Mar 14, 2017: Despite significant increase in LED adoption across the globe, leading to widespread installations of LED projects like street lighting, and other government projects, besides, expanded uses in hospitality, retail commercial and industrial applications, the cost of LED lighting is still higher than the conventional lights, primarily due to high cost of components. However, new chip architectures and phosphor techniques can provide several benefits and help in bringing down manufacturing costs.
Advanced packaging technologies like flip-chip and new phosphor techniques are changing the landscape of the LED industry because solution clearly reduce the number of manufacturing steps. For example, some LED chip manufacturers, by using flip-chip process can supply their products to the LED module manufacturers directly.
In 2013, flip-chip LED represented only 11% of the total high power LED packaging. But, the industry expects it to reach 34% by 2020. Flip-chip LED will take market share from vertical LED that will represent 27% of the total high power LED packages market by 2020.
Steps taken to reduce LED price
The increased demand for LED lighting is developing pressure on the industry to produce improved quality products, yet at a lower cost. Manufacturers are, therefore, reducing manufacturing complexity and trying to make the supply chain simple.
Advanced chip fabrication techniques: Also, in response to this pressure from the consumers, the industry is developing more advanced LED manufacturing technologies, particularly with respect to chip fabrication techniques, and to start with by developing improved process engineering; more advanced semiconductor capital equipment; and advanced LED materials.
Efficient phosphor materials: The industry is developing more efficient and rugged phosphor materials that can ensure reduced manufacturing cost and ensure improved light quality while reducing complexity.
Phosphors are now being manufactured into polymer film sheets or glass tiles, which are pre-formed. Manufacturers are also using optical-ceramic materials, and applying them directly on the surface of the LED chips from where light is emitted. These innovative manufacturing technologies will enable wafer-level packaging of LED chips. Industry experts believe that wafer-level packaging will help to lower chip manufacturing costs as redundant packaging steps will be eliminated, yet, LED chip reliability, efficacy and quality will be further improved.
These advanced technologies, when combined with advanced manufacturing processes, can also eliminate binning, which means systematic distribution of performance parameters like flux, wavelength or CCT, and Vf into small groupings that may optimise assembly performance.
These manufacturing techniques are still being tested on flip-chip LED architectures. For example, Samsung?s flip-chip LED has a uniform light-emitting surface. The flip-chip architecture provides a better light-emitting surface than the conventional chip architecture. The flip-chip architecture also helps to implement new phosphor technique easily.
Advantages of flip-chips
Realising the advantages of flip-chips, manufacturers are adopting them as they have several advantages, the most important being simplifying design and manufacturing.
First, as the electrical contacts are at the bottom, the wire-bonds to connect with the electrical contacts on the top of an LED can be eliminated, which means a full manufacturing step has been cut down. Moreover, wires are usually the failure point, which is also done away with.
Flip-chips process also improve efficiency of the chip. As there are no electrical contacts, there is more chip surface and hence more light can be emitted. This larger chip surface helps the phosphor materials to be put on the top of the chip.
With flip-chip process, phosphor pre-forms that are manufactured in polymer or glass sheets, can achieve uniformity standards within 1 SDCM.
If packaging is done at the wafer-level, it helps to lowe manufacturing cost because this technique offers several benefits. Many manufacturers are moving in this direction for more low cost, efficacy and uniformity. Industry experts believe that this technique will take the manufacturers to new levels of manufacturing efficiency, where binning can be reduced or totally eliminated. Binning is a time-consuming and costly process. It also doesn?t guarantee full efficiency.