socket
A socket is a receptacle for holding active and passive components such as central processing units( CPU), caches, memory devices, operational amplifiers, resistor networks, fuses, jumpers, LEDs, batteries and switches, and other components.
For sockets, it is usually assumed that the components can be plugged into the socket. Contact is made with the pins of the components by spring contacts. Sockets can be attached directly to boards, as in SMT technology, or they can be inserted into a breadboard and soldered to the underside of the board
Sockets have the advantage that an upgrade by component exchange is possible without great effort or faulty components can be replaced. That's why CPUs in particular are socketed.
The development of sockets
The development of sockets is characterized by the increasing number of connection pins as well as by the increased mobility, miniaturization and compactness of mobile devices, notebooks, tablets and handhelds, digital cameras, smartphones and camcorders.
In the case of CPU sockets, the development goes back to the basic constellations of the single-inline package( SIP) and the dual-inline package( DIP), which were constantly expanded in their connection rows. Further development led to the square designs, with connection contacts on all sides, such as the Quad Flat Package( QFP). Since even these designs could not cope with the enormous demand for connections, CPU so ckets were developed for microprocessors whose connections are located under the chip in the form of an array, as with Ball Grid Array( BGA) and Pin Grid Array( PGA) with their many variants. Special versions of these sockets bring it to over 900 connection pins.
In order to meet the increasing demands for greater compactness, ever flatter sockets have been developed, mainly for portable devices. In addition, the distance between the connection pins and the thickness of the connection pins have been reduced. While a pin spacing of 2.54 mm (1/10 inch) used to be standard, this has been reduced to 1.27 mm (1/20 inch), to 1 mm, 0.8 mm, 0.65 mm and 0.5 mm( TSOP).