Surface mount technology (SMT) plays an important role in integrated circuits, but due to thermal stress alternation caused by temperature cycling, it tends to have thermo-mechanical reliability problems. At the same time, considering the environmental and health problems of lead (Pb)-based solders, the electronics industry has turned to lead-free solders, such as ternary alloy Sn-3Ag-0.5Cu (SAC305). As lead-free solders exhibit visco-plastic mechanical properties significantly affected by temperature, their thermo-mechanical reliability has received considerable attention. In this study, the interface delamination of an SMT solder joint using a SAC305 alloy under temperature cycling has been analyzed by the nonlinear finite element method. The results indicate that the highest contact pressure at the four corners of the termination/solder horizontal interface means that delamination is most likely to occur, followed by the y-direction side region of the solder/land interface and the top arc region of the termination/solder vertical interface. It should be noted that in order to keep the shape of the solder joint in the finite element model consistent with the actual situation after the reflow process, a minimum energy-based morphology evolution method has been incorporated into the established finite element model. Eventually, an Improved Efficient Global Optimization (IEGO) method was used to optimize the geometry of the SMT solder joint in order to reduce the contact pressure at critical points and critical regions. The optimization result shows that the contact pressure at the critical points and at the critical regions decreases significantly, which also means that the probability of thermal-induced delamination decreases.

With the development of miniaturization and integration of electronic devices, the conventional manifold microchannels (MMCs) structure has been unable to meet the heat dissipation requirements caused by the rapid growth of internal heat flux. There is an urgent need to design a new heat dissipation structure with higher heat dissipation capacity to ensure the working stability and life of electronic devices. In this paper, we designed a novel manifold dual-microchannel (MDMC) cooling system that embedded the microchannel structure into the manifold microchannel structure. The MDMC not only has good heat dissipation performance that can meet the development needs of electronic equipment to miniaturization and integration, but also has a compact structure that does not increase the overall thickness and volume compared with MMC. The high temperature uniformity and heat transfer performance of MDMC are significantly improved compared to MMC. The T_max is reduced by 13.6% and 17.5% at the heat flux density of 300 W/cm² and 700 W/cm², respectively. In addition, the influence of the inlet−2 velocity and the total microchannels number on the heat transfer performance of the MDMC structure are numerically investigated. The results show that the decrease rate of T_max and ΔT is about 6.69% and 16% with the increase of inlet−2 velocity from 1.2 m/s to 2.4 m/s and microchannels number from 10 to 48, respectively. At the same time, the best temperature uniformity is obtained when the number of microchannels is 16.

There are a large number of interconnections in the microwave module, among which the lead wire interconnection is widely used. Under the environmental load, the solder joint of the lead wire interconnection often appears to have cracks and other defects, which directly affect the return loss and insertion loss when transmitting electrical signals through solder joints, and indirectly affect the performance of the microwave module. For this reason, the segmented modeling method is realized by segmenting the lead wire interconnection structure into two parts in this paper, and the equivalent circuit model of the lead wire interconnection with the cracked solder joint is established using the equivalent circuit method. The correlation mechanism of the shape of the solder joint of the lead wire interconnection is studied, and formulas for predicting electrical performance based on return loss and insertion loss are derived. This paper realizes the prediction of the electrical performance of the lead wire interconnection with the defect, and can provide a reference for engineers and technicians.

With the huge requirement of high frequency, multi-function and high reliability, the quality of microwave circuit interconnection has become an important factor that significantly affects the improvement of microwave electronic system performance. This paper has presented an identification method for flexible conductor wire interconnection (FCWI) electromechanical coupling parameters in microwave circuits with the consideration of their interaction effect. First, a parametric characterization cascade function has been proposed to design the FCWI, and consequently, a three-dimensional electromagnetic structure model of FCWI has been developed and verified. In order to identify the electromechanical coupling parameters of the flexible interconnection considering the interaction effect effectively, this paper has used the range multi-objective function to select the optimal level of the configuration parameter of the flexible interconnection that affects the signal transmission loss. Based on the variance analysis and range analysis of the experimental results, the comprehensive judgment criterion of electromechanical coupling parameters of flexible interconnection can be defined, and therefore, the calculation of electromechanical coupling degree can be derived and the electromechanical coupling property identification of flexible interconnection has been obtained. An example has been used afterwards to verify the accuracy of the proposed method. The method proposed in this paper can be a promising tool for microwave circuit comprehensive design and the optimization of its interconnection, considering both mechanical reliability and electrical performance.

With the demand for more powerful functions and miniaturization of electronic equipment, the requirements for complex interconnection design and manufacturing in electronic packaging are increasing. The pros and cons of interconnection configuration have a serious impact on its electrical performance, and have become a key factor affecting the development of complex interconnection in electronic packaging. In order to better study the influence mechanism of the configuration parameters of lead interconnection, a method for predicting the electrical performance of lead interconnection in electronic packaging based on configuration characteristics is presented. First, the configuration parameters of lead interconnection are extracted, then the parameterized characterization of lead interconnection is carried out. Taking the half-envelope rectangular lead interconnection as an example, the road coupling model of lead interconnection based on range analysis, variance analysis and response surface method is built and experimentally verified. Finally, the influence mechanism of the configuration characteristics of lead interconnect on electrical performance is analyzed. The work carried out provides theoretical guidance for the lead interconnection design and fast prediction of electrical signal transmission performance in electronic packaging.

The through-silicon via (TSV) technology due to its fine feature dimensions and high operating frequency, introduces complexity in performance analysis. Traditional analytical methods can become unrealistic when confronting the multiple considerations of thermo-mechanical and signal transmission characteristics. This paper introduces a collaborative optimization framework incorporating the multi-output multi-fidelity surrogate model (MOMFSM) with a multi-objective optimizer. This framework aims to accelerate TSV structure design accounting for the multiphysics effect with low computational demand and uncompromised accuracy. The MOMFSM improves predictive accuracy by capturing the correlations between various physical outputs of TSV and fuses data of different fidelities, reducing reliance on high-fidelity data. Employing the rapid and precise MOMFSM, thermal stress and S-parameters distributions in TSV were simulated and utilized as analytical functions for design objectives. The multiobjective optimizer conducts an efficient multiphysics collaborative optimization, yielding a set of non-dominated optimization solutions. The technique for order preference by similarity to an ideal solution (TOPSIS) was employed to derive the best compromise solution from these options. The results indicate that the thermal stress in TSV interconnection was reduced from 690.3 MPa to 635.4 MPa, the S ₁₁ at 30 GHz decreased from −26.29 dB to −39.93 dB, and the S ₂₁ at 30GHz increased from −0.646 dB to −0.443dB. Moreover, this study provides valuable insights for the comprehensive enhancement of TSV multi-physics performance and offers robust support for IC interconnection design.