A BGA socket is a central processing unit (CPU) socket that uses a type of surface mount-based integrated circuit packaging called ball grid array. It is similar to other form factors such as pin grid array (PGA) and land grid array (LGA) in that the contact used for attaching the CPU, or processor, to the motherboard for physical support and electrical connectivity are neatly arranged in a grid-like format. BGA, however, is named after its type of contacts, which are small solder balls. This sets it apart from the PGA, which uses pin holes; and the LGA, which comprises pins. BGA, however, has yet to achieve the popularity of the aforementioned chip form factors.
Like other sockets, the BGA socket is usually named after the number of contacts it bears. Examples include BGA 437 and BGA 441. Also, the BGA prefix can vary depending on the variant of the form factor that the socket is using. For instance, the FC-BGA 518, a 518-ball socket, uses the flip-chip ball grid array variant, which means that it flips the computer chip so that the back of its die is exposed. This is particularly advantageous for reducing the heat of the processor by placing a heatsink on it.
Several other BGA variants exist. For instance, ceramic ball grid array (CBGA) and plastic ball grid array (PBGA) denote the ceramic and plastic material, respectively, that the socket is made of. Micro ball grid array (MBGA) is an example of describing the size of the balls that comprise the array. In some instances, prefixes are combined to denote BGA sockets that have more than one distinctive attribute. A prime example is mFCBGA, or micro-FCBGA, which means that the BGA socket has smaller ball contacts and adheres to the flip-chip form factor.
A major advantage of the BGA socket is its ability to use hundreds of contacts with considerable spacing so that they do not join each other during the soldering process. Also, with the BGA socket there is less conduction of heat between the component and the motherboard, and it demonstrates superior electrical performance to other types of integrated circuit packaging. There are some disadvantages, however, as the contacts of the BGA format are not as flexible as other types. Moreover, BGA sockets are generally not as mechanically reliable as those of PGA and LGA. As of May 2011, it lags behind the two aforementioned form factors, although semiconductor company Intel Corporation uses the socket for its Intel Atom low-voltage and lowered-performance brand.
