gain performance, making it highly suitable for connecting 5G antennas to the rest of the transceiver.
The Molex 5G25 series is compact in size, supporting high-speed data transmission in space-saving solutions and provides additional protection against harsh environmental conditions. The signal pitch of the 5G25 series is 0.35 mm, with a mated height of only 0.7 mm, a body width of 2.5 mm, and a length of 3.6 mm, increasing the flexibility of printed wiring board (PWB) designs. Furthermore, the 5G25 enables RF antenna module and mobile device designers to combine RF and non-RF signals, reducing the need for additional connectors and saving more space and costs.
Designed for fast and reliable assembly, the Molex 5G25 series utilizes a 0.30 mm pitch (width) and 0.30 mm (span) fine alignment tolerance, offering high flexibility in alignment tolerances to speed up the entire assembly and production process. This allows for quick, fault-free assembly with an excellent "click feel" to prevent mismatching. The ultra-compact connector also has strong peel force, enhancing reliability and minimizing the load on assembly operators or automated assembly machines, providing the mechanical robustness required for product and operational reliability.
The Molex 5G25 series finds extensive applications in various industries including consumer applications such as AR/VR devices, smart home devices, smartphones, tablets, wearable devices, as well as military applications in aircraft avionics, drones, and unmanned aerial vehicles. The product’s ability to support 5G mmWave, Sub 6 GHz and 4G/LTE applications make them high usable in industrial applications for 5G and RF devices, IoT, portable audio and navigation devices, medical applications for patient monitoring systems, therapeutic and surgical equipment, and more.
Conclusion
The continuous advancement of mobile phones and wearable devices has spawned design challenges for connectivity product makers. Miniaturization has become a crucial linchpin to solve some space problems especially when PCB space is a premium. Each new generation of RF antenna modules and smartphones brings us closer to realizing the full potential of 5G performance. Molex is quick to harness these opportunities to deliver interconnect solutions that can address high data speed while delivering excellent SI performance and meeting demanding 25 GHz mmWave applications. Molex is raising the bar in signal stability, robust performance and fast assembly. Dedicated to providing innovative interconnect solutions to address evolving and emerging applications while enabling customers to enjoy new, enhanced functionality over reduced product size, Molex is a leading supplier of advanced 5G RF board-to-board connectors, bolstered by its legacy of innovation and collaboration with leading developers of RF antenna modules and mobile devices.