Solar ribbons are made of copper and work like threads joining the individual solar cells and collecting and transmitting current from these. Mengjiao Liang, the Manager of Overseas Market for Suzhou YourBuddy New-type Materials Co., Ltd., discussed the application of ultra-fine low-temperature ribbons in ZBB modules while speaking on day 2 of the 4-day TaiyangNews High Efficiency Solar Technologies 2024 Conference.
For such modules, she recommended using a ribbon with a diameter of 0.18mm and 0.20mm with low-temperature alloys as it offers better yield and high tensile strengths, adjustable solder composition that can be customized, and has excellent wettability and solderability.
Liang pointed out that the low-temperature ribbon used in HJT technology primarily contains bismuth which has questionable reliability, but is about 35 times less expensive than indium. Unlike indium, which is sparsely available, China has large deposits of bismuth, accounting for about 240,000 tons out of close to 370,000 tons of the world’s total reserves. According to Liang, in the short term, bismuth production can meet the demand for ZBB modules.
To increase the corrosion resistance of ribbons, YourBuddy recommends adding some rare earth elements like phosphorus, gallium, germanium, and nickel.
At present, the round wire shaped ultra-fine low-temperature ribbon is the most popular, but it will be a triangular ribbon that’s expected to come into wider use since the latter has a thinner diameter, lower soldering melting point, and higher reflectivity, according to Liang.
YourBuddy offers 2 kinds of triangular ribbons, namely ø0.25 mm segmented, and ø0.1mm ultrafine continuous triangular ribbon.
For more presentation videos and conference summaries for all 4 days of the TaiyangNews High Efficiency Solar Technologies 2024 Conference, click here for days 1 and 2, and here for days 3 and 4.