There are still white LED luminous uniformity of poor, closed not long life of such issues, can not play a white LED was looking forward to the application of merit.  But on the demand level, not only the general lighting purposes, with the phone, LCD TV, automotive, medical, and so the broad application, making the most suitable development and stability of the white LED technology research results on a wide range of concerns.
 To improve the luminous efficiency white LED, there are two directions, first, improve the LED chip size, to increase the volume of luminescence. 。 The second is the number of small chip in with a package under a module.
 By increasing chip area to increase the volume of LED
 Although the LED chip size will be large, this can be much higher brightness, but too much of the area in the application process and the results will appear just the opposite phenomenon. Therefore, for such problems, some LED industry on the basis of the electrode structure and flip chip to improve the construction, improvement in the chip surface, to achieve 50 lm / W luminous efficiency.  For example, in the white LED flip chip packaging part, because luminous layer is very close to the vicinity of the package, luminous layers of light to the outside San Chu, the electrodes will not be obscured, but the drawback is that the heat generated by not easy to disperse.
 Not to improve the chip surface, coupled with the increase in chip area can quickly upgrade the absolute brightness, because when the light from outside the proliferation of internal radio chip, chip in some of these improvements can not be reflective, light on the admission will be That limit, according to calculations, the best play-efficient LED chip size is about 7 mm2.
 Packaging use several small LED chips to rapidly improve the efficiency of LED
 And the LED chip size compared to using low-power LED chips packaged as a module with, it was able to quickly achieve high brightness, for example, Citizen will be eight small LED package together so that the luminous efficiency module Reached a 60 lm / W, is the industry's first.
 However, this approach has caused some concern, because it will be more than in the same package LED modules, must be placed some insulation materials, so as to avoid short-circuit between the LED chip to happen, so will increase the number of The cost.
 Citizen's explanation is this: "The cost of the impact of the rate is very small, because in comparison to the overall cost of these insulation materials only less than 1 per cent, and can make use of existing insulation materials applications, These insulating materials do not need to re-development, does not need new equipment to be. "
 Although the Citizen's explanation is reasonable in theory, but no experience in the industry, this is a challenge, because the yields, research and development, production projects are needed to be overcome. There are other ways to achieve the goal of improving the efficiency of luminescence, many businesses found that the LED sapphire substrates to create rugged tan structure, this may raise output capacity, therefore, have gradually move towards the establishment of the chip surface Texture or Photonics Crystalline structure. For example, Germany is the OSRAM to develop such a framework "Thin GaN" high-brightness LED.  Principle is in InGaN layer formed on the metal film and then stripping Sapphire, so that metal film will be produced images of the effects get more light out, according to OSRAM information, such a structure will be 75 per cent of the out-efficiency .
 In addition to the chip-out efforts of the area needs to be done, because look forward to a higher-efficiency, is also part of the package must do some improvements. In fact, an increase of one per project will bring to light some impact on the efficiency of removal, but this does not represent, because the process on the package will increase the higher-loss, as developed by the Japanese plane OMROM Light source technology, we can significantly enhance the efficiency of light out, such a structure will be fired by the LED light, optical systems and the use of LENS reflex control of the optical system to do, so OMROM called "Double reflection".  Use of such a structure, the traditional shells, such as the LED package caused by the loss of light, in view of the wide angle of reflection package to obtain a higher-efficiency, further, the surface formed by Mesh on the processing And the formation of a two-tier reflection effects, such an approach can be good-efficiency out of control. This special design, use of reflective performance for high-efficiency removal of the LED, the main use is for LCD TV backlighting applied.

 Packaging materials and fluorescent material to increase the importance of
 If the expectations used as a backlit LCD TV applications, NA me to overcome the problem would be even more.  LCD TV because of the continuous use time as long as several hours, or even 10 hours, so long as the use of such cases, used as a white LED backlighting will not have to have a row arising from the use of brightness Attenuation of the situation.
Has been published by the high-power white LED, the LED power is a low-power white LED brightness of the few times, so look forward to using high-power white LED to replace fluorescent lamps as lighting equipment, then there is a need to overcome the difficulties is the brightness Decreasing the situation.  For example, the white LED long continuous use 1 W circumstances, would create continuous use after the first half of the time gradually reduce the brightness of the phenomenon, not only high-power white LED to appear this is the case, low-power white LED there will be such a The problem is only because of the low-power white light of different products, and will not be particularly highlighted such problems.
 The greater use of the current, given the higher the brightness, which is generally for high-brightness LED to achieve the concept, however, because the use of the current increase, packaging materials can withstand such a long time because the currents generated by the The heat, but also because such a continuous use, often the thermal resistance packaging materials will be reduced to 10 k / w below.
 High-power LED the heat is low-power LED several times, it will appear as the temperature rose, and a luminous power to reduce the problem, so the heat can be high on the development of packaging materials, the relatively significant Is very important.
 Perhaps in 20 ~ 30 lm / W following the LED, these issues are not clear, however, once faced 60 lm / w more luminous high-power LED time, we need to find ways to solve. Thermal effects brought about by the impact will not just only LED itself, but on the whole that have plagued many applications, so, LED in this area if we can get resolved, NA me, can also reduce the application of the product itself the heat Burden.  Therefore, in the face of continuously improve the current situation at the same time, how to increase thermal capacity, at this stage is the need to be insurmountable problems.  From all sources, in addition to the problems of materials, including packaging materials from the chip to the heat, thermal structure and packaging materials to the PCB board of the heat, thermal structure and heat dissipation of the PCB board Structure, the need for comprehensive considerations.  For example, even if the chip can be solved from the package materials to the heat, but from the package to the cooling effect of PCB-bad, is also the result of the LED chip temperature rise, decline in the efficiency of a luminous phenomenon.。 So, like the Panasonic To address this problem, beginning in 2005, then, including radio, line, surface-white LED, and the PCB substrate integrated into the design, to overcome may appear in the package to the PCB board Thermal interruption of the problem.  However, not all of the industry like Matsushita, because the industry's strategy, some industry to design a simple substrate for the goal, only for the PCB board cooling structure improved. There are quite a number of industries, because their production LED, it can only do some research and development PCB board, but this alone is not enough, so it is necessary to choose a good cooling of the white LED.  PCB board allow the use of metal materials, with white LED package in the cooling tank closely connected to the cooling capacity. This looks as if only because expectations to achieve cooling, and a simple matter to be complicated, in the end this is not the cost and progress of the concept of  Application to today's level, it is very difficult to make a judgement, however, is that some industry is towards this area for consideration, such as the Citizen in 2004 published by the products, is able to package on the thickness of 2 ~ 3 mm casual Thermal heat from outside groove, to provide application because the industry can use the cooling tank with high-power white LED, allows the cooling plate PCB design to play an important role.

 Packaging material change to white LED life of the original four times the heat problem is not only affect the performance of brightness, but also the life of the LED itself a challenge, so in this part, LED continuously developed Packaging materials to be sustained increase in brightness LED of the impact.
 The past used as packaging materials of epoxy resin, heat resistance is rather poor, may appear in the life of LED chips themselves before arrival, epoxy resin has a discoloration on the situation, therefore, in order to improve the cooling, we must let More of the current release. In addition, not only because of the phenomenon will have an impact on epoxy resin, or even short-wave length of the epoxy will cause some problems, it is relatively easy because the epoxy was white LED in the short wavelength light damage, even low-power The white LED will have on the damage caused by epoxy resin, not to mention high-power white LED contained in the short wavelength light more and also accelerate the deterioration of the natural, even for some products in the light of life after less than 5,000 hours .  So, instead of continuing to overcome because the old packaging materials - epoxy problems brought about by the change, as towards the development of a new generation of packaging materials of choice.  In this life to solve the problem, many LED packaging industry have given up towards the epoxy resin, instead of the silicone and ceramic, etc., as packaging material. According to statistics, because of changes in the packaging materials, can in fact improve LED life. Information on the point of view, instead of epoxy resin packaging materials - silicone, has a high heat resistance, according to trial, even in the 150 to 180 degrees Celsius temperature, the phenomenon will not change color, looks like it might be A good packaging material.
 Silicone can be scattered near the blue and ultraviolet light, compared with epoxy resin and silicone materials can be inhibited because the current and short-wavelength light of the deterioration brought about by the phenomenon, easing the rate of decline in light penetration.  Application to the present, almost all the high-power white LED products have been used as a package of silicone material, for example, compared to 400 ~ 450 nm wavelength of light, epoxy resin in a bit about a few percentage around, But silicone to 400 ~ 450 nm light absorption of less than 1.0%, such a gap, making the anti-short-wavelength, the silicone is a good performance.
 On the performance of life, the silicone can be achieved to extend the service life of white LED target, or even reach more than 40,000 hours of life. But do not really suitable for lighting applications have yet to be research, because silicone is flexible soft material, so in the packaging process, the need to pay special attention to the application, thereby design the most appropriate application of technology.
 For future applications, improve white LED light output efficiency will be key to winning the point.  White LED production techniques, from a blue LED and yellow YAG phosphor mix, developed a simulation of white, to the use of colour or mixed use GaN materials, developed a white LED, the application, can already see the Will be in the direction towards a more extensive expansion.  In addition, the luminous white LED efficiency, have a good development, and promote the Japan Association of LED lighting goal is to look forward to in 2009 to 100 lm / w the luminous efficiency, is expected in the next few years, 100 lm / w LED Efficiency can actually commercial applications.

 Nichia Chemical actively develop the semiconductor laser white LED to the ball in the hope that the white color of high purity and high brightness, at the request of the industry continued to improve from each area, to achieve this goal, but the pace of progress, It is still quite slow.  So some industry began to consider using other technologies to achieve the industry similar to the brightness white LED requirements.  In high-brightness blue and white LED's on-field chemistry, put part of a research and development direction, towards the development of white light laser to do.
 Nichia Chemical and white LED using the same materials production of GaN semiconductor lasers, developed a white light, with the present performance, the luminance has been able to achieve 10 cd / mm around the existing white LED to achieve this-if expectations Of the value is very difficult, even if the current expectations of increased brightness, but this will make the junction temperature rise, brought about by the results would not only reduce the efficiency of the entire luminous, but also waste a lot of electricity.
 Nichia Chemical developed by the White semiconductor lasers, chip-in fluorescent materials no longer in use, but will be white and Luminescence part of the part dealt with separately, using 200 mw of blue-violet semiconductor laser, a 405 nm wavelength of light, the blue Color or blue-violet semiconductor laser and optical fiber connection to the face, white fluorescent material from the Tu fiber fired on the other side, and that generated by the white diameter only 1.25 mm, the only area of the same amount of light the white LED 1 / 20, less than the required power 0.1 W, therefore, not in the heat of the need to consider too many.
 Although the look of the area is quite good, but there are some shortcomings in life, only around 3000 hours, the price is too expensive.  Although the price spend some time on the issue may be reduced by some, but now 300,000 yen to the standard view, to be reduced to 30 or even 300 yen, may need more than 10 years of time.