What holds CPU?

Answer 1

The microprocessor (which contains the CPU and sometimes other circuits) is usually attached to the motherboard by a zero insertion force socket (which is soldered to the motherboard). On some motherboards the microprocessor is soldered directly to the motherboard.

Answer 2

Circuit boards in a computer are plugged into a backplane. The underside (back) of the backplane has many pins corresponding to connectors coming from the circuit boards. These pins have wires wrapped around them that connect to other pins on the backplane connecting the circuit boards together so that the whole assembly performs the functions necessary for the computer.

In larger computers, there may be more than one backplane and they are connected to each other with wires, usually in the form a a wiring harness which has multiple wires held together by a sheath, clamps, or cable ties.

Smaller computers such as personal computers (PCs) do not have or need a backplane. They have most of the functionality on a single board called a motherboard (or mainboard) and additional circuit boards plug into one or more slots on the motherboard.

Answer 3

Older CPUs were held in primarily through a sliding latch that pushed the processor firmly into place. LGA775 sockets have a small door that closes over the CPU, and is then latched down.