Zero insertion force

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ZIF socket for DIP-28W package Textoolfassung 28 (smial).jpg
ZIF socket for DIP-28W package
A large ZIF socket (Socket A) Socket 462.saa.jpeg
A large ZIF socket (Socket A)
Zero insertion force connector from a Philips C5-2 ultrasound probe. Zero Insertion Force Connector.png
Zero insertion force connector from a Philips C5-2 ultrasound probe.
A PIC microcontroller (wide SOIC-28) in a ZIF socket PIC16LF870 in SOIC Socket (cropped).jpg
A PIC microcontroller (wide SOIC-28) in a ZIF socket

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 moved, pushing all the sprung contacts apart so that the IC can be inserted with very little force - generally the weight of the IC itself is sufficient and no external downward force is required. The lever is then moved back, allowing the contacts to close and grip the pins of the IC. ZIF sockets are much more expensive than standard IC sockets and also tend to take up a larger board area due to the space taken up by the lever mechanism. Typically, they are only used when there is a good reason to do so.

Contents

Design

Demonstration of a PGA-ZIF socket (AMD 754).

A normal integrated circuit (IC) socket requires the IC to be pushed into sprung contacts which then grip by friction. For an IC with hundreds of pins, the total insertion force can be very large (hundreds of newtons), [1] leading to a danger of damage to the device or the circuit board. Also, even with relatively small pin counts, each pin extraction is fairly awkward and carries a significant risk of bending pins, particularly if the person performing the extraction hasn't had much practice or if the board is crowded. Low insertion force (LIF) sockets reduce the issues of insertion and extraction, but because of its lower insertion force than a conventional socket, are likely to produce less reliable connections.

Large ZIF sockets are only commonly found mounted on PC motherboards, being used from about the mid 1990s forward. These CPU sockets are designed to support a particular range of CPUs, allowing computer retailers and consumers to assemble motherboard/CPU combinations based on individual budgets and requirements. [1] The rest of the electronics industry has largely abandoned sockets (of any kind) and instead moved to the use of surface mount components soldered directly to the board.

Smaller ZIF sockets are commonly used in chip-testing and programming equipment, e.g., programming and testing on EEPROMs, Microcontrollers, etc. [2]

Universal test sockets

Programming device for a PIC microcontroller, with a dual in-line ZIF socket Picstart plus.jpg
Programming device for a PIC microcontroller, with a dual in-line ZIF socket

Standard DIP packages come in a number of widths (measured between pin centers), with 0.3 in (7.62 mm) and 0.6 in (15.24 mm) being the most common. To allow the design of programmers and similar devices that support a range of devices universal test sockets are produced. These have wide slots into which the pins drop allowing devices of differing widths to be inserted.

Ball grid array sockets

ZIF sockets can be used for ball grid array chips, particularly during development. These sockets tend to be unreliable, failing to grab all the solder balls. Another type of BGA socket, also free of insertion force but not a "ZIF socket" in the traditional sense, does a better job by using spring pins to push up underneath the balls.

ZIF wire-to-board connectors

A pair of ZIF connectors, with the flexible flat cable that connects to them. ZIF connector and FFC.jpg
A pair of ZIF connectors, with the flexible flat cable that connects to them.

ZIF wire-to-board connectors are used for attaching wires to printed circuit boards inside electronic equipment. An example would be the cable between the LCD screen and motherboard in laptops. The wires, often formed into a ribbon cable, are pre-stripped and the bare ends are placed inside the connector. The two sliding parts of the connector are then pushed together, causing it to grip the wires. The most important advantage of this system is that it does not require a mating half to be fitted to the wire ends, therefore saving space and cost inside miniaturised equipment. See flexible flat cable.

Hard disk drives

ZIF tape connections are used for connecting Parallel ATA and Serial ATA disk drives (mostly drives in the 1.8-inch form factor). PATA hard drives with ZIF-style connectors were used primarily in the design of ultra-portable notebooks. They have since been phased out, as SATA has a relatively small-form-factor connector by default. Mini-SATA (mSATA) can be used where even smaller form factors are required.

Internally, nearly all hard drives use ZIF tape to connect their circuit board to their platter motor. ZIF tape connections are also heavily used in the design of the iPod range of portable media players, not just for the hard drive but also for other connections from the main circuit board. Three types of ZIF connectors are known to exist on 1.8 inch PATA drives. ZIF-24, ZIF-40, and ZIF-50 have 24, 40, and 50 pins respectively.

See also

Related Research Articles

<span class="mw-page-title-main">Parallel ATA</span> Interface standard for the connection of storage devices

Parallel ATA (PATA), originally AT Attachment, also known as Integrated Drive Electronics (IDE), is a standard interface designed for IBM PC-compatible computers. It was first developed by Western Digital and Compaq in 1986 for compatible hard drives and CD or DVD drives. The connection is used for storage devices such as hard disk drives, floppy disk drives, optical disc drives, and tape drives in computers.

<span class="mw-page-title-main">Backplane</span> Group of electrical connectors specifically aligned

A backplane or backplane system is a group of electrical connectors in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors, forming a computer bus. It is used to connect several printed circuit boards together to make up a complete computer system. Backplanes commonly use a printed circuit board, but wire-wrapped backplanes have also been used in minicomputers and high-reliability applications.

<span class="mw-page-title-main">Motherboard</span> Main printed circuit board (PCB) for a computing device

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<span class="mw-page-title-main">Dual in-line package</span> Type of electronic component package

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<span class="mw-page-title-main">Electrical connector</span> Device used to join electrical conductors

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<span class="mw-page-title-main">SATA</span> Computer bus interface for storage devices

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<span class="mw-page-title-main">Ball grid array</span> Surface-mount packaging that uses an array of solder balls

A ball grid array (BGA) is a type of surface-mount packaging used for integrated circuits. BGA packages are used to permanently mount devices such as microprocessors. A BGA can provide more interconnection pins than can be put on a dual in-line or flat package. The whole bottom surface of the device can be used, instead of just the perimeter. The traces connecting the package's leads to the wires or balls which connect the die to package are also on average shorter than with a perimeter-only type, leading to better performance at high speeds.

<span class="mw-page-title-main">Pin grid array</span> Type of integrated circuit packaging with the pins mounted on the underside of the package

A pin grid array (PGA) is a type of integrated circuit packaging. In a PGA, the package is square or rectangular, and the pins are arranged in a regular array on the underside of the package. The pins are commonly spaced 2.54 mm (0.1") apart, and may or may not cover the entire underside of the package.

<span class="mw-page-title-main">Edge connector</span> Connector type for printed circuit boards

An edge connector is the portion of a printed circuit board (PCB) consisting of traces leading to the edge of the board that are intended to plug into a matching socket. The edge connector is a money-saving device because it only requires a single discrete female connector, and they also tend to be fairly robust and durable. They are commonly used in computers for expansion slots for peripheral cards, such as PCI, PCI Express, and AGP cards.

<span class="mw-page-title-main">ATX</span> Motherboard and power supply configuration

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<span class="mw-page-title-main">CPU socket</span> Circuit board-microprocessor connection

In computer hardware, a CPU socket or CPU slot contains one or more mechanical components providing mechanical and electrical connections between a microprocessor and a printed circuit board (PCB). This allows for placing and replacing the central processing unit (CPU) without soldering.

<span class="mw-page-title-main">Land grid array</span> Type of surface-mount packaging for integrated circuits

The land grid array (LGA) is a type of surface-mount packaging for integrated circuits (ICs) that is notable for having the pins on the socket — as opposed to pins on the integrated circuit, known as a pin grid array (PGA). An LGA can be electrically connected to a printed circuit board (PCB) either by the use of a socket or by soldering directly to the board.

<span class="mw-page-title-main">Low insertion force</span>

Low insertion force (LIF) is a technology used in integrated circuit sockets that are designed so the force required to insert or remove a package is low.

<span class="mw-page-title-main">Socket 1</span>

Socket 1, originally called the "OverDrive" socket, was the second of a series of standard CPU sockets created by Intel into which various x86 microprocessors were inserted. It was an upgrade to Intel's first standard 169-pin pin grid array (PGA) socket and the first with an official designation. Socket 1 was intended as a 486 upgrade socket, and added one extra pin to prevent upgrade chips from being inserted incorrectly.

<span class="mw-page-title-main">Socket 2</span>

Socket 2 was one of the series of CPU sockets into which various x86 microprocessors were inserted. It was an updated Socket 1 with added support for Pentium OverDrive processors.

<span class="mw-page-title-main">Molex connector</span> Two-piece pin-and-socket connector

A Molex connector is a two-piece pin-and-socket interconnection which became an early electronic standard. Developed by Molex Connector Company in the late 1950s, the design features cylindrical spring-metal pins that fit into cylindrical spring-metal sockets, both held in a rectangular matrix in a nylon shell.

<span class="mw-page-title-main">Computer fan</span> Miniature fan used in a computer for active cooling

A computer fan is any fan inside, or attached to, a computer case used for active cooling. Fans are used to draw cooler air into the case from the outside, expel warm air from inside and move air across a heat sink to cool a particular component. Both axial and sometimes centrifugal (blower/squirrel-cage) fans are used in computers. Computer fans commonly come in standard sizes, such as 92 mm, 120 mm, 140 mm, and even 200–220 mm. Computer fans are powered and controlled using 3-pin or 4-pin fan connectors.

<span class="mw-page-title-main">Power supply unit (computer)</span> Internal computer component that provides power to other components

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<span class="mw-page-title-main">M.2</span> Standard for miniature computer expansion cards

M.2, pronounced m dot two and formerly known as the Next Generation Form Factor (NGFF), is a specification for internally mounted computer expansion cards and associated connectors. M.2 replaces the mSATA standard, which uses the PCI Express Mini Card physical card layout and connectors. Employing a more flexible physical specification, M.2 allows different module widths and lengths, which, paired with the availability of more advanced interfacing features, makes M.2 more suitable than mSATA in general for solid-state storage applications, particularly in smaller devices such as ultrabooks and tablets.

References

  1. 1 2 Scott Mueller, Upgrading and Repairing PCs, Eleventh Edition, Que, 1999, ISBN   0-7897-1903-7 pages 87-88
  2. Najamuz Zaman, Automotive Electronics Design Fundamentals, Springer, 2015, ISBN   331917584X, page 35