The advent of Integrated Circuit (IC) is a major breakthrough in the field of electronics industry. The field of the electronics moved towards microelectronics with the reduction in the size of the components drastically with further development of technology over the years. Integrated circuits have seen various trends and many developments. Initially, they were manufactures as monolithic IC, but with the advancement of technology, hybrid ICs have come into picture. Each has certain benefits to use.
Monolithic IC
The word ‘Monolithic’ is of Latin origin which literally means ‘One Stone’. In early stage, the IC was a monolithic unit. Such ICs were the first integrated circuits manufactured. A number of electronic circuits are formed on a single silicon chip. A number of transistors and diodes are fabricated on a single silicon chip with the help of diffusion process. In this process, thousands of millions of transistors are formed on the single chip, preferably silicon with the diffusion of impurities on the chip. These components are connected to each other with the help of metallization process in order to make the desired electronic circuit. Different isolation techniques like PN junction, beam-lead and dielectric are used to isolate the components on a chip. The process results in creation of very small and compact circuits.
The process of manufacturing the monolithic IC is cheap and mass production can happen. They also exhibit good thermal stability due to close placement of components. They use mainly photolithography and planar technology.
However, this technology is faced with the shortcoming that it cannot be used to manufacture large value capacitors, inductors and resistors on the chip. If required, these components can be used separately with the chip.
Hybrid ICs
As the name suggests, a hyrind IC is a combination of monolithic IC and different components and circuits on a common substrate that acts as chassis. It comes as benefit over monolithic IC as a fact that this IC contains components like large value resistors, capacitors and inductors, which cannot be formed by the monolithic process.
The technology used is thin film or thick film technology based on the approach used to manufacture the components on a silicon chip. In thin film technology, the evaporation of a suitable impurity on the substrate surface leads to the formation of resistors, capacitors and transistors, whereas in thick film technology, silk screening method is used to create resistors and capacitors. The components can be planar in region and the adjustment in the values of the components can be done with the help of laser trimming and fine laser trimming.
It is not advisable to go for mass scale production of hybrid IC. These can be manufactured to some degree of three dimensions.