Allen Gu

Multi-scale method of Nano(Micro)-CT study on microscopic pore structure of tight sandstone of Yanchang Formation, Ordos Basin

Abstract Multi-scale (nano-to-micro) three-dimensional CT imaging was used to characterize the distribution and texture of micro-scale pore throats in tight sandstone reservoirs of the Triassic Yanchang Formation, Ordos Basin. First, the low-resolution Micro-CT was used to reflect the micro-pore texture of the core column with a diameter of 2.54 cm. Then, some samples with a diameter of 65 μm was derived from different areas according the different characteristics of micro-pore texture of the core scanned by low-resolution Micro-CT and scanned by high-resolution Nano-CT. Thus, a three-dimensional texture model of nano-scale micro-pores was reestablished and the permebility and porosity data of the sample could be obtained. On a micrometer scale, the size of the micro-pores varies, and their diameters range from 5.4 to 26.0 μm. The micro-pores are isolated, locally in the shape of a band. On a nanometer scale, the quantity of nanoscale micropores increases, the diameter of which ranges from 0.4 to 1.5 μm. The pore throats are arranged in the shape of tube and ball inside or on the surface of mineral particles(crystals). The ball-shaped micropores in nanoscale, often isolated in the three-dimensional space, show the poor connectivity and consequently act as the reservoir space. By contrast, the tube-shaped micropores in nanoscale show certain connectivity with micro-scale tube-shaped micropores and adjacent isolated ball-shaped micropores in nanoscale. Therefore, these tube-shaped micropores in nanoscale serve as throats and pores. Based on the calcution, the permeability of the samples is 0.843×10 −3 μm 2 and porosity is 10%.

High resolution 3D X-ray microscopy for streamlined failure analysis workflow

High resolution 3D X-ray microscopy is a powerful non-destructive technology to inspect internal failure of IC packages. Here we present a correlative workflow by combining thermal emission microscopy, high resolution 3D X-ray microscopy and dual-beam focused ion beam microscopy to analyze a failed FCBGA package.

X-ray microscopy for in situ characterization of 3D nanostructural evolution in the laboratory

X-ray microscopy (XRM) has emerged as a powerful technique that reveals 3D images and quantitative information of interior structures. XRM executed both in the laboratory and at the synchrotron have demonstrated critical analysis and materials characterization on meso-, micro-, and nanoscales, with spatial resolution down to 50 nm in laboratory systems. The non-destructive nature of X-rays has made the technique widely appealing, with potential for “4D” characterization, delivering 3D micro- and nanostructural information on the same sample as a function of sequential processing or experimental conditions. Understanding volumetric and nanostructural changes, such as solid deformation, pore evolution, and crack propagation are fundamental to understanding how materials form, deform, and perform. We will present recent instrumentation developments in laboratory based XRM including a novel in situ nanomechanical testing stage. These developments bridge the gap between existing in situ stages for micro scale XRM, and SEM/TEM techniques that offer nanometer resolution but are limited to analysis of surfaces or extremely thin samples whose behavior is strongly influenced by surface effects. Several applications will be presented including 3D-characterization and in situ mechanical testing of polymers, metal alloys, composites and biomaterials. They span multiple length scales from the micro- to the nanoscale and different mechanical testing modes such as compression, indentation and tension.

High-res 3D X-ray microscopy for non-destructive failure analysis of chip-to-chip micro-bump interconnects in stacked die packages

Novel 3D architecture of electronics packages raises immense challenges for electrical fault isolation and physical failure analysis (PFA). This paper describes a streamlined workflow involving 3D X-ray Microscopy (XRM) to effectively bridge fault isolation and physical failure analysis (PFA). The case studies on chip-to-chip micro-bump interconnecting failure will be discussed. X-ray microscopy improved the efficiency and efficacy of failure analysis (FA) by non-destructively imaging and analyzing the defects, which was impossible for traditional faulty isolation techniques.

Advanced metrology and inspection solutions for a 3D world

Semiconductor devices and packages have firmly moved in to an era where scaling is driven by 3D architectures. However, most of the metrology and inspection technologies in use today were developed for 2D devices and are inadequate to deal with 3D structures. An additional complication is the need for specific structural and defect information that may be buried deep within a 3D structure. We present concepts and technologies that allow for 3D imaging as well as tomography, enabling engineers to view structural information with unprecedented clarity, detail and speed.

Metrology and Inspection

Spectroscopic reflectometry is a nondestructive technique widely used to analyze the properties of materials as thin layer thicknesses are used in advanced packaging manufacturing. The technique is based on the propagation of waves into media. If a discontinuity is encountered, a part of its energy is reflected back to the injection point according to the well-known law of reflection. The reflected signal gives useful information about the system and, in particular, thicknesses of thin layers.

NDT of electronic packages, MEMs, sensors and materials in 3D to submicron resolution

There is an explosive growth in advanced 3D stacked packages, MEMs and sensors driven by a variety of applications in consumer electronics, aerospace, automotive and medicine. Accurate 3D analysis of their micro and nanostructures, porosity, defects are crucial to predict and correlate thermal-mechanical properties to reliability, performance and the design of next generation products. While conventional imaging modalities such as optical microscopy, SEM with FIB, AFMs have good resolution, they are limited to surface imaging in 2D and require destructive sample preparation to reveal buried structures. Moreover, precise sample sectioning is proving to be challenging with the advent of 3D stacked packages such as large aspect ratio Through Silicon Via (TSV) where via dimensions can be < 5 um diameter × 50 um long or in combed MEMs structures where the sample cannot be physically sectioned or chemically etched without disturbing the actual construction of the device. Existing NDT (non destructive testing) techniques such as X-ray/Neutron radiography, acoustic, eddy current techniques lack the resolution for micro and nano structural characterization. While conventional microCT or nanoCT (micro x-ray computed tomography) have the advantage to be non destructive and provide 3 D imaging, they suffer from poor resolution and contrast especially with large or thick packages and devices. Since resolution is limited to the spot size of the x-ray source, sample size and sample-source working distance, the resolving power of conventional CT is limited to a few microns at best, to several microns being typical, for most packages and sensors.