Standard SMT Placement Rate Verification against Real PCB Assembly Throughput
Real PCB assembly throughput averages forty to sixty percent of IPC-9850 placement rates due to board transfer, vision checks, and component variation.
Flight Vision
Inspection System
Image capture and processing occur while the placement head is moving from the component feeder to the printed circuit board. Utilizing flight vision eliminates the need for the head to stop over a stationary camera, which increases the throughput of the assembly line. The camera is typically mounted directly on the moving gantry or head assembly to view the component held by the nozzle from below.
Image Acquisition
Strobe lighting freezes the motion of the component as it passes over the sensor or as the head carries it through the air. Sophisticated algorithms then calculate the center of the part and the angle of its leads relative to the nozzle. Because flight vision processes the data in real-time, the machine can apply offset corrections to the X, Y, and theta coordinates before the nozzle reaches the target site.
This method works best for small to medium components where the field of view and resolution requirements are manageable.
Capability Limit
Large quad flat packs or fine-pitch ball grid arrays often exceed the processing speed or resolution limits of this on-the-fly approach. These complex parts usually require a high-resolution stationary camera for detailed lead inspection. Heavy components or those with reflective surfaces might also suffer from motion blur or lighting artifacts during high-speed transit.
Switching between flight vision and stationary inspection allows the machine to balance speed for passives with accuracy for integrated circuits.