How many types of raw materials are there for the conductive busbars?

Key Considerations When Choosing Busbar Material Current Capacity: Copper outperforms Al for high-current density. Weight: Aluminum is preferred in aerospace/mobility. Corrosion Resistance: Al suits humid environments; Cu requires plating. Cost: Aluminum is ∼1/3 the price of copper (by weight). Thermal Needs: Composites (Cu-Mo) for high-power cooling.

 

Author: Robby

Conductive busbars are manufactured from various raw materials, each selected for specific electrical, thermal, mechanical, and cost requirements. Here’s a detailed breakdown of the types of raw materials used, along with their properties and applications:

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1. Primary Conductive Metals (Most Common)

(A) Copper (Cu)

• Properties:

  • Highest electrical conductivity (∼100% IACS)* after silver.

  • Excellent thermal conductivity (∼385 W/m·K).

  • Good mechanical strength and ductility.

  • Prone to oxidation (requires plating: Sn, Ag, Ni).

• Grades:

  • C11000 (ETP Copper): 99.9% pure, standard for electrical busbars.

  • C10100 (Oxygen-Free Copper): Higher purity for critical applications.

• Applications:

  • Power distribution, switchgear, EV battery interconnects.

(B) Aluminum (Al)

• Properties:

  • Lower conductivity (∼61% IACS) but lightweight (1/3 the weight of Cu).

  • Naturally corrosion-resistant (forms Al₂O₃ oxide layer).

  • Lower cost than copper.

• Grades:

  • 6061-T6: High strength, used in structural busbars.

  • 1350-H19: Soft, high-conductivity alloy.

• Applications:

  • Overhead power lines, renewable energy systems, lightweight enclosures.

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2. Alternative Conductive Materials

(C) Copper-Clad Aluminum (CCA)

• Structure: Aluminum core with copper outer layer.

• Pros:

  • Lighter/cheaper than pure Cu, better conductivity than pure Al.

• Cons:

  • Risk of galvanic corrosion at joints.

• Applications:

  • Cost-sensitive busbars where weight matters (e.g., LED lighting).

(D) Silver (Ag)

• Properties:

  • Best conductivity (∼105% IACS), but expensive.

  • Used as a plating layer (not typically solid busbars).

• Applications:

  • High-frequency/RF busbars, aerospace.

(E) Brass (Cu-Zn Alloy)

• Properties:

  • Lower conductivity (∼28% IACS) but high machinability.

• Applications:

  • Low-current busbars, decorative electrical components.

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3. Composite & Hybrid Materials

(F) Copper-Molybdenum (Cu-Mo) or Copper-Graphite (Cu-C)

• Properties:

  • Tailored thermal expansion (CTE) for semiconductor cooling.

  • High thermal conductivity with low expansion.

• Applications:

  • Power electronics (IGBT modules), laser diode mounts.

(G) Metal-Matrix Composites (e.g., Al-SiC)

• Properties:

  • Lightweight with enhanced stiffness/thermal performance.

• Applications:

  • Aerospace, high-vibration environments.

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4. Non-Metallic Conductors (Emerging)

(H) Conductive Polymers (PEDOT, Graphene-Enhanced)

• Properties:

  • Lightweight, corrosion-proof, but lower conductivity.

• Applications:

  • Flexible busbars, wearable electronics.

(I) Superconductors (e.g., YBCO)

• Properties:

  • Zero resistance below critical temperature (expensive, complex cooling).

• Applications:

  • Experimental high-power systems (fusion reactors, maglev).

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5. Structural & Coating Materials

(J) Steel (Plated with Cu, Sn, or Ni)

• Properties:

  • High strength but poor conductivity (plating improves surface conduction).

• Applications:

  • Grounding busbars, structural supports.

(K) Insulation/Jacketing Materials

• Examples:

  • Epoxy Coatings: For corrosion resistance.

  • Heat-Shrink Sleeves: For insulation in high-voltage busbars.

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Material Selection Guide

Material	Conductivity (% IACS)	Key Advantage	Limitation	Typical Use Case
Copper (C11000)	100%	Best conductivity	Expensive, heavy	High-current busbars
Aluminum (1350)	61%	Lightweight, cheap	Lower conductivity	Power transmission
Copper-Clad Al	60–80%*	Cost/weight balance	Galvanic corrosion risk	Budget busbars
Brass	28%	Easy to machine	Poor conductivity	Decorative/low-power
Cu-Mo Composite	50–90%	Thermal management	Very costly	Power electronics cooling

(IACS = International Annealed Copper Standard)
(CCA conductivity varies with Cu layer thickness)*

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Key Considerations When Choosing Busbar Material

1. Current Capacity: Copper outperforms Al for high-current density.

2. Weight: Aluminum is preferred in aerospace/mobility.

3. Corrosion Resistance: Al suits humid environments; Cu requires plating.

4. Cost: Aluminum is ∼1/3 the price of copper (by weight).

5. Thermal Needs: Composites (Cu-Mo) for high-power cooling.

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Conclusion

The main raw materials for busbars are copper, aluminum, and their alloys/composites, with niche uses for brass, steel, and advanced materials like superconductors. Selection depends on:

• Electrical needs (current density, resistance).

• Mechanical requirements (weight, strength).

• Environmental factors (corrosion, temperature).

• Budget constraints.

For example:

• EV Battery Busbars: High-purity copper (plated with Sn/Ni).

• Solar Farm Busbars: Aluminum (cost-effective for large spans).

• Aircraft Power Distribution: Aluminum or Cu-clad Al (lightweight).