Three-dimensional (3D) interconnection technology based on glass through vias (TGVs) has been used to integrate passive devices, and optoelectronic devices due to its superior electrical qualities, outstanding mechanical stability, and lower cost. Nevertheless, the performance and reliability of the device will be impacted by the thermal stress brought on by the mismatch of the coefficient of thermal expansion among multi-material structures and the complicated structure of TGV. This paper focuses on thermal stress evolution in different geometric and material parameters and the development of a controlled method for filling polymers in TGV interconnected structures. In addition, a numerical study based on the finite element (FE) model has been conducted to analyze the stress distribution of the different thicknesses of TGV-Cu. Additionally, a TGV interconnected structure model with a polymer buffer layer is given to solve the crack problem appearing at the edge of RDL. Meanwhile, after practical verification, in comparison to the experimental results, the FE model was shown to be highly effective and accurate for predicting the evolution of stress, and several recommendations were made to alleviate stress-related reliability concerns. An improved manufacturing process flow for the TGV interconnected structure was proposed and verified as feasible to address the RDL crack issue based on the aforementioned research. It provides helpful information for the creation of highly reliable TGV connection structures.

As traditional lead-based solders are banned and replaced by lead-free solders, the drop impact reliability is becoming increasingly crucial because there is little understanding of mechanical behaviors of these lead-free solders at high strain rates. In this paper, mechanical properties of one lead-based solder, Sn37Pb, and two lead-free solders, Sn3.5Ag and Sn3.0Ag0.5Cu, were investigated at strain rates that ranged from $600s−1$ to $2200s−1$ by the split Hopkinson pressure and tensile bar technique. At high strain rates, tensile strengths of lead-free solders are about 1.5 times greater than that of the Sn37Pb solder, and also their ductility are significantly greater than that of the Sn37Pb. Based on the experimental data, strain rate dependent Johnson–Cook models for the three solders were derived and employed to predict behaviors of solder joints in a board level electronic package subjected to standard drop impact load. Results indicate that for the drop impact analysis of lead-free solder joints, the strain rate effect must be considered and rate-dependent material models of lead-free solders are indispensable.

The study presented in this paper contributes to quantification of the correlations between resistance degradation and Al metallization layer reconstruction observed in high-power insulated gate bipolar transistor (IGBT) modules during power cycling. The microstructure evolution that occurs in the Al metallization layer during power cycling was investigated via electron and ion microscopy, and the surface roughness was measured and used to characterize the Al metallization degradation. An electrical four-point probe method was used to examine the change in the electrical parameter (resistance) of the Al metallization layer in the IGBT modules. The effect of Al metallization layer reconstruction on its electrical performance was investigated by experimental observation and finite element analysis (FEA). The results show that both the Al metallization layer surface morphology and cracks propagating across the Al metallization layer thickness significantly affect the metallization resistance. In the initial and mid-point stages of power cycling, the increase in the Al metallization layer resistance is consistent with the surface roughness evolution. Near the ultimate lifetime of the IGBT module, the change in the resistance strongly depends on the crack density.

Non-small cell lung cancer (NSCLC) remains the most frequently diagnosed lung cancer and the leading cause of cancer-related mortality worldwide. PD-1/PD-L1 axis inhibitors have changed the treatment paradigm for various cancer types, including NSCLC. However, success of these inhibitors in lung cancer clinic is severely limited by their inability to inhibit the PD-1/PD-L1 signaling axis due to heavy glycosylation and heterogeneity expression of PD-L1 in NSCLC tumor tissue. Taking advantage of the facts that tumor cell derived nanovesicles could efficiently accumulate in the homotypic tumor sites due to their innate targeting abilities and that specific and high affinity existed between PD-1 and PD-L1, we developed NSCLC targeting biomimetic nanovesicles (NV) cargos from genetically engineered NSCLC cell lines that overexpressed PD-1 (P-NV). We showed that P-NVs efficiently bound NSCLC cells in vitro and targeted tumor nodules in vivo. We further loaded P-NVs with 2-deoxy-D-glucose (2-DG) and doxorubicin (DOX), and found that these drugs co-loaded P-NVs efficiently shrank lung cancers in mouse models for both allograft and autochthonous tumor. Mechanistically, drug-loaded P-NVs efficiently caused cytotoxicity to tumor cells and simultaneously activated anti-tumor immunity function of tumor-infiltrating T cells. Our data therefore strongly argue that 2-DG and DOX co-loaded, PD-1-displaying nanovesicles is a highly promising therapy for treatment of NSCLC in clinic. STATEMENT OF SIGNIFICANCE: Lung cancer cells overexpressing PD-1 are developed for preparing nanoparticles (P-NV). PD-1s displayed on NVs enhance their homologous targeting abilities to tumor cells expressing PD-L1s. Chemotherapeutics such as DOX and 2-DG, are packaged in such nanovesicles (PDG-NV). These nanovesicles efficiently delivered chemotherapeutics to tumor nodules specifically. The synergy between DOX and 2-DG is observed in inhibiting lung cancer cells in vitro and in vivo. Importantly, 2-DG causes deglycosylation and downregulation of PD-L1 on tumor cells while PD-1 displayed on nanovesicles' membrane blocks PD-L1 on tumor cells. 2-DG loaded nanoparticles thus activate anti-tumor activities of T cells in the tumor microenvironment. Our work thus highlights the promising antitumor activity of PDG-NVs, which warrants further clinical evaluation.

Six-side molded wafer-level chip scale package (mWLCSP) is a novel and attractive packaging method for smart phone applications due to its lower cost, better electrical performance and higher long-term reliability. Nevertheless, wafer warpage in different manufacturing processes is a significant issue for six-side mWLCSP. This paper focuses on wafer warpage evolution in different packaging processes and the development of control method for six-side mWLCSP. A quarter wafer-level finite element (FE) model and strip-level FE model were established to simulate the actual packaging processes by element birth and death method and restart technology. Both of the two FE models were proved quite efficient and accurate for warpage prediction compared to the experimental results. The effect of geometric parameters and material parameters on the maximum warpage value were studied based on the two established FE warpage models, and some recommendations were given for warpage optimization. Based on the above studies, an improved manufacturing process flow for six-side mWLCSP was presented and proved feasible to control the maximum warpage value under 3 mm. It offers an insight work for the development and warpage control of six-side mWLCSP and other wafer level molded packages.