Patent ID: 8522426

Claim:
A method of mounting ball grid array (BGA) packages to a printed wire board (PWB), comprising: providing a BGA package, said BGA package comprising a substrate, an array of solder balls, an integrated circuit (IC) die and other internal devices, a lid and a plurality of discrete beads of a first adhesive, wherein the array of solder balls is on the bottom of the substrate, said integrated circuit (IC) die and the other internal electrical devices have associated internal solder attachments and conductors on top of the substrate in electrical contact with the solder balls through vias in the substrate, a said plurality of discrete beads on the substrate around both the IC die and other devices to attach the lid to the substrate, form pressure relief vents and define a gap between the lid and the substrate around the perimeter of the package, said lid having a polarity through-hole formed therein outside the footprint of the discrete beads, said through-hole being an indicator of the orientation of the BGA package; applying a continuous bead of a second adhesive around the perimeter of the BGA package to seal the gap between the lid and substrate, said continuous bead of the second adhesive and said discrete beads of the first adhesive defining a channel through the pressure relief vents to the polarity through-hole; reflow soldering the BGA package to the PWB at an elevated temperature using solder flux, said IC die achieving elevated temperature pressure relief through the pressure relief vents along said channel and out the polarity through-hole; applying a seal to plug the polarity through-hole; and washing the PWB and the BGA package in an aqueous cleaner solution to remove flux residues on the PWB, said continuous bead of the second adhesive and said seal sealing the BGA package to form a cleaner solution barrier that prevents the solution from contacting the internal conductors.