Method for reducing conductive and convective heat loss from the battery in an RFID tag or other battery-powered devices

• US RE35,765 E
• Filed: 06/21/1996
• Issued: 04/07/1998
• Est. Priority Date: 06/11/1992
• Status: Expired due to Term

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Communications, Inc. (Micron Technology, Inc.)
• Inventors: Tuttle, John R.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): MERZ, EDWARD W
• Application Number:
  US08/667,415
• Time in Patent Office: 655 Days
• Field of Search: 340/825.54, 429/82, 429/96, 429/98, 429/100, 429/112, 429/120, 429/121, 429/122, 429/163, 429/185, 437/207, 437/209, 174/61, 174/62, 174/52.2, 174/52.4, 257/668, 257/676, 257/687, 257/787, 257/788, 257/792, 257/795
• US Class Current: 257/793
• CPC Class Codes: G06K 19/0702 the arrangement including a battery
• CPC Class Codes: H01L 23/20 gaseous at the normal operating temperature of the device
• CPC Class Codes: H01L 23/315 the encapsulation having a cavity
• CPC Class Codes: H01L 23/34 Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements thermal treatment apparatus H01L21/00
• CPC Class Codes: H01L 23/345 Arrangements for heating thermal treatment apparatus H01L21/00
• CPC Class Codes: H01L 23/49593 Battery in combination with a leadframe
• CPC Class Codes: H01L 23/58 Structural electrical arrangements for semiconductor devices not otherwise provided for , e.g. in combination with batteries H01L23/49593, H01L23/49596 take precedence
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

The present invention introduces a method of reducing conductive and convective heat loss from the battery unit in battery-powered devices, such as RFID tag devices. Battery heat loss prevention is accomplished by suspending the battery in a vacuum or within a low thermally conductivity gas, such as air, nitrogen, helium or argon. Further improvement is accomplished by using a minimum number of suspension points made of solid material which possesses a low thermally conductivity. The battery can be suspended by various means, the first of which totally encapsulates the battery using the minimum number of solid material suspension points mentioned above, and the second of which only a portion of the battery (such as the lower portion) is suspended in a low thermally conductive material and the upper portion is encapsulated by the low thermally conductive material fabricated in an arching structure that does not contact the upper portion of the battery. Both approaches allow suspension of the integrated circuit (IC) to be driven by the battery within the same confines of the battery by bonding the IC to the upper surface of the battery with the IC thereby residing underneath either the top solid material structure of the first approach or the arching structure of solid material of the second approach.

Claims

1. A battery powered unit comprising an integrated circuit (IC) and a battery for powering said IC wherein said IC and said battery are enclosed in a low thermally conductive material having a thermal conductivity constant less than k=10, and suspended therein by multiple pointed suspension tips comprising said low thermally conductive material.

2. The battery powered unit of claim 1 wherein said thermally conductive material is polyester.

3. The battery powered unit or claim 1 wherein said IC and said battery are separately enclosed in said thermally conductive material.

4. The battery powered unit of claim 1 wherein said IC and said battery are adjacently enclosed in said thermally conductive material.

5. The battery powered unit of claim 3 wherein said thermally conductive material arches over said IC without making direct contact.

6. The battery powered unit of claim 3 wherein said IC is attached to said battery by bonding means.

7. The battery powered unit of claim 6 wherein said bonding means comprises epoxy.

8. The battery powered unit of claim 1 wherein said suspending IC and said battery within said thermal conductive material forms areas of spacing therebetween.

9. The battery powered unit of claim 8 wherein said areas of spacing comprise a vacuum.

10. The battery powered unit of claim 8 wherein said areas of spacing comprise insulating gas.

11. The battery powered unit of claim 10 wherein said insulating gas is selected from the group consisting of argon, nitrogen, helium and air.

12. A battery powered unit comprising an integrated circuit (IC) and a battery for powering said IC wherein said IC and said battery are enclosed in a low thermally conductive material having a thermal conductivity constant less than k=10, and suspended therein by multiple pointed suspension tips comprising said low thermally conductive material;

wherein said IC is attached to said battery by a bonding means and said thermally conductive material arches over said IC without making direct contact to said IC.

13. The battery powered unit of claim 12 wherein said thermally conductive material is polyester.

14. The battery powered unit of claim 12 wherein said bonding means comprises epoxy.

15. The battery powered unit of claim 12 wherein said suspending IC and said battery within said thermal conductive material forms areas of spacing therebetween.

16. The battery powered unit of claim 15 wherein said area of spacing comprise a vacuum.

17. The battery powered unit of claim 15 wherein said areas of spacing comprise insulating gas.

18. The battery powered unit of claim 17 wherein said insulating gas is selected from the group consisting of argon, nitrogen, helium and air.

19. A radio frequency (RF) transceiver system comprising first and second sending/receiving units wherein said second sending/receiving unit comprises a communication integrated circuit (IC) and a battery for powering said communication IC wherein said IC and said battery are enclosed in a low thermally conductive material having a thermal conductivity constant less than k=10, and suspended therein by multiple pointed suspension tips comprising said low thermally conductive material.

20. The radio frequency transceiver system of claim 19 wherein said thermally conductive material is polyester.

21. The radio frequency transceiver system of claim 19 wherein said IC and said battery are separately enclosed in said thermally conductive material.

22. The radio frequency transceiver system of claim 19 wherein said IC and said battery are adjacently closed in said thermally conductive material.

23. The radio frequency transceiver system of claim 22 wherein said IC is attached to said battery by bonding means.

24. The radio frequency transceiver system of claim 23 wherein said bonding means comprises epoxy.

25. The radio frequency transceiver system of claim 19 wherein said suspending IC and said battery within said thermal conductive material forms areas of spacing therebetween.

26. The radio frequency transceiver system of claim 25 wherein said areas of spacing comprise a vacuum.

27. The radio frequency transceiver system of claim 25 wherein said areas of spacing comprise insulating gas.

28. The radio frequency transceiver system of claim 27 wherein said insulating gas is selected from the group consisting of argon, nitrogen, helium and air.

29. A radio frequency (RF) transceiver system comprising first and second sending/receiving units wherein said second sending/receiving unit comprises a communication integrated circuit (IC) and a battery for powering said communication IC wherein said IC and said battery are enclosed in a low thermally conductive material having a thermal conductivity constant less than k=10, and suspended therein by multiple pointed suspension tips comprising said low thermally conductive material;

wherein said IC is attached to said battery by a bonding means and said thermally conductive material arches over said IC without making direct contact to said IC.

30. The radio frequency transceiver system of claim 29 wherein said thermally conductive material is polyester.

31. The radio frequency transceiver system of claim 29 wherein said bonding means comprises epoxy.

32. The radio frequency transceiver system of claim 29 wherein said suspending IC and said battery within said thermal conductive material forms areas of spacing therebetween.

33. The radio frequency transceiver system of claim 32 wherein said areas of spacing comprise a vacuum.

34. The radio frequency transceiver system of claim 32 wherein said areas of spacing comprise insulating gas.

35. The radio frequency transceiver system of claim 34 wherein said insulating gas is selected from the group consisting of argon, nitrogen, helium and air. .Iadd.

37. conductive material. .Iaddend..Iadd.40. The method of claim 29, wherein the first portion of the low thermally conductive material is separate from the second portion of the low thermally conductive material. .Iaddend..Iadd.41. The method of claim 39, wherein said battery is suspended adjacent said integrated circuit in the low thermally conductive material. .Iaddend..Iadd.42. The method of claim 39, wherein the step of suspending said battery within the low thermally conductive material includes:

suspending said battery in a first portion of the low thermally conductive material; and

suspending said integrated circuit in a second portion of the low thermally conductive material, the second portion of the low thermally conductive material arching over said integrated circuit without making direct contact with the low thermally conductive material. .Iaddend..Iadd.43. The method of claim 36, further comprising the step of;

attaching said integrated circuit to said battery. .Iaddend..Iadd.44. The method of claim 43, wherein the step of attaching said integrated circuit to said battery includes bonding said integrated circuit to said battery.

36. A method of insulating a battery powered unit including an integrated circuit having a plurality of surfaces and a battery having a plurality of surfaces for powering said integrated circuit, said method comprising the steps of:

forming a low thermally conductive material to enclose said battery therein, the low thermally conductive material being formed having a plurality of suspension tips, at least one suspension tip for engaging at least one surface of said plurality of said surfaces of said battery; and

suspending said battery within the low thermally conductive material by at least one suspension tip of the plurality suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said battery. .Iaddend..Iadd.37. The method of claim 36, wherein the low thermally conductive material having a thermal conductivity constant less than k=10. .Iaddend..Iadd.38. The method of claim 36, wherein the low thermally conductive material includes polyester. .Iaddend..Iadd.39. The method of claim 36, wherein the step of suspending said battery within the low thermally conductive material includes;

suspending said battery in a first portion of the low thermally conductive material; and

suspending said integrated circuit in a second portion of the low thermally

38. Iaddend..Iadd.45. The method of claim 43, wherein the step of attaching said integrated circuit to said battery includes using epoxy to bond said integrated circuit to said battery. .Iaddend..Iadd.46. The method of claim 36, wherein the step of suspending said battery within the low thermally conductive material includes:

suspending said battery within the low thermally conductive material by at least one suspension tip of the plurality of suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said battery, the plurality of suspension tips of the low thermally conductive material forming areas of spaces therebetween. .Iaddend..Iadd.47. The method of claim 46, further comprising the step of;

evacuating the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material. .Iaddend..Iadd.48. The method of claim 46, further comprising the step of;

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material.

40. thermal conductivity constant less than k=10. .Iaddend..Iadd.52. The method of claim 50, wherein the low thermally conductive material includes polyester. .Iaddend..Iadd.53. The method of claim 50, wherein the step of attaching said integrated circuit to said battery includes using epoxy to bond said integrated circuit to said battery. .Iaddend..Iadd.54. The method of claim 50, wherein the step of suspending said battery within the low thermally conductive material includes:

suspending said battery within the low thermally conductive material by at least one suspension tip of the plurality of suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said battery, the plurality of suspension tips of the low thermally conductive material forming areas of spaces therebetween; and

suspending said integrated circuit within the low thermally conductive material by at least one suspension tip of the plurality of suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said battery, the plurality of suspension tips of the low thermally conductive material forming areas of spaces therebetween. .Iaddend..Iadd.55. The method of claim 54, further comprising the steps of;

evacuating the areas of spaces formed between the plurality of suspension

41. tips of the low thermally conductive material. .Iaddend..Iadd.56. The method of claim 54, further comprising the step of:

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material. .Iaddend..Iadd.57. The method of claim 54, further comprising the step of;

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material, insulating gas being selected from the group consisting of argon, nitrogen, helium,

42. and air. .Iaddend..Iadd.58. A method of making a radio frequency transceiver system including first and second sending/receiving units wherein said second sending/receiving unit includes a communication integrated circuit having a plurality of surfaces and a battery having a plurality of surfaces for powering said communication integrated circuit, said method comprising the steps of:

forming a low thermally conductive material to enclose said communication integrated circuit and said battery therein, the low thermally conductive material being formed having a plurality of suspension tips, at least one suspension tip for engaging at least one surface of said plurality of said surfaces of said communication integrated circuit and for engaging at least one surface of said plurality of surfaces of said battery; and

suspending said communication integrated circuit and said battery within the low thermally conductive material by at least one suspension tip of the plurality of suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said communication integrated circuit and at least one suspension tip of the plurality of suspension tips contacting at least one surface of said plurality of surfaces of said battery. .Iaddend..Iadd.59. The method of claim 58, wherein the low thermally conductive material has a thermal conductivity constant less than k=10. .Iaddend..Iadd.60. The method of claim 58, wherein the low thermally conductive material includes

43. polyester. .Iaddend..Iadd.61. The method of claim 58, wherein said communication integrated circuit is separately suspended in the low thermally conductive material from said battery in the low thermally conductive material. .Iaddend..Iadd.62. The method of claim 58, wherein said battery is suspended adjacent said communication integrated circuit in the low thermally conductive material. .Iaddend..Iadd.63. The method of claim 58, further comprising the step of:

attaching said communication integrated circuit to said battery. .Iaddend..Iadd.64. The method of claim 63, wherein the step of attaching said communication integrated circuit to said battery includes bonding said integrated circuit to said battery. .Iaddend..Iadd.65. The method of claim 63, wherein the step of attaching said communication integrated circuit to said battery includes using epoxy to bond said communication

44. integrated circuit to said battery. .Iaddend..Iadd.66. The method of claim 63, wherein the step of suspending said battery within the low thermally conductive material includes:

suspending said communication integrated circuit and said battery within the low thermally conductive material by at least one suspension tip of the plurality of suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said communication integrated circuit and at least one suspension tip of the plurality of suspension tips contacting at least one surface of said plurality of surfaces of the battery, the plurality of suspension tips of the low thermally conductive material forming areas of spaces therebetween. .Iaddend..Iadd.67. The method of claim 66, further comprising the step of;

evacuating the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material. .Iaddend..Iadd.68. The method of claim 66, further comprising the step of;

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material. .Iaddend..Iadd.69. The method of claim 66, further comprising the step of;

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material, the insulating gas being selected from the group consisting of argon,

45. nitrogen, helium and air. .Iaddend..Iadd.70. A method of making a radio frequency transceiver system including first and second sending/receiving units wherein said second sending/receiving unit includes a communication integrated circuit having a plurality of surfaces and a battery having a plurality of surfaces for powering said communication integrated circuit, said method comprising the step of:

forming a low thermally conductive material to enclose said communication integrated circuit and said battery therein, the low thermally conductive material being formed having a plurality of suspension tips for engaging at least one surface of said plurality of said surfaces of said communication integrated circuit and at least on surface of said plurality of surfaces of said battery;

bonding said communication integrated circuit to said battery; and

suspending said communication integrated circuit and said battery within the low thermally conductive material by at least one suspension tip of the plurality of suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said battery, the low thermally conductive material arching over said integrated circuit without making direct contact with the low thermally conductive material. .Iaddend..Iadd.71. The method of claim 70, wherein the low thermally conductive material has a thermal conductivity constant

46. less than k=10. .Iaddend..Iadd.72. The method of claim 70, wherein thermally conductive material includes polyester. .Iaddend..Iadd.73. The method of claim 70, wherein the step of bonding said communication integrated circuit to said battery includes using epoxy to bond said communication integrated circuit to said battery. .Iaddend..Iadd.74. The method of claim 70, wherein the step of suspending said communication integrated circuit and said battery includes:

suspending said communication integrated circuit and said battery within the low thermally conductive material by at least one suspension tip of the plurality of suspension tips of the low thermally conductive material contacting at least one surface of said plurality of surfaces of said battery, the low thermally conductive material arching over said integrated circuit without making direct contact with the low thermally conductive materials, the plurality of suspension tips of the low thermally conductive material forming areas of spaces therebetween. .Iaddend..Iadd.75. The method of claim 74, further comprising the step of;

evacuating the areas of spaces formed between the plurality of suspension

39. Iaddend..Iadd.49. The method of claim 46, further comprising the step of:

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material, the insulating gas being selected from the group consisting of argon, nitrogen, helium and air. .Iaddend..Iadd.50. A method of insulating a battery powered unit including an integrated circuit having a plurality of surfaces and a battery having a plurality of surfaces for powering said integrated circuit, said method comprising the steps of;

forming a low thermally conductive material to enclose said battery therein, the low thermally conductive material being formed having a plurality of suspension tips, at least one suspension tip for engaging at least one surface of said plurality of said surfaces of said battery;

attaching said integrated circuit to said battery by bonding said integrated circuit to said battery;

suspending said battery in a first portion of the low thermally conductive material; and

suspending said integrated circuit in a second portion of the low thermally conductive material, the second portion of the low thermally conductive material arching over said integrated circuit without making direct contact with the low thermally conductive material. .Iaddend..Iadd.51. The method of claim 50, wherein the low thermally conductive material having a

47. tips of the low thermally conductive material. .Iaddend..Iadd.76. The method of claim 75, further comprising the step of:

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material. .Iaddend..Iadd.77. The method of claim 75, further comprising the step of;

placing insulating gas in the areas of spaces formed between the plurality of suspension tips of the low thermally conductive material, the insulating gas being selected from the group consisting of argon, nitrogen, helium and air. .Iaddend.