Electric current-induced abnormal Cu/γ-InSn4 interfacial reactions

2006 ◽  
Vol 21 (12) ◽  
pp. 3065-3071 ◽  
Author(s):  
Sinn-wen Chen ◽  
Shih-kang Lin
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Electric Current ◽  
Reaction Path ◽  
Interfacial Reactions ◽  
Melting Points ◽  
Transport Enhancement ◽  
Current Stressing ◽  
Phase Layers ◽  
Electromigration Effect

The electromigration effect upon the γ-InSn4/Cu interfacial reactions have been studied by examining the γ-InSn4/Cu/γ-InSn4 couples annealed at 160 °C with and without current stressing. Scallop-type η-Cu6(Sn,In)5 phase layers are formed in the couples without current stressing and at the γ-InSn4/Cu interface where electrons are flowing from the γ-InSn4 to the Cu. The reaction path is Cu/η-Cu6(Sn,In)5/γ-InSn4. However, very large η-Cu6(Sn,In)5 compounds are found at the Cu/γ-InSn4 interface where electrons are from Cu to the γ-InSn4. Although the melting points of both γ-InSn4 and Cu are higher than 160 °C, the liquid phase is formed at 160 °C in the electrified couple at the downstream γ-InSn4 phase near the Cu/γ-InSn4 interface. The reaction path is Cu/η-Cu6(Sn,In)5/liquid/γ-InSn4. The liquid phase propagates along the grain boundaries of the γ-InSn4 matrix. The very large η-Cu6(Sn,In)5 compounds are the coupling results of the liquid phase penetration and the Cu transport enhancement due to electromigration.

Effects of electromigration on interfacial reactions in cast Sn/Cu joints

2007 ◽  
Vol 22 (3) ◽  
pp. 695-702 ◽  
Author(s):  
Sinn-Wen Chen ◽  
Chao-Hong Wang
Keyword(s):  
Sample Preparation ◽  
Grain Boundaries ◽  
Electric Current ◽  
Interfacial Reactions ◽  
Casting Method ◽  
Sandwich Type

The Sn/Cu/Sn/Cu/Sn sandwich-type couples prepared by the casting method are used for examining the effects of electromigration on Sn/Cu interfacial reactions. The samples are reacted at 170 and 180 °C for 24–240 h by passing an electric current with a density of 5000 A/cm2. At the interfaces where electrons flow from the Sn side to the Cu side, uniform layers of Cu6Sn5 and Cu3Sn are formed. The results are similar to those without passage of an electric current. The relatively thicker Cu6Sn5 layer is attributed to the extra Cu source from the dissolved Cu during the sample preparation. At the interfaces where electrons flow from the Cu side to the Sn side, large and nonplanar Cu6Sn5 phase regions are formed. Formation of large Cu6Sn5 regions is the result of electromigration-enhanced Cu diffusion through the grain boundaries and surfaces.

Effects of temperature on interfacial reactions in γ–InSn4/Ni couples

2006 ◽  
Vol 21 (5) ◽  
pp. 1161-1166 ◽  
Author(s):  
Sinn-wen Chen ◽  
Shih-kang Lin
Keyword(s):  
Liquid Phase ◽  
Reaction Layer ◽  
Reaction Path ◽  
Interfacial Reactions ◽  
Phase Layer ◽  
Homogeneous Phase ◽  
Nickel Substrates ◽  
Solid Phases ◽  
Effects Of Temperature

Interfacial reactions in γ–InSn4(Sn–20 at.% In)/Ni couples at 130, 140, 150, and 160 °C were investigated. Ni3Sn4phase with significant indium solubility was formed in the couple reacted at 130 and 140 °C, and the reaction path was γ–InSn4/Ni3Sn4/Ni. For the couples reacted at 150 and 160 °C, even though both γ–InSn4and Ni were solid phases, the liquid phase was formed in the couples. A distinguished feature was the nickel substrates becoming nonplanar with spikes at various locations and the Ni3Sn4phase layer on top of the nickel spikes. Except at regions near the nickel spikes, the reaction layer consisted of precipitates and was not a homogeneous phase. The reaction path is γ–InSn4/Ni3Sn4/Ni at the location with Ni3Sn4phase growing on Ni. However, if the Ni3Sn4phase does not nucleate, the liquid phase forms at the interface with accumulation of indium atoms, and the reaction path is γ–InSn4/ liquid/liquid + Ni3Sn4/Ni.

Interfacial reactions in the Sn–20 at.% In/Cu and Sn–20 at.% In/Ni couples at 160 °C

2006 ◽  
Vol 21 (7) ◽  
pp. 1712-1717 ◽  
Author(s):  
Shih-kang Lin ◽  
Sinn-wen Chen
Keyword(s):  
Melting Point ◽  
Liquid Phase ◽  
Reaction Rate ◽  
Reaction Path ◽  
Interfacial Reactions ◽  
Phase Layer ◽  
Electronic Products ◽  
Ni Substrate ◽  
Consumption Rates ◽  
Peculiar Phenomenon

Sn–In alloys are promising low-melting-point Pb-free solders. Cu and Ni are common substrates in the electronic products. This study examines the interfacial reactions in the Sn–20 at.% In(γ–InSn4)/Cu and Sn–20 at.% In/Ni couples at 160 °C. Only the η–Cu6Sn5 phase layer is formed in the Sn–20 at.% In/Cu couple, and the layer grows thicker with longer reaction time. The reaction path is γ–InSn4/η–Cu6Sn5/Cu. A peculiar phenomenon with the bulging of the couple near the Ni substrate is found in the Sn–20 at.% In/Ni couple. A liquid phase is formed by interfacial reaction in the solid/solid Sn–20 at.% In/Ni couple at 160 °C, and the reaction path is γ–InSn4/liquid/δ–Ni3Sn4 + liquid/(δ–Ni3Sn4)/Ni. Usually Ni has a slower reaction rate with solders; however, the consumption rates of Ni substrate are much higher than those of Cu substrate in this study when they are in contact with the Sn–20 at.% In alloy at 160 °C due to the formation of the liquid phase in the Sn–20 at.% In/Ni couple.

Elucidation of block boundaries as the dissolution channels in hydrated cement

1978 ◽  
Vol 36 (1) ◽  
pp. 484-485
Author(s):  
N.V. Belov ◽  
U.I. Papiashwili ◽  
B.E. Yudovich
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Benzoyl Peroxide ◽  
Phase Contrast ◽  
Active Role ◽  
Point Of View ◽  
Hardened Cement ◽  
Hydrated Cement ◽  
Hardened Cement Paste

It has been almost universally adopted that dissolution of solids proceeds with development of uniform, continuous frontiers of reaction.However this point of view is doubtful / 1 /. E.g. we have proved the active role of the block (grain) boundaries in the main phases of cement, these boundaries being the areas of hydrate phases' nucleation / 2 /. It has brought to the supposition that the dissolution frontier of cement particles in water is discrete. It seems also probable that the dissolution proceeds through the channels, which serve both for the liquid phase movement and for the drainage of the incongruant solution products. These channels can be appeared along the block boundaries.In order to demonsrate it, we have offered the method of phase-contrast impregnation of the hardened cement paste with the solution of methyl metacrylahe and benzoyl peroxide. The viscosity of this solution is equal to that of water.

Role of the solid/liquid interface faceting in rapid penetration of a liquid phase along grain boundaries

2001 ◽  
Vol 49 (7) ◽  
pp. 1123-1128 ◽  
Author(s):  
D. Chatain ◽  
E. Rabkin ◽  
J. Derenne ◽  
J. Bernardini
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Liquid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid

scholarly journals Bringing naturally-occurring saturated fatty acids into biomedical research

2021 ◽  
Author(s):  
Ke Xue ◽  
Shuyi Lv ◽  
Chunlei Zhu
Keyword(s):  
Fatty Acids ◽  
Liquid Phase ◽  
Biomedical Research ◽  
Low Cost ◽  
Saturated Fatty Acids ◽  
Heat Of Fusion ◽  
Melting Points ◽  
Naturally Occurring ◽  
Large Heat ◽  
Solid Liquid

Naturally-occurring saturated fatty acids (NSFAs) have emerged as a class of promising biomaterials due to their low cost, chemical stability, well-defined melting points, large heat of fusion, reversible solid-liquid phase...

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