Optical Triangulation Error Models under Dynamic Printed Circuit Board Warpage
Dynamic substrate distortion induces height shifts in optical triangulation systems, requiring real-time surface mesh interpolation to prevent false deposit rejects.
Telecentric Imaging
Perspective Correction
Optical lens configurations with parallel principal rays eliminate perspective error and magnification drift across varying object distances. In high-precision circuit board metrology, telecentric imaging maintains constant image scale regardless of component height or board displacement along the optical axis. Standard optical lenses create keystone distortion and parallax errors, causing tall components near the edge of the field of view to appear leaning outward.
Telecentric optics collect parallel light rays across the entire lens aperture, providing accurate dimensional measurements across stepped component surfaces.
Metrology Application
Accurate package dimensioning and solder joint inspection require uniform image scale across the camera field of view. Incorporating telecentric imaging into 3D optical inspection heads ensures that component width, lead pitch, and solder pad positioning measurements remain unaffected by vertical substrate movement. Dual-telecentric lenses maintain parallel ray geometry on both the object and image sides, maximizing edge contrast and minimizing distortion.
Inspection algorithms measure pin-to-pin pitch on high-density connectors without edge distortion artifacts skewing location coordinates. High-resolution telecentric optical assemblies enable accurate inspection of fine-pitch ball grid arrays and micro-lead frame packages across large circuit board panels.
Size Constraint
Telecentric lenses require front optical elements at least as large as the target field of view, increasing physical lens size and weight. Physical space constraints inside compact inspection machines limit the maximum field-of-view size obtainable with telecentric optical designs.