Early CPUs plugged into DIP sockets like most IC of the
time. With each generation of CPU, new sockets or other attachments were
developed. This has evolved to today's motherboards, where you have three types
of sockets. Motherboards made for Advanced Micro Devices (AMD) CPUs have a
traditional CPU socket designed for a Pin Grid Array (PGA) interface.
Motherboards made for Intel CPUs have a Landing Grid Array (LGA) or "bed of
nails" for the CPU to sit on. Some motherboards (for AMD or Intel CPUs) have
CPUs that are soldered directly to the motherboard (usually notebooks or other
compact systems).
PGA socket used by AMD.
LGA
"socket" used by Intel.
Most motherboards now use Zero Insertion Force
(ZIF) sockets, except for motherboards where the CPU is soldered onto the board.
The ZIF socket allows the CPU to be inserted or removed without risking damage
to the CPU or socket pins. Installing a CPU into its socket is a simple matter
of aligning the pins, dropping the CPU in place, and moving the locking lever to
the locked position. Care should be taken not to touch the pins or contact pads
with bare fingers. The pins of an LGA socket are easily damaged, and skin oils
can cause the pads on the CPU to tarnish. The pins of PGA chips are also easily
damaged, although a little more rugged than LGA pins.
