(1) High-power LED Lighting chip
High-power LED lighting-class LED chip development, upstream chip factories in Taiwan has started in 2010, the sapphire substrate side light from the original level of the electrode chip, into the opaque metal or other conductive silicon substrate of the vertical electrodes, and through through the process to increase light extraction efficiency of light efficiency tricks. Almost vertical by the positive electrode chip out of the light, the LED Tube package designed to simplify the structure design to achieve good optical performance, and both better heat dissipation, current distribution and low drive voltage. The relationship between the patented design to avoid the current level of electrode manufacturers have developed a chip, but opaque substrate in order to achieve the same effect. In addition to light-emitting chips, the current is also actively developing various white chip POC (Phosphor On Chip) technology, the chip level to complete wavelength conversion to the chip itself is white and is a point source, the package design and performance than the traditional dispensing white LED has advantages. However, manufacturing yield issues are still to be overcome.
(2) High-power LED thermal substrate
Taiwan LED Display cooling downstream substrates have a number of market makers in 2010 to join the majority of passive components factory. Cooling of high power LED package substrate addition to the traditional metal stents with plastic injection, the current ceramic substrate also beginning to be widely used. Compared with metallic stents with plastic injection molding, ceramic substrate material properties with reliability, stability and features a long, high-power operation to highlight its advantages. Early high-temperature co-fired ceramic substrate to be printed and die thickness, in the manufacturing cost, yield and product cost performance is not a competitive advantage. Ceramic substrate using the current lithography process of direct copper film substrate DPC (Direct Plating Copper), temperature and low manufacturing cost, high line resolution and alignment accuracy and better dimensional stability and heat dissipation characteristics, can be that is most suitable for high power and small size of the development of heat LED substrate. Although the price is still several times higher than the metal stent, but in each race to put the situation, the price will speed up the pace.
(3) AC LED
Since the AC LED Application Research Alliance in October 2008 inception, has been gradually integrated industry resources and accelerating the AC LED industry, but also successfully promote AC LED downlight CIE International Organization for Standardization standard addition, the AC LED measurement standard into TC2-63 content of the draft in the AC LED Standard International. AC LED is can be AC (110V/220V) driven by external transformer or rectifier without the LED, the circuit can effectively reduce the cost and reduced by 15% to 30% of the power conversion loss, high voltage and low current is also reduced circuit transmission losses. Making use of AC LED wafer manufacturing technology, a single grain split into multiple pieces on a separate micro-electric crystal, and then the formation of micro-grain loop cascaded with each other, in the grain size, grain number and the micro-loop mode aspects through the design and analysis, to meet the actual demand. From the application point of view, lighting, AC LED spotlight does not require complicated electronic components and circuit design, lighting design space more flexible. From LED’s point of view, AC LED DC LED is not only compatible with the grain processing technology is easy to mass production through its dual mode of the wizard can also avoid ESD problems, but not as its brightness DC LED, and the light source in the power supply is not stable under the flickering problem to be overcome. The current AC LED package may be speaking in the third quarter of 80lm / W, in the 3W ~ 10W of DC LED lighting applications, and compared with the price advantage.
(4) HV LED (High-Voltage-LED)
And AC LED compared, HV LED is to recover only single voltage DC LED luminous efficiency AC LED driver and the DC LED lower than the shortcomings of the solutions derived from its series of semiconductor process from dozens of micro grain. The HV LED with AC LED rectifier circuit that functions with the same, and provide constant light when a higher luminous efficiency, but also can be used in high-voltage DC powered lighting market. HV LED current efficiency higher than the AC LED bulb 20%, the future is expected to reduce the cool white and warm white light from the target in 2015 150lm / W.
(5) COB (Chip-on-Board)
Compared with those in POB (Package-on-Board) package, Taiwan manufacturers in the COB has introduced new technology fields. COB is directly encapsulated in multiple-chip metal-based printed circuit board MCPCB, with the advantage of reducing the heat resistance and high optical density higher packaging density and the characteristics of the thin low-cost high-power LED package demand and cost , convenience and design of diverse applications and other advantages, LED strip has now been widely adopted to replace the traditional multi-chip package LED stars, together with the RGB chip package can also be mixed with the better light uniformity. Ceramic substrate due to the lock screw in the bulb when the cracking of substrates used in the current multi-COB has progressed to the MCPCB, and the dielectric layer MCPCB thermal performance progress, is expected to become the market mainstream.
But an optical lens COB in reducing the multiple refraction of light caused by the increase in terms of heat loss and yet to improve, and the substrate to enhance the production yield has yet to be, these are the industry desperately wants to resolve the issue.
(6) WLP (Wafer-level-packaging)
Compared to the metal bracket and ceramic substrate, a semiconductor silicon substrate board to do is heat LED panel manufacturers in Taiwan in recent years, another research direction. Package substrate to make silicon wafers in the process there will be the cost advantage of high density packaging, and reliability in the heat also has a certain level. The future and moving toward the development of a true wafer level packaging, replaced with a solid crystal semiconductor wire bonding process, and integration of many different features on the wafer die, as SoC (System on Chip) LED.
January 25th, 2011
LED packageLED Lighting, by led.
(1) High-power LED Lighting chip