A customizable, automated 3-D inspection system was developed by G2 Technologies in response to a client’s need for faster, more accurate connector inspection. Demand for connectors has grown in recent years with the increasing need for reliable, fail-safe electronics in a wide range of industries, including automotive, aerospace, and defense/military.
The new 3-D system combines a machine-vision based non-contact 3-D inspection system, a cleaning station, and electrical test and engraving stations. The system is built on a PXI platform from National Instruments and has the flexibility to inspect a variety of connectors with pin counts ranging from four to 32, and deliver one-cycle rolling changeovers between parts. It can achieve a 3.5 second takt time (the average customer demand time for a product) on each part.
The 3-D connector inspection system is installed after stitching, a process that accumulates contact pins and inserts them into molded connector housings. Stitched connectors enter on an input conveyor and pass under a Genie Nano M1920 GigE Vision camera from Teledyne DALSA.
An image of the connector acquired with illumination provided by a DL 194 diffuse dome light from Advanced Illumination is then analyzed to verify that the correct part is present and that it’s in the proper orientation to proceed through the inspection process. If the part is not correct or is improperly oriented, the system diverts it into a reject bin.
Parts deemed correct and properly aligned proceed to an orientation wheel that repositions the part board-side down for the next station, which is board-side inspection. A scanCONTROL 2650-25 laser line profiler from Micro Epsilon then scans the entire board side of the connector.
After board-side inspection, connector-side inspection takes place. Due to cycle time requirements, and the need to scan the part from both directions, inspection of the mating side of the connector is performed at two stations by two additional laser line profilers.
Two scans are used because of the shadowing effects created by the connector shell when the part is scanned from one side. To get a complete 3-D point cloud, the part is scanned from both directions, and the images are combined to mask out the shadows.
After visual inspection, the connector goes to a cleaning station, followed by electrical testing and finally, each connector goes through an engraving station. Passing connectors receive a date code and proceed to packaging. A failing connector receives a reject code that identifies the station in which it was rejected and is moved to a locked reject bin to ensure that it doesn’t get mixed with good parts.