scholarly journals Investigations on the Adhesive Contact Behaviors between a Viscoelastic Stamp and a Transferred Element in Microtransfer Printing

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1201
Author(s):  
Ling Jiang ◽  
Mengjie Wu ◽  
Qiuping Yu ◽  
Yuxia Shan ◽  
Yuyan Zhang
Keyword(s):  
Surface Force ◽  
Element Model ◽  
Adhesive Contact ◽  
Work Of Adhesion ◽  
Loading Path ◽  
Transfer Printing ◽  
Adhesive Interaction ◽  
Pdms Stamp ◽  
Thermodynamic Work ◽  
Thermodynamic Work Of Adhesion

Microtransfer printing is a sophisticated technique for the heterogeneous integration of separately fabricated micro/nano-elements into functional systems by virtue of an elastomeric stamp. One important factor influencing the capability of this technique depends on the adhesion between the viscoelastic stamp and the transferred element. To provide theoretical guidance for the control of adhesion in the transfer printing process, a finite element model for the viscoelastic adhesive contact between a polydimethylsiloxane (PDMS) stamp and a spherical transferred element was established, in which the adhesive interaction was modeled by the Lennard-Jones surface force law. Effects of the unloading velocity, preload, and thermodynamic work of adhesion on the adhesion strength, characterized by the pull-off force, were examined for a loading-dwelling-unloading history. Simulation results showed that the unloading path deviated from the loading path due to the viscoelastic property of the PDMS stamp. The pull-off force increased with the unloading velocity, and the increasing ratio was large at first and then became low. Furthermore, the influence of the preload on increasing the pull-off force was more significant under larger unloading velocity than that under smaller unloading velocity. In addition, the pull-off force increased remarkably with the thermodynamic work of adhesion at a fixed maximum approach.

The Effect of Environment on Adhesion of Shrink-Resist Polymers on Wool

1976 ◽  
Vol 46 (11) ◽  
pp. 796-801 ◽  
Author(s):  
Brett O. Bateup ◽  
John R. Cook ◽  
H. Douglas Feldtman ◽  
Barry E. Fleischfresser
Keyword(s):  
Surface Tension ◽  
Adhesive Joints ◽  
Work Of Adhesion ◽  
Polymer Interface ◽  
Thermodynamic Work ◽  
Polymer Adhesive ◽  
Thermodynamic Work Of Adhesion ◽  
Secondary Bonding

The durability of wool/polymer adhesive Joints in wash liquors of different surface tension was determined by measuring the rate of felting shrinkage of polymer-treated wool sliver and fabric in each liquor. The rate of felting shrinkage increased as the surface tension of the liquor decreased. This trend in the rate of felting shrinkage of polymer-treated wool agreed well with the trend in the magnitude of the thermodynamic work of adhesion of a wool/polymer “adhint” in different liquids, calculated assuming only secondary bonding forces across the wool/polymer interface. Limitations of the theory are discussed

Thermochemistry and electrical contact properties at the interface between semiconducting BaTiO3 and (Au–Ti) electrodes

1997 ◽  
Vol 12 (7) ◽  
pp. 1685-1688 ◽  
Author(s):  
David P. Cann ◽  
Clive A. Randall
Keyword(s):  
Contact Resistance ◽  
Sessile Drop ◽  
Electrical Contact ◽  
Positive Temperature Coefficient ◽  
Work Of Adhesion ◽  
Positive Temperature ◽  
Temperature Coefficient Of Resistance ◽  
Thermodynamic Work ◽  
Thermodynamic Work Of Adhesion ◽  
Electrode Metal

The interfacial characteristics of positive temperature coefficient of resistance (PTCR) BaTiO3-electrode interfaces were studied. Sessile drop wetting experiments in combination with measurements of the contact resistance of the interface were used to establish a fundamental perspective of the electrode-ceramic interface. It was shown that the thermodynamic work of adhesion Wad), which is the sum of the strengths of chemical interactions present at the interface, can be manipulated by the addition of chemically active elements to the electrode metal which enhance adhesion. This same procedure is shown to modify the important electrical interfacial properties such as the contact resistance.

scholarly journals Composite material based on the polyethylene terephthalate polymer and modified fly ash filler

2018 ◽  
Vol 245 ◽  
pp. 03007
Author(s):  
Nikolai Zaichenko ◽  
Vladislav Nefedov
Keyword(s):  
Composite Material ◽  
Fly Ash ◽  
Polyethylene Terephthalate ◽  
High Performance ◽  
Polymer Composite Material ◽  
Work Of Adhesion ◽  
Thermodynamic Work ◽  
High Adhesion ◽  
Thermodynamic Work Of Adhesion ◽  
Key Parameter

The possibility of filling the recycled polyethylene terephthalate (rPET) with fly ash was studied to make a polymer composite material (PCM). It is shown that high adhesion between polymeric matrix and mineral filler is the key parameter to produce high performance PCM. For this purpose the acid-basic interaction as well as the thermodynamic work of adhesion between components of PCM were calculated. The technique of modifying fly ash filler with 5% concentration solution of sulfuric acid to increase acid-basic interaction has been elaborated. The resulting behavioral patterns are listed and compared to those of composites containing untreated fly ash particles.

On Relating Thermodynamic Work of Adhesion to Interfacial Fracture Toughness

1996 ◽  
Vol 445 ◽  
Author(s):  
Raymond A. Pearson ◽  
Thomas B. Lloyd
Keyword(s):  
Fracture Toughness ◽  
Strain Energy Release ◽  
Interfacial Fracture ◽  
Work Of Adhesion ◽  
Interfacial Fracture Toughness ◽  
Package Design ◽  
Silicon Chips ◽  
Interfacial Fracture Mechanics ◽  
Thermodynamic Work ◽  
Thermodynamic Work Of Adhesion

AbstractOrganic adhesives are commonly used in the microelectronics industry to bond silicon chips to a wide variety of substrates. The substrates include copper, silver, nickel / palladium, polyimide, and glass‐filled epoxies. The surfaces of these substrates are affected by the processing steps used in the manufacturing process used to produce the final package. The most common adhesives used in the assembly of microelectronic packages are epoxy‐based and there are numerous grades and types to chose from. Therefore, the packaging engineer is faced with the dilemma of what criterion to use to select the best adhesive for a particular package design.At the crux of the problem is how does one predict adhesion and how does one measure it? It is proposed that the surfaces play an important role in forming the interfacial bond and that strength of the mating surfaces can be characterized in terms of the thermodynamic work of adhesion. Roughness is also a factor but will not be dealt with here. The thermodynamic work of adhesion describes the energy to reversibly separate two surfaces (elastic). Interfacial fracture mechanics may be used to quantify the strain energy release rate for separating two surfaces and contains both elastic and inelastic contributions. This talk will contain a discussion of our studies on the use of a three liquid probe method to determine the thermodynamic work of adhesion and a mixed‐mode bending method to measure interfacial fracture toughness. Moreover, we will comment on the perils of relating the thermodynamic work of adhesion to the interfacial fracture toughness.

A Continuum Mechanics Model of Adhesive Contact Based on the Lennard-Jones Potential

2010 ◽  
Author(s):  
Z. Song ◽  
K. Komvopoulos
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Surface Displacement ◽  
Effective Elastic Modulus ◽  
Element Model ◽  
Adhesive Contact ◽  
Surface Interaction ◽  
Rigid Sphere ◽  
Adhesive Interaction ◽  
Lennard Jones

A continuum model of adhesive interaction between elastic surfaces is presented. Surface interaction between two elastic spheres is modeled by the Lennard-Jones (L-J) potential. The analysis is based on the equivalent system of a rigid sphere of reduced radius in close proximity with an elastic half-space of effective elastic modulus. The critical gap at the instant of the “jump-in” and “jump-out” contact instabilities is determined by an elastic solution of the half-space surface displacement. A finite element model, in which surface interaction is modeled by nonlinear springs of a prescribed force-displacement governed by the L-J potential, is also used to analyze adhesive surface interaction. The analytical model is validated by finite element results of the critical central gap at the instant of jumpin and jump-out instabilities for different values of the Tabor parameter.

scholarly journals Adhesion Assessment of Copper Thin Films

1997 ◽  
Vol 473 ◽  
Author(s):  
M. D. Kriese ◽  
N. R. Moody ◽  
W. W. Gerberich
Keyword(s):  
Residual Stress ◽  
Interfacial Adhesion ◽  
Work Of Adhesion ◽  
Copper Films ◽  
Cathode Sputtering ◽  
Interfacial Toughness ◽  
Si Substrates ◽  
Thermodynamic Work ◽  
High Residual Stress ◽  
Thermodynamic Work Of Adhesion

ABSTRACTNano-indentation testing has been used to quantitatively assess the adhesion of thin copper films, sputtered to thicknesses of 150 nm to 1500 nm. Copper films of low residual stress were deposited via RF diode cathode sputtering onto SiO2/Si substrates. Overlayers of DC magnetron sputtered high residual stress tungsten, 850 nm thick, were additionally used to provide a driving force for delamination. All films tested exhibited buckle-driven delamination, from which the interfacial toughness was estimated to be 0.2 – 2 J/m2, which is comparable to the thermodynamic work of adhesion. The use of an overlayer requires extensions of existing models, but otherwise does not change the interfacial adhesion, allowing measurements of films that would not otherwise delaminate.

Quantitative adhesion measures of multilayer films: Part II. Indentation of W/Cu, W/W, Cr/W

1999 ◽  
Vol 14 (7) ◽  
pp. 3019-3026 ◽  
Author(s):  
Michael D. Kriese ◽  
William W. Gerberich ◽  
Neville R. Moody
Keyword(s):  
Quantitative Measure ◽  
Multilayer Films ◽  
Adhesion Energy ◽  
Work Of Adhesion ◽  
Copper Films ◽  
Residual Tension ◽  
Thermodynamic Work ◽  
Film Adhesion ◽  
Thin Film Adhesion ◽  
Thermodynamic Work Of Adhesion

Sputtered copper and tungsten thin films both with and without tungsten and chromium superlayers were tested by using nanoindentation probing to initiate and drive delamination. The adhesion energies of the films were calculated from the induced delaminations using the analysis presented in “Quantitative adhesion measures of multilayer films: Part I. Indentation mechanics.” Copper films ranging in thickness from 150 to 1500 nm in the as-sputtered condition had measured adhesion energies ranging from 0.2 to 2 J/m2, commensurate with the thermodynamic work of adhesion. Tungsten films ranging in thickness from 500 to 1000 nm in the as-sputtered condition had measured adhesion energies ranging from 5 to 15 J/m2. The superlayer was shown to induce radial cracking when under residual tension, resulting in underestimation of the adhesion energy when the film was well adhered. Under conditions of weak adherence or residual compression, the superlayer provided an excellent means to induce a delamination and allowed an accurate and reasonably precise quantitative measure of thin film adhesion.

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