The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Cu-Cu is a prefer choice of interconnects as it offered lower electrical resistance, no risk of shorting between the bump and higher reliability as compared to Cu-Solder Bump. However, Cu-Cu interconnect requests stringent condition such as Cu bump surface topography, flatness, uniformity of pillar array heights and clean bonding surface. From throughput point of view, Cu-Cu bonding is challenging...
We study the question of building regional covariance descriptors (RCDs) for vehicle detection from high-resolution satellite images. A unified way is proposed to build RCD features by constant convolutional kernels in the forms of 2-D masks. Two novel formulas are designed to construct different RCD types based upon one or two convolutional masks, obtaining ten novel RCD features by four simple constant...
Ultra-fine pitch (6μm) interconnects are essential for high-end application-products that demands high speed and high bandwidth inter-chip communication. Achieving Cu-Cu bonding with such a fine pitch is challenging since bond time is too long and bond interface gets easily oxidized. Throughput issue associated with long-bonding time is solved by using 2-step bonding procedure where first step is...
In this paper, we present an improved vision-based navigation method and proposed an improved feature matching method for improving the matching accuracy. In the matching process, we divide it into two steps, coarse and fine matching. During the coarse matching step, we adopt SURF feature detector for feature detection and Fast Library for Approximate Nearest Neighbors for feature matching, and then...
In order to amplify the effective field of vehicle navigation, and overcome the obstacles such as poor road condition and bad weather, the SINS (Strap-down Inertial Navigation System) /DVL (Doppler Velocity Log) /OD (Odometer) integrated navigation technology is proposed. PWCS theory and SVD (singular value decomposition) are used to analyze observability of this integrated navigation system. In the...
For ultra-fine pitch and high density Cu pillar low temperature bonding (200°C), the surface contact between substrate and Cu pillar array is the key. Therefore, the fabrication quality of copper bump array affects severely the bonding results. The qualitative factors include (1) Cu pillar array height uniformity, (2) free of copper oxide layer, (3) Cu material property (e.g. elastic modulus, grain...
Throughput issue is limiting the adoption of 3D IC stacking process although 3D IC has many advantages in shorter communication lines, lower electrical parasitic and lower package footprint. Local thermal compression bond on each chip stack incurs enormous process time if there is a need to have multi-chip stack and it will be further complicated with the enormous number of chip stack on one 12"...
A static divide-by-2 frequency divider based on InP/InGaAs DHBT technology is presented. On chip thin film resistor and capacitor were integrated. Two levels of interconnect were developed. Composite collector design and 0.5µm emitter width enable the static frequency divider operated at a frequency over 100GHz.
Three-dimensional multiple-input multiple-output (3D MIMO) is a promising technology for the future wireless communication systems, since antenna tilt angle can reduce the intercell interference. In this paper, we consider 3D MIMO downlink analysis for a multicell multiuser scenario. Zero-forcing (ZF) precoding technique is applied at BS with perfect channel state information of all users in its cell...
A wafer level under-fill (WLUF) process for ultra-fine Cu-Cu bonding is developed. Under-fill is applied as pre-applied under-fill then planarized the surface. The methodology used for surface planarization (bit grinding) and surface treatment (H2 plasma) are fond to be important in the surface preparation and activation. Underfill material needs to have sufficient hardness and adhesion to the wafer...
The mechanism of period-doubling bifurcation in voltage mode controlled flyback converter operating in discontinuous conduction mode (DCM) is studied according to the theorem of period-doubling bifurcation, a one-dimensional discrete iterative map of the system, in which the primary side magnetizing inductor current of a transformer and the equivalent series resistance (ESR) of the capacitor is considered,...
At present, the joint utilization of the elevation factor in three-dimension (3D) channel model and antenna tilt angle in 3D base station is rarely investigated. In this paper, we consider the uplink of a multicell multiuser multiple-input multiple-output (MU-MIMO) system with a 3D base station exploiting variable antenna tilt angles. To illustrate clearly, we model a tall building with several floors...
Zero velocity update (ZUPT) is an important error control method for strap-down inertial navigation system (SINS). Conic fitting as a frequently-used ZUPT method is simple and effective, but makes low use of the velocity samples gained during the stops of SINS, and requires SINS to stop frequently. In order to solve these problems, a new ZUPT method based on support vector machine (SVM) regression...
Endpoint detection (EPD) is a critical control functionality for many etch processes, especially for deep silicon etches [1] that terminate on an underlayer. Where this device structure is employed, it is vital that the point at which the etch process reaches the underlayer is detected as promptly as possible. This allows for proper management of the overetch to clear all features to the underlayer...
A low temperature <200°C Cu-Cu bonding process is developed for 3D IC stacking application. To prepare and activate good copper surface, three planarization processes and two surface treatment methods are studied in details and compared. Best surface treatment method is identified. It is found that good Cu-Cu direct bonding with high shear strength is achieved by the developed process and verified...
It is difficult to get satisfactory customer churn prediction effect for the traditional model, because the class distribution of customer data is often imbalanced, and the available data in target task is little. This paper combines the transfer learning with the ensemble learning, and proposes a feature selection based transfer ensemble model (FSTE). It utilizes the customer data in both the related...
In this paper, to achieve the real-time joystick control of redundant manipulators, two schemes are proposed and investigated: one scheme is a cosine-based position-to-velocity mapping, which maps the position of the joystick in the motion range to the velocity of the robot end-effector for the real-time end-effector velocity generation; and the other is a real-time joystick-controlled motion planning...
An IMC based low temperature solder <200 °C with AuInSn composition is developed for 3D IC stacking application. Thermodynamic and mechanical simulations are conducted to study the phase change during the melting temperature and the stress due to the thin solder material. A three layer stack bonding with the developed solder has been characterized after bonding and reliability test. It is found...
A novel and practical multi-loop control strategy for photovoltaic (PV) inverters is presented. In which the double close-loop control structure of digital PID voltage and current instantaneous value is adopted based on the cross feedback decoupling control and load current feed-forward control. In addition, in order to improve accuracy of output voltage, a close loop control structure of the output...
In this paper, our issue is to minimize the number of repeaters while ensuring the full communications among certain number of people at the same time in a given region. Based on the different assumed conditions, we construct an Area Coverage Model (Model I) and a path model (Model II) for the minimum number of repeaters to cover the area or the path. After constructing these two basic models, we...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.