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- Lai, H., et al.
(författare)
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A novel isotropic conductive adhesive with Ag flakes, BN and SiC nanoparticles
- 2010
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Ingår i: 2010 International Symposium on Advanced Packaging Materials: Microtech, APM '10. - 9781424467563 ; , s. 49-53
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Isotropic conductive adhesives (ICAs) with lower bonding temperature, higher resolution and environmental friendly have been used extensively in packaging process. In order to improve the electrical and thermal conductive properties of ICAs, two kinds of bimodal high temperature stable ICAs with matrix SHT6 and fillers with composition of macro silver flakes and boron nitride nanoparticles or macro silver flakes and silicon carbide nanoparticles were studied. In these two kinds of adhesives, the silver flakes were 75wt%, and the contents of nanoparticles were Owt%, 0.5wt%, 1.5wt%, 2.5wt%, 3wt%, 5wt% in weight. All the samples were cured at 150°C for 1 hour. SEM images and EDS results show the nanoparticles disperse randomly in the ICA. The electrical resistivity of these ICAs depends on the contents of silver flakes and is hardly affected by BN nanoparticles and SiC nanoparticles. The thermal conductivity of these ICAs increases firstly with the weight increase of the BN nanoparticles and SiC nanoparticles. And then it decreases when the content of the nanoparticles beyond a certain point. ©2010 IEEE.
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| 2. |
- Luo, Xin, 1983, et al.
(författare)
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Surface oxide analysis of lead-free solder particles
- 2013
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Ingår i: Soldering and Surface Mount Technology. - : Emerald. - 1758-6836 .- 0954-0911. ; 25:1, s. 39-44
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Tidskriftsartikel (refereegranskat)abstract
- Purpose - The composition and thickness of surface oxide of solder particles is extremely important to the quality of interconnect and reliability of packaged system. The purpose of this paper is to develop an observable measurement to research the issue. Design/methodology/approach - AES (Auger electron spectroscopy), XPS (X-ray photoelectron spectroscopy), TEM (transmission electron microscopy) and STEM (scanning transmission electron microscopy) were employed to examine the oxide layer on microscale solder powders. Conventional techniques and FIB (Focus Ion Beam) were employed for the TEM sample preparation. High angle annular dark field (HAADF) pattern was applied to distinguish the oxide layer and the solder matrix by the contrast of average atomic number. The results were confirmed by AES and XPS measurement. Findings - The solder powders were exposed to air (70% relative humidity) at 150 degrees C for 0, 120 and 240 h for the accelerated growth of oxide. The surface oxide thickness was 6 nm and 50 nm measured by TEM for Oh and 120 h samples, respectively. It was found that the increase in surface oxide thickness of solder particles is proportional to the rooting of time. The elemental distribution along the oxide was quantified by line scanning using STEM and the atomic ratio of Sn to O in the oxide layer nearer to the outer, the middle, and the inner (adjacent to the solder matrix) was found to be 1:2, 2:3 and 1:1, respectively. The result was validated using XPS which gave Sn to O ratio of 1:2 at 5 nm depth of surface oxide. Originality/value - This is the first time FIB technology has been used to prepare TEM specimens for solder particles and TEM pictures shown of their surface oxide layer. Though requiring more care in sample preparation, the measurements by TEM and STEM are believed to be more direct and precise.
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| 3. |
- Zhang, L., et al.
(författare)
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Study on the adhesion strength of new nano-structured polymer-metal composite for thermal interface material (Nano-TIM) under different pressures
- 2011
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Ingår i: Proceedings - 12th International Conference on Electronic Packaging Technology and High Density Packaging, ICEPT-HDP 2011, Shanghai, 8-11 August 2011. - 9781457717680 ; , s. 426-429
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Konferensbidrag (refereegranskat)abstract
- With the continual increase in cooling demand for microprocessors, the microelectronics industry has been increasingly focused on the development of thermal solutions. Thermal Interface Material (TIM) plays a key role in reducing the thermal resistance of packaging and the thermal resistance between the electronic device and the external cooling components. Nano-TIM, a new type of thermal interface material, was developed to improve the heat dissipation of electronic devices. This paper describes work undertaken to research the reliability of Nano-TIM. Pull tests were used to investigate the shear strength of samples with Nano-TIM of different thicknesses coalesced between two PCBs with Sn coating made under different pressure. Scanning Electron Microscopy (SEM) analysis techniques were used to determine the morphology of the shear fracture section after pull tests and observe the structure of the cross section of Nano-TIM coalesced between two PCBs with Sn coating.
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