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High-brightness light-emitting diode (LED lights) for its small power consumption, long life, fast response speed, no flash, small, non-polluting, easy and integrated features, is becoming the traditional lighting industry upgrading to a new generation of light. In energy saving, environmental protection have become an increasing concern today, semiconductor lighting is to become the new economic growth point, and thus attaches great importance to by governments around the world, the scientific community and industry. So far, the United States, Japan, Europe, mainland China and China Taiwan, etc. have been launched their own semiconductor lighting, high power LED lighting industry has become one of the most watched industry.

It is worth noting that so far upstream epitaxial silicon technology has been mature and stereotypes, cheap LED chips have been able to meet the needs of the lighting, the transfer and development of pricing forward midstream terminal market of packaging and downstream applications. This means that who-chip applications, to create a long-life, high-efficacy power LED lighting products, who is likely to become the ultimate winner of the LED industry. High power LED lighting package and the application of the problems have become prominent, one of the most critical is how to solve the heat problem of high power LED lighting, this is not only the technical aspects of structural design and engineering applications, but also involves the thermal management mode and fluid mechanics, and other scientific issues. Completely different with the three-tier structure of the existing chip aluminum plate and a heat high-power LED series lighting technology, we developed an integrated chip integration of a cooling (two-story structure) high power LED lighting series lamps "in the technology roadmap may have the significance of the revolutionary and subversive, will become a new direction of development of high power LED lighting industry.

A high power LED lighting product status

LED luminous efficiency can make about 30% of the energy converted into light, the remaining 70% of the energy is almost converted into heat, so that the temperature of the LED. Its heat is very small, low-power LEDs, basically do not have to take cooling measures can be applied, such as instrumentation lights, lights, small-size LCD screen backlight and so on. When applied to the field of commercial buildings, roads, tunnels, mining and other lighting for high-power LEDs, the heat is a big problem. If the heat of the LED chip can not spread it out, will accelerate the aging of the chip, the light fades, color offset, shortening the life of the LED. Therefore, the structure model and thermal management design of high power LED lighting system is very important.

All high-power LED lighting on the market today are made of chip aluminum plate heat sink three-tier architecture model ", that is the first chip package formed aluminum panel LED light source module, and then the light source module placed on the radiator manufacturing into high-power LED lighting.

It should be noted that the high-power LED thermal management system still used in the LED early for lights and display lights, small power LED thermal management mode. Chip aluminum plate heat sink three-tier architecture model "Preparation of high-power LED lighting, there are obviously unreasonable in terms of system structure, such as the structure between contact resistance and high junction temperature, low thermal efficiency, so the chip The heat released can not be effectively export and shed be in the path, leading the LED lighting light efficiency is low, the light fades, life is short and can not meet the lighting needs.
How to improve the package thermal capacity is one of the key technologies of this stage, high-power LED to be solved. The direction and focus of the development of LED lighting products are: high power, low thermal resistance, higher light, low light, small size, light weight, thus making the cooling efficiency of the LED's have become increasingly demanding.

However, due to the restrictions of the structure, cost and power consumption and many other factors, high power LED lighting is difficult to use active cooling mechanism, but only the use of passive cooling mechanism, but the passive cooling has greater limitations; and LED energy conversion efficiency than low, is still about 70% is converted to heat, even if the luminous efficiency to 1 times 40% of the energy into heat. In other words, it is difficult to do not consider the extent of heat dissipation, so in the long run, the cooling of high power LED lighting is a long-standing problem.

The timing of high-power LED for lighting is now mature, and the development of efficient natural cooling thermal management systems, has become a high-power LED lighting to achieve the prerequisite and key factors of industrialization. Therefore, new technologies routes and system architecture to completely solve the cooling problem of high power LED lighting.

Two new, high-power LED lighting industry technology roadmap

Existing high-power LED lighting cooling technology exists to thermal resistance, low heat capacity, we are trying to chip a heat integration (two-story structure) model "to address the low luminous efficiency of high power LED lighting, the light fades serious cost Advanced series of questions.

2.1 technology roadmap

Chip a heat integration (two-story structure) mode, not only to go in addition to the structure of the aluminum plate, but also multiple chips on directly placed on a heat sink to form a multi-chip module single light source, was prepared by the Integrated High Power LED lamp, light source for the single, showing the surface light source or cluster light.

2.2 The key technology

How to enhance the ability to conduct heat to the chip, reduce the thermal resistance of the interface layer, related to the structural model of thermal management systems, fluid mechanics and super-thermal conductivity materials engineering applications; how to effectively control the heat storage of the heat dissipating base, planning convection heat path, the establishment of efficient natural convection cooling system, proceed from the lamp structure design.

2.3 The technical program

By changing the package structure of LED light source, the structure of cooling and lighting structure model to reduce the thermal resistance layer; super-thermal conductivity materials, to increase the thermal conductivity of the chip heat source; to optimize the thermal management system based on "chip a heat integrated two-story structure, increase air flow, the formation of natural convection.

2.4 The design concept

Prepared to take a modular high-power LED lamps. Package of light, heat, shape and structure as a whole module between the module is independent of any one module can be replaced individually when a partial failure, simply replace the faulty module without having to replacement of other modules or the overall change will be able to continue working normally. All modules part of the lamp can hand disassembly, convenient, fast, low-cost maintenance.

2.5 Design Points

System module, in addition to meet the heat lamp replacement requirements must be met for the optical (optical efficiency) demand for LED lighting, and modeling (market) demand.

3, a cooling chip integrated structure Introduction

"Chip a heat integration (two-story structure) mode is a new type of LED light source package model, structure model and thermal management system mode. High power LED lighting, the use of the technology model prepared not only completely solve the heat problem, but also effectively solved such as the problems in the distribution of light, luminous efficiency, lifetime and maintenance, has developed a long life, high luminous efficiency high-power LED series products, such as street lights, downlights, tunnel lamps, mining lamps, car headlights, landscape lights and other lighting equipment.

3.1 Technical Features

3.1.1 will be the chip and the aluminum alloy + thermal conductivity composite material matrix (radiator) to connect as a whole, the unique application of high-power LED packaging technology, will focus on multiple chip package directly on the heat dissipating base, so that the chip and the heat dissipating base the thermal resistance between the smaller, the entire cooling matrix is ​​a complete lighting, the formation of an integrated high-power LED lighting components.

3.1.2 design thermal management system based on the principle of bionics, the establishment of the two-story structure of chip integration of a cooling thermal resistance model to the junction temperature calculation and life prediction.

Chip, a heat integrated two-story structure is characterized by a direct heat source chip package on the radiator, as the heat source temperature increases, air flow occurred in the porous heat sink, porous flow channel for air convection, heat comes out automatically, to ensure the normal working of the chip in the safe use temperature range. Advanced thermal conductivity and thermal convection system to ensure good cooling effect, to further improve the luminous efficiency of the chip.

3.1.3 the chip (45mil × 45mi1), integrated package (chip concentrated in a small area), high luminous efficiency of the surface light source with high flux density, the total luminous flux, low-glare characteristics.

At present, the use of the technology has been fabricated chip heat integration (two-story structure) mode high-power LED lighting, such as street lamps, tunnel lights, downlights, spotlights. In addition, high-power LED car headlights are need to strengthen the cooling fans, difficult to meet the application requirements of the market-oriented, two-story structure made of cluster high-power LED car headlights, to solve the automotive light industry using LED light source the limitations of the manufacturing automobile headlamps

3.2 Product technical specifications and advantages

(1) cooling efficiency: the use of natural cooling methods, completely solve the problem of high power LED cooling (temperature <4 ° C, the heat sink temperature <60 ° C, measured under the conditions of the ambient temperature> 35 ℃);

(2) high current: rated current of the supply of chips in each tablet 400 - 450mA;

(3) High luminous efficiency: the entire lighting efficiency of 90.9 lm / W;

(4) long life:> 50 000h;

(5) The light is small: the lighting of Quality Supervision, Inspection and Testing Center: 1 000h life test matt decline;

(6) integrated: the integrated of COR (Chip On Radiator), the chip integrates directly bonding the radiator integrated with integrated bonding in the aluminum panel COB (Chip On Board) is completely different. Single, integrated chip showed a surface light source, a single light source or cluster light (installed glass lenses) injection;

(7) lighting effects with the conventional non-LED light source does not change the habits of mankind's run out;

(8) structure is simple: easy to maintain, without the overall change.

4, high power LED lighting industrial technology development direction

At present, the technology roadmap for high-power LED lighting industry, we believe that there are two routes to choose from: one way is to continue along the chip aluminum plate and a radiator (three-tier structure) mode "technology roadmap development; other way is to open up the "chip a heat integration (two-story structure) mode" technology roadmap. Chip integration of a heat dissipation structure "is an emerging technology, in this structure, in addition to the chip, are new, including a cooling chip integration, packaging, power, complete sets of equipment, testing, and even standard , which makes high-power LED lighting products in the life and luminous efficiency, quality, design, controllability, cost and other aspects relative chip aluminum plate and a radiator three-tier architecture model "has a distinct advantage in high-power efficient semiconductor solid-state lighting research, application and industrialization of a new field that has much to offer.