Microelectronics is the art and science of electronic circuits and systems realised from extremely small electronic components. The Hybrid Microcircuit is the physical realization of an electronic circuit from two or more discrete circuit elements, like integrated circuits, transistors, diodes, resistors, capacitors, transformers and conductors. These are usually mounted on an insulating substrate to produce circuit functions similar to but with advantages over monolithic integrated circuits. Thick Film Hybrid Microcircuits (TFHMC) are made with the substrate depositions designed and fabricated by screen printing; and then firing of layers of highly viscous pastes composed of noble metal powders, vitreous binders etc.

The Thick Film Hybrid Microcircuits would find application in the fields of Aeronautical, Defence, Medical, Space, Electronic Entertainment Devices, Research & Development, Information & Communication system.

Hybridization of the circuits will ensure reduction in cost as well as reliability of the product as compared to import substitutes. Easy access to technology source, Complete backup service are the added advantages of Thick Film Hybrid Microcircuits technology.

PROCESS

Fabrication of thick film hybrid microcircuits is done by the screen printing of conductive, dielectric and resistive pastes on to 96% alumina substrates. These pastes, when fired at temperatures in the range of 800⁰ to 1000⁰C, become an integral part of the substrate and form the basic structure of the hybrid microcircuit. Out of tolerance resistors can be trimmed to desired values upto 1% accuracy or more, by using air abrasive / laser technique. Functional trimming is utilised where circuit function is of prime importance compared to specific value of resistance and tolerance. Discrete components, both active and passive, are added to the substrate with the generated basic structure to complete the circuit, and finally hermetically sealed into customer desired packages.