Download or read book Study of Mechanism of Ultrasonic Wire Bonding Process written by Dong Zhang and published by . This book was released on 2003 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Ultrasound in Microelectronic Ultrasonic Wire Bonding written by Ivan Lum and published by . This book was released on 2007 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrasonic wire bonding is the most utilized technique in forming electrical interconnections in microelectronics. However, there is a lacking in the fundamental understanding of the process. In order for there to be improvements in the process a better understanding of the process is required. The mechanism of the bond formation in ultrasonic wire bonding is not known. Although there have been theories proposed, inconsistencies have been shown to exist in them. One of the main inconsistencies is the contribution of ultrasound to the bonding process. A series of experiments to investigate the mechanism of bond formation are performed on a semi automatic wire bonder at room temperature. 25 [mu]m diameter Au wire is ball bonded and also 25 [mu]m diameter Al wire is wedge-wedge bonded onto polished Cu sheets of thickness 2 mm. It is found that a modified microslip theory can describe the evolution of bonding. With increasing ultrasonic power the bond contact transitions from microslip into gross sliding. The reciprocating tangential relative motion at the bond interface results in wear of surface contaminants which leads to clean metal/metal contact and bonding. The effect of superimposed ultrasound during deformation on the residual hardness of a bonded ball is systematically studied for the first time. An innovative bonding procedure with in-situ ball deformation and hardness measurement is developed using an ESEC WB3100 automatic ball bonder. 50 [mu]m diameter Au wire is bonded at various ultrasound levels onto Au metallized PCB substrate at room temperature. It is found that sufficient ultrasound which is applied during the deformation leads to a bonded ball which is softer than a ball with a similar amount of deformation without ultrasound. No hardening of the 100 [mu]m diameter Au ball is observed even with the maximum ultrasonic power capable of the equipment of 900 mW. In summary, the fundamental effect of ultrasound in the wire bonding process is the reciprocating tangential displacement at the bond interface resulting in contaminant dispersal and bonding. A second effect of ultrasound is the softening of the bonded material when compared to a similarly non-ultrasound deformed ball.
Download or read book A Thermomechanical Analysis of an Ultrasonic Bonding Mechanism written by Chunbo Zhang and published by . This book was released on 2011 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: A systematic experimental and numerical combined study of the thermomechanical bonding mechanisms in the ultrasonic welding (UW) process was conducted. A fully coupled thermomechanical finite element model has been built to fully understand the evolution and coupling between the in-process thermomechanical variables. The severe, localized, plastic deformation at the bond region is believed to be the major phenomenon for bond formation in ultrasonic welding. The influences of substrate dimensions on bond formation were studied and explained with an analytical vibration model. The formation of banded and cyclic stress-strain maxima in the substrate was found to be caused by superposition of vibrations. A push-pin type, combined experimental and numerical, method has been developed, validated, and applied to quantitatively determine the bond strength of UW parts. The best bond strength produced using the set of process parameters in this study was 75% of the ultimate tensile strength of the base material (Al3003-H18). Effects of UW parameters (normal pressure, vibration amplitude, and travel velocity) on bond strength have been characterized. Due to the weak vertical bond strength of UW parts, the pressurized post-weld heat treatment (PWHT) approach is originally proposed to improve the bond strength. The results show that the modified bond strength, up to 96% of the strength of the base material, can be achieved under the optimum parameters of 2.5 MPa pressure, 450 C temperature, and 1.5 h time.
Download or read book Copper Wire Bonding written by Preeti S Chauhan and published by Springer Science & Business Media. This book was released on 2013-09-20 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks. Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material. However, copper wire bonding has several process and reliability concerns due to its material properties. Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation. In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed. The book also discusses best practices and recommendations on the bond process, bond–pad metallurgies, and appropriate reliability tests for copper wire-bonded electronic components. In summary, this book: Introduces copper wire bonding technologies Presents copper wire bonding processes Discusses copper wire bonding metallurgies Covers recent advancements in copper wire bonding including the bonding process, equipment changes, bond–pad materials and surface finishes Covers the reliability tests and concerns Covers the current implementation of copper wire bonding in the electronics industry Features 120 figures and tables Copper Wire Bonding is an essential reference for industry professionals seeking detailed information on all facets of copper wire bonding technology.
Download or read book Journal of Research of the National Bureau of Standards written by United States. National Bureau of Standards and published by . This book was released on 1977 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ire Bonding in Microelectronics written by George G. Harman and published by McGraw Hill Professional. This book was released on 1997 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first edition of this work is considered a classic reference in the field. This new edition updates the entire work and adds 100 pages of information covering new materials and techniques such as fine pitch
Download or read book NBS Special Publication written by and published by . This book was released on 1975 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quality Control of the Ultrasonic Wire Bonding Process written by R. Rodwell and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanical and Tribological Aspects of Microelectronic Wire Bonding written by Aashish Satish Shah and published by . This book was released on 2010 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis is on improving the understanding of mechanical and tribological mechanisms in microelectronic wire bonding. In particular, it focusses on the development and application of quantitative models of ultrasonic (US) friction and interfacial wear in wire bonding. Another objective of the thesis is to develop a low-stress Cu ball bonding process that minimizes damage to the microchip. These are accomplished through experimental measurements of in situ US tangential force by piezoresistive microsensors integrated next to the bonding zone using standard complementary metal oxide semiconductor (CMOS) technology. The processes investigated are thermosonic (TS) Au ball bonding on Al pads (Au-Al process), TS Cu ball bonding on Al pads (Cu-Al process), and US Al wedge-wedge bonding on Al pads (Al-Al process). TS ball bonding processes are optimized with one Au and two Cu wire types, obtaining average shear strength (SS) of more than 120 MPa. Ball bonds made with Cu wire show at least 15% higher SS than those made with Au wire. However, 30% higher US force induced to the bonding pad is measured for the Cu process using the microsensor, which increases the risk of underpad damage. The US force can be reduced by: (i) using a Cu wire type that produces softer deformed ball results in a measured US force reduction of 5%; and (ii) reducing the US level to 0.9 times the conventionally optimized level, the US force can be reduced by 9%. It is shown that using a softer Cu deformed ball and a reduced US level reduces the extra stress observed with Cu wire compared to Au wire by 42%. To study the combined effect of bond force (BF) and US in Cu ball bonding, the US parameter is optimized for eight levels of BF. For ball bonds made with conventionally optimized BF and US settings, the SS is [dsim] 140 MPa. The amount of Al pad splash extruding out of bonded ball interface (for conventionally optimized BF and US settings) is between 10-12 [mu]m. It can be reduced to 3-7 [mu]m if accepting a SS reduction to 50-70 MPa. For excessive US settings, elliptical shaped Cu bonded balls are observed, with the major axis perpendicular to the US direction. By using a lower value of BF combined with a reduced US level, the US force can be reduced by 30% while achieving an average SS of at least 120 MPa. These process settings also aid in reducing the amount of splash by 4.3 [mu]m. The US force measurement is like a signature of the bond as it allows for detailed insight into the tribological mechanisms during the bonding process. The relative amount of the third harmonic of US force in the Cu-Al process is found to be five times smaller than in the Au-Al process. In contrast, in the Al-Al process, a large second harmonic content is observed, describing a non-symmetric deviation of the force signal waveform from the sinusoidal shape. This deviation might be due to the reduced geometrical symmetry of the wedge tool. The analysis of harmonics of the US force indicates that although slightly different from each other, stick-slip friction is an important mechanism in all these wire bonding variants. A friction power theory is used to derive the US friction power during Au-Al, Cu-Al, and Al-Al processes. Auxiliary measurements include the current delivered to the US transducer, the vibration amplitude of the bonding tool tip in free-air, and the US tangential force acting on the bonding pad. For bonds made with typical process parameters, several characteristic values used in the friction power model such as the ultrasonic compliance of the bonding system and the profile of the relative interfacial sliding amplitude are determined. The maximum interfacial friction power during Al-Al process is at least 11.5 mW (3.9 W/mm2), which is only about 4.8% of the total electrical power delivered to the US transducer. The total sliding friction energy delivered to the Al-Al wedge bond is 60.4 mJ (20.4 J/mm2). For the Au-Al and Cu-Al processes, the US friction power is derived with an improved, more accurate method to derive the US compliance. The method uses a multi-step bonding process. In the first two steps, the US current is set to levels that are low enough to prevent sliding. Sliding and bonding take place during the third step, when the current is ramped up to the optimum value. The US compliance values are derived from the first two steps. The average maximum interfacial friction power is 10.3 mW (10.8 W/mm2) and 16.9 mW (18.7 W/mm2) for the Au-Al and Cu-Al processes, respectively. The total sliding friction energy delivered to the bond is 48.5 mJ (50.3 J/mm2) and 49.4 mJ (54.8 J/mm2) for the Au-Al and Cu-Al processes, respectively. Finally, the sliding wear theory is used to derive the amount of interfacial wear during Au-Al and Cu-Al processes. The method uses the US force and the derived interfacial sliding amplitude as the main inputs. The estimated total average depth of interfacial wear in Au-Al and Cu-Al processes is 416 nm and 895 nm, respectively. However, the error of estimation of wear in both the Au-Al and the Cu-Al processes is [dsim] 50%, making this method less accurate than the friction power and energy results. Given the error in the determination of compliance in the Al-Al process, the error in the estimation of wear in the Al-Al process might have been even larger; hence the wear results pertaining to the Al-Al process are not discussed in this study.
Download or read book Investigations on the Mechanisms of Ultrasonic Wire Bonding written by Yangyang Long and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microjoining and Nanojoining written by Y N Zhou and published by Elsevier. This book was released on 2008-03-27 with total page 835 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many important advances in technology have been associated with nanotechnology and the miniaturization of components, devices and systems. Microjoining has been closely associated with the evolution of microelectronic packaging, but actually covers a much broader area, and is essential for manufacturing many electronic, precision and medical products.Part one reviews the basics of microjoining, including solid-state bonding and fusion microwelding. Part two covers microjoining and nanojoining processes, such as bonding mechanisms and metallurgy, process development and optimization, thermal stresses and distortion, positioning and fixturing, sensing, and numerical modelling. Part three discusses microjoining of materials such as plastics, ceramics, metals and advanced materials such as shape memory alloys and nanomaterials. The book also discusses applications of microjoining such as joining superconductors, the manufacture of medical devices and the sealing of solid oxide fuel cells.This book provides a comprehensive overview of the fundamental aspects of microjoining processes and techniques. It is a valuable reference for production engineers, designers and researchers using or studying microjoining technologies in such industries as microelectronics and biomedical engineering. Reviews the basics of nanojoining including solid-state bonding and fusion microwelding Covers microjoining and nanojoining processes such as bonding mechanisms and metallurgy, sensing and numerical modelling Examines applications of microjoining such as the manufacturing of medical devices, and the sealing of solid oxide fuel cells
Download or read book NBS Technical Note written by and published by . This book was released on 1972-06 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Power Ultrasonics written by Juan A. Gallego-Juarez and published by Woodhead Publishing. This book was released on 2023-04-06 with total page 948 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power Ultrasonics: Applications of High-Intensity Ultrasound, Second Edition provides a comprehensive reference on the fundamentals, processing, engineering, medical, food and pharmaceutical applications of ultrasonic processing. Chapters cover the fundamentals of nonlinear propagation of ultrasonic waves in fluids and solids, discuss the materials and designs of power ultrasonic transducers and devices, identify applications of high power ultrasound in materials engineering and mechanical engineering, food processing technology, environmental monitoring and remediation and industrial and chemical processing (including pharmaceuticals), medicine and biotechnology, and cover developments in ultrasound therapy and surgery applications.The new edition also includes recent advances in modeling, characterization and measurement techniques, along with additive manufacturing and micromanufacturing. This is an invaluable reference for graduate students and researchers working in the disciplines of materials science and engineering. In addition, those working on the physics of acoustics, sound and ultrasound, sonochemistry, acoustic engineering and industrial process technology, R&D managers, production, and biomedical engineers will find it useful to their work. Covers the fundamentals of nonlinear propagation of ultrasonic waves in fluids and solids Discusses the materials and designs of power ultrasonic transducers and devices Considers state-of-the-art power sonic applications across a wide range of industries
Download or read book Fundamental Studies on the Mechanism of Ultrasonic Welding written by W. J. Lewis and published by . This book was released on 1961 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fundamental mechanisms of ultrasonic welding and the application of this process to the joining of various heat-resistant materials were investigated. Previous studies which had shown the effects of time, temperature, and clamping force on ultrasonic welds were expanded to include studies of the shear force during welding. Ultrasonic spot welds made in various combinations of heat-resistant alloys generally confirmed the results of previous work with these alloys. Cracks were found at the edges of the spot welds in most of the material combinations studied. The effects of these cracks on weldment properties varied with the material. The presence of a reaction zone, apparently consisting of intermetallic compounds, was apparent in ultrasonic welds made between Ti and stainless steel. These findings indicate that ultrasonic welding is not suitable for the production of aircraft-quality spot welds in heat- resistant and dissimilar metal combinations. It is apparent as a material's hardness increases, and the ratio of tensile strength to yield strength decreases, that weldability by the ultrasonic process decreases.
Download or read book Modern Manufacturing Engineering written by J. Paulo Davim and published by Springer. This book was released on 2015-06-19 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers recent research and trends in Manufacturing Engineering. The chapters emphasize different aspects of the transformation from materials to products. It provides the reader with fundamental materials treatments and the integration of processes. Concepts such as green and lean manufacturing are also covered in this book.
Download or read book Light Metals Advances in Research and Application 2012 Edition written by and published by ScholarlyEditions. This book was released on 2012-12-26 with total page 1913 pages. Available in PDF, EPUB and Kindle. Book excerpt: Light Metals—Advances in Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Light Metals. The editors have built Light Metals—Advances in Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Light Metals in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Light Metals—Advances in Research and Application: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
Download or read book The Destructive Bond Pull Test written by John Albers and published by . This book was released on 1976 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
