Hybrid circuit
Encyclopedia
Transistor
A transistor is a semiconductor device used to amplify and switch electronic signals and power. It is composed of a semiconductor material with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current...
s and diode
Diode
In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
s) and passive components (e.g. resistor
Resistor
A linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...
s, inductor
Inductor
An inductor is a passive two-terminal electrical component used to store energy in a magnetic field. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries...
s, transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
s, and capacitor
Capacitor
A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
s), bonded to a substrate or printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
(PCB). Hybrid circuits are often encapsulated in epoxy
Epoxy
Epoxy, also known as polyepoxide, is a thermosetting polymer formed from reaction of an epoxide "resin" with polyamine "hardener". Epoxy has a wide range of applications, including fiber-reinforced plastic materials and general purpose adhesives....
, as shown in the photo. A hybrid circuit serves as a component on a PCB in the same way as a monolithic integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
; 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
Thick film technology
Thick film technology is used to produce electronic devices such as surface mount devices, hybrid integrated circuits and sensors.Thick film circuits are widely used, in automotive industry, both in sensors ex...
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. The composition and dimensions of resistors can be selected to provide desired values. The final resistor value is determined by design and can be adjusted by laser trimming
Laser trimming
Laser trimming is the manufacturing process of using a laser to adjust the operating parameters of an electronic circuit.One of the most common applications uses a laser to burn away small portions of resistors, raising their resistance value...
. 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
Low temperature co-fired ceramic
Low temperature co-fired ceramic devices are monolithic, ceramic microelectronic devices. In this context ‘co-fired ceramic’ means that the ceramic support structure and any conductive, resistive, and dielectric materials are fired in a kiln at the same time, and ‘Low temperature’ means that the...
-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
Three-dimensional space
Three-dimensional space is a geometric 3-parameters model of the physical universe in which we live. These three dimensions are commonly called length, width, and depth , although any three directions can be chosen, provided that they do not lie in the same plane.In physics and mathematics, a...
.
Other electronic hybrids
In the early days of telephones, separate modules containing transformers and resistors were called hybrids or hybrid coilHybrid coil
A hybrid coil is a transformer that has three windings, and which is designed to be configured as a circuit having four branches, that are conjugate in pairs....
s; they have been replaced by semiconductor integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...
s.
In the early days of transistors the term hybrid circuit was used to describe circuits with both transistors and vacuum tube
Vacuum tube
In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...
s; e.g., an audio amplifier
Audio amplifier
An audio amplifier is an electronic amplifier that amplifies low-power audio signals to a level suitable for driving loudspeakers and is the final stage in a typical audio playback chain.The preceding stages in such a chain are low power audio amplifiers which perform tasks like pre-amplification,...
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, however amplifiers that use a tube preamplifier stage coupled with a solid state output stage are still in production, and are called hybrid amplifiers in reference to this.
See also
- Multi-chip moduleMulti-Chip ModuleA multi-chip module is a specialized electronic package where multiple integrated circuits , semiconductor dies or other discrete components are packaged onto a unifying substrate, facilitating their use as a single component...
(MCM) - Monolithic microwave integrated circuitMonolithic Microwave Integrated CircuitA Monolithic Microwave Integrated Circuit, or MMIC , is a type of integrated circuit device that operates at microwave frequencies . These devices typically perform functions such as microwave mixing, power amplification, low noise amplification, and high frequency switching...
(MMIC) - Solid Logic TechnologySolid Logic TechnologySolid Logic Technology was IBM's method for packaging electronic circuitry introduced in 1964 with the IBM System/360 series and related machines. IBM chose to design custom hybrid circuits using discrete, flip chip-mounted, glass-encapsulated transistors and diodes, with silk screened resistors...
(SLT)