Component Housing
Surface mount integrated circuit enclosures featuring sixteen flat pads on the underside provide a low profile solution for compact electronic assemblies. The design of lga-16 packaging eliminates the need for protruding leads which reduces the parasitic inductance of the electrical connections. This format is popular for sensors and microcontrollers used in mobile devices where vertical space is limited.
The package relies on a socket or a direct solder connection to the motherboard.
Footprint Specification
Exact dimensions for the pads and the spacing between them are defined by industry standards to ensure compatibility across different vendors. In lga-16 packaging the pins are arranged in a grid or a perimeter configuration depending on the routing needs of the silicon. Small tolerances in pad alignment are necessary to prevent short circuits during the pick and place operation.
The flat bottom allows for a very stable mechanical interface.
Solder Application
Reliability depends on the volume of solder paste deposited during the manufacturing of the printed circuit board. Because lga-16 packaging lacks compliant leads the solder joints must absorb all the mechanical stress from thermal expansion. Inspection using automated optical systems verifies that the fillets are correctly formed.
If the paste is too thin the joint may crack under vibration.
Heat Management
The direct connection between the package pads and the board traces allows for efficient conductive cooling. High power versions of lga-16 packaging often include a central thermal pad to carry heat away from the die. This design keeps the junction temperature low even in densely packed environments.
Designers must account for the local heating of the board when placing other sensitive components nearby.
