(a) flip chip type LED chip package
In addition to the vertical type chip, flip chip type chip is the industry to the development target. The production of flip chip chip relatively vertical structure is simple and can avoid many, complex process, make the production feasibility of substantial increase, coupled with the back end chip technology of gold finger and the through hole technology mature auxiliary, solid crystal former must plant a plurality of ball into a large area P, N electrodes directly adhesive bracket, collocation eutectic solid crystal, greatly simplifies the technical threshold, flip chip packaging and packaging heat dissipation path, shortened, compared to the horizontal type chip has better heat dissipation capability, driving voltage can also be down, in the future energy saving and carbon reduction drive, flip chip packaging is a solution very good.
Based on the consideration of the package, the main package technology currently used for fluorescent powder coating and transfer process. Fluorescent coating is billion light development technology, is mainly covered by a thin layer of fluorescent layer on the chip, so can greatly improve the luminous efficiency of assembly, currently billion light has this product with high power element.
Transfer process technology was originally used mount type products in the small surface was a great success, and further apply this technology in high power machines, overcomes the silicon molding and mold sticking technology problem, because of the current TV backlight module power promotion and reliability requirements, PPA reflection plate of traditional crushing for organic materials, not like silicon or resin provides heat and light better, in order to effectively improve the reliability, plans to use this transfer process technology used in a backlight assembly products.
On the package size, can now reach a minimum of high power package size is 3 x 3.0mm, or even less than 2 * 2.0mm sample preparation, however the most common specifications are still commercially available is 3.5 * 3.5mm products, this product application surface is very wide, therefore, glabrous to open the pioneer molecular billion solid state lighting era, photoelectron billion will continue to apply small size and high power technology in the products, aluminum nitride ceramic substrates with low cost with high reflectivity mirrors the implementation, making the product package support required, in addition and technology applications of eutectic solid crystal, through the metal will be fast heat from the centre of LED oriented high thermal conductivity aluminum nitride ceramics, in order to reduce the operating temperature of LED components, to achieve high efficiency (150lm/w), high power (3-5W operation), long life, low energy consumption (60000hrs) of the LED product performance.
The cost and reduce the quality improvement of chip selection and global quality partners committed to existing chip, and the rapid development of new chip structure, in order to with the minimum cost of mass production of silicone pressure molding technology, reduce the existing LED chip technology package into the optical structure design, and to meet the rapid reaction effect of light from a new design of chip structure, to achieve the lowest cost, highest production efficiency of the design goals.
(two) above 20W LED package
In the LED package, COB package technology is another key, 10W following LED is not applicable to COB packaging technology, the mainstream of the field still using single power package form; more than 20W LED is suitable for the use of COB packaging technology. At present, Japan LED bulb lamp market mainly converted to polycrystalline COB encapsulation, traditional power chip and module for most of the MR16 pointing to the LED light source.
The COB packaging with more is aluminum plate, copper substrate and ceramic substrate. The coefficient of thermal conductivity of each of the different materials, lead to differences in the thermal properties, such as thermal conductivity of diamond is 1000, followed by the silver and copper is about 400, and aluminum is more than 100, and the coefficient of thermal conductivity of ceramic in the range of 8-22. In an insulating material, thermal conductivity of ceramic is good, and inexpensive price, so many package options using the ceramic substrate.
(three) high voltage LED package
In addition to high power LED, high pressure LED package is also a key. Packaging products of high voltage LED across 1W, 2W and 4W of the product market, and high product, is in a new thinking to solve the solid state lighting excess energy loss is caused due to step-down circuit problems, and then help to end consumers reduce the purchase cost. At the same time, due to the high voltage LED chip itself with the sapphire substrate, chip lateral light as a more general strong, so in the package should be adopted when the full angle phi fluorescent powder coating uniform design, in order to package in full view the role of temperature consistent, quality and enhance light.
Key encapsulation technology of high voltage LED products is the continuation of the advantages mentioned above, in addition should provide consumers with more convenience, so that different regions in the voltage under different operating conditions, can be used for fast and convenient. For example, photoelectron billion launched 4W products, can be directly used circuit board circuit of series parallel design to meet the global 110V and 220V voltage source demand. And because the voltage of single component package body cross pressure up to 110V, what 220V, so in the development of high voltage LED package, photoelectron billion insist on ceramic substrate package used in the form of insulation, in order to reduce the risk of small size between the positive and negative electrode spark discharge.
