Simulating the Effect of Rigid Frameworks on the Mechanical Properties of Transient Liquid Phase Sintered (TLPS) Alloys

2021 ◽  
Vol 2021 (HiTEC) ◽  
pp. 000089-000093
Author(s):  
Gilad Nave ◽  
Patrick McCluskey
Keyword(s):  
Liquid Phase ◽  
Effective Properties ◽  
Mechanical Strain ◽  
Transient Liquid Phase ◽  
Hazardous Substances ◽  
Automotive Electronics ◽  
Plastic Energy ◽  
Brittle Behavior ◽  
Die Attach ◽  
Transmission Electron

Abstract The need for power electronic devices and materials that can operate in harsh environments, together with the Restriction of Hazardous Substances (RoHS) legislation, has driven industry and researchers to develop new attach materials. Transient Liquid Phase Sintered (TLPS) joints are strong candidates to replace the current die attach materials due to their superior mechanical, thermal, and electrical properties. Despite these qualities, current TLPS systems may exhibit stiff and brittle behavior that can lead to die or attach fracture under large thermomechanical strains during wide temperature range cycling, or under mechanical stress from shock and vibration loading, such as is experienced in automotive electronics. This paper presents an approach for reducing thermal and mechanical strain levels by incorporating Transmission Electron Microscopy (TEM) Cu grids as a reinforcement to the attach material. The grids serve as ductile reinforcement capable of absorbing elastic and plastic energy, and as a barrier for crack propagations through the relative brittle TLPS material. Homogenization calculations were used to evaluate the effective properties of the TLPS, followed by numerical analysis that shows the effect of the grids on the die attach structure, and the mechanical integrity of the design.

scholarly journals Evolution of Transient Liquid-Phase Sintered Cu–Sn Skeleton Microstructure During Thermal Aging

2019 ◽  
Vol 9 (1) ◽  
pp. 157 ◽  
Author(s):  
Hiroaki Tatsumi ◽  
Adrian Lis ◽  
Hiroshi Yamaguchi ◽  
Tomoki Matsuda ◽  
Tomokazu Sano ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Thermal Aging ◽  
Resin Composite ◽  
Transient Liquid Phase ◽  
Nitrogen Atmosphere ◽  
Sintering Process ◽  
Thermal Reliability ◽  
Cu6sn5 Phase ◽  
Die Attach ◽  
Negative Impacts

The evolution of the transient liquid-phase sintered (TLPS) Cu–Sn skeleton microstructure during thermal aging was evaluated to clarify the thermal reliability for die-attach applications. The Cu–Sn skeleton microstructure, which consists of Cu particles connected with Cu–Sn intermetallic compounds partially filled with polyimide resin, was obtained by the pressure-less TLP sintering process at 250 °C for 1 min using a novel Cu-solder-resin composite as a bonding material in a nitrogen atmosphere. Experimental results indicate that the TLPS joints were mainly composed of Cu, Cu6Sn5, and Cu3Sn in the as-bonded state, where submicron voids were observed at the interface between Cu3Sn and Cu particles. After thermal aging at 150, 175, and 200 °C for 1000 h, the Cu6Sn5 phase fully transformed into Cu3Sn except at the chip-side interface, where the number of the submicron voids appeared to increase. The averaged shear strengths were found to be 22.1 (reference), 22.8 (+3%), 24.0 (+9%), and 19.0 MPa (−14%) for the as-bonded state and specimens aged at 150, 175, and 200 °C for 1000 h, respectively. The TLPS joints maintained a shear strength over 19 MPa after thermal aging at 200 °C for 1000 h because of both the positive and negative impacts of the thermal aging, which include the transformation of Cu6Sn5 into Cu3Sn and the formation of submicron voids at the interface, respectively. These results indicate an excellent thermal reliability of the TLPS Cu–Sn skeleton microstructure.

Mechanical Characterization of Transient Liquid Phase Sintered (TLPS) Cu-Sn

2018 ◽  
Author(s):  
Erick Gutierrez ◽  
Subramani Manoharan ◽  
Maxim Serebreni ◽  
Patrick McCluskey
Keyword(s):  
Liquid Phase ◽  
Mechanical Load ◽  
Transient Liquid Phase ◽  
Electronic Systems ◽  
Power Electronic ◽  
Nano Indentation ◽  
Lap Shear ◽  
Die Attach ◽  
Power Modules

The increasing thermal demands in power electronic systems require the application of high temperature die attach materials. Transient Liquid Phase Sintered (TLPS) paste-based solder alloys have been demonstrated to effectively manage the thermal and mechanical load requirements of power modules. The microstructural features of these alloys provide interconnects with the necessary strength required to sustain high loads at high temperatures. To properly understand the influence of microstructure on mechanical behavior of these alloys, single lap shear experiments were performed on a TLPS system consisting of Copper and Tin particles (Cu-Sn). Nano-indentation measurements were performed on intermetallic phases of the TLPS, and the results obtained from lap shear testing and nano-indentation measurements are presented.

scholarly journals Deformation Behavior of Transient Liquid-Phase Sintered Cu-Solder-Resin Microstructure for Die-Attach

2019 ◽  
Vol 9 (17) ◽  
pp. 3476 ◽  
Author(s):  
Hiroaki Tatsumi ◽  
Hiroshi Yamaguchi ◽  
Tomoki Matsuda ◽  
Tomokazu Sano ◽  
Yoshihiro Kashiba ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Resin Composite ◽  
Copper Substrate ◽  
Transient Liquid Phase ◽  
Liquid Phase Sintering ◽  
Experimental Investigations ◽  
Uniaxial Tensile ◽  
Element Analysis ◽  
Die Attach ◽  
Deformation Properties

We have proposed a low-temperature bonding technology utilizing the sintering of Cu particles with transient liquid-phase of Sn-based solder, called transient liquid-phase sintering (TLPS), as a die-attach solution for high-temperature power modules. A copper-intermetallic compound-resin (Cu-IMC-resin) microstructure, which consists of Cu particles connected with Cu–Sn intermetallic compounds (IMCs) partially filled with polyimide resin, is obtained by the pressureless TLPS process at 250 °C for 1 min using a novel Cu-solder-resin composite as the bonding material in a nitrogen atmosphere. Macro- and micro-deformation properties of the unique microstructure of the TLPS Cu-IMC-resin are evaluated by finite element analysis using a three-dimensional image reconstruction model. The macroscopic computational uniaxial tensile tests of the Cu-IMC-resin model reveal that the utilization of the IMCs and the addition of the easily-deformable resin facilitates the temperature-stability and low-stiffness of the mechanical properties. The microstructure exhibits a significantly low homogenized Young’s modulus (11 GPa). Microscopic investigations show that the local stresses are broadly distributed on the IMC regions under uniaxial macroscopic tensile displacement, indicating highly reliable performance of the joint within a specific macroscopic strain condition. Numerical and experimental investigations demonstrate the excellent thermal cyclic reliability of die-attached joints between silicon carbide chips and directly bonded copper substrate.

Comparison of Au-In Transient Liquid Phase Bonding Designs for SiC Power Semiconductor Device Packaging

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000077-000083 ◽  
Author(s):  
Brian Grummel ◽  
Habib A. Mustain ◽  
Z. John Shen ◽  
Allen R. Hefner
Keyword(s):  
Liquid Phase ◽  
Semiconductor Device ◽  
Bonding Temperature ◽  
Transient Liquid Phase ◽  
Wide Bandgap ◽  
Thermal Reliability ◽  
Power Semiconductor ◽  
Tlp Bonding ◽  
Die Attach ◽  
Order Of Magnitude

Transient liquid phase (TLP) bonding is an advanced die-attach technique for wide-bandgap power semiconductor and high-temperature packaging. TLP bonding advances current soldering techniques by raising the melting point to over 500 °C without detrimental high-lead materials. The bond also has greater reliability and rigidity due in part to a bonding temperature of 200 °C that drastically lowers the peak bond stresses. Furthermore, the thermal conductivity is increased 67 % while the bond thickness is substantially reduced, lowering the thermal resistance by an order of magnitude. This work provides an in-depth examination of the TLP fabrication methodology utilizing mechanical and thermal experimental characterization data along with thermal reliability results.

Influence of Co-Doping on the Sintering Map of an Ultra Fine and Ultra Pure Alpha Alumina Powder

2006 ◽  
Vol 45 ◽  
pp. 55-60 ◽  
Author(s):  
Guillaume Bernard-Granger ◽  
Christian Guizard
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Liquid Phase ◽  
Transient Liquid Phase ◽  
Alumina Powder ◽  
Co Doping ◽  
Transmission Electron ◽  
The One ◽  
Alpha Alumina ◽  
Co Doped

The sintering map of an ultra fine and ultra pure α-alumina powder, doped with MO and DO2 (M for mono-valence cations, D for bi-valence cations), has been built from isothermal sintering experiments. It has been compared with the one obtained in a previous study with the same un-doped α-alumina raw powder. It seems that a transient liquid phase appears above a critical temperature in the co-doped material during sintering. It is proposed that this transient liquid phase is promoting densification and minimizing grain growth, as confirmed by transmission electron microscopy (TEM).

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