Passive thermal solution for hand-held devices
The present invention relates to a thermal solution for hand-held devices. In an embodiment, the present invention implements a thermal gap filler and a system enclosure for effective thermal management of high performance hand-held devices. In an embodiment, a hand-held device of the present invention increases the thermal power dissipation capability by reducing its system thermal resistance.
This application is a continuation of U.S. patent application Ser. No. 11/268,979, now U.S. Pat. No. 7,595,468, filed Nov. 7, 2005 and issued Sep. 29, 2009.
BACKGROUND OF THE INVENTIONCurrently, hand-held products such as cell phones and PDA's are equipped with features to provide multiple modes of communication, organization, storage, etc.
Additional features boost power consumption, which increases the challenge of thermal solutions for hand-held devices subject to ever-increasing size constraints. As a result, package and system power densities increase leading to significant temperature elevation. This may also lead to performance deterioration, package delamination, and reliability issues.
The disclosed embodiments will be better understood from a reading of the following detailed description, taken in conjunction with the accompanying figures in the drawings in which:
In an embodiment, the present invention includes a passive thermal solution for hand-held devices. In an embodiment, the passive thermal solution may comprise a gap filler and a thermally conductive casing to dissipate heat produced by mechanical and/or electronic components in the hand-held device. In an embodiment, the gap filler used in the hand-held device is a thermal gap filler. In an embodiment, the thermal conductivity of the thermally conductive casing may be approximately 2.0 W/m-K or greater.
In an embodiment, the operation of hand-held device 101 produces heat. The production of heat within hand-held device 101 can have a detrimental effect on the functionality of the embedded components. In an embodiment of the present invention, heat may dissipate to an ambient exterior to hand-held device 101 via conduction through thermal gap filler 110 and thermally conductive casing 120.
In an embodiment of the present invention, thermal gap filler 110 may be positioned between a portion of thermally conductive casing 120 and electronic package 100. In an embodiment, thermal gap filler 110 passively facilitates heat transfer from electronic package 100 to thermally conductive casing 120. In an embodiment, thermal gap filler 110 comprises acrylate resin. In an embodiment when thermal gap filler 110 comprises an acrylate resin, the thermal conductivity of thermal gap filler 110 is approximately 1 W/m-K. In an embodiment when thermal gap filler comprises silicone, the thermal conductivity of thermal gap filler 110 is approximately 10 W/m-K. In an embodiment, thermal gap filler 110 may have a thermal conductivity in the range of 1 W/m-K to 10 W/m-K. In another embodiment, the thermal gap filler 110 may have a thermal conductivity in a range between about 5 W/m-K to about 15 W/m-K. In other embodiments, the thermal gap 110 filler may have a different thermal conductivity.
In an embodiment, a thermal gap filler 110 with a thermal conductivity of at least 1 W/m-K may sufficiently facilitate heat transfer to thermally conductive casing 120. In this embodiment, thermal gap filler 110 transfers heat to thermally conductive casing 120 well. In an embodiment when the temperature of electronic package 100 is greater than the temperature of thermal gap filler 110, heat is transferred from electronic package 100 to thermal gap filler 110. In an embodiment, thermal gap filler 110 acts as a heat conduit from which heat produced from electronic package 100 is transferred to thermally conductive casing 120 through thermal gap filler 110.
In an embodiment of the present invention, thermally conductive casing 120 may serve as the system enclosure to fully or partially enclose the embedded components of hand-held device 101 as illustrated in
In an embodiment, thermally conductive casing 120 with a thermal conductivity of at least 2.0 W/m-K is sufficient to transfer heat to an ambient outside of hand-held device 101. In an embodiment, the temperature of thermal gap filler 110 is greater than the temperature of thermally conductive casing 120 such that heat is transferred from thermal gap filler 110 to thermally conductive casing 120. In an embodiment, heat is transferred from thermal gap filler 110 to a thermally conductive casing 120 and is subsequently transferred to an ambient outside of hand-held device 101.
In an embodiment, an electronic package 100 may provide all or part of the electronic functionality of hand-held device 101. In an embodiment when electronic package 100 is a microprocessor and is active, heat 130 is conducted through thermal gap filler 110 throughout the inner area of hand-held device 101. In
In yet another embodiment of the present invention, a thermal gap filler may partially fill the volume of thermally conductive casing 120. In an embodiment, a thermal gap filler may fill more of the volume of thermally conductive casing 120 than filled by thermal gap filler 110 in
In an embodiment of the present invention, a heat spreader may be incorporated in the hand-held device. In an embodiment, a heat spreader may be incorporated to increase the thermal dissipation capabilities of hand-held devices.
In an embodiment as illustrated in
In an embodiment of the present invention, the hand-held device may incorporate an EMI shield. In an embodiment as illustrated in
In an embodiment, the hand-held device of the present invention may exhibit better heat dissipation ability than hand-held devices currently in the art.
Chart 500 of
In an embodiment as illustrated in
In an embodiment as illustrated in chart 600 of
In an embodiment, the hand-held device of the present invention may be manufactured such that the hand-held device of the present invention features a thermally conductive casing with a thermal conductivity greater than 2.0 W/m-K, an electronic package embedded inside the thermally conductive casing, and a thermal gap filler positioned between the thermally conductive casing and the electronic package. In an embodiment, the hand-held device may be manufactured such that the thermal gap filler provides a heat path from the electronic package to the thermally conductive casing. In an embodiment, the heat path created by the thermal gap filler is substantially free from air gaps. In yet another embodiment, the hand-held device of the present invention may be manufactured such that the thermal gap filler substantially fills the volume enclosed by said thermally conductive casing not filled by other components within said thermally conductive casing.
Claims
1. A device comprising:
- a casing;
- an electronic package at least partially enclosed in the casing; and
- a gap filler adjacent to the electronic package,
- wherein: the device has EMI shielding properties.
2. The device of claim 1 further comprising:
- a heat spreader adjacent to the gap filler.
3. The device of claim 1 wherein:
- the casing is a thermally conductive casing.
4. The device of claim 3 wherein:
- the thermally conductive casing comprises a material selected from the group consisting of polyphenylene sulfide, liquid crystalline polymer, magnesium, polyphenylene sulfide, polypropylene, thermoplastic elastomer, polyamide, and polybutene terephthalate.
5. The device of claim 3 wherein:
- a thermal conductivity of the thermally conductive casing is greater than approximately 2 W/m-K.
6. The device of claim 5 wherein:
- the thermal conductivity of the thermally conductive casing is in a range from 2 W/m-K to 20 W/m-K.
7. The device of claim 5 wherein:
- the gap filler provides a heat path from the electronic package to the thermally conductive casing, wherein the heat path is substantially free of air gaps.
8. The device of claim 1 wherein:
- the gap filler comprises a material selected from the group consisting of acrylate resin and silicone.
9. The device of claim 1 wherein:
- a thermal conductivity of the gap filler is greater than about 1 W/m-K.
10. The device of claim 1 wherein:
- the gap filler substantially fills a volume enclosed by the casing not filled by other components within the casing.
11. The device of claim 1 wherein:
- the device is a hand-held, portable device.
12. The device of claim 1 further comprising:
- an EMI shield within the casing,
- wherein: the EMI shielding properties are provided by the EMI shield; and a thermal conductivity of the EMI shield is greater than 150 W/m-K.
13. A thermally-enhanced shielding solution comprising:
- a casing;
- an electronic package at least partially enclosed in the casing;
- an EMI shield adjacent to the electronic package; and
- a thermal gap filler between the EMI shield and the electronic package,
- wherein: a thermal conductivity of the thermal gap filler is greater than about 1 W/m-K; the thermal gap filler provides a heat path from the electronic package to the casing; and
- the heat path is substantially free of air gaps such that the thermal gap filler substantially fills a volume enclosed by the casing not filled by other components within the casing.
14. The thermally-enhanced shielding solution of claim 13 further comprising:
- a heat spreader adjacent to the thermal gap filler.
15. The thermally-enhanced shielding solution of claim 13 wherein:
- the casing comprises a material selected from the group consisting of polyphenylene sulfide, liquid crystalline polymer, magnesium, polyphenylene sulfide, polypropylene, thermoplastic elastomer, polyamide, and polybutene terephthalate; and
- the gap filler comprises a material selected from the group consisting of acrylate resin and silicone.
16. A device comprising:
- a casing;
- an electronic package at least partially enclosed in the casing;
- a gap filler adjacent to the casing; and
- a heat spreader adjacent to the gap filler,
- wherein: a space between the electronic package and the casing has EMI shielding properties.
17. The device of claim 16 further comprising:
- an EMI shield in the space between the electronic package and the casing.
18. The device of claim 17 wherein:
- the EMI shield has a thermal conductivity greater than 150 W/m-K.
19. The device of claim 18 wherein:
- the EMI shield has a thermal conductivity in a range between 150 W/m-K and 400 W/m-K.
20. The device of claim 17 wherein:
- the EMI shield is disposed between a first portion and a second portion of the gap filler.
Type: Application
Filed: Sep 15, 2009
Publication Date: Jan 14, 2010
Inventors: Sung-won Moon (Phoenix, AZ), Suzana Prsitic (Chandler, AZ), Todd Young (Gilbert, AZ)
Application Number: 12/586,065
International Classification: H05K 7/20 (20060101); H05K 9/00 (20060101);