Used first in smartphone flashes, chip scale packaging (CSP) LEDs add value through power density offered from a small surface. As smartphones get thinner and add functions, so too must integrated components/modules. The small form factor and wide beam angle of CSP LEDs have also driven their use in TV backlighting units. Wide beam angles mean the pitch between LEDs can be larger, reducing the number of devices needed and in turn lowering backlight cost.

However, CSP LEDs are also a means to develop new functions in lighting products and this will be the next growth driver for such LED device, according to the new CSP LED Lighting Module report by Yole Développement and PISEO, both part of the Yole Group.

Some general lighting applications are likely to adopt these light sources to reduce the cost of the full system (lamp and/or luminaire). Their small size enables LED clusters, similar to COB LED modules but with more functionalities. CSP LED clusters promise tuneable, white and HCL intended to promote a person’s well-being, mood and health, and others smart lighting functions. At middle term, such device will also help the development of AFLS.

cspledlighting_marketrevenue_yole_201703 (cr) Figure 1: Yole and PISEO forecast a CSP LED market share of nearly 6% by 2021. (Source: Yole Développement.)  

“We estimate that CSP LED modules represented less than 1% of the LED module business in 2016,” said Pierrick Boulay, Market & Technology analyst at Yole Développement. “However, with strong potential in multiple applications and the lighting industry getting experience with integrating such technology, we forecast a market share of nearly 6% by 2021.”

The CSP LED Lighting Module report also pointed out several challenges to overcome at the device manufacturing and module integration levels. These include colour uniformity, chemical stability, given there is little to no sealing off from the external environment, and control of optical properties like the radiation pattern.

Samsung has made several strategic technical choices, including CSP manufacturing process to perform a LED device with a very competitive manufacturing cost.

cspledlighting_applicationslandscape_yole_201703 (cr) Figure 2: The application landscape shows Samsung's strategic technical choices. (Source: Yole Développement.)  

Chip-scale packages are new to the LED industry, according to Yole, but they are the mainstay of the traditional semiconductor industry, where they improve reliability, thermal management and enable smaller packages.

"CSP LEDs can be less than a tenth of the size of high and middle power LEDs, increasing lumen density and simplifying integration into final products," said Dr. Olivier Andrieu, R&D project director and system architect at PISEO. ”This new architecture also provides a lower thermal resistance, reporting reliability aspects on PCB level and solder management, and widen viewing angles compared to other traditional packages."

cspledlighting_manufacturingchain_yole_201703 (cr) Figure 3: A comparison of manufacturing chains of the COB and CSP processes. (Source: Yole Développement.)  

The market researcher's report points out several challenges that still need to be overcome at the device manufacturing and module integration levels. These include colour uniformity, chemical stability, given there is little to no sealing off from the external environment, and control of optical properties like the radiation pattern.