The display industry is currently undergoing the most significant manufacturing and display technology changes since flat-panel display (FPD) production became widespread in the 1990s. A key change is the integration of key components into panels, which paves the way for advances in display form factors and performance.
For much of FPD history, amorphous silicon (a‑Si)-based LCD cells utilizing 3.5-micron (µm) line-and-space (L/S) photolithography were the means in assembling discrete components-such as backlights, driver ICs, circuit boards, connectors, and polarizers-into completed display modules, which were then sold to panel makers.
This manufacturing and business model evolved, accelerating around 2010 because of various reasons. Among them were the rapid growth of smartphones, the commercialization of AMOLED displays, the rise in demand for better image quality, and the intensifying competition among panel makers. In turn, smartphones drove the expansion of the display panel business to IT and TV applications.
Today, a slightly different set of forces in manufacturing technology is at work in advancing and driving change in the FPD market. These include:
- Improved photolithography to 1.5 µm L/S
- High-efficacy and long-lifetime AMOLED materials
- Innovative equipment and processes
- High-mobility oxide and low-temperature polysilicon (LTPS) semiconductors
- New materials, such as quantum dots (QD) and high-temperature-resistant polyimide.
With these new enabling forces, abundant leaps in production technology have become possible, giving rise to remarkable results that now benefit consumers: for instance, incredibly thin, light, and borderless full-screen displays; rigid and flexible AMOLEDs alike tailored for specific applications; resolutions of 500-600 ppi that are now commonplace; and features like DCI-P3 wide color gamut and very high contrast.
Many more new production technologies and display applications are in development, including those that will extend form factor and performance benefits. Many also relate to facilitating foldable displays, and will continue the shift from transmissive to emissive AMOLEDs or photo-emissive and electroluminescent QDs. Other advances have to do with integrating into the display panel discrete components, such as the color filter, cover lens, drivers, light source, polarizer, and touch sensor.
Component integration, therefore, is not new, singular, or complete, but is closely linked to important display manufacturing advances. Most notably, these advances include a reduction in the critical dimension of the large-area photolithography to achieve high resolution, as well as semiconductor technology advances in oxide, LTPS TFT, AMOLED and QD.
These findings and other details can be found in the current IHS Markit AMOLED and LCD Supply Demand & Equipment Tracker.
Benefits of component integration
Component integration is part of the shift in how FPDs are now manufactured and used. Depending on the type of display, the technologies that are related and the application involved, the amount of integration called for will vary. Discrete components, however, will likely remain part of the display module always.
Component integration delivers two primary benefits:
- Enhanced form factors, such as narrow borders, reduced thickness and weight, and conformable displays
- Improved optical performance, such as wider color gamut, increased brightness and contrast, reduced response time, and enhanced viewing angles
The following table illustrates current component-to-panel integration trends, benefits, and development status. It also shows components being integrated into LCD and AMOLED panels for mobile, IT, and TV applications.
As illustrated, touch sensor and polarizer integration can improve transmission and brightness, but most of the benefits in optical performance relate to enhancing the performance of color filters, through the use of quantum dots or via the larger trend of replacing LCD color filters and backlights with AMOLED (and potentially QD) emitters.
Nonetheless, LCD technology remains a solid and reliable technology, having improved dramatically in the last 20 years. And with a considerable cost advantage over OLED, LCD is unlikely to disappear soon.
Self-emissive display technologies, do possess, however, a fundamental optical performance advantage. This advantage will help drive total AMOLED areal panel demand at a 24% compound annual growth rate between 2017 and 2024, as we predicted in the OLED Display Market Tracker. In comparison, LCD areal demand is forecast to grow on average at 4% per year over the same period.
Driver integration, along with many other design and component innovations, has facilitated borderless, thinner, and non-conventionally shaped LCD modules. Even so, AMOLED allows and benefits most from component integration. This is true for both image quality and form factor. Many very thin, light, and even curved AMOLED-based devices have already been commercialized.
Fewer layers in the display stack and no backlights enable the production of flexible AMOLED. Increasing flexibility and the ability to roll and fold displays are well into development, with first products forecast to reach the market in 2018.
For foldable displays, component integration to reduce panel thickness and layers is critical to minimize bending radius and to prevent display failure from defects and delamination. Thicker displays are more difficult to fold and more likely to generate creasing defects.
The more layers used in the display stack, the more challenging it is to keep them laminated together when folding. For this reason, and to realize the goal of truly foldable displays, panel makers continue to push component integration, targeting less than 0.5 mm total thickness with 1.0 mm bending radius within the next few years, shown below, and as we reported in the AMOLED & Flexible Display Intelligence Service .
Fully flexible displays can potentially enable new applications, such as foldable, wearable, advanced automotive, and wallpaper-like FPDs. Such new applications are of great interest to both the display industry and consumers because they can expand the display market and multiply the ways people interact with information.
Since integration transfers third-party component production to panel fabrication, it tends to complicate manufacturing processes. In many cases, this will increase capital costs and make building new FPD factories more expensive. Regardless, the decrease in the number of discrete components can reduce total display cost, with the important caveat that high yield rates are maintained.
As integration increases, it shifts more value from components into the panel. This creates an opportunity for panel makers with leading-edge component integration technology and robust manufacturing processes to differentiate products and increase profitability.
As we reported in the IHS Markit Display Materials & Components category of the Displays research service, the FPD industry is undergoing unprecedented change that includes the rapid increase in display resolution, the proliferation of semiconductor technologies, a shift from transmissive to emissive displays, and from fixed-form, rigid displays to flexible, conformable, and foldable displays. Many of these advances are enabled by integrating discrete components into the panel to improve optical performance or form factor.
Integration is particularly important for enabling highly flexible and foldable FPDs. In turn, foldable is considered one of the most important developments in the display industry, as it can widen the application scope, increase average sizes of displays used in mobile applications, and create new ways for consumers to interact with information. Many integration-related technologies are proprietary and difficult to implement. Technical challenges related to integration can increase risk, but integration offers panel makers and their enabling suppliers a chance to increase competitiveness and differentiate their products.
David Hsieh is Research & Analysis Director within the IHS Technology Group at IHS Markit
Posted 18 July 2018