PLCC Socket SMD Mount

A plastic leaded chip carrier (PLCC) is a socket used for j-leaded and leadless integrated circuits (IC) to make an electrical connection without the requirement of soldering onto the PCB. It accepts JDEC standard MS-016 and MS-018 compliant IC packages. The socket is available in through-hole and surface-mount versions for soldering, and the sizes range from 20 pin to 100 pin. There are three main systems used in industry for securing the IC in the carrier; flip-top or clamshell, auto-eject, and open-top. The design of this socket usually complies with the EIA / JEDEC outline.

Dimensions

For through-hole, the pins for mounting the socket are usually dual row in-line forming a 2.54 mm grid. The height above the PCB is usually 8.3 mm. For surface-mount, the pins are usually single row on a 1.27 mm grid, and the height above the PCB is 4.6 mm. These sockets are usually available in the following number of pins.

• 28 pin
• 32 pin
• 44 pin
• 52 pin
• 68 pin
• 84 pin
• 100 pin

Application

Nearly all the modern motherboards hold the BIOS flash IC in a PLCC socket such as this, which is extremely useful if you need to change the firmware on the IC. I recently bought a faulty high-end motherboard on eBay that required the correct firmware. The first step was to remove the existing SMD chip and solder this SMD PLCC socket in its place. You can then flash the BIOS chip correctly to repair it and then return it into this socket. It pops back into the socket and everything works! It is also useful if you are into reverse engineering embedded systems, or perhaps you are a Coreboot / Linux Developer.

This Article Continues...