Magneto-dielectric substrate, circuit material, and assembly having the same

Patent metadata

Field	Value
Publication number	US-9596755-B2
Application number	US-201514882967-A
Country	US
Kind code	B2
Filing date	Oct 14, 2015
Priority date	Oct 15, 2014
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

In an embodiment, a magneto-dielectric substrate comprises a dielectric polymer matrix; and a plurality of hexaferrite particles dispersed in the polymer matrix in an amount and of a type effective to provide a magneto-dielectric substrate having a magnetic constant of greater than or equal to 2.5 from 0 to 500 MHz, or 3 to 8 from 0 to 500 MHz; a magnetic loss of less than or equal to 0.1 from 0 to 500 MHz, or 0.001 to 0.05 over 0 to 500 MHz; and a dielectric constant of 1.5 to 8 or 2.5 to 8 from 0 to 500 MHz.

First claim

We claim:

1. A magneto-dielectric substrate, comprising:
a thermoset polymer matrix comprising a polybutadiene, a polyisoprene, a polyimide, or a combination comprising at least one of the foregoing; and
a plurality of hexaferrite particles dispersed in the polymer matrix in an amount and of a type effective to provide the magneto-dielectric substrate having
a magnetic constant of greater than or equal to 2.5 from 0 to 500 MHz, or 3 to 8 from 0 to 500 MHz,
a magnetic loss of less than or equal to 0.1 from 0 to 500 MHz, or 0.001 to 0.05 over 0 to 500 MHz
a dielectric constant of 1.5 to 8 or 2.5 to 8 from 0 to 500 MHz;
a ratio of the dielectric constant to the magnetic constant of 1 to 2; and
a peel strength to copper of 3 to 7 pli measured in accordance with IPC test method 650, 2.4.9.

2. The magneto-dielectric substrate of claim 1 , wherein the magneto-dielectric substrate further has at least one of
a dielectric loss of less than 0.01 or less than 0.005 over 0 to 500 MHz; and
a UL94 V1 rating measured at a thickness of 1.6 mm; and
the magnetic constant is 2.5 to 3.1.

3. The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles is 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 polymer matrix comprises the polybutadiene and/or the polyisoprene;
optionally an ethylene-propylene liquid rubber having a weight average molecular weight of less than or equal to 50,000 g/mol as measured by gel permeation chromatography based on polycarbonate standards;
optionally, a dielectric filler; and
optionally, a flame retardant.

5. The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles comprises Sr, Ba, Co, Ni, Zn, V, Mn, or a combination comprising one or more of the foregoing.

6. The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles comprises Ba and Co.

7. The magneto-dielectric substrate of claim 1 , wherein the plurality of hexaferrite particles comprises a silane coating.

8. The magneto-dielectric substrate of claim 1 , further comprising a fibrous reinforcing layer comprising woven or non-woven fibers.

9. The magneto-dielectric substrate of claim 8 , wherein the fibers comprise glass fibers, ferrite fibers, ferrite alloy fibers, cobalt fibers, cobalt alloy fibers, iron fibers, iron alloy fibers, nickel fibers, nickel alloy fibers, polymer fibers comprising particulate ferrite, a particulate ferrite alloy, particulate cobalt, a particulate cobalt alloy, particulate iron, a particulate iron alloy, particulate nickel, a particulate nickel alloy, or a combination comprising at least one of the foregoing.

10. A method of making the magneto-dielectric substrate of claim 1 , the method comprising
dispersing the plurality of hexaferrite particles in a curable polymer matrix composition to form a dispersed composition;
forming a layer from the dispersed composition; and
curing the curable polymer matrix composition to form the magneto-dielectric substrate.

11. The method of claim 10 , further comprising impregnating a fibrous reinforcing layer with the dispersed composition; and
partially curing the polymer matrix composition of the layer to provide a prepreg.

12. The magneto-dielectric substrate of claim 1 , further comprising
a conductive layer disposed on the magneto-dielectric substrate.

13. The method of claim 10 , the method further comprising
disposing the layer on the conductive layer; and then
curing the curable polymer matrix composition.

14. The method of claim 13 , wherein the curing is by laminating.

15. The method of claim 13 , wherein the forming comprises impregnating a fibrous reinforcing layer with the dispersed composition; and partially curing the curable polymer matrix composition to provide a prepreg before disposing the prepreg on the conductive layer.

16. The method of claim 13 , further comprising patterning the conductive layer.

17. An article comprising the magneto-dielectric substrate of claim 1 .

18. The article of claim 17 ; wherein the magneto-dielectric substrate further comprises a conductive layer; and wherein the article is a circuit material or an antenna comprising the circuit material.

19. The article of claim 17 ; wherein the article is an RF component.

Assignees

• Rogers Corp

Inventors

• Sethumadhavan Murali
• Horn Iii Allen F
• Sprentall Karl Edward
• White Michael

Classifications

• H05K2201/083

  Magnetic materials · CPC title

• H01F17/0006

  Printed inductances (printed coils for dynamo-electric machines H02K3/26; printed circuits H05K) · CPC title

• H05K3/4644

  by building the multilayer layer by layer, i.e. build-up multilayer circuits (making via holes in the insulating layers H05K3/0011; special circuit boards as base or core whereon the multilayer is built H05K3/4602) · CPC title

• D06M15/227

  of hydrocarbons, or reaction products thereof, e.g. afterhalogenated or sulfochlorinated · CPC title

• H05K3/061

  Etching masks · CPC title