Detection of soldering induced damages on crystalline silicon solar modules fabricated by hot-air soldering method

Abstract

a b s t r a c tIn this study, electroluminescent (EL), eddy current (EC) technology, and IeV measurements were used to analyze the soldering-induced damages on crystalline silicon solar modules fabricated by hot-air soldering method. Experimental results reveal that the most common defects, in the order of occurrence frequency, are cracks, gridfinger interruption at busbar (GFIB), and floating solders. High thermal stress is the main cause for the cracks and GFIB, which mostly appear close to the region of silver paste. Floating solder is often observed in a soldering process using materials with high melting temperatures such as lead-free solders. Both GFIB and floating solder induce obvious power degradation. Although floating solder is not easily identified in an EL image, it can be detected by using the EC method. The tensile tests reveal that if more floating solders occur in a sample group, then these samples also show lower tensile strength.

Comparison of the 60Sn40Pb and 62Sn2Ag36Pb Solders for a PV Ribbon Joint in Photovoltaic Modules Using the Thermal Shock Test

“…We confirmed the diagonal cracks in the EL image, as shown in Figure 4a. Such diagonal cracks are characteristic of monocrystalline silicon wafers and anisotropic materials [16]. However, the internal cracks are inactive and do not influence the efficiency or changes in the EL images.…”

Research of the Energy Losses of Photovoltaic (PV) Modules after Hail Simulation Using a Newly-Created Testbed

“…Before and after the hail simulation, PV modules were photographed (using an electroluminescence camera) on the electroluminescent stand with an electric current (the current depended on the size of the PV modules; it can reach up to 4-5 A) supplied to the PV modules. Electroluminescent imaging is usually used to check for defects [54][55][56] because the intensity of radiation is proportional to the current density. The pictures taken helped detect any defects in the PV modules.…”

Methodology for Calculating the Damaged Surface and Its Relationship with Power Loss in Photovoltaic Modules by Electroluminescence Inspection for Corrective Maintenance

“…With the primary goal of executing more effective maintenance actions, there is a need for user-friendly tools that enable swift decision making. During the manufacturing of the PV modules, especially throughout the soldering processes, significant mechanical stresses are imparted onto the solar cells, leading to damage in the cells themselves, which could potentially impact production [ 3 ]. The damage produced during manufacturing has been the subject of study by various researchers over the last decade.…”