LSR Overmolding on Copper & Aluminum Busbars: A Revolutionary Upgrade in Insulation Protection

I. Industry Challenges in Copper/Aluminum Busbar Insulation

Copper and aluminum busbars are critical conductive components in power distribution systems, EV battery packs, energy storage systems, and telecom base stations. Traditional insulation methods - heat shrink tubing, insulating tape wrapping, and epoxy coating - face fundamental limitations in production efficiency, consistency, and long-term reliability.

II. LSR Overmolding Technology Breakthrough

Liquid Silicone Rubber (LSR) overmolding directly coats copper or aluminum busbars through precision injection molding, creating an integrated, zero-gap insulation layer. This technology surpasses traditional processes in both material properties and manufacturing methodology.

Material Advantages: LSR offers -50°C to 200°C continuous service temperature, ≥20kV/mm dielectric strength, UL94 V-0 flame retardancy, and 300%-700% elongation at break (vs 2%-5% for epoxy). Unlike heat shrink tubing, LSR maintains elastic sealing through thermal cycling without embrittlement.

Process Advantages: Fully automated injection molding with 30-90 second cycle time per part - 10-20x more efficient than manual wrapping. Computer-controlled process ensures coating thickness uniformity within ±0.1mm tolerance.

III. Performance Comparison (2mm Copper Busbar Example)

LSR overmolding outperforms alternatives across key metrics: temperature range (-50°C to 200°C vs -40°C to 125°C for heat shrink), IP68 waterproof sealing vs IP54-IP65, dielectric strength ≥20kV/mm, and peel strength ≥8N/mm on copper.

IV. Applications

EV Battery Packs: Copper-aluminum connectors between battery modules require reliable insulation under hundreds of amperes of current. LSR overmolding simultaneously meets CTI≥600V, electrolyte resistance (720h immersion), vibration resistance (ISO 16750-3), and UL94 V-0 flame retardancy.

Energy Storage Systems: LSR overmolding saves 30%+ space vs heat shrink tubing in dense busbar layouts, with no creepage risk.

Telecom & Data Centers: UPS power distribution busbars maintain ≥1000MΩ insulation resistance after 1000h at 85°C/85%RH - ten times better performance retention than traditional solutions.

V. Quality Assurance

AOI visual inspection (≥99.5% detection rate), CMM dimensional inspection (±0.1mm), dielectric test (2x rated voltage + 1000V, 1min no breakdown), insulation resistance (≥1000MΩ), air leak test (0.3MPa, 30s, ≤3mL/min), peel test (copper ≥8N/mm, aluminum ≥6N/mm), thermal shock (-40°C to 125°C, 500 cycles), salt spray (5% NaCl, 48h), UL94 V-0 flame test.

VI. Conclusion

LSR overmolding on copper/aluminum busbars is redefining insulation protection standards in power electronics. Contact us for sample testing and technical evaluation.