BG110492A - A method for preparation of high-power multi-chips with light-emitting diodes - Google Patents

Abstract

The method for preparation of high-power multi-chips with light-emitting diodes is applied to the preparation of super high-power multi-chips with light-emitting diodes, more specifically for the preparation of super high-power structures with better cooling and high light release, effective and reliable functioning. It is applicable for the creation of super high-power light-emitting structures for the purposes of electric light technology. In particular, it gives a possibility to secure a wealth of powers of light-emitting multi-chips, depending on the aims of the specific applications in the electric light technology. The structure obtained is composed of a cooling copper pad (1) milled in a definite way, an epoxy mask (2), powerful light emitting diodes (3) with high-brightness emission, the anode and the cathode of the light diodes are soldered upon the printed-circuit card (4), the thermal pad is soldered on the copper pad according to a technology for a surface assembly (SMD). The cooling copper pad (1) and the printed-circuit card (4) are glued together by epoxy mask (2). The direct soldering of the thermal platforms on the copper pad allows for a considerably better cooling, for effective and reliable work of the high-power diodes.

Description

Technical field

The invention relates to a method for manufacturing high-power multichips with high-power LUXEON® Rebel LEDs by SMD technology of mounting LED elements with cooling pad, which allows significantly better cooling and efficient and trouble-free operation of high-power LEDs at high light output.

It is applicable for the creation of ultra high power LED devices intended for use in various lighting fixtures and appliances. In particular, the method makes it possible to provide a wide range of LED multichip capacities, depending on the purpose of the specific lighting applications.

BACKGROUND OF THE INVENTION

Light sources with longer life and greater energy efficiency are becoming increasingly important, and in this regard alternative light sources are of increasing interest. Current trends in LED manufacturing methods, in particular the development of multichip and modular LEDs, have contributed to the emergence of more powerful LEDs of different colors. LED sources are used in many applications from signal lights to substitutes for conventional incandescent and discharge light sources, as well as in fiber optic systems. Due to the fact that LEDs consume less electricity than conventional light sources, while having significantly longer life and radiation focused in the visible spectrum, they can be an effective alternative to the latter in various types of lighting such as street, park and street lighting. , theatrical, architectural, stage and interior.

Despite all the benefits of LED sources, their light output and lifetime are very sensitive to temperature and, in fact, are often lowered due to too much. · * · «···· · ········, _{tt β} high temperature. LED structures should be able to provide good and intense heat, which is essential for maintaining its stable operation.

One such solution is known from the patent of Korean manufacturers of LEDs and super high-power LEDs SAILUX, Inc. No. 2005 - 0069100, corresponding to patent No. US 2009/00030003 A1, published on Jan 1, 2009. It describes an LED device, structure of the LED device and method for producing the modular LED structure. It includes a main cooling pad formed by a heat dissipating material, in which the first receiving slit has an open upper portion and the first portion has an inner diameter which gradually increases in the direction of the lower position, at least one insulating base formed by an insulating material and reaching the lower surface of the first receiving slit of the main cooling pad, and at least one main frame reaching the insulating pad. According to the LED device, the packaging structure of the LED device and the manufacturing method of the packaged LED device, the LED chip can be mounted on a large main cooling platform and the light can be focused, therefore improving the radiation efficiency and cooling capacity.

The technical solution described has several important disadvantages: The first is the insufficient efficiency of the device with the use of high-power LED chips that are connected in series by technology through bonding. In this method, the chips have relatively small distances from each other, which degrades the heat dissipation, however effective the cooling capacity of the device is. In addition, bonding technology - connecting the chips to thin wires produces shaded sections on the radiating surface that reduce the performance of the LED chips.

The second is the use of sophisticated components to form the structure, as well as the use of a metal cooling pad. The third is the use of inefficient fresnel optics, which reflects much of the light rays and reflector surfaces to focus and direct the light beams of the LED chips, which again is ··· »· ♦♦ ·· er ·· · · ♦ · ** • · · · · «· · ·· • · · ·· · · ····· * * ····· * ♦ ····· ·· · ·« _ee ><

related to the uneconomical and inefficient operation of the device with respect to the use of LED chip radiation.

The third disadvantage is that the aforementioned disadvantages consume electricity for illumination due to the lower efficiency of the optical system and the incomplete use of light source radiation due to the insufficient cooling capacity of the device. And this is especially important when it comes to energy efficiency.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a compact and economical structure with high-power, high-efficiency LEDs by surface mount technology, which enables trouble-free operation of high-power LEDs and efficient heat transfer in operating mode, providing trouble-free operation of high-light-emitting diodes and enabling for the production of a wide range of ultra high power LED multichips for application in various areas of lighting technology. It offers a simplified design, unification of structural elements and easy automation of the device manufacturing process.

The method of designing devices with high-power LEDs LUXEON® Rebel by SMD technology of installation of LED components with cooling copper backing, which allows significantly better cooling and efficient and trouble-free operation of high-power LEDs at high light output.

The method of manufacturing LUXEON® Rebel high-power LED devices using SMD technology for mounting LED components with a cooling copper substrate for use in the creation of ultra-high-power LED devices for use in various luminaires and systems according to the invention includes elements and components according to the invention the following functional structure and function: cooling copper substrate 1, milled in a specific manner, on which an epoxy mask 2 is applied, a printed circuit board 4 with a configuration providing impervious connection of high-performance LEDs, terminals to power them block and bearing lead-free solder paste 5, designed for surface mounting of the LED elements 3, and mounting holes 6.

High brightness LEDs are high power. For the developed prototypes of the multichips, LUXEON® Rebel and Rebel ES LEDs with a luminous yield of 100 Im / W were maintained with a stabilized current of 350 mA provided by power supplies generating stabilized current. The number of LEDs in multi-chip prototypes is consistent with the standard multiplicity of current generators with respect to the power of the connected load.

For sustainable and trouble-free operation of LED sources with adequate light output, it is necessary to provide them with the catalog operating temperatures of the transition or, more precisely, to provide them with the necessary cooling in the operating mode. Often, the solution to this problem is decisive for the mode of operation of high-power LEDs, as well as determining the constructive designs of devices with high-power LEDs and their technical data. The production technology of the developed prototypes of multichips with LEDs allow trouble-free operation of the LEDs and at an operating current of 700 mA, whereby for an LED with a rated output of 350 mA, a luminous flux of 100 Im and a luminous yield of 100 Im / W, the consumed power increases to 2.38W, their luminous flux to 180 Im, and their light output decreases to 76 Im / W. That is, to obtain similar lighting results, it would be possible to use a smaller number of LEDs in the multichip, when operating in maximum allowable operating current mode and with no need for cooling.

The construction of the multi-chips includes a cooling copper substrate 1 milled in a specific manner on which the epoxy mask is applied 2. The required number of PCBs is glued / pressed onto the substrate. The boards 4 are of fiberglass with a configuration that provides the necessary circuitry for connecting high power LEDs and terminals to the power supply unit. The soldering paste 5 is applied to the circuit boards in accordance with the European RoHS Directive to restrict the use of certain hazardous substances in electrical and electronic products. · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · , mercury, cadmium, hexavalent chromium (Chromium VI or Cr6 +), polybrominant biphenyls (PBB), polybrominant diphenyl ether (PBDE). The LUXEON® Rebel type 3 LEDs according to the SMD surface mounting technology are soldered on them in succession. This process is accomplished by using a RoHS type 5 solder paste and heating the circuit board in a special oven using the method of surface mounting of electronic components. The main advantages of the method are: minimizing the size of the elements and hence the size of the products themselves; automation of the installation process; increase of PCB strength - vibration resistance, shocks; improving the heat exchange between the elements and the circuit board. The proposed method allows for the production of a wide range of high-power, extremely economical multichips with different power and very high light output. For comparative evaluation of the proposed multichips with high-power LEDs made by technology by bonding or connecting the respective points of the chip to the terminals by means of a thin wire, Table 1 and Table 2 can be used. Table 1 presents the realized technical parameters of prototypes with power 2, 4 , 6 and 8 W at 350 mA LED current and 3.4 V operating voltage, and 5, 10, 14, 20 W respectively at 700 mA LED current and 3.2 V.

I ·

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Table 1

A prototype multichip with LUXEO M®Re be! neutral, white 3.4 6,8 14 20 27 350 warm white 3.4 6,8 14 20 27

neutral, white warm white

100 200

120

400

240

600 800

360 480

neutral, white warm white neutral, white warm white neutral, white warm white neutral, white warm white neutral, white warm white neutral, white warm white

100 84

Table 2

Table 2 shows the catalog parameters of the super high power LEDs offered by SAILUX, Inc..

As can be seen, with the method of the invention the realized light flux at a power of 2W, an operating current of 350 mA, exceeds the light flux of that proposed by Sailux, Inc. 5W multichip, 350 mA working current. This is mainly due to the higher • r

light output of the components used and the ability to provide them with an efficient and trouble-free operation. As the constructive implementation of the developed method allows trouble-free operation of the LEDs and at a working current of 700 mA, the achieved results at a working current of 700 mA and a voltage of 3.2 V. are presented for comparative evaluation. high light output, but the light output of the light source is reduced. Using the high-current-mode LEDs, similar high-tech parameters can be achieved for ultra-high-power LEDs with a reduced number of constituent high-power LEDs, which in turn allows the device to be reduced in proportion to the reduced number of elements.

By combining chips with the required number of high-power LEDs, depending on the requirements for the specific application, it is possible to realize a wide range of LED multichips with different power - 2, 4, 6, 8, 10, 12, 14, etc. ., as well as the corresponding capacities for an equal number of high-power LEDs and increased operating current.

The exemplary embodiments of the devices according to the developed method provide uniform conditions for their normal operation and show the versatility of the application of the method for the production of ultra high-power LED multichips, as well as its efficiency with respect to the achieved electrical and lighting parameters.

The low energy consumption of the lighting fixture and the efficient use of electrical and light energy, the high mechanical strength as well as its adaptability to illumination of different objects make it extremely convenient for use in a variety of lighting systems.

The advantages of the method are locked in the following:

1. Achieving the required lighting parameters with minimum installed power. Maximum Utilization of Electric and Light Energy and Functioning of the High Efficiency Device Due to Proposed Technology for the Production of Ultra High Power Multichips with High Power LUXEON® Rebel LEDs with Extremely High · · · · · · · • · ♦ · · · · · ···· • · ····· «······ ···« '" _{is <efficiency} and visokoyarkostno radiation. This fact makes the lighting fixture extremely energy efficient;

2. Achieving compactness of the manufactured devices and ensuring efficient heat transfer and trouble-free operation of the LEDs and at increased operating current due to the applied SMD technology for mounting the LED sources on boards, which provides the following advantages: minimizing element sizes and from the dimensions of the products themselves; automation of the installation process; increase of PCB strength vibration resistance, shocks; improving the heat exchange between the elements and the circuit board;

3. With the same number of LED sources different lighting parameters can be achieved, which is due to better cooling and the possibility of trouble-free operation of the LEDs in the mode of high current;

4. With a different number of LED sources, similar lighting parameters can be achieved only by selecting a working mode, which makes it possible to reduce the cost of the device;

5. Universal application in different types of lighting fixtures and installations due to the ability to produce a wide range of LED multichips with different power;

6. The design incorporates technologically simplified elements, which contributes to its compactness and allows unification of basic, repetitive elements and technological operations.

Claims (5)

1. A method for manufacturing high-power multichip LEDs comprising a sequentially connected main cooling pad, insulating base and main frame, characterized in that: a cooling pad / 1 / made of copper and milled in a specific manner is connected in series with an epoxy mask / 2 / for bonding, printed circuit board / 4 / of foil fiberglass with a configuration providing the necessary circuit for connecting high-power LEDs, terminals to the power supply unit and applied lead-free paste 151, intended for arhnosten installation of LED elements / 3 / and mounting holes / 6 /. A method for manufacturing high-power multichips with LEDs according to claim 1, characterized in that the production of ultra-high-power multichips by SMD technology for mounting high-power LEDs glued / pressed to a cooling substrate / 1 / milled in a certain way, cut with copper mask / 2 / enables the achievement of the required lighting parameters with minimum installed power, maximum utilization of electrical and light energy and operation of the device with isok efficiency, ensuring effective heat and hassle-free operation of LEDs and increased operating current. 3. A method for manufacturing high-power multichip LEDs according to claim 2, characterized in that, by providing efficient heat-insulation and the possibility of trouble-free operation of the LEDs / 2 / at increased current in operating mode with the same number of LED sources, different lighting parameters and with different number of LED sources, similar lighting parameters can be achieved only by selecting a working mode, which makes it possible to reduce the cost of the device th. 4. A method of manufacturing high-power LED multichips according to claim 3, characterized in that it has a cost-effective construction and universal application in various types of lighting devices and systems due to the ability to produce a wide range of LED multichips with different power and allows for unification of basic, repetitive elements and technological operations. A method for manufacturing high-power multichip LEDs according to claim 4, characterized in that it includes technologically simplified elements, which allows the unification of the basic, repetitive elements and technological operations.