| 31. |
- Fu, Yifeng, 1984, et al.
(författare)
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Application of through silicon via technology for in situ temperature monitoring on thermal interfaces
- 2010
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 1361-6439 .- 0960-1317. ; 20:2, s. id 025027 (5 pp)-
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a series of micro-machining processes have been developed to fabricate a test platform with the ability of in situ temperature monitoring on thermal interface behaviour. Through silicon vias (TSVs) with an aspect ratio up to 13 using Cu as a conductor have been applied to connect an array of platinum-based temperature sensors directly deposited on the thermal interfaces to be measured. The sensors are subsequently calibrated by an industry standard resistance temperature detector. Results show that the temperature sensors function normally in a temperature range up to 250 degrees C. This demonstrates the successful deposition of temperature-sensing materials and their good connection to the TSVs. The realization of direct precise temperature measurement on the thermal interface of this test platform enables thermal characterization with a high accuracy.
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| 32. |
- Fu, Yifeng, 1984, et al.
(författare)
-
Thick film patterning by lift-off process using double-coated single photoresists
- 2012
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Ingår i: Materials Letters. - : Elsevier BV. - 1873-4979 .- 0167-577X. ; 76, s. 117-119
-
Tidskriftsartikel (refereegranskat)abstract
- A novel method using lift-off process for patterning very thick materials is developed and demonstrated. Unlike conventional lift-off processes, no special lift-off resist is used in this method. Instead, only a double-coated single photoresist is needed. Demonstrations using two commercial photoresists show that good patterning morphology and obvious undercuts as high as 15 mu m are obtained for lift-off, which is very difficult to achieve by existing methods. The application and feasibility of this approach is demonstrated by a carbon nanotube transfer process. This simple and effective method offers wider option to pattern very thick materials in high quality which are in strong demands.
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| 33. |
- Fu, Yifeng, 1984, et al.
(författare)
-
Ultrafast Transfer of Metal Enhanced Carbon Nanotubes at Low Temperature for Large Scale Electronics Assembly
- 2010
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 22:44, s. 5039-5042
-
Tidskriftsartikel (refereegranskat)abstract
- An indium-assisted ultrafast carbon nanotube (CNT) transfer method with a yield rate over 90% is described. Metal-coated as-transferred CNT structures exhibit excellent electrical performance that is at least one order of magnitude better than the previously published results. Shear test results show that the adhesion between CNTs and the substrate is greatly improved and excellent flexibility is obtained after the transfer process.
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| 34. |
- 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
-
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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| 35. |
- Gao, Zhaoli, et al.
(författare)
-
Graphene Heat Spreader for Thermal Management of Hot Spots in Electronic Packaging
- 2012
-
Ingår i: Proceedings of the 18th Therminic International Workshop on Thermal Investigations of ICs and Systems. - 9782355000225 ; , s. 217-220
-
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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| 36. |
- Gao, Zhaoli, 1986, et al.
(författare)
-
Thermal chemical vapor deposition grown graphene heat spreader for thermal management of hot spots
- 2013
-
Ingår i: Carbon. - : Elsevier BV. - 0008-6223. ; 61, s. 342-348
-
Tidskriftsartikel (refereegranskat)abstract
- Graphene of different layer numbers was fabricated using thermal chemical vapor deposition (TCVD), and it was demonstrated as a heat spreader in electronic packaging. Platinum thermal evaluation chips were used to evaluate the thermal performance of the graphene heat spreaders. The temperature of a hot spot driven at a heat flux of up to 430 W cm(-2) was decreased from 121 degrees C to 108 degrees C (Delta T approximate to 13 degrees C) with the insertion of the monolayer graphene heat spreader, compared with the multilayer (n = 6-10) ones' temperature drop of similar to 8 degrees C. Various parameters affecting the thermal performance of graphene heat spreaders were discussed, e.g. layer numbers of graphene, phonon scattering, thermal boundary resistance. We demonstrate the potentials of using a complementary metal oxide semiconductor compatible TCVD process to utilize graphene as a heat spreader for heat dissipation purposes.
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| 37. |
- han, Hao xue, et al.
(författare)
-
Enhanced Heat Spreader Based on Few-Layer Graphene Intercalated With Silane-Functionalization Molecules
- 2014
-
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
-
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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| 38. |
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| 39. |
- Hu, Zhili, 1983, et al.
(författare)
-
Detecting single molecules inside a carbon nanotube to control molecular sequences using inertia trapping phenomenon
- 2012
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 101:13, s. Art. no. 133105-
-
Tidskriftsartikel (refereegranskat)abstract
- Here we show the detection of single gas molecules inside a carbon nanotube based on the change inresonance frequency and amplitude associated with the inertia trapping phenomenon. As its directimplication, a method for controlling the sequence of small molecule is then proposed to realize theconcept of manoeuvring of matter atom by atom in one dimension. The detection as well as theimplication is demonstrated numerically with the molecular dynamics method. It is theoreticallyassessed that it is possible for a physical model to be fabricated in the very near future.
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| 40. |
- Hu, Zhili, 1983, et al.
(författare)
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Influence of substrate on electrical conductivity of isotropic conductive adhesive
- 2011
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Ingår i: Proceedings of the IEEE International Symposium on Advanced Packaging Materials (APM), Xiamen, China, October 25-28, 2011. - 1550-5723. - 9781467301480 ; , s. 330 - 335
-
Konferensbidrag (refereegranskat)abstract
- Isotropic conductive adhesive (ICA) is widely used with different kinds of substrates in electronics packaging applications. Therefore it is necessary to understand the influence of electrical conductivity of ICA from substrate. In this work, we investigated the electrical resistivity of ICA on quartz, PCB and glass substrate. The experimental data showed that the in-plane electrical conductivity of ICA on PCB is almost twice that of the glass substrate, while the conductivity of ICA on quartz is also significantly greater than that of glass, under the same curing temperature and with the same bond line thickness (BLT) of ICA. This paper later concludes that thermal conductive adhesive (TCA) on substrate with higher thermal expansion coefficient (CTE) is likely to give better performance. Finally, Finite Element Modeling (FEM) and analysis shows that this phenomenon could be universal to ICA and TCA.
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