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What problems were evident about military electronic systems during World War II?
- Size
- Weight
- Power consumption.
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What discovery opened the door to solid-state electronics?
The transistor and solid-state diode.
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What is microelectronics?
Technology of electronic systems made of extremely small electronic parts or elements.
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What discovery proved to be the foundation for the development of the vacuum tube?
The Edison Effect.
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Name the components which greatly increase the weight of vacuum-tube circuitry.
- Transformers
- Capacitors
- Resistors.
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What are the disadvantages of point-to-point wiring?
"Rat's nest" appearance and unwanted interaction, such as capacitive and inductive effects.
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What is a major advantage of modular construction?
Rapid repair of systems and improved efficiency.
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When designing vacuum-tube circuits, you must take what characteristics of tubes into consideration?
Differences in performance of tubes of the same type.
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List the major advantages of printed circuit boards.
Eliminate heavy chassis and point-to-point wiring.
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What is the major disadvantage of printed circuit boards?
Components soldered in place.
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The ability to place more components in a given space is an advantage of the _______.
Cordwood module.
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Define integrated circuit.
Elements inseparably associated and formed in or on a single substrate.
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What are the three major types of integrated circuits?
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How do monolithic ICs differ from film ICs?
Monolithic ICs contain active and passive elements. Film ICs contain only passive elements.
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What is a hybrid IC?
Combination of monolithic ICs and film components.
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How many logic gates could be contained in lsi?
1,000 to 2,000.
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What are the basic steps in manufacturing an IC?
Circuit design, component placement, suitable substrate, and depositing proper materials on substrate.
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Computer-aided layout is used to prepare _______ devices.
Complex.
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What purpose do masks serve?
Control patterns of materials on substrates.
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What type of substrates are used for film and hybrid ICs?
Glass or ceramic.
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Describe the preparation of a silicon substrate.
Crystal is sliced into wafers. Then ground and polished to remove any surface defect.
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Name the two types of monolithic IC constructions.
- Diffusion
- Epitaxial growth.
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How do the two types of monolithic IC construction differ? (Diffusion and Epitaxial growth)
Diffusion penetrates substrate; epitaxial does not.
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What is isolation?
Electrical separation of elements.
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What methods are used to deposit thin-film components on a substrate?
Evaporation and cathode sputtering.
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How are thick-film components produced?
Screening.
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What is a hybrid IC?
Combination of monolithic and film elements.
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What is the primary advantage of hybrid circuits?
Circuit flexibility.
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What is the purpose of the IC package?
Protect the IC from damage; make handling easier.
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What are the three most common types of packages?
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What two methods of manufacture are being used to eliminate bonding wires?
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On DIP and flat-pack ICs viewed from the top, pin 1 is located on which side of the reference mark?
Left.
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DIP and flat-pack pins are numbered consecutively in what direction?
Counterclockwise.
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Viewed from the bottom, TO-5 pins are coumted on what direction?
Clockwise.
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The numbers and letters on ICs and schematics serve what purpose?
Identify the type of IC.
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Standardized terms improve what action between individuals?
Communications.
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Microcircuit refers to any component containing what types of elements?
Integrated circuits.
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Components made up exclusively of discrete elements are classified as what type of electronics?
Miniature.
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Resistors, capacitors, transistors, and the like, are what level of packaging?
Level 0.
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Modules or submodules attached to a mother board are what packaging level?
Level I.
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What is the packaging level of a pcb?
Level II.
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What are the three most common methods of interconnections?
- Conventional printed circuit boards
- Multilayer printed circuit boards
- Modular assemblies.
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Name the three methods of interconnecting components in multilayer printed circuit boards.
- Clearance hole
- Plated-through hole
- Layer build-up.
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What is one of the major disadvantages of multilayer printed circuit boards?
Difficulty of repair of internal connections.
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What was the earliest form of micromodule?
Cordwood modules.
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In what publication are environmental requirements for equipment defined?
Procurement specifications.
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In what publication would you find guidelines for performance of military electronic parts?
Military Standards.
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Who is responsible for meeting environmental and electrical requirements of a system?
Equipment designers (planners).
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What methods are used to prevent unwanted component interaction?
- Ground planes
- Shielding
- Component placement.
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