LED Chip Deformation Measurement During the Operation Using the X-Ray CT Digital Volume Correlation

2015 ◽  
Author(s):  
Pradeep Lall ◽  
Junchao Wei
Keyword(s):  
Three Dimensional ◽  
Ct Scanning ◽  
Image Correlation ◽  
Reference Image ◽  
Digital Volume Correlation ◽  
X Ray ◽  
Function Computation ◽  
Fixed Subset ◽  
Three Dimensional Measurement ◽  
Strain Components

A high-power LED can generate tremendous heat under the operation, which causes the LED chip undergo large deformation. LED Wire Bonds may undergo deformation because of the mismatch between the LED chip and substrate. Presently, measurements of deformation and strain in operational electronics are limited to measurement on a cut-plane using techniques including digital image correlation and moiré interferometry based techniques. There is need for tools and techniques that can help quantify the in-situ chip deformation and interconnects inside the LED. Digital Volume Correlation (DVC) has been used in conjunction with X-ray Micro-CT for three-dimensional measurement of deformation and strain in LEDs under operational stresses. The Digital Volume Correlation has been used to correlate the undeformed image with deformed images by computing correlation functions throughout each voxel. The deformed images have been generated by CT scanning over the object while the LED is operational. The correlation function computation starts at specific fixed subset window in the reference image, and searches every possible subset window in the deformed image to identify the deformation in the electronic structure. Once the displacement components have been derived, the strain components have been computed by calculating the gradients of the displacement field. In this paper, the full strain field, both in-plane and out-plane strain, will be presented, and the LED chip deformation shape will be analyzed.

scholarly journals 3D Studies of Indentation by Combined X-Ray Tomography and Digital Volume Correlation

2013 ◽  
Vol 592-593 ◽  
pp. 14-21 ◽  
Author(s):  
Mahmoud Mostafavi ◽  
Yelena Vertyagina ◽  
Christina Reinhard ◽  
Robert Bradley ◽  
Xia Jiang ◽  
...  
Keyword(s):  
Crack Opening ◽  
Three Dimensional ◽  
Image Correlation ◽  
Digital Volume Correlation ◽  
Surface Characterisation ◽  
X Ray ◽  
Element Simulation ◽  
Potential Applications ◽  
Deformation Processes ◽  
X Ray Computed

Hardness testing obtains material properties from small specimens via measurement of load-displacement response to an imposed indentation; it is a surface characterisation technique so, except in optically transparent materials, there is no direct observation of the assumed damage and deformation processes within the material. Three-dimensional digital image correlation (digital volume correlation) is applied to study deformation beneath indentations, mapping the relative displacements between high-resolution synchrotron X-ray computed tomographs (0.9 μm voxel size). Two classes of material are examined: ductile aluminium-silicon carbide composite (Al-SiC) and brittle alumina (Al2O3). The measured displacements for Hertzian indentation in Al-SiC are in good agreement with an elastic-plastic finite element simulation. In alumina, radial cracking is observed beneath a Vickers indentation and the crack opening displacements are measured, in situ under load, for the first time. Potential applications are discussed of this characterization technique, which does not require resolution of microstructural features.

scholarly journals Digital Volume Correlation Applied to X-ray Micro-Tomography Images in Uniaxial Creep Tests on Anisotropic Clayey Rock

2020 ◽  
Vol 10 (14) ◽  
pp. 4898
Author(s):  
Hailing Shi ◽  
Jerome Hosdez ◽  
Thomas Rougelot ◽  
Shouyi Xie ◽  
Jianfu Shao ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Clayey Rock ◽  
Digital Volume Correlation ◽  
Creep Tests ◽  
Structural Anisotropy ◽  
Strain Fields ◽  
X Ray ◽  
Bedding Planes ◽  
Uniaxial Creep ◽  
Micro Tomography

Creep tests are commonly performed to characterize time-dependent deformation of geological materials. Classical measuring methods are not suitable for long term tests and not able to provide full three-dimensional strain fields. In this study, Digital Volume Correlation (DVC) is applied to X-ray micro-tomography (XRMT) images from creep tests on a hard clayey rock. In situ uniaxial compression creep tests are performed under different levels of stress and with different loading orientations with respect to the structural anisotropy of rock. Based on the XRMT images taken during the creep tests, DVC is applied to compute the full three dimensional strain fields and global averages strains of tested samples. The effects of bedding planes and hard inclusions on the non-uniform distribution of strains are analyzed.

scholarly journals Reconstruction and Analysis of Tight Sandstone Digital Rock Combined with X-Ray CT Scanning and Multiple-Point Geostatistics Algorithm

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yun Lei
Keyword(s):  
Pore Space ◽  
Full Range ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Multiple Point ◽  
Tight Sandstone ◽  
Sandstone Sample ◽  
X Ray ◽  
Digital Rock ◽  
Experimental Values

Unconventional rocks such as tight sandstone and shale usually develop multiscale complex pore structures, with dimensions ranging from nanometers to millimeters, and the full range can be difficult to characterize for natural samples. In this paper, we developed a new hybrid digital rock construction approach to mimic the pore space of tight sandstone by combining X-ray CT scanning and multiple-point geostatistics algorithm (MPGA). First, a three-dimensional macropore digital rock describing the macroscopic pore structure of tight sandstone was constructed by micro-CT scanning. Then, high-resolution scanning electron microscopy (SEM) was performed on the tight sandstone sample, and the three-dimensional micropore digital rock was reconstructed by MPGA. Finally, the macropore digital rock and the micropore digital rock were superimposed into the full-pore digital rock. In addition, the nuclear magnetic resonance (NMR) response of digital rocks is simulated using a random walk method, and seepage simulation was performed by the lattice Boltzmann method (LBM). The results show that the full-pore digital rock has the same anisotropy and good connectivity as the actual rock. The porosity, NMR response, and permeability are in good agreement with the experimental values.

scholarly journals Three-Dimensional Investigation of Free-Edge Effects in Laminate Composites Using X-ray Tomography and Digital Volume Correlation

2014 ◽  
Vol 55 (1) ◽  
pp. 301-311 ◽  
Author(s):  
P. Lecomte-Grosbras ◽  
J. Réthoré ◽  
N. Limodin ◽  
J.-F. Witz ◽  
M. Brieu
Keyword(s):  
Edge Effects ◽  
Three Dimensional ◽  
Free Edge ◽  
Digital Volume Correlation ◽  
Laminate Composites ◽  
X Ray

A DIGITAL VOLUME CORRELATION TECHNIQUE FOR 3-D DEFORMATION MEASUREMENTS OF SOFT GELS

2011 ◽  
Vol 03 (02) ◽  
pp. 335-354 ◽  
Author(s):  
JIANYONG HUANG ◽  
XIAOCHANG PAN ◽  
SHANSHAN LI ◽  
XIAOLING PENG ◽  
CHUNYANG XIONG ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Image Correlation ◽  
Digital Volume Correlation ◽  
Correlation Technique ◽  
Strain Fields ◽  
Measurement Capability ◽  
Soft Gels ◽  
Deformation Measurements

This paper develops a set of digital volume correlation (DVC) algorithms to address 3-D deformation measurements of soft gels with the aid of laser-scanning confocal microscopy. As an extension of the well-developed digital image correlation (DIC) method, the present DVC approach adopts a three-dimensional zero-normalized cross-correlation criterion (3-D ZNCC) to perform volume correlation calculations. Based on a 3-D sum-table scheme and the fast Fourier transform technique, a fast algorithm is first proposed to accelerate the integer-voxel correlation computations. Subsequently, two kinds of sub-voxel registration algorithms, i.e., 3-D gradient-based algorithm and 3-D Newton–Raphson algorithm, are presented to obtain the sub-voxel displacement and strain fields of volume images before and after deformation. Both a series of computer-simulated digital volume images and an actual agarose gel sample randomly embedded with fluorescent particles are employed to verify the 3-D deformation measurement capability of the proposed DVC algorithms, which indicates that they are competent to acquire 3-D displacement and strain fields of soft gels.

scholarly journals High-throughput three-dimensional visualization of root system architecture of rice using X-ray computed tomography

2020 ◽  
Author(s):  
Shota Teramoto ◽  
Satoko Takayasu ◽  
Yuka Kitomi ◽  
Yumiko Arai-Sanoh ◽  
Takanari Tanabata ◽  
...  
Keyword(s):  
High Throughput ◽  
System Architecture ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Root System Architecture ◽  
Visualization Method ◽  
Process Flow ◽  
X Ray ◽  
X Ray Computed ◽  
Crown Roots

Abstract Background: X-ray computed tomography (CT) allows us to visualize root system architecture (RSA) beneath the soil, non-destructively and in a three-dimensional (3-D) form. However, CT scanning, reconstruction processes, and root isolation from X-ray CT volumes, take considerable time. For genetic analyses, such as quantitative trait locus mapping, which require a large population size, a high-throughput RSA visualization method is required. Results: We have developed a high-throughput process flow for the 3-D visualization of rice (Oryza sativa) RSA (consisting of radicle and crown roots), using X-ray CT. The process flow includes use of a uniform particle size, calcined clay to reduce the possibility of visualizing non-root segments, use of a higher tube voltage and current in the X-ray CT scanning to increase root-to-soil contrast, and use of a 3-D median filter and edge detection algorithm to isolate root segments. Using high-performance computing technology, this analysis flow requires only 10 min (33 s, if a rough image is acceptable) for CT scanning and reconstruction, and 2 min for image processing, to visualize rice RSA. This reduced time allowed us to conduct the genetic analysis associated with 3-D RSA phenotyping. In 2-week-old seedlings, 85% and 100% of radicle and crown roots were detected, when 16 cm and 20 cm diameter pots were used, respectively. The X-ray dose per scan was estimated at < 0.09 Gy, which did not impede rice growth. Using the developed process flow, we were able to follow daily RSA development, i.e., 4-D RSA development, of an upland rice variety, over three weeks. Conclusions: We developed a high-throughput process flow for 3-D rice RSA visualization by X-ray CT. The X-ray dose assay on plant growth has shown that this methodology could be applicable for 4-D RSA phenotyping. We named the RSA visualization method ‘RSAvis3D’ and are confident that it represents a potentially efficient application for 3-D RSA phenotyping of various plant species.

scholarly journals A new seahorse (Teleostei: Syngnathidae: Hippocampus) from south-western Australia

Zootaxa ◽  
2010 ◽  
Vol 2613 (1) ◽  
pp. 61 ◽  
Author(s):  
RALPH FOSTER ◽  
MARTIN F. GOMON
Keyword(s):  
New Species ◽  
Soft Tissue ◽  
Continental Shelf ◽  
Western Australia ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Dorsal Midline ◽  
X Ray ◽  
Dorsal Fin ◽  
A New Species

A new species of syngnathid fish, Hippocampus paradoxus sp. nov., from mid-continental shelf waters of south-western Australia is described from the only known specimen. It can be distinguished from all congeners, including the very similar H. minotaur Gomon 1997, by the following features: the lack of a dorsal fin, a series of fleshy, fin-like lobes along the dorsal midline of the trunk and tail and an extremely robust cleithrum and prominent first nuchal plate. In addition to the traditional methods of syngnathid taxonomists, X-ray microtomography (CT scanning) was employed and demonstrated to be a valuable research tool for examining seahorse species that are problematic due to reduced ossification and small size. CT scanning is more capable of imaging poorly ossified and soft tissue regions than traditional radiography and provides a detailed three dimensional view of salient features.

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