As a critical device of power electronics, the health status and residual life of the insulated gate bipolar transistor (IGBT), as well as its high-efficiency assessment should be concerned. High-efficiency assessment methods can provide dangerous warning for transportation equipment to avoid catastrophic accidents. This article focuses on the IGBT solder layer failure. We use the finite element simulation combined with the small current junction temperature measurement method to obtain the relationship between the internal structure degradation of the solder layer and the sensitive parameters of the external port under different load conditions. According to the characteristics of port parameters, a data processing method called multiple weight function (WF) network (MWFN) is developed, and the parameter monitoring platform is built. Finally, an IGBT health assessment method based on MWFN is formed. The main advantage of this method is that the best WF is introduced into the neural network to solve the time-consuming problem of updating the high-dimensional weight matrix. In the case study, the active power cycling test was carried out. We obtained the solder layer delamination images by using the 3-D tomography system and the corresponding port parameters by monitoring platform. From the perspective of evaluation results, the proposed method not only performs as well as other mainstream data-driven methods in terms of evaluation accuracy but also has significant advantages in terms of running time.

Under the action of a complex and harsh working environment, the damage of the IGBT power module’s packaging interconnection structure is the primary failure mode. The crack propagation and the bonding interface and the bond point shedding in the bonding wires will seriously affect the device’s electrical interconnection function and heat dissipation ability, resulting in its performance degradation and failure. In this work, the formulation and application of a multiscale approach combined with a cohesive zone model (CZM) were proposed to investigate IGBT bonding wires’ crack propagation. Firstly, the cohesive force model’s principle considering fatigue damage accumulation is analyzed, and the degradation multiscale simulation method of the critical structure of the power module is studied. Secondly, further research on IGBT bonding wires’ degradation behavior is carried out based on the macro and micro scales. The IGBT power module key package structure’s defect evolution model is established to analyze the damage evolution process of the critical package structure. Finally, the accuracy of the model is verified by the experiment analysis. Such a multiscale, mechanism-based cohesive zone model offers a promising approach for modeling and understanding the rate-dependent fracture of IGBT bonding wire crack evolution.

Purpose: The purpose of this paper is to present a failure analysis of the solder layer in a Darlington power transistor in a TO-3 package. Design/methodology/approach: A failed Darlington power transistor in a TO-3 package was examined by different kinds of failure analysis techniques. At first, internal gas analysis was conducted to measure the atmosphere. Then, scanning acoustic microscopy (SAM) was performed to check the quality of the solder layers in the failed device, and the failure location was determined in the solder layer between chip and substrate. Next, the failed device was decapped to observe the defects. After removing the chip from the substrate, energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were applied and the main elemental composition of the solder layer was identified. Findings: Internal gas analysis indicated that the moisture and oxygen contents exceeded the allowed maximum value. Large areas of voids were found in the solder layer by SAM. The main elemental compositions of the solder layer were identified by scanning electron microscopy and EDS. Furthermore, the valences of the chemical components in the solder layer were identified by XPS. Except for the few simple substances of the initial solder material, the chemical formulae of oxidation products in the solder layer were deduced. In addition, the root causes are also discussed. Originality/value: This paper focuses on the solder layer failure of a power transistor. Factors such as the presence of oxygen, voids and other factors, which can cause transistor damage, were comprehensively analyzed. The analysis process is worth learning from and the results can be used to improve the reliability of power devices in this kind of package.

This study proposes an advanced space radiation shielding design method that integrates multi-objective optimization with reliability evaluation to mitigate the impact of harsh space radiation environments on electronic systems. A genetic algorithm is employed to optimize multi-layer shielding configurations with respect to radiation dose reduction, mass efficiency, and structural thickness. To ensure practical applicability, a reliability evaluation framework incorporating uncertainty factors is developed, where shielding designs are considered acceptable when the risk confidence level (CL) remains below 5%. A case study simulating long-duration deep space missions demonstrates that the optimized five-layer shielding configuration reduces the radiation-induced failure rate by approximately 57%, enhancing the long-term reliability of core electronic components to 0.94 over a five-year mission. These findings validate the effectiveness of the proposed approach in supporting the development of reliable, lightweight radiation shielding for future space missions.