Because of their intrinsic design, bgas are technically complex to bond. Design methodology of high frequency ultrasonic transducer for wire. Wire bonding ultrasonic transducer system is composed of ultrasonic transducer and horn. Wire bonding is a solid phase welding process, where the two metallic materials wire and pad surface are brought into intimate contact. Impedance modeling of ultrasonic transducers used in heavy. In this study, we investigated the design of a wire wedge bonding ultrasonic tool horn using finite element method fem simulations. A new highfrequency ultrasonic transducer for wire bonding has been conceived, designed, prototyped and tested. Therefore, a proper bonding quality control system is desirable. Driver design of the piezoelectric ultrasonic transducer for. The sensor was a lead zirconate titanate pzt ring located in the middle of the langevin sandwich driver of a wire bonding transducer, where the electrode of the sensor was subdivided into several regions. Ultrasonic power features of wire bonding and thermosonic. Wire bonding is the method of making interconnections between an integrated circuit ic or other semiconductor device and its packaging during semiconductor device fabrication. Data logging software for model dpm3 load cell display, model ssi hand held display and model sst transmitters.
The bondjet bj855 meets the increasing demands of wire bonding and contributes to easy porting through smart functions such as the bondhead memory or the chip libraries. Development program 973 of china 2009cb724205, facility support of shanghai. Design of experiments approach for improving wire bonding. Dynamics of an ultrasonic transducer used for wire bonding.
Smart ultrasonic transducer for wirebonding applications. Dynamic characteristics of stacked piezoelectric transducers of. Wire bonder transducer arrangement and method national. Development program 973 of china 2009cb724205, facility support of shanghai wenhong. Based on the relationships among the dynamic resistance, impedance phase and resonant frequency of the transducer, the binary search algorithm had been used to automatically track the transducer resonance frequency. Investigation of ultrasonic vibrations of wirebonding.
Wire lengths of 6 mm are common, and loop shapes must be. Us8251275b2 ultrasonic transducers for wire bonding and. Special proprietary transducer for proper bond tool mounting. These are often the input factors one sees in a wire. The wire bonder bondjet bj653, with its changeable bondheads, serves the wire bonding processes of wedgewedge as well as ballwedge and can handle fine wire, heavy wire and ribbon. Design methodology of high frequency ultrasonic transducer. Study of temperature parameter in auag wire bonding. This is typically accomplished by a process known as ball bonding. The wire heated in some cases is pressed against the hot surface at 150 deg. Since the unloader stack already full, the worlaluck satianrangsarith and mongkol tirakanogsathit design of experiments approach for improving wire bonding quality international journal of innovation, management and technology, vol. Vibration simulation of transducer system in thermosonic.
High quality of the bonds is vital to the performance of an ic chip. This article is from sensors basel, switzerland, volume 9. Thermosonic bonding is widely used to wire bond silicon integrated circuits into computers. Typical applications for wire wire bonders are components in hf and rf technology, cob, mcm, hybrids, optical and automotive electronics. The bonding of the wire to the surface of a semiconductor chip is a di. The proposed method is based on an initial design estimate. Model 4500e series, motorized stepback wire bonders 0919. In this paper, an impedance model for the ultrasonic transducers is developed by analytical calculations using the equivalent circuit method. The ibond5000wedge is an advanced wedge bonder used for process development, production, research or added manufacturing support.
Vertical clearance is a full 046875 everywhere under these tool heads and all other mechanism except for wire presentation at 45 for angled feed. During the execution of the actual program during wire bonding, realtime. The ultrasonic transducer converts electrical energy into mechanical vibration, and its vibration characteristics have a great effect on the bonding quality. Yuen department of applied physics and materials research centre the hong kong polytechnic university, hunghom, kowloon. Our design team has the expertise and the resources to optimize all types of piezo sensor and piezo transducer.
Bond grid arrays bga application and the ability to decrease the temperature of the wire bonding process urgently demand higher bonding frequencies. Using design of experiments to optimize wire bond processes tj. Using stateoftheart interferometry measurement and fem modeling, information pertinent to a particular transducer system can be obtained and used as a guide to install sensor for automatic process control. The ultrasonic transducer working at 5 khz has been designed, simulated and tested. Model 4530e series, motorized stepback wire bonders. Aluminum wire bonding was performed on a lab testbed with pzt transducer device. Wire bonding dynamics monitoring by wavelet analysis. The wire must make a good electrical connection that will not degrade with time. Using design of experiments to optimize wire bond processes. Normally, ultrasonic energy is the most aggressive variable affecting bond pad failures, but poor design of the bond pads is also a root cause. The wire bond process wire bonding is an electrical interconnection technique using thin wire and a combination of heat, pressure andor ultrasonic energy. In order to design a driver of piezoelectric ultrasonic transducer which can provide high quality ultrasonic signal and be able to realize the frequency tracking rapidly, accurately and intelligently during the bonding process, the atmega128 microcontroller and ad9851 synthesizer are selected as core components to build an ultrasonic generator and frequency tracking system.
Performance study of an ultrasonic transducer used for. The palomar technologies 8000i wire bonder can perform standoff stitch sos. Owing to the well proven reliability of thermosonic bonds, it is. Sos is a program that interfaces with users to define a planar bump prior to crescent bond. The effect of ultrasonic frequency on gold wire bondability.
C or more at high force for a limited period of time to achieve the bond. Strain gauges have proven their value in the electrical measurement of mechanical quantities and play a fundamental role in the design of various transducers for force, pressure, or torque as well as load cells. Key software features for the 8000i wire bonder include adaptive bond deformation, enhanced loop mode, tailless ball bumping and wedge bond emulation chain bonding. It uses force, power, time, temperature, and ultrasonic energy sometimes referred to as bonding parameters to form both the ball and stitch bonds. The input impedance and power of pzt were investigated by using root mean square rms calculation. Pdf design of a smart ultrasonic transducer for interconnecting. Wire clamps are airopened and springclosed, and have selfcontained closure pivots. Bgas are designed for high io counts 225500 leads are common. State basic research development program of china no. This paper presents a new resonance tracking method for the piezoelectric ultrasonic transducer used in thermosonic wire bonding. Ultrasonic wire bonding is playing an important role in making interconnections in the microelectronics packaging industry. The ibond5000dual is an advanced ballwedge bonder used for process development, production, research or added manufacturing support.
This machine was revolutionary at its inception as the first to make a wire bond connection fully under. Usb connectivity external mouse, keyboard, disk on. Smart load cell systems buy online or call 8003443965. This video demonstrates a software analysis of the wire bonder transducer oscillation during wire bonding. The sensor was a lead zirconate titanate pzt ring located in the middle of the langevin sandwich driver of a wirebonding transducer, where the electrode of the sensor was subdivided into several regions. The gold wire bond technology is still widely used in back end assembly.
If the hb16 is used for gold wire bonding, heat is used as a fourth variable. Abstracta highfrequency ultrasonic transducer for copper or gold wire bonding has been designed. They guide the bonding wire to the face of the wedge bonding. Design and manufacture of an ultrasonic transducer for longterm high temperature operation mohammad hossein amini doctor of philosophy mechanical and industrial engineering, university of toronto 2016 abstract a novel design of ultrasonic transducers. Some preliminary work by us on using a piezoelectric. Experimenting with these parameters is time well spent, and is an important step toward developing a robust wire bond process. Potential wire bonding reliability concerns such as the tight. A sensor integrated in a smart ultrasonic transducer was used to monitor the bonding quality during wire bonding process.
The ibond5000 series integrates the proven 4500 manual wire bonder mechanical design with an advanced graphical user interface. Dynamic characteristics and ultrasonic properties of piezoelectric transducer determine the bonding quality in heavy aluminum wire bond packaging. Driver design of the piezoelectric ultrasonic transducer. Designedin reliability resulting from careful design of experiments and the development of internal design guidelines focused on. Piezocomposite ultrasonic transducers for highfrequency wire bonding of semiconductor packages are developed to alleviate the strong mode coupling and high mechanical quality factor intrinsic in piezoceramic transducers by using ringshaped lead zirconate titanate pztepoxy piezocomposites as the driving elements. Yuen department of applied physics and materials research centre the hong kong polytechnic university, hunghom, kowloon, hong kong.
Design and manufacture of an ultrasonic transducer for. Performance study of an ultrasonic transducer used for wire. In addition, a sensor integrated into the transducer allows process integrated quality control piqc on hesse wire bonders which captures multidimensional signal analyses of. For example, fine pitch packages software were used to record the velocity, voltage and current of transducer at different temperature settings. Surface cleanliness and bond pad metallurgy is critical. Gold wire bonding on lowk material small precision tools. This article shows the capability to suppress or reduce unwanted vertical vibrations using special control ide actuators and active vibration control. The force supports the plastic deformation and facilitates the coupling between the bonding tool, the wire and the substrate. Ultrasonic transducers for wire bonding and methods of forming wire bonds. Wire bonding is a solid state welding process, where two metallic materials are in intimate contact, and the rate of metallic interdiffusion is a function of temperature, force, ultrasonic power, and time.
Transducer suspension without tilt motion guarantees true vertical wedge tool at any time during processing. Problems associated with wire bonding are as follows. Ultrasonic energy is widely used in wire bonding for microelectronics packaging. Theromosonic wire bonding process and the ultrasonic transducer. Design of experiments doe four key inputs to the gold ball bonding process are ultrasonic transducer power, bond tool force, bond time, and stage heat. The effect of the temperature on bondability and bonding process for wire bonding are investigated. Model 4500e series, motorized stepback wire bonders last revised 091918 microscope prologue westbonds new e version starts the twentieth year of the model 4500 tradition. Investigation of ultrasonic vibrations of wirebonding capillaries z. Diagram of ultrasonic transducer used for wire bonding. Us8365977b2 ultrasonic transducers for wire bonding and. The approach to mount ultrasonic transducers on wire bonding.
A mechanically assembled nonbonded ultrasonic transducer includes a. In the design phase an advanced approach was used and established. The operating methods from manual to automatic bonding is particularly appropriate for the use in laboratories, in the development and for suppliers for validating. A new highfrequency ultrasonic transducer, in particular for the application wire bonding, has been conceived, designed, prototyped, and tested. Process quality improvement in thermosonic wire bonding. The outcome of altering the variables will be explained in the referenced chapters. As the transducer is moved, the bonding wire is fed through the capillary. The vibration driven by high frequency was tested by laser doppler vibrometer psv400m2. The results show that, transducer system of wire bonder works with its second combination vibration mode that includes three nodes axial vibration of concentrator and one node radial vibration of capillary. A laser doppler vibrometer and labview software were used to record the velocity, voltage and current of transducer at different temperature settings.
The earliest means of bonding wires to commercially produced silicon semiconductor devices involved tiny balls of solder that in essence soldered the wire to the chip. The driving voltage and current signals of piezoceramic transducer pzt were measured directly by designing circuits from ultrasonic generator and using a data acquisition software system. A new automatic resonance frequency tracking method for. Four key inputs to the gold ball bonding process are ultrasonic transducer power, bond tool force, bond time, and. A methodology is put forward for the design of high frequency ultrasonic transducer for wire bonding, which is based on the theory of the ultrasonic transducer, finite element method fem and. Although less common, wire bonding can be used to connect an ic to other electronics or to connect from one printed circuit board pcb to another. Small precision tools gold ball wire bonding process.
Bondability is characterized by shear bonding strength and bonding process is represented by input and output power of ultrasonic transducer. The ibond5000dual is an advanced ballwedge bonder used for process. For example, fine pitch packages transducer components, z1p and z2p are the equivalent impedances of piezoelectric ceramic stack, z11, z12 and z are the equivalent impedances of the back slab, z21, z22 and z23 are fi g. Design of ultrasonic tool horn for wire wedge bonding. A sensor integrated in a smart ultrasonic transducer was used to monitor the bonding quality during wirebonding process. Capacitive micromachined ultrasonic transducer design for high power transmission wafer bonded ultra sonic transducers use silicon as membrane and silicon oxide sio2 as insulation layer material 25.
Active vibration control in ultrasonic wire bonding. We are experienced in all aspects of transducer design from acoustics and damping to adhesive technology and we have the capability to fine tune piezo materials and to match drive circuitry to transducer characteristics for high performance in critical systems. The vibration simulation model of transducer system in wire bonding was established by mechanical finite element method and verified by electric sine sweeping exciting method. Performance study of an ultrasonic transducer used for wire bonding s. Piezocomposite ultrasonic transducers for highfrequency. Feb 27, 1996 this is typically accomplished by a process known as ball bonding. They demand fine pitch wire bonding pitch of 90 microns or less and require long wire lengths, straight loops, and small first and second bond areas. Hesse mechatronics partners with cad design software fremont, california, december 15, 2015 hesse mechatronics, inc. Design of experiments approach for improving wire bonding quality. Investigation of ultrasonic vibrations of wirebonding capillaries ntu. Design of a smart ultrasonic transducer for interconnecting. Alexander coucoulas was named father of thermosonic bonding by george harman, the worlds foremost authority on wire bonding, where he referenced coucoulass leading edge publications in his book, wire bonding in microelectronics. The design and dynamic analysis of high frequency ultrasonic.
At this point these parameters will be explained briefly. Chip scale package csp wire bonding capability study. A process which involves the use of force, time, and heat to join the two materials by interdiffusion. A new highfrequency ultrasonic transducer, in particular for the application wirebonding, has been conceived, designed, prototyped, and tested. The design of new ultrasonic transducers for wire bonding.
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