An edge connector is the portion of a printed circuit board (PCB) consisting of

trace Trace may refer to: Arts and entertainment Music * ''Trace'' (Son Volt album), 1995 * ''Trace'' (Died Pretty album), 1993 * Trace (band), a Dutch progressive rock band * ''The Trace'' (album) Other uses in arts and entertainment * ''Trace'' ...

s 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), by American jazz pianist Dave Burrell, released in 2004 * ''Expansions'' (McCoy Tyner album), 1970 * ''Expansi ...

s for peripheral cards, such as PCI, PCI Express, and AGP cards.

Socket design

Edge connector sockets consist of a plastic "box" open on one side, with pins on one or both side(s) 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 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 sharp ...

which is clamped onto a

ribbon cable A ribbon cable (also known as multi-wire planar 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 ribb ...

. Alternatively, the other side may be

soldered Solder (; NA: ) is a fusible metal alloy used to create a permanent bond between metal workpieces. Solder is melted in order to wet the parts of the joint, where it adheres to and connects the pieces after cooling. Metals or alloys suitable ...

to a motherboard or

daughtercard 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 slo ...

Uses

Edge connectors are commonly used in

personal computer A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...

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 In computing, memory is a device or system that is used to store information for immediate use in a computer or related computer hardware and digital electronic devices. The term ''memory'' is often synonymous with the term '' primary storag ...

to the system bus. Example expansion peripheral technologies which use edge connectors include PCI, PCI Express, 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 impleme ...

and

Slot A Slot A is the physical and electrical specification for a 242-lead single-edge-connector used by early versions of AMD's Athlon processor. The Slot A connector allows for a higher bus rate than Socket 7 or Super Socket 7. Slot A motherboards use ...

also used edge connectors; the

processor Processor may refer to: Computing Hardware * Processor (computing) **Central processing unit (CPU), the hardware within a computer that executes a program *** Microprocessor, a central processing unit contained on a single integrated circuit (I ...

being mounted on a card with an edge connector, instead of directly to the motherboard as before and since. IBM PCs 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, or a diskette) is an obsolescent 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 w ...

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 was unusual in that it was designed to use a

zero insertion force Zero insertion force (ZIF) is a type of IC socket or electrical connector that requires very little (but not literally zero) force for insertion. With a ZIF socket, before the IC is inserted, a lever or slider on the side of the socket is move ...

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 Commodore 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 adv ...

in 1985, various Amiga models used the 86-pin Zorro I edge connector, which was later reshaped into the internal 100-pin

Zorro II Zorro II is the general purpose expansion bus used by the Amiga 2000 computer. The bus is mainly a buffered extension of the Motorola 68000 bus, with support for bus mastering DMA. The expansion slots use a 100-pin connector and the card form factor ...

slot on the

Amiga 2000 The Amiga 2000, or 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 Ami ...

and later upmarket models.

References

{{reflist Electrical connectors Computer connectors Printed circuit board manufacturing

Socket design

Uses

See also

References