May 31, 2015, anysilicon
Lidless BGA package essentially offers one main advantage compared to a heatspreader-BGA packages: better thermal performance. The second advantage of the lidless BGA is lower cost due to the fact that a heatspreader is not used in lidless BGA configuration. This article will cover the thermal properties of the lidless BGA package.
In the lidless BGA package, exposure of the die allows for direct contact between the die and heat sink, which increases the thermal performance of the chip. While lidless BGA packages achieve better thermal performance, they present a few tricky challenges in handling because lidless BGA does not consists of a heatspreader which makes the pick and place slightly trickier.
Lidless BGA packages basically enable a direct die contact to an external heat sink, ensuring the lowest thermal impedance between the flip chip die and the attached heat sink. With a properly designed heat-sink and Thermal Interface Material (TIM), lidless BGA package can achieve thermal resistance values better than a lidded package.
It is advised to select the thermal interface material (TIM) early in the design phase because TIMs can be the limiting factors in the expense of thermal management designs. This choice depends on cost targets, package application, manufacturing dynamics, and the performance requirements of the thermal solution.