High resolution piggyback linear motor design for placement systems and the like

A high precision placement system comprising:

• a platen having a planar working surface, and first and second sets of parallel uniformly spaced grid-like groove lines formed in the platen surface for defining an orthogonal matrix of teeth;
• first and second two-dimensional linear motor means each having first and second forcer means and means for operating said first and second forcer means to move said first and second two-dimensional linear motor means over the planar working surface of said platen;
• third and fourth two-dimensional positioning means each respectively mounted upon said first and second two-dimensional linear motor means;
• and
• means for moving said first, second, third and fourth two-dimensional positioning means for precision positioning thereof, the resolution of said third and fourth positioning means being greater than the resolution of said first and second positioning means.

A precision placement system comprising:

• first mounting means;
• reference means;
• first positioning means for moving said first mounting means relative to said reference means in mutually perpendicular directions along substantially common plane;
• second mounting means;
• second positioning means mounted upon said first mounting means for moving said second mounting means in mutually perpendicular directions substantially along a second common plane, said second positioning means having a higher resolution than said first positioning means;
• said second positioning means further comprising means for rotating said second mounting means about a predetermined axis.

A precision placement system comprising:

• first mounting means;
• reference means;
• first positioning means for moving said first mounting means relative to said reference means in mutually perpendicular directions along substantially common plane;
• second mounting means;
• second positioning means mounted upon said first mounting means for moving said second mounting means in mutually perpendicular directions substantially along a second common plane, said second positioning means having a higher resolution than said first positioning means;
• said second positioning means further comprising means for rotating said second mounting means about a predetermined axis;
• holding means on said second mounting means for holding a component for delivery of said component to a working surface adjacent to said holding means;
• and
• camera means mounted upon said second mounting means for mapping the position of said component relative to said working surface, including means for generating signals for operating said second positioning means in the event of misalignment between said components and said working surface.

A method for precision positioning of an object releasably mounted upon an output platform movable by means of a first positioning system which in turn is mounted upon the intermediate output platform of a second positioning system which is arranged to move relative to a work surface located beneath said object, and holding means mounted on said platform for holding a component, comprising the steps of:

• operating the second positioning system to move the first positioning system in mutually perpendicular directions to drive the first positioning system to a predetermined location;
• determining if there is any misalignment between the component held by the holding means and the work surface;
• and
• operating the first positioning system responsive to detection of a misalignment of said components relative to the desired position on the working surface.