Electronic device thermal management system
An electronic device has a heat source and a generally rectangular shape battery proximate the heat source. The battery may have first and second major surfaces. A thermal regulator is in thermal contact with both of the heat source and substantially all of at least the first major surface of the battery. During operation of the device, heat transferred from the heat source to the first major surface via the thermal regulator balances the temperature profile exhibited along the first major surface such that it is substantially uniform.
1. An electronic device comprising:
a. a heat source wherein the heat source consists of at least one of a central processing unit, a graphical processing unit, a drive chip, a memory chip, a radio frequency (RF) power amplifier, an RF transceiver, a DC/DC switcher, a Power Management Integrated Circuit, a buck and/or boost inductor, a power converter, a wireless charging element, a high speed digital electronics, a cameras image processing and stabilizing element, a still or video image lighting source, a display element, a display element driver, a disk drive a high-speed USB port, and a high-power application port,
b. a generally rectangular shaped battery proximate the heat source
i. the battery having first and second major surfaces extending between oppositely disposed terminal ends, and
c. a thermal regulator comprising at least one of a sheet of compressed particles of exfoliated graphite particles, a graphitized polyimide sheet and a combination thereof in thermal contact with both of the heat source and substantially all of the first major surface of the battery,
whereby, during operation of the device, heat is transferred from the heat source to the first major surface via the thermal regulator and a temperature profile of the first major surface being substantially uniform.
2. The electronic device of claim 1 further comprising a near field communication element proximate one of the major surfaces of the battery and between the terminal ends.
3. The electronic device of claim 1 further comprising the thermal regulator in thermal contact with substantially all of the second major surface of the battery, whereby during operation of the device, heat transferred from the heat source to the second major surface via the thermal regulator and a temperature profile of the second major surface being substantially uniform.
4. The electronic device of claim 3 wherein a thickness of a portion of the thermal regulator in thermal contact with the second major surface comprises no more than half of the thickness of a second portion of the thermal regulator in thermal contact with the first major surface of the battery.
5. The electronic device of claim 4 wherein an anisotropic ratio of the in-plane conductivity to the through-plane conductivity of the portion of the thermal regulator in thermal contact with the second major surface comprises no more than 60:1.
6. The electronic device of claim 4 wherein a thickness of the portion comprises no more than 0.50 mm and a thickness of the second portion comprises up to 1.0 mm.
7. The electronic device of claim 1 further comprising an EMI shield proximate the first the major surface of the battery and the first major surface located opposed to the exterior back surface of the device.
8. The electronic device of claim 1 further comprising an EMI shield around a majority of an exterior of the battery.
9. The electronic device of claim 1 wherein the thermal regulator comprises one of more sheets of compressed particles of exfoliated graphite particles.
10. The electronic device of claim 9 wherein the sheet doped with a frequency attenuating material.
11. The electronic device of claim 1 wherein the sheet includes one or more EMI shield additives.
12. The electronic device of claim 1 further comprising a thermal interface material disposed between a surface of the heat source and the thermal regulator.
13. The electronic device of claim 1 further comprising a second heat source in thermal contact with the thermal regulator.
14. The electronic device of claim 1 further comprising an EMI shield around any portion of the battery that generates an EMI concern.
15. The electronic device of claim 11 wherein the additive includes permalloy mu metal.
16. The electronic device of claim 11 wherein the additive includes at least one of nickel, silver, tin, steel, stainless steel, gold, aluminum, and alloys thereof.
17. The electronic device of claim 1 wherein the thermal contact occurs by conduction.
18. The electronic device of claim 1 wherein the near field communication element is disposed outside of the thermal regulator such that the thermal regulator is disposed between the near field communication element and the battery.
19. The electronic device of claim 1 wherein the near field communication element is disposed inside of the thermal regulator such that the near field communication element is disposed between the thermal regulator and the battery.
20. The electronic device of claim 1 further comprising an EMI shield consisting of a first sheet of metal proximate the first major surface of the battery and a second sheet of metal disposed around a majority of an exterior of the battery.