They connect the processor to the system and allow communication between components.
They connect the processor to the system and allow communication between components.
In short, the pins are small metal wires that can break easily. It’s unclear why manufacturers haven’t changed how they connect them to make it stronger.
They(PGA) aren't delicate. The replacement for them on AMD CPUs is LGA. I've never faced any pin problems, and I've assembled PCs for as long as computers have existed. On my Q9550 build, I swapped a motherboard and CPU using an LGA motherboard. That's been my experience so far.
Other ways to achieve this involve different approaches. For pads near each other, the pins are positioned so the socket features a gold-plated copper surface for better grip. Various designs exist, such as Intel's where pins sit inside the socket instead of on the CPU. This is essentially the reverse configuration. Since flexible plastic isn't conductive, metals are necessary. The only viable alternative is soldering directly, which we avoid for our main desktops.
Modern CPUs consist of numerous components that require electrical and data connections from the motherboard. This creates a high demand for many links. Pins offer the optimal solution for compact integration while supporting modular design. An alternative is a ball grid array, which permits soldering the CPU to the board but limits flexibility. If you have an improved idea, major chip or motherboard producers would appreciate hearing it so they can secure patents and gain an edge by reducing required RAMs.
The main concern is achieving density for contemporary processors. When examining a modern CPU with 1300-1700 pins, it’s essential every pin is present for stable connections. In a modern AMD socket using PGA, pins slide into the socket that features metal contacts on both sides. However, it’s only when lowering the retention arm that the top of the socket shifts, securing the pins in place. With Intel’s BGA design, the sockets have springs that push against the bottom pads. That’s why the retaining bracket must be firmly closed to ensure each spring pushes properly. Personally, I’ve only ever suffered damage from a single CPU and zero motherboards due to socket issues over three decades of PC building. As long as you handle CPUs gently, cover sockets when they’re not in use, and store PGA CPUs in clamshells. It’s always worth exploring fresh concepts for improved designs.
The most common processors types are PGA (pin grid array) and LGA (land grid array) PGA = there's pins soldered on the bottom of the CPU and you insert the CPU in a socket and you get a very good grip on every pin LGA = there's tiny pads (squares, hexagons, rombs, whatever) or gold plated material on the bottom of the cpu and the socket has flexible contacts that press on the pads to make contact. When you place the CPU on the socket, the CPU's weight bends down the contacts a bit. There's pros and cons for each method. Pins are safer, there's less risk of damaging CPU compared to damaging motherboard socket. CPUs are shipped in plastic shells or boxes, so no risk of damaging pins during transport. Only time you risk damaging pins is when you take it out and insert in socket - you may drop it and bend a pin, which can be straightened out. In very rare cases, you may break a pin and even then you can solder another one with the right equipment Intel moved to LGA because they didn't want to deal with processors with bent or broken pins, they basically moved the losses from their end to the motherboard manufacturer's end. There's much higher risk to have a screwdriver or the corner of the CPU drop on the LGA socket and permanently damage one or more contacts in the socket, and your motherboard is gone... replacing a socket can cost up to $100 or more at authorized service places. On one hand there's the benefit of PGA that the pins are grabbed from two sides by the socket, so there's a lot of surface area between socket and pins, so you don't need a lot of pins to transfer power to the CPU... in contrast the pads often have very small tips, small area where it makes contact with the cpu, so you need more pins to carry the same amount of power. There's also higher risk of having some dirt or... anything, like for example a strand of hair, be between the LGA socket and the CPU and cause a contact to not touch a pad on the cpu. However there's some downsides. Pins are long and because of that, there's longer distances between the circuit board and the actual cpu, and the pins themselves can have extra inductance or act like tiny antennas picking up noise from the other pins. This can affect the CPU reaching higher frequencies, or it can be an issue where you have lots of pins close together. With LGA, the spring like contacts are shorter, so overall there's less length of wire between the motherboard and the cpu die. LGA also allows you to pack more pins in an amount of space, that's why AMD went with LGA on Threadripper and Epyc, that and what I said in the paragraph above, shorter distance, better signals etc .. it's an issue when you have 4-8 channels and 128 pci-e lanes and lots of stuff you need pins for. Makes sense for AMD to move to LGA for better signals, when they're gonna do pci-e 5.0 (probably they're gonna assume socket will still be here on pci-e 6.0) , ddr5, and other high bandwidth stuff.