CPk using glass slugs?

Read an earlier thread about using glass slugs to determine placement CPk. Can it actually be done this way? What's the procedure? Be interesting to know 'cause if it's feasible, I'd probably get myself a kit. None of us here are stat's experts and wouldn't mind some input.

Joe

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| Read an earlier thread about using glass slugs to determine placement CPk. Can it actually be done this way? What's the procedure? Be interesting to know 'cause if it's feasible, I'd probably get myself a kit. None of us here are stat's experts and wouldn't mind some input. | | Joe | Works great. Buy a kit, setup program, and populate component slugs on PCB glass plate. Slugs held to glass by double back tape. Verify slugs placement via an optical comparator or make custom plate with tollerance perimeter you would like. I run this test on a regular basis to verify machine calibration and correct operation. Also use this test to qualify pick and place equipment. Just keep in mind that glass plate test using doubleback tape is the best media for placement. Using real PCB and components you will have factors such as: how well is component supported by nozzle, PCB warpage, HASL solder variation, component coplanarity issues, component movement in solder paste when placed, board support. All these things can throw off your placement accuracy and repeatability.

Chris

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