Air Bearing Module Alignment
Original Publication Date: 1987-Oct-01
Included in the Prior Art Database: 2005-Feb-02
Printed circuit cards are now using surface mount modules of increasing physical size and pin count, and decreasing pin pitch. The fineness of pitch and the resulting fragility of the pins is leading to the increasing use of vision techniques for inspection of the pins before assembly and for the determination of exact module position to allow accurate placement on the board. However, to get maximum resolution in any vision system used, it is necessary to fill the camera field of view as fully as possible. Due to the fragility of the module pins, the packaging methods usable for these modules are limited, and so they are supplied in thin plastic vacuum-formed waffle sheets, often containing 60 modules per sheet.