Problem Background: A “False Pass” Detection Trap

A challenging issue arose on the production line for metal frames in smartphones: flatness measurements taken with conventional industrial lenses consistently showed “pass,” yet subsequent assembly frequently revealed uneven gaps and poor bonding. After investigation, the root cause was traced to measurement principle errors.

Root Causes of Measurement Errors: Perspective Distortion and Tilt Error

• Operating Condition: The metal frame is placed on the carrier, assuming a slight tilt of 0.5° (which is unavoidable in production).

• Measurement Principle: Conventional lenses exhibit perspective distortion, with light entering at varying angles.

• Critical Error: When the lens measures the height of the frame's side edges, it actually measures the projected length of the inclined edges rather than the true vertical height difference.

• Data Deviation: A 0.5° tilt can cause height measurement errors reaching tens of micrometers—sufficient to allow defective parts to “pass” as qualified products.

Solution: POMEAS CCD Vision Alignment System

Utilizing the LTCM1-110C-G achieves outstanding optical performance, including high resolution and low distortion. Combined with specialized illumination technology and CCD imaging, and integrated with control software, it enables visual imaging and precise positioning of products.