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.

Endothermic and exothermic chemically reacting plumes

2008 ◽  
Vol 612 ◽  
pp. 291-310 ◽  
Author(s):  
DEVIN T. CONROY ◽  
STEFAN G. LLEWELLYN SMITH
Keyword(s):  
Reaction Rate ◽  
Exothermic Reaction ◽  
Entrainment Rate ◽  
Heat Of Reaction ◽  
Exothermic Reactions ◽  
Plume Dynamics ◽  
Turbulent Plume ◽  
Chemically Reacting ◽  
Rise Height ◽  
Maximum Rise

We develop a model for a turbulent plume in an unbounded ambient that takes into account a general exothermic or endothermic chemical reaction. These reactions can have an important effect on the plume dynamics since the entrainment rate, which scales with the vertical velocity, will be a function of the heat release or absorption. Specifically, we examine a second-order non-reversible reaction, where one species is present in the plume from a pure source and the other is in the environment. For uniform ambient density and species fields the reaction has an important effect on the deviation from pure plume behaviour as defined by the source parameter Γ. In the case of an exothermic reaction the density difference between the plume and the reference density increases and the plume is ‘lazy’, whereas for an endothermic reaction this difference decreases and the plume is more jet-like. Furthermore, for chemical and density-stratified environments, the reaction will have an important effect on the buoyancy flux because the entrainment rate will not necessarily decrease with distance from the source, as in traditional models. As a result, the maximum rise height of the plume for exothermic reactions may actually decrease with reaction rate if this occurs in a region of high ambient density. In addition, we investigate non-Boussinesq effects, which are important when the heat of reaction is large enough.

Temperature profiles in endothermic and exothermic reactions and the interpretation of experimental rate data

1970 ◽  
Vol 320 (1540) ◽  
pp. 71-100 ◽  
Keyword(s):  
Steady State ◽  
Correction Factor ◽  
Exothermic Reaction ◽  
Kinetic Studies ◽  
Activation Energies ◽  
Uniform Temperature ◽  
Exothermic Reactions ◽  
Arrhenius Function ◽  
Point To Point ◽  
Reacting Systems

Any endothermic or exothermic reaction is accompanied by self-cooling or self-heating. In reacting systems in which heat transfer is controlled by conduction, non-uniform temperature-position profiles are established. Examples of this situation are the exothermic decomposition of gaseous diethyl peroxide and the endothermic decomposition of nitrosyl chloride at low pressures (when convection is unimportant). In kinetic studies, allowance must be made for the non-uniform temperature to derive accurate isothermal velocity constants and Arrhenius parameters. In the present paper, the necessary corrections have been derived for a reactant in the steady state whose reaction rate varies exponentially with temperature and in which the temperature excess varies from point to point, being zero at the boundary (Frank-Kamenetskii’s conditions). The geometries considered are the slab, cylinder and sphere. The temperature gradient at the surface in the steady state ( Г ) occupies a key position, and this is exploited to find the correction factor required to convert 'observed’ rate constants to isothermal conditions, and thence to correct ‘observed’ activation energies and pre-exponential factors. The correction factor is found to be simply related to Frank- Kamenetskii’s δ (a dimensionless measure of heat-release rate). A similar analysis is given for systems hotter or cooler than their surroundings but uniform in temperature—such as well stirred fluid systems or small solid crystals (Semenov’s conditions). In these circumstances, systems of arbitrary geometry may be studied, and no approximation need be made to the Arrhenius function. For either type of boundary condition, uncorrected activation energies are overestimates in exothermic reactions and underestimates in endothermic reactions. Explicit relations are derived for making corrections. Boundary conditions intermediate between the two extremes investigated can also be treated though the resulting expressions are more cumbersome. In an appendix, an alternative ‘experimental’ approach is made to the elimination of errors from measured reaction velocities. This approach identifies the measured velocities with a temperature intermediate between those at centre and surface. The optimum choice, which weights the central and surface temperatures in the ratios 2:1 (slab), 1:1 (cylinder) and 2:3 (sphere), gives exactly correct results for the cylinder and acceptable precision for the slab and sphere even to within 5 K of the explosion limit. Other correction methods are also discussed.

Heat Conduction With Local Heat Sources

2018 ◽  
pp. 289-312
Author(s):  
Yaman Yener ◽  
Sadık Kakaç
Keyword(s):  
Heat Conduction ◽  
Local Heat ◽  
Heat Sources

A Tenfold Reduction in Interface Thermal Resistance for Heat Sink Mounting

2004 ◽  
Vol 1 (3) ◽  
pp. 187-193 ◽  
Author(s):  
D. Van Heerden ◽  
T.R. Rude ◽  
J. Newson ◽  
J. He ◽  
E. Besnoin ◽  
...  
Keyword(s):  
Heat Sink ◽  
Thermal Exposure ◽  
Local Heat ◽  
Heat Sinks ◽  
Thermal Interface ◽  
Exothermic Reactions ◽  
Interface Thermal Resistance ◽  
Order Of Magnitude ◽  
Hot Filament ◽  
Joining Process

Reactive NanoTechnologies (RNT) has developed a new platform joining technology that can form a metallic bond between a chip package and a heat sink and thereby offer a thermal interface resistance that is up to ten times lower than current thermal interface materials (TIM). The joining process is based on the use of reactive multilayer foils as local heat sources. The foils are a new class of nano-engineered materials, in which self-propagating exothermic reactions can be initiated at room temperature with a hot filament or laser. By inserting a multilayer foil between two solder layers and a chip package and heat sink, energy generated by a chemical reaction in the foil heats the solder to melting and consequently bonds the components. The joining process can be completed in air, argon or vacuum in approximately one second. The resulting metallic joints exhibit thermal resistances up to an order of magnitude lower, than current commercial TIMs. We also demonstrate, using numerical modeling, that the thermal exposure of microelectronic packages during joining is very limited. Finally we show numerically that reactive joining can be used to solder Si dies directly to heat sinks without thermally damaging the chip.

NanoBond® Assembly – A Rapid, Room Temperature Soldering Process

2011 ◽  
Vol 2011 (1) ◽  
pp. 000521-000526
Author(s):  
Jacques Matteau
Keyword(s):  
Room Temperature ◽  
New Technology ◽  
Local Heat ◽  
Temperature Sensitive ◽  
Ignition Process ◽  
Light Emitting ◽  
Exothermic Reactions ◽  
Soldering Process ◽  
Order Of Magnitude ◽  
Reactive Foils

Indium Corporation of America has commercialized a new technology that will revolutionize how manufacturers join components using solder materials. (See Figure 1) The joining process is based on the use of reactive multilayer foils as local heat sources. The foils are a new class of nano-engineered materials, in which self-propagating exothermic reactions can be ignited at room temperature through an ignition process. By inserting a multilayer foil between two solder layers and two components, heat generated by the reaction in the foil melts the solder and consequently bonds are completed at room temperature in air, argon or vacuum in approximately one second. The resulting metallic joints exhibit thermal conductivities two orders of magnitude higher, and thermal resistivity’s an order of magnitude lower, than current commercial TIMs. The use of reactive foils as a local heat source eliminates the need for torches, furnaces, or lasers, speeds the soldering processes, and dramatically reduces the total heat that is needed. Thus, temperature-sensitive or small components can be joined without thermal damage or excessive heating. In addition, mismatches in thermal contraction on cooling can be avoided because components see very small increases in temperature. This is particularly beneficial for joining metals to ceramics. The fabrication and characterization of the reactive foils is described, and the value proposition for NanoBonding is presented. This presentation also shows the applicability of this platform technology to many areas of packaging including Thermal Interface Materials, microelectronics, optoelectronics, and Light Emitting Diodes (LEDs)

Identification of the constants of heat transfer in arbitrary thermal modes using local heat sources

1993 ◽  
Vol 65 (6) ◽  
pp. 1173-1181
Author(s):  
A. S. Golosov ◽  
V. I. Zhuk ◽  
A. A. Lopashev ◽  
D. N. Chubarov
Keyword(s):  
Heat Transfer ◽  
Local Heat ◽  
Heat Sources

Numerical modeling of precessing vortex core in the presence of local heat sources

2013 ◽  
Vol 39 (4) ◽  
pp. 333-336 ◽  
Author(s):  
I. P. Zavershinskii ◽  
E. Ya. Kogan ◽  
V. G. Makaryan ◽  
N. E. Molevich ◽  
D. P. Porfir’ev ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Vortex Core ◽  
Local Heat ◽  
Heat Sources ◽  
Precessing Vortex Core
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