This paper presents a multi-scale modelling approach to investigate the underpinning mechanisms o... more This paper presents a multi-scale modelling approach to investigate the underpinning mechanisms of microstructure-sensitive damage of single crystal Sn-3Ag-0.5Cu (wt%, SAC305) solder joints of a Ball Grid Array (BGA) board assembly subject to thermal cycling. The multi-scale scheme couples board-scale modelling at the continuum macro-scale and individual solder modelling at the crystal micro-scale. Systematic studies of tin crystal orientation and its role in fatigue damage have been compared to experimental observations. Crystallographic orientation is examined with respect to damage development, providing evidence-based optimal solder microstructural design for in-service thermomechanical fatigue.
Surface mount assembly defects for thermally enhanced high I/O, BGAs can range from 0 to 20 ppmj ... more Surface mount assembly defects for thermally enhanced high I/O, BGAs can range from 0 to 20 ppmj with packages that meet the JEDEC coplanarity specification of 6 mils. Defect levels can be much higher for packages that exceed 6 mils, however. The ability to put surface mount components on both sides of the PWB is desirable in some applications. To
... References: 1. Erich, R., Development and Implementation of Shear Testing for Surface Mount ... more ... References: 1. Erich, R., Development and Implementation of Shear Testing for Surface Mount Area Array Technology, Thesis, Binghamton University, 1998. 2. Bradley, E., and Banerji, K., Effect of PCB finish on the Reliability and Wettability of Ball Grid Array Packages. ...
The majority of industrial lasers used in manufacturing are Class IV lasers. Engineering and admi... more The majority of industrial lasers used in manufacturing are Class IV lasers. Engineering and administrative control measures appropriate to that class of lasers must be enforced to ensure their safe use in production environments, i.e. they should be designed into Class 1 laser systems. In addition, several other design characteristics unique to industrial applications are normally incorporated into these Class I systems, such as interlocked enclosures, process monitoring by means of closed circuit television (CCTV) or microscope optics, and optical fibers as well as conventional, fixed optics for laser beam delivery. The accessible emission for an integrated production laser system must be below the Accessible Emission Limit for a Class I laser. This paper addresses solutions to safety design issues through examples of production industrial laser systems. The appropriate administrative control programs that complement the engineering control measures are also discussed.The majority of industrial lasers used in manufacturing are Class IV lasers. Engineering and administrative control measures appropriate to that class of lasers must be enforced to ensure their safe use in production environments, i.e. they should be designed into Class 1 laser systems. In addition, several other design characteristics unique to industrial applications are normally incorporated into these Class I systems, such as interlocked enclosures, process monitoring by means of closed circuit television (CCTV) or microscope optics, and optical fibers as well as conventional, fixed optics for laser beam delivery. The accessible emission for an integrated production laser system must be below the Accessible Emission Limit for a Class I laser. This paper addresses solutions to safety design issues through examples of production industrial laser systems. The appropriate administrative control programs that complement the engineering control measures are also discussed.
An excimer laser technique was developed to machine precision tap openings in a polymer-clad sili... more An excimer laser technique was developed to machine precision tap openings in a polymer-clad silica optical fiber for use in the construction of an optical backplane. In this technique, a telescope was used to image the laser beam onto the surface of the fiber at the desired tap location. The cladding then was removed using a prescribed number of pulses from the excimer laser. Single optical fiber taps were constructed using an ultraviolet-curable acralate to attach a tap fiber to a laser-machined opening in a central fiber. Tap measurements were made on single taps constructed from 650 × 350 micron elliptical openings and 250 micron diameter circular openings. Tap measurements also were made on a triple tap assembly which was fabricated using elliptical tap openings. The elliptical openings, with the major axis oriented along the longitudinal axis of the fiber, were determined to be more suitable for tap construction. The results of this study indicate that excimer laser machining is a promising technique for construction of a linear tapped bus for optical backplanes.
ABSTRACTLaser-assisted dry etching of lithium niobate, LiNbO3, as well as other electro-optic mat... more ABSTRACTLaser-assisted dry etching of lithium niobate, LiNbO3, as well as other electro-optic materials could be an industrially important process in the fabrication of optical waveguides. In this investigation, an excimer laser (ArF; 193nm) was used to conduct etching reactions using nitrogen trifluoride, NF3. Enhancement of etching was observed by comparing the etch rate for a gas assisted process with that of a purely photoablative process. Chemical analysis of the etched features via Auger electron spectroscopy and correlation of a simple rate equation with the experimental data revealed that lasersurface interactions are responsible for the laser-assisted etching process.
Electrolytic and electroless Ni/Au are common pad surface finishes on area array (BGA or CSP) pac... more Electrolytic and electroless Ni/Au are common pad surface finishes on area array (BGA or CSP) packages and printed wiring boards (PWB). The electroless nickel/immersion gold (ENIG) process often is implemented when there is insufficient space to allow bussing for the more common electrolytic Ni/Au plating. The ENIG process continues to be used despite evidence that it may cause or contribute to catastrophic, brittle, interfacial solder joint fractures. In this investigation a plastic ball grid array (PBGA) test vehicle is used to compare quality and reliability of four variations of the ENIG surface finish. The standard electrolytic Ni/Au surface finish is used as the control cell for the experiment. Ball shear tests and optical and scanning electron microscopy are performed on as-received and thermally preconditioned packages to evaluate package quality prior to assembly. Accelerated temperature cycling (0/+100 °C and-40/+125 °C) is used to evaluate solder joint attachment reliability. Detailed failure mode analysis is used to compare the fracture modes in the ball shear and thermal cycled samples in the electroless and electrolytic packages. The results are discussed in terms of the failure modes and the characteristics of the different Ni/Au surface finishes.
Critical alignments of single-mode laser packages have been secured using laser welds and resista... more Critical alignments of single-mode laser packages have been secured using laser welds and resistance welds. Two methods were used to ascertain submicron motions of the welded joints, which are caused primarily by stress relaxation: linear motion was measured by a Fraunhofer diffraction technique, and angular motion was measured by interferometry. Statistically significant groups of test joints were subjected to thermal
1995 Proceedings. 45th Electronic Components and Technology Conference
... VT Kowalskil, RJ Coylez, PP Solanz, andK. M. Hogan' ... The authors would like to thank ... more ... VT Kowalskil, RJ Coylez, PP Solanz, andK. M. Hogan' ... The authors would like to thank Stephen W. Granlund, Curtis A. Jack, Reinhard H. Kneer, Rory K. Schlenker, and C. Michael Schwenk of AT&T Mlcraelectranics for their cooperation and helpful discussions. REFERENCES ...
A common pad finish on area array (EGA or CSP) packages and printed wiring board (PWB) substrates... more A common pad finish on area array (EGA or CSP) packages and printed wiring board (PWB) substrates is Ni/Au, using either electrolytic or electroless deposition processes. Although both Ni /Au processes provide flat, solderable surface finishes, there are an increasing ...
Laser welding has gained increased attention as a manufacturing technique in industry [1–3]. Many... more Laser welding has gained increased attention as a manufacturing technique in industry [1–3]. Many of these applications require a detailed understanding of laser material interactions in order to control the weld penetration and extent of the heat affected zone (HAZ). To gain a better understanding of the welding process, it is desirable to generate an accurate mathematical model which can predict material behaviour and temperature profiles for various sets of laser parameters.Laser welding has gained increased attention as a manufacturing technique in industry [1–3]. Many of these applications require a detailed understanding of laser material interactions in order to control the weld penetration and extent of the heat affected zone (HAZ). To gain a better understanding of the welding process, it is desirable to generate an accurate mathematical model which can predict material behaviour and temperature profiles for various sets of laser parameters.
Twenty Third IEEE/CPMT International Electronics Manufacturing Technology Symposium (Cat. No.98CH36205)
... I/O Thermally Enhanced Ball Grid Array Packages RJ Coyle, TI Ejim, A. Holliday, PP Solan, and... more ... I/O Thermally Enhanced Ball Grid Array Packages RJ Coyle, TI Ejim, A. Holliday, PP Solan, and JK Dorey Lucent Technologies ... the following individuals from Lucent Technologies for their contributions: Rich Popovich for metallographic sample preparation, Ralph Stenerson for ...
IEEE Transactions on Components and Packaging Technologies, 2000
We investigated Intermetallic compound formation mechanisms and their effect on the integrity of ... more We investigated Intermetallic compound formation mechanisms and their effect on the integrity of ball grid array Cu/Ni/Au/solder joints integrity were investigated. Substrates with three types of Au plating, and thus three different thicknesses [ Electrolytic (2.6 and 0.75pm). Immersion (0.25pm), and Selective (0.02pm) ] were used. After solder reflow, the solder joints were annealed for up to 1000 hrs at 150°C. Optical and electronic metallography together with Energy Dispersive Spectroscopy were used to locate and identify phases present in the joint for different annealing times. Brittle failure of solder joints was ascribed to the formation of a ternary intermetallic (Auo.5Ni0.5)Snd at the interface solderhbstrate. In the absence of post-reflow thermal aging, only NiaSnd was observed at the interface and it did not decrease the mechanical reliability of the joint. Tensile-shear stress tests were performed on unaged samples as well as samples aged for 1 hr, 4 hrs and 450 hrs.
This paper presents a multi-scale modelling approach to investigate the underpinning mechanisms o... more This paper presents a multi-scale modelling approach to investigate the underpinning mechanisms of microstructure-sensitive damage of single crystal Sn-3Ag-0.5Cu (wt%, SAC305) solder joints of a Ball Grid Array (BGA) board assembly subject to thermal cycling. The multi-scale scheme couples board-scale modelling at the continuum macro-scale and individual solder modelling at the crystal micro-scale. Systematic studies of tin crystal orientation and its role in fatigue damage have been compared to experimental observations. Crystallographic orientation is examined with respect to damage development, providing evidence-based optimal solder microstructural design for in-service thermomechanical fatigue.
Surface mount assembly defects for thermally enhanced high I/O, BGAs can range from 0 to 20 ppmj ... more Surface mount assembly defects for thermally enhanced high I/O, BGAs can range from 0 to 20 ppmj with packages that meet the JEDEC coplanarity specification of 6 mils. Defect levels can be much higher for packages that exceed 6 mils, however. The ability to put surface mount components on both sides of the PWB is desirable in some applications. To
... References: 1. Erich, R., Development and Implementation of Shear Testing for Surface Mount ... more ... References: 1. Erich, R., Development and Implementation of Shear Testing for Surface Mount Area Array Technology, Thesis, Binghamton University, 1998. 2. Bradley, E., and Banerji, K., Effect of PCB finish on the Reliability and Wettability of Ball Grid Array Packages. ...
The majority of industrial lasers used in manufacturing are Class IV lasers. Engineering and admi... more The majority of industrial lasers used in manufacturing are Class IV lasers. Engineering and administrative control measures appropriate to that class of lasers must be enforced to ensure their safe use in production environments, i.e. they should be designed into Class 1 laser systems. In addition, several other design characteristics unique to industrial applications are normally incorporated into these Class I systems, such as interlocked enclosures, process monitoring by means of closed circuit television (CCTV) or microscope optics, and optical fibers as well as conventional, fixed optics for laser beam delivery. The accessible emission for an integrated production laser system must be below the Accessible Emission Limit for a Class I laser. This paper addresses solutions to safety design issues through examples of production industrial laser systems. The appropriate administrative control programs that complement the engineering control measures are also discussed.The majority of industrial lasers used in manufacturing are Class IV lasers. Engineering and administrative control measures appropriate to that class of lasers must be enforced to ensure their safe use in production environments, i.e. they should be designed into Class 1 laser systems. In addition, several other design characteristics unique to industrial applications are normally incorporated into these Class I systems, such as interlocked enclosures, process monitoring by means of closed circuit television (CCTV) or microscope optics, and optical fibers as well as conventional, fixed optics for laser beam delivery. The accessible emission for an integrated production laser system must be below the Accessible Emission Limit for a Class I laser. This paper addresses solutions to safety design issues through examples of production industrial laser systems. The appropriate administrative control programs that complement the engineering control measures are also discussed.
An excimer laser technique was developed to machine precision tap openings in a polymer-clad sili... more An excimer laser technique was developed to machine precision tap openings in a polymer-clad silica optical fiber for use in the construction of an optical backplane. In this technique, a telescope was used to image the laser beam onto the surface of the fiber at the desired tap location. The cladding then was removed using a prescribed number of pulses from the excimer laser. Single optical fiber taps were constructed using an ultraviolet-curable acralate to attach a tap fiber to a laser-machined opening in a central fiber. Tap measurements were made on single taps constructed from 650 × 350 micron elliptical openings and 250 micron diameter circular openings. Tap measurements also were made on a triple tap assembly which was fabricated using elliptical tap openings. The elliptical openings, with the major axis oriented along the longitudinal axis of the fiber, were determined to be more suitable for tap construction. The results of this study indicate that excimer laser machining is a promising technique for construction of a linear tapped bus for optical backplanes.
ABSTRACTLaser-assisted dry etching of lithium niobate, LiNbO3, as well as other electro-optic mat... more ABSTRACTLaser-assisted dry etching of lithium niobate, LiNbO3, as well as other electro-optic materials could be an industrially important process in the fabrication of optical waveguides. In this investigation, an excimer laser (ArF; 193nm) was used to conduct etching reactions using nitrogen trifluoride, NF3. Enhancement of etching was observed by comparing the etch rate for a gas assisted process with that of a purely photoablative process. Chemical analysis of the etched features via Auger electron spectroscopy and correlation of a simple rate equation with the experimental data revealed that lasersurface interactions are responsible for the laser-assisted etching process.
Electrolytic and electroless Ni/Au are common pad surface finishes on area array (BGA or CSP) pac... more Electrolytic and electroless Ni/Au are common pad surface finishes on area array (BGA or CSP) packages and printed wiring boards (PWB). The electroless nickel/immersion gold (ENIG) process often is implemented when there is insufficient space to allow bussing for the more common electrolytic Ni/Au plating. The ENIG process continues to be used despite evidence that it may cause or contribute to catastrophic, brittle, interfacial solder joint fractures. In this investigation a plastic ball grid array (PBGA) test vehicle is used to compare quality and reliability of four variations of the ENIG surface finish. The standard electrolytic Ni/Au surface finish is used as the control cell for the experiment. Ball shear tests and optical and scanning electron microscopy are performed on as-received and thermally preconditioned packages to evaluate package quality prior to assembly. Accelerated temperature cycling (0/+100 °C and-40/+125 °C) is used to evaluate solder joint attachment reliability. Detailed failure mode analysis is used to compare the fracture modes in the ball shear and thermal cycled samples in the electroless and electrolytic packages. The results are discussed in terms of the failure modes and the characteristics of the different Ni/Au surface finishes.
Critical alignments of single-mode laser packages have been secured using laser welds and resista... more Critical alignments of single-mode laser packages have been secured using laser welds and resistance welds. Two methods were used to ascertain submicron motions of the welded joints, which are caused primarily by stress relaxation: linear motion was measured by a Fraunhofer diffraction technique, and angular motion was measured by interferometry. Statistically significant groups of test joints were subjected to thermal
1995 Proceedings. 45th Electronic Components and Technology Conference
... VT Kowalskil, RJ Coylez, PP Solanz, andK. M. Hogan' ... The authors would like to thank ... more ... VT Kowalskil, RJ Coylez, PP Solanz, andK. M. Hogan' ... The authors would like to thank Stephen W. Granlund, Curtis A. Jack, Reinhard H. Kneer, Rory K. Schlenker, and C. Michael Schwenk of AT&T Mlcraelectranics for their cooperation and helpful discussions. REFERENCES ...
A common pad finish on area array (EGA or CSP) packages and printed wiring board (PWB) substrates... more A common pad finish on area array (EGA or CSP) packages and printed wiring board (PWB) substrates is Ni/Au, using either electrolytic or electroless deposition processes. Although both Ni /Au processes provide flat, solderable surface finishes, there are an increasing ...
Laser welding has gained increased attention as a manufacturing technique in industry [1–3]. Many... more Laser welding has gained increased attention as a manufacturing technique in industry [1–3]. Many of these applications require a detailed understanding of laser material interactions in order to control the weld penetration and extent of the heat affected zone (HAZ). To gain a better understanding of the welding process, it is desirable to generate an accurate mathematical model which can predict material behaviour and temperature profiles for various sets of laser parameters.Laser welding has gained increased attention as a manufacturing technique in industry [1–3]. Many of these applications require a detailed understanding of laser material interactions in order to control the weld penetration and extent of the heat affected zone (HAZ). To gain a better understanding of the welding process, it is desirable to generate an accurate mathematical model which can predict material behaviour and temperature profiles for various sets of laser parameters.
Twenty Third IEEE/CPMT International Electronics Manufacturing Technology Symposium (Cat. No.98CH36205)
... I/O Thermally Enhanced Ball Grid Array Packages RJ Coyle, TI Ejim, A. Holliday, PP Solan, and... more ... I/O Thermally Enhanced Ball Grid Array Packages RJ Coyle, TI Ejim, A. Holliday, PP Solan, and JK Dorey Lucent Technologies ... the following individuals from Lucent Technologies for their contributions: Rich Popovich for metallographic sample preparation, Ralph Stenerson for ...
IEEE Transactions on Components and Packaging Technologies, 2000
We investigated Intermetallic compound formation mechanisms and their effect on the integrity of ... more We investigated Intermetallic compound formation mechanisms and their effect on the integrity of ball grid array Cu/Ni/Au/solder joints integrity were investigated. Substrates with three types of Au plating, and thus three different thicknesses [ Electrolytic (2.6 and 0.75pm). Immersion (0.25pm), and Selective (0.02pm) ] were used. After solder reflow, the solder joints were annealed for up to 1000 hrs at 150°C. Optical and electronic metallography together with Energy Dispersive Spectroscopy were used to locate and identify phases present in the joint for different annealing times. Brittle failure of solder joints was ascribed to the formation of a ternary intermetallic (Auo.5Ni0.5)Snd at the interface solderhbstrate. In the absence of post-reflow thermal aging, only NiaSnd was observed at the interface and it did not decrease the mechanical reliability of the joint. Tensile-shear stress tests were performed on unaged samples as well as samples aged for 1 hr, 4 hrs and 450 hrs.
Uploads
Papers by Richard Coyle