Why Choose SUNKEAN's Copper to Aluminum Cable Connecting Solution?

On June 11, the 18th SNEC PV+ International Solar Photovoltaic Exhibition (2025) commenced at the Shanghai National Exhibition and Convention Center. Attention focused on Booth A680 in Hall 6.1H, where SUNKEAN Cables (Wuxi) Co., Ltd. occupied a nearly 200-square-meter exhibition space, offering visitors an optimal viewing experience. In terms of presentation, SUNKEAN not only continued its tradition of displaying a complete range of cable product specifications and diverse application scenarios but also specially featured a hands-on operation station and a large-screen presentation area at this year's exhibition. Through innovative hands-on crimping experiences and the global bilingual premiere of its copper-to-aluminum connection solution, SUNKEAN captured significant attention from international attendees.

At the event, TÜV Rheinland and TÜV SÜD simultaneously conducted a certification ceremony for SUNKEAN's new products, authoritatively validating the reliability of SUNKEAN's copper-to-aluminum solution through these leading industry testing institutions. Concurrently, SUNKEAN stood out in two official SNEC awards, winning the APVIA Asia Solar Award and the SNEC Top 10 Highlights “Megawatt-Level Emerald Award” for outstanding products and technologies. Follow this article to explore how SUNKEAN's copper-to-aluminum solution delivers tangible improvements to PV power stations—from internal craftsmanship to external design.

The copper-to-aluminum solution reduces costs by 58% compared to all-copper systems, potentially saving over ¥20 million (approx. $2.75 million USD) per 1GW power station. SUNKEAN's solution thrives in the competitive energy market primarily due to two core components: the SK-TC Copper-Aluminum Transition Harness and the SK4A Aluminum Connector. Addressing industry pain points such as weak welding processes and risks of oxidation/breakage in PV connection systems, SUNKEAN leveraged its R&D expertise to implement a dual strategy: “structural optimization” + “production process refinement”. This approach advances the “aluminum-for-copper” transition through standards exceeding industry testing requirements.

First, SUNKEAN's SK-TC Copper-Aluminum Transition Harness adopts an innovative “copper + aluminum + copper” structure: copper conductor cables at both ends, an aluminum conductor cable in the middle, and plastic housings connecting the copper and aluminum sections. This product supports high currents of 46/55/70A, demonstrating stable current-temperature rise curves in testing to ensure reliable power transmission. The aluminum segment uses certified 2PfG 2642 1500V and 2PfG 2954 2000V aluminum conductor cables—replacing copper to significantly reduce procurement and logistics costs. To minimize installation complexity, both copper ends (male/female connectors) of the SK-TC harness are pre-crimped and pre-assembled. Customers only need to perform simple crimping on the aluminum cable ends during on-site installation.

Second, the housing and crown spring materials of SUNKEAN's SK4A Aluminum Connector match industry-leading brands. The PA66 housing delivers exceptional mechanical strength, maintaining high rigidity even under rigorous temperature-rise tests. The crown spring uses imported beryllium copper, processed with fully automated servo riveting technology, achieving ultra-low contact resistance (≤0.3mΩ). The latch spring features six laser-welded points, ensuring structural precision, eliminating rotation/loosening risks, and excelling in complex environments.

First, the SK4A Copper-to-Aluminum Terminal abandons traditional fusion welding for advanced friction welding. This precision solid-state bonding technology uses high-speed friction heat and axial pressure to generate plastic flow between copper and aluminum, achieving atomic-level fusion. SUNKEAN's friction welding overcomes challenges posed by differing copper/aluminum melting points and expansion coefficients. Compared to fusion welding, it operates at lower temperatures, reducing thermal damage to cables and guaranteeing <0.5% conductivity degradation over 25 years. The process also enhances bond strength by 1.5× above national standards, drastically minimizing brittle fracture risks. Post-production, terminals undergo pull-force tests and impact resistance verification to ensure stability.

Secondly, SUNKEAN has given the SK4A copper-to-aluminum connection terminal more than 30 processes and a three-layer structure, creatively constructing a gradient composite protection system. The coatings from the inside to the outside are a patented diffusion layer, a chemical nickel plating layer, and a hot-dip tin anti-oxidation layer, which inhibit 90% of ion migration from the base layer to the surface, resist acid and alkali erosion in extreme environments, hydrogen sulfide corrosion, and effectively reduce contact resistance. The specially designed electroplating holes in the upper part of the terminal play an important role in maintaining uniform plating. In order to verify the corrosion resistance of the terminal, SUNKEAN conducted a 96H salt spray test. In a 5% concentration of salt water solution, the product contact area maintained an excellent zero corrosion performance.