Densified foam for thermal insulation in electronic devices
地域：
CA
CA Pleasanton
摘要
A heat spreading and insulating material using densified foam is provided that has a heat spreading layer that is adhered to an insulating layer. The material is designed to be used with mobile devices that generate heat adjacent to heat sensitive components. The insulating layer is formed from a compressed layer of polyimide foam to increase its density. The polyimide foam retains a significant amount of insulating properties through the densification process. In some embodiments, an EMI shielding layer is added to improve electrical properties of the device. The heat spreading layer may be a graphite material with heat conducting properties that preferentially conduct heat in-plane but can also be metal foil or other isotropic heat conducting material. The material may also include pressure sensitive layers to permanently apply the material to the mobile device.
說明書
This application claims the benefit of U.S. Utility application Ser. No. 15/357,800, filed Nov. 11, 2016, which claims the benefit of U.S. Provisional Application No. 62/257,307, filed Nov. 19, 2015, the disclosures of which are hereby incorporated by reference.
As products across multiple market segments incorporate electronics with increasing processing power, the processors & components within those electronics are generating higher levels of point-source heat, potentially damaging nearby sensitive components within the products. Further, hot spots and generally the heat are objectionable to users as they handle the devices. Current technology employs heat “spreaders” as a means to prevent heat from generating hot spots within devices. These are typically a very thin layer of heat-resistant material (which is also heat conductive) placed inside the device, covering as much of the device footprint as possible. The spreader overlays and absorbs point source heat and conducts (spreads) it across its surface area, reducing “hot spots.” A heat spreader that is more effective in both absorbing and moving heat as well as isolating sensitive components is needed.
權(quán)利要求
What is claimed is:1. A heat spreading and insulating material for use with a mobile device having heat generating components and heat sensitive components, said material comprising:a unitary thermal insulating layer formed from a densified sheet of polyimide open cell foam, said densified sheet having a first density between 25-60 kg/m3, said densified sheet having an outwardly facing surface and an oppositely located inwardly facing surface, said outwardly facing surface being spaced from said inwardly facing surface to define a first thickness; said unitary thermal insulating layer having further densified areas where said insulating layer is further densified to have a density greater than said first density, said outwardly facing surface is spaced from said inwardly facing surface to define a second thickness in said further densified areas, said second thickness in said further densified areas being smaller than said first thickness; a first adhesive layer having a first adhesive surface and an oppositely located second adhesive surface, said inwardly facing surface of said insulating layer adheredly contacting said first adhesive surface, said first adhesive layer conforming to said inwardly facing surface; a heat spreading layer formed from a material that conducts heat and having an adhesive facing surface and an oppositely located component facing surface, said adhesive facing surface separated from said component facing surface to define a thickness, said adhesive facing surface adheredly contacting said second adhesive surface of said first adhesive layer, said heat spreading layer conforming to said second adhesive surface; and an electrically insulating layer adhered to said component facing surface of said heat spreading layer. 2. The heat spreading material of claim 1 , when said heat spreading layer is adjacent said heat generating components, heat from said heat generating components preferentially transfers along said thickness of said heat spreading layer. 3. The heat spreading material of claim 1 , wherein said electrically insulating layer has an exposed adhesive surface to form a second pressure sensitive adhesive layer, said second pressure sensitive adhesive layer in contact with said heat generating components. 4. The heat spreading material of claim 3 , wherein said second pressure sensitive adhesive layer has gaps in said exposed adhesive surface. 5. The heat spreading material of claim 1 , when said heat spreading layer contacts said heat generating components, heat from said heat generating components preferentially transfers along said thickness of said heat spreading layer. 6. A heat spreading and insulating material for use with a mobile device having heat generating components and heat sensitive components, said material comprising:a unitary thermal insulating layer formed from a densified sheet of polyimide open cell foam, said densified sheet having a first density between 25-60 kg/m3, said densified sheet having an outwardly facing surface and an oppositely located inwardly facing surface, said outwardly facing surface being spaced from said inwardly facing surface to define a first thickness; said unitary thermal insulating layer having further densified areas where said insulating layer is further densified to have a density greater than said first density, said outwardly facing surface is spaced from said inwardly facing surface to define a second thickness in said further densified areas, said second thickness in said further densified areas being smaller than said first thickness; a first adhesive layer having a first adhesive surface and an oppositely located second adhesive surface, said inwardly facing surface of said insulating layer adheredly contacting said first adhesive surface, said first adhesive layer conforming to said inwardly facing surface; and a heat spreading layer formed from a material that conducts heat and having an adhesive facing surface and an oppositely located component facing surface, said adhesive facing surface separated from said component facing surface to define a thickness, said adhesive facing surface adheredly contacting said second adhesive surface of said first adhesive layer, said heat spreading layer conforming to said second adhesive surface. 7. The heat spreading material of claim 6 , further comprising an electrically insulating layer adhered to said component facing surface of said heat spreading layer. 8. The heat spreading material of claim 7 , wherein said second pressure sensitive adhesive layer is in contact with said heat generating components. 9. The heat spreading material of claim 7 , when said heat spreading layer is adjacent said heat generating components, heat from said heat generating components preferentially transfers along said thickness of said heat spreading layer. 10. The heat spreading material of claim 7 , wherein said electrically insulating layer has an exposed adhesive surface to form a second pressure sensitive adhesive layer. 11. The heat spreading material of claim 10 , wherein said electrically insulating layer has gaps in said exposed adhesive surface.
意見反饋
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