Methods for the production of microelectronic packages having radiofrequency stand-off layers
View Patent ↗Microelectronic packages and methods for fabricating microelectronic packages are provided. In one embodiment, the method includes producing a plurality of vertically-elongated contacts in ohmic contact with interconnect lines contained within one or more redistribution layers built over the frontside of a semiconductor die. A molded radiofrequency (RF) separation or stand-off layer is formed over the redistribution layers through which the plurality of vertically-elongated contacts extend. An antenna structure is fabricated or otherwise provided over the molded RF stand-off layer and electrically coupled to the semiconductor die through at least one of the plurality of vertically-elongated contacts.
1. A method for fabricating a microelectronic package, comprising:
producing a plurality of vertically-elongated contacts in ohmic contact with interconnect lines contained within at least one redistribution layer built over a molded panel containing a plurality of semiconductor die, the molded panel having a frontside at which the plurality of semiconductor die is exposed, the at least one redistribution layer produced over the frontside of the molded panel and the plurality of semiconductor die;
forming a molded radiofrequency (RF) stand-off layer over the frontside of the molded panel and on the at least one redistribution layer such that the plurality of vertically-elongated contacts extends through the molded RF stand-off layer; and
providing a plurality of antenna structures over the molded RF stand-off layer and electrically coupled to the plurality of semiconductor die through the plurality of vertically-elongated contacts;
wherein the at least one-redistribution layer comprises a plurality of redistribution layers having an outer dielectric layer in which openings are formed exposing regions of the interconnect lines, and wherein producing a plurality of vertically-elongated contacts comprises depositing electrically-conductive bodies in the openings and in ohmic contact with the exposed regions of the interconnect lines.
2. The method of claim 1 wherein the at least one redistribution layer comprises a plurality of redistribution layers containing a last dielectric layer, and wherein the molded RF stand-off layer is formed to have a thickness at least twice the thickness of the last dielectric layer included within the plurality of redistribution layers.
3. The method of claim 1 wherein the plurality of vertically-elongated contacts is produced prior to formation of the molded RF stand-off layer.
4. The method of claim 3 wherein forming a molded RF stand-off layer comprises:
depositing a mold material over the at least one redistribution layer and the plurality of vertically-elongated contacts; and
curing the mold material to produce the molded RF stand-off layer.
5. The method of claim 4 wherein the molded RF stand-off layer covers the plurality of vertically-elongated contacts, and wherein the method further comprises planarizing the molded RF stand-off layer to impart the molded RF stand-off layer with a planar outer surface through which the plurality of vertically-elongated contacts is exposed.
6. The method of claim 1 wherein the electrically-conductive bodies comprise solder balls.
7. The method of claim 1 wherein the electrically-conductive bodies each comprise a copper core surrounded by a solder plating, and wherein the method further comprises planarizing the electrically-conductive bodies after forming the molded RF stand-off layer to partially remove the solder plating and expose the copper core through the molded RF stand-off layer.
8. The method of claim 1 wherein providing the plurality of antenna structures comprises fabricating the antenna structures over the at least one redistribution layer utilizing a photolithographical patterning and metal plating process.
9. The method of claim 1 wherein the plurality of antenna structures form an antenna array, wherein the antenna array is located in a central region of the molded panel, and wherein the method further comprises producing power/ground bond pads along an outer peripheral portion of the molded panel electrically coupled to the plurality of semiconductor die.
10. The method of claim 1 wherein the at least one redistribution layer comprises a plurality of redistribution layers built to include a first ground layer electrically coupled to the antenna structures through the plurality of vertically-elongated contacts.
11. The method of claim 1 wherein the molded RF stand-off layer is formed to have a thickness of at least 70 microns.
12. A method for fabricating a microelectronic package, comprising:
producing a plurality of vertically-elongated contacts in ohmic contact with interconnect lines contained within a plurality of redistribution layers built over a molded panel containing a plurality of semiconductor die, the molded panel having a frontside at which the plurality of semiconductor die is exposed, the plurality of redistribution layers produced over the frontside of the molded panel and the plurality of semiconductor die, the plurality of redistribution layers including a first ground layer;
forming a molded radiofrequency (RF) stand-off layer over the frontside of the molded panel and on the plurality of redistribution layers such that the plurality of vertically-elongated contacts extends through the molded RF stand-off layer;
producing a second ground layer over the molded RF stand-off layer, the second ground layer substantially covering the plurality of semiconductor die as taken along an axis orthogonal to a frontside of the molded panel semiconductor die;
depositing a dielectric layer over the second ground layer; and
producing a plurality of antenna structures over the dielectric layer and over the molded RF stand-off layer, the plurality of antenna structures electrically coupled to the plurality of semiconductor die and to the first ground layer through the plurality of vertically-elongated contacts.
13. The method of claim 12 wherein producing a plurality of vertically-elongated contacts comprises:
depositing a photoimagable material over the plurality of redistribution layers;
creating via openings in the photoimagable material exposing regions of the interconnect lines; and
plating metal pillars in the via openings and over the exposed regions of the interconnect lines to produce the plurality of vertically-elongated contacts.
14. The method of claim 13 further comprising stripping the photoimagable material after plating the metal pillars, and wherein forming a molded RF stand-off layer comprises depositing the molded RF stand-off layer over the plurality of redistribution layers and around the metal pillars.
15. The method of claim 12 wherein the plurality of redistribution layers contains a last dielectric layer, and wherein the molded RF stand-off layer is formed to have a thickness at least twice the thickness of the last dielectric layer.
16. The method of claim 12 wherein the plurality of vertically-elongated contacts is produced prior to formation of the molded RF stand-off layer.
17. The method of claim 16 wherein forming a molded RF stand-off layer comprises:
depositing a mold material over the plurality of redistribution layers and the plurality of vertically-elongated contacts; and
curing the mold material to produce the molded RF stand-off layer.
18. The method of claim 12 wherein producing a plurality of vertically-elongated contacts comprises:
depositing a photoimagable material over the plurality of redistribution layers;
creating via openings in the photoimagable material exposing regions of the interconnect lines; and
plating metal pillars in the via openings and over the exposed regions of the interconnect lines to produce the plurality of vertically-elongated contacts.
19. The method of claim 12 wherein the plurality of redistribution layers has an outer dielectric layer in which openings are formed exposing regions of the interconnect lines, and wherein producing a plurality of vertically-elongated contacts comprises depositing electrically-conductive bodies in the openings and in ohmic contact with the exposed regions of the interconnect lines.
20. The method of claim 12 wherein the plurality of antenna structures form an antenna array, wherein the antenna array is located in a central region of the molded panel, and wherein the method further comprises producing power/ground bond pads along an outer peripheral portion of the molded panel electrically coupled to the plurality of semiconductor die.