Alexander Coucoulas

Last updated

Alexander Coucoulas is an American inventor, research engineer, and author. He was named "father of thermosonic bonding" by George Harman, [1] the world's foremost authority on wire bonding, where he referenced Coucoulas's leading edge publications in his book, Wire Bonding In Microelectronics. [2] [3] A thermosonic bond is formed using a set of parameters which include ultrasonic, thermal and mechanical (force) energies.

Contents

Thermosonic bonding is widely used to electrically connect silicon integrated circuit microprocessor chips [4] [5] into computers as well as a myriad of other electronic devices that require wire bonding.

Wires connected to a silicon integrated circuit using thermosonic bonding Integrated circuit wire bonded.png
Wires connected to a silicon integrated circuit using thermosonic bonding

As a result of Coucoulas introducing thermosonic bonding lead wires in the early 1960s, its applications and scientific investigations by researchers throughout the world have grown as confirmed by the thousands of Google search-sites. The all-important proven reliability of thermosonic bonding, as confirmed by these investigations, has made it the process of choice for connecting these crucially important electronic components. And since relatively low bonding parameters were shown to form reliable thermosonic bonds, the integrity of the fragile silicon integrated circuit chip central processor unit or CPU, is assured throughout its intended lifetime use as the "brains" of the computer.

Personal background

Coucoulas retired from AT&T Bell Labs as a member of the technical staff in 1996 where he pioneered research in the areas of electronic/photonics packaging, laser technology and optical fibers which resulted in numerous patents, and publications. He was twice awarded best paper which he presented at the 20th and 43rd IEEE Electronic Components Conference for "Compliant Bonding" in 1970 " [6] and AlO Bonding in 1993 [7] both of which were his patented inventions. [8] [9] His Ionian-Greek immigrant parents were born in the Biblical city of Smyrna. His single-parent father, Demetrios (James) Koukoulas (as a maimed Smyrnaean Greek soldier), was rescued from the coastal waters of the Aegean sea by a Japanese naval cruiser while in view and during the devastating fire of Smyrna in September 1922. The Japanese cruiser brought him to Pereaus, Greece where he immigrated to The United States via Ellis Island on the SS King Alexander in November of that same year. [10] [11]

Coucoulas is a native New Yorker who served in the US Army as a combat engineer in the Far East Command in the early 1950s, and was awarded the National Defense Service Medal for the Korean War (1950-1954). He then obtained his undergraduate and graduate degrees in Metallurgical Engineering and Material Science at New York University which was financed by the GI Bill, a graduate scholarship and part-time jobs in the New York Metropolitan area. His graduate thesis was under the tutorage of Dr. Kurt Komarek, who is a former Rector (President) and present professor emeritus of the University Of Vienna. Coucoulas co-authored a paper with Dr. Komarek which included his thesis,. [12] His spouse, Marie Janssen Coucoulas, played a significant supportive role throughout his professional career while also contributing to the welfare of learning disabled children in the capacity of a professional Learning Consultant. His daughters, Diane and Andrea, distinguished themselves as a University of North Carolina Professor and elementary student counselor respectively.

Engineering research

Thermosonic bonding

In the mid-1960s, Coucoulas [2] [3] reported the first thermosonic wire bonds using a combination of heat, ultrasonic vibrations and pressure which led to his first invention. He first set up a commercial ultrasonic wire bonder (capable of transmitting vibratory energy and pressure) in order to investigate the attachment of aluminum wires to tantalum thin films deposited on glass substrates which simulated bonding a lead wire to the fragile metallized silicon integrated circuit "chip". He observed that the ultrasonic energy and pressures levels needed to sufficiently deform the wire and form the required contact areas significantly increased the incidents of cracks in the glass or silicon chip substrates. A means of heating the bond region was then added to the ultrasonic bonder. The bond region was then heated during the ultrasonic bonding cycle which virtually eliminated the glass failure mode since the wire dramatically deformed to form the required contact area while using significantly lower ultrasonic energy and pressure levels. The enhanced wire deformation during the ultrasonic bonding cycle was attributed to the transition from cold working (or strain hardening of the wire) to near hot working conditions where its softness was enhanced. As the bonding temperature was increased the onset of recrystallization (softening mechanism) occurs where the strain hardening is most extensive. Thus the dual mechanisms of thermal softening and ultrasonic softening which is caused by vibratory energy interacting at the atomic lattice level, [13] facilitated the desired wire deformation. Christian Hagar [14] and George Harman [4] stated that in 1970 Alexander Coucoulas [3] reported additional work in forming thermosonic-type bonds which he initially called hot work ultrasonic bonding. In this case, copper wires were bonded to palladium thin films deposited on aluminum oxide substrates. As a result of these earliest reported thermosonic wire bonds, G.Harman [4] stated "as such, Alexander Coucoulas is the Father of Thermosonic Bonding". At present,[ when? ] the majority of connections to silicon integrated circuits are made using thermosonic bonding because it employs lower bonding temperatures, forces and dwell times than thermocompression bonding, as well as lower vibratory energy levels than ultrasonic bonding, to form the required bond area. As a result of using lower bonding parameters to form the required contact area, Thermosonic Bonding largely eliminates damaging the relatively fragile silicon integrated circuit micro-chip during the bonding cycle. The proven reliability of thermosonic bonding has made it the process of choice, since such potential failure modes could be costly whether they occur during the manufacturing stage or detected later, during an operational field-failure of a micro-chip which had been permanently connected inside a computer or a myriad of other electronic devices.

Burmeister et al., of Hamburg University, Germany, reported that using solely ultrasonic power to bond gold wires to YBa2Cu3O7 microstructures, such as microbridges, Josephson junctions and superconducting interference devices (DC SQUIDS) can degrade them. The researchers further found that the problem was overcome by using Coucoulas' thermosonic bonding process where it left the microstructure device intact so they could be employed. [15]

Growing applications of thermosonic bonding

The majority of connections to the silicon integrated circuit chip are made using thermosonic bonding [16] because it employs lower bonding temperatures, forces and dwell times than thermocompression bonding, as well as lower vibratory energy levels and forces than ultrasonic bonding to form the required bond area. Therefore, the use of thermosonic bonding eliminates damaging the relatively fragile silicon integrated circuit chip during the bonding cycle. The proven reliability of thermosonic bonding has made it the process of choice, since such potential failure modes could be costly whether they occur during the manufacturing stage or detected later, during an operational field-failure of a chip which had been connected inside a computer or a myriad of other microelectronic devices.

Thermosonic bonding is also used in the flip chip process which is an alternate method of electrically connecting silicon integrated circuits.[ citation needed ]

Josephson effect and superconducting interference (DC SQUID) devices use the thermosonic bonding process as well. In this case, other bonding methods would degrade or even destroy YBaCuO7 microstructures, such as microbridges, Josephson junctions and superconducting interference devices [17] (DC SQUID).

When electrically connecting light-emitting diodes with thermosonic bonding techniques, an improved performance of the device has been shown. [18]

Compliant bonding

"Compliant bonding" was awarded best paper presentation and publication at the 1970 IEEE Electronic Components Conf. Click photo to read original file resolution. CompliantBondingPublic 1-10.pdf
"Compliant bonding" was awarded best paper presentation and publication at the 1970 IEEE Electronic Components Conf. Click photo to read original file resolution.
"Compliant Bonding" Patent. Click above to read Original File Compliantbondpat10001.pdf
"Compliant Bonding" Patent. Click above to read Original File

Following his pioneering of thermosonic bonding, Coucoulas invents "Compliant Bonding [19] which was a means of solid-state bonding the extended electroformed leads of a "beam leaded chip" to the outside world. It was a unique method of solid state bonding in that the bonding energy (heat and pressure) was transmitted through a compliant aluminum tape. The compliant tape overcame the thickness variations of the beam leads and also acted as a chip carrier to the bonding site. In 1971, he was awarded best paper-presentation for "Compliant Bonding" [6] which was among more than 90 papers presented at the 20th IEEE Electronic Components Conference in 1970 by engineers and research scientists from around the world.

Click pictures to enlarge view

AlO bonding used to form a photonic switch

AlO bonding patent Alopat4pages.pdf
AlO bonding patent

Twenty-three years after being awarded best paper for compliant bonding, Coucoulas was again awarded "outstanding paper" at the 43rd Electronic Components and Technology Conference in 1993. It was titled, "AlO Bonding: A Method of Joining Oxide Optical Components to Aluminum Coated Substrates." [20] He also was awarded a U.S. patent for inventing AlO bonding. [9]

Microstructure of solid carbon dioxide ("dry ice")

Coucoulas' first industrial research position was at air reduction central research facility in New Jersey where he investigated and coauthored a paper on in the transactions of the Metallurgical Society of AIME entitled, "Some Observations on the Microstructure and Fragmentation of Solid Carbon Dioxide" [21] with the following abstract:

Solid carbon dioxide (dry ice), which exists metastably as a constantly subliming molecular solid in a normal room temperature environment, was shown to exhibit many microstructural features which are similar to those observed in metals and ceramics at temperatures approaching their melting points. An investigation was made of factors affecting a costly brittleness condition known as "sandiness" which occurred in manufactured blocks of dry ice (polycrystalline solid carbon dioxide). The sandiness was found to be highly dependent on specific manufacturing and storage conditions that cause excessive grain growth which leads to a concentration of gas filled pores in the decreasing grain boundary regions.

Awards

Selected publications and presentations

Related Research Articles

<span class="mw-page-title-main">Integrated circuit</span> Electronic circuit formed on a small, flat piece of semiconductor material

An integrated circuit (IC), also known as a microchip, computer chip, or simply chip, is a small electronic device made up of multiple interconnected electronic components such as transistors, resistors, and capacitors. These components are etched onto a small piece of semiconductor material, usually silicon. Integrated circuits are used in a wide range of electronic devices, including computers, smartphones, and televisions, to perform various functions such as processing and storing information. They have greatly impacted the field of electronics by enabling device miniaturization and enhanced functionality.

<span class="mw-page-title-main">MEMS</span> Very small devices that incorporate moving components

MEMS is the technology of microscopic devices incorporating both electronic and moving parts. MEMS are made up of components between 1 and 100 micrometres in size, and MEMS devices generally range in size from 20 micrometres to a millimetre, although components arranged in arrays can be more than 1000 mm2. They usually consist of a central unit that processes data and several components that interact with the surroundings.

<span class="mw-page-title-main">Very-large-scale integration</span> Creating an integrated circuit by combining many transistors into a single chip

Very-large-scale integration (VLSI) is the process of creating an integrated circuit (IC) by combining millions or billions of MOS transistors onto a single chip. VLSI began in the 1970s when MOS integrated circuit chips were developed and then widely adopted, enabling complex semiconductor and telecommunication technologies. The microprocessor and memory chips are VLSI devices.

<span class="mw-page-title-main">Wire bonding</span> Technique used to connect a microchip to its package

Wire bonding is a method of making interconnections between an integrated circuit (IC) or other semiconductor device and its packaging during semiconductor device fabrication. Wire bonding can also be used to connect an IC to other electronics or to connect from one printed circuit board (PCB) to another, although these are less common. Wire bonding is generally considered the most cost-effective and flexible interconnect technology and is used to assemble the vast majority of semiconductor packages. Wire bonding can be used at frequencies above 100 GHz.

<span class="mw-page-title-main">Flip chip</span> Technique that flips a microchip upside down to connect it

Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to external circuitry with solder bumps that have been deposited onto the chip pads. The technique was developed by General Electric's Light Military Electronics Department, Utica, New York. The solder bumps are deposited on the chip pads on the top side of the wafer during the final wafer processing step. In order to mount the chip to external circuitry, it is flipped over so that its top side faces down, and aligned so that its pads align with matching pads on the external circuit, and then the solder is reflowed to complete the interconnect. This is in contrast to wire bonding, in which the chip is mounted upright and fine wires are welded onto the chip pads and lead frame contacts to interconnect the chip pads to external circuitry.

In semiconductor manufacturing, silicon on insulator (SOI) technology is fabrication of silicon semiconductor devices in a layered silicon–insulator–silicon substrate, to reduce parasitic capacitance within the device, thereby improving performance. SOI-based devices differ from conventional silicon-built devices in that the silicon junction is above an electrical insulator, typically silicon dioxide or sapphire. The choice of insulator depends largely on intended application, with sapphire being used for high-performance radio frequency (RF) and radiation-sensitive applications, and silicon dioxide for diminished short-channel effects in other microelectronics devices. The insulating layer and topmost silicon layer also vary widely with application.

<span class="mw-page-title-main">System in a package</span> Electronic component

A system in a package (SiP) or system-in-package is a number of integrated circuits (ICs) enclosed in one chip carrier package or encompassing an IC package substrate that may include passive components and perform the functions of an entire system. The ICs may be stacked using package on package, placed side by side, and/or embedded in the substrate. The SiP performs all or most of the functions of an electronic system, and is typically used when designing components for mobile phones, digital music players, etc. Dies containing integrated circuits may be stacked vertically on the package substrate. They are internally connected by fine wires that are bonded to the package substrate. Alternatively, with a flip chip technology, solder bumps are used to join stacked chips together and to the package substrate, or even both techniques can be used in a single package. SiPs are like systems on a chip (SoCs) but less tightly integrated and not on a single semiconductor die.

<span class="mw-page-title-main">Tape-automated bonding</span> Places a microchip on a flexible circuit board

Tape-automated bonding (TAB) is a process that places bare semiconductor chips (dies) like integrated circuits onto a flexible circuit board (FPC) by attaching them to fine conductors in a polyamide or polyimide film carrier. This FPC with the die(s) can be mounted on the system or module board or assembled inside a package. Typically the FPC includes from one to three conductive layers and all inputs and outputs of the semiconductor die are connected simultaneously during the TAB bonding. Tape automated bonding is one of the methods needed for achieving chip-on-flex (COF) assembly and it is one of the first roll-to-roll processing type methods in the electronics manufacturing.

In semiconductor electronics fabrication technology, a self-aligned gate is a transistor manufacturing approach whereby the gate electrode of a MOSFET is used as a mask for the doping of the source and drain regions. This technique ensures that the gate is naturally and precisely aligned to the edges of the source and drain.

<span class="mw-page-title-main">Through-silicon via</span> Electrical connection

In electronic engineering, a through-silicon via (TSV) or through-chip via is a vertical electrical connection (via) that passes completely through a silicon wafer or die. TSVs are high-performance interconnect techniques used as an alternative to wire-bond and flip chips to create 3D packages and 3D integrated circuits. Compared to alternatives such as package-on-package, the interconnect and device density is substantially higher, and the length of the connections becomes shorter.

A three-dimensional integrated circuit is a MOS integrated circuit (IC) manufactured by stacking as many as 16 or more ICs and interconnecting them vertically using, for instance, through-silicon vias (TSVs) or Cu-Cu connections, so that they behave as a single device to achieve performance improvements at reduced power and smaller footprint than conventional two dimensional processes. The 3D IC is one of several 3D integration schemes that exploit the z-direction to achieve electrical performance benefits in microelectronics and nanoelectronics.

<span class="mw-page-title-main">Integrated passive devices</span>

Integrated passive devices (IPDs), also known as integrated passive components (IPCs) or embedded passive components (EPC), are electronic components where resistors (R), capacitors (C), inductors (L)/coils/chokes, microstriplines, impedance matching elements, baluns or any combinations of them are integrated in the same package or on the same substrate. Sometimes integrated passives can also be called as embedded passives, and still the difference between integrated and embedded passives is technically unclear. In both cases passives are realized in between dielectric layers or on the same substrate.

<span class="mw-page-title-main">Thick-film technology</span>

Thick-film technology is used to produce electronic devices/modules such as surface mount devices modules, hybrid integrated circuits, heating elements, integrated passive devices and sensors. Main manufacturing technique is screen printing (stenciling), which in addition to use in manufacturing electronic devices can also be used for various graphic reproduction targets. It became one of the key manufacturing/miniaturisation techniques of electronic devices/modules during 1950s. Typical film thickness – manufactured with thick film manufacturing processes for electronic devices – is 0.0001 to 0.1 mm.

Thermosonic bonding is widely used to wire bond silicon integrated circuits into computers. Alexander Coucoulas was named "Father of Thermosonic Bonding" by George Harman, the world's foremost authority on wire bonding, where he referenced Coucoulas's leading edge publications in his book, Wire Bonding In Microelectronics. Owing to the well proven reliability of thermosonic bonds, it is extensively used to connect the central processing units (CPUs), which are encapsulated silicon integrated circuits that serve as the "brains" of today's computers.

Thermocompression bonding describes a wafer bonding technique and is also referred to as diffusion bonding, pressure joining, thermocompression welding or solid-state welding. Two metals, e.g. gold-gold (Au), are brought into atomic contact applying force and heat simultaneously. The diffusion requires atomic contact between the surfaces due to the atomic motion. The atoms migrate from one crystal lattice to the other one based on crystal lattice vibration. This atomic interaction sticks the interface together. The diffusion process is described by the following three processes:

Cladding is the bonding together of dissimilar metals. It is different from fusion welding or gluing as a method to fasten the metals together. Cladding is often achieved by extruding two metals through a die as well as pressing or rolling sheets together under high pressure.

<span class="mw-page-title-main">Eutectic bonding</span>

Eutectic bonding, also referred to as eutectic soldering, describes a wafer bonding technique with an intermediate metal layer that can produce a eutectic system. Those eutectic metals are alloys that transform directly from solid to liquid state, or vice versa from liquid to solid state, at a specific composition and temperature without passing a two-phase equilibrium, i.e. liquid and solid state. The fact that the eutectic temperature can be much lower than the melting temperature of the two or more pure elements can be important in eutectic bonding.

The first planar monolithic integrated circuit (IC) chip was demonstrated in 1960. The idea of integrating electronic circuits into a single device was born when the German physicist and engineer Werner Jacobi developed and patented the first known integrated transistor amplifier in 1949 and the British radio engineer Geoffrey Dummer proposed to integrate a variety of standard electronic components in a monolithic semiconductor crystal in 1952. A year later, Harwick Johnson filed a patent for a prototype IC. Between 1953 and 1957, Sidney Darlington and Yasuo Tarui proposed similar chip designs where several transistors could share a common active area, but there was no electrical isolation to separate them from each other.

<span class="mw-page-title-main">Compliant bonding</span>

Compliant bonding is used to connect gold wires to electrical components such as integrated circuit "chips". It was invented by Alexander Coucoulas in the 1960s. The bond is formed well below the melting point of the mating gold surfaces and is therefore referred to as a solid-state type bond. The compliant bond is formed by transmitting heat and pressure to the bond region through a relatively thick indentable or compliant medium, generally an aluminum tape.

Glossary of microelectronics manufacturing terms

References

  1. ↑ Harman, G., Wire Bonding In Microelectronics, McGraw-Hill, Chapt. 2, pg.36, also search Coucoulas at https://www.amazon.com/WIRE-BONDING-MICROELECTRONICS-3-E/dp/0071476237/ref=sr_1_1?s=books&ie=UTF8&qid=1354948679&sr=1-1&keywords=wire+bonding+in+microelectronics#_ search Coucoulas
  2. 1 2 Coucoulas, A., Trans. Metallurgical Society of AIME, "Ultrasonic Welding of Aluminum Leads to Tantalum Thin Films", 1966, pp. 587–589. abstract https://sites.google.com/site/coucoulasthermosonicbondalta
  3. 1 2 3 Coucoulas, A., "Hot Work Ultrasonic Bonding – A Method Of Facilitating Metal Flow By Restoration Processes", Proc. 20th IEEE Electronic Components Conf. Washington, D.C., May 1970, pp. 549–556.https://sites.google.com/site/hotworkultrasonicbonding
  4. 1 2 3 Harman, G., Wire Bonding In Microelectronics, McGraw-Hill, 2010 ISBN   0-07-147623-7
  5. ↑ T.R. Reid, "The Chip: How Two Americans Invented the Microchip and Launched a Revolution"
  6. 1 2 A.Coucoulas, "Compliant Bonding" Proceedings 1970 IEEE 20th Electronic Components Conference, pp. 380-89, 1970.
  7. ↑ A.Coucoulas, Benzoni, A.M., Dautartas, M.F., Dutta, R., Holland, W.R., Nijander, C.R., Woods, R.E., AlO Bonding: A Method Of Joining Oxide Optical Components to Aluminum Coated Substrates, pp 471-481, Proceedings of the 43rd Electronic Components and Technology Conference, 1993, https://www.researchgate.net/publication/3565139_AlO_bonding_a_method_of_joining_oxide_optical_components_toaluminum_coated_substrates
  8. ↑ http://smithsonianchips.si.edu/patents/3533155.htm The Chip Collection – US Patent 3,533,155 – Smithsonian Institution smithsonianchips.si.edu/patents/3533155.htmCached United States Patent 3,533,155. October 13, 1970. Bonding With A Compliant Medium Alexander Coucoulas Filed July 6, 1967. Image of US PATENT 3,533,155
  9. 1 2 "Compression bonding methods".
  10. ↑ "Edgar Quinet Class".
  11. ↑ Dobkin, Marjorie Housepian. Smyrna 1922: The Destruction of a City. New York: Harcourt Brace Jovanovich, 1971; 2nd ed. Kent, Ohio: Kent State University Press, 1988, pp.102,174,117-121.
  12. ↑ K.L. Komarek, A. Coucoulas, and N. Klinger, Journal of the Electrochemical Society, V.110, No.7, July 1963 https://www.researchgate.net/publication/233854987_thesispublication
  13. ↑ F. Blaha, B. Langenecker. Acta Metallurgica, 7, 1957)
  14. ↑ Hagar, C (2000) Lifetime Estimation of Aluminum Wire Bonds based on Computational Plasticity, PhD thesis
  15. ↑ Burmeister, L.; et al. (1994). "Thermosonic bond contacts with gold wire to YBa2Cu3o7 microstructures". Superconductor Science and Technology. 7 (8): 569–572. Bibcode:1994SuScT...7..569B. doi:10.1088/0953-2048/7/8/006. S2CID   250794526.
  16. ↑ Harman, G., Wire Bonding In Microelectronics, McGraw-Hill, Ch. 2, p. 36
  17. ↑ Burmeister, L.; Reimer, D.; Schilling, M. (1994). "Thermosonic bond contacts with gold wire to YBa2Cu3O7 microstructures". Superconductor Science and Technology. 7 (8): 569–572. Bibcode:1994SuScT...7..569B. doi:10.1088/0953-2048/7/8/006. S2CID   250794526.
  18. ↑ Seck-Hoe Wong et al. (2006) "Packaging Of Power LEDs Using Thermosonic Bonding Of Au-Au Interconnects", Surface Mount Technology Association International Conference.
  19. ↑ http://smithsonianchips.si.edu/patents/3533155.htm The Chip Collection – US Patent 3,533,155 – Smithsonian Institution smithsonianchips.si.edu/patents/3533155.htmCached United States Patent 3,533,155. October 13, 1970. Bonding With A Compliant Medium Alexander Coucoulas Filed July 6, 1967. Image of US PATENT 3,533,155
  20. ↑ A. Coucoulas, Benzoni, A.M., Dautartas, M.F., Dutta, R., Holland, W.R., Nijander, C.R., Woods, R.E., AlO Bonding: A Method Of Joining Oxide Optical Components to Aluminum Coated Substrates, pp 471-481, Proceedings of the 43rd Electronic Components and Technology Conference, 1993 https://www.researchgate.net/publication/3565139_AlO_bonding_a_method_of_joining_oxide_optical_components_toaluminum_coated_substrates
  21. ↑ A. Coucoulas and E. Gregory, "Some Observations on the Microstructure and Fragmentation of Solid Carbon Dioxide", Transactions Of The Metallurgical Society of AIME (American Institute of Metallurgical Engineering), pg. 1134–42, volume 227, October 1963. https://www.researchgate.net/publication/229079078_Some_Observations_On_the_Microstructure_and_Fragmentation_of_Solid_Carbon_Dioxide
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.