The influence of heat treatment on properties of lead-free solders

The article is focused on the analysis of degradation of properties of two eutectic lead-free solders SnCu0.7 and SnAg3.5Cu0.7. The microstructures of the intermetallic compound (IMC) layers at the copper substrate - solder interface were examined before and after heat treatment at 150°C for 50, 200, 500 and 1000 hours. The thickness of IMC layers of the Cu6Sn5 phase was growing with the increasing time of annealing and shown the typical scallops. For the heat treatment times of 200 hours and longer, the Cu3Sn IMC layers located near the Cu substrate were also observed. The experiments showed there is a link between the thickness of IMC layers and decrease of the shear strength of solder joints. In general, the joints made of the ternary solder showed higher shear strength before and after heat treatment in comparison to joints from solder SnCu0.7

The influence of heat treatment on properties of lead-free solders

The article is focused on the analysis of degradation of properties of two eutectic lead-free solders SnCu0.7 and SnAg3.5Cu0.7. The microstructures of the intermetallic compound (IMC) layers at the copper substrate - solder interface were examined before and after heat treatment at 150°C for 50, 200, 500 and 1000 hours. The thickness of IMC layers of the Cu6Sn5 phase was growing with the increasing time of annealing and shown the typical scallops. For the heat treatment times of 200 hours and longer, the Cu3Sn IMC layers located near the Cu substrate were also observed. The experiments showed there is a link between the thickness of IMC layers and decrease of the shear strength of solder joints. In general, the joints made of the ternary solder showed higher shear strength before and after heat treatment in comparison to joints from solder SnCu0.7

Increase of the Automotive Power Transistor Modules Manufacture Reliability Using Ai Detecting System for Soldering Splashes

This study discusses the automated visual inspection of electronic boards used in the mass production of power electronics equipment. Soldering splashes, produced during the necessary manufacturing stages, can affect the hybrid power semiconductor modules' quality, specifications and lifespan. Splashes from soldering may appear in some electronic boards areas when they may cause decreasing of quality of these boards and need to be removed. Image analysis algorithms are used to search for such areas. The automated inspection is based on neural network YOLO. The images of electronic boards, acquired by authors in SEMIKRON Slovakia company, were used as training, testing and validation dataset for the YOLO network. The custom recording system was designed to acquire those images. The implementation of this method may increase the object search success and then thereby increase the overall quality of module production