Damage Mechanism of Cu6Sn5 Intermetallics Due to Cyclic Polymorphic Transitions.

The formation of high-melting-point Cu6Sn5 interconnections is crucial to overcome the collapse of Sn-based micro-bumps and to produce reliable intermetallic interconnections in three-dimensional (3D) packages. However, because of multiple reflows in 3D package manufacturing, Cu6Sn5 interconnections will experience cyclic polymorphic transitions in the solid state. The repeated and abrupt changes in the Cu6Sn5 lattice due to the cyclic polymorphic transitions can cause extreme strain oscillations, producing damage at the surface and in the interior of the Cu6Sn5 matrix. Moreover, because of the polymorphic transition-induced grain splitting and superstructure phase formation, the reliability of Cu6Sn5 interconnections will thus face great challenges in 3D packages. In addition, the Cu6Sn5 polymorphic transition is structure-dependent, and the η ’↔ η polymorphic transition will occur at the surface while the η ’↔ ηs ↔ η polymorphic transition will occur in the deep matrix. This study can provide in-depth understanding of the structural evolution and damage mechanism of Cu6Sn5 interconnections in real 3D package manufacturing

Damage Mechanism of Cu<sub>6</sub>Sn<sub>5</sub> Intermetallics Due to Cyclic Polymorphic Transitions

The formation of high-melting-point Cu6Sn5 interconnections is crucial to overcome the collapse of Sn-based micro-bumps and produce reliable intermetallic interconnections in three-dimensional (3D) package. However, because of the multiple reflows in 3D package manufacturing, Cu6Sn5 interconnections will experience the cyclic polymorphic transitions in the solid state. The repeated and abrupt change in the Cu6Sn5 lattice due to the cyclic polymorphic transitions can cause extreme strain oscillations, producing damages at the surface and in the interior of the Cu6Sn5 matrix. Moreover, because of the polymorphic-transition-induced grain splitting and superstructure phase formation, the reliability of Cu6Sn5 interconnections will thus face great challenges in 3D package. In addition, the Cu6Sn5 polymorphic transition is structure-dependent, and the &amp;eta;&amp;prime;&amp;harr;&amp;eta; polymorphic transition will occur at the surface while the &amp;eta;&amp;prime;&amp;harr;&amp;eta;s&amp;harr;&amp;eta; polymorphic transition will occur in the deep matrix. Our results can provide in-depth understandings of structural evolution and damage mechanism of Cu6Sn5 interconnections in real 3D package manufacturing.</jats:p

Damage Mechanism of Cu6Sn5 Intermetallics Due to Cyclic Polymorphic Transitions

The formation of high-melting-point Cu6Sn5 interconnections is crucial to overcome the collapse of Sn-based micro-bumps and to produce reliable intermetallic interconnections in three-dimensional (3D) packages. However, because of multiple reflows in 3D package manufacturing, Cu6Sn5 interconnections will experience cyclic polymorphic transitions in the solid state. The repeated and abrupt changes in the Cu6Sn5 lattice due to the cyclic polymorphic transitions can cause extreme strain oscillations, producing damage at the surface and in the interior of the Cu6Sn5 matrix. Moreover, because of the polymorphic transition-induced grain splitting and superstructure phase formation, the reliability of Cu6Sn5 interconnections will thus face great challenges in 3D packages. In addition, the Cu6Sn5 polymorphic transition is structure-dependent, and the η′↔η polymorphic transition will occur at the surface while the η′↔ηs↔η polymorphic transition will occur in the deep matrix. This study can provide in-depth understanding of the structural evolution and damage mechanism of Cu6Sn5 interconnections in real 3D package manufacturing.</jats:p

Transcriptome Analysis of the Chicken Follicular Theca Cells with miR-135a-5p Suppressed

As a class of transcription regulators, numerous miRNAs have been verified to participate in regulating ovary follicular development in chickens (Gallus gallus). Previously we showed that gga-miR-135a-5p has significant differential expression between high and low-yield chicken ovaries, and the abundance of gga-miR-135a-5p is significantly higher in follicular theca cells than in granulosa cells. However, the exact role of gga-miR-135a-5p in chicken follicular theca cells is unclear. In this study, primary chicken follicular theca cells were isolated and then transfected with gga-miR-135a-5p inhibitor. Transcriptome sequencing was performed in chicken follicular theca cells with or without transfection. Differentially expressed genes (DEGs) were analyzed using bioinformatics. A dual-luciferase reporter assay was used to verify the target relationship between gga-miR-135a-5p and predicted targets within the DEGs. Compared with the normal chicken follicle theca cells, 953 up-regulated and 1060 down-regulated genes were detected in cells with gga-miR-135a-5p inhibited. The up-regulated genes were significantly enriched in Gene Ontology terms and pathways involved in cell proliferation and differentiation. In chicken follicular theca cells, Krüppel-like factor 4 (KLF4), ATPase phospholipid transporting 8A1 (ATP8A1), and Complexin-1 (CPLX1) were significantly up-regulated when the expression of gga-miR-135a-5p was inhibited. In addition, KLF4, ATP8A1, and CPLX1 confirmed as targets of gga-miR-135a-5p by using a dual-luciferase assay in vitro. The results suggest that gga-mir-135a-5p may involve in proliferation and differentiation in chicken ovarian follicular theca cells by targeting KLF4, ATP8A1, and CPLX1

Transcriptome Analysis of the Chicken Follicular Theca Cells with miR-135a-5p Suppressed

Abstract As a class of transcription regulators, numerous miRNAs have been verified to participate in regulating ovary follicular development in chickens (Gallus gallus). Previously we showed that gga-miR-135a-5p has significant differential expression between high and low-yield chicken ovaries, and the abundance of gga-miR-135a-5p is significantly higher in follicular theca cells than in granulosa cells. However, the exact role of gga-miR-135a-5p in chicken follicular theca cells is unclear. In this study, primary chicken follicular theca cells were isolated and then transfected with gga-miR-135a-5p inhibitor. Transcriptome sequencing was performed in chicken follicular theca cells with or without transfection. Differentially expressed genes (DEGs) were analyzed using bioinformatics. A dual-luciferase reporter assay was used to verify the target relationship between gga-miR-135a-5p and predicted targets within the DEGs. Compared with the normal chicken follicle theca cells, 953 up-regulated and 1060 down-regulated genes were detected in cells with gga-miR-135a-5p inhibited. The up-regulated genes were significantly enriched in Gene Ontology terms and pathways involved in cell proliferation and differentiation. In chicken follicular theca cells, Krüppel-like factor 4 (KLF4), ATPase phospholipid transporting 8A1 (ATP8A1), and Complexin-1 (CPLX1) were significantly up-regulated when the expression of gga-miR-135a-5p was inhibited. In addition, KLF4, ATP8A1, and CPLX1 confirmed as targets of gga-miR-135a-5p by using a dual-luciferase assay in vitro. The results suggest that gga-mir-135a-5p may involve in proliferation and differentiation in chicken ovarian follicular theca cells by targeting KLF4, ATP8A1, and CPLX1.</jats:p