Mechanical Behaviour of Two Sorts of MCM Structures

1995 ◽  
Vol 390 ◽  
Author(s):  
G. Pozza ◽  
G. Parat ◽  
M. Ignat ◽  
M. Dupeux ◽  
J. M. Terriez
Keyword(s):  
Flip Chip ◽  
Mechanical Response ◽  
Crack Nucleation ◽  
Crack Opening ◽  
Tensile Tests ◽  
Nucleation Site ◽  
In Situ Tests ◽  
Solder Bumps ◽  
Pbsn Solder

ABSTRACTWe analysed the mechanical response of samples, representing Flip-Chip bonded type structures. Two sort of distributions of the PbSn solder bumps, interconecting a chip to a substrate were investigated. The mechanical response was established from macroscopic shear and tensile tests. The microstructural evolution to complete mechanical failure, was observed during similar tests, but performed in a Scanning Electron Microscope. These in-situ tests revealed a preferential crack nucleation site in the samples, specific to one of the interfaces. A complementary numerical analysis was developed, for trying to explain the preferential crack opening site.

In‐Situ Mapping and Modeling Verification of Thermomechanical Deformation in Underfilled Flip‐Chip Packaging Using Moiré Interferometry

1996 ◽  
Vol 445 ◽  
Author(s):  
Xiang Dai ◽  
Connie Kim ◽  
Ralf Willecke ◽  
Paul S. Ho
Keyword(s):  
Flip Chip ◽  
Thermal Loading ◽  
Deformation Monitoring ◽  
Moiré Interferometry ◽  
Moire Interferometry ◽  
Fringe Analysis ◽  
Element Analysis ◽  
Solder Bumps ◽  
Thermomechanical Deformation

AbstractAn experimental technique of environmental moiré interferometry has been developed for in‐situ monitoring and analysis of thermomechanical deformation of microelectronics packages subjected to thermal loading under a controlled atmosphere. Coupled with fractional fringe analysis and digital image processing, the environmental moiré interferometry technique achieves accurate and realistic deformation monitoring with high sensitivity and excellent spatial resolution. It has been applied to investigate the thermomechanical deformations induced by thermal loading in an underfilled flip‐chip‐on‐board packaging. The effects of temperature change in the range of 102 °C to 22 °C are analyzed for underfill and solder bumps. In addition, shear deformation and shear strains across the solder bumps are determined as a function of temperature. The experimental results are compared with the results of a finite element analysis for modeling verification. Good agreement between the modeling results and experimental measurements has been found in the overall displacement fields. Through this study, the role of underfill in the thermomechanical deformation of the underfilled flip‐chip package is determined.

Investigation of Plastic Instability in TWIP Steels by In Situ Diffraction of High Energy X-Rays

2014 ◽  
Vol 783-786 ◽  
pp. 1105-1110
Author(s):  
Jean Philippe Chateau-Cornu ◽  
Alain Jacques ◽  
Jean Philippe Tinnes ◽  
Thomas Schenk
Keyword(s):  
Plastic Strain ◽  
Elastic Anisotropy ◽  
Tensile Tests ◽  
Plastic Instability ◽  
High Energy ◽  
Nucleation Site ◽  
X Rays ◽  
Cubic Crystal ◽  
Twip Steels

We investigate the non uniform plastic deformation of a TWIP FeMnC steel by diffraction of high energy synchrotron X-rays. In particular, we observe the propagation of bands of plastic strain localisation. Debye-Scherrer rings are recorded in situ during tensile tests at two different strain rates. Discontinuous initial rings characteristic of unstrained polycristals with no texture become rapidly continuous after several percents of plastic strain due to strain gradients within the grains and a strong texture develops. The crystallographic dependence of the Young’s modulus is estimated and is consistent with the elastic anisotropy of a cubic crystal. A delay between the serrations on the macroscopic tensile curve and the stepwise variations of the diffracted peak’s position and width are consistent with propagating bands nucleating outside the X-ray beam. Slower and thinner bands are observed at the lowest strain rate. A tensile test interrupted to perform a few minute relaxation leads to a displacement of the nucleation site of the bands from one end to the middle of the gauge part.

Detection of the Fracture Path under Tensile Loads through in situ Tests in an ESEM Chamber

Holzforschung ◽  
2003 ◽  
Vol 57 (3) ◽  
pp. 326-332 ◽  
Author(s):  
K. Frühmann ◽  
I. Burgert ◽  
S. E. Stanzl-Tschegg
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Tensile Tests ◽  
Specimen Size ◽  
Environmental Scanning ◽  
Fracture Path ◽  
Cooling Device ◽  
In Situ Tests ◽  
Scanning Electron

Summary In situ tensile tests parallel to the grain were carried out in an Environmental Scanning Electron Microscope (ESEM) chamber on Norway spruce (Picea abies [L.] Karst.) samples. The ESEM-mode combined with a cooling device allowed examination of the specimens at a moisture content of 12% with unsputtered surfaces. By recording load-displacement curves and observing crack propagation simultaneously, a detailed image of fracture progress and tissue interaction could be described. Since these experiments required a sufficient specimen size and geometry, focus was concentrated on the methodology.

scholarly journals Study of Elastic Behavior of Metallic Thin Films by 2D Synchrotron XRD and in situ Tensile Testing

2007 ◽  
Vol 1027 ◽  
Author(s):  
Geandier Guillaume ◽  
Renault Pierre-Olivier ◽  
Goudeau Philippe ◽  
Eric Le Bourhis ◽  
Girault Baptiste
Keyword(s):  
Thin Films ◽  
Mechanical Response ◽  
Tensile Tests ◽  
Elastic Behavior ◽  
Metallic Thin Films ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
X Ray ◽  
Transmission Geometry

AbstractUnderstanding the mechanical behaviour of nano-structured thin films in relation to their structure, in particular to the grain size, is of high importance for the development of technological applications. Model nanometric multilayer W/Au systems exhibiting different structures are elaborated. These films are supported by a (thin) polyimide substrate. Films mechanical response is characterized experimentally by tensile tests carried out in-situ in a X-ray diffractometer installed on a synchrotron source. X-ray diffraction in transmission geometry has been used to study the deformations of both phases as a function of applied load. This geometry has been developed in the aim of optimizing the experiment time.

Deformation and Strain Measurement of Flip-Chip Solder Bump Under In-Situ Thermal Loading

2009 ◽  
Author(s):  
Jae B. Kwak ◽  
Dong Gun Lee ◽  
Tung Nguyen ◽  
Seungbae Park
Keyword(s):  
Deformation Behavior ◽  
Flip Chip ◽  
Thermal Loading ◽  
Solder Bump ◽  
Solder Joints ◽  
Image Correlation ◽  
Solder Bumps ◽  
Comparison Results ◽  
Dic Technique

Thermo-mechanical behavior of solder joints, especially the solder bumps located at the chip corners where most failures usually occur was investigated. Digital Image Correlation (DIC) technique with optical microscope was adopted to quantify the deformation behavior and strains of a solder bump of flip-chip package subjected to thermal loading. A flip-chip specimen was cross-sectioned after manual polishing process followed by wet etching method in order to generate natural speckle patterns with high enough contrast on the measuring surface for employing DIC technique. The sample was placed in a miniature heating chamber and subjected to in-situ thermal loading from 25 °C to 100°C. During the heating, sequential microscopic images of the cross-sectioned surface of a solder bump were acquired, and the deformation behavior and strain distributions were successfully measured with submicron accuracy by applying DIC technique on the captured images. The computed full-field displacement fields clearly depicted both normal and shear deformation of the solder bump under the thermal loading. In addition, from the strain fields, it was observed that strains were mostly concentrated on the bottom portion of solder bump near the pad connected to substrate. In order to assess the thermo-mechanical strains of the flip-chip interconnections more quantitatively, the average strains of solder joints at different locations were also measured and compared to one another. By doing so, the strain trends of solder bumps were effectively analyzed with respect to the distance to neutral point (DNP). Finally, finite element analysis was conducted by simulating the thermal loading applied in the experiments, and comparison between the simulation and experimental results of displacements and strains was made. The comparison results exhibited satisfactory agreement, which ensured the validity of the experimental data and methodology. This study can further expedite the studies of electronic-package reliability through fatigue and crack failure analysis of the solder joints due to thermal cyclic loading.

Study of the undercooling of Pb-free, flip-chip solder bumps and in situ observation of solidification process

2007 ◽  
Vol 22 (3) ◽  
pp. 557-560 ◽  
Author(s):  
Sung K. Kang ◽  
M.G. Cho ◽  
P. Lauro ◽  
Da-Yuan Shih
Keyword(s):  
Flip Chip ◽  
Solidification Process ◽  
In Situ Observation ◽  
Imaging Method ◽  
Scanning Calorimetry ◽  
Solder Bumps ◽  
Chip Size ◽  
Free Solder ◽  
Heating Up

The undercooling of flip-chip Pb-free solder bumps was investigated by differential scanning calorimetry (DSC) to understand the effects of solder composition and volume, with and without the presence of an under bump metallurgy (UBM). A large amount of the undercooling (as large as 90 °C) was observed with Sn-rich, flip-chip size solder bumps sitting in a glass mold, while the corresponding undercooling was significantly reduced in the presence of a wettable UBM surface. In addition, the solidification of an array of individual solder bumps was monitored in situ by a video imaging technique during both heating-up and cooling-down cycles. Data obtained by the optical imaging method were used to complement the DSC thermal measurements. A random solidification of the array of bumps was demonstrated during cooling, which also spans a wide temperature range of 40–80 °C. In contrast, an almost simultaneous melting of the bumps was observed during heating.

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