DIP IC Sockets Types and Application

DIP IC Sockets
An IC SOCKET, also known as a chip socket, or a DIP IC socket is an electrical connector used in the field of electronic engineer. The pins of the integrated circuit (IC) connect into the socket making a robust electrical connection without the requirement of soldering. It enables an IC to connect in a circuit without being dedicating through permanent soldering.

The female contacts, also called pin receptacles, form the electrical connections and consist of two main types known as "turned pin" and "dual leaf", and there are advantages to each system.

The turned pin contact usually has tapered entry with a multi-finger spring clip inside it to make a reliable electrical connection. Usually, the more fingers the pin has, the more expensive it is. In contrast, the dual-leaf high compression spring clip is much simpler consisting of a pair of metal spring clips. Generally, contacts consist of phosphor bronze, or beryllium copper, material, and the contact plating can be tin, lead, or gold.

Another very cost-effective method is to use only the pins, known as "DIP terminals", which are available separately without the plastic frame. Usually a carrier temporarily holds the pins for alignment and soldering onto the circuit board. Once the pins are secure, the carrier removes easily leaving the pins on the board. An advantage of this system is that you can still see the PCB traces which otherwise would be covered over by the socket frame. In addition, airflow and thus thermal management is improved.

DIP IC Sockets Applications
what IC sockets are used for, and whether you should use them, 

Usually developers working on new electronic products may have to go through the debugging phase of the stage many times, which involves making changes to the firmware. In such a scenario, it is useful to mount the IC carrying the firmware on a ZIF style socket for easy removal.

Many integrated circuits such as microprocessors are extremely sensitive to heat, and therefore it may not be wise to solder them on a printed circuit board. In such a situation, soldering a chip socket is wiser. With the cost of integrated circuits rising, it is a good idea to recycle the chips for different projects. Hobbyists usually build on prototyping boards, however once the circuit has been tested, the same components may be used again on the final PCB.

Types of Sockets
The main type of socket used by students and hobbyists tends to be the through-hole for dual in-line package (DIP), however you can get sockets for almost any package type including surface-mount devices (SMD).

Zero-Insertion-Force (ZIF) sockets usually have a lever, which engages the contacts to make the electrical connections. Although these are mainly used for microprocessor sockets, it is possible to get these for DIP, PGA, PLCC, and SOIC packages. Typically, devices may be inserted and removed withstanding up to 10 000 cycles.

Ball grid array (BGA) packages also have sockets, which is extremely useful for engineers using these integrated circuits. BGA chips are those without pins, they simply have pads that mate with the pads on the PCB.

The plastic leaded chip carrier (PLCC) socket comes in two types, the clamshell, and the standard open top. These are available for through-hole and SMT mounting.

Pin grid array (PGA) sockets are one of the most widely used, and you can get a socket for almost any PGA IC. If you are into building computers then you will know that almost all the processors currently available have the PGA package, and the socket is usually a ZIF type.

The quad flat package (QFP) sockets are available in clamshell and surface mount type as well.

The small outline integrated circuit (SOIC) specification is one of the most popular, as these packages fit almost anywhere. You can get clamshell and open top adapter sockets for these as well. Amazingly, today, you can even get sockets for display modules as well. For example, right-angled sockets usually mount LCD displays such as a 7-segment display module with the standard pin spacing.
You can get sockets for almost any package type, and here is a small list of package types that are available.

SOIC
SMD / SMT
LQFP
QFN
QFP / TQFP / BQFP