- Hybrid integrated circuit
A hybrid integrated circuit, HIC, hybrid microcircuit, or simply hybrid is a miniaturized electronic circuit constructed of individual devices, such as semiconductor devices (e.g.
transistor s anddiode s) and passive components (e.g.resistor s,inductor s,transformer s, andcapacitor s), bonded to a substrate orprinted circuit board (PCB). Hybrid circuits are often encapsulated inepoxy , as shown in the photo. A hybrid circuit serves as a component on a PCB in the same way as a monolithicintegrated circuit ; the difference between the two types of devices is in how they are constructed and manufactured. The advantage of hybrid circuits is that components which cannot be included in a monolithic IC can be used, e.g., capacitors of large value, wound components, crystals.Thick film technology is often used as the interconnecting medium for hybrid integrated circuits. The use of screen printed thick film interconnect provides advantages of versatility over thin film although feature sizes may be larger and deposited resistors wider in tolerance. Multi-layer thick film is a technique for further improvements in integration using a screen printed insulating dielectric to ensure connections between layers are made only where required. One key advantage for the circuit designer is complete freedom in the choice of resistor value in thick film technology. Planar resistors are also screen printed and included in the thick film interconnect design. Resistor pastes are available in decade values usually in value steps of 10 ohms, 100 ohms, 1000 ohms (1 kilohm), 10 kilohms, 100 kilohms and 1 Megohm. Adjacent decade values in this series may be carefully blended to provide an almost infinite variation of intermediate paste values. The final resistor value is determined by design and can be adjusted by
laser trimming . Once the hybrid circuit is fully populated with components, fine tuning prior to final test may be achieved by active laser trimming.Some modern hybrid circuit technologies, such as LTCC-substrate hybrids, allow for embedding of components within the layers of a multi-layer substrate in addition to components placed on the surface of the substrate. This technology produces a circuit that is, to some degree, three-dimensional.
In the early days of telephones separate modules containing
transformers andresistors were called hybrids orhybrid coil s; they have been replaced by semiconductorintegrated circuit s.In the early days of
transistors the term "hybrid circuit" was used to describe circuits with both transistors andvacuum tube s; e.g., anaudio amplifier with transistors used for voltage amplification followed by a vacuum tube power output stage, as suitable power transistors were not available. This usage, and the devices, are obsolete.ee also
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Multi-chip module
*MMIC
*Solid Logic Technology External links
* [http://www.maxtek.com/technologies4.html Technologies : Hybrids & Mixed Technology]
* [http://www.cmac.com/services/manufacture/substrates/Thick-filmHybrids.php C-MAC MicroTechnology thick-film hybrids]
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