| 1. |
- Huang, Shirong, et al.
(författare)
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Infrared Emissivity Measurement for Vertically Aligned Multiwall Carbon Nanotubes (CNTs) Based Heat Spreader Applied in High Power Electronics Packaging
- 2016
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Ingår i: 6th Electronic System-integration Technology Conference (ESTC 2016). - 9781509014026 ; , s. Article no 7764696-
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Konferensbidrag (refereegranskat)abstract
- Vertically-aligned multiwall carbon nanotubes were deposited on silicon substrate by low pressure chemical vapor deposition (LPCVD), which can be utilized as heat spreaders in high power electronic packaging due to their remarkable thermal conductivity. The infrared emissivity of the vertically aligned multiwall carbon nanotubes was then characterized based on the FLIR SC600 infrared imaging system. The average infrared emissivity of the multiwall carbon nanotubes sample was about 0.92, which agrees well with experimental results reported before. Scanning electron microscopy (SEM) images of the multiwall carbon nanotubes were further analyzed to explain its high emissivity, and the reason can be attributed to the homogeneous sparseness and aligned structure of the vertically aligned multiwall carbon nanotubes
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| 2. |
- Huang, Shirong, et al.
(författare)
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Reliability of Graphene-based Films Used for High Power Electronics Packaging
- 2015
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Ingår i: 16th International Conference on Electronic Packaging Technology, ICEPT 2015, Changsha, China, 11-14 August 2015. - 9781467379991 ; , s. 852-855
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Konferensbidrag (refereegranskat)abstract
- Graphene-base film was fabricated with chemical conversion process, including graphene oxide (GO) prepared by Hummer's method, graphene oxide reduced with L-ascorbic acid (LAA), graphene based film deposited by vacuum filtration process. Meanwhile, the functionalization of the graphene-based film was performed to decrease the thermal interface resistance between the graphene-based film and substrate. Characterization data showed that the graphene-based film possessed high reliability after 500 hours under 85°C aging test. In summary, the graphene-based film can be a promising solution in thermal management of high power electronics.
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| 3. |
- Huang, Shirong, et al.
(författare)
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The Effects of Graphene-Based Films as Heat Spreaders for Thermal Management in Electronic Packaging
- 2016
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Ingår i: 2016 17th International Conference on Electronic Packaging Technology, ICEPT 2016. - 9781509013968 ; , s. Art no 7583272; Pages 889-892
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Konferensbidrag (refereegranskat)abstract
- Graphene-based films (GBF) were fabricated using a chemical conversion process including graphene oxide (GO) preparation by use of Hummer’s method, graphene oxide reduction using L-ascorbic acid (LAA), and finally film formation by vacuum filtration. GBF is considered as a candidate material for thermal management, i.e. for removing heat from hotspots in power electronic packaging, due to its high thermal conductivity. In this work, the GBF heat spreading performance in 3D TSV packaging was analysed using finite element methods (FEM) implemented in the COMSOL software. Both size effects and the influence of the thermal conductivity of the GBF heat spreader on the thermal performance of the 3D TSV package were evaluated. Furthermore, the size effects of the thermal conductive adhesive (TCA) underfill between the chip and the printed circuit board (PCB) were analysed. The results obtained are critical for proper design of graphene-based lateral heat spreaders in high power electronic packaging.
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| 4. |
- Biswas, Anis, et al.
(författare)
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The effect of oxygen partial pressure during deposition in the magnetic properties of ZnO thin film
- 2011
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Ingår i: Mater Res Soc Symp Proc. - : Springer Science and Business Media LLC. - 9781605112695 ; , s. 117-122
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Konferensbidrag (refereegranskat)abstract
- We have studied the magnetic properties of 100 nm thick ZnO thin films prepared by magnetron sputtering in different oxygen partial pressures (ratio of oxygen pressure to total pressure in deposition chamber, P Oxy). Only the films fabricated at P Oxy below ∼ 0.5 show room temperature ferromagnetism. The saturation magnetization at room temperature is initially found to increase as P Oxy increases and reaches maximum value of ∼ 5 emu/gm at P Oxy ∼ 0.3 and then starts to decrease and becomes diamagnetic for P Oxy > 0.5. From small angle XRD study of structural properties of the films, we find that the lattice stress developed in the film along c-axis also exhibits a similar behavior with the variation of P Oxy. Thus, both the room temperature ferromagnetism and lattice stress appear to originate from the intrinsic defects present in the sample.
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| 5. |
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| 6. |
- 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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| 7. |
- Singh, Bhanu Pratap, et al.
(författare)
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Analyzing the Impact of Die Positions inside the Power Module on the Reliability of Solder Layers for Different Power Cycling Scenarios
- 2023
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Ingår i: 2023 24th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2023. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- Solder layers, used as bonding material inside the power module to attach the semiconductor die on Direct Bond Copper (DBC) substrate and DBC substrate on baseplate, are one of the regions most prone to failure. The failure usually occurs in the form of solder cracks and depends on various operating conditions, such as-maximum temperature, temperature swing, and heating time. The cracks generated inside the solder layers can eventually result in its delamination. Power modules are usually power cycled to estimate the failure sites and mechanisms. However, the failure mechanisms can vary depending on the frequency, amplitude, and range of the temperature in the Power Cycling Tests (PCT). In this study, we have used the Finite Element Method (FEM) in COMSOL Multiphysics to analyse the impact of the PCT on both die attach, and baseplate attach solder layers. Additionally, the effect of the degree of asymmetry in the die position on the reliability of both the solder layers are analysed. The FEA (Finite Element Analysis) results are analysed to have a better understanding about the aspects impacting the lifetime of the power module.
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| 8. |
- Yuan, G., et al.
(författare)
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A brief overview of atomic layer deposition and etching in the semiconductor processing
- 2016
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Ingår i: 2016 17th International Conference on Electronic Packaging Technology, ICEPT 2016. - 9781509013968 ; , s. 1365-1368
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Konferensbidrag (refereegranskat)abstract
- Atomic layer deposition (ALD) and atomic layer etching (ALE) are two important techniques in the semiconductor processing, which focus ultra-Thin film deposition and etching, respectively. Both of them have the self-limiting surface behavior, and could realize the atomic-scale fidelity in the deposition and etching processes. Unlike traditional chemical vapor deposition (CVD) and physical vapor deposition (PVD), ALD has good step coverage, atomic-scale thickness controllability, and composition uniformity at low growth temperature. Compared with traditional continuous-wave plasma etching, ALE has smooth surface, excellent depth uniformity and atomic-scale thickness controllability. In this review, their fundamental and applications have been discussed.
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| 9. |
- Zhang, Dongsheng, et al.
(författare)
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Thermal properties of TIM using CNTs forest in electronics packaging
- 2016
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Ingår i: 2016 17th International Conference on Electronic Packaging Technology, ICEPT 2016; Wuhan Optics Valley Kingdom Hotel Wuhan; China; 16 August 2016 through 19 August 2016. ; , s. 1355-1359
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Konferensbidrag (refereegranskat)abstract
- Thermal interface material (TIM) is applied to fill the air gaps of interfaces, which provides a path for interfacial heat transfer. Owing to the exceptional thermal properties of carbon nanotubes (CNT), TIMs based on CNTs have received much attention in recent years. In this study, heat dissipation performance of vertically aligned carbon nanotubes (VACNT) arrays as TIM in electronic packing was analyzed. Vertically aligned carbon nanotubes with length of 245?m and 763?m were synthesized on a silicon substrate by chemical vapor deposition respectively. Morphology of the vertically aligned carbon nanotubes was characterized by scanning electron microscope. The hotspot temperature of thermal test chip with vertically aligned carbon nanotubes were characterized by resistance temperature detector method and infrared imaging method.
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| 10. |
- Zhang, Yan, et al.
(författare)
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Experimental investigation of paraffin wax with graphene enhancement as thermal management materials for batteries
- 2016
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Ingår i: 2016 17th International Conference on Electronic Packaging Technology, ICEPT 2016. - 9781509013968 ; , s. 1401-1405
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Konferensbidrag (refereegranskat)abstract
- Battery packs have been widely used as the power source in many fields, such as pure or hybrid electric vehicles, because of the advantages of high energy density, long cycle life, low self-discharge rate, no memory effect and so on. The heat dissipation is a key issue in the reliability of the batteries, especially for high power applications. Paraffin waxes are commonly used phase change materials in the thermal management of Li-ion battery packs. In order to improve the thermal performance, graphene powders are utilized as additives to increase the thermal conductivity of paraffin waxes. A series of graphene-enhanced paraffin wax samples are prepared, and then the prepared samples are applied to power sources for experimental evaluation. The results show an improved heat dissipation of paraffin waxes with graphene enhancement. Temperature rise in the heat source can be decreased, and the effect is more obvious for higher power case.
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