As next-generation technologies such as information communication, new energy, and new materials continue to deeply integrate with the automotive industry, the “new four modernizations”—electrification, intelligence, connectivity, and sharing—are steering the industry’s development. Against this backdrop, the wire harness sector is poised to evolve in five key directions: lightweighting, high voltage, high-speed, platformization, and smart manufacturing.
Components of Automotive Wire Harnesses
- Lightweighting
1.1 Optimizing Architecture to Reduce Wire Harness Length
As the vehicle’s network architecture shifts from a traditional distributed structure to a centralized domain-based architecture, the length of wire harnesses has been reduced by 50% compared to traditional vehicles. This optimization not only lightens the weight of the wire harness but also lowers material costs and eases assembly.
1.2 Use of New Products like Aluminum and Copper-Clad Aluminum Alloy Wires
Aluminum wires, which are one-third the density of copper and have 64% of copper’s electrical conductivity, offer a cost-effective alternative. By upgrading wire specifications by one or two levels, the conductor portion can be lightened by 50%, and the overall wire cost reduced by 40%. Large-diameter aluminum wires are already widely used for power lines, while smaller-diameter copper-clad aluminum alloy wires can replace copper wires of the same gauge in low-voltage harness assemblies, reducing wire costs by 10%.
1.3 Miniaturization of Wires and Connectors
Signal wires can now use ultra-fine 0.22/0.13/0.08mm² wires, with the 0.22/0.13mm² wires already extensively used in joint ventures. Miniaturized terminals and connectors help reduce the overall volume and weight of the wire harness.
1.4 Research and Application of FFC Flexible Flat Cables
Flexible flat cables (FFC) are lightweight, bendable, and foldable, making them ideal for high-space-demand areas such as roof harnesses and low-voltage wiring in power battery packs.
1.5 Development and Application of Electronic Fuse Boxes
By replacing traditional fuses and relays with semiconductor chips, electronic fuse boxes reduce their volume by about 15% and weight by approximately 20%. These fuse boxes offer high reliability, programmability, and low-maintenance advantages.
Trends in Automotive Electrical Architecture
- High Voltage
2.1 Platformized Design of High Voltage Connectors
Electric vehicles (EVs) typically operate with high-voltage systems above 300V and high currents, necessitating improved insulation and safety measures for connectors. Key design elements for high-voltage connectors include temperature rise and derating curves, high-voltage interlock mechanisms, protection ratings, electromagnetic shielding, and material selection.
2.2 Surface-Mounted Connectors
Surface-mounted connectors are particularly advantageous in high-current applications. Their contact points are arranged linearly, and by increasing the contact width or using multiple contacts in parallel, contact resistance can be minimized.
2.3 High-Current Busbars
To meet the demands for rapid charging, busbars have become essential. They enable automated assembly and eliminate the need for processes like wire drawing, annealing, and twisting, which are typically required for cables.
2.4 Development of EMC Performance for High-Voltage Wire Harnesses
To address EMC (electromagnetic compatibility) concerns, high-voltage wire harnesses employ strategies such as grounding filters and shielding. High-voltage wires typically use double-layer shielding, and high-voltage connectors incorporate shielding rings or spring shields for enhanced performance.