Epoxy Molding Compound Moisture Absorption Kinetic Fundamentals
Moisture kinetics in epoxy molding compounds dictate reflow vapor pressure, package strain, and MSL floor life across surface mount assembly lines.
LGA Packaging
Surface Interconnect
Integrated circuit housing technology utilizes a grid of flat conductive pads on the underside of a package to establish electrical contact with a printed circuit board. Unlike leaded components, lga packaging relies on a socket or a solder paste interface to form a connection. This arrangement reduces the total height of the assembly and minimizes the parasitic inductance caused by long metal leads.
It is a preferred format for high speed processors and complex sensor modules. The absence of long leads also reduces the overall electromagnetic signature of the device.
Thermal Management
The direct contact between the package body and the circuit board facilitates the efficient transfer of heat away from the silicon die. In lga packaging, the large surface area of the pads acts as a thermal path to the internal copper planes of the substrate. This cooling capability allows for higher power densities without reaching critical temperatures.
Designers often include a central thermal pad to further enhance the dissipation of energy.
Assembly Advantage
Elimination of fragile pins reduces the risk of damage during shipping and automated handling. Because lga packaging uses a flat profile, it is less prone to the lead bending issues that affect other surface mount components.
Pin Density
High input and output counts are achievable within a compact footprint by arranging the pads in a dense matrix. Through lga packaging, a manufacturer can fit hundreds of connections into a square centimeter of board space. This density is necessary for advanced field programmable gate arrays and multi axis inertial measurement units.
The reduced distance between the chip and the board also improves signal integrity for high frequency data transmissions.