Thermal distribution assembly in an electronic device

Patent metadata

Field	Value
Publication number	US-10244659-B2
Application number	US-201715712069-A
Country	US
Kind code	B2
Filing date	Sep 21, 2017
Priority date	Sep 22, 2016
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A thermal distribution assembly for an electronic device is disclosed. The electronic device includes an enclosure defined by a metal band and a non-metal bottom wall formed by glass, sapphire, or plastic. In this regard, the enclosure may include a relatively low thermal conductivity. However, the thermal distribution assembly provides heat transfer capabilities that offset thermal conductivity losses by using a non-metal bottom wall, and also provides added structural support. The thermal distribution assembly may include a first layer, a second layer, and a third layer. The first and third layers provide structural support, while the second layer provides a relatively high thermally conductive layer. The thermal distribution assembly includes sidewalls engaging and thermally coupling to the metal band, allowing the thermal distribution assembly to draw heat from a heat-generating component, and pass the heat to the metal band while minimizing or preventing temperature increases along the non-metal bottom wall.

First claim

What is claimed is:

1. A portable electronic device, comprising:
a back wall and sidewalls that, in cooperation with the back wall, define a cavity that carries components, wherein the back wall includes a material having a first thermal conductivity and wherein the sidewalls includes a material having a second thermal conductivity greater than the first thermal conductivity such that the sidewalls have a greater ability to conduct thermal energy than does the back wall, wherein the components include:
a heat-generating component that is capable of generating heat,
a thermal distribution assembly capable of directing at least some of heat generated by the heat-generating component away from the back wall and towards the sidewalls, the thermal distribution assembly comprising:
a first layer having a first contact surface in direct thermal contact with the heat-generating component, the first layer comprising a material having a first heat transfer characteristic that promotes a heat flow from the heat-generating component in a direction away from and generally perpendicular to the first contact surface,
a second layer having a second contact surface at least a portion of which is in direct thermal contact with the first layer, the second layer comprising a material having a second heat transfer characteristic that promotes the heat flow in a direction generally parallel to the second contact surface, the second heat transfer characteristic different from the first heat transfer characteristic, and
a third layer having a third contact surface in direct thermal contact with the second layer and a sidewall contact surface of at least one of the sidewalls such that the heat flow from the second layer flows generally perpendicular to and away from the second contact surface to the sidewall contact surface such that the sidewalls act as a distributed heat sink thereby preventing heat trapping in the back wall and avoiding formation of a thermal hot spot.

2. The portable electronic device of claim 1 , wherein:
the first layer is formed from a first type material, and
the second layer formed from a second type material different from the first type material.

3. The portable electronic device of claim 2 , wherein the first type material includes stainless steel, and wherein the second type material includes copper.

4. The portable electronic device of claim 2 , wherein the second type material comprises graphite.

5. The portable electronic device of claim 4 , further comprising:
a first weld formed on the first layer to secure the graphite with the first layer; and
a second weld formed on the third layer to secure the graphite with the third layer.

6. The portable electronic device of claim 1 , wherein the sidewalls include a metal band, and wherein the back wall includes a transparent protective layer coupled with the metal band.

7. The portable electronic device of claim 1 , further comprising a channel formed in the first layer, the channel adapted to receive a component.

8. An electronic device, comprising:
a band formed from a metal, the band including a first sidewall component and a second sidewall component;
a protective layer formed from a transparent material and secured with the band, wherein the band and the protective layer define an internal volume;
a heat-generating component disposed in the internal volume; and
a thermal distribution assembly disposed in the internal volume and thermally coupled to the heat-generating component, the thermal distribution assembly engaging the first sidewall component and the second sidewall component, the thermal distribution assembly comprising:
a first layer having a first heat transfer characteristic that promotes a heat flow from the heat-generating component in a direction away from and generally perpendicular to a first contact surface in thermal contact with the heat-generating component,
a second layer having a second heat transfer characteristic that promotes the heat flow in a direction generally parallel to a second contact surface in direct thermal contact with the first layer, the second heat transfer characteristic different from the first heat transfer characteristic,
wherein the heat flow from the second layer to at least one of the first sidewall component and the second sidewall component flows generally perpendicular to and away from the second contact surface to the at least one of the first sidewall component and the second sidewall component.

9. The electronic device of claim 8 , wherein
the first layer is formed from a first type material; and
the second layer is formed from a second type material different from the first type material.

10. The electronic device of claim 9 , wherein the thermal distribution assembly comprises:
a first sidewall engaging the first sidewall of the band; and
a second sidewall engaging the second sidewall of the band.

11. The electronic device of claim 10 , further comprising a second protective layer, wherein the thermal distribution assembly is positioned between the heat-generating component and the second protective layer.

12. The electronic device of claim 9 , wherein the second layer comprises graphite.

13. The electronic device of claim 12 , further comprising:
a first weld formed on the first layer to secure the graphite with the first layer; and
a second weld formed on a third layer to secure the graphite with the third layer.

14. The electronic device of claim 8 , wherein the thermal distribution assembly is positioned between the heat-generating component and the protective layer.

15. A method for making a thermal distribution assembly for removing heat from a heat-generating component in an electronic device having an enclosure sidewall, the method comprising:
securing a first layer with a second layer, the first layer including a first bottom wall and a first sidewall extending from the first bottom wall, the second layer including a second bottom wall engaging the first bottom wall, the second layer further including a second sidewall extending from the second bottom wall and engaging the first sidewall; and
securing a third layer with the second layer, the third layer including a third bottom wall engaging the second bottom wall, the third layer further including a third sidewall extending from the third bottom wall and engaging the second sidewall and the enclosure sidewall, wherein the first layer distributes heat from the heat-generating component to the second layer, and wherein the heat passes from the second layer through the third sidewall to the enclosure sidewall.

16. The method of claim 15 , wherein securing the first layer with the second layer comprising forming the first layer with a first type material and forming the second layer with a second type material different from the first type material.

17. The method of claim 15 , wherein securing the second layer with the first layer and the third layer comprises embedding the second layer between the first layer and the second layer such that the second layer is fully covered by the first layer and the third layer.

18. The method of claim 15 , further comprising:
forming a channel in the first layer; and
a removing a portion of the second layer in a location corresponding to the channel.

19. The method of claim 15 , wherein:
the second layer comprises graphite,
securing the first layer with the graphite comprises welding the first layer, and
securing the third layer with the graphite comprises welding the third layer.

Assignees

• Apple Inc

Inventors

• Jarvis Daniel W
• Pakula David A
• Dunsmoor David J
• Spraggs Ian A
• Hooton Lee E
• Rammah Marwan
• Hill Matthew D
• Meyer Robert F
• Bertin James A
• Bennett Eric M
• Helmore Simon C
• Wah Melissa A
• Housour Jon F
• Fournier Douglas G
• Tomasetta Christopher S

Classifications

• H02J7/70

  characterised by the mechanical construction · CPC title

• G06F2203/04112

  Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material · CPC title

• H05K1/0216

  Reduction of cross-talk, noise or electromagnetic interference (grounding H05K1/0215) · CPC title

• H05K1/148

  Arrangements of two or more hingeably connected rigid printed circuit boards, i.e. connected by flexible means · CPC title

• H05K2201/042

  Stacked spaced PCBs; Planar parts of folded flexible circuits having mounted components in between or spaced from each other · CPC title