A higher proportion of the cost structure of the LED package for grain, lenses, substrate, phosphor, and packaging such as plastic bracket, LED packaging adhesive must be able to effectively blocked with anti-wavelength ultraviolet light, heat, insulation, anti-static and moisture-resistant. Changes in the LED industry, which over the years have come from changes in the material, resulting in brightness rising, its application has also been extended. Dynamic analysis of the industry and manufacturers of plastic packaging following on LED Silicone (Silicone).
Silicone encapsulation material properties
Source: Topology Research Institute finishing, 2007/03
A. LED Application of Multivariate 2007 the global packaging market value of about $ 7.4 billion
LED brightness enhancement, product life extension, resulting in a more diverse LED applications, from major exhibitions and related products released at the meeting, is not difficult to see that the application has been expanded to large size LED backlight panels, headlights, projector lamps, indoor and outdoor decorative lights and special lighting, etc., can be said for the LED industry to inject more new life.
According to estimates Topology Research Institute (TRI), and in 2007 the global LED market value will reach $ 7.4 billion, mainly due to growing year by year, but the end product demand affect prices, making 2007 the global LED market scale harvest of about 8.5 % over the 2006 slowdown. Expected in 2008 will be subject to lower LED technology to enhance the case, the end product is more diverse and mature applications, will have the opportunity to grow to 13.4 percent.
Figure a 2007 global LED packaging market size estimates $ 7.4 billion
Source: Topology Research Institute, 2007/03
With recent breakthroughs in LED materials technology, LED encapsulation mode also changed, from the early single wafer Lamp evolved into SMD, HB LED; its operating current from the early low-power LED, progressed to 1A of current high-power LED, have a variety of different uses in accordance with the practice of the package of the LED.
Comparison Table A major packages
Source: related companies; Topology Research Institute of Industrial Finishing, 2007/03
II. Silicone (Silicone) plastic packaging industry development and issues
Currently the most commonly used LED package epoxy resin adhesive (epoxy), but due to the epoxy resin, the lower wavelength LED aging fast, and a high temperature will accelerate the aging, which aging will affect the LED colors gradually turn yellow. Thus R & D in the United States Lumileds Silicone (Silicone) sealant to improve its optical transmittance, refractive index and heat resistance.
(A) the development of LED status plastic packaging materials
1. Epoxy
Colorless transparent epoxy resin, low impurities principle, having excellent mechanical properties, insulation, corrosion resistance, adhesion, and low shrinkage of the important chemical material. Case in LED packaging, LED epoxy resin must have a high transmittance, high refractive index, heat resistance, moisture resistance, insulation resistance and chemical stability properties, currently perfusion and transfer molding methods, the plastic packaging need to use epoxy.
Figure two solid LED packaging material manufacturing processes
Source: related companies; Topology Research Institute of Industrial Finishing, 2007/03
Because of the cost considerations, electrical characteristics, epoxy glue for mainstream LED package, the current development of epoxy resin with UV-resistant LED, high heat resistance, high heat resistance and high refractive index as the future direction of development.
Development 2. Silicone (Silicone) plastic packaging material status
Si (silicon) on the basis of raw material is silica sand as a refinement of its characteristic heat, and from climate impacts (including: rain, snow, ice, hail, ultraviolet (UV), odor (O3) and extreme temperatures under) case, no aging harden, crack, flake, corruption or embrittlement.
Advantages of silicon resin (silicone) are: very excellent high temperature stability, excellent weather resistance, very excellent adhesion, excellent shock absorption and cushioning properties, very excellent dielectric properties, chemical stability and security, and reliability.
Table II silicon resin encapsulation material properties
Source: Topology Research Institute finishing, 2007/03
In terms of the amount of plastic packaging, general packaging material amount of shell-type surface-mount type is about 10 times. Shell-type low-priced goods, lower power to the indicator-based, only a small number of classes will use less silicon resin, mainly applications using silicon resin encapsulated in 0.5W / chip SMD type above.
Table III using silicon resin encapsulation of the LED type
Source: Topology Research Institute finishing, 2007/03
Source: Topology Research Institute finishing, 2007/03
The future direction of (b) plastic packaging materials
As the future of LED with high power, high color rendering, energy saving, long life, low-cost mercury and its development trends, the future of LED industry will move towards the development of new products, and its development focus are: (1) substrate technology; (2 ) phosphor new material; (3) a resin material; (4) a thermally conductive material; (5) an optical system; (6) integrated technology; (7) the crystal growth apparatus, and thus the development of packaging materials representing the very important position.
Table IV transparent packaging material development trends
Source: Topology Research Institute finishing, 2007/03
2005 After the LED optical output power is increased due to the short wavelength emitted from the LED chip such that the faster aging of the epoxy resin, silicon resin, future needs will surge to the current application point of view, almost all of the high-power white LED product has been changed to a silicon resin as packaging material, but because the price is too high, replace the effect of the future still depends on the price of silicon resin may be.
Table V LED is currently the most mature in three packages
Source: Topology Research Institute finishing, 2007/03
III. 2007 silicon resin manufacturers to develop Status
At present, the development of silicon-based resin is still foreign manufacturers, semiconductor manufacturers have Shin-Etsu, Dow Corning Toray and GE-Toshiba three we provide, since the material is not easy to achieve, this is more difficult to cut Taiwan factory.
(A) Shin-Etsu Shinestu
Shin-Etsu Silicone Shinestu offer a variety of materials, including the SCR-1011A / B and SCR-1012A / B and a variety of new silicon resin products. In the 400nm wavelength penetration rate of 88% over time.
Figure III-Etsu Silicone material Shinestu SMD
Source: Shin-Etsu Shinestu; finishing Topology Research Institute, 2007/03
(B) Dow Coring
Dow Corning introduced a variety of silicone materials, including Dow CorningEG-6301, Dow Corning OE-6336 and Dow Corning JCR 6175 and other three new LED protective colloid, and combines the advantages of silicon resin, Dow Corning SR-7010 resin.
Dow Coring of SR 7010 in the 405nm wavelength penetration rate of 99% over time, the heat also can reach the standard of 180 ℃ ~ 200 ℃, more suitable for large-size backlight, automotive interior lighting and general lighting and other fields, Dow Corning also founded Light Management group, there are more and more companies to replace the original silicone epoxy applications.
Figure IV EG 6301 material compared with epoxy resin
Source: LEDs Magazine; finishing Topology Research Institute, 2007/03
(C) GE-Toshiba
GE-Toshiba Release "InvisiSi1", using a blue LED chip and a near-ultraviolet LED chip is a high output of the white LED, the epoxy resin is more than the heat, the smaller the influence of UV light. Is further extended to the future of LED lighting and headlights, high-power white LED market.
Lens shape InvisiSi1 launched three varieties formed varies. Light transmittance, the wavelength of 400nm is about 70%, and with the longer wavelength, and to improve the wavelength of 800nm, the transmission increased to 90% to 95%.
Comparison of silicon resin and epoxy resin at a temperature of 180 ℃ 14 days exposure, the transmittance of light almost does not change, when the epoxy resin under the same experimental conditions, the transmittance of 400nm light will be from the original 90% down to almost zero.
Table VI Silicone vendor comparison
Source: Topology Research Institute finishing, 2007/03
In addition, there are also the so-called industry without resin package, such as Japan's Kyocera (Kyocera) made ceramic package, is proposed for anti-aging, including ceramics also has better heat effect. Nichia metal package, replace the resin encapsulation resin deterioration solve the problem, but a substantial increase in cost, so the development of packaging material remains the main key LED mass production.
Figure V Kyocera (Kyocera) ceramic package diagram
Source: Kyocera; Topology Research Institute of Industrial Finishing, 2007/03
Four. TRI views
LED lighting in the underlying market eventually, silicone resin products have the following advantages: (1) a very excellent high temperature stability, can be -40 ℃ to + 200 ℃ temperature stability using not degenerate; (2) weather excellent, can withstand extreme temperatures; (3) a very excellent shock absorption and cushioning properties, the cured silicone products are excellent toughness elastomer, and has a good cushioning effect; and (4) excellent insulation properties; (5) the safety and reliability certification.
In the current application, almost all of the high-power white LED products have changed to a silicone resin as the encapsulation material, but because the price is too high, replace the effects of silicone resin technology to enhance and increase the demand for the future with the product, will eliminate Mi issue price.
Manufacturing LED can be said is an art, and its technology development is not just pure epitaxial downstream packaging technology and the use of plastic packaging are equally important, how to provide the best quality products, is the future of LED-related firms devote play success the key.
(TRI_ Semiconductor Optoelectronics Research Centre _ Researcher: Cai is also true)
