scholarly journals A Solder Based Self Assembly Project In An Introductory IC Fabrication Course

2015 ◽  
Vol 6 (1) ◽  
pp. 11-26 ◽  
Author(s):  
Madhav Rao ◽  
John C Lusth ◽  
Susan L Burkett
Keyword(s):  
Integrated Circuit ◽  
Self Assembly ◽  
Semiconductor Industry ◽  
Three Dimensional ◽  
Cost Effective ◽  
Deposition Process ◽  
Design Stage ◽  
Laboratory Course ◽  
Final Project ◽  
Hands On

Integrated circuit (IC) fabrication principles is an elective course in a senior undergraduate and early graduate student’s curriculum. Over the years, the semiconductor industry relies heavily on students with developed expertise in the area of fabrication techniques, learned in an IC fabrication theory and laboratory course. The theory course gives importance to the physics of manufacturing techniques and is often attached to a subsequent semester laboratory curriculum. The pre-requisite requirement of the theory component for a laboratory course requires students to enroll for two courses in separate semesters and is not an option for all students. Hence, an innovative student project is intended in the theory curriculum to give hands-on experience on the processes. The IC fabrication course is usually associated with high enrollment of students, leading to fewer laboratory experiments. The physics of IC fabrication techniques is important, but few students may perceive the theory as important with no laboratory experience. To improve the course and give students hands-on practice with existing state-of-the-art processing facilities, a tailored project was added to the syllabus. A solder-based self assembly (SBSA) project was introduced in the curriculum for the first time at the University of Alabama in Fall 2011. The student projects were designed in a way to provide an alternative to conventional time-intensive, high cost, and highly tool dependent IC fabrication lab experiments. SBSA forms three dimensional (3D) structures when applied to two dimensional (2D) patterns. The schedule was designed to accommodate theory classes aligned with the fabrication steps and completed by students. The project involved a brainstorming session, a design stage to develop 2D patterns using AutoCAD software, a deposition process, a lithography step, a dip soldering step, a reflow process, scanning electron microscope (SEM) imaging, and a final project presentation. Other processes required to complete the project were performed by the instructor. In general, students showed interest in working in teams, completing the project, and recommended to continuing the SBSA project in future IC fabrication course work. The SBSA project is cost effective and less tool dependent for incorporation in a semester long course. In addition, the project is time effective from both student and instructor perspectives. 

Molding of Three-Dimensional Microcomponents

2006 ◽  
Author(s):  
W. N. P. Hung ◽  
M. M. Agnihotri ◽  
M. Y. Ali ◽  
S. Yuan
Keyword(s):  
Focused Ion Beam ◽  
New Technologies ◽  
Electrical Discharge Machining ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Three Dimensional ◽  
Cost Effective ◽  
Molecular Structures ◽  
Minimum Size ◽  
Ion Beam Sputtering

Traditional micromanufacturing has been developed for semiconductor industry. Selected micro electrical mechanical systems (MEMS) have been successfully developed and implemented in industry. Since current MEMS are designed for manufacture using microelectronics processes, they are limited to two-dimensional profiles and semiconductor based materials. Such shape and material constraints would exclude many applications that require biocompatibility, dynamic stress, and high ductility. New technologies are sought to fabricate three dimensional microcomponents using robust materials for demanding applications. To be cost effective, such microdevices must be economically mass producible. Molding is one of the promising replication techniques to mass produce components from polymers and polymer-based composites. This paper presents the development of a micromolding process to produce thermoplastic microcomponents. Mold design required precision fitting and was integrated with a vacuum pump to minimize air trap in mold cavities. Nickel and aluminum mold inserts were used for the study; their cavities were fabricated by combinations of available micromachining processes like laser micromachining, micromilling, micro electrical discharge machining, and focused ion beam sputtering. High and low density polyethylene, polystyrene polymers were used for this study. The effects of polymer molecular structures, molding temperature, time, and pressure on molding results were studied. Simulation of stress in the microcomponents, plastic flow in microchannels, and mold defects was performed and compare with experimental data. The research results showed that a microcomponent can be fabricated to the minimum size of 10 ± 1μm (0.0004 inch) with surface roughness <10 nm Rt. Molding of micro-size geartrains and orthopedic meso-size fasteners was completed to illustrate the capability of this process.

Reliable Design of TSV in Free-Standing Wafers and 3D Integrated Packages

2011 ◽  
Author(s):  
Xi Liu ◽  
Margaret Simmons-Matthews ◽  
Kurt P. Wachtler ◽  
Suresh K. Sitaraman
Keyword(s):  
Integrated Circuit ◽  
Mechanical Performance ◽  
Semiconductor Industry ◽  
Three Dimensional ◽  
Wafer Level ◽  
Free Standing ◽  
Design Factor ◽  
Reliable Design ◽  
Reliability Issue ◽  
Key Enabling Technologies

Through-silicon via (TSV), being one of the key enabling technologies for three dimensional (3D) Integrated Circuit (IC) stacking, silicon interposer technology, and advanced wafer level packaging (WLP), has attracted tremendous interest throughout the semiconductor industry. However, limited work addresses TSV reliability issue, and most of the existing reliability studies focus on the thermo-mechanical performance of TSVs in a free-standing wafer, rather than in an integrated package. In this paper, three-dimensional thermomechanical Finite-Element (FE) models with TSVs in both free-standing wafers and 3D integrated packages have been built and analyzed. In addition, Design of Experiments (DOE) based approach has been used to understand the effect of various parameters. Results show that the selection of underfill materials between stacked dies is the most dominating design factor for TSV/microbump reliability.

Fabrication of 3D-IC Interposers

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 001295-001321
Author(s):  
John T. Keech ◽  
Garret Piech ◽  
Scott Pollard
Keyword(s):  
Integrated Circuit ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensional ◽  
Cost Savings ◽  
Cost Effective ◽  
Quality Parameters ◽  
Substrate Material ◽  
3D Ic ◽  
And Performance ◽  
Three Dimensional Integrated Circuit

Interposer fabrication has gained a lot of attention in the area of three-dimensional integrated circuit (3D-IC) integration. Glass has many properties that make it well suited for interposer substrates, such as adjustable coefficient of thermal expansion, advantaged electrical properties and unique forming processes. Furthermore, glass based solutions can also provide significant cost advantages in substrate material, via formation, and subsequent processing. In this paper, we will cover how fusion formed glass provides cost-effective solutions for the manufacturing of interposer substrates. Leveraging the ability to create through-glass-via (TGV) substrates in as-formed 100 μm thick precision glass, with a pristine surface, can avoid the need for back grinding and polishing operations. This has the potential to eliminate several manufacturing steps for polishing and thinning, while providing associated cost savings. Significant progress has been made in demonstration of TGV technology. Fully populated wafers with 100,000s of through or blind holes (≥ 25 μm diameter) are fabricated today, and 10–20 μm diameters are in development. We will report on important quality parameters measured on TGV wafers and positive implications with respect to product quality and strength. The ability to leverage industry metallization techniques and performance characteristics will also be reported. Finally, we will discuss opportunities to leverage cost-effective glass interposer solutions.

scholarly journals Simple Self-Assembly Strategy of Nanospheres on 3D Substrate and Its Application for Enhanced Textured Silicon Solar Cell

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2581
Author(s):  
Dan Su ◽  
Lei Lv ◽  
Yi Yang ◽  
Huan-Li Zhou ◽  
Sami Iqbal ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Performance ◽  
Light Trapping ◽  
Incident Light ◽  
Three Dimensional ◽  
Cost Effective ◽  
Optical Measurements ◽  
Sio2 Coating ◽  
Assembly Strategy ◽  
Cost Effective Approach

Nanomaterials and nanostructures provide new opportunities to achieve high-performance optical and optoelectronic devices. Three-dimensional (3D) surfaces commonly exist in those devices (such as light-trapping structures or intrinsic grains), and here, we propose requests for nanoscale control over nanostructures on 3D substrates. In this paper, a simple self-assembly strategy of nanospheres for 3D substrates is demonstrated, featuring controllable density (from sparse to close-packed) and controllable layer (from a monolayer to multi-layers). Taking the assembly of wavelength-scale SiO2 nanospheres as an example, it has been found that textured 3D substrate promotes close-packed SiO2 spheres compared to the planar substrate. Distribution density and layers of SiO2 coating can be well controlled by tuning the assembly time and repeating the assembly process. With such a versatile strategy, the enhancement effects of SiO2 coating on textured silicon solar cells were systematically examined by varying assembly conditions. It was found that the close-packed SiO2 monolayer yielded a maximum relative efficiency enhancement of 9.35%. Combining simulation and macro/micro optical measurements, we attributed the enhancement to the nanosphere-induced concentration and anti-reflection of incident light. The proposed self-assembly strategy provides a facile and cost-effective approach for engineering nanomaterials at 3D interfaces.

Non-Destructive 3D Failure Analysis Work Flow for Electrical Failure Analysis in Complex 2.5D-Based Devices Combining 3D Magnetic Field Imaging and 3D X-Ray Microscopy

2018 ◽  
Author(s):  
Antonio Orozco ◽  
Elena Talanova ◽  
Alex Jeffers ◽  
Florencia Rusli ◽  
Bernice Zee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Failure Analysis ◽  
Integrated Circuit ◽  
Semiconductor Industry ◽  
Three Dimensional ◽  
X Ray ◽  
Electrical Failure ◽  
Magnetic Field Imaging ◽  
3D Stacking ◽  
Field Imaging

Abstract Industry and market requirements keep imposing demands in terms of tighter transistor packing, die and component real estate management on the package, faster connections and expanding functionality. This has forced the semiconductor industry to look for novel packaging approaches to allow for 3D stacking of transistors (the so called “More than Moore”). This complex 3D geometry, with an abundance of opaque layers and interconnects, presents a great challenge for failure analysis (FA). Three-dimensional (3D) magnetic field imaging (MFI) has proven to be a natural, useful technique for non-destructively mapping 3D current paths in devices that allows for submicron vertical resolution. 3D X-ray microscopy (XRM) enables 3D tomographic imaging of advanced IC packages without the need to destroy the device. This is because it employs both geometric and optical image magnifications to achieve high spatial resolution. In this paper, we propose a fully nondestructive, 3D-capable workflow for FA comprising 3D MFI and 3D XRM. We present an application of this novel workflow to 3D defect localization in a complex 2.5D device combining high bandwidth memory (HBM) devices and an application specific integrated circuit (ASIC) unit on a Si interposer with a signal pin electrical short failure.

Controlling stiffness in nanostructured hydrogels produced by enzymatic dephosphorylation

2009 ◽  
Vol 37 (4) ◽  
pp. 660-664 ◽  
Author(s):  
Kate Thornton ◽  
Andrew M. Smith ◽  
Catherine L.R. Merry ◽  
Rein V. Ulijn
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Gelation Time ◽  
Three Dimensional ◽  
Precursor Solution ◽  
Cost Effective ◽  
Cd Spectroscopy ◽  
Phosphate Ester ◽  
Self Assembling ◽  
Oscillatory Rheology

In the present paper, we report on enzyme-initiated self-assembly of Fmoc (fluoren-9-ylmethoxycarbonyl)–tyrosine hydrogels by enzymatic dephosphorylation under physiological conditions and provide evidence for the ability to control the modulus. Upon enzyme action, a self-assembling network of interconnecting fibres is formed, observed by cryo-SEM (scanning electron microscopy) and TEM (transmission electron microscopy). The concentration of alkaline phosphatase added to the Fmoc–tyrosine phosphate ester precursor solution had a direct effect on the gelation time, mechanical properties and molecular arrangements as determined through oscillatory rheology, fluorescence spectroscopy and CD spectroscopy. This highly tuneable cost-effective gel system may have applications in three-dimensional cell culture.

scholarly journals Diamond-Like Carbon Films with Low Internal Stress by a Simple Bilayer Approach

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 696 ◽  
Author(s):  
Koumei Baba ◽  
Ruriko Hatada ◽  
Stefan Flege ◽  
Wolfgang Ensinger
Keyword(s):  
Internal Stress ◽  
Three Dimensional ◽  
Single Layer ◽  
High Hardness ◽  
Cost Effective ◽  
Plasma Source ◽  
Deposition Process ◽  
Carbon Films ◽  
Bilayer Film ◽  
Plasma Source Ion Implantation

Amorphous carbon films with a high hardness usually suffer from high internal stress. To deposit films with a hard top surface but reduced internal stress, a simple bilayer approach was used. Films were prepared by plasma source ion implantation, using only hydrocarbon precursors. The single layer with the highest hardness (deposited by a low direct current (DC) voltage and radio frequency (RF) generation of the plasma) has the highest internal stress with more than 3.5 GPa. By adding an interlayer with a lower hardness, the resulting stress of the bilayer film can be reduced to below 1.4 GPa while maintaining the high hardness of the top layer. By avoiding metallic interlayers or dopants within the films, the deposition process can be kept simple and cost-effective, and it is also suitable for three-dimensional samples.

Directed Self-Assembly based Interconnect Technology for Next-Generation 2D/3D LSI

Impact ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 6-8
Author(s):  
Takafumi Fukushima
Keyword(s):  
Integrated Circuits ◽  
Systems Engineering ◽  
Self Assembly ◽  
Semiconductor Industry ◽  
Three Dimensional ◽  
Directed Assembly ◽  
Associate Professor ◽  
Active Device ◽  
Metal Compounds ◽  
3D Ics

Three-dimensional integrated circuits (3D ICs) contain multiple layers of active device chiplets and have the potential to improve signal transfer and the overall performance of a microelectronic systems, while saving energy. Dr Takafumi Fukushima is an Associate Professor based in the Department of Mechanical Systems Engineering, Tohoku University, Japan, whose research revolves around 3D/heterogeneous/flexibel integration technologies. Within the Department Fukushima focuses on self-assembly technologies. 'Self-assembly is the process by which an organised structure spontaneously forms from individual components, as a result of specific, local interactions among the components,' he explains. One of these is advanced DSA. This process enables ultrafine-pitch interconnect formation through the simple coating and heating of nanocomposites with block co-polymers and metal compounds/nanoparticles. 'DSA is a type of directed assembly which utilises the nano-phase separation of block co-polymers to create ultrafine lines, space and hole patterns, facilitating more accurate control of the feature shapes,' Fukushima outlines. 'Conventional DSA with the block co-polymers is an alternative way to photo-patterning with photoresists that are spin-on photosensitive materials to photolithographically form fine patterns and traditionally used in semiconductor industry.' Through his advanced DSA Fukushima is able to make both ultrafine patterns as well as form lateral and vertical interconnections with nanocomposites based on non-photolithographic methodology.

scholarly journals Thermomechanical modeling of IN718 alloy directed energy deposition process

2019 ◽  
Vol 304 ◽  
pp. 01023
Author(s):  
Adrien Doux ◽  
Vincent Philippe
Keyword(s):  
Energy Deposition ◽  
Turbine Blades ◽  
Cost Effective ◽  
Deposition Process ◽  
Heat Transfer Analysis ◽  
Design Stage ◽  
Experimental Heat ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Am Processes

Directed Energy Deposition (DED) Additive Manufacturing (AM) processes have a great potential to be used as cost-effective and efficient repairing and re-manufacturing processes for aerospace components such as turbine blades and landing gears. The AMOS project intends to connect repair and re-manufacturing strategies with design through accurate DED process simulation and novel multi-disciplinary design optimisation (MDO) methods. The ultimate goal is to reduce aerospace component weaknesses at design stage and prolong their lifecycles. DED AM processes are multi-physical phenomena involving high laser power melting powder or wire on a substrate. An experimental heat source has been calibrated using a heat transfer analysis of IN718 laser and powder AM on a sample part. Residual stresses and final distortion are also computed using thermal field and the evolving part distortion at each increment. Multiple hypotheses have been considered model the molten pool creation on the Heat Affected Zone (HAZ).

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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