All Devices: How much weight can the Lattice lead free BGA package tolerate (for heat sink mounting)?
Assuming the pressure on the package is uniform and evenly distributed over the entire topside surface, the loading will be on the BGA ball. Each lead free ball can withstand ~3N of force (roughly .3 kg) before permanent deformation.
Assuming a 484 pin package, the weight can be calculate as below:
.3 * 484 = 145.2 Kg
Generally, it should not exceed 10% of this value or 14.2 Kg. This is more than sufficient to mount the heat sink.