US20120024579A1 - Bendable circuit structure for led mounting and interconnection - Google Patents
Bendable circuit structure for led mounting and interconnection Download PDFInfo
- Publication number
- US20120024579A1 US20120024579A1 US13/269,148 US201113269148A US2012024579A1 US 20120024579 A1 US20120024579 A1 US 20120024579A1 US 201113269148 A US201113269148 A US 201113269148A US 2012024579 A1 US2012024579 A1 US 2012024579A1
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- Prior art keywords
- circuit structure
- led
- led mounting
- interconnection
- laminate
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- 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
- F21V21/00—Supporting, suspending, or attaching arrangements for lighting devices; Hand grips
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/03—Use of materials for the substrate
- H05K1/05—Insulated conductive substrates, e.g. insulated metal substrate
- H05K1/056—Insulated conductive substrates, e.g. insulated metal substrate the metal substrate being covered by an organic insulating layer
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/0271—Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/02—Details
- H05K1/0277—Bendability or stretchability details
- H05K1/028—Bending or folding regions of flexible printed circuits
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K1/00—Printed circuits
- H05K1/18—Printed circuits structurally associated with non-printed electric components
- H05K1/189—Printed circuits structurally associated with non-printed electric components characterised by the use of a flexible or folded printed circuit
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/22—Secondary treatment of printed circuits
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/01—Dielectrics
- H05K2201/0137—Materials
- H05K2201/0154—Polyimide
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/02—Fillers; Particles; Fibers; Reinforcement materials
- H05K2201/0203—Fillers and particles
- H05K2201/0206—Materials
- H05K2201/0209—Inorganic, non-metallic particles
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
- H05K2201/10—Details of components or other objects attached to or integrated in a printed circuit board
- H05K2201/10007—Types of components
- H05K2201/10106—Light emitting diode [LED]
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/03—Metal processing
- H05K2203/0315—Oxidising metal
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
- H05K2203/30—Details of processes not otherwise provided for in H05K2203/01 - H05K2203/17
- H05K2203/302—Bending a rigid substrate; Breaking rigid substrates by bending
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
- H05K3/00—Apparatus or processes for manufacturing printed circuits
- H05K3/38—Improvement of the adhesion between the insulating substrate and the metal
- H05K3/386—Improvement of the adhesion between the insulating substrate and the metal by the use of an organic polymeric bonding layer, e.g. adhesive
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/49126—Assembling bases
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/4913—Assembling to base an electrical component, e.g., capacitor, etc.
- Y10T29/49144—Assembling to base an electrical component, e.g., capacitor, etc. by metal fusion
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49117—Conductor or circuit manufacturing
- Y10T29/49124—On flat or curved insulated base, e.g., printed circuit, etc.
- Y10T29/49147—Assembling terminal to base
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12535—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] with additional, spatially distinct nonmetal component
- Y10T428/12556—Organic component
- Y10T428/12569—Synthetic resin
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
- Y10T428/24942—Structurally defined web or sheet [e.g., overall dimension, etc.] including components having same physical characteristic in differing degree
- Y10T428/2495—Thickness [relative or absolute]
- Y10T428/24967—Absolute thicknesses specified
- Y10T428/24975—No layer or component greater than 5 mils thick
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31678—Of metal
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/31504—Composite [nonstructural laminate]
- Y10T428/31678—Of metal
- Y10T428/31681—Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.]
Definitions
- This invention is directed to a flexible substrate structure used for LED (light emitting diode) mounting and Interconnection.
- Insulated metal substrates are being used for the mounting and interconnection of light emitting diodes (LEDs) in applications such as display back lighting, automotive lighting and general commercial and consumer lighting uses.
- the substrates currently being used are generally rigid and are not able to be deformed and bent without degradation or damage to their mechanical, electrical and thermal properties. It is desirable to be able to form or bend such substrate materials to make angles, curves or bends, while maintaining mechanical and thermal integrity and without causing degradation of the substrate or of its electrical properties.
- Multi-functional electronic substrate materials of various kinds are known in the art. Some of the layers of these substrates can be made of various polymer materials such as polyimide (hereinafter referred to as “PI”). In general, these are rigid structures with little flexibility, unless the structure is grooved.
- PI polyimide
- US 2007/0076381 A1 describes a flexible heat spreader circuit board with a heat sink.
- the flexibility of its circuit board results from a pattern of grooves that make an upper surface and a lower surface flexible when the substrate is bent.
- Aluminum substrates are known for use in visible LED Circuits. Canadian Electronics Magazine e-magazine, for example as shown in an article titled “Aluminum Substrates Make light work of visible LED Circuits” by Tom Morris, dated Sep. 18, 2007. Economical solderable polymer thick film conductors can be screen printed directly onto such substrates, without degradation.
- the thermally conductive aluminum alloy material enables design engineers to mount high power LED components directly to it. However, no mention is made of any flexibility of such alloy substrates.
- the substrates As applications expand requiring more complex mechanical configurations and circuitry becomes thinner and more complicated, it is desirable for the substrates to be shapeable without any resulting degradation of the substrate surface characteristics or without interfering with their thermal or electrical properties. It is also desirable for chosen substrates to be cost effective, be easy to handle and be able to be used in fixtures allowing the best use of the light from an LED.
- the laminate described in the present patent application is useful in such fixtures as it can be shaped for improved optical properties without any degradation of its electrical properties and with its thermal properties maintained.
- the ability to bend a laminated structure without degrading the electrical circuitry allows the configuring of LED's in a “3D” format. Such structures are not limited to a planar format. Having this bendable ability provides the device designer with more options to tailor and optimize the device design. Overcoming the limitations in LED mounting and LED structure and fixtures imposed by rigid substrate materials and interconnection materials allows the designer to customize and optimize the mechanical features found in Solid State lighting components.
- the present flexible structure is expected to increase overall optical electrical efficiency from 30% to 40% of the range currently seen in LED structures and to optimize the configuration manually by allowing the bending at the most efficient configuration to concentrate and disperse LED light.
- the present invention concerns a laminate comprising, on a substrate the following layers:
- the laminate may be a thin polymer based copper clad filled polyimide (PI), for example a CooLamTM thermal laminate such as LC (Alumina Filled PI) and LX (Alumina Filled PI), used in conjunction with an aluminum alloy composition substrate.
- PI copper clad filled polyimide
- the laminate may also be an anodized aluminum CooLamTM thermal laminate, such as LU (Anodized Aluminum and with adhesive).
- LU Alodized Aluminum and with adhesive
- a suitable family of materials useful in this invention is the CooLamTM thermal laminates.
- Examples are embodiments such as LC (Alumina Filled PI), LU (Anodized Aluminum with adhesive) and LX (Alumina Filled PI).
- a CooLamTM structure consists of a metal, optionally an adhesive (only in the LU (Anodized Aluminum with adhesive) embodiment), polyimide (PI), copper foil and a solder mask. See drawings FIG. 3A and 3B (key). LU products may also be alumina filled.
- FIG. 1 shows a typical laminate substrate, with bend locations 6 , 7 and 8 .
- FIG. 2 shows the detail of test lines 6 . Two traces that were measured are labeled 9 and 10 .
- FIG. 3(A) shows the stacking arrangements of CooLamTM Laminates.
- FIG. 3(B) serves as a “key” to the drawing in FIG. 3(A) .
- the 1 ⁇ 2 ounce to 4 ounces Cu, in metric units, is “14.79 milliliters to 118.29 milliliters”.
- the term “laminate” herein is referred to as the metal ( 1 ) and the polyimide ( 3 ), and adhesive ( 2 ) where adhesive is present, plus the copper foil ( 4 ).
- substrate refers to the metal itself ( 1 ).
- the finished product with patterned copper foil and solder mask ( 5 ) is called a “Metal Core Printed Circuit Board” or an “Insulated Metal Substrate” (IMS).
- the copper is at 18 um, the dielectric is at 6 um and aluminum is at 100 um. In another embodiment the copper is at 35 um, dielectric is at 12 um and the aluminum is at a thickness selected from the following group of thicknesses: 200 um and 247 um.
- the composite films of the present invention are generally derived from a multi-layer structure having one or more polyimide composite layers. These polyimide composites and layers can have thermal conductivity, electrical conductivity, electrical resistivity, electrical capacitance and other desirable properties. They can also be layered in various ways to create other sought after properties. An example of such a layering plan for a coating on a substrate is described in U.S. Pat. No. 7,100,814, which is incorporated herein by reference. Some of the layered structures known in the art lack flexibility which results in cracking and breakage upon their use. The laminate thickness is from about 125 microns to about 3 millimeters. Allowing substrate flexibility results in cost reduction, the need for fewer pieces, need for less handling and greater ease of installation, along with improved appearance and the ability to create custom shapes and more efficient configurations to concentrate or distribute light, offering improved illumination and appearance characteristics.
- Tests to determine interconnection integrity of CooLamTM laminate under bending stress were performed on substrates fabricated with 17 micron thick CooLamTM thermal laminate and 2 mm thick Aluminum Alloy 5005 using a LCD Backlight Unit circuit design. The purpose of this testing was to determine the feasibility of offering this type of construction for applications in LED lighting.
- the overall sample size was 17 mm ⁇ 423 mm (5 ⁇ 8′′ ⁇ 17′′) and consists of 6 identical segments is shown in FIG. 1 .
- FIG. 1 Three locations on each of six pieces were tested as shown in FIG. 1 .
- the bend point centerline on each segment was positioned on the centerline of a 11 ⁇ 8′′ diameter mandrel and bent by hand to an approximate 90 degree bend.
- the laminate/conductor was on the outside of the bend putting the material in tension.
- the actual bend profile for each location tested was traced or compared to prior sample traces and entered in a notebook with the test data.
- Table 1 tabulates the resistance test results for the configurations. Visual examination at the bend point evidenced no cracking or crazing of the solder mask. Resistance measurements were performed using an Electro Scientific Industries 1700 series Micro-Ohmmeter system using the 20 milliohm range (resolution of 1 micro Ohm).
- the average change in resistance of all the circuit lines was 1.55 milliohms with a maximum of 3 milliohms and a minimum of 0.8 milliohms. This testing indicates that the CooLamTM material used in a metal-backed structure has the potential to be bent to 90 degrees or greater angles with reliable interconnections.
Abstract
This invention is directed to bendable circuit substrate structures useful for LED mounting and interconnection.
Description
- This invention is directed to a flexible substrate structure used for LED (light emitting diode) mounting and Interconnection.
- Insulated metal substrates are being used for the mounting and interconnection of light emitting diodes (LEDs) in applications such as display back lighting, automotive lighting and general commercial and consumer lighting uses. The substrates currently being used are generally rigid and are not able to be deformed and bent without degradation or damage to their mechanical, electrical and thermal properties. It is desirable to be able to form or bend such substrate materials to make angles, curves or bends, while maintaining mechanical and thermal integrity and without causing degradation of the substrate or of its electrical properties.
- Multi-functional electronic substrate materials of various kinds are known in the art. Some of the layers of these substrates can be made of various polymer materials such as polyimide (hereinafter referred to as “PI”). In general, these are rigid structures with little flexibility, unless the structure is grooved.
- US 2007/0076381 A1, for example, describes a flexible heat spreader circuit board with a heat sink. The flexibility of its circuit board results from a pattern of grooves that make an upper surface and a lower surface flexible when the substrate is bent.
- Aluminum substrates are known for use in visible LED Circuits. Canadian Electronics Magazine e-magazine, for example as shown in an article titled “Aluminum Substrates Make light work of visible LED Circuits” by Tom Morris, dated Sep. 18, 2007. Economical solderable polymer thick film conductors can be screen printed directly onto such substrates, without degradation. The article mentions that aluminum alloy substrates can be extruded, die cast and made in special shapes. The thermally conductive aluminum alloy material enables design engineers to mount high power LED components directly to it. However, no mention is made of any flexibility of such alloy substrates.
- In an article titled “Poor fixtures threaten to jeopardize the illumination potential of LEDs” by Richard Stevenson, Compound Semiconductor, June 2007, the author points out that the low efficiency of many fixtures in the industry results from lack of skills relating to working on the design aspects of these fixtures, by the workforce of many companies, who work with the electrical systems used in powering LEDs. These techniques are needed for thermal management and optical design.
- As applications expand requiring more complex mechanical configurations and circuitry becomes thinner and more complicated, it is desirable for the substrates to be shapeable without any resulting degradation of the substrate surface characteristics or without interfering with their thermal or electrical properties. It is also desirable for chosen substrates to be cost effective, be easy to handle and be able to be used in fixtures allowing the best use of the light from an LED. The laminate described in the present patent application is useful in such fixtures as it can be shaped for improved optical properties without any degradation of its electrical properties and with its thermal properties maintained. The ability to bend a laminated structure without degrading the electrical circuitry allows the configuring of LED's in a “3D” format. Such structures are not limited to a planar format. Having this bendable ability provides the device designer with more options to tailor and optimize the device design. Overcoming the limitations in LED mounting and LED structure and fixtures imposed by rigid substrate materials and interconnection materials allows the designer to customize and optimize the mechanical features found in Solid State lighting components.
- The present flexible structure is expected to increase overall optical electrical efficiency from 30% to 40% of the range currently seen in LED structures and to optimize the configuration manually by allowing the bending at the most efficient configuration to concentrate and disperse LED light.
- The present invention concerns a laminate comprising, on a substrate the following layers:
- (a) a copper or aluminum metal layer;
- (b) a polyimide or adhesive layer, the metal layer being adjacent to the polyimide or adhesive layer
- (c) copper foil layer and
- (d) liquid or film solder mask layer.
- The laminate may be a thin polymer based copper clad filled polyimide (PI), for example a CooLam™ thermal laminate such as LC (Alumina Filled PI) and LX (Alumina Filled PI), used in conjunction with an aluminum alloy composition substrate. The laminate may also be an anodized aluminum CooLam™ thermal laminate, such as LU (Anodized Aluminum and with adhesive). Such laminates must be designed to be used in a composition of the proper thickness for LED applications. Use of such laminates creates a versatile and bendable structure for ease of use in LED packaging.
- As pointed out above, a suitable family of materials useful in this invention is the CooLam™ thermal laminates. Examples are embodiments such as LC (Alumina Filled PI), LU (Anodized Aluminum with adhesive) and LX (Alumina Filled PI). A CooLam™ structure consists of a metal, optionally an adhesive (only in the LU (Anodized Aluminum with adhesive) embodiment), polyimide (PI), copper foil and a solder mask. See drawings
FIG. 3A and 3B (key). LU products may also be alumina filled. -
FIG. 1 shows a typical laminate substrate, withbend locations -
FIG. 2 shows the detail of test lines 6. Two traces that were measured are labeled 9 and 10. -
FIG. 3(A) shows the stacking arrangements of CooLam™ Laminates.FIG. 3(B) serves as a “key” to the drawing inFIG. 3(A) . InFIG. 3(B) the ½ ounce to 4 ounces Cu, in metric units, is “14.79 milliliters to 118.29 milliliters”. - Referring to
FIGS. 3(A) and 3(B) , the term “laminate” herein is referred to as the metal (1) and the polyimide (3), and adhesive (2) where adhesive is present, plus the copper foil (4). The term “substrate” refers to the metal itself (1). The finished product with patterned copper foil and solder mask (5) is called a “Metal Core Printed Circuit Board” or an “Insulated Metal Substrate” (IMS). - In one embodiment, the copper is at 18 um, the dielectric is at 6 um and aluminum is at 100 um. In another embodiment the copper is at 35 um, dielectric is at 12 um and the aluminum is at a thickness selected from the following group of thicknesses: 200 um and 247 um.
- The composite films of the present invention are generally derived from a multi-layer structure having one or more polyimide composite layers. These polyimide composites and layers can have thermal conductivity, electrical conductivity, electrical resistivity, electrical capacitance and other desirable properties. They can also be layered in various ways to create other sought after properties. An example of such a layering plan for a coating on a substrate is described in U.S. Pat. No. 7,100,814, which is incorporated herein by reference. Some of the layered structures known in the art lack flexibility which results in cracking and breakage upon their use. The laminate thickness is from about 125 microns to about 3 millimeters. Allowing substrate flexibility results in cost reduction, the need for fewer pieces, need for less handling and greater ease of installation, along with improved appearance and the ability to create custom shapes and more efficient configurations to concentrate or distribute light, offering improved illumination and appearance characteristics.
- Tests to determine interconnection integrity of CooLam™ laminate under bending stress were performed on substrates fabricated with 17 micron thick CooLam™ thermal laminate and 2 mm thick Aluminum Alloy 5005 using a LCD Backlight Unit circuit design. The purpose of this testing was to determine the feasibility of offering this type of construction for applications in LED lighting.
- The overall sample size was 17 mm×423 mm (⅝″×17″) and consists of 6 identical segments is shown in
FIG. 1 . - Three locations on each of six pieces were tested as shown in
FIG. 1 . The resistance of two 11.8 mil 1.4 mil thick traces, shown as 9 and 10 inFIG. 2 , in each location was measured before and after bending. The bend point centerline on each segment was positioned on the centerline of a 1⅛″ diameter mandrel and bent by hand to an approximate 90 degree bend. The laminate/conductor was on the outside of the bend putting the material in tension. The actual bend profile for each location tested was traced or compared to prior sample traces and entered in a notebook with the test data. The following Table 1 tabulates the resistance test results for the configurations. Visual examination at the bend point evidenced no cracking or crazing of the solder mask. Resistance measurements were performed using an Electro Scientific Industries 1700 series Micro-Ohmmeter system using the 20 milliohm range (resolution of 1 micro Ohm). - The average change in resistance of all the circuit lines was 1.55 milliohms with a maximum of 3 milliohms and a minimum of 0.8 milliohms. This testing indicates that the CooLam™ material used in a metal-backed structure has the potential to be bent to 90 degrees or greater angles with reliable interconnections.
-
TABLE 1 RESISTANCE RESISTANCE BEFORE AFTER RESISTANCE BENDING- BENDING- CHANGE- SAMPLE LOCATION TRACE MILLIOHMS MILLIOHMS MILLIOHMS 1 1 1 17.3 18.2 0.9 1 1 2 17 17.9 0.9 1 2 1 17 18.5 1.5 1 2 2 17.6 18.4 0.8 1 3 1 17.4 18.5 1.1 1 3 2 17.8 18.6 0.8 2 1 1 17.3 19.3 2 2 1 2 17.2 19 1.8 2 2 1 17.7 19.4 1.7 2 2 2 18.1 19.2 1.1 2 3 1 17.8 18.6 0.8 2 3 2 17.6 19.7 2.1 3 1 1 17.8 19.6 1.8 3 1 2 16.5 19.5 3 3 2 1 17.9 19.6 1.7 3 2 2 17.6 19.3 1.7 3 3 1 18.2 19.3 1.1 3 3 2 17.8 19.4 1.6 4 1 1 18.5 19.5 1 4 1 2 18 19.9 1.9 4 2 1 18.2 19.8 1.6 4 2 2 17.9 19.7 1.8 4 3 1 17.9 19.7 1.8 4 3 2 18 19.6 1.6 5 1 1 17.3 19.2 1.9 5 1 2 17.9 19.8 1.9 5 2 1 17.6 19.3 1.7 5 2 2 18 19.2 1.2 5 3 1 17.7 19.8 2.1 5 3 2 17.9 19.4 1.5 6 1 1 17.9 19.2 1.3 6 1 2 17.9 19.8 1.9 6 2 1 18.3 19.6 1.3 6 2 2 18.1 19.7 1.6 6 3 1 17.9 19.5 1.6 6 3 2 18.3 19.9 1.6
Claims (2)
1-16. (canceled)
17. A method of manufacturing a light emitting diode (“LED”) lighting composition, comprising:
bending a circuit structure for LED mounting to a 90° or greater angle, the circuit structure for LED mounting comprising the following layers:
(a) circuitry traces of copper or aluminum;
(b) a polyimide or adhesive layer, the metal layer being adjacent to the polymide or the adhesive layer
(c) a copper foil layer and
(d) a liquid or film solder mask layer
wherein the circuit structure for LED mounting has an increase in electrical resistance of less than 10% after bending.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/269,148 US20120024579A1 (en) | 2007-12-04 | 2011-10-07 | Bendable circuit structure for led mounting and interconnection |
US13/965,778 US8707551B2 (en) | 2007-12-04 | 2013-08-13 | Bendable circuit board for LED mounting and interconnection |
US14/254,142 US20140226347A1 (en) | 2007-12-04 | 2014-04-16 | Bendable circuit board for led mounting and interconnection |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US522207P | 2007-12-04 | 2007-12-04 | |
PCT/US2008/085292 WO2009073670A1 (en) | 2007-12-04 | 2008-12-03 | Bendable circuit structure for led mounting and interconnection |
US74468510A | 2010-05-26 | 2010-05-26 | |
US13/269,148 US20120024579A1 (en) | 2007-12-04 | 2011-10-07 | Bendable circuit structure for led mounting and interconnection |
Related Parent Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2008/085292 Continuation WO2009073670A1 (en) | 2007-12-04 | 2008-12-03 | Bendable circuit structure for led mounting and interconnection |
US12/744,685 Continuation US20100304180A1 (en) | 2007-12-04 | 2008-12-03 | Bendable circuit structure for led mounting and interconnection |
US74468510A Continuation | 2007-12-04 | 2010-05-26 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/965,778 Continuation US8707551B2 (en) | 2007-12-04 | 2013-08-13 | Bendable circuit board for LED mounting and interconnection |
Publications (1)
Publication Number | Publication Date |
---|---|
US20120024579A1 true US20120024579A1 (en) | 2012-02-02 |
Family
ID=40394177
Family Applications (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/744,685 Abandoned US20100304180A1 (en) | 2007-12-04 | 2008-12-03 | Bendable circuit structure for led mounting and interconnection |
US13/269,148 Abandoned US20120024579A1 (en) | 2007-12-04 | 2011-10-07 | Bendable circuit structure for led mounting and interconnection |
US13/965,778 Active US8707551B2 (en) | 2007-12-04 | 2013-08-13 | Bendable circuit board for LED mounting and interconnection |
US14/254,142 Abandoned US20140226347A1 (en) | 2007-12-04 | 2014-04-16 | Bendable circuit board for led mounting and interconnection |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
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US12/744,685 Abandoned US20100304180A1 (en) | 2007-12-04 | 2008-12-03 | Bendable circuit structure for led mounting and interconnection |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
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US13/965,778 Active US8707551B2 (en) | 2007-12-04 | 2013-08-13 | Bendable circuit board for LED mounting and interconnection |
US14/254,142 Abandoned US20140226347A1 (en) | 2007-12-04 | 2014-04-16 | Bendable circuit board for led mounting and interconnection |
Country Status (6)
Country | Link |
---|---|
US (4) | US20100304180A1 (en) |
EP (1) | EP2227926A1 (en) |
JP (1) | JP2011507235A (en) |
CN (1) | CN101869006A (en) |
TW (1) | TWI554149B (en) |
WO (1) | WO2009073670A1 (en) |
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WO2009073670A1 (en) * | 2007-12-04 | 2009-06-11 | E. I. Du Pont De Nemours And Company | Bendable circuit structure for led mounting and interconnection |
CN101742814B (en) * | 2009-12-22 | 2011-08-24 | 华为终端有限公司 | Printed circuit board shielding method and printed circuit board |
US20130199771A1 (en) * | 2010-04-13 | 2013-08-08 | Ube Industries, Ltd. | Heat-dissipating substrate for led |
US8637880B2 (en) | 2010-12-22 | 2014-01-28 | E.I. Du Pont De Nemours And Company | Three dimensional light emitting diode systems, and compositions and methods relating thereto |
US8629464B2 (en) | 2010-12-22 | 2014-01-14 | E. I. Du Pont De Nemours And Company | Three dimensional light emitting diode systems, and compositions and methods relating thereto |
JP5432201B2 (en) * | 2011-03-30 | 2014-03-05 | Jx日鉱日石金属株式会社 | Copper alloy sheet with excellent heat dissipation and repeated bending workability |
JP5961970B2 (en) * | 2011-10-06 | 2016-08-03 | 大日本印刷株式会社 | Laminated body and element using the same |
SG191883A1 (en) * | 2011-10-18 | 2013-08-30 | Fischer Technology Pte Ltd | A method of moulding |
US20140340873A1 (en) * | 2013-05-20 | 2014-11-20 | Ko-Chun Chen | Bendable heat readiating composite and backlight unit having the same |
US10199138B2 (en) | 2014-02-05 | 2019-02-05 | Essex Group, Inc. | Insulated winding wire |
US9324476B2 (en) * | 2014-02-05 | 2016-04-26 | Essex Group, Inc. | Insulated winding wire |
WO2015130681A1 (en) | 2014-02-25 | 2015-09-03 | Essex Group, Inc. | Insulated winding wire |
DE102014010329A1 (en) * | 2014-07-14 | 2016-01-14 | Carl Freudenberg Kg | Laminate for the production of an IMS circuit board and IMS circuit board |
CN104976578A (en) * | 2015-07-29 | 2015-10-14 | 陈丽晓 | Deformable solar lamp sheet |
GB2545906A (en) * | 2015-12-23 | 2017-07-05 | Univ Southampton | Modular electronic structures |
US20170356640A1 (en) | 2016-06-10 | 2017-12-14 | Innotec, Corp. | Illumination assembly including thermal energy management |
JP2018056397A (en) | 2016-09-29 | 2018-04-05 | 日亜化学工業株式会社 | Method for manufacturing metal base substrate, method for manufacturing semiconductor device, metal base substrate, and semiconductor device |
JP6359605B2 (en) * | 2016-11-15 | 2018-07-18 | 株式会社京写 | Printed wiring board |
US10488028B2 (en) * | 2017-05-03 | 2019-11-26 | Fluence Bioengineering, Inc. | Systems and methods for a heat sink |
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Also Published As
Publication number | Publication date |
---|---|
JP2011507235A (en) | 2011-03-03 |
EP2227926A1 (en) | 2010-09-15 |
TW200932047A (en) | 2009-07-16 |
US20100304180A1 (en) | 2010-12-02 |
CN101869006A (en) | 2010-10-20 |
US20140226347A1 (en) | 2014-08-14 |
WO2009073670A1 (en) | 2009-06-11 |
US8707551B2 (en) | 2014-04-29 |
US20130330533A1 (en) | 2013-12-12 |
TWI554149B (en) | 2016-10-11 |
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Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |