A QFP or Quad Flat Package is a surface mount

Surface-mount technology

Surface mount technology is a method for constructing electronic circuits in which the components are mounted directly onto the surface of printed circuit boards . An electronic device so made is called a surface mount device...

 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...

 package with leads extending from each of the four sides. Socketing such packages is rare and 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 LQFP

LQFP

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....

 (Low profile QFP) and TQFP

TQFP

A thin quad flat pack is a type of surface-mounted package. TQFPs provide the same benefits of the metric QFP, but are thinner and have a standard lead-frame footprint ....

 (Thin QFP).

The QFP component package type became common in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 and US during the early nineties, even though it has been used in Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese consumer electronics

Consumer electronics

Consumer electronics are electronic equipment intended for everyday use, most often in entertainment, communications and office productivity. Radio broadcasting in the early 20th century brought the first major consumer product, the broadcast receiver...

 since the seventies. It is often mixed with hole mounted, and sometimes socketed

Jack (connector)

In electronics and electrical assemblies, the term jack commonly refers to a surface-mounted connector, often, but not always, with the female electrical contact or socket, and is the "more fixed" connector of a connector pair...

, components on the same 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...

.

A package related to QFP is PLCC

Plastic leaded chip carrier

A plastic leaded chip carrier is a chip carrier with a equiangular plastic housing. It is a reduced cost evolution of the ceramic leadless chip carrier ....

 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

Nor

Nor may refer to:*In grammar, nor is a coordinating conjunction*Nór, the eponymous founder-king of Norway in Norse mythology*Nor , a character in the book in Wicked...

 Flash memories

Flash memory

Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...

 and other programmable components.

Variants

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.

• BQFP: Bumpered Quad Flat Package
• BQFPH: Bumpered Quad Flat Package with heat spreader
  Heat spreader
  A heat spreader is most often simply a copper plate, having high thermal conductivity. Functionally, it is a heat exchanger that moves heat between a heat source and a secondary heat exchanger whose surface area and geometry are more favorable. By definition, the heat is "spread out", such that...
  
  
• CQFP: Ceramic Quad Flat Package
• EQFP: Plastic Enhanced Quad Flat Package
• FQFP: Fine Pitch Quad Flat Package
• HQFP: Heat sinked Quad Flat Package
• LQFP
  LQFP
  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....
  
  : Low Profile Quad Flat Package
• MQFP: Metric Quad Flat Package
• PQFP
  PQFP
  PQFP, or plastic quad flat pack, is a type of IC packaging. PQFP is a special case of QFP, as is the thinner TQFP package.PQFP packages can vary in thickness from 2.0 mm to 3.8 mm.-References:*...
  
  : Plastic Quad Flat Package
• SQFP: Small Quad Flat Package
• TQFP
  TQFP
  A thin quad flat pack is a type of surface-mounted package. TQFPs provide the same benefits of the metric QFP, but are thinner and have a standard lead-frame footprint ....
  
  : Thin Quad Flat Package
• VQFP: Very small Quad Flat Package
• VTQFP: Very Thin Quad Flat Package

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

• Chip carrier
  Chip carrier
  A chip carrier, also known as a chip container or chip package, is a container for a transistor or an integrated circuit. The carrier usually provides metal leads, or "pins", which are sturdy enough to electrically and mechanically connect the fragile chip to a circuit board. This connection may be...
  
   Chip packaging and package types list
• Pin grid array
  Pin grid array
  A pin grid array, often abbreviated PGA, is a type of integrated circuit packaging. In a PGA, the package is square or roughly square, and the pins are arranged in a regular array on the underside of the package...
  
  An alternative integrated circuit pin arrangement design