Does infrared soldering affect interconnection of silicon heterojunction (SHJ) solar cells?

ABSTRACT: Interconnection of silicon heterojunction (SHJ) solar cells by soldering is challenging due to the temperature sensitivity of the passivation layers. Within our study, we evaluate solder joints on SHJ solar cells interconnected by infrared (IR) soldering.

Did a production error lead to cold solder joints?

In the run-up to pv magazine ’s quality roundtable at Intersolar Europe, we look at a case where a production error resulted in cold solder joints in 5% of the solar modules across a 50 MW project portfolio.

What are cold solder joints?

Cold solder joints occur when the temperature during the soldering process is not high enough, and they are difficult to see with the naked eye. “It turned out to be important that we had agreed in advance with the manufacturer on the criteria for replacing modules,” says CEA's Director of Technology and Quality, George Touloupas.

Do heterojunction solar cells interconnect by soldering?

2.1 Heterojunction solar cells To study the interconnection process on SHJ solar cells by soldering, we use bifacial monocrystalline SHJ cells (156.75 × 156.75 mm2) of our project partner Meyer Burger (Germany) GmbH. The cells are pre-processed on

Why do we use infrared soldering at 240 °C?

Infrared soldering at ~240 °C enables the use of industrially established equipment and to forgo alternative interconnection processes. The formation of well adherent void-free solder joints allows string handling, module integration and a detailed analysis of the solder joints, as shown in this study.

How are solder joints analyzed?

The microstructure and quality of the solder joints is analyzed using SEM and EDX. Additionally, 3D scans using X-ray micro-computed tomography (μCT) reveal the inner structure and the microstructural quality of the solder bonds.