Submitted by: DAVID SMITH
IC (Integrated Circuit) means an assemblage of electronic components such as resistors, transistors, capacitors, etc. All these are crammed into a very small chip and attached with each other to acquire a common objective.
The IC package is what encases the die of integrated circuit and extends it out into a device we can more conveniently attach to. Every external connection on the die is linked via a very small piece of gold wire to a pad or pin on the packaging. The silver, extruding terminals on an IC are the pins. These pins carry out the work to link to different components of a circuit. These are of highest significance to us whereas they are what will go on to connect to the remaining elements and wires in a circuit.
Every IC is polarized and each is pin is distinctive in case of both position and operation. For this reason, it is necessary for the package to have some way to impart which pin is which. For most ICs, a dot or a notch (in some cases, both or sometimes anyone of them) designates the first pin. If you can recognize the first pin, the rest of the pin numbers increase according to the sequence as you move counter-clockwise around the chip.
The way how the IC packages mount to a circuit board is one of the primary distinguishable package type characteristics. Mainly there are two mounting types: through-hole (PTH) or surface-mount (SMD or SMT). All packages fall into one of these two mounting types. Usually through-hole packages are bigger in size and much simpler to work with. They are designed especially to be pierced through one side of a board and dredged to the other side.
Surface-mount packages can be small to minuscule in size. They are all intended to be installed on one side of a circuit board and be dredged to the surface. Most of the times, the pins of a SMD package thrust out the side. These also steep to the chip, or are sometimes set out in a matrix on the bottom of the chip. ICs with surface mount packages are not very suitable to assemble with hands. Generally special tools are needed to assist in the process.
There are numerous varieties of IC packages, each of which has distinctive measures, mounting styles, and/or pin-enumerations. These packages are batched into three major categories: Dual In-line Packages, Grid Arrays and Chip Carriers. Each package, regardless of the category has a body style that scales with pin count. The number of pins determines the physical dimension of the package, the name of the package does not.
1. Dual In-line Packages [DIP], or Dual In-Line [DIL] packages are packages with two rows of leads on two sides of the package. DIP ICs may be through-hole [PDIP or CERDIP] or SMT package [SOJ or SOIC].
2. Quad Flat Packs or Chip Carriers are square packages [or nearly square], with leads on all four sides Chip Carriers, as in PLCCs and other variants are strictly Surface Mount Technology (SMT).
3. Grid Arrays are those type packages that have their pins arranged in a grid. The pin grid may consist of Leads, pads, or solder balls on an area array. The through hole variant is called a PGA, while the SMT variant might be called LGA or BGA.
About the Author: David Smith, Senior Vice President of
USComponent.com
, an IGBT power transistor module distributor since 2001.
Source:
isnare.com
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