Corrosion Mechanism of Foamed Slag on the Lightweight Corundum-Spinel Castable

Abstract Cu needs a higher level of ultrasound combined with bonding force to be bonded to the Al pad properly, not just because Cu is harder than Au, but it is also harder to initiate intermetallic compounds (IMC) formation during bonding. This increases the chances of damaging the metal/low k stack under the bondpad. This paper presents a fundamental study of IMC as well as one example of a failure mode of Cu/Al bonded devices, all based on detailed analysis using scanning electron microscopy, scanning transmission electron microscopy, energy dispersive spectrometers, and transmission electron microscopy. It presents a case study showing a corrosion mechanism of Cu/Al ballbond after 168hr UHAST stress. It is observed that all Cu9Al4 was consumed, while very little copper aluminide remained after 168 hours of UHAST stressing.

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Unique Autoclave Stress Induced Failure Mechanism

ISTFA 2005: Conference Proceedings from the 31st International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2005p0427 ◽

2005 ◽

Author(s):

John Butchko ◽

Bruce T. Gillette

Keyword(s):

Corrosion Rate ◽

Grain Boundary ◽

Failure Analysis ◽

Failure Mechanism ◽

Metal Corrosion ◽

Corrosion Mechanism ◽

Reliability Testing ◽

Process Change ◽

Transistor Reliability ◽

Pass Through

Abstract Autoclave Stress failures were encountered at the 96 hour read during transistor reliability testing. A unique metal corrosion mechanism was found during the failure analysis, which was creating a contamination path to the drain source junction, resulting in high Idss and Igss leakage. The Al(Si) top metal was oxidizing along the grain boundaries at a faster rate than at the surface. There was subsurface blistering of the Al(Si), along with the grain boundary corrosion. This blistering was creating a contamination path from the package to the Si surface. Several variations in the metal stack were evaluated to better understand the cause of the failures and to provide a process solution. The prevention of intergranular metal corrosion and subsurface blistering during autoclave testing required a materials change from Al(Si) to Al(Si)(Cu). This change resulted in a reduced corrosion rate and consequently prevented Si contamination due to blistering. The process change resulted in a successful pass through the autoclave testing.

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Corrosion mechanism of sulfate, chloride, and tetrafluoroborate ions interacted with Ni-19 wt% Cr coating: A combined experimental study and molecular dynamics simulation

Journal of Molecular Liquids ◽

10.1016/j.molliq.2020.114243 ◽

2020 ◽

Vol 319 ◽

pp. 114243 ◽

Cited By ~ 1

Author(s):

Zhina Razaghi ◽

Milad Rezaei

Keyword(s):

Molecular Dynamics ◽

Experimental Study ◽

Molecular Dynamics Simulation ◽

Dynamics Simulation ◽

Corrosion Mechanism ◽

Cr Coating

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New Corrosion Mechanism Observed at Ag/Al Metallization of n-type Bifacial Solar Cells

2020 47th IEEE Photovoltaic Specialists Conference (PVSC) ◽

10.1109/pvsc45281.2020.9300672 ◽

2020 ◽

Author(s):

Taeko Semba

Keyword(s):

Solar Cells ◽

Corrosion Mechanism ◽

Al Metallization

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Corrosion of ternary borosilicate glass in acidic solution studied in operando by fluid-cell Raman spectroscopy

npj Materials Degradation ◽

10.1038/s41529-021-00182-5 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Christoph Lenting ◽

Thorsten Geisler

Keyword(s):

Raman Spectroscopy ◽

Nuclear Waste ◽

Numerical Models ◽

Adsorbed Water ◽

Corrosion Mechanism ◽

Borosilicate Glasses ◽

Long Term Storage ◽

In Operando ◽

High Level ◽

Fluid Cell

AbstractFluid-cell Raman spectroscopy is a space and time-resolving application allowing in operando studies of dynamic processes during solution–solid interactions. A currently heavily debated example is the corrosion mechanism of borosilicate glasses, which are the favoured material for the immobilization of high-level nuclear waste. With an upgraded fluid-cell lid design made entirely from the glass sample itself, we present the polymerization of the surface alteration layer over time in an initially acidic environment, including the differentiation between pore and surface-adsorbed water within it. Our results support an interface-coupled dissolution-precipitation model, which opposes traditional ion-exchange models for the corrosion mechanism. A sound description of the corrosion mechanism is essential for reliable numerical models to predict the corrosion rate of nuclear waste glasses during long-term storage in a geological repository.

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Effect of Oxide Scale Microstructure on Atmospheric Corrosion Behavior of Hot Rolled Steel Strip

Coatings ◽

10.3390/coatings11050517 ◽

2021 ◽

Vol 11 (5) ◽

pp. 517

Author(s):

Bin Sun ◽

Lei Cheng ◽

Chong-Yang Du ◽

Jing-Ke Zhang ◽

Yong-Quan He ◽

...

Keyword(s):

Corrosion Resistance ◽

Oxide Scale ◽

Corrosion Product ◽

Corrosion Behavior ◽

Corrosion Test ◽

Atmospheric Corrosion ◽

Corrosion Mechanism ◽

Type I ◽

Rust Layer ◽

Hot Rolled

The atmospheric corrosion behavior of a hot-rolled strip with four types (I–IV) of oxide scale was investigated using the accelerated wet–dry cycle corrosion test. Corrosion resistance and porosity of oxide scale were studied by potentiometric polarization measurements. Characterization of samples after 80 cycles of the wet–dry corrosion test showed that scale comprised wüstite and magnetite had strongest corrosion resistance. Oxide scale composed of inner magnetite/iron (>70%) and an outer magnetite layer had the weakest corrosion resistance. The corrosion kinetics (weight gain) of each type of oxide scale followed an initial linear and then parabolic (at middle to late corrosion) relationship. This could be predicted by a simple kinetic model which showed good agreement with the experimental results. Analysis of the potentiometric polarization curves, obtained from oxide coated steel electrodes, revealed that the type I oxide scale had the highest porosity, and the corrosion mechanism resulted from the joint effects of electrochemical behavior and the porosity of the oxide scale. In the initial stage of corrosion, the corrosion product nucleated and an outer rust layer formed. As the thickness of outer rust layer increased, the corrosion product developed on the scale defects. An inner rust layer then formed in the localized pits as crack growth of the scale. This attacked the scale and expanded into the substrate during the later stage of corrosion. At this stage, the protective effect of the oxide scale was lost.

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