B STAGED DIE PASSIVATION FOR RF INTERCONNECT
Publication Date: 2018-Sep-17
The IP.com Prior Art Database
The invention discloses methods of attaching a die to substrates with pre drilled holes/vias such that the vias/holes will not get filled with adhesive. It also keeps adhesive away from Rf structures to maintain an air dielectric. A photo imageable adhesive is applied at the wafer level. The photo imageable adhesive material allows precise removal of adhesive from areas such as I/O bond pads and RF structures, where adhesive is not wanted. Once these areas are cleared of adhesive, the material is B-staged to form a stable layer. Next the die with adhesive may be attached to a substrate that has vias/holes pre-made to line up with the IO or bumps on the die. Once attached, the adhesive is fully cured to lock the die in place. The substrate then may be metalized to form electrical interconnects. Advantages of the invention are that RF elements are accommodated to keep air dielectric and avoid adhesive coating.