The sales of iPhone X turned out to be less than market expectation, so Samsung has lowered the utilization rate of OLED production lines. The tight supply of OLED panels over the past two years has also been eased. According to WitsView, a division of TrendForce, Apple has initiated the trend of OLED panels, and it is estimated that the penetration rate of OLED panels in smartphones will reach 46% by 2021. Mini LED technology is overwhelmed by OLEDs’ technology maturity and competitive costs, so it might be hard for mini LEDs to grow in the smartphone market in short term.
WitsView points out that current supply of OLED panel from Samsung was occupied by iPhones and high-end Samsung smartphones, while the yield rate of other OLED panel makers remains low. As the result, mobile phone vendors have been trying to find alternatives for their flagship models. Mini LED technology is considered a feasible option because it is comparable to OLEDs in terms of high color saturation, high contrast and support to HDR. However, the advantages of OLEDs are more obvious.
OLED can be thin, light and bendable as it does not need backlight
In addition to high color saturation, high contrast and fast response time the biggest advantage of OLED panels is its features of self-emitting and bendable, allowing phone vendors to be more flexible in thickness and appearance design of phones. Mini LED can serve as a transitional product before micro LED technology is fully ready to enter mass production. With the original LCD structure unchanged, the size of LED chips is reduced to 100 to 300 micrometers, and the LEDs are placed in the backlight modules through the matrix arrangement method. In 5.5-inch FHD display, for example, the number of LEDs used is as high as 2000–10,000. Smaller number of LEDs needs longer optical distance, making the devices thicker. The large number of LEDs can reduce the required optical distance and improve the uniformity, making the entire device thinner, but will cause heat dissipation problems and make the cost higher. As present, how to achieve the balance remains the bottleneck for manufacturers.
Mini LEDs should target niche market
From the perspective of costs, OLEDs are more competitive in current stage. Taking a 5.5-inch hard OLED panel as an example, the cost is around $17 to $18; but for a mini LED backlight panel of the same size and the same resolution, the costs may double and reach $35–$40. As the tight OLED supply is being relieved, WitsView believes that the quotes for OLED smartphone panels will be relatively weak in the long-term, the price cuts of LTPS panels will also bring more pressure to mini LEDs. Therefore, it will be difficult for mini LEDs to compete with OLED panels in high-end smartphone market if mini LEDs cannot reduce the costs.
The cost of using mini LEDs in smartphone backlighting depends on the number of LED chips used and the transfer efficiency of wafer. Therefore, many LED manufacturers try to lower the costs through different technical solutions, such as reducing the number of LED chips by optical adjustment or increasing the transfer efficiency of die bond machines to reduce the cost of bonding.
However, in the more profitable niche markets where the gross profits are high, the costs are not a priority for vendors. Therefore, mini LED technology has higher chance of being adopted in niche markets. Current devices using mini LEDs include the 10.1-inch automotive display released by Innolux at the CES 2018, the 27-inch LCD gaming monitor, 15.6-inch notebook and 2-inch VR devices launched by AUO recently, etc. it can be seen that the mini LED technology has more opportunities in niche markets.