A hybrid integrated circuit has more than one chip in the package. The chips may be monolithic integrated circuits and separate or "discrete" devices such as transistor or diode chips. There can also be discrete passive components such as capacitor and resistor chips. The chips are usually mounted on an insulating ceramic substrate, usually alumina (Al2O3), and are interconnected by a thin-film or thick-film conductor pattern that has been deposited on the ceramic substrate. Thin-film patterns are deposited by vacuum evaporation techniques and are usually about 1 micrometer in thickness, whereas thick-film patterns are pastes that are printed on the substrate through a screen and usually range in thickness from 10 to 30 micrometers.
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