What Is a PLCC Socket?

Most sockets on a motherboard are made to connect the central processing unit (CPU) to the computer, but a plastic leaded chip carrier (PLCC) socket can work with a CPU or a range of other computer chips. A PLCC socket is commonly used when heat can be a problem and by users who regularly swap out the chips. There are several connection types on a PLCC socket — pins, leads and through-holes — that allow many different chips to be placed into the socket. All PLCC sockets are four-sided, either square or rectangular, and have a pin spacing of 0.05 inch (1.27 mm).

While there are many types of PLCC socket units made to accommodate different chips, all of them follow certain design characteristics. The shape of every PLCC connector is either a square or rectangle, because all of the chips that would connect into this connector are one of these two shapes. The spacing between the leads and pins is always 0.05 inch (1.27 mm), not only as a standardized design, but also because the chips have the same spacing size.

The three types of connector units on a PLCC socket are pins, leads and through-holes. Pins and leads are standard on all PLCC connectors, but only some have through-holes. The pins are on the bottom, while the leads are teeth along the connector’s walls and are used for most chips. Through-holes are holes in the bottom of the socket that allow for wiring and also have a stronger bond than just pins connecting into the motherboard.

One of the major reasons for using a PLCC socket instead of a regular soldered socket is that the PLCC variety generates less heat for the motherboard. This allows for complex chips to be added to the motherboard without the computer designer having to worry about additional heat. The copper from which most PLCC connectors are made helps transfer the heat away from the motherboard.

Another reason for a PLCC socket is that it allows users to swap chips in and out of the socket. This application is used by people who hack computers — in the sense of adding extra functions rather than using malicious code — because new chips that were not made for the computer can be added. Removing a chip from the PLCC connector can be difficult, so a PLCC extractor tool is normally used to help remove the chip.