MicroLED Displays - Intellectual Property Landscape and Analysis 2021

Methodology and terminology 13

Executive summary 26

Introduction to microLED displays 59

Intellectual property in China 74

• Geographic trends in patent applications
• Quality and strength of Chinese IP

MicroLED IP landscape overview 84

• Time evolution of patent applications and publications by: country of filing, company HQ, filing country, company type
• Time evolution of patent applications and publications by: country of filing, company HQ, company type
• Patent applicant ranking, leading players by region, company type
• Analysis by company type (display makers, startup, OEM etc.)

Company analysis 113

• Application ranking evolution since 2017
• Companies’ portfolios – Technology segmentation
• Main applicant ranking and legal status
• Other metrics: Patent portfolio strength index, IP leadership, blocking potential etc.
• IP transfers, main co-owned IP, collaborations and partnerships

Leading Company Overview 137

• BOE
• Samsung: microLED vs. nanorod LEDs (“QNED”)
• LG
• Foxconn Ecosystem (Innolux, Sharp etc)
• TCL-CSOT
• Playnitride
• Visionox
• Facebook
• AU Optronics
• Apple
• Tianma
• X-Celeprint / XDisplay
• Sony
• Konka
• Lumens
• Intel
• Mikro-Mesa
• Vuereal
• Aledia
• eLux
• Top 40 summary: granted, pending and dead patents in each region

Technology segmentation and detailed analysis 168

• Overview of patent families by technology node
• For all upcoming sections: Timeline, portfolio size versus strength index, IP leadership and blocking potential, analysis of recent technology trends, multiple examples of recent patents for each

Transfer and interconnect 172

• Classifications of transfer processes
• Analyses and IP trends per type of process : Elastomer stamps, MEMS, laser, SLM, selfassembly, phase change, films etc.
• Transfer equipment
• Die attach and interconnect
• Die, backplane and pixel architectures to improve transfer and interconnect
• New, unusual techniques

Pixel and display architecture, manufacturing 209

• Hybrids displays
• Chiplets and microsystems
• Thermal management
• Optical multiplexing
• Others: carbon nanotube RDL, multiplexed pixels

Monolithic microdisplays 228

• MicroLED microdisplay manufacturing
• High density interconnect
• Monolithic RGB
• Color in monolithic microdisplays
• Key players, new entrants

Chip design and manufacturing 244

• Improving IQE and light extraction
• Anchor and tethers
• RGB monolithic chips
• Other notable chip structure innovations
• Light extraction, beam shaping, cross talk

Light extraction and beam Shaping 269

• Emerging trends
• Cross talk, external beam shaping

Backplane and display driving 279

• TFT vs. microdriver ICs
• Chiplets and microdrivers, “Smart Pixels”
• PWM and hybrid driving

Defect and yield management, repair, testing and inspection 292

Color generation : native and converted 306

Tiling and narrow bezels 314

Sensors, others 323

• Trends: Touch and pressure, eye tracking, nonspecific, others

Annex: older patents, selection of seminal patents 331

Yole Group of Companies’ presentation 350

AFTER A LATE START, DISPLAY MAKERS NOW STRONGLY DOMINATE IP ACTIVITY

Our micro-Light Emitting Diode (microLED) display report now features close to 9,000 patents from 480 organizations. Most existing display makers were late to the microLED game. Many were initially either dismissive of the technology, or unprepared to tackle its many challenges. Key MicroLED enabling technologies such as mass transfer and LED chips are far from display makers’ traditional core expertise. But in 2014, Apple’s acquisition of Luxvue put microLEDs on the map. Panel makers realized that it could someday become a credible display technology, disrupt the supply chain and challenge their position.

As a result, intellectual property (IP) activity and microLED investment have been increasing exponentially since 2015. All leading consumer electronic companies, panel and LED makers accelerated their microLED development efforts. By 2018, they were joined by equipment makers, material suppliers, and others who, as microLED edges closer to volume manufacturing, are seeing opportunities to serve the industry with dedicated tools and materials.

More recently, microLEDs’ position in leading panel makers’ R&D portfolio and technology roadmaps has started to move from defensive to strategic. Companies that have missed the Organic LED (OLED) opportunity, sometimes limited in their ambitions by the massive capital expenditure requirement or a weak intellectual property position, see in microLED a leveled playing field with a lower entry price.

MicroLEDs could rapidly become the dominant display technology in Augmented Reality (AR) glasses. In most high-volume consumer applications however, the risk that microLEDs will ever fully displace Liquid Crystal Displays (LCD) or even OLED remains low. Nevertheless, microLEDs’ unique features could guarantee a comfortable share in many high-end segments with attractive profitability and become a key income generator.

PANEL MAKER HEAVYWEIGHTS TAKE THE LEAD, BUT STARTUPS AND NEWCOMERS ARE READY TO CHALLENGE

Activity is strongly dominated by Chinese companies, followed by Korea. LG and Samsung made strong showings in 2019 and kept up the pace in 2020 in terms of new applications. Samsung made a remarkable push with more than 130 new patent families, revolving for the most around its Display division’s self-assembled nanorod LED technology, often referred to as Quantum Nanorod Emitting Devices (QNED). The patents show the technology maturing, and a commitment to tackle the challenges associated with moving QNED from the lab to the fab.

CSOT and BOE led patenting activity in 2019 and remained close to the top in 2020. With similar levels, startup PlayNitride, which raised another $50M in 2020 to expand capacity, plays in the same league as leading panel makers and OEMs. Aledia, which moved into a new R&D facility in 2019 and raised close to US$95M in 2020 to build a fab, is also accelerating its IP effort, inching closer to historical leaders such as XDisplay. Panel makers that were missing have now entered our patent corpus including Japan Display, CEC Panda, HKC and Sakai Display.

The field is getting crowded but there is still time for ambitious newcomers to build credible portfolios. In late 2019 and early 2020, Konka and Visionox announced plans to invest $365M and $175M respectively in mini and microLED development and production ramp ups. Konka only filed its first microLED patent in 2019 and Visionox in 2017, but both already have sizable portfolios of pending applications, some showing a surprising level of maturity.

Activity at Apple peaked in 2017. However, the quality and details of new applications shows how far the company’s technology has advanced. The acquisition of Tesoro indicates a focus that is shift or expansion toward enabling volume production rather than fundamental technology development. TSMC, which is expected to be one of Apple’s key partners, appears for the first time in our corpus.

INCREASING TECHNOLOGY MATURITY AND EVOLUTION TOWARD SOLVING MANUFACTURING CHALLENGES

Many recent patents feel “closer to reality”, going deep into details of pixel bank structures and backplanes, or aiming at improving manufacturing efficiency. Detailed analysis shows that most of the IP leaders are moving beyond concepts and lab prototypes and tackling the challenges of bringing microLEDs to mass production. Inventors never seem to run short of new ideas to improve capabilities, cost of ownership, and enable freedom of operation in an increasingly crowded IP landscape.

Growing numbers of applications describe backplanes with testing functionalities, redundancies, and repair management. Efforts to improve small chip efficiency are accelerating on all fronts, including passivation, current confinement, tunnel junctions and plasmon resonance.

New transfer processes keep emerging, exploiting materials’ contraction, expansion, phase changes or surface tension. Polymer stamps still lead, but laser-based transfer dominated activity over the last two to three years. The 2019 comeback of self-assembly was sustained in 2020. Notably, many of LG’s recent applications revolve around a technology ecosystem to enable its fluidic self-assembly process.  Transfer is only the first step. With bonding pad sizes and gaps shrinking below 5 µm, die interconnects are challenging at microLED scale. Effort on this issue is therefore accelerating.

Growing the three emitter colors on the same wafer is also a hot area. Pixel chiplets that integrate emitters and driving circuits into a microsystem with redistribution layers are on the rise. For AR or light field, optical multiplexing is an intriguing option worth monitoring.

Acer, AGC, Aledia, ANK, Aoshi, Apple/Luxvue, Applied Materials, Appotronics, APT, ASTI, AU OPTRONICS, BOE, CEA, CEC Panda, Central South University, Century Display, Changelight, HKC, CIOMP, Comptek, Cooledge, Corning, Cree, Dai Nippon Printing, Elux, EPilight, EPistar, Erised, Facebook/Oculus, Foxconn, Fuzhou University, General Interface Solution, GLO, Globalfoundries, Goertek, Google/X Development, Guangdong U.  of Technology, Gwangju Inst.  of Science & Tech., HC Semitek, HCP Technology, Himax, HiSense, HKC, HKUST, HP, Huawei, Huazhong U. of Science & Tech., IBM, IMEC, Innolux, Intel, ITRI, Jade Bird Display, Japan Display, Kaist, Kimm, Konka, Kookmin University, Kopti, Korea Advanced Nano Fab Center, Kyocera, LG, Lightizer, Longli Tech., Lumens, Lumileds, Luxnour Technology, Mikro Mesa, MTC,  Nanchang University, Nanjing University, Nationstar, Nichia, Nitto Denko, Nthdegree, Optovate, Osram, Ostendo, PlayNitride, Plessey, Point Engineering, Prilit Optronics, PSI Corp, Qisda, QMC, Rohinni, Raxium, Sakai Display, Samsung, Sanan, Seoul Semiconductor, Seoul Viosys, Sharp, Shineon, Siphoton, Sitan Technology, Sony, Sun Yat-Sen University, SUSTECH, Syndiant, TCL,  TCL-CSOT,  Terecircuits, Tianma, Toray Engineering, Tsinghua University, Ultra Display Technology, Unimicron, U. of California, U. of Hong Kong, V Technology, Visionox, Vitrolight, Vuereal, X-Celeprint/X-Display, Xiamen U. of Technoloy, and more.