MICROELECTRONICS

Cards (102)

  • Microelectronics
    Field of electronics engineering that deals with the design and fabrication of small electronic devices such as microprocessors, using techniques such as photolithography.
  • The small electronic devices are typically fabricated using microelectromechanical systems (MEMS) or microelectronic mechanical systems (MEMS).
  • Microelectromechanical systems (MEMS)

    These are small structures that can be integrated into electronic circuits.
  • Semiconductor materials
    These are the building blocks of microelectronics.
  • One key aspect of microelectronics is the use of semiconductor materials, such as silicon, to create the small structures and devices that are needed.
  • Benefits of Microelectronics
    1. Miniaturization
    2. Power Efficiency
    3. Advancements in computing
    4. Innovation across industries
    5. Economic impact
  • Vacuum Tubes
    Controls flow of electric current; used in transistors for amplifiers
  • 1 integrated circuit = m/billions of transistors
  • Transistors
    Three terminal device; usually for amplifiers.
  • Semiconductor Diode
    Two terminal device
  • Vacuum tubes uses metal chassis which weighs 40 to 50 pounds.
  • Vacuum tubes required a warm-up time from 1 to 2 minutes, it generated a lot of heat.
  • Vacuum tubes required hefty power supply voltages of 300 volts dc and more.
  • A circuit could be designed either as a complete system or as a functional part of a larger system.
  • In complex systems, such as radar, many separate circuits were needed to accomplish the desired tasks.
  • Multiple function tubes, such as dual diodes, dual triodes, tetrodes, and others helped considerably to reduce the size of circuits.
  • Weight, heat, and power consumption continued to be problems that plagued designers.
  • Point-to-point wiring
    A method of wiring components which is another major problem with vacuum-tube circuits.
  • Point-to-point wiring
    This wiring looks like a rat's nest and it often caused unwanted interactions between components.
  • Point-to-point wiring
    Usually repaired with general purpose test equipment and common hand tools.
  • EINAC
    A completely electronic computer built in 1945 which contained 18,000 tubes. It often required a full day just to locate and replace faulty tubes.
  • Cathode-ray tubes
    Used in radar, television, and oscilloscopes do not, as yet, have solid-state counterparts.
  • MODULAR PACKAGING
    One concept that eased the technician's job because instead of building a system on one large chassis, it was built of modules or blocks.
  • Vacuum tubes
    Basis for electronic technology for many years and some are still with us.
  • The emphasis of technology is in the field of microelectronics.
  • Applications of Microelectronics
    1. Integrated Circuits
    2. Microprocessors
    3. Memory Devices
    4. Microsensors and Actuators
    5. Microcontrollers
  • Solid-State Devices
    Device which electrically flows through solid semiconductor crystals rather than vacuum tubes
  • Solid-state chassis
    Considerably smaller and lighter than the older tube chassis.
  • Printed Circuit Board (PCB)

    One of the most significant developments in circuit packaging.
  • Printed Circuit Board (PCB)

    Usually an epoxy board on which the circuit leads have been added by the photoetching process.
  • Photoetching process
    This process is similar to photography in that copper-clad boards are exposed to controlled light in the desired circuit pattern and then etched to remove the unwanted copper.
  • Photoetching process leaves copper strips (LANDS) that are used to connect the components.
  • Printed Circuit Boards eliminate both the heavy, metal chassis, and the point-to-point wiring.
  • Vacuum tubes are easily removed for testing or replacements while PCB components are soldered into place and are not as easily removed.
  • Normally, each PCB circuit contains a single circuit or a subassembly of a system.
  • Cabling Harnesses
    Groups of wiring or ribbons of wiring.
  • All printed circuit boards within the system are routinely interconnected through cabling harnesses.
  • Cordwood Module
    Another mounting form that has been used to increase the number of components in a given space.
  • In cordwood module, components are placed perpendicular to the end plates.
  • The components in a cordwood module are closely packed, appearing to be stacked like a cordwood for a fireplace.