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A Zilog Z80 in a 44-pin QFP package (special case: LQFP).

A QFP or Quad Flat Package is a surface mount integrated circuit package with "gull wing" leads extending from each of the four sides.^[1] Socketing such packages is rare and through-hole mounting is not possible. Versions ranging from 32 to 304 pins with a pitch ranging from 0.4 to 1.0 mm are common. Other special variants include low profile QFP and thin QFP.^[2]

The QFP component package type became common in Europe and United States during the early nineties, even though it has been used in Japanese consumer electronics since the seventies. It is often mixed with hole mounted, and sometimes socketed, components on the same printed circuit board.

A package related to QFP is PLCC which is similar but has pins with larger pitch, 1.27 mm (or 1/20 inch), curved up underneath a thicker body to simplify socketing (soldering is also possible). It is commonly used for NOR Flash memories and other programmable components.

Limitations[link]

The quad flat-pack has connections only around the periphery of the package. To increase the number of pins, the spacing was decreased from 50 mil (thousandths of an inch) (as found on small outline packages) to 20 and later 12 mil. However, this close lead spacing made solder bridges more likely and put higher demands on the soldering process and alignment of parts during assembly.^[1] The later pin grid array and ball grid array packages, by allowing connections to be made over the area of the package and not just around the edges, allowed for higher pin counts with similar package sizes, and reduced the problems with close lead spacing.

Variants[link]

Other styles

A Cyrix Cx486SLC in Bumpered Quad Flat Package format.   A 304-pin QFP with exposed thermal pad. A 304-pin QFP with exposed thermal pad.   An 80-pin TQFP package.   Plastic quad flat pack   A 144 pin low profile LQFP IC

The basic form is a flat rectangular (often square) body with leads at four sides but with numerous variation in the design. These differ usually only in lead number, pitch, dimensions, and materials used (usually to improve thermal characteristics). A clear variation is Bumpered Quad Flat Package with extensions at the four corners to protect the leads against mechanical damage before the unit is soldered.

Heat sink Quad Flat Package, Heatsink Very-thin Quad Flat-pack No-leads (HVQFN) is a package with no component leads extending from the IC. Pads are spaced along the sides of the IC with an exposed DIE that can be used as ground. Spacing between pins can vary.

A thin quad flat pack (TQFP) provide the same benefits of the metric QFP, but are thinner. Regular QFP are 2.0 to 3.8 mm thick depending on size. TQFP packages range from 32 pins with a 0.8 mm lead pitch, in a package 5 mm by 5 mm by 1 mm thick, to 256 pins, 28 mm square, 1.4 mm thick and a lead pitch of 0.4 mm.^[2]

TQFPs help solve issues such as increasing board density, die shrink programs, thin end-product profile and portability. Lead counts range from 32 to 176. Body sizes range from 5 mm x 5 mm to 20  x 20 mm. Copper lead-frames are used in TQFPs. Lead pitches available for TQFPs are 0.4 mm, 0.5 mm, 0.65 mm, 0.8 mm, and 1.0mm. PQFP, or plastic quad flat pack, is a type of QFP, as is the thinner TQFP package. PQFP packages can vary in thickness from 2.0 mm to 3.8 mm. A Low-profile Quad Flat Package is a surface mount integrated circuit package format with component leads extending from each of the four sides. Pins are numbered counter-clockwise from the index dot. Spacing between pins can vary; common spacings are 0.4, 0.5, 0.65 and 0.80 mm intervals.

Some QFP packages have an Exposed Pad. The exposed pad is an extra pad underneath or on top of the QFP that may act as a ground connection and/or as a heat sink for the package. The pad is typically 10 or more mm², and with the pad soldered down onto the ground plane heat is passed into the PCB. This exposed pad also gives a solid ground connection. These type of QFP packages often have a -EP suffix (e.g. a LQFP-EP 64), or they have an odd number of leads, (e.g. a TQFP-101).

See also[link]

• Chip carrier
• Pin grid array An alternative integrated circuit pin arrangement design

References[link]

1. ^ ^{a b} William J. Greig Integrated circuit packaging, assembly and interconnections, Springer, 2007 ISBN 0-387-28153-3 pages 35-26
2. ^ ^{a b} Charles Cohn, Charles A. Harper (ed) Failure-free integrated circuit packages, McGraw-Hill, 2005 ISBN 0-07-143484-4 pages 22-28

External links[link]

• HVQFN Documentation at NXP Semiconductors
• More about HQVFN
• PQFP packaging information from Integrated Silicon Solution, Inc. (PDF)

Wikimedia Commons has media related to: Quad flat packages

Look up quad or quadri- in Wiktionary, the free dictionary.

Quad may refer to:

Architecture[link]

• Quadrangle in architecture, e.g., on a university campus
• Quad, a dormitory room or suite housing four residents
• Quad Cities, a region which includes the Iowa cities of Bettendorf and Davenport and the Illinois cities of Moline, East Moline, and Rock Island

Armaments[link]

• Quad indicates four guns in a single mounting

Beer[link]

• Quadrupel is a Belgian style ale of great strength with bolder flavor compared to its Dubbel and Tripel sister styles.

Games[link]

• Quad Damage, a Quake and Unreal Tournament power-up
• Quad, a type of combined robotic enemy in the Nintendo Gamecube game Metroid Prime 2
• Quad (more commonly Quads), four of a kind in poker
• Quad, a Harkonnen attack vehicle from the computer game Dune 2
• Quad cannon, an anti-air weapon in Command & Conquer: Generals

International trade[link]

• The Quadrilateral group of finance ministers

Music, theatre and film[link]

• Quad (play), by Samuel Beckett
• Quad (music), a musical project by Gary Ramon
• Quad (cinema), art house in New York City
• Quad Electroacoustics, a British manufacturer of electronic amplifiers, tuners and loudspeakers mainly for the high-end domestic market
• Quadraphonic, or four-channel sound
• Quadrophenia, a 1973 album by The Who
• Quad Toms, marching percussion instrument
• Quad, a film poster in the United Kingdom typically measuring 30 by 40 inches (76 × 102 cm)
• The Quads, the British new-wave band
• QuadCarbon, fictional corporation in movie Proof of Life
• John Callahan's Quads!, an animated series from Nelvana
• Quad, a unit of computer storage measurement in the fictional Star Trek universe
• Derby QUAD, an arts centre in Derby, England
• The Quad, a part of Hogwarts Castle (made only for films and games).

Universities[link]

Most major American universities, as well as many smaller colleges, have an open area of campus surrounded by buildings commonly known to the students as "The Quad". Some of these "quads" have been officially designated with formal names.

Politics[link]

• In the United Kingdom; the informal cabinet grouping of David Cameron, Nick Clegg, George Osborne, and Danny Alexander

Science and mathematics[link]

• Quadriceps, a group of muscles
• Quadruped, a creature or mechanism which moves on four legs
• Quad (energy), a unit of energy (short for quadrillion) defined as 10¹⁵ British thermal units (about 1.055 exajoule (EJ) or 1.055 × 10¹⁸ J)
• Quadrilateral, a four sided figure in plane geometry
• Quadratic, the second power in mathematics
• Quadrangle (geography), a 7.5-minute topographic map produced by the United States Geological Survey, covering in greater detail one quarter of the area of a 15-minute map
• Quadrilateralized Spherical Cube, a mapping scheme for data collected on a spherical surface, such as a planet
• QUaD, a telescope located at the South Pole that is designed to measure the cosmic microwave background radiation polarization
• Quadratic Formula, the equation used to solve quadratic equations

Society and religion[link]

• Quad, a derogatory term for a quadriplegic
• Quadrangle Club, one of the ten eating clubs at Princeton University
• BU Quad, student publication of Boston University started in 2009

Sports[link]

• Quad, a boat configuration in rowing that contains 4 people, with 2 oars each, and no coxswain
• Quad, a chairlift in skiing which carries four persons
• Quad (figure skating), a figure skating jump with four revolutions
• Quad skates, roller skates with two wheels on each of two axles
• Quad, A type of surfboard containing 4 fins
• Quad, (Wrestling) A Dual Meet consisting of 4 teams. Also called a Quadangular.
• Quad, an All-Terrain Vehicle (ATV) with four wheels.

Technology[link]

• Quad antenna, a directional antenna
• Quad-core, a multi-core processor with 4 cores
• Quadtree, a tree data structure typically used to partition a 2-dimensional space
• Quad precision, a number stored using 16 eight-bit bytes, which is four times the size of 4-byte single precision
• Quad Flat Package, a type of package for surface mounted integrated circuit
• Quad Electroacoustics, a British manufacturer of electronic amplifiers, tuners and loudspeakers mainly for the high-end domestic market
• Quad, an abbreviation for a type of videotape recorder, especially 2" Quadruplex videotape, where there are four record heads on a spinning drum which move perpendicular to the direction of tape travel
• Quad, telecommunication term referring to four conductors formation used to form two balanced pairs
  • Star quad, four conductors in square formation, in which opposite conductors are connected in parallel at both ends to form a single, magnetically-concentric balanced pair, in order to minimise magnetic induction
• Quadraphonic sound, or four-channel sound
• quad, abbreviation for Quadrupole ion trap
• Em quad, in typography, a space that is as wide as the height of the font
  • En quad, a space that is one half the width of an em quad
• QUAD (cipher), a stream cipher
• Quadruple precision floating-point format, a data type in computer programming.

Vehicles[link]

• Quadriga
• Quadruple combination fire apparatus that features a pump, tank, hose and a full complement of ground ladders
• Quad, a tandem bicycle with four seats
• Quad, a muscle car with a four-barrel carburetor
• Quad, the nickname of the Morris C8 artillery gun tractor
• Quad (rocket), an autonomous rocket by Armadillo Aerospace
• Quads refer to four exhaust pipes (usually grouped two on each end) of a vehicle
• Quad bikes, four-wheeled all-terrain vehicles.
• other term for a speeder, a motorized vehicle used for maintenance of ways on railroads

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