All Outputs (14)

Three‐dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules (2019)
Journal Article
Agyakwa, P., Dai, J., Li, J., Mouawad, B., Yang, L., Corfield, M., & Johnson, C. (2019). Three‐dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules. Journal of Microscopy, 277(3), 140-153. https://doi.org/10.1111/jmi.12803

© 2019 The Authors. Journal of Microscopy published by John Wiley & Sons Ltd on behalf of Royal Microscopical Society. A time-lapse study of thermomechanical fatigue damage has been undertaken using three-dimensional X-ray computer tomography. Morp... Read More about Three‐dimensional damage morphologies of thermomechanically deformed sintered nanosilver die attachments for power electronics modules.

Comparative Thermal and Structural Characterization of Sintered Nano-Silver and High-Lead Solder Die Attachments During Power Cycling (2018)
Journal Article
Dai, J., Li, J., Agyakwa, P., Corfield, M., & Johnson, C. M. (2018). Comparative Thermal and Structural Characterization of Sintered Nano-Silver and High-Lead Solder Die Attachments During Power Cycling. IEEE Transactions on Device and Materials Reliability, 18(2), 256-265. https://doi.org/10.1109/TDMR.2018.2825386

13.5 mm × 13.5 mm sintered nano-silver attachments for power devices onto AlN substrates were prepared at 250 ºC and a pressure of 10MPa for 5 minutes and compared with Pb5Sn solder joint die attachments under constant current power cycling with an i... Read More about Comparative Thermal and Structural Characterization of Sintered Nano-Silver and High-Lead Solder Die Attachments During Power Cycling.

Comparison of thermal and reliability performance between a SiC MOSFET module with embedded decoupling capacitors and commercial Si IGBT power modules (2018)
Conference Proceeding
Yang, L., Agyakwa, P., Corfield, M., Johnson, M., Harris, A., Packwood, M., & Paciura, K. (2018). Comparison of thermal and reliability performance between a SiC MOSFET module with embedded decoupling capacitors and commercial Si IGBT power modules.

This paper characterizes thermal and reliability performance of a SiC MOSFET power module with embedded decoupling capacitors and without anti-parallel diodes. Active and passive temperature cycling, supported by transient thermal impedance character... Read More about Comparison of thermal and reliability performance between a SiC MOSFET module with embedded decoupling capacitors and commercial Si IGBT power modules.

Time-Efficient Sintering Processes to Attach Power Devices Using Nanosilver Dry Film (2017)
Journal Article
Dai, J., Li, J., Agyakwa, P., & Johnson, C. M. (2017). Time-Efficient Sintering Processes to Attach Power Devices Using Nanosilver Dry Film. Journal of Microelectronics and Electronic Packaging, 14(4), 140-149. https://doi.org/10.4071/imaps.521776

Pressure-assisted sintering processes to attach power devices using wet nanosilver pastes with time scales of minutes to a few hours have been widely reported. This paper presents our work on time-efficient sintering, using nanosilver dry film and an... Read More about Time-Efficient Sintering Processes to Attach Power Devices Using Nanosilver Dry Film.

Damage Evolution in Al Wire Bonds Subjected to a Junction Temperature Fluctuation of 30K (2016)
Journal Article
Agyakwa, P., Yang, L., Arjmand, E., Evans, P., Corfield, M., & Johnson, C. M. (2016). Damage Evolution in Al Wire Bonds Subjected to a Junction Temperature Fluctuation of 30K. Journal of Electronic Materials, 45, 3659-3672. https://doi.org/10.1007/s11664-016-4519-0

© 2016, The Author(s). Ultrasonically bonded heavy Al wires subjected to a small junction temperature fluctuation under power cycling from 40°C to 70°C were investigated using a non-destructive three-dimensional (3-D) x-ray tomography evaluation appr... Read More about Damage Evolution in Al Wire Bonds Subjected to a Junction Temperature Fluctuation of 30K.

Predicting Lifetime of Thick Al Wire Bonds Using Signals Obtained From Ultrasonic Generator (2016)
Journal Article
Arjmand, E., Agyakwa, P., Corfield, M., Li, J., & Johnson, C. M. (2016). Predicting Lifetime of Thick Al Wire Bonds Using Signals Obtained From Ultrasonic Generator. IEEE Transactions on Components, Packaging, and Manufacturing Technology, 6(5), 814-821. https://doi.org/10.1109/TCPMT.2016.2543001

Routine monitoring of the wire bonding process requires real-time evaluation and control of wire bond quality. In this paper, we present a nondestructive technique for detecting bond quality by the application of a semisupervised classification algor... Read More about Predicting Lifetime of Thick Al Wire Bonds Using Signals Obtained From Ultrasonic Generator.

Quantification of cracked area in thermal path of high-powermulti-chip modules using transient thermal impedance measurement (2016)
Journal Article
Eleffendi, M. A., Yang, L., Agyakwa, P., & Johnson, C. M. (2016). Quantification of cracked area in thermal path of high-powermulti-chip modules using transient thermal impedance measurement. Microelectronics Reliability, 59, https://doi.org/10.1016/j.microrel.2016.01.002

Transient thermal impedancemeasurement is commonly used to characterize the dynamic behaviour of the heat flowpath in power semiconductor packages. This can be used to derive a “structure function”which is a graphical representation of the internal s... Read More about Quantification of cracked area in thermal path of high-powermulti-chip modules using transient thermal impedance measurement.

A thermal cycling reliability study of ultrasonically bonded copper wires (2016)
Journal Article
Arjmand, E., Agyakwa, P. A., Corfield, M. R., Li, J., Mouawad, B., & Mark Johnson, C. (2016). A thermal cycling reliability study of ultrasonically bonded copper wires. Microelectronics Reliability, 59, https://doi.org/10.1016/j.microrel.2016.01.009

In this work we report on a reliability investigation regarding heavy copper wires ultrasonically bonded onto active braze copper substrates. The results obtained from both a non-destructive approach using 3D X-ray tomography and shear tests showed n... Read More about A thermal cycling reliability study of ultrasonically bonded copper wires.

Response to comments on “A numerical method to determine interdiffusion coefficients of Cu6Sn5 and Cu3Sn intermetallic compounds” (2015)
Journal Article
Li, J., Agyakwa, P. A., & Johnson, C. M. (2016). Response to comments on “A numerical method to determine interdiffusion coefficients of Cu6Sn5 and Cu3Sn intermetallic compounds”. Intermetallics, 69, https://doi.org/10.1016/j.intermet.2015.10.016

Comments have recently been made by Yuan et al. [1] to deny one statement in our paper [2], Eq. (21) in Wagner's paper [3] can be used to accurately calculate the integrated interdiffusion coefficient for an incremental diffusion couple only under th... Read More about Response to comments on “A numerical method to determine interdiffusion coefficients of Cu6Sn5 and Cu3Sn intermetallic compounds”.

Reliability of thick Al wire: a study of the effects of wire bonding parameters on thermal cycling degradation rate using non-destructive methods (2014)
Journal Article
Arjmand, E., Agyakwa, P. A., & Johnson, C. M. (2014). Reliability of thick Al wire: a study of the effects of wire bonding parameters on thermal cycling degradation rate using non-destructive methods. Microelectronics Reliability, 54(9-10), https://doi.org/10.1016/j.microrel.2014.07.119

The effect of bonding parameters on the reliability of thick Al wire bond is investigated. Samples were prepared with 25 different designs with 5 different bonding parameters such as time, ultrasonic power, begin- force, end-force and touch-down step... Read More about Reliability of thick Al wire: a study of the effects of wire bonding parameters on thermal cycling degradation rate using non-destructive methods.

Interdiffusion coefficients of binary multiphase systems with consideration of variation in Molar volumes (2014)
Journal Article
Li, J., Agyakwa, P., & Johnson, C. M. (2014). Interdiffusion coefficients of binary multiphase systems with consideration of variation in Molar volumes

This communication introduces a modification to the Wagner method to reveal and correct considerable systematic errors existing in the previously established analytical methods used to calculate the interdiffusion coefficients of binary multiphase sy... Read More about Interdiffusion coefficients of binary multiphase systems with consideration of variation in Molar volumes.

A non-destructive study of crack development during thermal cycling of Al wire bonds using x-ray computed tomography (2014)
Conference Proceeding
Agyakwa, P., Yang, L., Corfield, M., & Johnson, C. M. (2014). A non-destructive study of crack development during thermal cycling of Al wire bonds using x-ray computed tomography.

This paper concerns the non-destructive visualisation of the evolution of damage within ultrasonically bonded alumini-um wires using three dimensional x-ray computed tomography. We demonstrate the potential to observe the progressive accumulation of... Read More about A non-destructive study of crack development during thermal cycling of Al wire bonds using x-ray computed tomography.

Suitable Thicknesses of Base Metal and Interlayer, and Evolution of Phases for Ag/Sn/Ag Transient liquid-phase Joints Used for Power Die Attachment (2014)
Journal Article
Li, J., Agyakwa, P., & Johnson, C. (2014). Suitable Thicknesses of Base Metal and Interlayer, and Evolution of Phases for Ag/Sn/Ag Transient liquid-phase Joints Used for Power Die Attachment. Journal of Electronic Materials, 43(4), 983-995. https://doi.org/10.1007/s11664-013-2971-7

Real Si insulated gate bipolar transistors with conventional Ni/Ag metallization and dummy Si chips with thickened Ni/Ag metallization have both been bonded, at 250°C for 0 min, 40 min, and 640 min, to Ag foil electroplated with 2.7 μm and 6.8 μm thi... Read More about Suitable Thicknesses of Base Metal and Interlayer, and Evolution of Phases for Ag/Sn/Ag Transient liquid-phase Joints Used for Power Die Attachment.

Packaging/assembling technologies for a high performance SiC-based planar power module
Conference Proceeding
Li, J., Agyakwa, P., Evans, P., Johnson, C. M., Zhao, Y., Wu, Y., & Evans, K. (in press). Packaging/assembling technologies for a high performance SiC-based planar power module.

This work is to investigate the relevant packaging / assembling technologies for developing a SiC-based planar power module which is aimed to meet the requirements such as operating temperature of -60 °C to 200 °C, SiC devices connected to 540 V DC b... Read More about Packaging/assembling technologies for a high performance SiC-based planar power module.