Effect of Nickel-plating on Laser Welding of Aluminum Packages for Microwave module

The effect of Nickel-plating on laser welding process of aluminum packages were studied in this paper. The laser welding of nickel -plating aluminum alloy was characterized by analyzing different welding parameters and different types of nickel-plated. Then by X-ray fluorescence thickness tester, optical microscope, scanning electron microscope, micro-section and micro-hardness, the weld morphology of nickel-plated aluminum alloy packages and the change of micro-hardness from the weld to the matrix were analyzed. The results show that, under appropriate welding parameters, nickel-plated aluminum packages could achieve laser welding. Different types of nickel plating was different for the effect of laser welding, electroplated nickel aminosulfamate and electroless NiP (less than 10%P) were smaller effects of laser welding and its laser welding was feasible. The electroless NiP (greater than 10%P) was easy to weld cracks, holes and other defects, affecting the sealing performance of aluminum package. Metallographic analysis also showed that the weld penetration of nickel-plated aluminum was greater than 0.5mm and the microstructure of its weld was compact and no internal cracks and other defects, with microstructure between the weld and the matrix the changing from the fine grains gradually into columnar grain. The micro-hardness results showed that the hardness became smaller along the direction of the heat-affected zone, indicating that the nickel element on its weld played the role of enhancement. At the same time, the reliability of validation results also show that both nickel and electroless nickel plating samples at temperature and humidity and mechanical stress, the sealing performance did not change, you can ensure reliability.