In this paper, a ball grid array（BGA） solder joint shearing experimental equipment is designed, and a supporting upper computer software to control the movement of the equipment is developed. Based on this equipment, the shear mechanical properties of BGA solder joints of two materials（SAC305 and Sn63Pb37） at fixed heights（60 μm）, different shear rates（0.1, 0.3, 0.5, 0.7 mm/s）, as well as shear mechanical properties at fixed shear rates（0.5 mm/s） and different shear heights（60, 80, 100, 120 μm） are studied. Experiments show that the shear strength of the solder joints of the two materials increases with the increasing of the shear rate under the condition of fixed shear height, and the shear strength of the solder joints of both materials decreases with the increasing of shear height under the condition of fixed shear rate. Experimental teaching through this equipment helps to cultivate students’ scientific thinking and improve students’ practical ability.

Integrated circuit (IC) X-ray wire bonding image inspections are crucial for ensuring the quality of packaged products. However, detecting defects in IC chips can be challenging due to the slow defect detection speed and the high energy consumption of the available models. In this paper, we propose a new convolutional neural network (CNN)-based framework for detecting wire bonding defects in IC chip images. This framework incorporates a Spatial Convolution Attention (SCA) module to integrate multi-scale features and assign adaptive weights to each feature source. We also designed a lightweight network, called the Light and Mobile Network (LMNet), using the SCA module to enhance the framework’s practicality in the industry. The experimental results demonstrate that the LMNet achieves a satisfactory balance between performance and consumption. Specifically, the network achieved a mean average precision (mAP50) of 99.2, with 1.5 giga floating-point operations (GFLOPs) and 108.7 frames per second (FPS), in wire bonding defect detection.

Nanofiber is a kind of high-performance material, which has great applications. Among many preparation methods, centrifugal electrospinning combines the advantages of electrospinning and centrifugal spinning, with high yield and a wide range of application. But its influencing factors are numerous, the process is still immature, and unable to meet the needs of industrialization. Here, we design a set of centrifugal electrospinning equipment and its process, and explore the influence of rotor form on fiber formation. First, the structure and working principle of experimental equipment of centrifugal electrospinning are introduced. Then, the influence of two factors, the rotor shape and rotor material, on space electric field is studied through theoretical and simulation analysis. Finally, based on the designed equipment, the effects of different rotor forms on the fibers preparation of centrifugal electrospinning are studied. The results show that the fiber diameter of centrifugal electrospinning is greatly affected by the form of the rotor. By changing the surface shape of the rotor and the rotor material, the diameter of the fiber can be controlled. Experiments show that the average fiber diameter of the gamma-shaped rotor is the smallest, and the fiber spun with ULTEM PEI 1010 material has the best overall performance.

In 3D packaging memory devices, solder joints are critical links between the chip and the printed circuit board (PCB). Under severe working conditions, cracks inevitably occur due to thermal shock. If cracks grow in the solder joint, the chip will be disconnected with the PCB, causing its function failure. In this paper, the reliability of solder joints under thermal shock are evaluated for 3D packaging memory devices by means of the SEM and finite element analysis. As microscopically studied by the SEM, it is found out that the main failure mechanism of solder joints in such test is the thermal fatigue failure of solder joints. Finite element analysis shows that cracks are caused by the accumulation of plastic work and creep strain. The initiation and growth of cracks are mainly influenced by the inelastic strain accumulation. The trends of cracks are influenced by the difference between the coefficient of thermal expansion (CTE) of epoxy resin and that of the chip.

With the development of science and technology, consumers’ requirements for various electronic devices present a trend of more diverse functions and thinner bodies. This makes integrated circuits mounted in electronic products and their packaging more vital to satisfying the above requirements. Ball grid array (BGA) packaging is widely used in the field of microelectronic manufacturing industries due to its multiple I/O volumes and excellent electric characteristics. However, due to environmental loads such as vibration and impact during its production and application, defects inevitably emerge in BGA solder joint defects, which will lead to the failure of electronic products. This article summarizes the state-of-the-art research on the factors, analysis methods, and models for the fatigue failure of BGA chips. After rigorous discussions concerning this research, some theoretical suggestions are provided for BGA packaging in reliability analysis and the establishment of evaluation standards.