Modeling and characterizing the propagation velocity of exothermic reactions in multilayer foils

1997 ◽  
Vol 82 (3) ◽  
pp. 1178-1188 ◽  
Author(s):  
A. B. Mann ◽  
A. J. Gavens ◽  
M. E. Reiss ◽  
D. Van Heerden ◽  
G. Bao ◽  
...  
Keyword(s):  
Propagation Velocity ◽  
Exothermic Reactions ◽  
Multilayer Foils

Exothermic reactions in cold-rolled Ni/Al reactive multilayer foils

2008 ◽  
Vol 23 (2) ◽  
pp. 367-375 ◽  
Author(s):  
X. Qiu ◽  
J. Graeter ◽  
L. Kecskes ◽  
J. Wang
Keyword(s):  
Phase Evolution ◽  
Reaction Process ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Exothermic Reactions ◽  
X Ray ◽  
Multilayer Foils ◽  
Cold Rolled ◽  
Two Peaks ◽  
Evolution Sequence

Exothermic reactions in cold-rolled Ni/Al reactive multilayer foils were investigated in this study. A two-stage reaction process was observed in the self-propagating reactions in the cold-rolled foils that were ignited by a point-source flame. Foils taken out of the flame after completing the first stage of the reaction process were compared to those allowed to complete both stages. Differences in the phase-evolution sequence from the two types of foils were studied by differential scanning calorimetry (DSC), using slow and controlled heating of the samples. Several exothermic peaks could be identified from the DSC thermograms for both types of foils. Using the DSC, both the as-cold-rolled and partially reacted foils were heated to each peak temperature to identify the reaction product associated with each peak. X-ray diffraction and scanning electron microscopy analyses showed that the first two peaks corresponded to the formation of Al3Ni, while the third peak corresponded to the formation of AlNi.

Reactive Multilayer Foils for Silicon Wafer Bonding

2006 ◽  
Vol 968 ◽  
Author(s):  
Xiaotun Qiu ◽  
Jiaping Wang
Keyword(s):  
Wafer Bonding ◽  
Heat Exposure ◽  
Exothermic Reaction ◽  
Local Heat ◽  
Heat Of Reaction ◽  
Heat Sources ◽  
Exothermic Reactions ◽  
Multilayer Foils ◽  
Leakage Test ◽  
Localized Heating

ABSTRACTIn this study silicon wafers were bonded using Al/Ni reactive multilayer foils as local heat sources for melting solder layers. Exothermic reactions in Al/Ni reactive multilayer foils were investigated by XRD and DSC. XRD measurements showed that dominant product after exothermic reaction was ordered B2 AlNi compound. The heat of reaction was calculated to be -57.9 KJ/mol by DSC. With Al/Ni reactive multilayer foil, localized heating can be achieved during bonding process. Both experimental measurements and numerical simulation showed that the heat exposure to the wafers was highly limited and localized. Moreover, leakage test showed that this bonding approach possessed a good hermeticity.

Modeling Self-Propagating Exothermic Reactions in Multilayer Systems

1997 ◽  
Vol 481 ◽  
Author(s):  
S. Jayaraman ◽  
A. B. Mann ◽  
O. M. Knio ◽  
D. Van Heerden ◽  
G. Bao ◽  
...  
Keyword(s):  
Critical Thickness ◽  
Temperature Profiles ◽  
Bilayer Thickness ◽  
Free Standing ◽  
Multilayer Systems ◽  
Exothermic Reactions ◽  
Multilayer Foils ◽  
Reaction Characteristics ◽  
Reactive Foils ◽  
Experimental Values

ABSTRACTSelf-propagating reactions in free-standing multilayer foils provide a unique opportunity to study very rapid, diffusion-based transformations in non-equilibrium material systems. To fully understand the coupling between mass and thermal diffusion controlling these reactions and to optimize the commercial use of reactive foils, we have undertaken analytical and numerical modeling. Our analytical model predicts an increase in the reaction velocities with decreasing bilayer thickness down to a critical bilayer thickness and a reversal in this trend below the critical thickness. Predicting reaction characteristics such as the flame thermal width, the reaction zone width and the effect of variations in material properties with temperature has proven analytically intractable. To overcome these limitations, we have also used numerical methods to determine the composition and temperature profiles ahead of the reaction front for different multilayer periods and premixing. The results are compared with experimental values where possible.

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