Fluoropolymer dielectric composition for use in circuitized substrates and circuitized substrate including same
A dielectric composition for forming a dielectric layer usable in circuitized substrates such as PCBs, chip carriers and the like, the composition including at least two fluoropolymers and two inorganic fillers. A circuitized substrate including at least one such dielectric layer and at least one conductive layer thereon is also provided.
1. A dielectric composition adapted for forming a dielectric layer for use in circuitized substrates, said dielectric composition comprising:
first and second fluoropolymers, said first fluoropolymer having a high melting point from 300 degrees Celsius to 350 degrees Celsius and said second fluoropolymer having a low melting point from 200 degrees Celsius to 280 degrees Celsius; and
first and second inorganic fillers, said first inorganic filler having a high thermal conductivity from 600 W/m.K degrees to 2000 W/m.K degrees and said inorganic second filler having a low thermal conductivity from 5 W/m.K degrees to 400 W/m.K degrees, said dielectric layer including said dielectric composition having a dielectric constant of from about 2.8 to about 3.6.
2. The dielectric composition of claim 1 wherein said first and second inorganic fillers include particles having a size no greater than about 10 microns.
3. The dielectric composition of claim 2 wherein said particles are of spherical configuration.
4. The dielectric composition of claim 2 wherein said first and second inorganic fillers are selected from the group consisting of alumina, aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, boron nitride, diamond powder, titanium oxide, silica, ceramic and combinations thereof.
5. The dielectric composition of claim 4 wherein said first and second inorganic fillers are silica, said silica selected from the group consisting of spherical amorphous silica, semi-spherical amorphous silica, hollow silica microspheres and combinations thereof.
6. The dielectric composition of claim 1 wherein said first and second fluoropolymers belong to the polytetrafluoroethylene family and comprise from about 50 to about 90 percent by weight of said composition and said first and second fillers comprise from about 10 to about 50 percent by weight of said composition.
7. The invention of claim 1 wherein said dielectric layer further includes supporting material.
8. The invention of claim 7 wherein said supporting material comprises fiber-glass cloth.
9. The dielectric composition of claim 1 further including a third fluoropolymer having a melting point lower than said high and low melting points of said first and second fluoropolymers, respectively.
10. A circuitized substrate comprising:
at least one dielectric layer including a dielectric composition having first and second fluoropolymers, said first fluoropolymer having a high melting point from 300 degrees Celsius to 350 degrees Celsius and said second fluoropolymer having a low melting point from 200 degrees Celsius to 280 degrees Celsius and first and second inorganic fillers, said first inorganic filler having a high thermal conductivity from 600 W/m.K degrees to 2000 W/m.K degrees and said inorganic second filler having a low thermal conductivity from 5 W/m.K degrees to 400 W/m.K degrees, said dielectric layer including said dielectric composition having a dielectric constant of from about 2.8 to about 3.6; and
at least one conductive layer positioned on said at least one dielectric layer.
11. The circuitized substrate of claim 10 wherein said at least one conductive layer is comprised of copper or copper alloy.
12. The circuitized substrate of claim 10 wherein said first and second inorganic fillers include particles having a size no greater than about 10 microns.
13. The circuitized substrate of claim 12 wherein said particles are of spherical configuration.
14. The circuitized substrate of claim 12 wherein said first and second inorganic fillers are selected from the group consisting of alumina, aluminum oxide, aluminum nitride, silicon nitride, silicon carbide, boron nitride, diamond powder, titanium oxide, silica, ceramic and combinations thereof.
15. The circuitized substrate of claim 14 wherein said first and second inorganic fillers are silica, said silica selected from the group consisting of spherical amorphous silica, semi-spherical amorphous silica, hollow silica microspheres and combinations thereof.
16. The circuitized substrate of claim 10 wherein said first and second fluoropolymers belong to the polytetrafluoroethylene family and comprise from about 50 to about 90 percent by weight of said composition and said first and second fillers comprise from about 10 to about 50 percent by weight of said composition.
17. The circuitized substrate of claim 10 wherein said at least one dielectric layer further includes supporting material.
18. The circuitized substrate of claim 17 wherein said supporting material comprises fiber-glass cloth.
19. The circuitized substrate of claim 10 wherein said dielectric composition further includes a third fluoropolymer having a melting point lower than said high and low melting points of said first and second fluoropolymers, respectively.