We know, the main components of the high power LED
devices for high-power LED chips, manufacturing high quality LED high power chip is critical. Today the Huicong LED screen network to take everyone to work together to understand the common method for manufacturing high-power LED chips which:
1, To increase the size law
By increasing the effective light emitting area and size of single LED, prompting the current flowing through the TCL layers uniformly distributed, in order to achieve the desired luminous flux. However, simply increasing the light-emitting area can not solve the heat problem and the light problem, and not achieve the desired luminous flux and the practical application of the effect.
2, The silicon substrate by flip-chip method
First preparing a large-size LED chip
suitable for eutectic soldering, to simultaneously prepare the corresponding size of the silicon substrate and the silicon substrate to produce for eutectic soldering with a gold conductive layer and leads to the electrically conductive layer (Ultrasonic gold ball pads) , and then use the eutectic soldering device of the large-size LED chip and the silicon substrate are welded together. This structure is more reasonable, considering both the light problem, taking into account the heat problem, which is the current mainstream high power LED production.
American Lumileds, developed in 2001 AlGaInN power flip chip (FCLED) structure, the manufacturing process: First, the thickness of greater than 500A NiAu layer deposited on the top of the p-type GaN epitaxial wafers, used for ohmic contact and back reflector; then using a mask to select the P-type layer and multi-quantum well active layer is etched away, exposing the N-type layer; deposition, etching to form the N-type ohmic contact layer, a chip size of 1mm × 1mm, the P-type ohmic contact is square, N-type ohmic contact to comb inserted therein, so that the current extension distance can be shortened, the spreading resistance is minimized; then flip chip soldering metal bumps AlGaInN having anti-static protection diode (ESD) of the The silicon carrier.
3, The ceramic substrate flip chip method.
First use of the generic device of the LED chip having a suitable eutectic welding electrode structure of the large out of the light area of the LED chip and the corresponding ceramic base plate was prepared, and on the ceramic substrate produced a eutectic soldering conductive layer and leads to the conductive layer, and then using eutectic soldering The equipment will be large-size LED chip and the ceramic substrate are welded together. This structure not only consider the light problems also take into account the heat problem, and ceramic floor for high thermal conductivity ceramic plates, the cooling effect is very ideal, the price is relatively low, so for more suitable substrate material, and may in the future IC integration package reserved space.
4, Sapphire substrate transition law
InGaN chip in accordance with the traditional method of manufacturing a PN junction is grown on a sapphire substrate, sapphire substrate removal, and then connect to the traditional four-membered, material and manufacture of the large size of the blue LED chips
of the upper and lower electrode structures.
5, AlGaInN silicon carbide (SiC), the back of the optical method
Cree Inc., USA is the world's only SiC substrate manufacturing AlGaInN high brightness LED manufacturers, the past few years its production AlGaInN / SiCa chip structure continue to improve brightness and continuously improve. As the P-type and N-type electrode, respectively, located in the bottom and top of the chip, the use of single-wire bonding, better compatibility, ease of use, and thus become another mainstream products of the the AlGaInN LED development.