Normally, ultrasonic energy is the most aggressive variable affecting bond pad failures, but poor design of the bond pads is also a root cause. 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. 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. Smart ultrasonic transducer for wirebonding applications. 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.
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. 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. At this point these parameters will be explained briefly. Owing to the well proven reliability of thermosonic bonds, it is. 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. 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. Wire lengths of 6 mm are common, and loop shapes must be.
Us8365977b2 ultrasonic transducers for wire bonding and. Yuen department of applied physics and materials research centre the hong kong polytechnic university, hunghom, kowloon. 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. The proposed method is based on an initial design estimate.
A laser doppler vibrometer and labview software were used to record the velocity, voltage and current of transducer at different temperature settings. Typical applications for wire wire bonders are components in hf and rf technology, cob, mcm, hybrids, optical and automotive electronics. This paper presents a new resonance tracking method for the piezoelectric ultrasonic transducer used in thermosonic wire bonding. Because of their intrinsic design, bgas are technically complex to bond. Wire bonding is the method of making interconnections between an integrated circuit ic or other semiconductor device and its packaging during semiconductor device fabrication. Bondability is characterized by shear bonding strength and bonding process is represented by input and output power of ultrasonic transducer. Key software features for the 8000i wire bonder include adaptive bond deformation, enhanced loop mode, tailless ball bumping and wedge bond emulation chain bonding. The outcome of altering the variables will be explained in the referenced chapters. Theromosonic wire bonding process and the ultrasonic transducer. Design methodology of high frequency ultrasonic transducer for wire. 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 effect of ultrasonic frequency on gold wire bondability. Special proprietary transducer for proper bond tool mounting.
Ultrasonic energy is widely used in wire bonding for microelectronics packaging. Wire bonding ultrasonic transducer system is composed of ultrasonic transducer and horn. Us8251275b2 ultrasonic transducers for wire bonding and. A mechanically assembled nonbonded ultrasonic transducer includes a. Using design of experiments to optimize wire bond processes. Process quality improvement in thermosonic wire bonding. Wire bonding dynamics monitoring by wavelet analysis. Potential wire bonding reliability concerns such as the tight. Model 4530e series, motorized stepback wire bonders. A sensor integrated in a smart ultrasonic transducer was used to monitor the bonding quality during wirebonding process. Vibration simulation of transducer system in thermosonic. The effect of the temperature on bondability and bonding process for wire bonding are investigated. Design of a smart ultrasonic transducer for interconnecting.
This machine was revolutionary at its inception as the first to make a wire bond connection fully under. Ultrasonic power features of wire bonding and thermosonic. Dynamic characteristics of stacked piezoelectric transducers of. 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. The ibond5000wedge is an advanced wedge bonder used for process development, production, research or added manufacturing support. 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. A new highfrequency ultrasonic transducer for wire bonding has been conceived, designed, prototyped and tested.
If the hb16 is used for gold wire bonding, heat is used as a fourth variable. Wire bonder transducer arrangement and method national. This article is from sensors basel, switzerland, volume 9. Feb 27, 1996 this is typically accomplished by a process known as ball bonding.
Yuen department of applied physics and materials research centre the hong kong polytechnic university, hunghom, kowloon, hong kong. In this study, we investigated the design of a wire wedge bonding ultrasonic tool horn using finite element method fem simulations. During the execution of the actual program during wire bonding, realtime. 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. Our design team has the expertise and the resources to optimize all types of piezo sensor and piezo transducer. 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. 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. As the transducer is moved, the bonding wire is fed through the capillary.
The ibond5000 series integrates the proven 4500 manual wire bonder mechanical design with an advanced graphical user interface. The ultrasonic transducer converts electrical energy into mechanical vibration, and its vibration characteristics have a great effect on the bonding quality. The palomar technologies 8000i wire bonder can perform standoff stitch sos. Active vibration control in ultrasonic wire bonding.
The approach to mount ultrasonic transducers on wire bonding. Investigation of ultrasonic vibrations of wirebonding. Using design of experiments to optimize wire bond processes tj. A process which involves the use of force, time, and heat to join the two materials by interdiffusion. Impedance modeling of ultrasonic transducers used in heavy. State basic research development program of china no. Study of temperature parameter in auag wire 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. Wire bonding is a solid phase welding process, where the two metallic materials wire and pad surface are brought into intimate contact. A new highfrequency ultrasonic transducer, in particular for the application wire bonding, has been conceived, designed, prototyped, and tested. 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. 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.
Design and manufacture of an ultrasonic transducer for. 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. Performance study of an ultrasonic transducer used for wire. Investigation of ultrasonic vibrations of wirebonding capillaries ntu. Dynamics of an ultrasonic transducer used for wire bonding.
The operating methods from manual to automatic bonding is particularly appropriate for the use in laboratories, in the development and for suppliers for validating. Design methodology of high frequency ultrasonic transducer. Dynamic characteristics and ultrasonic properties of piezoelectric transducer determine the bonding quality in heavy aluminum wire bond packaging. Design of experiments approach for improving wire bonding quality. These are often the input factors one sees in a wire. This video demonstrates a software analysis of the wire bonder transducer oscillation during wire bonding. Model 4500e series, motorized stepback wire bonders 0919. Abstracta highfrequency ultrasonic transducer for copper or gold wire bonding has been designed.
Transducer suspension without tilt motion guarantees true vertical wedge tool at any time during processing. Aluminum wire bonding was performed on a lab testbed with pzt transducer device. In the design phase an advanced approach was used and established. Piezocomposite ultrasonic transducers for highfrequency. The ultrasonic transducer working at 5 khz has been designed, simulated and tested. 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. 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. Development program 973 of china 2009cb724205, facility support of shanghai. For example, fine pitch packages software were used to record the velocity, voltage and current of transducer at different temperature settings. Some preliminary work by us on using a piezoelectric. High quality of the bonds is vital to the performance of an ic chip.
A new automatic resonance frequency tracking method for. Smart load cell systems buy online or call 8003443965. The ibond5000dual is an advanced ballwedge bonder used for process. 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. Therefore, a proper bonding quality control system is desirable. The wire heated in some cases is pressed against the hot surface at 150 deg. Wire clamps are airopened and springclosed, and have selfcontained closure pivots.
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. Pdf design of a smart ultrasonic transducer for interconnecting. A new highfrequency ultrasonic transducer, in particular for the application wirebonding, has been conceived, designed, prototyped, and tested. Performance study of an ultrasonic transducer used for wire bonding s. In this paper, an impedance model for the ultrasonic transducers is developed by analytical calculations using the equivalent circuit method.
The design and dynamic analysis of high frequency ultrasonic. Vertical clearance is a full 046875 everywhere under these tool heads and all other mechanism except for wire presentation at 45 for angled feed. 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. Ultrasonic transducers for wire bonding and methods of forming wire bonds. The wire must make a good electrical connection that will not degrade with time.
The design of new ultrasonic transducers for wire bonding. They guide the bonding wire to the face of the wedge bonding. Design of experiments approach for improving wire bonding. Surface cleanliness and bond pad metallurgy is critical. Bgas are designed for high io counts 225500 leads are common. Driver design of the piezoelectric ultrasonic transducer for. This article shows the capability to suppress or reduce unwanted vertical vibrations using special control ide actuators and active vibration control.
Chip scale package csp wire bonding capability study. Bond grid arrays bga application and the ability to decrease the temperature of the wire bonding process urgently demand higher bonding frequencies. Data logging software for model dpm3 load cell display, model ssi hand held display and model sst transmitters. Designedin reliability resulting from careful design of experiments and the development of internal design guidelines focused on. The force supports the plastic deformation and facilitates the coupling between the bonding tool, the wire and the substrate. Development program 973 of china 2009cb724205, facility support of shanghai wenhong. Usb connectivity external mouse, keyboard, disk on. Problems associated with wire bonding are as follows.
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. The gold wire bond technology is still widely used in back end assembly. The wire bond process wire bonding is an electrical interconnection technique using thin wire and a combination of heat, pressure andor ultrasonic energy. The input impedance and power of pzt were investigated by using root mean square rms calculation. Four key inputs to the gold ball bonding process are ultrasonic transducer power, bond tool force, bond time, and. This is typically accomplished by a process known as ball bonding. Thermosonic bonding is widely used to wire bond silicon integrated circuits into computers. Ultrasonic wire bonding is playing an important role in making interconnections in the microelectronics packaging industry. The vibration driven by high frequency was tested by laser doppler vibrometer psv400m2. The bonding of the wire to the surface of a semiconductor chip is a di.
Diagram of ultrasonic transducer used for wire bonding. C or more at high force for a limited period of time to achieve the bond. Driver design of the piezoelectric ultrasonic transducer. Sos is a program that interfaces with users to define a planar bump prior to crescent bond. 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 wire bonding process.