KR20070032326A - High power led electro-optic assembly - Google Patents

Abstract

The present invention provides a power LED electro-optical assembly 40 that includes a conductive heat sink 18 and an LED 14 mounted at one end of the heat sink. The LED 14 is in electrical coupling with the heat sink 18. Assembly 40 also includes a reflector 2 mounted to the other end of the heat sink. An insulating adhesive material 19 is provided between the reflector and the sink. The assembly 40 also extends through the reflector 12 and has a conductive adhesive pin 15 that forms a conductive bond therewith and an electrical coupling 16 that electrically couples the pin 15 to the LEDs 14. Also includes. Finally, the electrical sleeve assembly 30, in which the sleeve 32 is coated with an electrically insulating coating, is applied to the LED electro-optical assembly.

Heat Sinks, LEDs, Reflectors, Adhesive Materials, Adhesive Pins, Electrical Couplings

Description

HIGH POWER LED ELECTRO-OPTIC ASSEMBLY

FIELD OF THE INVENTION The present invention relates to light emitting diode ("LED") technology, and more particularly to an LED assembly that is enhanced to provide a desired light output for various light applications.

LED assemblies are known and commercially available. Such assemblies are typically used in a variety of applications for ultraviolet radiation, for example used to effect curing of photoinitiated adhesives and coating compositions.

Several factors affect the fabrication of LED assemblies. One is the control of the high current supplied to the LEDs to provide a stable and reliable UV source. Another is the placement of the lens to hold the output lens in place. In addition, the means for providing the passage for electric conduction needs to supply a control unit for the LED. As the current into the LEDs increases, the need for high current, high stability electrical contacts is essential. In addition, reflectors are often needed to form light rays that emit from the LEDs. In addition, a cooling system is required to handle the heat coming from the assembly. At present, the available LEDs cannot adequately provide all these requirements.

At present, manufacturers offer a wide range of LED packages of various types. Such packages range from conventional LED lamps to LEDs using emitter chips of various sizes. While many known LED assemblies produce high light output, they produce very scattered wide-angle beams that are difficult to obtain effective collimation and beam imaging in practical applications such as flashlights. As a result, much of the output energy is lost by leaking from the side of the LED package.

In addition, the light emitted from the LED assembly is typically unevenly distributed. The shape of the light emitting chip is projected onto the target as a high intensity region. Reflected light from the electrode and the wall due to the unpredictable light pattern is superimposed on the main beam. As a result, undesirable hot spots and shadows appear on the object being irradiated. Thus, for any light application requiring substantially even or uniform light distribution over a given area, a transmissive or partial diffuser is used to disperse the light emitted from each individual LED assembly so that hot spots and shadows are illuminated. It must not appear on the object to be However, while the diffuser removes hot spots and shadows, it is important that the "directionality" or geometry of the light beams emitted from the individual LED assemblies is not degraded or reduced.

In order to overcome these above mentioned disadvantages of known light sources, there is a need to provide LED curing lamp assemblies that have a flexible design and are easy to manufacture and reduce assembly costs.

In one embodiment of the invention, an LED electro-optic electrical sleeve assembly is disclosed having a generally cylindrical sleeve coated with electrical insulation. The assembly is divided into upper and lower parts, and the upper and lower parts are separated by insulating material. At least one LED and a conductive reflector are mounted on top, and the reflector surrounds the LED. The conductive heat sink is mounted on the bottom and is in electrical coupling with the LED. In addition, the conductive adhesive pins extend through the conductive reflector and conductively bond with it. The electrical coupling causes the adhesive pin to electrically couple to the LED, and the heat sink and reflector form an electrically conductive location for supplying power to the LED.

1 is a schematic view of an LED beam forming the contact assembly of the present invention.

FIG. 2 is a schematic diagram of an LED optical conversion assembly forming the contact assembly of FIG. 1 and using light rays. FIG.

3 is a schematic representation of an electrical sleeve assembly of the present invention.

4 is a schematic diagram of an LED, electro-optical assembly of the present invention.

Referring to Figure 1 of the present invention, a schematic diagram of an LED light shaping contact assembly 10 is shown. Assembly 10 is a compact means that provides a method of simultaneously contacting an LED to electrical contacts and forming light rays exiting the LED as described later. The contact assembly 10 is divided into two contacts made of metal, namely an electrode, an upper electrode 10a and a lower electrode 10b. The upper electrode 10a includes a metal reflector 12, which is preferably made of aluminum. The metal reflector 12 is pressed into the electrode 10a to form a conductor reflector assembly. The metal reflector 12 may be curved and generally serve to collimate and direct LED light towards the lens, as described in more detail below. In a preferred embodiment, the reflector 12 may be elliptical. The LED chip 14 is mounted to the electrode 10a, preferably centered and partially or completely surrounded by the reflector 12. The LED chip 14 is also electrically insulated from the reflector 12. Since the metal is an electrical conductor, both the metal reflector 12 and the metal electrode 10a provide an electrical transmission path away from the LED chip 14. The conductive metal pin 15, which is preferably coated with gold, is pressed into the assembly 10 of the upper electrode 10a as shown in FIG. Electrical couplings, such as gold wires or wires 16, advance from the top electrode 10a to the lead chip 14. One end of the gold wire 16 is soldered to the metal pin 15 and the other end is welded to the top surface of the LED chip 12 to electrically couple the pin 15 to the LED 14.

When current flows through the chips of the individual LED 14 assemblies, both light and heat are generated. Increasing current through the chip raises the light output, but increased current flow also raises the chip temperature of the individual LED assemblies. This increase in temperature lowers the chip's efficiency. Overheating is a major cause of breakage of individual LED assemblies. To ensure safe operation, as a result of light output, some other means must be provided to keep the current at a low level or to transfer heat away from the chip of the individual LED assembly. Therefore, the lower electrode 10b may also be formed by an electrically conductive heat sink 18 that serves to transfer heat away from the LED chip 14. The upper electrode 10a and the lower electrode 10b are held together by an electrically insulating material 19 such as a nonconductive adhesive. The LED 14 is disposed in the assembly 10 in such a manner that the bottom surface is glued or soldered to the heat sink 18 through the adhesive material 19. To enable electrical connection via the LED 14, a voltage is applied to both the upper and lower electrodes 10a and 10b, respectively. This causes the heat sink 18 to absorb heat and the curved surface of the reflector 12 forms the light from the LEDs 14 in a predetermined pattern. Although only a single LED 14 is shown in FIG. 1, it can be appreciated that multiple LEDs can be used in the assembly 10.

By having one of the electrical contacts 10a coupled with the reflector and the remainder coupled with the heat sink, the LED light shaping contact assembly 10 is easy to manufacture, reducing assembly costs and simplifying final assembly. Moreover, the LED light shaping contact assembly 10 allows scaling up to multiple LEDs of the assembly without further adding significant complexity.

To further illustrate the operation of the entire optical assembly, FIGS. 2A-2C show an exemplary light diagram for a single LED assembly. It will be appreciated by those skilled in the art that similar light diagrams are generated when the LED chip 14 of a single LED assembly is replaced with multiple LED chips 14.

2A-2C illustrate an LED optical conversion assembly 20 using the LED forming contact assembly 10 of FIG. 1 in combination with a miniature optical element to form a complete light beam forming system. The optical element includes a lens 22 that directs the light generated by the LED chip 14 to a predetermined location by focusing the light at a predetermined spot size by collimating the light. The lens 22 is precisely attached or molded into the assembly so that it is centered in the collimated beam. The shape and / or size of the lens 22 can be changed to form a conical beam of light emitted from the LED to provide the desired optical illumination pattern.

The act of collecting to one point of the lens 22 depends on both the radius of the lens 22 and the position of the lens 22 with respect to the individual LED assembly 20. Both the radius and position of the lens 22 can be formed during the design process to optimize irradiation of the object. The ability to precisely position and fix the optical lens 22 is an important concept for the application. Lens 22 needs to be positioned at the correct distance from LED 14 to achieve the desired light output.

In Fig. 2A, the ball-shaped optical lens 22 is partially located in the reflector 12 of the upper electrode 10a. Although a ball shaped optical lens 22 is shown in the present invention, it will be appreciated that other shaped lenses may be selected. The lens can be changed according to a predetermined output. In the present invention, the ball lens 22a is selected to produce the maximum optical power density at the available LED output. The LED output is concentrated at a predetermined spot outside the ball optical lens 22a. If a collimation beam is required, it is preferable to use a half ball optical lens 22b as shown in Fig. 2B or a parabolic optical lens 22c as shown in Fig. 2C. The half ball optical lens 22b of FIG. 2B is positioned in such a way that a portion of the lens lies on the reflector 12 and the other portion is outside of the assembly 20. This positioning of the lens 22b, as shown in Figure 2B, radiates a wider light pattern to illuminate a larger area on the workpiece. On the other hand, the parabolic optical lens 22c is located completely outside of the reflector 12 and / or the assembly 20 as shown in FIG. 2C. This positioning of the lens 22c of FIG. 2C emits a narrower light pattern than the area of FIG. 2B to illuminate a specific area on the workpiece. This method provides a rigid assembly that can be manufactured precisely and quickly. The LED light shaping contact assembly size, other optical lenses 22 can be varied as desired, and the distance and position between the LEDs 14 and the lenses 22 can be varied over a wide range of optical configurations while reducing cost and complexity of the finished assembly. Can be changed to accommodate the element.

The number of LED assemblies used determines the size of the LED array and the desired output intensity. The end user can easily increase or decrease the output intensity by adding an LED assembly to or removing the LED assembly from the LED array. In addition, a user can change the operating wavelength of the assembly by replacing one or more LED assemblies having a first operating wavelength with one or more replacement assemblies having a second wavelength. In addition, the user can replace a damaged or stopped LED assembly without replacing the total LED arrangement.

With respect to the optical properties of each of the optical assemblies 10 and 20, the LED 14 emits emitted light at a given light power and at a given optical wavelength. Exemplary LED 14 according to the present invention preferably emits optical power greater than 500 mw at 405 nm. When the LED 14 is placed at a predetermined position in the reflective cavity, the reflective cavity collimates most of the emitted light emitted by the LED 14. Parabolic reflector 12 represents an exemplary reflective cavity that collimates most of the light when LED 14 is disposed at or near the focal point of elliptical reflector 12, as shown in FIG. It will be appreciated by those skilled in the art that the collimation means of the present invention is not limited to elliptical reflector 14. Other LED collimation means, which are well understood by those skilled in the art, may also be practiced in the present invention.

Preferably, to make a compact optical assembly, such as an LED optical assembly, it is necessary to have a means for holding the output lens in place and also to have a passage for electrical conduction. One such means is the electrical sleeve assembly 30 shown in FIG. Assembly 30 is preferably conducted with an aluminum alloy comprising a generally cylindrical sleeve 32 which is preferably made of aluminum coated with an electrically insulating coating 34 such as a nonconductive adhesive. As will be described in more detail later, the outside of the sleeve 32 is hidden to contact the external electrical connection. 3 shows a cutaway view of an assembly 30 having a slot 36 on top. These slots 36 are preferably machined into the sleeve after the sleeve 32 has been coated. Since slot 36 now allows bare metal assembly 30 to be exposed over a wide area, a conductive coating such as adhesive may be applied between sleeve slot 36 and the metal contacts inside sleeve 36. When the entire exposed surface provides very low contact resistance. The conductive adhesive connects the reflector 12 inside the assembly to the outside of the sleeve 32. Alternatively, wire bonding may be applied to attach the reflector 12 to the sleeve 32. Two slots 36 provide four open surfaces for contacting the sleeve 32. The electrical conductivity is also maximized due to the length of the slot 36 and the fact that two surfaces for each of the two slots 36 provide the maximum surface area in the compact assembly. The top shape of the sleeve 32 is preferably changed to hold the lens used for the assembly 30. By simply positioning the lens of the sleeve 32 and sliding it on the LED assembly and then applying a conductive adhesive to the slot 36 and wire-bonding the reflector 12 to the sleeve 32, further with reference to FIG. As described in detail, the electro-optical assembly is electrically connected.

To form the completed electro-optical assembly 40 as shown in FIG. 4, the LED 14 is an electronic sleeve assembly 30 having a beam forming contact assembly 10, an LED variable optical assembly 20 and an LED lens. ) The LED 14 is glued or soldered to a heat sink 18 made of an electrically conductive material. When the LED 14 is connected to the heat sink 18 with insulating material 19, the ray shaping contact assembly 10 is glued in place. In addition, the top surface of the LED 14 is bonded to the conductive metal pin 15 via the gold wire 16. The pin 15 is preferably coated with gold and is pressed with a metal contact assembly. Since the contact assembly metal is selected for reflectivity and electrical conductivity, it can serve to induce the LED output and to electrically connect the top surface of the LED 14 to the outer surface of the light forming contact assembly 10. Next, the LED variable optical assembly 20 is preferably provided with a ball optical lens 22a.

Finally, the electrical sleeve assembly 30 holding the LED lens is installed by applying a structural adhesive 34 on the heat sink 18. Reflector 12 is preferably bonded to heat sink 18 with structural adhesive 34. Thus, the structural adhesive 34 serves to hold the assembly fixedly together, providing some thermal conductivity and additional electrical insulation from the heat sink 18.

In addition, the conductive adhesive 36 is preferably applied to the slot 36 to adhere the outside of the sleeve 32 to the reflector 12. Alternatively, as described above, a wire, preferably aluminum (not shown), may be used to bond the wire between the reflector 12 inside the assembly and the outer sleeve 32, which is preferably made of aluminum. Preferably, multiple wire bonding may be used to bond recesses (not shown) below the surface of reflector 12 and outer sleeve 32. In addition, the recess is preferably coated for protection. The conductive material is heat cured and the completed LED electro-optical assembly 40 is formed. In addition, the assembly 40 shows only a single LED 14, but preferably multiple LED devices can be attached to the assembly.

Individual alignment of the LEDs 14 or multiple LEDs is necessary because the two individual LED assemblies are not completely identical. Differences arise from the positioning of the chip 14 in the reflector 12, the positioning of the reflector cup 12, the positioning of the electrodes 10a and 10b and the positioning of the optical lens 22. All of these factors affect the geometry and direction of the light beam. Due to the manufacturing process of the individual LED assemblies, the components of the individual LED assemblies exhibit a very wide range of positional relationships. Therefore, for any application requiring irradiation of a particular area, each individual LED assembly must be manually aligned and then permanently held in place by some mechanical support means.

Although a single LED is used herein to describe the invention, those skilled in the art can understand that the invention described herein can be applied to multiple LEDs or LED arrays. The plurality of LEDs may be arranged in a predetermined manner for irradiation.

In the present invention, the LED 14 is shown to be a rectangular frame, but according to the disclosed invention the LED illuminator includes, but is not limited to, light curing, video, shop windows, photography or specialty displays for light for a wide range of applications. It will be understood by those skilled in the art that the present invention may be formed into any shape suitable for providing. Because of the durability and robust construction of the disclosed LED illuminators, they may be used in outdoor settings, marine applications or in adverse environments.

Claims (40)

One or more LEDs, A conductive heat sink mounted in electrical coupling with the LED at one end; A conductive reflector mounted at the one end of the heat sink and surrounding the LED; An insulating member for electrically insulating the conductive reflector from the heat sink; A conductive adhesive pin that forms a conductive bond with the conductive reflector and extends through the conductive reflector; An electrical coupling portion coupling the adhesive pin to the LED, The heat sink and the reflector form an electrically conductive location for powering the LED. The LED electro-optical assembly of claim 1, wherein the heat sink comprises a planar surface at the one end and the LED is mounted to the surface. The LED electro-optical assembly according to claim 2, wherein the reflector is an elliptical reflector having a central opening therethrough, and wherein the LED is mounted to the central opening. 4. The LED electro-optical assembly of claim 3, wherein the insulation member comprises an adhesive for securing the conductive reflector to the heat sink. The LED electro-optical assembly of claim 1, wherein the heat sink is a heat pipe. The LED electro-optical assembly of claim 1, wherein the adhesive pin is gold plated. The LED electro-optical assembly of claim 1, wherein the wire bonding is a wire jumper interconnecting the adhesive pins to the LED. The LED electro-optical assembly of claim 1, further comprising an optical lens member positioned adjacent the light reflector, wherein the optical lens member is spaced apart from the LED to focus light rays emitted from the LED. 8. The LED electro-optical assembly of claim 7, wherein the optical lens member is at least partially supported within the light reflector. 8. The LED electro-optical assembly of claim 7, wherein the optical lens member is a ball lens for production of improved optical power density. 8. The LED electro-optical assembly of claim 7, wherein the optical lens member is a half ball lens for the production of collimated light. 8. The LED electro-optical assembly of claim 7, further comprising a conductive retaining sleeve for supporting the heat sink, the reflector, and the optical lens member. 13. The LED electro-optical assembly of claim 12, wherein the conductive sleeve is disposed in electrical continuity with the conductive reflector. The LED electro-optical assembly of claim 13, wherein the conductive sleeve is insulated from the heat pipe. The LED electro-optical assembly of claim 13, wherein the conductive sleeve is insulated from the heat pipe by an insulating adhesive securing the sleeve to the heat pipe. The LED electro-optical assembly of claim 13, wherein the conductive sleeve is insulated coated. 16. The LED electro-optical assembly of claim 15, wherein the sleeve comprises one or more passageways adjacent to the conductive reflector. 18. The LED electro-optical assembly of claim 17, wherein the passageway is filled with a conductive adhesive to form a conductive bond between the sleeve and the reflector. 18. The LED electro-optical assembly of claim 17, wherein the passage is electrically coupled with the sleeve and the reflector. Attaching one or more LEDs to the conductive heat sink to be conductive; Surrounding the LED with a conductive reflector; Electrically coupling the adhesive pin to the LED; And the reflector includes adhesive pins extending therethrough. 21. The method of claim 20, further comprising interposing an insulating material between the reflector and the heat sink. 21. The method of claim 20, wherein enclosing comprises disposing an insulating adhesive between the reflector and the heat sink. 21. The method of claim 20, wherein the step of attaching the wire comprises interposing a conductive adhesive wire between the pin and the LED. 21. The method of claim 20, wherein the heat sink is a heat pipe. LED electro-optic retention assembly, An overall cylindrical sleeve having a top and a bottom and coated with an electrically insulating material, One or more passageways located thereon for insertion of the adhesive, And the upper portion is modified to retain the electron optics. 27. The LED electro-optic retention assembly of claim 25, wherein the sleeve is comprised of aluminum or an alloy thereof. 27. The LED electro-optic retention assembly of claim 25, wherein the adhesive provides a conductive bond between the sleeve and the metal contact inside the top. 28. The LED electro-optic retention assembly of claim 27, wherein the adhesive is a conductive adhesive. 28. The LED electro-optic retention assembly of claim 27, wherein the adhesive is a wire. 28. The LED electro-optic retention assembly of claim 27, wherein the upper portion includes a first electrode member and a press-in reflective surface is mounted therein. 28. The LED electro-optic retention assembly of claim 27, wherein the lower portion includes a second electrode member having an electrically conductive heat sink mounted therein. An overall cylindrical sleeve coated with an electrically insulating material and having a top and a bottom separated by an insulating member, One or more LEDs and conductive reflectors mounted on the top; A conductive heat sink configured to be electrically coupled to the LED and mounted to the lower portion; A conductive adhesive pin that forms a conductive bond with the conductive reflector and extends through the conductive reflector; An electrical coupling portion coupling the adhesive pin to the LED, The reflector surrounds the LED and the heat sink and reflector form an electrically conductive location for powering the LED. 33. The LED electro-optic electrical sleeve assembly of claim 32, further comprising a pair of slots positioned at the top. 34. The LED electro-optic electrical sleeve assembly of claim 33, wherein the slot is coated with a conductive adhesive to adhere the slot to the reflector. 34. The LED electro-optical electrical sleeve assembly of claim 33, wherein the reflector is attached to the sleeve via an aluminum wire. 33. The LED electro-optical sleeve assembly of claim 32, wherein the reflector is bonded to a heat sink by the insulation member. 33. The LED electro-optical electrical sleeve assembly of claim 32, further comprising an optical lens member positioned adjacent the reflector, wherein the optical lens member is positioned spaced from the LED to focus light rays emitted from the LED. 38. The LED electro-optic electrical sleeve assembly of claim 37, wherein said upper portion retains said optical lens member. 38. The LED electro-optic electrical sleeve assembly of claim 37, wherein the optical lens member is at least partially supported within a reflector. 38. The LED electro-optical electrical sleeve assembly of claim 37, wherein the optical lens member is located completely outside of the reflector.

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