CPU PACKAGE TYPES

FC-LGA4 PACKAGE TYPE

The FC-LGA4 package is used with Pentium® 4 processors designed for the LGA775 socket. FC-LGA4 is short for Flip Chip Land Grid Array 4. FC (Flip Chip) means that the processor die is on top of the substrate on the opposite side from the LAND contacts. LGA (LAND Grid Array) refers to how the processor die is attached to the substrate. The number 4 stands for the revision number of the package.This package consists of a processor core mounted on a substrate land-carrier. An integrated Heat Spreader (IHS) is attached to the package substrate and core and serves as the mating surface for the processor component thermal solution such as a heatsink.You may also see references to processors in the 775-LAND package. This refers to the number of contacts that the new package contains that interface with the LGA775 socket.The pictures below include the LAND Slide Cover (LSC). This black cover protects the processor contacts from damage and contamination and should be retained and placed on the processor whenever it is removed from the LGA775 socket.

FC-PGA2 Package Type

FC-PGA2 packages are similar to the FC-PGA package type, except these processors also have an Integrated Heat Sink (IHS). The integrated heat sink is attached directly to the die of the processor during manufacturing. Since the IHS makes a good thermal contact with the die and it offers a larger surface area for better heat dissipation, it can significantly increase thermal conductivity. The FC-PGA2 package is used in Pentium III and Intel Celeron processor (370 pins) and the Pentium 4 processor (478 pins).

FC-PGA Package Type

The FC-PGA package is short for flip chip pin grid array, which have pins that are inserted into a socket. These chips are turned upside down so that the die or the part of the processor that makes up the computer chip is exposed on the top of the processor. By having the die exposed allows the thermal solution can be applied directly to the die, which allows for more efficient cooling of the chip. To enhance the performance of the package by decoupling the power and ground signals, FC-PGA processors have discrete capacitors and resistors on the bottom of the processor, in the capacitor placement area (center of processor). The pins on the bottom of the chip are staggered. In addition, the pins are arranged in a way that the processor can only be inserted one way into the socket. The FC-PGA package is used in Pentium® III and Intel® Celeron® processors, which use 370 pins.

OOI Package Type

OOI is short for OLGA. OLGA stands for Organic Land Grid Array. The OLGA chips also use a flip chip design, where the processor is attached to the substrate facedown for better signal integrity, more efficient heat removal and lower inductance. The OOI then has an Integrated Heat Spreader (IHS) that helps heatsink dissipation to a properly attached fan heatsink. The OOI is used by the Pentium 4 processor, which has 423 pins.

CPU SOCKET

A CPU socket or CPU slot is a connector on a computer's motherboard that accepts a CPU and forms an electrical interface with it. As of 2007, most desktop and server computers, particularly those based on the Intel x86 architecture, include socketed processors.
Most CPU-sockets interfaces are based on the pin grid (PGA) architecture, in which short, stiff pins on the underside of the processor

package mate with holes in the socket. To minimize the risk of bent pins,

zero insertion force (ZIF) sockets allow the processor to be inserted without any resistance, then grip the pins firmly to ensure a reliable contact after a lever is flipped.
As of 2007, several current and upcoming socket designs use land grid array (LGA) technology instead. In this design, it is the socket which contains pins. The pins contact pads or lands on the bottom of the processor package.
In the late 1990s, many x86 processors fit into slots, rather than sockets. CPU slots are single-edged connectors similar to expansion slots, into which a PBC holding a processor is inserted. Slotted CPU packages offered two advantages: L2 cache memory could be upgraded by installing an additional chip onto the processor PCB, and processor insertion and removal was often easier. However, slotted packages require longer traces between the CPU and chipset, and therefore became unsuitable as clock speeds passed 500MHz. Slots were abandoned with the introduction of AMD's SocketA and Intel's Socket 370.

Motherboard Form Factor

MicroATX Motherboard

The microATX form factor was developed as a natural evolution of the ATX form factor to address new market trends and PC technologies. While offering the same benefits of the ATX form factor specification, the microATX form factor improves upon the previous specification in several key areas. Current trends in the industry indicate that users require a lower-cost solution for their PC needs. Without sacrificing the benefits of ATX, this form factor addresses the cost requirement by reducing the size of the motherboard. The smaller motherboard is made possible by reducing the number of I/O slots supported on the board. The overall effect of these size changes reduces the costs associated with the entire system design. The expected effect of these reductions is to lower the total system cost to the end user.
Through careful designing of a microATX motherboard, an OEM can capitalize on the benefits of a reduction in total system costs. These cost savings come from a reduced-output power supply (see the separate document SFX Power Supply Design Guide), reduced chassis costs, and minimal redesign of existing ATX compliant chassis for backward-compatibility.
microATX benefits also include those found with the current ATX form factor: more I/O space at the rear and reduced emissions from using integrated I/O connectors..

Balanced Technology Extended (BTX) Form Factor

The BTX form factor specification gives developers options to balance thermal management, acoustics, system performance, and size in the system form factors and stylish designs that are desired in today's products. The BTX form factor is a clear break from previous ATX form factor layouts and was developed with emerging technologies such as Serial ATA, USB 2.0, and PCI Express*.
Thermal improvements come primarily from taking advantage of in-line airflow. The BTX defined in-line airflow layout allows many of the main board components (i.e.: processor, chipset, and graphics controller) to utilize the same primary fan airflow, thereby reducing the need for, and noise from, additional system fans. In some cases this also allows fewer and/or less expensive heat sinks to be used when compared to ATX solutions. The system level acoustics are also improved by the reduced air turbulence within the in-line airflow system. The BTX layout supports better component placement for back panel I/O controllers – important as the signal speed of external devices continues to increase. In addition to smaller than microATX system sizes, BTX was designed to scale up to tower size systems using the same core layout by increasing the number of system slots included

ATX FORM FACTOR

ATX was developed as an evolution of the Baby-AT form factor and was defined to address ease of use, support for current and future I/O, support for current and future processor technology, and reduced total system cost.