454,473 research outputs found

    High-Accuracy Molding to Expose Wires for System-in-Packages or Modules

    Get PDF
    In the field of semiconductor packaging, wire-shifting may occur during the molding process of manufacturing TMV (Through Mold Via) formed by wire bonding technology. The wire-shifting will cause deviations of the external electrical connection ends of the wires. This disclosure describes a high-accuracy molding method. More specifically, the method uses a restriction structure at the mold chase for the molding process, so as to control the wire-shifting. Further, the restriction structure also has a guiding effect on the wires, and therefore improving the success rate of the manufacturing because the wires are accommodated in the restriction structure

    InternalBlue - Bluetooth Binary Patching and Experimentation Framework

    Full text link
    Bluetooth is one of the most established technologies for short range digital wireless data transmission. With the advent of wearables and the Internet of Things (IoT), Bluetooth has again gained importance, which makes security research and protocol optimizations imperative. Surprisingly, there is a lack of openly available tools and experimental platforms to scrutinize Bluetooth. In particular, system aspects and close to hardware protocol layers are mostly uncovered. We reverse engineer multiple Broadcom Bluetooth chipsets that are widespread in off-the-shelf devices. Thus, we offer deep insights into the internal architecture of a popular commercial family of Bluetooth controllers used in smartphones, wearables, and IoT platforms. Reverse engineered functions can then be altered with our InternalBlue Python framework---outperforming evaluation kits, which are limited to documented and vendor-defined functions. The modified Bluetooth stack remains fully functional and high-performance. Hence, it provides a portable low-cost research platform. InternalBlue is a versatile framework and we demonstrate its abilities by implementing tests and demos for known Bluetooth vulnerabilities. Moreover, we discover a novel critical security issue affecting a large selection of Broadcom chipsets that allows executing code within the attacked Bluetooth firmware. We further show how to use our framework to fix bugs in chipsets out of vendor support and how to add new security features to Bluetooth firmware

    Deep trap, laser activated image converting system

    Get PDF
    Receiving an optical image on the surface of a photoconducting semiconductor is presented, storing the image in deep traps of the semiconductor, and later scanning the semiconductor with a laser beam to empty the deep traps, thereby producing a video signal. The semiconductor is illuminated with photons of energy greater than the band gap producing electron-hole pairs in the semiconductor which subsequently fill traps in energy from the band edges. When the laser beam of low energy photons excites the trapped electrons and holes out of the traps into the conduction and valence bands, a photoconductivity can be observed

    Overview of metal contacts technology on semiconductor

    Get PDF
    Over the past decades, researcher confronts new difficulties and breakthrough due to semiconductor innovation and these chances are evident in the endeavours that have been laid by semiconductor and optoelectronic devices. Semiconductor defined as a material which conducts electricity conditionally, hence making it useful in controlling for optoelectronic devices. It possesses intermediate conductivity, ranging between a conductor and an insulator. The superiority of metal-semiconductor plays a significant role in the performances of semiconductor devices and it is a powerful tool for improving performance in many areas of modern life

    Localization of superlattice electronic states and complex bulk band structures

    Get PDF
    The relative lineup of the band structures of the two constituents of a semiconductor superlattice can cause charge carriers to be confined. This occurs when the energy of a superlattice state is located in an allowed energy region of one of the constituents (the "well" semiconductor), but in the band gap of the other (the "barrier" semiconductor). A charge carrier will tend to be confined in the layers made from the semiconductor with the allowed region at that energy. It will have an exponentially decaying amplitude to be found in the semiconductor with a band gap at that energy

    Detoxification of water by semiconductor photocatalysis

    Get PDF
    An overview of the use of semiconductor photocatalysis for water purification is given. The basic principles of semiconductor photocatalysis are described along with the current understanding of the underlying reaction mechanism(s) and how it fits in with the major features of the observed Langmuir-Hinshelwood-type kinetics of pollutant destruction. These features are illustrated based on literature on the destruction of aqueous solutions of 4-chlorophenol as a pollutant, using titanium dioxide as the photocatalyst. The range of organic and inorganic pollutants that can be destroyed by semiconductor photocatalysis are reported and discussed. The basic considerations that need to be made when designing a reactor for semiconductor photocatalysis are considered. These include: the nature of the reactor glass, the type of illumination source, and the nature and type of semiconductor photocatalyst. The key basic photoreactor designs are reported and discussed, including external illumination, annular, and circular photoreactors. Actual designs that have been used for fixed and thin falling film semiconductor photocatalyst reactors are illustrated and their different features discussed. Basic non-concentrating and concentrating solar photoreactors for semiconductor photocatalysis are also reported. The design features of the major commercial photocatalytic reactor systems for water purification are reported and illustrated. Several case studies involving commercial photocatalytic reactors for water purification are reported. An attempt is made briefly to compare the efficacy of semiconductor photocatalysis for water purification with that of other, more popular and prevalent water purification processes. The future of semiconductor photocatalysis as a method of purifying water is considered

    Low defect, high purity crystalline layers grown by selective deposition

    Get PDF
    The purity and perfection of a semiconductor is improved by depositing a patterned mask of a material impervious to impurities of the semiconductor on a surface of a blank. When a layer of semiconductor is grown on the mask, the semiconductor will first grow from the surface portions exposed by the openings in the mask and will bridge the connecting portions of the mask to form a continuous layer having improved purity, since only the portions overlying the openings are exposed to defects and impurities

    Picosecond Mode-Locking And X-Band Modulation Of Semiconductor Lasers

    Get PDF
    Recent developments in two areas of high speed semiconductor lasers will be addressed: (1) passive mode-locking of a segmented-contact semiconductor laser with a reliable, controllable saturable absorber which produces stable picosecond optical pulses, and (2) realization of very high frequency (X-band) direct analog modulation of a semiconductor laser diode
    • …
    corecore