led封装工艺流程(国外英文资料).doc
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led封装工艺流程(国外英文资料)
LED process flowchart (revolution)
LED packaging
LED packaging technology is developed and evolved on the basis of discrete device packaging technology, but it is very special. In general, the core of the discrete device is sealed inside the package, which is mainly to protect the core and complete the electrical interconnection. And LED encapsulation is completed the output electric signal, protection tube core work, output: the function of visible light, both the electric parameters, and the optical parameters of design and technical requirements, cannot simply be discrete device packaging for the LED.
The core of the LED light-emitting part is composed of p-type and n-type semiconductor pn junction tube core, when the minority carrier injection pn junction with majority carrier compound, can emit visible light, ultraviolet light or near-infrared light. But p-n junction area of photons is directional, to launch the same chance in all directions, therefore, not all of the light tube core can be released, the quality depends mainly on semiconductor materials, the sealed tube core structure and geometric shape, structure and coating materials, application for higher internal and external quantum efficiency of leds. Conventional Φ type 5 mm LED encapsulation is the side length of 0.25 mm square tube core bonding or sintering in lead frame, the positive by the spherical contact point of the tube core with gold, within the bonded to lead connected to a tube feet, the cathode through reflection cup and wire rack connected to another pin, and then the top with epoxy resin coating. The reflection cup is used to collect the light from the side of the tube core and the light from the interface. There are several types of epoxy resins that are sealed in the top, which can be used to protect the core of the tube from the outside. The use of different shapes and properties of materials (admixture or non-dispersing agent), the function of lens or diffusing lens
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