| 1. |
- Guo, Sihua, et al.
(författare)
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Toward ultrahigh thermal conductivity graphene films
- 2023
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Ingår i: 2D Materials. - : IOP Publishing. - 2053-1583. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- With increasing demands of high-performance and functionality, electronics devices generate a great amount of heat. Thus, efficient heat dissipation is crucially needed. Owing to its extremely good thermal conductivity, graphene is an interesting candidate for this purpose. In this paper, a two-step temperature-annealing process to fabricate ultrahigh thermal conductive graphene assembled films (GFs) is proposed. The thermal conductivity of the obtained GFs was as high as 3826 +/- 47 W m(-1) K-1. Extending the time of high-temperature annealing significantly improved the thermal performance of the GF. Structural analyses confirmed that the high thermal conductivity is caused by the large grain size, defect-free stacking, and high flatness, which are beneficial for phonon transmission in the carbon lattice. The turbostratic stacking degree decreased with increasing heat treatment time. However, the increase in the grain size after long heat treatment had a more pronounced effect on the phonon transfer of the GF than that of turbostratic stacking. The developed GFs show great potential for efficient thermal management in electronics devices.
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| 2. |
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| 3. |
- Huang, Shirong, et al.
(författare)
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Graphene Based Heat Spreader for High Power Chip Cooling Using Flip-chip Technology
- 2013
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Ingår i: 2013 IEEE 15th Electronics Packaging Technology Conference (EPTC 2013). - 9781479928330 ; , s. 347-352
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Konferensbidrag (refereegranskat)abstract
- Monolayer graphene was synthesized through thermal chemical vapor deposition (TCVD) as heat spreader for chip cooling. Platinum (Pt) serpentine functioned as hot spot on the thermal testing chip. The thermal testing chip with monolayer graphene film attached was bonded using flip-chip technology. The temperature at the hot spot with a monolayer graphene film as heat spreader was decreased by about 12°C and had a more uniform temperature compared to those without graphene heat spreader when driven by a heat flux of about 640W/cm 2 . Further improvements to the cooling performance of graphene heat spreader could be made by optimizing the synthesis parameters and transfer process of graphene films. © 2013 IEEE.
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| 4. |
- Zhang, Yong, 1982, et al.
(författare)
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2D HEAT DISSIPATION MATERIALS FOR MICROELECTRONICS COOLING APPLICATIONS
- 2016
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Ingår i: China Semiconductor Technology International Conference 2016, CSTIC 2016. - 9781467388047
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Konferensbidrag (refereegranskat)abstract
- The need for faster and smaller, as well as more reliable and efficient consumer electronic products has resulted in microelectronic components that produce progressively more heat. The resultant reliability issues from the increased heat flux are serious and hinder technological development. One solution for microelectronics cooling applications is 2D materials applied as heat spreaders and these include monolayer graphene, graphene based films, and monolayer hexagonal boron nitride and BN based films. In addition, thermal performances of the graphene heat spreader were also studied under different packaging structures, including wire bonding, cooling fins and flip chips. Finally, 2D hexagonal Boron nitride (h-BN) heat spreaders, fabricated by different methods, had their heat dissipation performances characterized by different thermal characterization methods, such as resistance temperature detector (RTD) and Infrared (IR) methods. In conclusion, these new novel 2D materials developed show great potential for microelectronics cooling applications.
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| 5. |
- Zhang, Yan, et al.
(författare)
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Study on the verification of IR and RTD methods applied in the thermal measurement of high power chips
- 2014
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Ingår i: 15th International Conference on Electronic Packaging Technology, ICEPT 2014; Wangjiang HotelChengdu; China; 12 August 2014 through 15 August 2014. - 9781479947072 ; , s. 1507-1511
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Konferensbidrag (refereegranskat)abstract
- In the present paper, a chip with a Pt-based RTD that functions as a heater and sensor is tested under serial power loads, and infrared (IR) thermal imaging system is adopted to obtain the thermal measurement. Comparisons of the hotspot temperatures of the chip obtained by RTD and IR methods have been made, where different surfaces of the chip were observed by the IR camera. Combing with the heat conduction law, the IR results of the test chip with surface preparation showed quite a good agreement with the RTD data, verifying the validation of the IR analysis method.
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| 6. |
- Zhang, Yong, 1982, et al.
(författare)
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Use of graphene-based films for hot spot cooling
- 2014
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Ingår i: Proceedings of the 5th Electronics System-Integration Technology Conference, ESTC 2014. - 9781479940264 ; , s. Art. no. 6962834-
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Konferensbidrag (refereegranskat)abstract
- Efficient heat dissipation is becoming an urgent demand in electronics and optoelectronics because of increasing power density, which is generating more heat than ever. Graphene, an atomic layer of carbon, has been shown to have high thermal conductivity, which makes this material a promising candidate for heat dissipation in electronics. Here, we demonstrate a new type of graphene-based film on a test platform to alleviate the thermal issues. Taking advantage of its high in-plane thermal conductivity, CVD-grown graphene has been observed to possess a strong heat-spreading ability. In this paper, a chemical conversion process, including chemical oxidation, exfoliation and reduction, is utilised to fabricate the graphene-based films. Additionally, functionalisation of the film was also performed to diminish the interface thermal resistance between the chip surface and the graphene-based films. Thermal characterisation showed a capacity for effective heat removal, which was indicated by the decrease in the hot spot temperature at the same power loading. In summary, this facile approach may technologically enable large-scale fabrication of graphene-based films for thermal management in high power density devices.
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| 7. |
- Bao, Jie, 1982, et al.
(författare)
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Two-dimensional hexagonal boron nitride as lateral heat spreader in electrically insulating packaging
- 2016
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Ingår i: Journal of Physics D: Applied Physics. - : IOP Publishing. - 1361-6463 .- 0022-3727. ; 49:July 2016, s. 265501-
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Tidskriftsartikel (refereegranskat)abstract
- The need for electrically insulating materials with a high in-plane thermal conductivity for lateral heat spreading applications in electronic devices has intensified studies of layered hexagonal boron nitride (h-BN) films. Due to its physicochemical properties, h-BN can be utilised in power dissipating devices such as an electrically insulating heat spreader material for laterally redistributing the heat from hotspots caused by locally excessive heat flux densities. In this study, two types of boron nitride based heat spreader test structures have been assembled and evaluated for heat dissipation. The test structures separately utilised a few-layer h-BN film with and without graphene enhancement drop coated onto the hotspot test structure. The influence of the h-BN heat spreader films on the temperature distribution across the surface of the hotspot test structure was studied at a range of heat flux densities through the hotspot. It was found that the graphene-enhanced h-BN film reduced the hotspot temperature by about 8–10°C at a 1000 W/cm2 heat flux density, a temperature decrease significantly larger than for h-BN film without graphene enhancement. Finite element simulations of the h-BN film predict that further improvements in heat spreading ability are possible if the thermal contact resistance between the film and test chip are minimised.
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| 8. |
- Gao, Zhaoli, 1986, et al.
(författare)
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Graphene Heat Spreader for Thermal Management of Hot Spots
- 2013
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. - 9781479902330 ; , s. 2075-2078
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Konferensbidrag (refereegranskat)abstract
- Monolayer graphene was fabricated using thermal chemical vapor deposition (TCVD) as heat spreaders in electronic packaging. Platinum (Pt) thermal evaluation chips were utilized to evaluate the thermal performance of the graphene heat spreaders. Temperature of hot spot driven at a heat flux of up to 430W·cm -2 was decreased by about 13 °C with the attaching of the graphene heat spreader. We demonstrate the potentials of using CMOS compatible TCVD process to make graphene as heat spreader for power dissipation needs. © 2013 IEEE.
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| 9. |
- Gao, Zhaoli, et al.
(författare)
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Graphene Heat Spreader for Thermal Management of Hot Spots in Electronic Packaging
- 2012
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Ingår i: Proceedings of the 18th Therminic International Workshop on Thermal Investigations of ICs and Systems. - 9782355000225 ; , s. 217-220
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Konferensbidrag (refereegranskat)abstract
- Monolayer graphene was fabricated using thermal CVD for the application of heat spreader in electronic packaging. Platinum (Pt) micro-heater embedded thermal testing chips were utilized to evaluate the thermal performance of the graphene heat spreader. The hot spot temperature was decreased by about 5 degrees C at a heat flux of up to 800W/cm2. It is possible to further improve the thermal performance of graphene heat spreader by optimizing the synthesis parameters and transfer process.
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| 10. |
- han, Hao xue, et al.
(författare)
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Enhanced Heat Spreader Based on Few-Layer Graphene Intercalated With Silane-Functionalization Molecules
- 2014
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Ingår i: IEEE 20th International Workshop on Thermal Investigation of ICs and Systems (Therminic). Greenwich, London, United Kingdom, 24-26 September 2014. - 9781479954155 ; , s. 1-4
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Konferensbidrag (refereegranskat)abstract
- We studied the heat-spreading enhancement of supported few-layer graphene by inserting silane-functionalization molecules between graphene sheets. We calculated the overall thermal resistance of graphene-substrate interface and the in-plane thermal conductivity of graphene sheets by equilibrium molecular dynamics simulations. We probed the spectral phonon transmission coefficient by non-equilibrium Green's function to characterize the local heat conduction through the interface. Our results show that the overal thermal resistance between the substrate graphene and the upper two-layer graphene underwent a three-fold increase by the presence of the molecules, while the local heat conduction from the hot spot to the graphene sheets through the molecules was largely intensified. Furthermore, the in-plane thermal conductivity of the few-layer graphene increased by 60% compared with the supported graphene non-bonded to the substrate through the molecules. This increase is attributed to the refrained cross-plane phonon scattering which in turn reinforces the in-plane heat conduction of the few-layer graphene. In summary, we proved that by inserting silane-functionalization molecules, the few-layer graphene becomes an ideal candidate for heat spreading by guiding heat more efficiently away from the heat source.
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