Why Pay Attention to LCD Screen White Spot?
In industrial equipment, medical devices, smart energy systems, and transportation terminals, the reliability of LCD modules directly affects product delivery and brand reputation.
Even a seemingly minor defect such as an LCD screen white spot (white dots) may lead to product rejection, failure, or complaints. The key is how to eliminate white dots on LCD screen before shipment.
Common Causes of LCD Screen White Spot in Manufacturing
Based on industry experience, white spot on LCD defects usually come from:
- Voltage/driver instability: Appears as local bright spots during electrical testing.
- Uneven backlight module: Leads to bright white spot or blotchy white spots on LCD screen.
- Cell defects: Uneven liquid crystal distribution or alignment layer issues.
- ESD damage: Improper handling or testing causes permanent white dots.
- Bonding/assembly issues: Air bubbles or contamination in optical bonding lead to visible spots.
These are not random issues but can be controlled through strict quality inspection.
Can white dots on LCD screen Be Repaired?
- Repairable cases: Surface contamination or bonding bubbles → can be resolved by rework.
- Non-repairable cases: LCD cell defects, backlight problems, or ESD damage → usually require module replacement.
Thus, whether repair is possible depends on the source of the defect.
How to Prevent White Spot Problems？
Manufacturing Solutions
- Improve testing precision, add high-voltage and aging tests.
- Maintain strict cleanroom management to reduce contamination.
- Optimize optical bonding to avoid bubbles and unevenness.
- Strengthen ESD protection to reduce potential damage.
Usage Recommendations
- Avoid long-term exposure to high temperature or humidity.
- Prevent external pressure on the screen surface.
- Choose LCD modules that have undergone strict testing and reliability validation.
MAXEN's Strict QC to Control LCD Screen White Spot Defects
- Incoming Quality Control (IQC)
Strict inspection of glass substrates, backlights, ICs, and FPCs to ensure compliance with specifications.
- In-Process Quality Control (IPQC)
Multi-point checks during COG/FOG bonding, backlight assembly, and optical bonding to monitor stability and detect defects in real time.
- Final Quality Control (FQC)
Comprehensive inspection of LCD/touch modules:
- Appearance check: No stains, scratches, or bubbles.
- Function test: Lighting test to detect bright/dark/white spot issues.
- Performance sampling: Color uniformity, response speed, brightness stability.
- Aging Test
Continuous operation 2 to 4 hours under high temperature and humidity to verify stability and reliability, screening out potential white spot problems.
- Outgoing Quality Control (OQC)
Final inspection before packaging, ensuring only qualified products are shipped.
Customized Testing and Service Capabilities
In addition to standard testing, MAXEN offers tailored solutions:
- Extended electrical testing → Supports special voltages, interfaces, and signal conditions.
- Customized reliability validation → High/low temperature cycling, vibration, humidity stress, etc.
- Application-specific shipment standards → Stricter acceptance criteria for medical, energy, or industrial control applications.
Conclusion: Quality Starts with Testing, Differentiation Comes from Control
In the display industry, LCD screen white spot is a common defect. Most suppliers implement IQC, IPQC, FQC, and OQC, but often rely heavily on sampling, have insufficient aging tests, and lack customization.
What makes MAXEN different
- 100% electrical and lighting inspection → Unlike industry sampling, every module is tested.
- Enhanced aging test → Long-term operation under high temperature and humidity to expose hidden defects.
- Customized electrical testing → Support for specific voltages, interfaces, and signal conditions.
- Application-based shipment standards → Stricter acceptance criteria for medical, energy, and industrial use cases.
- Full traceability → Complete test records to support audits and certification.
Choosing MAXEN means gaining more rigorous testing, more reliable quality, and more controlled delivery.
Through 100% lighting inspection, enhanced aging tests, and customized reliability validation, we ensure every LCD module meets application requirements.
Want to learn more? Contact our team at at sales@maxen-lcddisplay.com.
