[go: up one dir, main page]

WO2013074920A1 - Low thermal impedance interface for an led bulb - Google Patents

Low thermal impedance interface for an led bulb Download PDF

Info

Publication number
WO2013074920A1
WO2013074920A1 PCT/US2012/065511 US2012065511W WO2013074920A1 WO 2013074920 A1 WO2013074920 A1 WO 2013074920A1 US 2012065511 W US2012065511 W US 2012065511W WO 2013074920 A1 WO2013074920 A1 WO 2013074920A1
Authority
WO
WIPO (PCT)
Prior art keywords
heatsink
shell
thermal interface
light bulb
led light
Prior art date
Application number
PCT/US2012/065511
Other languages
French (fr)
Inventor
Ronald J. Lenk
Carol Lenk
Original Assignee
Reliabulb, Llc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Reliabulb, Llc filed Critical Reliabulb, Llc
Publication of WO2013074920A1 publication Critical patent/WO2013074920A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/50—Cooling arrangements
    • F21V29/70—Cooling arrangements characterised by passive heat-dissipating elements, e.g. heat-sinks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
    • F21V29/85—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems characterised by the material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
    • F21K9/00—Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
    • F21K9/20—Light sources comprising attachment means
    • F21K9/23—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings
    • F21K9/232—Retrofit light sources for lighting devices with a single fitting for each light source, e.g. for substitution of incandescent lamps with bayonet or threaded fittings specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V3/00—Globes; Bowls; Cover glasses
    • F21V3/04—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings
    • F21V3/06—Globes; Bowls; Cover glasses characterised by materials, surface treatments or coatings characterised by the material
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2101/00—Point-like light sources
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21Y—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00—Light-generating elements of semiconductor light sources
    • F21Y2115/10—Light-emitting diodes [LED]

Definitions

  • the present invention relates to a thermal interface between an interior heatsink and the shell of a light-emitting diode (LED) light bulb.
  • LED light-emitting diode
  • LED light bulbs typically require some sort of heatsink to remove the waste heat generated by the LEDs they use. In order to conform to the traditional incandescent light bulb shape, these heatsinks need to be inside the light bulb's shell. However, this presents some challenges in getting the heat out, which LED light bulbs to date have not been able to overcome.
  • a typical heatsink material is a metal such as aluminum.
  • a typical shell material might be glass or a plastic.
  • the LEDs produce heat
  • the heatsink rises in temperature and expands.
  • the shell would be in direct contact with the heatsink, so as to maximize the ability of the LED light bulb to get its waste heat to its outer surface.
  • the shell material typically expands more than does the heatsink. This causes the shell material to separate from the heatsink, raising the thermal impedance from the LEDs to the outer surface, contrary to what is needed for efficient removal of waste heat.
  • the present disclosure is directed to an LED light bulb that uses an elastic, thermally conductive material as an interface between an interior heatsink and the shell of the light bulb.
  • the thermal conductivity of the material ensures that it does not add substantial thermal impedance to the thermal path from the LEDs to the outer surface of the light bulb.
  • the material may have high conformability, allowing it to conform to the surface of the shell. Alternatively, the material may be cut or have cut-outs to conform to the surface of the shell.
  • the material also has high compressibility, allowing it to be squeezed between the heatsink and the shell when these are close together.
  • the elasticity of the material ensures that it expands back to its original conformation as the separation between the heatsink and the shell increases.
  • the thermal impedance of the material should remain relatively low even when it is in a state of low compression.
  • the material is electrically insulating, providing a barrier between the outer surface of the light bulb and the electrically live circuitry inside.
  • FIG. 1 is a cross-sectional drawing of an LED light bulb showing the interior heatsink, shell and interface material at room temperature according to one or more embodiments shown or described herein.
  • FIG. 2 is a cross-sectional drawing of an LED light bulb showing the interior heatsink, shell and interface material at elevated temperature according to one or more embodiments shown or described herein.
  • Fig. 3 is a drawing of the interface material showing conformation-aiding cuts and cut-outs according to one or more embodiments shown or described herein.
  • FIG. 1 is a cross-sectional drawing of an LED light bulb 100 showing the interior heatsink 110, shell 120 and interface material 130 at room temperature. As shown in FIG. 1, at this temperature the interface material 130 is compressed to a thickness 140. It is in direct contact with both the heatsink 110 and the shell 120, providing a low thermal impedance path between the heatsink 110 and the shell 120.
  • FIG. 2 is a cross-sectional drawing of an LED light bulb 100 showing the interior heatsink 110, shell 120 and interface material 130 at elevated temperature.
  • the shell 120 has expanded more than the heatsink 110.
  • the interface material 130 has expanded to a thickness 141 to accommodate this increased separation between the shell 120 and the heatsink 110. It remains in direct contact with both the heatsink 110 and the shell 120, continuing to provide a low thermal impedance path between the heatsink 110 and the shell 120.
  • the interface material 130 may be repeatedly cycled between its more and less compressed states without degradation to its other properties.
  • Fig. 3 is a drawing of the interface material 130 showing conformation-aiding cuts 150 and cut-outs 151.
  • the interface material 130 is shaped as a section of an annulus, so that it can fit around the increasing circumference of the shell 120 towards the bottom.
  • cuts 150 are introduced at the bottom of the interface material 130. These cuts 150 provide a means for the interface material 130 to spread out around the larger bottom of the shell 120 without significantly compromising the thermal contact area between the heatsink 110 and the shell 120.
  • cut-outs 151 are introduced near the top of the annulus. These cut-outs 151 provide a means for the interface material 130 to pull-in around the smaller top of the shell 120 without significantly compromising the thermal contact area between the heatsink 110 and the shell 120.
  • the cut-outs 151 are shown here as diamonds, but other shapes may be used to accomplish the same function. It will be apparent to those skilled in the art that various modifications and variation can be made to the structure of the present disclosure without departing from the scope or spirit of the embodiments disclosed herein. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of the embodiments provided they fall within the scope of the following claims and their equivalents.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Non-Portable Lighting Devices Or Systems Thereof (AREA)

Abstract

An LED light bulb thermal interface comprises a heatsink internal to said LED light bulb, a shell for said LED light bulb, a thermal interface between said internal heatsink and said shell, and wherein said thermal interface material is compressible.

Description

LOW THERMAL IMPEDANCE INTERFACE FOR AN LED BULB
TECHNICAL FIELD
The present invention relates to a thermal interface between an interior heatsink and the shell of a light-emitting diode (LED) light bulb.
BACKGROUND ART
LED light bulbs typically require some sort of heatsink to remove the waste heat generated by the LEDs they use. In order to conform to the traditional incandescent light bulb shape, these heatsinks need to be inside the light bulb's shell. However, this presents some challenges in getting the heat out, which LED light bulbs to date have not been able to overcome.
One of the challenges lies in the mismatch in thermal expansion between the heatsink material and the shell material. A typical heatsink material is a metal such as aluminum. A typical shell material might be glass or a plastic. As the LEDs produce heat, the heatsink rises in temperature and expands. Ideally, the shell would be in direct contact with the heatsink, so as to maximize the ability of the LED light bulb to get its waste heat to its outer surface. However, the shell material typically expands more than does the heatsink. This causes the shell material to separate from the heatsink, raising the thermal impedance from the LEDs to the outer surface, contrary to what is needed for efficient removal of waste heat.
It would be desirable to be able to ensure the low-thermal impedance interface over temperature between the interior heatsink and the shell of the LED light bulb despite differences in thermal expansion between the two.
SUMMARY OF INVENTION
The present disclosure is directed to an LED light bulb that uses an elastic, thermally conductive material as an interface between an interior heatsink and the shell of the light bulb. The thermal conductivity of the material ensures that it does not add substantial thermal impedance to the thermal path from the LEDs to the outer surface of the light bulb. The material may have high conformability, allowing it to conform to the surface of the shell. Alternatively, the material may be cut or have cut-outs to conform to the surface of the shell. The material also has high compressibility, allowing it to be squeezed between the heatsink and the shell when these are close together. The elasticity of the material ensures that it expands back to its original conformation as the separation between the heatsink and the shell increases. The thermal impedance of the material should remain relatively low even when it is in a state of low compression.
In a preferred embodiment, the material is electrically insulating, providing a barrier between the outer surface of the light bulb and the electrically live circuitry inside.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings are included to provide a further understanding of the present disclosure, and is incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments of the present disclosure and, together with the detailed description, serve to explain the principles of the present disclosure.
FIG. 1 is a cross-sectional drawing of an LED light bulb showing the interior heatsink, shell and interface material at room temperature according to one or more embodiments shown or described herein.
FIG. 2 is a cross-sectional drawing of an LED light bulb showing the interior heatsink, shell and interface material at elevated temperature according to one or more embodiments shown or described herein.
Fig. 3 is a drawing of the interface material showing conformation-aiding cuts and cut-outs according to one or more embodiments shown or described herein.
DESCRIPTION OF EMBODIMENTS
Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. According to the design characteristics, a detailed description of the preferred embodiment is given below.
FIG. 1 is a cross-sectional drawing of an LED light bulb 100 showing the interior heatsink 110, shell 120 and interface material 130 at room temperature. As shown in FIG. 1, at this temperature the interface material 130 is compressed to a thickness 140. It is in direct contact with both the heatsink 110 and the shell 120, providing a low thermal impedance path between the heatsink 110 and the shell 120.
FIG. 2 is a cross-sectional drawing of an LED light bulb 100 showing the interior heatsink 110, shell 120 and interface material 130 at elevated temperature. As shown in FIG. 2, at this temperature the shell 120 has expanded more than the heatsink 110. The interface material 130 has expanded to a thickness 141 to accommodate this increased separation between the shell 120 and the heatsink 110. It remains in direct contact with both the heatsink 110 and the shell 120, continuing to provide a low thermal impedance path between the heatsink 110 and the shell 120. The interface material 130 may be repeatedly cycled between its more and less compressed states without degradation to its other properties.
Fig. 3 is a drawing of the interface material 130 showing conformation-aiding cuts 150 and cut-outs 151. As shown in FIG. 3, the interface material 130 is shaped as a section of an annulus, so that it can fit around the increasing circumference of the shell 120 towards the bottom. In a preferred embodiment, in order to avoid either crowding on top or stretching on bottom of the interface material 130 of the annulus, cuts 150 are introduced at the bottom of the interface material 130. These cuts 150 provide a means for the interface material 130 to spread out around the larger bottom of the shell 120 without significantly compromising the thermal contact area between the heatsink 110 and the shell 120.
In another embodiment, cut-outs 151, are introduced near the top of the annulus. These cut-outs 151 provide a means for the interface material 130 to pull-in around the smaller top of the shell 120 without significantly compromising the thermal contact area between the heatsink 110 and the shell 120. The cut-outs 151 are shown here as diamonds, but other shapes may be used to accomplish the same function. It will be apparent to those skilled in the art that various modifications and variation can be made to the structure of the present disclosure without departing from the scope or spirit of the embodiments disclosed herein. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of the embodiments provided they fall within the scope of the following claims and their equivalents.

Claims

1. An LED light bulb thermal interface, comprising:
a heatsink internal to said LED light bulb;
a shell for said LED light bulb;
a thermal interface material between said internal heatsink and said shell; and wherein said thermal interface material is compressible.
2. An LED light bulb thermal interface as set forth in Claim 1, wherein said thermal interface material is in a state of high compression when said heatsink is cold, and in a state of low compression when said heatsink is hot.
3. An LED light bulb thermal interface as set forth in Claim 1, wherein said thermal interface material remains low thermal resistance both when compressed and when decompressed.
4. An LED light bulb thermal interface as set forth in Claim 1, wherein said thermal interface material is elastic.
5. An LED light bulb thermal interface as set forth in Claim 1, wherein said thermal interface material is viscoelastic.
6. An LED light bulb thermal interface as set forth in Claim 1, wherein said thermal interface material is cut or has cut-outs to conform to said shell and/or internal heatsink.
PCT/US2012/065511 2011-11-17 2012-11-16 Low thermal impedance interface for an led bulb WO2013074920A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201161560851P 2011-11-17 2011-11-17
US61/560,851 2011-11-17

Publications (1)

Publication Number Publication Date
WO2013074920A1 true WO2013074920A1 (en) 2013-05-23

Family

ID=48430187

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2012/065511 WO2013074920A1 (en) 2011-11-17 2012-11-16 Low thermal impedance interface for an led bulb

Country Status (1)

Country Link
WO (1) WO2013074920A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10068830B2 (en) 2014-02-13 2018-09-04 Honeywell International Inc. Compressible thermal interface materials
US10781349B2 (en) 2016-03-08 2020-09-22 Honeywell International Inc. Thermal interface material including crosslinker and multiple fillers
US11041103B2 (en) 2017-09-08 2021-06-22 Honeywell International Inc. Silicone-free thermal gel
US11072706B2 (en) 2018-02-15 2021-07-27 Honeywell International Inc. Gel-type thermal interface material
US11373921B2 (en) 2019-04-23 2022-06-28 Honeywell International Inc. Gel-type thermal interface material with low pre-curing viscosity and elastic properties post-curing

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004349216A (en) * 2003-05-26 2004-12-09 Toshiba Lighting & Technology Corp Light bulb fluorescent lamps and lighting equipment
JP2006024544A (en) * 2004-06-09 2006-01-26 Toshiba Lighting & Technology Corp Light bulb-type fluorescent lamp and lighting fixture
US20070058377A1 (en) * 2005-09-15 2007-03-15 Zampini Thomas L Ii Interconnection arrangement having mortise and tenon connection features
JP2011014270A (en) * 2009-06-30 2011-01-20 Stanley Electric Co Ltd Lamp
US20110044043A1 (en) * 2009-08-21 2011-02-24 Shwin-Chung Wong Led lamp
KR20110085922A (en) * 2010-01-19 2011-07-27 명범영 LED lighting fixtures and lighting devices using the same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004349216A (en) * 2003-05-26 2004-12-09 Toshiba Lighting & Technology Corp Light bulb fluorescent lamps and lighting equipment
JP2006024544A (en) * 2004-06-09 2006-01-26 Toshiba Lighting & Technology Corp Light bulb-type fluorescent lamp and lighting fixture
US20070058377A1 (en) * 2005-09-15 2007-03-15 Zampini Thomas L Ii Interconnection arrangement having mortise and tenon connection features
JP2011014270A (en) * 2009-06-30 2011-01-20 Stanley Electric Co Ltd Lamp
US20110044043A1 (en) * 2009-08-21 2011-02-24 Shwin-Chung Wong Led lamp
KR20110085922A (en) * 2010-01-19 2011-07-27 명범영 LED lighting fixtures and lighting devices using the same

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10068830B2 (en) 2014-02-13 2018-09-04 Honeywell International Inc. Compressible thermal interface materials
US10781349B2 (en) 2016-03-08 2020-09-22 Honeywell International Inc. Thermal interface material including crosslinker and multiple fillers
US11041103B2 (en) 2017-09-08 2021-06-22 Honeywell International Inc. Silicone-free thermal gel
US11072706B2 (en) 2018-02-15 2021-07-27 Honeywell International Inc. Gel-type thermal interface material
US11373921B2 (en) 2019-04-23 2022-06-28 Honeywell International Inc. Gel-type thermal interface material with low pre-curing viscosity and elastic properties post-curing

Similar Documents

Publication Publication Date Title
WO2013074920A1 (en) Low thermal impedance interface for an led bulb
US8421320B2 (en) LED light bulb equipped with light transparent shell fastening structure
US8398260B2 (en) Heat-dissipation structure of LED lamp
MY165672A (en) Lightweight heat sinks and led lamps employing same
US9989238B2 (en) Low light failure, high power led street lamp and method for manufacturing the same
JP2011091037A5 (en)
GB0419467D0 (en) LED light source
US20110198068A1 (en) Heat dissipation structure having combined cooling fins
CA2541181A1 (en) Lamp string
WO2008105428A1 (en) Light-emitting device
CN203594979U (en) Electric light bulb
KR200450690Y1 (en) Built-in AC LED built-in light that can change the lighting direction
WO2012080916A1 (en) An illumination apparatus and a method of assembling the illumination apparatus
US9920915B2 (en) Lighting device and luminaire
EP3273160A1 (en) Heat-dissipation lamp cup
US20170268765A1 (en) Lamp capable of isolating heat source
WO2010114244A3 (en) Led lamp
JP2006260986A (en) Recessed ceiling lighting fixture
CN204062609U (en) Lamp device and lighting device
CN105276532B (en) A kind of adapter assembly and the illuminator with the adapter assembly
TW201116769A (en) Structure of LED lamp
US20130044492A1 (en) Led lamp
TWM501529U (en) Heat dissipation device of LED
KR101551459B1 (en) Florescent type light emitting diode lamp
US20130051036A1 (en) Led lamp

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12848824

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12848824

Country of ref document: EP

Kind code of ref document: A1