MAGNETO-DIELECTRIC SUBSTRATE, CIRCUIT MATERIAL, AND ASSEMBLY HAVING THE SAME
In an embodiment, a magneto-dielectric substrate comprises a dielectric polymer matrix; and a plurality of hexaferrite particles dispersed in the dielectric polymer matrix in amount and of a type effective to provide the magneto-dielectric substrate with a magnetic constant of less than or equal to 3.5 from 500 MHz to 1 GHz, or 3 to 8 from 500 MHz to 1 GHz, and a magnetic loss of less than or equal to 0.1 from 0 to 1 GHz, or 0.001 to 0.07 over 0 to 1 GHz.
1 . A magneto-dielectric substrate, comprising:
a dielectric polymer matrix; and
a plurality of hexaferrite particles dispersed in the dielectric polymer matrix in amount and of a type effective to provide the magneto-dielectric substrate with
a magnetic constant of less than or equal to 3.5, or less than or equal to 2.5 from 500 MHz to 1 GHz, or 1 to 2 from 500 MHz to 1 GHz, and
a magnetic loss of less than or equal to 0.1 from 500 MHz to 1 GHz, or 0.001 to 0.07 over 500 MHz to 1 GHz.
2 . The magneto-dielectric substrate of claim 1 , wherein the magneto-dielectric substrate further has at least one of
a dielectric constant of 1.5 to 8 from 500 MHz to 1 GHz;
a dielectric loss of less than 0.01 or less than 0.005 over 500 MHz to 1 GHz;
a UL94 V1 rating measured at a thickness of 1.6 mm; and
a peel strength to copper of 3 to 7 pli measured in accordance with IPC test method 650, 2.4.9.
3 . The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles are present in the magneto-dielectric substrate in an amount of 5 to 60 vol %, or 10 to 50 vol %, or 15 to 45 vol %, based on the total volume of the magneto-dielectric substrate.
4 . The magneto-dielectric substrate of claim 1 , wherein the dielectric polymer matrix comprises 1,2-polybutadiene, polyisoprene, or a combination comprising at least one of the foregoing.
5 . The magneto-dielectric substrate of claim 1 , wherein the dielectric polymer matrix comprises a polybutadiene-polyisoprene copolymer, a polyetherimide, a fluoropolymer (specifically, polytetrafluoroethylene), a polyimide, polyetheretherketone, a polyamidimide, polyethylene terephthalate, polyethylene naphthalate, polycyclohexylene terephthalate, a polyphenylene ether, an allylated polyphenylene ether or a combination comprising at least one of the foregoing.
6 . The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles further comprises Sr, Ba, Co, Ni, Zn, V, Mn, or a combination comprising at least one of the foregoing.
7 . The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles comprises Mo.
8 . The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles comprises an organic polymer coating, a surfactant coating, a silane coating, or a combination comprising at least one of the foregoing coatings.
9 . The magneto-dielectric substrate of claim 1 , further comprising a fibrous reinforcing layer comprising woven or non-woven fibers.
10 . The magneto-dielectric substrate of claim 1 , wherein the magnetic constant is less than or equal to 2.5.
11 . The magneto-dielectric substrate of claim 1 , further comprising a conductive layer disposed on the magneto-dielectric substrate to form a circuit material.
12 . A method of making a magneto-dielectric substrate, the method comprising:
dispersing a plurality of hexaferrite particles in a curable polymer matrix composition to form a mixture;
forming a layer from the mixture; and
curing the curable polymer matrix composition to form the magneto-dielectric substrate;
wherein the magneto-dielectric substrate has
a magnetic constant of less than or equal to 3.5, or less than or equal to 2.5 from 500 MHz to 1 GHz, or 1 to 2 from 500 MHz to 1 GHz, and
a magnetic loss of less than or equal to 0.1 from 500 MHz to 1 GHz, or 0.001 to 0.07 over 500 MHz to 1 GHz.
13 . The method of claim 12 , further comprising impregnating a fibrous reinforcing layer with the mixture to form the layer; and
wherein the curing comprises only partially curing the polymer matrix composition of the layer to provide the magneto-dielectric substrate.
14 . The method of claim 12 , further comprising
disposing the layer on a conductive layer and curing the polymer matrix composition to form a circuit material.
15 . The method of claim 14 , wherein the curing is by laminating.
16 . The method of claim 14 , wherein the forming comprises impregnating a fibrous reinforcing layer with the mixture; and wherein the curing comprises only partially curing the polymer matrix composition of the layer to provide the magneto-dielectric substrate before disposing the magneto-dielectric substrate on the conductive layer.
17 . The method of claim 14 , further comprising patterning the conductive layer.
18 . An article comprising the magneto-dielectric substrate of claim 1 .
19 . The article of claim 18 , wherein the article is an antenna or a circuit.
20 . The article of claim 18 , wherein the article is an RF component.