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This paper proposes the robust H2 controller with constraints for the active suspension using the half car model. The purpose of this study is to improve the ride comfort with satisfying the structural constraints. According to International Organization for Standardization 2631, there exist the uncomfortable frequency bands of the human body. The uncomfortable frequency bands are 4–8[Hz] for the...
We have studied a thermo-compression bonding method for high density interconnections. Fluxes are commonly used in conventional solder bonding. However, flux applications have several issues such as the void generation in solder and the flux residue remaining between bumps. These could degrade their reliabilities seriously when the bump pitch becomes small since these features do not scale to bump-pitch...
3D organic packages with three-die stack were evaluated by finite element analyses and thermal cycle tests. The thermal cycle tests with different silicon thickness configurations were performed. The die-stack test vehicles with thin top die (150μm) did not show any failures during the 2000 cycles of thermal cycle tests. However, failures were detected for the test vehicles with thick top dies (400μm)...
In ASET (Association of Super Advanced Electronics Technologies), the thermal resistances of three-dimensional (3D) chip stacks have been measured by using 3D stacked thermal test chips which are implemented with PN junction diodes for temperature sensors and diffused resistors for heating. The equivalent thermal conductivity of interconnection between stacked chips (SnAg + Cu post) and that of TSV...
The thermal resistance of a three-dimensional (3D) chip stack is evaluated, based on the measured thermal resistances of 3D stacked thermal test chips which are implemented with PN junction diodes for temperature sensors and diffused resistors for heating. It is discussed how much heat generation of a 3D chip stack is permitted, when a conventional cooling from the top of a 3D chip stack is assumed...
Packaging of 3D die stacks on organic laminates is a low-cost approach to achieve devices with high density I/O and short wiring delays. However, the large mismatch in coefficients of thermal expansion between components in the package causes deformation and high stress in the constituting elements. The components such as thin dies, metal through silicon vias, fine-pitch interconnections are susceptible...
In this study, the required heat transfer coefficient of heat sink is quantitatively shown by steady heat conduction simulation. Maximum principal stress of silicon and equivalent stress of the TSV are obtained from thermal stress simulation.
The relation between maximum temperature in Si chip and varied heat transfer coefficients of heat sink is shown in Fig. 5. Maximum temperature for device operation was assumed to be 85 °C. Heat transfer coefficient of heat sink at device operation is estimated to be 4.5W/m2K by quadratic approximation of least square method. Maximum temperature of 3D SiP was almost 85 °C and uniform temperature distribution.
For the thermal management of three-dimensional (3D) chip stack, its thermal resistance needs to be clearly understood. In this study, 3D stacked test chips are fabricated, which are implemented with PN junction diodes for temperature sensors and diffused resistors for heating. At SemiTherm2011, the equivalent thermal conductivity of the interconnection, including BEOL (Back-End-Of-the-Line, wiring...
Numerical methods such as the finite element method (FEM) have been used to evaluate the reliability of electronic packages. However, it is difficult to assure the accuracy of numerical analyses of electronic packages, which require nonlinear analyses. In this study, we evaluated the thermal strain of a test chip for three-dimensional stacked integrated circuits (3D SIC) with both measurement and...
The thermo-mechanical reliability of stacked die structures is a critical issue in 3D packaging. The assessment of the stress and the warpage of silicon dies in 3D stacked structures become important in achieving low-stress and low-warpage 3D packaging. However the parametric analyses of thermal stress and die-warpage by rigorous finite element analysis can be time consuming for 3D systems, since...
TSV (Through Silicon Via) is one of the key elements for building 3D integrated silicon devices with high bandwidth interconnections. In this paper, we propose a diagnostic method for TSV defects by using X-ray projection microscopy. By optimizing the image contrast of the X-ray projection micrographs in reference to its X-ray intensity histogram, we could obtain the small defect features in TSVs...
In the late 1990's, the technology that is stacked multiple silicon chips on the package was developed [1]. Then SiP (System in Package) constructed with CPU and memory into a package is appeared. Recently, downsizing and high-performing of semiconductor packages have been studied. In conventional SiP, several semiconductor chips had been arranged in a plate [2–6]. Therefore, it is difficult to correspond...
Recently, high density 3D packaging technology has been developed to reduce the size and improve the performance of semiconductor devices [1–10]. Through silicon vias (TSV) technique enabled downsizing of electronic devices and faster signal communication between semiconductor chips. The delay time of signal, which depended on circuit length, was reduced by direct communication with TSV as compared...
To propose an appropriate cooling solution for a three-dimensional (3D) chip stack at the design phase, it is necessary to estimate the total thermal resistance of a 3D chip stack. The interconnection between stacked chips is considered as one of the thermal resistance bottleneck of a 3D chip stack, but it is not experimentally clear yet. We have previously measured the thermal conductivity of SnAg...
When optical input/output is the essential signal path from one CPU, the aggregate optical bandwidth will exceed 10 Tbps, which requires 500 optical channels at 20 Gbps. Since the CPU is mounted on a CPU carrier, the carrier has to have attachment points at the interface of the carrier. Although one can use the side walls to connect to optical cables with a large number of optical channels, 10 or...
Three-dimensional (3D) chip stacks are receiving more attention for system performance enhancements. However, because of the higher circuit density, the cooling of 3D chip stacks gets more challenging. In conventional cooling methods, a heat sink or a micro-channel cooler is located at the top of the chip to dissipate the generated heat in a chip. In this paper, possible cooling methods from the bottom...
We propose a new architecture of optical device integration on SLC carrier with capability of handling of the optical signals directly on MCM, or an optically enabled MCM, where VCSELs/PDs and the interface chips are placed closer to the main VLSI on a waveguide integrated SLC, while the optical connectors are at the periphery of the SLC carrier. This separated structure allows the highest number...
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