Radio frequency-transmissive compositions, methods of forming radio frequency-transmissive compositions

• US 6,114,447 A
• Filed: 08/14/1997
• Issued: 09/05/2000
• Est. Priority Date: 08/14/1997
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Lake, Rickie C.
• Primary Examiner(s): Dawson, Robert
• Assistant Examiner(s): Robertson, Jeffrey B.
• Application Number:
  US08/911,309
• Time in Patent Office: 1,118 Days
• Field of Search: 525/107, 525/123, 525/222, 525/165, 525/105, 525/106, 525/104
• US Class Current: 525/104
• CPC Class Codes: C08L 101/12 characterised by physical features, e.g. anisotropy, viscosity or electrical conductivity liquid crystal materials or compositions C09K19/00

Abstract

Radio frequency-transmissive compositions having reduced dissipation factors, microelectronic devices, and in particular, wireless radio frequency communication devices which utilize such compositions, and methods of forming the same are described. In one implementation, a liquid resin is provided and a solid organic polymer filler material is provided within the resin to impart a degree of radio frequency transmissivity which is greater than that of the resin alone, i.e. the composition has a reduced dissipation factor. An exemplary resin comprises epoxy and an exemplary filler material is a polytetrafluoroethylene powder. In another implementation, such composition is formed or applied over a substrate which includes an antenna formed thereon and cured to provide a solid coating. The substrate can also have integrated circuitry and a battery mounted thereon to provide a wireless communication device. In such a case, the composition can be formed over and cured atop the integrated circuitry and the battery.

Claims

1. A method of forming a radio-frequency-transmissive composition having a reduced radio frequency dissipation factor comprising:

providing a liquid resin and encapsulating material having a first radio frequency dissipation factor; and

mixing an organic polymer filler material with the liquid resin and encapsulating material to form a resin composition having a second radio frequency dissipation factor which is less than the first radio frequency dissipation factor.

2. The method of claim 1, wherein the organic polymer filler material is a solid.

3. The method of claim 1, wherein the liquid resin comprises epoxy.

4. The method of claim 1, wherein the liquid resin comprises urethane.

5. The method of claim 1, wherein the liquid resin comprises acrylic.

6. The method of claim 1, wherein the liquid resin comprises polyester.

7. The method of claim 1, wherein the liquid resin comprises silicone.

8. The method of claim 1, wherein the organic polymer filler material comprises a polymer powder.

9. The method of claim 1, wherein the organic polymer filler material comprises polytetrafluoroethylene.

10. The method of claim 1, wherein the organic polymer filler material comprises fluorinated ethylene propylene.

11. The method of claim 1, wherein the organic polymer filler material comprises polypropylene.

12. The method of claim 1, wherein the organic polymer filler material comprises polystyrene.

13. The method of claim 1, wherein the organic polymer filler material comprises polybutylene.

14. The method of claim 1, wherein the resin composition comprises between about 10% to 90% by volume of the organic polymer filler material.

15. The method of claim 1, wherein the resin composition comprises between about 40% to 70% by volume of the organic polymer filler material.

16. The method of claim 1 further comprising curing the resin composition into a solidified mass.

17. A radio-frequency-transmissive composition comprising:

a liquid resin and encapsulating material having a first radio frequency dissipation factor; and

a solid organic polymer filler material disposed within the liquid resin and encapsulating material to form a resin composition having a second radio frequency dissipation factor which is less than the first radio frequency dissipation factor.

18. The radio-frequency-transmissive composition of claim 17, wherein the organic polymer filler material comprises a polymer powder.

19. The radio-frequency-transmissive composition of claim 17, wherein the resin composition is radio frequency transmissive to a greater degree that the liquid resin.