Classification, Characteristics and System of Symbols of the Main Types of Integrated Circuits
The rapid development of microelectronics and the increasing complexity of radioelectronic equipment led to the need to improve and create new microelectronic products with a large number of elements.
Integrated circuits (ICs) – microelectronic products with signal processing and (or) information accumulation function that have high density of structurally inseparable and electrically connected elements, components and crystals, which are considered indivisible by testing, acceptance, delivery and operation requirements, have emerged.
Advantages of ICs are: small size, weight and power consumption, high reliability and performance. Component of IC – structurally inseparable part of IC which performs function of one of radio elements (for example, diode, transistor, resistor, capacitor) and by requirements to testing, acceptance, delivery and operation cannot be considered as independent product, so it cannot be tested, packaged and exploited.
Component of IC – a part of IC which implements the function of one of the radio elements and with respect to the requirements to testing, acceptance, delivery and operation can be distinguished as an independent product. Components are manufactured separately and installed in the chip during assembly operations. Simple components include caseless diodes, transistors, capacitors, resistors, small inductors and transformers and the like.
Complex components are case-less ICs, functional microcircuits, etc. Basic IC is a structurally separated part of a semiconductor wafer with a specific set of formed elements, electrically connected and (or) not connected to each other, which is used to create ICs by making inter-element connections.
Various criteria can be used to classify ICs: the degree of integration, the physical principle of the active elements, the function performed, performance, power consumption, applicability in hardware, etc. According to the degree of integration integrated circuits are divided into types: simple (no more than 10 elements) medium (from 10 to 100 elements); large (LSI) (from 100 to 1000 elements; ultra-large (VLSI) – more than 1000 elements. By nature of functions which they carry out: digital microcircuits (triggers, encoders, comparators) analog microcircuits (amplifiers, signal generators). But the most common is the classification on constructive and technological features, since the name of the chip contains general information about its design and manufacturing technology.
Semiconductor integrated circuit is an IC, all the elements and inter-element connections of which are made in the volume or on the surface of the semiconductor. Semiconductor integrated circuit is most commonly represented by a silicon crystal, in the surface layer of which semiconductor technology methods are used to form regions which are equivalent to the elements of an electrical circuit, and the connections between them. A film integrated circuit is an IC, all of whose elements and interconnections are in the form of films. Film integrated circuits have a dielectric substrate (board) (glass, ceramics, etc.).
The substrates are dielectric plates with a thickness of 0.5-1.0 mm, carefully ground and polished. A hybrid integrated circuit is an IC in which the passive elements are film and the active elements are discrete. Discrete elements are miniature, most often frameless diodes and transistors, which are independent elements that are glued (soldered) in appropriate places to the substrate and connected by thin conductors to the film circuit elements. Hybrid ICs are often used as parts of high-frequency amplifier stages. A large IC (LIC) is a chip containing more than 1,000 elements and/or components for digital ICs and more than 500 for analog ICs. Multilayer structures are used in VICs with multiple liners that are arranged parallel to each other in multiple layers. Such a system of interconnecting elements is called a multilayer or multilayer divide.
Super large IC (VLSI) – contains more than 100 thousand elements and (or) components for digital ICs with irregular structure and more than 10 thousand – for analog ICs. Digital ICs with regular structure of construction include circuits of memory devices. Large and supersized ICs are complex microcircuits, in which blocks or even entire systems are implemented. For these reasons, they are not widely versatile and are intended mainly for specific types of equipment.