Near Hermetic Cavity Electronic Packaging Solutions Beyond B-Staged Epoxy Lid-Sealing
If we closely examine the protection required for cavity packaging with single and multiple chips, there are other complementary sealing solutions meeting the protection against moisture-ionic-corrosive gases combination with sealing coating and sealant that have LCP level of the barrier. For example, instead of relying on the lid-seal bonding for the barrier, if the geometry configuration allowed or if deemed more convenient for inline manufacturing process rather than batch processing:
- The lid-sealing can be done with instant melt-bonding B-staged or pre-applied adhesive that may not have the only temporary capability for the final lid-sealing requirements.
- One possible process is to instantly pick-and-place and melt-bond lid with pre-applied TP7130 (from AIT) at 150°C under an inert environment. Subsequently, high-temperature capable lid-seal can be applied onto the lid rim edge to provide additional mechanical strength such as LS-LCXP7450 which has FLUOROSEAL® level of moisture and corrosive gases barrier. This lid-sealing paste can be dispensed and cured without applying any additional pressure or inert gas provision.
- Another possible process is for use in device lid-sealing that may be difficult to use traditional lid-sealing processes of controlled uniform pressure and temperature for an extended time such as extra-large modules or transparent imaging devices. In this case, the rapid curing lid-seal adhesive or rapid UV curing adhesive for partial curing at higher temperature with UV for balancing cavity pressure. Rim-edge sealants such as FLUOROSEAL® LS-CXP7450 or LS-SC7150 may be subsequently used to provide the ultimate moisture and the corrosive gases barrier layer.
The following are some examples of the FLUOROSEAL® moisture and corrosive gases barrier protection: