LED packaging manufacturers often receive customer complaints when supplying products for displays (especially LED displays, outdoor large screens, TV backlights, etc.). These complaints can be broadly categorized into four areas: performance, reliability, appearance, and logistics/service.
Below is a detailed list of common complaints and their possible causes:
1. Performance Complaints
Insufficient or Uneven Brightness
Customers find that the overall brightness of the display screen is below standard, or that the brightness varies in different areas.
Possible causes:
Insufficient luminous efficiency of the LED chip.
Unreasonable packaging lens design leading to light decay or uneven light distribution angle.
Uneven BIN grading or mixing of LEDs with different brightness levels.
Color Temperature/Color Deviation
The screen appears reddish, greenish, or has inconsistent colors.
Possible causes:
Inaccurate control of LED luminous color temperature.
Poor matching of RGB or dual-color LEDs.
Yellowing or aging of packaging materials.
Electrical Performance Problems
Inconsistent forward voltage, abnormal driving current.
Possible causes:
Unstable quality of LED chips or bonding wires.
Packaging process leading to high thermal resistance and uneven current distribution.
2. Reliability Complaints
Rapid Light Decay
LED brightness decreases rapidly over time.
Possible causes:
Poor thermal stability of packaging materials.
Poor heat dissipation of bonding wires or chips.
Operating environment temperature or humidity exceeding design parameters.
Black Spots/Dead Pixels
Dark spots or non-illuminated points appear on the screen after a period of use.
Possible causes:
LED chip defects.
ESD (electrostatic discharge) damage.
Poor soldering, packaging cracks.
Packaging/Soldering Failure
Yellowing or detachment of the encapsulant, cracked solder joints.
Possible causes:
Incompatibility of packaging materials with PCB or driver.
Excessive stress from thermal cycling or humid environments.
3. Appearance Complaints
Surface Defects
Black spots, bubbles, or scratches on the LED surface.
Cause: Poor packaging process, insufficient cleanliness.
Packaging Size Deviation
Difficulty in inserting into the PCB or poor soldering.
Cause: Low mold precision, lax process control.
Inconsistent Light Emission Angle
The screen displays bright and dark spots or light patches.
Cause: Lens position deviation or uneven packaging design.
4. Logistics/Service Related Complaints
Delivery Delays
Affecting display screen production plans. Packaging Damage
LEDs damaged during transportation.
Batch Inconsistency
Significant differences in brightness and color temperature between different batches of LEDs.
Summary
Display manufacturers are most concerned with brightness, color consistency, reliability, and packaging size accuracy. Therefore, LED packaging manufacturers should focus on:
Optoelectronic performance control (BIN classification, color temperature control)
Reliability design (heat dissipation, packaging materials)
Packaging consistency (dimensions, tolerances, lenses)
Shipping management (packaging, batch tracking)