| 1. |
- Amin, Muhammad, 1979, et al.
(författare)
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On-Chip Integrated Solid-State Micro-Supercapacitor
- 2017
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. ; , s. 173-178
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Konferensbidrag (refereegranskat)abstract
- Following the trend of electronic deviceminiaturization, on-chip integrated solid-state microsupercapcaitors (MS) were fabricated based on vertically aligned carbon nanofibers (VACNFs) as electrode materials and polymeric gel electrolyte as the solid electrolyte. The VACNFs were grown at 390 oC and 550 oC temperature on interdigitated micro-patterns, where the dimensions of the digits were kept the same but the gap between the digits varied from 10-100 micrometers. A maximum capacitance of 1 mF/cm2 and 0.53mF/cm2 (combined footprint area of digits and gaps) were measured for devices with CNFs grown at 390 oC and 20 m gap, for 550 oC and 10 m gap, respectively. Thesecapacitances are an order of magnitude higher than the one for solid dielectric based silicon trenches capacitors. The low temperature MS show an inverse capacitance relation with the gap size whereas high temperature shows random behavior.High characteristic frequencies at 45o phase angle are 114 Hz for 100 m gap and 142 Hz 30 m gap for 390 oC and 550 oC temperatures. A model for the interdigitated capacitors was developed and the results showed that by eliminating the current collector resistances the characteristic frequencies can be increased to 965 Hz and 866 Hz from 67 Hz and 127 Hz for 10 m gap patterns for 390 oC and 550 oC temperatures. The entire fabrication was done using CMOS compatible processes thus enabling integration directly on active CMOS chip.
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| 2. |
- Brinkfeldt, Klas, et al.
(författare)
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Thermal Simulations and Experimental Verification of Power Modules Designed for Double Sided Cooling
- 2016
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Ingår i: Electronic Components and Technology. - : Institute of Electrical and Electronics Engineers Inc.. - 0569-5503. ; , s. 1415-1422
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Tidskriftsartikel (refereegranskat)abstract
- Cooling power modules on both sides of the active switching devices reduces the operational junction temperature compared to conventional single sided cooling. In this work, thermal simulations of power modules based on single sided cooling concepts are compared with double sided cooling counterparts. Expected junction temperatures, maximum temperatures and maximum current capability is analyzed. In addition, experimental verification in the form of comparisons with thermal characterization tests for both single-And double sided power modules based on SiC bipolar junction transistors is presented. Results from simulations show that cooling of both sides of the active switching devices can reduce the thermal resistance by more than 40 percent. This number depends on the heat transfer coefficient. From one example, simulating a worst case stall condition of the electric machine, the use of double sided cooling reduces the maximum junction temperature from 167 °C to 106 °C at a load current of 300 A using a heat transfer coefficient of 4 kW/m2K and 4 kHz switching frequency. Furthermore, the temperature decreases to 97°C if AlN-based DBC substrates are used instead of alumina DBCs. Results from the experimental comparison between double-And single sided cooling showed that the maximum temperature for a load current range of 15 A to 50 A was reduced by 18 percent to 55 percent by using double sided cooling. At a device temperature of 60 °C, the increased thermal capability of the double sided version allowed for a 20 A higher load current, which corresponded to operation under 50 percent higher power losses. Double sided cooling also increased the maximum current capability through a single SiC BJT by more than 20 percent beyond the maximum current capability through the single sided cooling version.
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| 3. |
- 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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| 4. |
- Hansson, Josef, 1991, et al.
(författare)
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Synthesis of a Graphene Carbon Nanotube Hybrid Film by Joule Self-heating CVD for Thermal Applications
- 2018
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. ; 2018-May
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Konferensbidrag (refereegranskat)abstract
- Hybrid films based on vertically aligned carbon nanotubes (CNTs) on graphene or graphite sheets have been proposed for application as thermal interface materials and micro heat sinks. However, the fabrication of these materials are limited to small scale, expensive and complicated chemical vapor deposition (CVD) for CNT synthesis. We present a new method for direct growth of CNTs on one or both sides of a thin graphene film (GF) using joule self-heating of the graphene film to provide the necessary heat for the thermal breakdown of carbon feedstock in a CVD process. The resulting CNT forests show good density and alignment consistent with regular CVD synthesis processes on silicon surfaces. The resulting double sided GF/CNT hybrid film is directly applicable as a thermal pad. The CNT forest has a thermal conductivity of 30 W/mK, measured by pulsed photothermal reflectance, and the total thermal interface resistance between aluminum blocks was measured to be 60 Kmm 2 /W using an ASTM D5470 compliant 1-D measurement setup. This method of directly synthesizing CNTs on graphene films is more energy efficient and capable of larger volume production compared to traditional CVD methods. It is also compatible with scaling up towards continuous roll-to-roll production for large scale commercial production, one of the major limitations preventing CVD-grown CNTs from commercial applications
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| 5. |
- Liu, Johan, 1960, et al.
(författare)
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1. Thermal Characterization of Power Devices Using Graphene-based Film
- 2014
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. - 9781479924073 ; , s. 459 - 463
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Konferensbidrag (refereegranskat)abstract
- Due to its atomic structure with sp2 hybrid orbitals and unique electronic properties, graphene has an extraordinarily high thermal conductivity which has been reported to be up to 5000 W/mK. As a consequence, the use of graphene-based materials for thermal management has been subject to substantial attention during recent years in both academia and industry. In this paper, the development of a new type of graphene-based thin film for heat dissipation in power devices is presented. The surface of the developed graphene based film is primarily composed of functionalized graphene oxide, that can be bonded chemically to the device surface and thus minimize the interface thermal resistance caused by surface roughness. A very high in-plane thermal conductivity with a maximum value of 1600 W/mK was detected by laser flash machine regarding to the graphene-based films. To investigate the structure of the graphene-based films, scanning electron microscopy (SEM) and raman spectroscopy were carried out. Finally, LED demonstrators were built to illustrate the thermal performance of graphene-based film and the functional layers. IR camera recorded a 5°C lower temperature of a LED demonstrator with SHT G1000 as the binding layer instead of a commercial thermal conductive adhesive.
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| 6. |
- Liu, Johan, 1960, et al.
(författare)
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Stem Cell Growth and Migration on Nanofibrous Polymer Scaffolds and Micro-Fluidic Channels on Silicon-Chip
- 2009
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Ingår i: Proceedings of the 2009 Electronic Components and Technology Conference. - 0569-5503. - 9781424444762 ; , s. 1080-1085
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Konferensbidrag (refereegranskat)abstract
- Stem cell growth and migration on nanofibrous scaffolds and micro-fluidic channels on Silicon-Chip were studied by using neural stem cells isolated from adult rats' brain. Electrospinning and lithographic technique were used for developing nanofibrous-polylactic acid (PLA) and polyurethane (PU) based-scaffolds and micro-fluidic channels on Si-Chips respectively. Immunocytochemical and morphological analysis showed better cell-matrix interaction with profound adhesion, proliferation and migration on the developed scaffolds. Cell culture assay with microfluidic channel revealed the ability of developed channel system in guiding neuronal stem cell growth towards specified directions. These studies extend the possibility of using developed nanofibrous scaffolds and micro-fluidic channel system for future electrical signal transmission based on living neural stem cells.
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| 7. |
- Mu, Wei, 1985, et al.
(författare)
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Double-Densified VerticallyAligned Carbon Nanotube Bundles for Application in 3D Integration High Aspect Ratio TSV Interconnects
- 2016
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. - 9781509012046 ; 2016-August, s. 211-216
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Konferensbidrag (refereegranskat)abstract
- The treatment of densification by vapor on pristineMWCNT bundles are necessary to improve the effective area of the CNT TSV. However, the CNT bundles might tilt partly because of the non-uniform densification at root of the bundle, especially when it comes to the high aspect ratio CNT bundles. In order to solve these problems, a double densification process has been proposed and developed here. First of all, the shape of partial densified CNT bundles were optimized as a function of time. After several steps such as transferring of partial densified CNT bundles into the via, second densification, epoxy filling and chemical mechanical polishing, the CNT filled TSV with aspect ratio of 10 was achieved. The current voltage response of the CNT TSV interconnection indicated good electrical connection was formed. The resistivity of CNT bundles in via was calculated to be around 2-3 milli-ohmcm.
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| 8. |
- Rasilainen, Kimmo, 1987, et al.
(författare)
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Multi-Physical Simulations and Modelling of an Integrated GaN-on-Si Module Concept for Millimetre-Wave Communications
- 2020
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. ; 2020-June, s. 1369-1375
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Konferensbidrag (refereegranskat)abstract
- This paper presents a multi-physical system-level simulation workflow to characterise the performance of a heterogeneously integrated communications module for mm-wave applications. Basic principles behind modelling different parts and properties of the module are explained. The workflow combines the electromagnetic properties of a patch antenna array operating at 39 GHz with polynomial-based power amplifier (PA) models and thermal simulations of the structural heating. Effects of heating on the PA properties are also considered. The PA model is based on and compared with circuit simulations of a mm-wave transceiver chip, and the results are in good agreement. The proposed workflow can be used to describe and predict the performance of the module in different spatio-temporal use cases, and the approach also scales to larger arrays and more detailed simulation models.
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| 9. |
- Rasilainen, Kimmo, 1987, et al.
(författare)
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Thermal characteristics of vertically-integrated GaN/SiC-on-Si assemblies: A comparative study
- 2019
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. ; 2019-May, s. 1405-1412
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Konferensbidrag (refereegranskat)abstract
- This work investigates the thermal characteristics of a vertically-stacked, heterogeneously-integrated assembly intended for millimetre-wave communications systems. The assembly combines materials that enable the generation of high output power as well as high degree of integration for improved performance, and vertical integration of the different materials enables a compact footprint. Suitability of thermal solutions based on metal pillars, solder balls, and ball grid arrays (BGA) is investigated. Both ideal, fully-populated arrays of interconnects and partially-filled ones more suitable for practical implementations are considered using theoretical calculations and numerical thermal simulations. With the assumptions used, simulation results show that arrays of Cu pillars and large solder bumps with a pitch of 150 μm provide good thermal performance also with a simplified grid and reduced number of interconnects. In the current geometry, the most important locations for the pillars and bumps are near the heat sources, and the use of a rim of interconnects around the assembly perimeter can reduce the temperature by several degrees - even when the majority of the other interconnects is focused beneath the heat sources.
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| 10. |
- Sun, Shuangxi, 1986, et al.
(författare)
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Cooling hot spots by hexagonal boron nitride heat spreaders
- 2015
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. - 9781479986095 ; http://www.grapchina.com/Fhzt/view/id/96.html
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Konferensbidrag (refereegranskat)abstract
- As the electronic systems become smaller and faster, a thinner and higher-efficiency heat spreader is demanded to meet the thermal dissipation requirement. In this work, we proposed a layered hBN film based heat spreader to dissipate the thermal energy generated by hot spots on high power chips. The liquid phase exfoliation method was employed to synthesize hBN flakes. Different layers of hBN film were characterized using SEM, TEM and Raman spectroscopy. Afterwards, the films were directly attached onto the target power chips. The power chips were integrated with temperature sensor and hot spot in order to analyze the thermal performance of the hBN heat spreader. IR Camera was used to capture the heat spreading effect of the hBN heat spreader and monitor the temperature distribution around the hot spot. The temperature at the hot spot driven by a heat flux of around 600W/cm2 was decreased by about 20% compared to the sample without the BN film. The potential of using hBN heat spreader for cooling hot spots was demonstrated in this work.
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| 11. |
- Sun, S., et al.
(författare)
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Thermal performance characterization of nano thermal interface materials after power cycling
- 2012
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. - 9781467319669 ; , s. 1426-1430
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Konferensbidrag (refereegranskat)abstract
- The need for faster, smaller, and more reliable and efficient products has resulted in increase of heat generated in microelectronic components. The removal of the heat generated is an important issue in electronic packaging. A novel Nano-TIM was developed to improve the heat dissipation of electronics packaging. This paper aims at studying the heat dissipation performance of a new class of nano-structured polymer-metal composite film (Nano-TIM) after power cycling. The new Nano-TIM uses metal to provide continuous thermal pathways while using nano-polymer to control the elasticity of the TIM. Through semiconductor processing and RTD principle, chips including 5*5, 10*10, 20*20, 30*30 (mm 2), were developed to study different size's influence on heat dissipation effect of the Nano-TIM. Additional parameters studied include power effect. RTD is used respectively to measure the junction temperature, and then the R thJC (Junction-to-Case Thermal Resistance) is calculated afterwards. The Transient thermal resistances of the Nano-TIM were also tested by T3Ster method to further study heat dissipation effect of Nano-TIM. The morphologies and interaction between the Nano-TIM and chips were carefully studied using X-ray Scanning Microscope to analyze heat flow path. The result shows that Nano-TIMs can be used to 30 mm in chip length as the thermal interface material.
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| 12. |
- Tang, X., et al.
(författare)
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Development and characterisation of nanofiber films with high adhesion
- 2011
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. ; , s. 673-677
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Konferensbidrag (refereegranskat)abstract
- With the development of thermal management, thermal interface material (TIM) plays a more and more important role in electronic packaging. This paper reports the study on fabrication of a nanofiber films used for nano-thermal interface material (nano-TIM) with the adhesive function. The nano-TIM with high thermal conductivity and low thermal resistivity has been fabricated by electrospinning process. In the present work, hotmelt was added into the electrospinning solution to improve the adhesion properties of the film. The morphology of the film was observed by Scanning Electrical Microscope (SEM). The nanofiber films have a nano-scale structure with hotmelt randomly attached into the fiber matrix. Shear tests were conducted to measure the bonding strength of nanofiber films. The results show that the nanofiber films reached a 6.52 MPa in terms of average shear strength, more than 2 times better than the case without the hotmelt addition. © 2011 IEEE.
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| 13. |
- Wang, Nan, et al.
(författare)
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Highly thermal conductive and electrically insulated graphene based thermal interface material with long-term reliability
- 2019
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. ; 2019-May, s. 1564-1568
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Konferensbidrag (refereegranskat)abstract
- High density packaging in combination with increased transistor integration inevitably leads to challenging power densities in terms of thermal management. The conventional TIMs that are widely used in the microelectronic industry today are experiencing more and more stress due to their limited thermal performance and poor reliability. Composed by particle laden polymer matrix, thermal conductivity (K) of conventional TIMs is generally limited to 5 W/mK, and such values can be even lower for electrically insulated TIMs. Conventional TIMs also suffer from severe pump-out and dry-out failures, which brought great threat to the performance and lifetime of the electronic devices. Here, we solve these problems by applying a novel highly thermal conductive, electrically insulated and reliable graphene based TIMs (I-GTs). Composed by vertical graphene structures, I-GTs provide a continuous heat pathway from top to bottom, which enables superfast heat dissipation at through-plane direction. The highest bulk through-plane thermal conductivity of the conductive body can reach up to 1000 W/mK, which is orders of magnitude higher than conventional TIMs, and even outperforms the pure indium TIMs by over ten times. The highly flexible and foldable nature of I-GT enables at least 100% compressibility upon small applied pressures. As excellent gap fillers, I-GT can provide complete physical contact between two surfaces and thereby minimize the contact resistance to heat flow. The measured minimum thermal resistance for I-GTs reaches about 30 Kmm2/W. Such values are significantly higher than the randomly dispersed composites presented above. To ensure fully electrical insulation, a smooth and soft adhesive layer with a thickness of few microns was coated on the surface of I-GT. The breakdown voltage of I-GT reaches up to 950 V. Thermal cycling test shows the highly stable nature of I-GT. The good compressibility and elasticity of I-GT ensures continued proper TIM contact with substrates, which counteracts the effect of internal stress induced by the mismatch of coefficient of thermal expansion (CTE) during temperature cycling. In addition, the I-GTs have the advantages of low density and good maintainability. The resulting I-GTs thus opens new opportunities for addressing large heat dissipation issues for form-factor driven electronics and other high power driven systems.
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| 14. |
- Wu, Kuan-Hsun, et al.
(författare)
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Considerations of SiP based Antenna in Package/Module (AiP/AiM) Design at Sub-Terahertz Frequencies for Potential B5G/6G Applications
- 2021
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Ingår i: Proceedings - Electronic Components and Technology Conference. - 0569-5503. ; 2021-June, s. 1162-1168
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Konferensbidrag (refereegranskat)abstract
- Antenna-in-Package/Module (AiP/AiM) are the primary technologies to realize the RF subsystems for frequencies beyond millimeter-wave (mmW) bands, including sub-terahertz for potential B5G/6G applications. Due to the small wavelength, the mechanical process of the current system-in-package (SiP) results in limitations to realize antenna arrays at sub-terahertz. In this paper, the mechanical limits to cause radiation discrepancy is investigated by designing an AiP/AiM at 110 GHz band. Through the parametric studies based on the currently available cheap SiP process, one may summarize the considerations of AiP/AiM design for beyond sub-terahertz frequencies. The examination will consider the design of an 8x8 antenna array to provide a radiation gain of 20 dBi. Numerical full-wave simulations by HFSS were performed to obtain reliable behaviors of AiP/AiM radiations.
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