| 61. |
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| 62. |
- Chen, Liu, 1973, et al.
(författare)
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Reliability Investigation for Encapsulated Isotropic Conductive Adhesives Flip Chip Interconnection
- 2006
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Ingår i: Journal of Electronic Packaging, Transactions of the ASME. - : ASME International. - 1528-9044 .- 1043-7398. ; 128:3, s. 177-183
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Tidskriftsartikel (refereegranskat)abstract
- Isotropic conductive adhesives (ICA) are gaining more and more application interests in electronic manufacturing, however, their failure mechanism is not been fully understood. In this paper we present reliability investigations on an encapsulated ICA flip chip interconnection. Experimental work included product lifetime measurement, cross section observation, and whole module warpage scanning. Results revealed that the chip-size effect on the ICA lifetime was obvious. A theoretical analysis was conducted with Finite Element Method (FEM) simulation. Viscoelastic models for adhesives and underfill materials were employed, and the comparison with an elastic model was made. Calculated equivalent stresses S eqv and shear stress σ xy fitted well with the experimental lifetime measurement, thus a lifetime relationship similar to the Coffin-Manson formula was established to predict the thermal fatigue life of an encapsulated ICA flip chip. Furthermore, the influences of underfill properties on the ICA reliability were discussed. Copyright © 2006 by ASME.
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| 63. |
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| 64. |
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| 65. |
- Chen, Si, 1981, et al.
(författare)
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A High Performance Ag Alloyed Nano-scale n-type Bi2Te3 Based Thermoelectric Material
- 2015
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Ingår i: Materials Today: Proceedings. - : Elsevier BV. - 2214-7853. ; 2:2, s. 610-619
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Konferensbidrag (refereegranskat)abstract
- A silver alloyed n-type bismuth telluride (Bi2Te3) thermoelectric (TE) bulk material with nano crystalline structure was studied and characterized in this paper. The Bi2Te3 nanopowders used in this study were first fabricated via a patented explosion based process. Then, the various concentrations of Ag nanoparticles (0-20 wt. %) were added into the Bi2Te3 nanopowders in order to increase the electrical conductivity. Combining the benefits of high electrical conductivity (1.51x10(5) S.m(-1)) and low thermal conductivity (0.441 W.m(-1).K-1), the dimensionless figure of merit (ZT value) of 1.48 for this n-type Bi2Te3 TE material is achieved at 300 K temperature.
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| 66. |
- Chen, S., et al.
(författare)
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A Reliability Study of Nanoparticles Reinforced Composite Lead-Free Solder
- 2010
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Ingår i: Materials Transactions. - 1347-5320 .- 1345-9678. ; 51:10, s. 1720-1726
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Tidskriftsartikel (refereegranskat)abstract
- This work looks at the development and investigation of a reinforced composite solder with low melting point The composite solder was prepared by adding Sn 3 0Ag 0 5Cu nanoparticles Into Sn 58BI solder paste 1 he Sn 3 0Ag 0 5Cu nanoparticles were manufactured using a self developed Consumable electrode Direct Current Arc (CDCA) technique The test FR 4 Printed Circuit Board (PCB) with Cu pad and Electroless Nickel Immersion Gold (ENIG) surface finish were fabricated and fifty SR1206 chip resistors were mounted on pads of test PCB with the reinforced composite solder paste by using conventional surface mount technology The differential scanning calorimetry (DSC) was used to analyze the constituent of the composite solder Joint after reflow A scanning electron microscope (SEM) transmission electron microscope (TEM) and optical microscope (OM) were employed in order to observe the morphology of nanoparticles the microstructure of reinforced composite solder Joint the crack initiation and propagation in solder Joint and the fracture mode after shear test The thermal cycling (TC) was carried out with a temperature range of 40 degrees C and 125 C The contract resistance of the solder Joint was measured during thermal cycling and the shear test of solder Joints was performed before and after 500 thermal cycles After the shear test all fracture surfaces were inspected to identify the fracture mode of the composite solder joint The results of the experiments detailed in this work indicate that the shear strength of the composite solder increased 2 times in comparison to Sn 58B(1) Meanwhile the thermomechanical fatigue (TMF) resistance of the composite solder with 1 mass% nanoparticles was 16 times stronger than Sn 58BI and 4 times stronger than Sn 3 0Ag 0 5Cu However the tendency of forming micro cracks between nanoparticles and solder matrix and the fracture within solder was increased for solder joints with more than 3 mass% nanoparticles after thermal cycling.
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| 67. |
- Chen, S., et al.
(författare)
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A solder joint structure with vertically aligned carbon nanofibres as reinforcements
- 2014
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Ingår i: Proceedings of the 5th Electronics System-Integration Technology Conference, ESTC 2014. - 9781479940264 ; , s. Art. no. 6962851-
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Konferensbidrag (refereegranskat)abstract
- In this paper, a solder joint structure was developed for the electronic packaging industry. Vertically aligned carbon nanofibres (VACNFs) were grown, transferred and used at the interface between Si/Au pads and Sn-3.0Ag-0.5Cu (SAC305) alloy as reinforcements in order to increase the solder joint thermal fatigue resistance. The transfer and assembly processes related to VACNFs were optimised and developed. The thermal cycling test results show that the thermal fatigue life of VACNF/SAC305 solder joints is 40% longer than that of pure SAC305. The dye and pry analysis and scanning electron microscopy observation prove that the VACNFs can effectively delay the crack propagation near the interface and consequently prolong the solder joint thermal fatigue life.
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| 68. |
- Chen, S., et al.
(författare)
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An overview of carbon nanotubes based interconnects for microelectronic packaging
- 2017
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Ingår i: 2017 IMAPS Nordic Conference on Microelectronics Packaging, NordPac 2017, Goteborg, Sweden, 18-20 June 2017. - 9781538630556 ; , s. 113-119
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Konferensbidrag (refereegranskat)abstract
- Owing to the great demand in more functions and miniaturization in microelectronic packaging, the dimensions of interconnects has decreased extremely, which has resulted in electrical, thermal, and mechanical reliability issues. To address these issues, carbon nanotube (CNT) has been selected as a promising alternative material for the interconnects in packaging due to its large current density, high thermal conductivity, great flexibility, and low coefficient of thermal expansion (CTE). In this paper, the development of CNTs based vertical interconnects was reviewed. However, the resistivity of CNTs based interconnects was much higher than that of copper interconnects. Thus, this review focused on the resistivity of CNTs-based interconnects in different fabrication process and pointed out what improves the resistivity. In the future, CNTs-Cu nanocomposite with unique properties could be the suitable material for bumps to reduce the resistivity of CNTs based bumps further.
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| 69. |
- Chen, S., et al.
(författare)
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Coffin-Mansson equation of Sn-4.0Ag-0.5Cu solder joint
- 2009
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Ingår i: Soldering and Surface Mount Technology. - : Emerald. - 1758-6836 .- 0954-0911. ; 21:2, s. 48-54
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this paper is to fit Coffin-Manson equation of Sn-4.0Ag-0.5Cu lead free solder joint by using results of solders joint reliability test and finite element analysis. Also to present a novel device for solder joint reliability test. Design/methodology/approach: Two-points bending test of Sn-4.0Ag-0.5Cu lead free solder joint was carried out at three deflection levels by using a special bending tester that can control displacement exactly by a cam system. The failure criterion was defined as resistance of solder joint getting 10 percent increase. The X-section was done for all failure samples to observe crack initiation and propagation in solder joint. Finite element analysis was presented with ANSYS for obtaining shear strain range, analyzing distribution of stress and strain and supporting experimental results. Findings: The experimental results indicate that the fatigue life decreased obviously with the displacement increased. By using optical microscope and SEM photographs, two kinds of failure mode were found in solder joint. The majority failure mode took place at the bottom corner of solder joint under the termination of resistor initially, and propagated into the solder matrix. Another failure mode was delamination. It appeared at the interface between the termination of resistor and its ceramic body. The distribution status of stress and strain in solder joint and the calculation results of shear strain range at different deflection levels were obtained from simulation result. The Coffin-Manson equation of Sn-4.0Ag-0.5Cu lead free solder joint was fitted by combining experimental data with result of finite element analysis. Originality/value: This paper presents Coffin-Manson equation of Sn-4.0Ag-0.5Cu solder joint with two-points bending test. An effective and economical device was designed and applied.
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| 70. |
- Chen, Shujing, et al.
(författare)
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Manufacturing Graphene-Encapsulated Copper Particles by Chemical Vapor Deposition in a Cold Wall Reactor
- 2019
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Ingår i: ChemistryOpen. - : Wiley. - 2191-1363. ; 8:1, s. 58-63
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Tidskriftsartikel (refereegranskat)abstract
- Functional fillers, such as Ag, are commonly employed for effectively improving the thermal or electrical conductivity in polymer composites. However, a disadvantage of such a strategy is that the cost and performance cannot be balanced simultaneously. Therefore, the drive to find a material with both a cost efficient fabrication process and excellent performance attracts intense research interest. In this work, inspired by the core-shell structure, we developed a facile manufacturing method to prepare graphene-encapsulated Cu nanoparticles (GCPs) through utilizing an improved chemical vapor deposition (CVD) system with a cold wall reactor. The obtained GCPs could retain their spherical shape and exhibited an outstanding thermal stability up to 179 degrees C. Owing to the superior thermal conductivity of graphene and excellent oxidation resistance of GCPs, the produced GCPs are practically used in a thermally conductive adhesive (TCA), which commonly consists of Ag as the functional filler. Measurement shows a substantial 74.6 % improvement by partial replacement of Ag with GCPs.
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