RADIO FREQUENCY-TRANSMISSIVE COMPOSITIONS, METHODS OF FORMING RADIO FREQUENCY-TRANSMISSIVE COMPOSITIONS, MICROELECTRONIC DEVICES, WIRELESS RADIO FREQUENCY COMMUNICATION DEVICES, AND METHODS OF FORMING MICROELECTRONIC DEVICES, WIRELESS RADIO FREQUENCY COMMUNICATION DEVICES

• US 6,522,023 B2
• Filed: 04/20/2001
• Issued: 02/18/2003
• 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:
  US09/839,550
• Publication Number:
  US 20010031630A1
• Time in Patent Office: 669 Days
• Field of Search: 438/106, 438/125, 438/126, 438/127, 438/758, 427/96, 427/385.5, 257/789, 257/787, 257/793, 257/795, 455/347
• US Class Current: 257/789
• 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 identification device comprising:

providing a circuit comprising a radio frequency receiver and transmitter;

operably connecting an antenna with the circuit, the antenna being configured to receive and transmit at least one desired radio frequency; and

coating the antenna and at least some of the circuit with a coating material comprising a resin having solid polymeric material therewithin, the resin having a first radio frequency transmissivity value and the polymeric material imparting a second radio frequency transmissivity value to the coating material which is greater than the first radio frequency transmissivity value.

2. The method of claim 1, wherein the solid polymeric material comprises an organic powder.

3. The method of claim 1, wherein the solid polymeric material comprises powdered polytetrafluoroethylene.

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

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

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

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

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

12. The method of claim 1, wherein the solid polymeric material comprises fluorinated ethylene propylene.

13. The method of claim 1, wherein the solid polymeric material comprises polypropylene.

14. The method of claim 1, wherein the solid polymeric material comprises polystyrene.

15. The method of claim 1, wherein the solid polymeric, material comprises polybutylene.

16. The method of claim 1, wherein the resin composition comprises between about 10% to 90% by volume of the solid polymeric material.

17. The method of claim 1, wherein the resin composition comprises between about 40% to 70% by volume of the solid polymeric material.

18. The method of claim 1, wherein the coating comprises coating the entire circuit with the coating material.

19. The method of claim 1, wherein the at least one desired frequency comprises a frequency in a range between 1 GHz and 30 Ghz.

20. The method of claim 1, wherein the at least one desired frequency is about 2.45 Ghz.

4. A radio frequency microelectronic device comprising:

a substrate;

integrated circuitry supported by the substrate and configured for radio frequency operation; and

a solid mass disposed over the substrate and at least a portion of the integrated circuitry, the solid mass comprising a hardened resin composition having a suspension of organic polymer filler material dispersed therewithin, the solid mass having an RF dissipation factor lower than the solid mass would have absent the organic polymer filler material dispersed therewithin.

5. The radio frequency microelectronic device of claim 4 further comprising an antenna disposed over the substrate, the solid mass being disposed over the antenna.

6. The radio frequency microelectronic device of claims 4, wherein the organic polymer filler material comprises polytetrafluoroethylene.

21. The device of claim 4, wherein the resin comprises epoxy.

22. The device of claim 4, wherein the resin comprises urethane.

23. The device of claim 4, wherein the resin comprises acrylic.

24. The device of claim 4, wherein the resin comprises polyester.

25. The device of claim 4, wherein the resin comprises silicone.

26. The device of claim 4, wherein the filler material comprises fluorinated ethylene propylene.

27. The device of claim 4, wherein the filler material comprises polypropylene.

28. The device of claim 4, wherein the filler material comprises polystyrene.

29. The device of claim 4, wherein the filler material comprises polybutylene.

30. The device of claim 4, wherein the resin composition comprises between about 10% to 90% by volume of the filler material.

31. The device of claim 4, wherein the resin composition comprises between about 40% to 70% by volume of the filler material.

32. The device of claim 4, wherein the frequency operation is at at least one desired frequency in a range between 1 GHz and 30 Ghz.

33. The device of claim 4, wherein the frequency operation is at about 2.45 Ghz.