Live Virtual Workshop on WIRE BONDING
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This virtual workshop will be hosted via MS Teams.
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The International Microelectronics Assembly and Packaging Society (IMAPS) will host a Virtual Workshop on WIRE BONDING on May 5, 2021, using the Microsoft Teams Live Event software. The objective of the Wire Bonding Virtual Workshop is to have a unique forum that brings together scientists, engineers, manufacturing and academia people from around the world who have been working in the area of Wire Bonding. This workshop has been specifically organized to allow for the presentation and debate of some of the latest technologies related to the use of Wire Bonding in semiconductor and microelectronic packaging.
10:30AM - 10:45AM
Gerneral Co-Chairs: Mike McKeown, Hesse Mechatronics, Inc.; William Crockett, Tanaka Precious Metals
10:45AM - 11:10AM
A brief historical and forecast perspective of Wirebond Market Adoption including overall IC package trends. The paper will include and discuss some of the key areas of growth and technology change for wirebonding including memory, SiP and power devices
Brandon Prior is a Senior Consultant at Prismark Partners. He joined Prismark in 1996 and is the author of their Semiconductor and Packaging Report. Brandon is responsible for the development of Prismark‘s business practice as it relates to semiconductor packaging technologies, as well as the oversight of research projects within that domain. Over the past twenty-five years, Prismark has developed business and service relationships with many of the leading electronics, semiconductor, packaging, assembly, equipment and material companies. Brandon has BA and BE degrees from Dartmouth College and the Thayer School of Engineering.
11:10AM - 11:35AM
In semiconductor packaging sector, wire bonding technique is an evergreen field. Recent days, development in wire bonding focuses on coated metal wire for memory application (stacked devices) that reveals encouraging performances. In addition, to stacked device application the wire is examined for other conventional applications. Initially, the newly developed wire  satisfies following features; high ball shear (example >23g for 54 to 58m bonded ball size). Intermetallic coverage at the bond interface is about 70 to 95% area fraction distributed in the center and periphery of the bonded ball on pre-thermal treatment. Where, the pre-thermal treatment is carried out at 175C for 2 hours, expected to fairly represents time zero bond state without excessive growth of intermetallics.
Heraeus Materials Singapore Pte Ltd
Heraeus Materials Singapore Pte Ltd
Dr. Murali received his PhD in Metallurgical Engineering from Indian Institute of Science in 1994. He has published and presented more than 100 papers in International Journals and Conferences. Murali have more than 30 invention disclosures and patent applications. Murali is currently a Senior Principal Research Engineer at Heraeus Materials, Singapore with 15 years of experience in solders/sinters/bonding wire fields and 30 years of research experience in industry and academia.
Lo Miew Wan received her bachelor‘s degree in metallurgical engineering from the University of Malaysia, Perlis in 2010. She has 8 years of research experience in bonding wire, sinter, solder, materials characterization and EBSD analysis. Miew Wan has published/presented papers in conferences and patent applications on wire bonding.
11:35AM - 12:00PM
Every new development in device performance and packaging design, can drastically affect the reliability of devices due to implementation of new materials and design changes. High performance and high reliability demands in power electronics over several decades and a short time to market development, raise the need for very fast reliability testing methods. The development of an accelerated mechanical fatigue testing method (BAMFIT) for evaluating the interfacial fatigue resistance of wire bonded interconnects is presented. This fatigue tester is designed to mimic the thermo-mechanical shear stresses by mechanical means, by applying a small ultrasonic oscillation to the bond wire and fixing the substrate to a static stage, which induces shear stresses in the interface leading to a bond wire lift-off . This was realized by implementing a resonance gripping tweezer into a commercial bonding system (BONDTEC 56xx) operating at 60 kHz. The major advantage of this method is to obtain fatigue lifetime results similar to PC test, which may contradict static shear and pull tests, in a few minutes with little to no sample preparation. The method can for example be used for optimizing bond parameters, compare bonding equipment, pretesting new material and design configurations before conducting time consuming PC tests. A selection of investigations on heavy Al and Cu wedge bonds [2,3] as well as 50m Cu ballbonds  in power electronics will be presented and compared to other testing methods using finite element analysis. The presented results suggest that this BAMFIT test can be used as an additional fast method for qualification of interconnects and assessment of the influence of wire material, bond parameter and aging.
Bernhard Czerny is a senior scientist at the TU Wien with over 10 years of experience in material science and reliability. He studied physics at the University of Vienna and specialized during his master and PhD thesis in fatigue of interconnects of micro- and powerelectronics components. He is now working in close cooperation with industrial and academic partners in several research projects, developing accelerated fatigue testing methods and material science and reliability investigations of interconnects. He has published more than 30 scientific papers, has 3 patents in the field of microelectronic reliability. His research regarding the accelerated mechanical fatigue interconnection test (BAMFIT) won the productronica Innovation Award 2019 (future market clusters) for BONDTEC.
12:00PM - 12:25PM
Wire bond has been an essential part of the packaging world for decades, and as we progress further into the 20s, its relevancy and impact is more important than ever. Interconnectivity through wire bonding is increasingly in the spotlight, with the industry constantly looking for ways to achieve optimum performance and functionality, whether packaging a single chip or multiple chips in a heterogeneous integration format with wire bond playing a critical role. During this keynote, Mark Gerber will reveal the genius of wire bond technology through exploring its evolution to present day and giving consideration to the creativity and innovation that keeps the industry wanting more and more from a workhorse technology that keeps getting better and better.
Mark is Sr. Director of Engineering and Technical Marketing at ASE (US) Inc. Mark has 25 years of semiconductor packaging experience working for ASE US Inc- Advanced Semiconductor Engineering, Texas Instruments, Motorola and Maxim Integrated in various areas of design, manufacturing and assembly with an emphasis on the development of new technologies and processes. Mark has served on multiple committees for IEEE and IMAPS is an IMAPS Fellow. He holds a bachelor‘s degree in Mechanical Engineering from Texas A&M University, has written +20 papers and publications and holds 36 semiconductor packaging related patents.
12:35PM - 1:00PM
More than 50 years ago when the wire pull test method was initially added to Mil-Std 883, in Method 2011, Condition D, the test procedure and minimum pull force values were based on pull testing of mostly ultrasonic wedge bonded aluminum and gold wires of just a few different diameters. The minimum pull force values from that original data were extrapolated to cover a much wider range of wire diameters for both gold and aluminum wires. Since the release of this test method the industry has added copper ultrasonic wedge bonds, widely adopted copper thermosonic ball bonding roughly 15 years ago, and even developed a niche market for silver thermosonic ball bonding. The industry also developed specialty bonds such as security bonds, reverse bonds also called "stitch on ball", and even multiloop wires and ribbons. In all that time neither the test procedure nor the minimum pull force values in Method 2011 were reviewed to determine their appropriateness for these new materials or new types of bonds, even though the industry widely referenced the test method for all of them and thus, by default, accepted its use for all of them.
To address these issues, JEDEC's JC14.1 Test Methods committee agreed to work jointly with JC13 to create a new, wire pull test method document under JC14.1 that would be a companion to the JESD22-B116 Ball Bond Shear Test Method that had been recently revised to address the shearing of Cu ball bonds. This new document will use Method 2011, Condition D as its basis, but expand on its scope to cover copper wire bonds, both ultrasonic wedge and thermosonic ball bonds. The new test method will describe the process for a ball pull test and a stitch pull test that are referenced for copper bonds by AEC Q006. The test method will also provide guidance on how to perform pull testing on some of the different bond types used today such as reverse bonds, multiloop bonds, stacked die, and several others. The working group would also work to propose minimum pull values for copper wire bonds which JC14 would reference in JESD47. After the joint working group completes its work, which is targeted for some time in 2022, JC13 would then be able to use the output of this working group to update Method 2011 Condition D
This presentation will first briefly talk about the updates made to B116 to cover Cu wire bonds, but mainly focus on the work that has so far been completed by the joint working group for the proposed JESD22-B120, Wire Bond Pull Test Methods.
Curtis is a Senior Engineer for IBM in its System Supply Chain (SSC) Engineering organization. He has 33 years of experience in IC packaging and the interaction of IC packages with electronic card assembly, with emphasis on moisture sensitivity and process/temperature sensitivity issues. Within the SSC he is the SME for environmental (RoHS, REACH, etc.) and Pb-free issues for electronic components. He has been active in JEDEC JC14.1, "Test Methods" and JC14.3, "Qualifications Standards" committees for nearly 20 years and for the past 15 years has been chairman of the JEDEC JC14.4, "Quality Processes and Methods" committee. He has actively participated in industry standards generation for 32 years, initially with the release of IPC-786 (Moisture Sensitivity) through its current form today as J-STD-020. Curtis graduated from the University of Wisconsin - Madison with a BS and MS in Engineering Mechanics.
1:00PM - 1:25PM
Semiconductor devices are subject to increasingly higher quality and reliability standards. Thus, manufacturers of these devices must take extensive measures to ensure these standards are met while new highly integrated, complex packaging solutions including a variety of new bond wire materials are being adopted. Consequently, bonding wires inside semiconductor packages must often be exposed by decapsulation to enable further reliability testing or failure analysis. Conventional decapsulation technologies (acid and CF4-based plasma) are sufficient when dealing with Au wires, but reach their limits when dealing with other bond wire materials due to the introduction of artifacts. As the Cu and PCC wire trend is at a historical high for demand, it is essential that an alternative artifact-free decapsulation method is used. To overcome the limitations of conventional decapsulation techniques and enable artifact-free sample preparation, a fully automatic decapsulation machine has been developed based on atmospheric pressure Microwave Induced Plasma (MIP). This novel technology is based on oxygen-only and patent-pending hydrogen etching chemistry. The highly confined plasma beam of the MIP machine results in a high flux of neutral radicals in the plasma afterglow, which contributes to the high etching rate of molding compound and high etching selectivity for all common wirebond materials, such as gold, aluminum, silver, PCC and copper. Gentle MIP etching exposes challenging elements such as Cu and Ag metallization and bond wires, without causing corrosion, unlike acid. As opposed to typical plasma decapsulation which is highly uncontrollable and leads to over-etching of the passivation and die, MIP decapsulation preserves electrical functionality of investigated devices and allows efficient harvesting of evidence for true root cause analysis.
Violeta Prodanovic received her M.Sc. in electrical engineering from University of Belgrade in 2013. In 2019 she obtained her Ph.D degree in The Electronic Components, Technology and Materials (ECTM) group, Delft University of Technology, after conducting research on ultra-thin transmission dynodes for a novel type of a timed photon counter. She has joined JIACO Instruments in 2020 as a sales engineer.
1:25PM - 1:50PM
Wide-bandgap (WBG) semiconductor devices are key enablers in the evolution of power electronic technologies, specifically for their capability to jointly deliver an enhanced efficiency, power density, and reliability of electrical energy conversion system. Especially, Silicon Carbide (SiC) devices exhibit much lower switching losses, higher breakdown voltages, faster switching speed, and higher allowable operating temperatures than their Si counterparts. These benefits drive down the overall size of power systems allowing more compact designs to be constructed, and eventually would enable substantially reduction of the cost of energy (COE) of electrical energy conversion system. However, these benefits come at the cost of significant challenges for semiconductor packaging. More specifically, the fast-switching transients lead to issues with package-internal electromagnetic parasitics. Among them are voltage over-shoots, ringing, asynchronous switching of parallel devices and differential and common mode emissions. Moreover, due to the increased operating temperature, improvement of reliability capability is also a key aspect for SiC power modules. Therefore, wire bonding technology, as the most commonly used chip top-side connection method, has received widespread attention in order to realize low parasitics and high reliability packaging architectures for SiC power modules. Innovations at this level involve different solutions such as multi-stitch wire bonding technology, ribbon bonding technology and copper wire bonding technology. The objective of this presentation is to combine these key innovations into the different proposed low-parasitics and high reliability package architecture to push the boundaries of high-speed and high-power SiC power modules.
University of Arkansas
University of Arkansas
Yuxiang Chen received the B.Sc and M.Sc degrees from the Department of Information and Electrical Engineering, China University of Mining and Technology, Xuzhou, China, in 2011 and 2014, respectively, and the Ph.D degree in the College of Electrical Engineering, Zhejiang University, Hangzhou, China in 2019. She is currently working as a Postdoc at the Department of Electrical Engineering in University of Arkansas, Fayetteville, US. Her research interests include high power module package design and fabrication.
Alan Mantooth received the B.S.E.E. and M.S.E.E. degrees from the University of Arkansas in 1985 and 1986, and the Ph.D. degree from Georgia Tech in 1990. He then joined Analogy, a startup company in Oregon. In 1998, he joined the faculty of the Department of Electrical Engineering at the University of Arkansas, Fayetteville, where he currently holds the rank of Distinguished Professor. His research interests now include analog and mixed-signal IC design & CAD, semiconductor device modeling, power electronics, power electronic packaging, and cybersecurity. Dr. Mantooth helped establish the National Center for Reliable Electric Power Transmission (NCREPT) at the UA in 2005. Professor Mantooth serves as the Executive Director both the NSF Industry/University Cooperative Research Center on GRid-connected Advanced Power Electronic Systems (GRAPES) and the Cybersecurity Center on Secure, Evolvable Energy Delivery Systems (SEEDS) funded by the U.S. Department of Energy. Dr. Mantooth holds the 21st Century Research Leadership Chair in Engineering. He currently serves as Senior Past-President for the IEEE Power Electronics Society and Editor-in-Chief of the IEEE Open Journal of Power Electronics. Dr. Mantooth is a Fellow of IEEE, a member of Tau Beta Pi and Eta Kappa Nu, and registered professional engineer in Arkansas.
2:00PM - 2:25PM
The top level or governing military spec for hybrids and microwave modules is Mil-Prf-38534, and for monolithic ICs it’s Mil-Prf-38535. These performance specs have numerous call outs for testing of wirebonds per Mil-Std-883 with regard to qualification, in-process controls and 100% screen testing. This presentation will highlight these wirebond tests methods and show where and how they are employed to assure reliable products for the US military, and further discuss how this quality system compares to a modern day high volume commercial wirebonding process. The talk will also focus on recent updates to the mil spec visual wirebond inspection criteria and highlight some work that’s being done in the DoD/JEDEC to develop test methods to accommodate copper wirebonding.
TJ Green Associates LLC
Thomas J. Green has more than 38 years combined experience in industry/academia and the DoD. He earned a B.S from Lehigh University in Materials Engineering and an MEA from Univ of Utah. He is a recognized expert in materials and processes used to assemble hybrids, RF microwave modules/5G, Class III medical implants, optoelectronics, and other types of hermetic/non-hermetic packaged microcircuits. Serving as a Research Scientist at the USAF RADC, Tom worked as a reliability engineer analyzing component failures and in industry he was the hybrid process engineer at Lockheed Denver. He has invaluable experience in wirebond, die attach, hermetic sealing, FA and root cause identification, For the last 18 years, Tom’s expertise has helped position TJ Green Associates LLC as a recognized industry leader in teaching and consulting services for high-reliability military, space, and medical device applications. Tom is a retired military officer and a Fellow of IMAPS (International Microelectronics and Packaging Society).
2:25PM - 2:50PM
Wide-band gap (WBG) semiconductors, such as SiC and GaN, have accelerated the ability to shrink the volumetric size and weight of power conversion systems by optimizing at the module level, due to their inherent high frequency, high temperature and high voltage capabilities. Power electronic module components, specifically flexible welded interconnects, behave like transmission lines at higher frequencies. Therefore, interconnects contribute to the power losses within the power module, and ultimately affect overall efficiency. Voltage and current overshoots and insertion/return losses and phenomena such as proximity and skin effect will also have noticeable effect on the performance of the module as device switching is pushed into mid to high MHz range. Thus, to aid in design and development of advanced power modules this presentation with the help of FEA multiphysics solvers will firstly study the current carrying capacity and fusing time of different diameter Al heavy wire bonds interconnects. Then for a rated current, the multiple wire bond profile is considered to mitigate the negative effects from the fastest rising/fall edge of voltage and current switching high frequency components. The presentation will also compare stack wirebonds against parallel wire using Ansys Q3D Extractor in order to extract the physical parasitic impedances. Characteristic impedance is then calculated using parasitic resistance, inductance, capacitance and conductance for each structure. Next, reflection coefficients, voltage standing wave ratios (VSWR) and return losses are calculated in order to observe improvement in interconnect losses. The ultimate goal of the presentation is to further the establishment of an evolution in thinking and designing when it comes to the WBG power electronic packaging practices and culture.
North Carolina State University
Utkarsh Mehrotra received his BTech in Electrical Engineering from Manipal Institute of Technology and is pursuing his doctorate in electrical engineering through the NSF FREEDM Systems Center in the Electrical and Computer Engineering Department at North Carolina State University. His primary research is within Power America and the Packaging Research in Electronic Energy Systems (PREES) Laboratory. Research interests includes the design, simulation, fabrication, and testing of power electronics packaging topologies that harness the capabilities of wide-bandgap (WBG) semiconductor technology (GaN and SiC), with a focus on solid state circuit protection and their controls, power converters and high voltage high density power modules scalable to 25kV voltage range. He has also held an internship at the Faraday Future, provided presentations and tutorials at several conferences, and has over 10 publications.
2:50PM - 3:15PM
During both ball and wedge bonding, wire is massively deformed between the bond tool and the bond pad or substrate. The dominant variables affecting deformation are ultrasonic energy, temperature, bond force and bond time. Of these, ultrasonic energy has the largest effect. It changes material properties, lowering yield stress and allowing deformation to occur at lower applied stress than otherwise required. Deformation exposes new surface material that is clean and has not been exposed to atmospheric contamination and oxidation. As the newly exposed wire and bond pad surfaces mix, they form diffusion couples that grow and transform into the intermetallic weld nugget. Initially the nugget is a simple mixture but temperature and time very quickly allow diffusion to transform the mixture into the stable compounds described by the equilibrium phase diagram. This talk will discuss the mechanisms behind the formation of ball and wedge bonds.
Process Solutions Consulting, Inc.
Lee Levine is Principal Consultant with Process Solutions Consulting, Inc. where he consults and trains on Wire Bonding, SEM with EDS for FA, and statistical analysis with DOE. He spent 20 years as Sr. Staff Metallurgist for K&S where he wrote approximately 70 technical papers and received 4 patents. He has a B.S Eng in Metallurgy and Materials Sci from Lehigh University, Bethlehem, PA. IMAPS has awarded him the Daniel Hughes and the John Wagnon Awards for his technical contributions.
General Co-Chairs: Mike McKeown, Hesse Mechatronics, Inc.; William Crockett, Tanaka Precious Metals