电子信息类专业语Unit 4 Microelectronics.ppt

　　When P-type and N-type regions are formed in same crystal, the semiconductor is known as a diode or rectifier. The boundary between the two regions is termed a junction. The P-region terminal is called the anode, whereas the N-region terminal is called the cathode. 　　Usually, when such semiconductors are used with signals, the semiconductors are called diodes or signal diodes. When the device is used for conversion of alternating current (ac) to direct current (dc), the semiconductor is called a rectifier. 　　Basic Two-junction or Bipolar Transistor 　　Like a diode, a transistor can be used to prevent (or limit) the flow of current in one direction, The prime use for a transistor, however, is to control the amount of current in a circuit. This is done by adding a second junction to the basic diode junction, discussed in the above section. For this reason, such transistors are called two-junction transistors or, possibly, bipolar transistors. The author prefers the former term but recognizes that the latter term is also in common use. Unit 4 Microelectronics Unit 4 Microelectronics Passage A Introduction to Microelectronics Passage B The Simple Atom, Conductors, Insulators and Semiconductors Passage C Diode and Transistor Passage A Introduction to Microelectronics 　　The exploring of space and the development of earth satellites has increased the importance of reducing the size and weight of electronic circuits. Also, even though electricity flows quite rapidly in computers the time delay of the signal in the interconnections between electronic components is an important consideration. If the interconnections are reduced in size, a computer can perform operations at a faster speed. 　　Microelectronics involves the miniaturization of regular electronic circuits. A complete electronic circuit, an operational amplifier for example, which contains large numbers of individual interconnected components, such as diodes resistors, transistors, e