Investigation of Gradient Curing on the Characteristics of Low Temperature Silver Paste

This research investigates the influence of the resin curing process on the electrical conductivity and soldering adhesion in low-temperature silver paste, used in heterojunction cells (HJT). Adjusting the dosage of high-temperature and low-temperature curing agents was carried out in this study to achieve a gradient curing profile, which is characterized using Differential Scanning Calorimetry (DSC). The results indicate that the gradient curing strategy enhances the compactness between silver particles after resin curing, thereby improving the electrical conductivity of the cured layer. Moreover, gradient curing improves the adhesive bond between the cured layer and the battery sheet, thus increasing the welding drawing force. The optimized silver paste, with a resistivity of 5.7 μΩ·cm and a welding drawing force of 2.0 N, meets the stringent requirements of industrial production for these two parameters.