The Science Behind Small: Unlocking Performance in Miniaturized Rugged Connectors

The continuous miniaturization of electronic devices demands increasingly smaller connectors. Traditional materials reach their limits when used in miniaturized components, where the ability to maintain strength and other performance attributes while reducing weight and size becomes critical. To overcome these challenges and maintain performance, the future of connector miniaturization relies on advancements in material science.

How can innovative materials, particularly advanced engineering plastics, support the design requirement to shrink connectors while simultaneously ensuring their successful performance?

Miniaturization presents significant challenges in material selection for connector design and manufacturing. Unlike larger connectors, miniaturized versions prioritize weight reduction and minimization of dimensional footprints. While affordable and versatile, traditional materials used for connector housings often lose significant strength when utilized for thin wall sections. Thin wall sections can also create high stress concentrations risking failure under load. Other materials that have high levels of strength, such as metals, may not be suitable replacements for these traditional engineering plastics for many reasons.  Factors to consider include the electrical insulation requirements, form factors, impact/durability, weight, cost and/or manufacturability requirements of the product.

The solution lies in utilizing advanced insulating materials engineered specifically for miniaturization. High-performance polymers (HPPs) like polyphthalamide (PPA), liquid crystal polymer (LCP) and other specially formulated polymers offer both high strength and superior dimensional stability while maintaining a lightweight profile. Such characteristics make HPPs the perfect choice for designs requiring miniaturized connectors in applications including V2X, 5G, networking and IoT.

Advanced materials incorporate nanoparticles throughout the polymer matrix, significantly enhancing stiffness and strength without adding substantial weight. Nanocomposites show promise in allowing material scientists to achieve the desired ruggedness in miniaturized connectors for applications such as industrial automation and AI solutions.

By leveraging advanced materials like HPPs and nanocomposites, material scientists can address weight limitations and ensure strength in connectors designed to fit into tight spaces. These materials also allow improved thermal management in small areas. However, with these enhancements come new challenges in balancing performance, cost and commercial scalability.

Shrinking connector size exposes the limitations of traditional materials. When used in miniature scale connector structures, these materials’ bulk properties become misleading due to the influences of large surface area-to-volume ratios and compositional variations/filler dimensions of a similar scale to the connector structure itself. While these materials perform well in larger forms, they often exhibit insufficiency when miniaturized. Consequently, HPPs specifically formulated for strength and durability with minimized anisotropy at small scales become essential.

HPPs address the challenges of miniaturization through a combination of factors. Their lower melt viscosity — lower than traditional polymers — allows enhanced flowability, enabling them to fill intricate molds needed for complex miniaturized connector geometries while minimizing deformation. Unlike conventional polymers that weaken in thin sections, HPPs maintain a high strength-to-weight ratio even at reduced dimensions. This is achieved by incorporating innovative fillers and chemistries within the HPP matrix, creating high dimensional accuracy and stability. 

The challenges of miniaturization extend beyond achieving desired mechanical strength. Connectors designed for miniaturized applications must also meet specific requirements based on their applications.

Flame Retardancy: Miniaturized connectors may also be required to operate in environments with a high potential for becoming fire hazards. HPPs can be formulated to be flame-retardant by incorporating specific additives that interfere with combustion by absorbing heat, releasing non-combustible gases or forming a protective char layer.

Chemical Resistance: Exposure to harsh chemicals can significantly degrade a connector's performance. HPPs can be formulated to resist specific chemicals based on the application. However, some chemically resistant polymers may not possess the desired flow properties or may introduce brittle characteristics. Stress can significantly affect the chemical resistance of plastic materials. Design engineers must carefully consider these qualifications to determine the right materials in combination with design features for each application.

High Quality: Even the smallest impurities — like trace metallic contaminants or unwanted byproducts — can significantly affect polymers, increasing the likelihood of cracks or premature failure. HPP formulations prioritize high-quality starting materials and rigorous processing techniques and ensure consistent performance and reliability.

Achieving optimal performance requires a careful balance. Intricate miniaturized connector geometries and stringent requirements such as flame retardance and chemical resistance pose constant challenges to existing materials. Material scientists continuously develop and refine HPP formulations to meet these complex and ever-changing demands.

3D printing offers exciting possibilities for rapidly prototyping parts. During the development stage, 3D printing empowers engineers with speed and affordability, enabling rapid iterations. This allows for quick form and fit evaluations before committing to final, high-performance materials and costly manufacturing processes.

However, 3D printing has significant limitations when employed beyond prototyping. The dimensional resolution of current 3D printing technologies is insufficient for creating highly miniaturized parts for final production. With tolerances at the micron level, the 3D printing process and associated materials currently fall short of achieving optimal mechanical performance and electrical functionality. If high-resolution printing techniques advance, 3D printing could become a valuable prototyping tool as well as a viable means of manufacturing functional product parts in the future.

Understanding structure-property relationships is vital for selecting the optimal material. This knowledge allows engineers to identify materials that balance strength, weight, functionality and durability.

Replacing metals with advanced plastics offers opportunities for lightweighting connectors. However, traditional plastics often lack the conductivity, strength and durability of metals. Incorporating novel materials like graphene and carbon nanotubes (CNTs) in plastics could provide superior strength-to-weight ratios, thereby enabling innovative form factors and broadening the opportunities to substitute for metals

Artificial intelligence (AI) and machine learning (ML) hold considerable potential for material selection and connector design and manufacturing. These technologies can analyze data, uncover interdisciplinary insights, automate processes, provide real-time monitoring, predict outcomes and enhance decision-making, leading to the faster development of high-performing connectors from end to end.

Digital twins create virtual replicas of physical connectors and enable critical data collection. Engineers can establish a real-time feedback loop that informs future design iterations by continuously feeding real-world testing data or sensor readings back into the digital twin. This virtual testing ground accelerates development cycles, optimizes performance and enhances reliability for miniaturized connectors.

Advancements in material science remain key to developing rugged connectors with increasingly smaller footprints.

Material selection presents significant opportunities in exploring transformative solutions that help companies achieve their environmental stewardship goals. As customers increasingly seek solutions that help address environmental needs, miniaturized connector manufacturing is adopting innovative methods to minimize environmental impact by using fewer resources.

Bioplastics offer a promising path for sustainable material selection. These materials use renewable bio-based feedstocks like cornstarch, cellulose and castor oil as an alternative to traditional non-renewable feedstocks used in plastic production. Additionally, mechanical and chemical recycling technologies can repurpose existing plastics, conserving virgin resources and minimizing environmental impact. 

Those involved in the entire miniaturized connector design and manufacturing lifecycle are best advised to actively monitor and explore the development of sustainable materials and technologies. Further, regional regulations play a significant role in driving renewable material adoption.

By taking a comprehensive approach to renewable materials, stakeholders can make informed decisions that balance connector performance with environmental impact.

Material science is the cornerstone of enabling rugged miniaturized connectors. As a leader in high-performance connectivity solutions, Molex focuses on materials and materials processing innovation, material selection/application engineering and the materials testing and data required to enable the optimal product digital twin. To explore the advancements shaping the future of connectors, download our Rugged Miniaturization Report.