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

• US 5,323,150 A
• Filed: 06/11/1992
• Issued: 06/21/1994
• Est. Priority Date: 06/11/1992
• Status: Expired

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Tuttle, John R.
• Primary Examiner(s): Yusko, Donald J.
• Assistant Examiner(s): GIUST, JOHN
• Application Number:
  US07/897,224
• Time in Patent Office: 740 Days
• Field of Search: 429/96, 429/98, 429/100, 429/112, 429/120, 429/121, 429/122, 429/163, 429/185, 429/82, 437/209, 437/207, 174/61, 174/62, 174/52.2, 174/52.4, 257/668, 257/676, 257/687, 257/787, 257/788, 257/792, 257/795, 340/825.54
• 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 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 of 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 enclosed 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.