LED is a category of power can be directly translated into visible light and the radiation-emitting devices with a low voltage small power consumption, high luminescence efficiency, luminescent response time is very short, light color of pure, solid structure, impact, vibration resistance, performance is stable and reliable, light weight, small size, low cost, a series of characteristics, rapid development, is now able to mass production of the entire visible spectrum of various colors of high brightness, high-performance products. Domestic red, green, orange, yellow LED output of the world's total of about 12%. "15" during the industry goal is to achieve an annual output of 30 billion capacity AiGslnP achieve high brightness LED epitaxial films and the production of chips, with an annual output of more than one billion red, orange, yellow ultra-high brightness LED chip and GaN materials breakthrough in the key technology, blue, green, white LED which mass production. It is projected that by 2005 the international LED market demand of about 200 billion, sales amounted to 80 billion U.S. dollars. Links to the LED industry, upstream LED chip substrate and substrate production, mid-stream industries into LED chip design and production, downstream to the LED packaging and testing, research and development of low thermal resistance. excellent optical properties and high reliability of packaging technology is a new LED toward practical, market-oriented industrialization of strategic road in a sense is to link industry and the bonds market, only Packaging can become a good end product, can be put on practical applications, in order to provide customers with services that the industry chain are linked together, seamless flow. LED Packaging particularity LED Packaging Technology is the separation device packaging technology based on the development and evolution come, but it is very special. Under normal circumstances, the separation of the device was sealed in the core Packaging body Packaging role is mainly to protect the chip and complete the electrical interconnection. LED Packaging, which is the complete output signals, tube-normal work output : visible functions, both electrical parameters, with the optical parameters of the design and technical requirements, not simply to the separation device for LED Packaging. LED luminous part of the core of p-type and n-type semiconductor pn junction constitute the core tube, When injected into the pn junction minority carrier and the majority of carrier recombination, will emit visible light, ultraviolet, or near-infrared. But pn junction issued for the non-photon orientation, in terms of the direction of all the same probability, therefore, is not the core of all light can be released, which mainly depend on the quality of the semiconductor material, Core structure and geometry, Packaging internal structure and encapsulation materials, application requirements to improve the LED, external quantum efficiency. Conventional Φ5mm LED Packaging is the length 0.25mm square chip in sintering or bonding wire shelves, Core cathode through the point of contact with the spherical gold-thread, and the bond for Wire connected with a pin, Anode through reflection Cup and the other wire-to-pin, and then top with epoxy resin encapsulation. Reflection Cup role is a collection pipe-side, the optical interface to the desired direction angle fired. Top causing epoxy encapsulation of a certain shape, such several roles : protection of cores from the outside world erosion; using different shapes and material properties (Erbium-doped powder or reagent), or diffuse lens with lens functions, Optical control of the divergence angle; Core refractive index associated with the refractive index of air too, Core result of the internal total reflection critical angle is very small, the active layer-only a small part has been removed. the most vulnerable in possession of several core internal reflection and absorption, prone to excessive total reflection optical loss, Selection of the corresponding index for the epoxy transition, manage and out-of-core-efficiency. Constitute a shell for the epoxy resin having a humidity-resistant, insulation, mechanical strength, Core issue of the refractive index and optical transmission rate. Choose a different refractive index of packaging materials, Packaging geometry photon emission efficiency of the impact is different. Luminescence intensity of the angular distribution with Core structure, light output, Packaging lens used and the shape of the material. If using tapered resin lens can focus light LED axis direction, the corresponding Perspective smaller; If the top of the resin lens is round or flat type, the corresponding angle will increase. Under normal circumstances, the LED emission wavelength with temperature changes 0 .2-0.3 nm / ° C, Spectral width increases, the impact of colorful degrees. Moreover, the positive current flows through the pn junction, fever loss helped to cause a rise in temperature in the vicinity of room temperature, the temperature is increased by 1 ° C, LED luminous intensity corresponding to a reduction% Thermal Packaging; maintain color purity and luminous intensity is very important, previously used to reduce its current-driven approach, lower junction temperature. Most of the LED drive current limit in about 20 mA. However, the LED light output over the current increasing, but at present, Many of the Power LED drive current can reach 70 mA, and 100mA even a Grade A. Packaging structure needs to be improved, new LED Packaging Design Concept and low thermal resistance package structure and technology, improve thermal characteristics. For example, using a large area of flip-chip structure, to choose the good thermal conductivity silver plastic, metal stent increases the surface area, Solder Bumps silicon vector directly mounted on heat sink vintage method. In addition, application design, circuit boards and other PCB thermal design, thermal conductivity is also very important. After entering the 21st century, LED efficient, high brightness, panchromatic constant innovation, Hung Hom, Orange LED optical effect has reached 100 Im / W, 501m to the green LED / W, single LED flux reached dozens Im. LED chip and packaging along Gong no longer the traditional design concepts and production patterns in order to increase the light output chip. R & D is not limited to material changes within the volume of impurities, lattice defects and dislocations to enhance internal efficiency, and how to improve management within the core Packaging and structure, enhancing the internal LED emitted photons have the probability to improve photosynthetic efficiency, cooling solutions, Shen light and heat for optimum design, improve optical properties, acceleration of SMD SMT process is the development of the industry mainstream. Packaging products structural types since the 1990s, LED chip and materials production technology and R & D made several breakthroughs, transparent substrate trapezoidal structure, texture surface structure, Flip-chip structure, the commercialization of high brightness (1cd above) red, orange, yellow, green, Blue LED products have asked city, as shown in table 1, 2000 start at a low, China Lumens special lighting were obtained. LED, midstream industry suffered an unprecedented importance to further promote downstream packaging technology and industrial development, Packaging structure using different forms and sizes, different luminescent colors and the color chip, or three-color combinations. producing various series, variety, product specifications. LED Packaging products such as the structure of the type shown in Table 2, under luminous color, chip materials, brightness, size and other characteristics of the classification. Single chip typically constitutes a point source, a number of general-assembly may constitute surface light source and linear light source for information, status indicator and Display, Light Emitting Display is using a number of movements, Core through the appropriate link (including serial and parallel) and the appropriate structure of optical components, constitute a luminous display of light and luminous points. SMT LED will gradually replace the pin-LED, application design more flexible, LED Display in possession of certain market share and accelerate the trend. Solid lighting source some products listed, the future of the LED, long-term direction for development. Compliant pin-foot-LED lead frame packaging used for various Packaging appearance of the pin, was first put on the market successfully developed the packaging structure, numerous species, the higher the degree of technological maturity. Packaging within the structure and reflective layer is constantly improving. LED standard by the majority of customers show that industry is the most convenient and economical solution, Typical LED placement in the traditional can withstand 0.1 W input power encapsulation, its 90% of its energy from the anode pin-distributed to PCB, and then distributed into the air, how to reduce work at the pn junction temperature is Compliant with the application must be considered. Encapsulation material for high temperature curing epoxy resin, its excellent optical properties, process adaptability, high reliability products, will create a transparent colored or colorless and transparent colored or colorless scattering scattering Lens Packaging, different lens shape to form various shapes and sizes, for example, by circular diameter into Φ2mm, Φ3mm. Φ4.4 mm Φ5mm, Φ7mm several species such as epoxy resin copies of the different groups may have different effects of light. Varicolored light source has different packaging structure : ceramic base Epoxy Encapsulation has better temperature performance, pins can bend into the necessary shape, size small; Base metal reflector hood-type plastic packaging is an energy-saving lamp, Power appropriate for instructions; Scintillation ceremony of the CMOS oscillator circuit chip and LED chip portfolio Packaging, may have a strong visual impact of the scintillation light; Dual-from two different luminescent colors of the core composition, Packaging in the same epoxy lens, in addition to color, which may be the third was mixed color, on a large screen display system of extremely broad and may Packaging component color display pieces; constant voltage source to chip LED chip portfolio Packaging can be directly replaced 5-24V voltage of the light. - LED light source is the number of micro-cell adhesion in the PCB location, Reflective plastic box enclosures and epoxy potting formed, PCB design to determine the different Leads arrangement and connection methods, dual-in-line with a separate shooting, and other structural forms. Point-source has been developed hundreds of Packaging, shape and size for marketing and customer application. LED digital display can control or possession meters characters, symbols control, Chen moment many tubes of various products, actual demand by the design into all sorts of shapes and structures. Digital control, with a reflective hood-type, single-chip integrated, single-paragraph 107 of the other three Packaging structure, connections with a total of anode and cathode were two, one is usually said of the digital control, two more commonly known as monitors. Cover with reflection - type fonts, the use of materials for the provincial assembly flexible hybrid characteristics, general with white plastic produced with paragraph 107 of the reflector cavity-shaped shell, to a single LED chip bonding with reflex reflector shield the cavity between seven pairs of PCB-board. Each reflector cavity bottom of the center is to oversee the formation of luminous core areas, with pressure welding wire bonding method. reflex enclosures within the droplet people epoxy resin, and the sticky core of good management of PCB-sticking, and then curing evaporates. Reflex enclosures are divided into air-sealed and sealed it two, the former agent and scattering using dye epoxy resin, used for flats double-device; The latter site filter and absorb beam splitter, and Core floor coated with a transparent plastic insulation, and improve the optical efficiency, generally used for the above four figures. Monolithic Integrated luminous material in the production of a large number of chips in paragraph 107 of the digital display graphics chip, Dicing then separated into single-chip graphics chip, bonding, pressure welding, Packaging zone lens (commonly known as fish-eye lens) casing. Paragraph 107 of the single-good will has produced large area LED chips, is divided into an intron or just-luminescence, so the same seven bond in the digital font Kovar shelves, as pressure welding, epoxy Packaging pose. Single-alone characteristics of the type of micro-miniaturization, it is dual-in-line-package is the most exclusive products. LED Bargraph Display in 106 mm length of the line board. Core placement just 101 (up to 201 just core), high-density packaging, the use of optical refraction theory, make light source through a transparent hood of the 13-15 grating imaging, and the completion of each core simply point to a line from the show, Packaging technology is more complex. Semiconductor pn junction of electroluminescence decision LED mechanism is unlikely to produce continuous spectrum of white light, Meanwhile single LED can not have more than two high brightness monochromatic light only in Packaging, with the help of fluorescent material, blue or UV LED die on the phosphor coating indirect broadband spectrum, synthetic white; or to use several (two or three, multi) made different shade of the core components are encapsulated in a shell, Shade through a mix of white LED. These two methods are practical, Japan in 2000 white LED production reached 100 million. develop into a stable type of white hair products, and the multiple white LED design only assembled in pairs, low flux, partial mainly decorative role, the pursuit of fashion -- the source. SMT Packaging in 2002. Compliant SMT LED (SMD LED) have been gradually accepted by the market, and obtain a certain market share, From pin-Compliant SMD to the entire electronics industry development trend, many manufacturers launched such products. Early use of SMD LED most transparent plastic body with the SOT-23 improved, dimensions 3.04 x 1.11mm, Vol Taping disc packaging containers. In SOT-23, based on research out of the lens with high brightness SMD the SLM-125 series, SLM-245 Series LED, the former monochrome luminescence, the latter three color or two-color luminescent. In recent years, SMD LED development as a hot, a good solution to the brightness, viewing angle, smoothness, reliability, consistency, using lighter PCB and reflective layer material, On display reflective layer of epoxy resin filling needs fewer, and the removal of heavy carbon steel materials pins, by reducing the size, reduce weight, the weight can easily reduce the domestic half, and finally to the application of more perfect, especially for the families, semi-outdoor color display applications. Table 3 indicates that common SMD LED in several sizes, and according to size (with the necessary space) calculated as the concept of the best distance. Thermal pad is an important channel manufacturers of SMD LED data are 4.0 × 4.0 mm pad for the foundation. using reflow pad can be designed with the same pin. Ultra High Brightness LED products available PLCC (Plastic lead with Chip Carrier) -2 Packaging, dimensions of 3.0 × 2.8 mm, the assembly adopted a unique method of high-brightness, Product resistance of 400 K / W, according to CECC way welding, luminescence intensity at 50 mA drive current issued 1,250 mcd. Paragraph 107 of the one-, two, 3 and 4 SMD LED digital display device of the characters .08-12.7 height of 5 mm, Display Size wide choice. PLCC Packaging avoid the pin in paragraph 107 of the digital display and manually insert pin alignment process, with automatic pick-mount equipment production requirements, application design space flexibility, and the bright clarity. Multicolor PLCC packaging with an external reflector can be a simple tube with the luminescence or optical-fiber combination using a reflective replacing the existing transmission-type optical design for large-scale regional provide uniform lighting, the development of 3.5 V, 1A-driven work under conditions of power-Compliant SMD LED. Packaging, power-LED chip and package to develop in the direction of high-power, at the current under large Φ5mmLED than 10-20 times the flux, to be used effectively and not the Thermal Degradation of Packaging Materials - bad solution, therefore, Shell and Packaging, as well as its key technologies, W few can withstand the power LED Packaging has emerged. 5W series of white, green, blue, green and blue LED power from the beginning of 2003 Availability, White LED light output up to 1871 m, the luminous efficiency 44.31 m / W Green bad, develop affordable 10 W power LED, a large tube; ladle size of 2.5 × 2.5 mm, A five in the current work, the light output up to 2001 m, as a solid lighting has ample room for growth. Luxeon Power LED series is A1GalnN power flip-flip-chip with solder in welding Bumps silicon vector, and then completed the Silicon Flip welding heat sink carrier loaded with Shell, the bonding wire for Packaging. Packaging for the admission of such optical efficiency, cooling performance, increase the current density of the design were the best. Its major features are : low thermal resistance, the general was only 14 ° C / W, only a conventional LED / 10; High reliability, Packaging filled internal stability of the Flexible GEL, in -40-120 ° C, not because of the sudden changes of temperature stress, with gold-thread Lead Frame disconnected, and to prevent yellowing epoxy lens, Lead Frame will not be tarnished by oxidation; lens reflex Cup and the best design of the radiation pattern and controllable optical maximum efficiency. In addition, the output optical power, the external quantum efficiency of high performance, solid LED light source developed to a new level. Norlux Series power LED packaging structure of the hexagonal base for aluminum (it is not conductive) Multi-Chip mix Cradle 31.75 mm in diameter, luminescence, at its center position, diameter (0.375 x 25.4) mm, which can accommodate 40 LED chip, the same time as the aluminum heat sink. Core Bond lead on the production base through the two points of contact with the positive and negative connection According to the required output power to determine the size of the base on the top of the core number, can be combined package of ultra-high brightness AlGaInP and AlGaInN core of its launch of monochromatic light. Synthesis of color or white, with the final high refractive index materials by optical design shape encapsulation. Packaging such conventional tube-high-density packaging portfolio, from high-efficiency, low thermal resistance, better protection of the die bonding and fuses, the large current under high light output, is a promising solid LED light source. In this application, will be the Packaging products assembled in a sandwich with aluminum metal-core PCB board. Formation power density LED, PCB as a device connected to the electrode wiring purposes, Aluminum Core dissection can be used for the heat sink, the higher the fat flux and photoelectric conversion efficiency. In addition, the sealed SMD LED small size, flexibility in the portfolio, constitute a module type, Illuminator-condensing type, Reflective and other colorful lighting source. Power LED thermal characteristics of a direct impact on the work of LED temperature, luminous efficiency, emission wavelength, Life, and so on-power LED chip packaging design, manufacturing technology has become particularly important.