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 6,376,922 B1
• Filed: 03/15/2000
• Issued: 04/23/2002
• 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:
  US09/525,567
• Time in Patent Office: 769 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
• 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 microelectronic device comprising:

providing integrated circuitry supported by a substrate;

providing a liquid resin having an organic polymer filler material therein, wherein the organic polymer filler material is solid as provided within the liquid resin and wherein the organic polymer filler material comprises a polymer powder;

applying the resin having the organic polymer filler material over at least a portion of the substrate and integrated circuitry; and

curing the applied resin into a solid mass.

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

3. The method of claim 1, wherein the organic polymer filler material includes at least one of the following:

polytetrafluoroethylene, fluorinated ethylene propylene, polypropylene, polystyrene, and polybutylene.

4. The method of claim 1, wherein the liquid resin includes at least one of the following:

epoxy, urethane, acrylic, polyester, and silicone.

5. The method of claim 1, wherein the liquid resin comprises between about 10% and 90% by volume of the organic polymer filler material.

6. The method of claim 1, wherein the liquid resin comprises between about 40% and 70% by volume of the organic polymer filler material.

7. The method of claim 1, wherein the curing of the applied resin is conducted at a temperature less than or equal to 120°

C.

8. The method of claim 1, further comprising:

providing an antenna on the substrate; and

operably connecting the antenna and the integrated circuitry to provide a device configured for RF operation.

9. A method of forming a microelectronic device comprising:

providing a liquid encapsulating material having a first RF-associated dissipation factor;

mixing a filler material having a second RF-associated dissipation factor which is less than the first RF-associated dissipation factor into the liquid encapsulating material to provide a liquid mixture having an effective RF-associated dissipation factor which is less than the first RF-associated dissipation factor;

applying the liquid mixture over a substrate having microelectronic circuitry configured for RF operation thereon; and

curing the liquid mixture into a solid coating.

10. The method of claim 9, wherein the filler material having the second RF-associated dissipation factor comprises a solid.

11. The method of claim 9, wherein the liquid encapsulating material comprises an epoxy.

12. The method of claim 11, wherein the liquid encapsulating material comprises a hardener.

13. The method of claim 9, wherein the filler material having the second RF-associated dissipation factor comprises an organic polymer powder.

14. The method of claim 13, wherein the organic polymer powder comprises polytetrafluoroethylene.

15. The method of claim 9, wherein the applying of the liquid mixture comprises covering the microelectronic circuitry therewith.

16. A method of forming a microelectronic radio frequency communication device comprising:

providing integrated circuitry and an antenna operably connected therewith and configured to transmit and receive radio frequency signals;

providing a liquid polymer resin having a first radio frequency dissipation factor and an organic polymer powder therewithin having a second radio frequency dissipation factor which is less than the first radio frequency dissipation factor;

coating at least a portion of the antenna and the integrated circuitry with the liquid polymer resin having the polymer powder therewithin; and

curing the coated liquid polymer resin having the polymer powder to form a solid coating having a radio frequency dissipation factor which is less than the first radio frequency dissipation factor.

17. The method of claim 16, wherein the coating comprises coating the entire antenna with the liquid polymer resin having the polymer powder therewithin.

18. The method of claim 16, wherein the providing of the integrated circuitry and the antenna comprises:

printing conductive antenna-forming material on a substrate; and

mounting an integrated circuitry chip on the substrate.

19. The method of claim 18, wherein the coating comprises coating the entire antenna with the liquid polymer resin having the polymer powder therewithin.

20. The method of claim 16, wherein the liquid polymer resin comprises an epoxy.

21. The method of claim 16, wherein the polymer powder comprises polytetrafluoroethylene.

22. The method of claim 16, wherein the liquid polymer resin and the polymer powder comprise a liquid mixture having, before the curing, between about 10% to 90% by volume of the polymer powder.

23. The method of claim 16, wherein the liquid polymer resin and the polymer powder comprise a liquid mixture having, before cure, between about 40% to 70% by volume of the polymer powder.

24. The method of claim 16, wherein the curing comprises curing the coated liquid polymer resin having the polymer powder at a temperature of less than or equal to 120 C.

25. A method of forming a microelectronic radio frequency communication device comprising:

supporting a semiconductor chip, at least one antenna, and a battery relative to a common substrate;

the chip, antenna, and battery being operably interconnected and configured to operate relative to at least one desired radio frequency;

forming a flowable mixture comprising a resin and at least one organic polymer filler material suspended therewithin, the one filler material being frequency-transmissive to a desired degree relative to said at least one desired radio frequency; and

forming the flowable mixture over at least a portion of the device and thereafter exposing the flowable mixture to conditions which are effective to harden the flowable mixture into a solid coating thereover.

26. The method of claim 25, wherein the at least one desired frequency comprises a frequency in a range between 1 GHz and 30 GHz.

27. The method of claim 25, wherein the at least one desired frequency is about 2.45 GHz.

28. The method of claim 25, wherein the at least one organic polymer filler material comprises a polymer powder.

29. The method of claim 28, wherein the polymer powder comprises polytetrafluoroethylene.

30. The method of claim 28, wherein the resin comprises an epoxy.

31. The method of claim 28, wherein the forming of the flowable mixture comprises forming the mixture over the entire antenna.

32. The method of claim 28, wherein the forming of the flowable mixture comprises forming the mixture over the entire device.

33. A method of forming a microelectronic communication device comprising:

supporting a semiconductor chip relative to a substrate;

supporting an antenna relative to the substrate, the antenna being operably connected with the chip and configured therewith to operate relative to at least one desired radio frequency; and

covering the chip and substrate with a rigidified coating of material having a plurality of organic polymeric particles suspended therewithin, said particles imparting a degree of frequency transmissivity to the coating relative to said at least one desired radio frequency which is higher than the coating would have without said organic polymer particles.

34. The method of claim 33, further comprising:

prior to the covering of the chip and substrate, forming a liquid mixture comprising the organic polymeric particles; and

wherein the covering of the chip and substrate comprises curing the liquid mixture over the chip and substrate.

35. A microelectronic radio frequency communication device comprising:

a substrate;

a semiconductor chip supported by the substrate;

at least one antenna supported by the substrate and operably connected with the semiconductor chip, the antenna and the chip configured to operate relative to a desired radio frequency;

a battery supported by the substrate and operably connected with the semiconductor chip; and

a solid coating of material disposed over the antenna, the solid coating material comprising a cured resin material and an organic polymer material dispersed within the cured resin material.

36. The microelectronic radio frequency communication device of claim 35, wherein the organic polymer material comprises a polymer powder.

37. The microelectronic radio frequency communication device of claim 35, wherein the organic polymer material comprises polytetrafluoroethylene.

38. The microelectronic radio frequency communication device of claim 35, wherein the solid coating is disposed over the entire substrate and effectively seals the semiconductor chip, the antenna, and the battery relative to the substrate.

39. The microelectronic radio frequency communication device of claim 35, the solid coating having a higher degree of frequency transmissivity relative to the desired radio frequency than the solid coating would have without the organic polymer material dispersed therein.