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Photovoltaic Ribbon Sunwire

Sunwire photovoltaic ribbon

Sunwire® is a copper-based flat ribbon used to connect silicon cells electrically and  to carry out current in crystalline silicon and thin-film photovoltaic modules.

Extra soft Sunwire® reduces cell breakages and reduces electrical resistance in modules. Combined with consistent quality, excellent spooling and straightness, Sunwire improves customers' manufacturing process and final product.

Sunwire is also an excellent choice for thin film modules.



Sunwire is rolled from round wire to high precision, annealed to extra soft, plated all-over in hot-dip-tinning process and precision level-wound on returnable spools. All standard dimensions, plating alloys and spool sizes are available.

The latest annealing and plating technology in Sunwire products is completely chemical-free and compatible with new lead-free soldering alloys and saves energy. It was developed to help our customers to improve their production yield and product performance.


Sunwire benefits

Smaller width

  • to avoid sacrificing cell yield
  • to enable 4-6 busbar cell solutions

Softer material

  • to avoid causing stress in the soldering process
  • to enable usage of thinner wafers
  • to reduce electrical resistance

Straighter material

  • to get out the full power of the module
  • usable also in large thin-film applications

Tin coating on every surface




Crystalline silicon panels Ongoing development of both multicrystalline and monocrystalline silicon cells requires continuous improvements in the wire. We are developing new products to meet the most stringent technological and market demands for all these applications.
Thin-film panels With the growth of thin-film solar panel markets, there are new requirements for both the wire and the connections between the wire and the thin-film module. Whether it is amourphous or ‘micromorph’ (microcrystalline / amourphous) silicon. CdTe or CIGS thin-films, we can provide the right solution for the module manufacturers.



Luvata is a member of:

Member of SolarPower Europe        Member of the Asian Photovoltaic Industry Association


We work in constant cooperation with our customers and top universities to improve our products and processes. We are the partner of choice for you.

The Sunwire® Evolution - passion for improvements

The continuous advancement of our photovoltaic ribbon, branded Sunwire, begins by listening to the new challenges facing PV module manufacturers. The incremental improvements made to Sunwire stem from the need for higher productivity in module manufacturing and improved efficiency of the module. Luvata's passion for finding the answers to these new challenges - this is Sunwire’s evolution.

Sunwire evolution

Sunwire® ES

With a high-purity oxygen-free copper core base, Sunwire ES offers exceptional electrical conductivity combined with guaranteed elongation and yield strength.  These enhanced mechanical properties reduce cell breakage rates and improve the productivity.

Sunwire® Deco

For architects who want to incorporate solar modules into their designs, but refuse to forego aesthetics, Luvata offers Sunwire Deco in various colours that don’t distract from the beauty of their designs.

Sunwire spools

Sunwire spools are getting bigger and bigger. Sunwire’s fully-automated spooling process ensure that its winding is consistent from one spool to the next, resulting in reliable and predictable de-spooling. This means less downtime and higher production output for module manufacturers.

Sunwire manufacturing locations

From one Sunwire manufacturing facility to four, today Luvata manufactures Sunwire in Pori, Finland; Pasir Gudang, Malaysia; Appleton, Wisconsin USA; and Suzhou, China. Along with local service and technical support, this global manufacturing network benefits PV module manufacturers by bringing the latest developments and innovations to them.


Luvata evolution


Sunwire’s evolution is the persistent passion in bringing the answers to the many challenges facing PV module manufacturers.  From a product that made the automated mass-production of photovoltaic solar panels possible, Sunwire continues to bring notable leaps forward in the evolution of photovoltaic ribbon.

Re-usable packaging

Luvata uses only recyclable packaging materials. For Sunwire deliveries, we use re-usable packaging, which enables customers to pack the empty spools into the very same package ensuring the optimal space utilisation, low damage ratio and high re-usability of spools.



Rolled from round wire  
Thickness (mm) 0,080-0,600 (Tolerance +/- 0,007)
Width (mm) 0,300-6,000 (Tolerance +/- 0,08)


Platings (hot dipped)*

Lead free Sn100; SnAgCu 96,5/3,0/0,5
Leaded SnPbAg 62/36/2; SnPb 63/37;
SnPb 60/40
Low temperature Bi-containing lead-free solder alloys
Plating composition and thickness 4-50 μm +/- 3 μm each side


Melting temperatures of different coating alloys

SnPbAg 62/36/2 179 °C
SnPb 63/37 183 °C
SnPb 60/40 183/190 °C
Sn 100 232 °C
SnAg Cu96,5/3,0/0,5 217/220 °C
Low temperature  
SnBiAg 60/38/2 139-170 °C


Base Materials

Cu-OF1 CW007A (acc. EN13602) CDA 102 Electrical Conductivity 101 103% IACS
Resistivity ≤ 1.72 x 10-8 Ωm


Mechanical Properties

Available Yield Strengths Rp0.2 <50-140 N/mm2
Elongation at fracture >25 %
Camber  <6 mm/m measured from the center of the spool


Spool & Disc Dimensions* (mm)

Spool type d1 d2 d3 L1 L2 Approx. winding volume in kg
10-S 152 100,5 16,1 121,5 101 5
K 160 160 100 22 160 128 8
HKV 160 160 90 22 160 85 8
HKV 200 200 112 22 200 106 15
SD 300 K 300  212 51,5 103  91 15-18



65 mm - 630 mm

*Also according to customer specifications

Sunwire Calculator

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Sunwire News

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