Low-dielectric constant, low-dissipation factor laminates including aerogel layers
A laminate comprises one or more electrically-conductive layers and one or more electrically-insulative layers coupled to the electrically-conductive layer(s). Each of the electrically-conductive layer(s) can comprise at least 90% by weight of copper. Each of the electrically-insulative layer(s) can comprise a layer of polymeric aerogel. For at least one of opposing front and back surfaces of the laminate, at least a portion of the surface is defined by one of the electrically-conductive layer(s).
1. A laminate comprising:
at least two electrically-conductive layers comprising a first electrically-conductive layer and a second-electrically conductive layer, wherein the first electrically-conductive layer and the second electrically-conductive layer each comprise at least 90% by weight of copper; and
at least two electrically-insulative layers comprising a first electrically-insulative layer and a second electrically-insulative layer, wherein the first and second electrically-insulative layers are coupled by one or more adhesive layers to the first electrically-conductive layer and the second electrically-conductive layer, respectively; wherein the first electrically-insulative layer is coupled to the second electrically-insulative layer by an additional adhesive layer, and wherein the first and second electrically-insulative layers each comprise an organic polymeric aerogel,
wherein at least a portion of a front surface of the laminate is defined by the first electrically-conductive layer; and
wherein at least a portion of a back surface of the laminate is defined by the second electrically-conductive layer.
2. The laminate of claim 1 , wherein at least one of the electrically-conductive layer(s) has a thickness that is between 0.5 mils and 0.9 mils.
3. The laminate of claim 1 , wherein at least one of the electrically-conductive layer(s) has an area density of between 0.35 and 0.75 oz/ft 2 ounces per square foot (oz/ft 2 ).
4. The laminate of claim 1 , wherein at least one of the organic polymeric aerogels comprises micropores, mesopores, and/or macropores.
5. The laminate of claim 4 , wherein at least one of:
the organic polymeric aerogels has a pore volume; and
at least 10% of the pore volume is made up of macropores.
6. The laminate of claim 4 , wherein at least one:
the organic polymeric aerogels has a pore volume; and
at least 10% of the pore volume is made up of micropores and/or mesopores.
7. The laminate of claim 1 , wherein at least one of the organic polymeric aerogels has an average pore diameter that is between 100 nm and 800 nm.
8. The laminate of claim 1 , wherein at least one of the polymeric aerogels comprises at least 90% by weight of the organic polymer.
9. The laminate of claim 1 , wherein at least one of the organic polymeric aerogels comprises at least 90% by weight of polyimide.
10. The laminate of claim 1 , wherein at least one of the organic polymeric aerogel has a thickness that is between 3.0 mils and 7.0 mils.
11. The laminate of claim 1 , wherein at least one of the organic polymeric aerogel is a polyimide aerogel having a decomposition temperature that is greater than or equal to 400° C.
12. The laminate of claim 1 , wherein at least one of the adhesive layer(s) or the additional adhesive layer comprises a fluoropolymer film.
13. The laminate of claim 1 , wherein at least one of the adhesive layer(s) or the additional adhesive layer comprises a polyimide film.
14. The laminate of claim 1 , wherein at least one of the adhesive layer(s) or the additional adhesive layer comprises a B-stage epoxy.
15. The laminate of claim 1 , wherein at least one of the adhesive layer(s) between the electrically-conductive layer(s) and the electrically-insulating layer(s) has a dielectric constant at 10 GHz that is less than or equal to 3.5, a dissipation factor at 10 GHz that is less than or equal to 0.0040, a decomposition temperature that is greater than or equal to 350° C., and a melting point that is greater than or equal to 100° C.
16. The laminate of claim 1 , wherein at least one of the adhesive layer(s) or the additional adhesive layer has a thickness that is between 0.75 and 1.25 mils.
17. The laminate of claim 1 , wherein the laminate has a thickness that is between 5.0 mils and 30 mils.
18. The laminate of claim 1 , wherein the laminate is disposed in a roll such that a portion of the front surface of the laminate faces a portion of the back surface of the laminate.
19. The laminate of claim 1 , wherein the laminate has a dielectric constant, at 10 GHz, that is less than or equal to 2.0.
20. The laminate of claim 1 , wherein the laminate has a dissipation factor, at 10 GHz, that is less than or equal to 0.0025.
21. The laminate of claim 1 , wherein:
the laminate comprises one or more reinforcing layers, wherein:
each of the reinforcing layer(s) has a flexural rigidity that is at least 10% larger than a flexural rigidity of each of the electrically-conductive layer(s) and the electrically-insulative layer(s);
for at least one of the electrically-insulative layer(s), at least one of the reinforcing layer(s) is at least partially embedded in the layer of the organic polymeric aerogel such that the Young's modulus of the electrically-insulative layer is at least 200 MPa; and
for at least one of the electrically-insulative layer(s), a plurality of fibers are dispersed in the layer of the organic polymeric aerogel such that the Young's modulus of the electrically-insulative layer is at least 200 MPa.
22. The laminate of claim 21 , wherein at least one of the reinforcing layer(s) comprises one or more unidirectional, woven, or nonwoven sheets that comprise fibers and/or one or more paper sheets.
23. The laminate of claim 1 , wherein the laminate does not comprise fibers.
24. A circuit board comprising:
the laminate of claim 1 ; and
for at least one of the front and back surfaces, a solder mask layer bonded to the surface such that the solder mask layer covers at least a majority of the surface, the solder mask layer comprising at least 90% by weight of polymer.
25. The circuit board of claim 24 , wherein a thickness of the solder mask layer is less than or equal to 3.2 mils.
26. An apparatus comprising the circuit board of claim 24 , wherein:
the apparatus comprises an antenna electrically coupled to the circuit board; and/or
the apparatus is an electrical amplifier, a radar system, or a communication system.