Unlike implied or inferred coplanarity, the true 3D optical inspection offered by the camera system from Adaptsys can precisely locate the surfaces of leads and solder balls in a 3D space. The system offers a selection of seating plane coplanarity measurements. The least mean squares (LMS) algorithm is used as the preferred method, where all leads or solder balls contribute to the calculation of the plane’s position. This is far more accurate than the simple 3-point seating plane used by many existing coplanarity inspection systems. The Adaptsys systems offer outstanding resolution of better than 10 microns, with features such as lead width measured to a resolution of just 3 microns.
Coplanarity problems can cause solder joints to fail during manufacture, or reduce system reliability in the field. The most common cause is due to handling of devices – particularly in a programming process – leads can become bent, and solder balls can be squashed, sliced or sheared. Device manufacturing can also cause coplanarity problems through burr on device leads or poorly formed solder balls in a BGA package. Adaptsys has found that in a typical manufacturing process around 1% of devices inspected will have unacceptable coplanarity that could cause failures. Some industries, most notably automotive, demand that manufacturers can inspect 100% of devices for coplanarity prior to pick and place.
Optimised for use with V-TEK taping machines, the optical coplanarity inspection ensures that all devices fall within the coplanarity tolerances before pick and place. In addition to coplanarity measurement, the system also offers inspection of lead pitch and slant, checking of marking and part orientation as well as inspecting the packaging for cracks and other faults, further increasing the quality of the production process.