Round PV Ribbon

Round PV Ribbon for MBB, SMBB and 0BB Solar Cell Interconnection

Round PV Ribbon is a high-precision circular conductor engineered for advanced solar cell interconnection. By replacing traditional flat ribbon, the round geometry minimizes cell-surface shading and optimizes light reflection into active areas. Designed specifically for MBB, SMBB, and 0BB module architectures, it enables higher packing density, reduced resistance, and superior stringing stability. Available in various fine-diameter options, solder alloys, and spooling configurations, this product supports seamless integration into high-efficiency N-type, TOPCon, and HJT manufacturing lines.

Round PV Ribbon Specifications

Parameter	SMBB Round Wire	0BB Round Wire
Cross-section	Circular	Circular
Base Material	TU1 Oxygen-Free Copper	TU1 Oxygen-Free Copper
Copper Purity	≥99.97%	≥99.97%
Wire Diameter	0.23 mm – 0.26 mm	≤0.22 mm
Yield Strength	≤70 MPa (Ø >0.26 mm) / ≤80 MPa (Ø ≤0.25 mm)	≤70 MPa (Ø >0.26 mm) / ≤80 MPa (Ø ≤0.25 mm)
Elongation	≥20%	≥20%
Solder Coating	Sn-Pb, Sn-Pb-Ag, Lead-Free Alloys	Sn-Pb, Sn-Pb-Ag, Lead-Free Alloys
Spool Specification	Customized / DIN / PT Series	Customized / DIN / PT Series
Target Application	SMBB / High-Density Interconnection	0BB / Busbar-less Cell Interconnection

Product Configurations

SMBB Round Wire (0.23–0.26 mm)

Engineered for multi-busbar modules to maintain optimal electrical current transport while decreasing cell shadowing.

0BB Round Wire (≤0.22 mm)

Ultra-fine conductor optimized for busbar-less cell layouts, reducing silver paste consumption and footprint coverage.

Key Advantages of Round Geometry

Reduced Surface Shading

Circular profile significantly lowers the physical shading area compared to flat ribbon formats.

Enhanced Light Capture

Off-angle incident light reflects off the rounded sides back onto the cell glass, raising overall module power output.

High-Density Compatibility

Supports multi-wire layouts that split current flow, lowering internal resistance losses across the solar module.

Application Matrix by Cell Architecture

Architecture	Recommended Ribbon	Technical Focus
MBB Modules	Round PV Ribbon	Diameter precision, consistent solderability, balanced mechanical properties
SMBB Modules	SMBB Round Wire	Fine wire diameter, high concentricity, low yield strength
0BB Modules	0BB Round Wire	Ultra-fine gauge, stringing stability, delicate contact compatibility
N-Type (TOPCon/HJT)	SMBB / 0BB Round Wire	Low thermal stress, specialized solder compatibility, oxidation control

Substrate and Coating Properties

TU1 Pure Copper Core

Features high conductivity copper (≥99.97% purity) to ensure minimal electrical resistance and consistent ductility.

Custom Solder Coating

Formulated to match specific soldering temperatures, pad metallization, and high-speed stringer settings.

Mechanical And Dimensional Control

Diameter Tolerance: Maintained within strict limits to ensure stable contact pressure and predictable line resistance.

Yield Strength Control: Kept low (≤70–80 MPa) to prevent cell micro-cracking during automated high-speed stringing operations.

High Elongation: Guaranteed at ≥20% to absorb thermal expansion stresses during thermal cycling and module operation.

Concentricity: Precise coating centering prevents uneven heat distribution during soldering, reducing thermal stress on cells.

Manufacturing Workflow

Substrate Preparation: High-purity TU1 copper rod is selected and prepared for precise cold drawing.

Precision Wire Forming: Multi-pass drawing dies produce uniform circular cross-sections to exact diameter requirements.

Controlled Annealing: In-line thermal treatment achieves soft mechanical properties required to prevent cell stress.

Hot-Dip Tinning: Continuous solder coating process applies exact alloy layers with smooth surface uniformity.

In-Line Inspection: Laser sensors constantly measure diameter, concentricity, and surface smoothness during production.

Precision Winding: Finished ribbon is wound evenly onto spools with controlled tension to prevent tangling during high-speed pay-off.

Quality Inspection Program

Raw Material Verification

Testing chemical purity of copper and checking incoming wire dimensions.

In-Process Monitoring

Real-time tracking of outer diameter, solder coating thickness, and geometric concentricity.

Finished Goods Testing

Mechanical yield strength, elongation checks, solderability tests, and surface visual inspection.

Documentation

Detailed test certificates and batch verification data provided upon request.

Customization and Technical Deliverables

Diameter Customization

Tailored diameter specifications to fit distinct stringer machinery and pad dimensions.

Alloy Formulation

Custom lead-bearing or lead-free solder alloy compositions matching customer melting point needs.

Spool Packaging

Customized spool sizes and pay-off tension setups engineered for seamless high-speed production integration.

Technical Documentation

Complete product specifications, material data sheets, mechanical test charts, and batch trace reports supplied.

Packaging, Handling and Storage

Protective Packaging

Sealed inner plastic bags with desiccant, packed in sturdy shock-resistant outer cartons or wooden boxes.

Storage Environment

Keep indoors in a clean, dry, ventilated area with relative humidity below 60%.

Handling Precautions

Protect from exposure to moisture, acidic fumes, and airborne chemical contaminants.

FAQ

Q: What is the core purpose of Round PV Ribbon?

A: It serves as the electrical interconnect between solar cells, reducing surface coverage and improving light reflection in MBB, SMBB, and 0BB modules.

Q: What diameters are available for solar cell stringing?

A: Standard SMBB configurations range from 0.23 mm to 0.26 mm, while 0BB layouts typically utilize ultra-fine wires of ≤0.22 mm.

Q: Which copper substrate material is used?

A: High-purity TU1 oxygen-free copper with a purity level of ≥99.97% is used to guarantee high electrical conductivity and ductility.

Q: Can solder coating composition be tailored?

A: Yes, alloy composition and thickness are fully adjustable based on customer stringing temperatures and cell metallization requirements.

Q: How does round ribbon prevent cell micro-cracks?

A: Low yield strength (≤70–80 MPa) and high elongation (≥20%) ensure soft material behavior that absorbs mechanical stress during soldering.

Q: What details are required to receive a technical quote?

A: Specify required diameter, module architecture (SMBB or 0BB), solder alloy type, spool preference, target stringer speed, and annual volume.

Request a Round PV Ribbon Specification

Submit your target wire diameter, solder coating alloy, cell architecture, and estimated order quantities to receive detailed technical data sheets and custom quotations.

As one of the leading round pv ribbon manufacturers and suppliers in China, we warmly welcome you to buy advanced round pv ribbon made in China here from our factory. All customized products are with high quality and competitive price. Contact us for quotation.