
An edge connector is the portion of a
printed circuit board
A printed circuit board (PCB), also called printed wiring board (PWB), is a Lamination, laminated sandwich structure of electrical conduction, conductive and Insulator (electricity), insulating layers, each with a pattern of traces, planes ...
(PCB) consisting of
traces leading to the edge of the board that are intended to plug into a matching
socket
Socket may refer to:
Mechanics
* Socket wrench, a type of wrench that uses separate, removable sockets to fit different sizes of nuts and bolts
* Socket head screw, a screw (or bolt) with a cylindrical head containing a socket into which the hexag ...
. The edge connector is a money-saving device because it only requires a single discrete
female connector (the male connector is formed out of the edge of the PCB), and they also tend to be fairly robust and durable. They are commonly used in computers for
expansion slot
Expansion may refer to:
Arts, entertainment and media
* ''L'Expansion'', a French monthly business magazine
* Expansion (album), ''Expansion'' (album), by American jazz pianist Dave Burrell, released in 2004
* Expansions (McCoy Tyner album), ''Ex ...
s for peripheral cards, such as
PCI,
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe, is a high-speed standard used to connect hardware components inside computers. It is designed to replace older expansion bus standards such as Peripher ...
, and
AGP cards.
Socket design
Edge connector sockets consist of a plastic "box" open on one side, with pins on one or both sides of the longer edges, sprung to push into the middle of the open center. Connectors are often
keyed to ensure the correct
polarity, and may contain bumps or notches both for polarity and to ensure that the wrong type of device is not inserted. The socket's width is chosen to fit to the thickness of the connecting PCB.
The opposite side of the socket is often an
insulation-piercing connector which is clamped onto a
ribbon cable
A ribbon cable is a cable with many conducting wires running parallel to each other on the same flat plane. As a result, the cable is wide and flat. Its name comes from its resemblance to a piece of ribbon.
Ribbon cables are usually seen fo ...
. Alternatively, the other side may be
soldered to a
motherboard
A motherboard, also called a mainboard, a system board, a logic board, and informally a mobo (see #Nomenclature, "Nomenclature" section), is the main printed circuit board (PCB) in general-purpose computers and other expandable systems. It ho ...
or
daughtercard.
Uses

Edge connectors are commonly used in
personal computer
A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...
s for connecting
expansion card
In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus sl ...
s and
computer memory
Computer memory stores information, such as data and programs, for immediate use in the computer. The term ''memory'' is often synonymous with the terms ''RAM,'' ''main memory,'' or ''primary storage.'' Archaic synonyms for main memory include ...
to the
system bus
A system bus is a single computer bus that connects the major components of a computer system,
combining the functions of a data bus to carry information, an address bus to determine where it should be sent or read from, and a control bus to det ...
. Example expansion peripheral technologies which use edge connectors include
PCI,
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe, is a high-speed standard used to connect hardware components inside computers. It is designed to replace older expansion bus standards such as Peripher ...
, and
AGP.
Slot 1
Slot 1 refers to the physical and electrical specification for the connector used by some of Intel's microprocessors, including the Pentium Pro, Celeron, Pentium II and the Pentium III. Both single and dual processor configurations were impl ...
and
Slot A also used edge connectors; the
processor being mounted on a card with an edge connector, instead of directly to the motherboard as before and since.
IBM PC
The IBM Personal Computer (model 5150, commonly known as the IBM PC) is the first microcomputer released in the List of IBM Personal Computer models, IBM PC model line and the basis for the IBM PC compatible ''de facto'' standard. Released on ...
s used edge connector sockets attached to ribbon cables to connect 5.25"
floppy disk drive
A floppy disk or floppy diskette (casually referred to as a floppy, a diskette, or a disk) is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a ...
s. 3.5" drives use a pin connector instead.
Video game cartridges typically take the form of a PCB with an edge connector: the socket is located within the console itself. The
Nintendo Entertainment System
The Nintendo Entertainment System (NES) is an 8-bit home video game console developed and marketed by Nintendo. It was first released in Japan on 15 July 1983 as the and was later released as the redesigned NES in several test markets in the ...
was unusual in that it was designed to use a
zero insertion force edge connector:
instead of the user forcing the cartridge into the socket directly, the cartridge was first placed in a bay and then mechanically lowered into position.
Starting with the
Amiga 1000
The Amiga 1000, also known as the A1000, is the first personal computer released by Commodore International in the Amiga line. It combines the 16/32-bit Motorola 68000 CPU which was powerful by 1985 standards with one of the most advanced grap ...
in 1985, various Amiga models used the 86-pin Zorro I edge connector, which was later reshaped into the internal 100-pin
Zorro II slot on the
Amiga 2000
The Amiga 2000 (A2000) is a personal computer released by Commodore in March 1987. It was introduced as a "big box" expandable variant of the Amiga 1000 but quickly redesigned to share most of its electronic components with the contemporary Am ...
and later upmarket models.
See also
*
Pin header
A pin header (or simply, header) is a form of electrical connector. A male pin header consists of one or more rows of metal pins molded into a plastic base, often apart, though available in many spacings. Male pin headers are cost-effective du ...
connector
*
Insulation-displacement connector
An insulation-displacement contact (IDC), also known as insulation-piercing contact (IPC), is an electrical connector designed to be connected to the conductor(s) of an insulated cable by a connection process which forces a selectively sharpe ...
References
{{reflist
Electrical connectors
Computer connectors
Printed circuit board manufacturing