Low-temperature and pressureless sinter joining of Cu with micron/submicron Ag particle paste in air

Zhang, Zheng; Chen, Chuantong; Yang, Yang; Zhang, Hao; Kim, Dong-Jin; Sugahara, Tohru; Nagao, Shijo; Suganuma, Katsuaki

doi:10.1016/j.jallcom.2018.11.251

Cited by 118 publications

(39 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is usually believed that the finer microstructure with smaller size of Ag grains benefits the mechanical strength of sintered Ag particles, which can be confirmed by the fact that ductile deformation is distinct and the fracture mainly happened at the sintered silver layer [14] . However, there is a certain competition between grain coarsening and porosity reduction not only during the sintering process but also in the service life at high temperatures.…”

Section: Conclusion and Discussionmentioning

confidence: 95%

“…Secondly, it is also found that the applied pressure during the sintering process can lead to less porosity and higher shear stress [11] ; nevertheless, the pressure may induce damage to some fragile components [12,13] . As for sintering temperature, Zhang et al [14] recently found that the shear strengths of the joints are 3.3, 7.6, 14.9, 30.0 and 20.7 MPa at the sintering temperatures of 180, 200, 220, 250 and 300 °C, respectively. Additionally, the fracture locations are at the interface with the substrate, within the sintered silver and at the interface with the chip when the joints are sintered at the temperatures of 180, 250 and 300 °C.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Correlation of microstructure and constitutive behaviour of sintered silver particles via nanoindentation

Long

Feng

et al. 2019

International Journal of Mechanical Sciences

View full text Add to dashboard Cite

During the sintering process, a three-dimensional network-like porous structure forms as the consequences of atom diffusion and neck formation among silver particles. In this paper, two representative types of pressureless sintered silver particles, i.e. , silver nanoparticles (AgNP) and silver microparticles (AgMP), are investigated to reveal the intrinsic correlation between microstructure and constitutive behaviour. The heterogeneous microstructure is found to result in distinguishing differences in terms of morphology and thermal stability. The difference of sintering mechanisms between these two types of silver pastes are observed by a scanning electron microscope and discussed. Regarding thermal stability, the effect of particle size and shape on the sintering temperature and mass loss are evaluated using the thermogravimetric analysis and the differential scanning calorimetry. The microstructural effect on the mechanical behaviour of both sintered AgNP and AgMP samples is measured by performing nanoindentations with a Berkovich indenter penetrated up to 2000 nm with different indentation strain rates. During indentation, Young's modulus and hardness are measured as the functions of penetration depth. By solving dimensionless equations, the parameters of a power-law constitutive model are obtained analytically based on the integrated work done in the loading stage and the contact stiffness in the unloading stage in the nanoindentation experiments. The correlation between microstructure and constitutive behaviour is elucidated by the comparison of sintered AgNP and AgMP but further investigations related to the size and shape effects of particles are expected.

show abstract

Section: Conclusion and Discussionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Correlation of microstructure and constitutive behaviour of sintered silver particles via nanoindentation

Long

Feng

et al. 2019

International Journal of Mechanical Sciences

View full text Add to dashboard Cite

show abstract

“…Although the metallization of Cu by using Ag or Au can improve the bondability, the bare Cu bonding is meaningful to reduce the cost and simplify the process. In fact, the bonding of bare Cu using Ag micro/nanoparticles in air is also challenged by the problem of interfacial oxidation, which weakens the bond strength and degrades the electrical characteristic of the joint [22]. Some strategies have been proposed that use an inert or reductive gas atmosphere [23,24] or coat the Cu surface by a single layer of graphene [25] to prevent the Cu surface from oxidation during the sintering bonding.…”

Section: Introductionmentioning

confidence: 99%

Robust Ag-Cu Sintering Bonding at 160 °C via Combining Ag2O Microparticle Paste and Pt-Catalyzed Formic Acid Vapor

et al. 2020

Metals

View full text Add to dashboard Cite

With the assistance of Pt-catalyzed formic acid vapor, robust Ag-Cu bonding was realized at an ultra-low temperature of 160 °C under 3 MPa for 30 min via the sintering of Ag nanoparticles in situ generated from Ag2O microparticles. The Cu oxide layer at the interface after bonding can be eliminated, which improves the bond strength and electrical conductivity of the joint. A metallic bond contact between the sintered Ag and the Cu substrate is obtained without interfacial solid solution and intermetallic phases, and the shear strength is comparable to previous bonding at a higher temperature. The bonding mechanisms were figured out by comparing the bonding with and without the Pt-catalyzed formic acid vapor. This ultra-low temperature Ag-Cu bonding method may create more flexibilities in the structure design and material selection for power device integration.

show abstract

“…Therefore, there have been some issues, for instance how to interconnect these multi-layers to implement in high temperature and have a thermal-stable reliability. In addition, power electronic substrate plays an important role in dissipating heat to prevent power electronic module failure [12,13,14,15,16,17,18]. Heat dissipation/insulation substrate, which is a direct bonded copper (DBC) and a direct bonded aluminum (DBA), are existed between power semiconductor device and heat sink.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Heat Dissipation and Thermal-Stability of Power Modules on DBC Substrates with Various Ceramics by SiC Micro-Heater Chip System and Ag Sinter Joining

et al. 2019

Self Cite

View full text Add to dashboard Cite

This study introduced the SiC micro-heater chip as a novel thermal evaluation device for next-generation power modules and to evaluate the heat resistant performance of direct bonded copper (DBC) substrate with aluminum nitride (AlN-DBC), aluminum oxide (DBC-Al2O3) and silicon nitride (Si3N4-DBC) ceramics middle layer. The SiC micro-heater chips were structurally sound bonded on the two types of DBC substrates by Ag sinter paste and Au wire was used to interconnect the SiC and DBC substrate. The SiC micro-heater chip power modules were fixed on a water-cooling plate by a thermal interface material (TIM), a steady-state thermal resistance measurement and a power cycling test were successfully conducted. As a result, the thermal resistance of the SiC micro-heater chip power modules on the DBC-Al2O3 substrate at power over 200 W was about twice higher than DBC-Si3N4 and also higher than DBC-AlN. In addition, during the power cycle test, DBC-Al2O3 was stopped after 1000 cycles due to Pt heater pattern line was partially broken induced by the excessive rise in thermal resistance, but DBC-Si3N4 and DBC-AlN specimens were subjected to more than 20,000 cycles and not noticeable physical failure was found in both of the SiC chip and DBC substrates by a x-ray observation. The results indicated that AlN-DBC can be as an optimization substrate for the best heat dissipation/durability in wide band-gap (WBG) power devices. Our results provide an important index for industries demanding higher power and temperature power electronics.

show abstract

Low-temperature and pressureless sinter joining of Cu with micron/submicron Ag particle paste in air

Cited by 118 publications

References 35 publications

Correlation of microstructure and constitutive behaviour of sintered silver particles via nanoindentation

Correlation of microstructure and constitutive behaviour of sintered silver particles via nanoindentation

Robust Ag-Cu Sintering Bonding at 160 °C via Combining Ag2O Microparticle Paste and Pt-Catalyzed Formic Acid Vapor

Measurement of Heat Dissipation and Thermal-Stability of Power Modules on DBC Substrates with Various Ceramics by SiC Micro-Heater Chip System and Ag Sinter Joining

Contact Info

Product

Resources

About