What is IC?
IC stands for the Integrated circuit.
The integrated circuit is a complete electronic circuit that entails both the active and passive components fabricated on an extremely tiny chip of silicon: Active components are tube and semiconductor type components such as FETs, transistors, SCR and passive components are resistors, capacitors, and inductors.
Journey of IC
The IC was devised in 1958. It, diametrically, commenced a modern age of electronics. It was first felt in the computer and digital field.
The germ of computers employed vacuum tubes. Vacuum tubes were replaced by the transistor. Since transistors had many advantages i.e. cheaper in cost, smaller in size, less power consumption, and reliable.
Third-generation of computers employed ICs. The use of ICs reduced computer size and increased computer reliability and speed.
An IC consists of quite small fabrication that can be only seen through a microscope.
Basically, IC chips and Discrete circuits (the circuit entails separately manufactured components, such as resistors, inductors, capacitors, diodes, transistors, etc.) employed the same manufacturing process but ICs fabricates all the components at a time.
Advantages of ICs
1. Extremely small size.
2. Remarkably lightweight.
3. Very less cost.
4. More reliable because of the elimination of solder.
5. Low power consumption due to the smaller size.
6. Increased operating speeds because of the absence of the parasitic capacitance effect.
7. Rich market availability.
8. Greater ability to operate at extreme temperatures.
1. Individual component(s) cannot be removed. Therefore, the whole chip should get replaced if a component fails.
2. Limited power rating, it cannot be manufactured for over 10W.
3. Inductors and transformers cannot be fabricated on a chip. Namely, its connection participates externally.
4. Apprehensive handling as these cannot withstand rough handling or excessive heat.
5. Exterior connection of capacitor, it's neither convenient nor economical to fabricate capacitor exceeding 30pf capacitance inside the chip. Thus, higher capacitance is connected exterior to chip.
6. High-grade PNP assembly not acceptable.
7. The low-temperature coefficient is difficult to attain.
8. Difficult to fabricate an IC with low noise.
9. An oversized value of saturation resistance of the transistor.
10. Voltage dependence of resistors and capacitors.
However, the benefits of ICs over the discrete circuit far outweigh their limitations.
Based on the fabrication technique used, ICs can be divided into the following three types.
Types of ICs
1. Monolithic ICs
Mono= single
Lithos= stone
Thus, the circuit is build of one stone or single crystal on which all the components are connected. This technology is helpful for ICs production at large scale and low cost.
It is used as AM receivers, amplifiers, voltage regulators, TV, and computer circuits.
However, Monolithic ICs have some limitations:
1. Low power ratings. It, typically, has the utmost power consumption of 1W.
2. Not rich isolation among components.
3. No possibility for the fabrication of inductors.
4. Only a little range of passive components can be used.
5. Lack of flexibility in circuit design.
2. Thin and Thick Film ICs.
These devices are usually larger than monolithic ICs. Such ICs are generally employed when much power required than Monolithic ICs. In this, active components like transistors and diodes are connected as discrete components.
The discrepancy between Thin and Thick Film ICs isn't about their size but the method of deposition of the film. Both have similar appearances, properties, and general characteristics.
Thin-film ICs
Here fabrication is done by depositing conductive films on the surface of a glass or ceramic base. It embodies various components by means of depositing films. In order to produce capacitance, films are sandwiched of insulating oxide between two conducting films. Inductors pertain to the spiral formation of films. While transistors and diodes can also be produced by thin-film technology; but tiny discrete components are connected into the circuit.
There are few methods for producing thin films, vacuum evaporation within which vaporized material is deposited on a substrate contained in a vacuum. Furthermore, one process called cathode sputtering, atoms from a cathode made from the specified film material. These are deposited on a substrate located between a cathode and an anode.
Thick-film ICs
In thick-film ICs type, silk-screen printing used that establishes the desired circuit pattern on a ceramic substrate. The screen is endowed with many features like stainless steel, conductive, resistive, or dielectric properties. These properties are possible because of inks and stainless steel uses within the thick-film ICs. It also fired at high temperature in a furnace to fuse the films to the substrate. Active and passive components arrangement is the same as Thin-film ICs do. It, moreover, connects active components as tiny discrete components.
ICs produced by thick and thin technologies have advantages of a wider range, better tolerance, and isolation among components, greater flexibility in circuit design with high-frequency performance than monolithic ICs.
However, such ICs have some drawbacks of larger size, high cost, and incapability of fabrication of active components.
3. Hybrid or multi-chip ICs
As the name infers, the circuit is fabricated by interconnecting a number of individual chips. These chips are widely used for high power audio-amplifier from 5W to more than 50W range.
It is basically known on account of its better performance than monolithic like Thin and Thick Film ICs. It's economical for less production and often used as a prototype for monolithic ICs. It can even be classified as bipolar active devices (BJTs) and unipolar active devices (FETs) as per their uses.
With each passing year, technology is advancing ICs frontiers. Now, components fabrication has been increased with a batter processing speed.
Whereby, ICs are classified as per the 'number of gates or circuits & components as per chip'.
1. Small Scale Integration (SSI): The area of SSI chip is 1sq. mm. It can contain less than 10 components and between 3 to 30 circuits per chip. SSI can be classified as both the linear and digital ICs.
2.Medium Scale Integration (MSI): It can contain 10 to 100 components and between 30 to 300 circuits per chip.
3. Large Scale Integration (LSI): The area of the LSI chip is 1sq. cm. It can contain 100 to 1000 components and between 300 to 3000 circuits per chip. LSI can be classified as both the linear and digital ICs as per the mode of operation. It can also be classified as analog ICs because their inputs and outputs can take on a continuous range of values and outputs are generally proportional to the inputs. This IC is much less used than digital ICs. LSI is vastly employed in the military, industrial, and consumer applications as different reasonably amplifiers where an Operational amplifier is a remarkable form of LSI.
4. Very Large Scale Integration (VLSI): It can contain more than 1000 components and more than 3000 circuits per chip.
Digital ICs are generally easy to replace with lower cost and better reliability. Approx. 80% of the IC market has been overshadowed by digital ICs. Digital ICs are widely employed in computers and logic circuits. Digital ICs like logic gates, flip-flops, clock chips, calculator chips, counter, memory chips, and microprocessors.
I hope the blog "What is IC?" helped you to know about IC and its type.
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