| 21. |
- Jiang, Ziwei, et al.
(författare)
-
Characterterization of multi-scale nanosilver paste reinforced with SIC particles
- 2020
-
Ingår i: China Semiconductor Technology International Conference 2020, CSTIC 2020.
-
Konferensbidrag (refereegranskat)abstract
- Nanosilver paste with high operation temperature and low sintering temperature has attracted more and more attention for its promising application in high power devices. In this paper, the thermal properties of multi-scale nanosilver paste composed of nanometer and micrometer silver particles, and Ag-coated SiC particles were investigated. The thermal conductivity of multi-scale nanosilver paste increases with the increasing amount of SiC particles with Ag coating. The maximum value of Vickers hardness for multi-scale nanosilver paste with 0.5 wt.% Ag-coated SiC particles were 24.
|
|
| 22. |
- Lu, Pei, et al.
(författare)
-
Thermal Conduction of Fiber-Reinforced Polymer under Loading
- 2021
-
Ingår i: 2021 23rd European Microelectronics and Packaging Conference and Exhibition, EMPC 2021.
-
Konferensbidrag (refereegranskat)abstract
- Thermal performance of an epoxy resin reinforced by carbon fibers is studied by numerical simulation method. Various carbon fiber structures are taken into consideration and the effective thermal conductivity of the composite carbon fiber waved structure is obtained. The influences of the number, size, shape, spacing and arrangement of the carbon fibers on the thermal conduction of the composites are analyzed. The deformation of the composite under mechanical loading and the corresponding the thermal conductivity of the carbon fiber-reinforced epoxy resin are also investigated.
|
|
| 23. |
- Lv, Zhen, et al.
(författare)
-
Highly thermally conductive substrate based on graphene film
- 2021
-
Ingår i: 2021 23rd European Microelectronics and Packaging Conference and Exhibition, EMPC 2021. ; , s. 195-199
-
Konferensbidrag (refereegranskat)abstract
- Heat dissipation has become one of the critical challenges of development for microelectronic products because of the increasing of heat accumulation in the devices. A novel laminated composite with high thermal conductivity was fabricated by hot-pressing using graphene films (GFs) and glass fiber reinforced epoxy resin (GFEP). The effect of GFs with different thicknesses and number of layers on the thermal properties of the composites was investigated. An in-plane thermal conductivity of 141 W · m-1 · K-1 for the laminated composites with GFs and GFEP were obtained. The heat dissipation capability of GFs/GFEP composites is evaluated by infrared thermal imaging technology. The maximum temperature difference between the heating elements on GFs/GFEP composites and GFEP increases with the rise of voltage applied to the heating elements. Moreover, the heat dissipation capability of the composite is enhanced with the increased of the number of layers of GFs. The temperature of the heating element assembled on GFs/GFEP composites is 144.3°C lower than that on GFEP at the same voltage. The results indicate that the GFs/GFEP composites is a promising candidate of substrate material with high heat dissipation capability.
|
|
| 24. |
- Niu, Ziyu, et al.
(författare)
-
Enhanced electrochemical performance of three-dimensional graphene/carbon nanotube composite for supercapacitor application
- 2020
-
Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388. ; 820
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, we developed a facile route to synthesize three-dimensional graphene/carbon nanotube (3DG/CNT) hybrids as electrodes for binder-free electrical double layer capacitor (EDLC) by using chemical vapor deposition (CVD) method. The 3DG/CNT composites have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). It was found that the 3DG/CNT with interconnected architecture exhibit improved capacitive characteristic and electrical conductivity compared to that of pure 3DG. The 3DG/CNT composites have high specific capacitance of 197.2 F/g and excellent capacity retention rate of 93% after 1000 cycles. The experiment results show that the as-synthesized 3DG/CNT hold great potential as candidate as electrode for binder-free EDLC. © 2019 Elsevier B.V.
|
|
| 25. |
- Nylander, Andreas, 1988, et al.
(författare)
-
Degradation of Carbon Nanotube Array Thermal Interface Materials through Thermal Aging: Effects of Bonding, Array Height, and Catalyst Oxidation
- 2021
-
Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 13:26, s. 30992-31000
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon nanotube (CNT) array thermal interface materials (TIMs) are promising candidates for high-performance applications in terms of thermal performance. However, in order to be useful in commercial applications, the reliability of the interfaces is an equally important parameter, which so far has not been thoroughly investigated. In this study, the reliability of CNT array TIMs is investigated through accelerated aging. The roles of CNT array height and substrate configuration are studied for their relative impact on thermal resistance degradation. After aging, the CNT catalyst is analyzed using X-ray photoelectron spectroscopy to evaluate chemical changes. The CNT-catalyst bond appears to degrade during aging but not to the extent that the TIM performance is compromised. On the other hand, coefficient of thermal expansion mismatch between surfaces creates strain that needs to be absorbed, which requires CNT arrays with sufficient height. Transfer and bonding of both CNT roots and tips also create more reliable interfaces. Crucially, we find that the CNT array height of most previously reported CNT array TIMs is not enough to prevent significant reliability problems.
|
|
| 26. |
- Wang, Nan, 1988, et al.
(författare)
-
Improved Interfacial Bonding Strength and Reliability of Functionalized Graphene Oxide for Cement Reinforcement Applications
- 2020
-
Ingår i: Chemistry - A European Journal. - : Wiley. - 1521-3765 .- 0947-6539. ; 26:29, s. 6561-6568
-
Tidskriftsartikel (refereegranskat)abstract
- Poor bonding strength between nanomaterials and cement composites inevitably lead to the failure of reinforcement. Herein, a novel functionalization method for the fabrication of functionalized graphene oxide (FGO), which is capable of forming highly reliable covalent bonds with cement hydration products, and therefore, suitable for use as an efficient reinforcing agent for cement composites, is discussed. The bonding strength between cement and aggregates was improved more than 21 times with the reinforcement of FGO. The fabricated FGO also demonstrated many important features, including high reliability in cement pastes, good dispersibility, and efficient structural refinement of cement hydration products. With the incorporation of FGO, cement mortar samples demonstrated up to 40 % increased early and ultimate strength. Such results make the fast demolding and manufacture of light constructions become highly possible, and show strong advantages on improving productivity, saving cost, and reducing CO2 emissions in practical applications.
|
|
| 27. |
- Yang, Fei, et al.
(författare)
-
Thermal Properties of Laser-induced Graphene Films Photothermally Scribed on Bare Polyimide Substrates
- 2021
-
Ingår i: 2021 23rd European Microelectronics and Packaging Conference and Exhibition, EMPC 2021.
-
Konferensbidrag (refereegranskat)abstract
- In this work, laser-induced graphene (LIG)/polyimide (PI) films with good thermal properties were prepared by directly inducing graphene on the bare PI substrates by a computer numerical control (CNC) laser engraving machine. The obtained samples were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The results showed that the laser energy density has a significant impact on the microstructures of the samples. Moreover, the thermal diffusivity of LIG/PI was increased from 0.5 mm2/s to 1.6 mm2/s, which is 3 times higher than bare PI. Finally, the electrothermal properties of the LIG films were investigated and the results showed that under a 12 V power supply, the equilibrium temperature of LIG films increases from 45℃ to 74℃ with the increase of laser energy density from 1.8 J/mm2 to 2.4 J/mm2. Our results indicate that this time-saving, low-cost, and environment-friendly method is promising for fabricating excellent graphene-based materials.
|
|
| 28. |
- Yin, Hang, et al.
(författare)
-
Analysis of heat dissipation characteristics of three-dimensional graphene-carbon nanotube composite structures
- 2020
-
Ingår i: 2020 21ST INTERNATIONAL CONFERENCE ON ELECTRONIC PACKAGING TECHNOLOGY (ICEPT). - 9781728168265
-
Konferensbidrag (refereegranskat)abstract
- With the rapid development of electronic materials and technologies, the working frequencies of electronic components and devices have been greatly improved and the volume of electronic products has been shrinking. The integration density has increased significantly, which puts forward higher requirements for thermal management. One of the keys to the heat dissipation of electronic components is to transfer the heat rapidly to the radiator through the heat conducting medium. Therefore, the development of high conductive materials has become a research hotspot of high-density integrated devices and systems. Due to their excellent heat transfer properties, carbon nanomaterials such as carbon nanotube and graphene have attracted extensive attention. The thermal conductivities of carbon nanotube and graphene have obvious anisotropy, which limited their applications to some extent. In this paper, three-dimensional composite structures composed of graphene sheets and carbon nanotubes are considered. The heat transfer processes are simulated by molecular dynamics method and the heat transfer characteristics of van der Waals interaction and chemical bond structures are analyzed. The effects of heat flow and nanotube layout on the thermal properties of three-dimensional composite structures are discussed.
|
|
| 29. |
- Yu, Chen, et al.
(författare)
-
Thermal Properties of Laser Reduced Graphene Oxide Films
- 2021
-
Ingår i: 2021 23rd European Microelectronics and Packaging Conference and Exhibition, EMPC 2021.
-
Konferensbidrag (refereegranskat)abstract
- In recent years, laser-reduced graphene oxide (LRGO) has received widespread interest, however, the thermal properties of graphene films obtained by laser reduction of GO are rarely reported. In this paper, a pulsed laser was used to reduce the prepared GO films. The obtained LRGO films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS). The thermal diffusivity of the LRGO was measured as 7.3 mm2/s, higher than that of GO measured as 5.9 mm2/s. The heating performance of LRGO was performed under different DC voltages and the results show that the temperature can reach up to 91 ℃ with a response time of 14 s under the voltage of 18 V. The excellent electrothermal performance of LRGO films indicate that the LRGO films are promising as heating elements for various application such as defoggers.
|
|
| 30. |
- Yuan, G., et al.
(författare)
-
Thermally reduced graphene oxide/carbon nanotube composite films for thermal packaging applications
- 2020
-
Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 13:2
-
Tidskriftsartikel (refereegranskat)abstract
- Thermally reduced graphene oxide/carbon nanotube (rGO/CNT) composite films were successfully prepared by a high-temperature annealing process. Their microstructure, thermal conductivity and mechanical properties were systematically studied at different annealing temperatures. As the annealing temperature increased, more oxygen-containing functional groups were removed from the composite film, and the percentage of graphene continuously increased. When the annealing temperature increased from 1100 to 1400 °C, the thermal conductivity of the composite film also continuously increased from 673.9 to 1052.1 W m-1 K-1. Additionally, the Young's modulus was reduced by 63.6%, and the tensile strength was increased by 81.7%. In addition, the introduction of carbon nanotubes provided through-plane thermal conduction pathways for the composite films, which was beneficial for the improvement of their through-plane thermal conductivity. Furthermore, CNTs apparently improved the mechanical properties of rGO/CNT composite films. Compared with the rGO film, 1 wt% CNTs reduced the Young's modulus by 93.3% and increased the tensile strength of the rGO/CNT composite film by 60.3%, which could greatly improve its flexibility. Therefore, the rGO/CNT composite films show great potential for application as thermal interface materials (TIMs) due to their high in-plane thermal conductivity and good mechanical properties.
|
|
