Major Boost to PMOLED Lifetime and Reliability: Design Guidelines

OLED displays have gained traction across multiple industries due to their superior image quality, high contrast ratio, wide viewing angles, and low power consumption. 

Recent advancements in PMOLED technology have significantly improved their lifetime and reliability through better materials and processes. 

Initially, PMOLEDs faced rapid degradation from exposure to oxygen, moisture, thermal, and electrical stress, limiting their operational lifetime to 20,000 hours.

However, new materials and manufacturing processes have dramatically increased their longevity, making PMOLEDs viable for industrial applications.

Designing a new product using PMOLED technology requires careful consideration of various factors to ensure best performance and reliability.

How has this been achieved?

Material Innovation:

• High purity organic materials: reduced pixel ageing and colour shift
• Stable blue emitters: Improved stability of blue emitters to match red and green

Encapsulation Techniques:

• Low water permeability UV adhesives: isolated from moisture and oxygen
• Liquid desiccant: enhanced environmental resistance

Thermal and Electrical Management:

• Thermal dissipation: new materials and designs for effective heat dissipation
• Current regulation: constant current with reduced thermal and electrical stress

Enhanced Driving Algorithms:

• Optimised driving algorithms, including current modulation and pixel compensation techniques to mitigate issues such as image retention and burn-in, which affect longevity and uniformity
• Dynamically adjusting driving parameters in the design to achieve uniform ageing across the display and thus prolonging its operational life.

Reliability Tests

To validate the operational lifetime of PMOLED displays, rigorous testing which include environmental stressors and simulated operating conditions are utilised to assess the robustness of the technology

• Temperature and humidity: Cycling tests are done simultaneously to simulate real-world operating conditions encountered in industrial settings.
  
• Lifetime: Accelerated testing subject PMOLED displays to continuous operation under elevated temperatures and high brightness levels. Analysis of degradation parameters provide information for performance improvements and determine lifespan durability.
  
• Vibration and mechanical stress: Over-stress testing ensure reliable operation in real-world harsh environments

Selecting the right PMOLED manufacturer

• Technological capabilities: Assess advancements in material science, encapsulation, and thermal management. Ensure competent R&D team dedicated to continuous advancement of PMOLED technology.
  
• Quality assurance and reliability: Ensure stringent quality assurance and control with accelerated lifetime testing to predict long-term performance
  
• Customisation and support: options specific to the end-product requirements and strong technical support across the full life cycle of the product including design, development, manufacturing, quality and reliability
  
• Material Selection: Choosing the right material to manage heat more effectively, coupled with improved encapsulation materials and techniques to keep oxygen and moisture from entering the organic layers.
  
• Source from reliable suppliers known for high quality and consistency.

Design Guidelines for Engineers

Designing a new product using PMOLED technology requires careful consideration of various factors to ensure best performance and reliability

• Enclosure Design: Appropriate enclosure design is essential to protect PMOLED displays from environmental contaminants. Sealed moisture resistant enclosure with effective ventilation is essential.
  
• Thermal Management: Efficient thermal management is critical to prevent overheating and performance degradation. Heatsinks, thermal pads and cooling solutions may need to be integrated into the design
  

• Power Management:
  • Voltage regulation: PMOLED requires stable power sources with precise voltage regulated to ensure uniform brightness and prevent overdriving, which accelerates pixel degradation and reduces lifespan. Design engineers should integrate voltage regulators or DC-DC converters to provide clean and regulated power to the display.
  • Current Limiting: Implementing current limiting circuits or resistors help protect display from excessive current flow, prevent thermal stress and premature failure. By limiting current levels within safe operating ranges, you can improve the reliability and longevity.
  • Power Saving Modes: Leveraging power saving routines such as dimming, or sleep mode can significantly reduce power consumption during idle or inactive periods. Design engineers can incorporate software control power management features to dynamically adjust brightness, also implementing algorithms to shift display content periodically, distributing wear evenly across the display and preventing burn-in.
  • Adjust brightness based on environmental conditions to reduce overall stress on the display.
• Interface Compatibility: Selecting the appropriate interface such as SPI or I2C, is essential for seamless integration of PMOLED displays. Compatibility with existing microcontrollers and communication protocols simplifies system design and integration.
• EMI Shielding: Incorporate EMI shielding measures such as conductive coatings and ferrite beads to help minimise interference and ensure reliable operation.

If you want to explore how these advancements in PMOLED technology can have an impact on your industrial design, contact Anders today.