Drilling apparatus with a decoupled force frame and metrology frame for enhanced positioning

A PCB substrate drilling apparatus comprising:

• a supporting base;
• an x axis linear drive unit residing on said supporting base and having an x axis stationary drive track and an x axis traveling arm;
• a y axis linear drive unit residing on said supporting base and having a y axis stationary drive track and a y axis traveling arm;
• a positionable x axis moving table assembly coupled to said x axis traveling arm;
• a positionable y axis moving carriage coupled to said y axis traveling arm;
• a z axis balanced reactionary force drill unit coupled to said y axis moving carriage, wherein said z axis reactionary force drill unit comprises a drill unit base plate connected to said moving carriage,
• a z axis moveable drill spindle rotationally housed in a first guide bushing assembly that is mounted in a lower guide sleeve affixed to said drill unit base plate;
• a z axis spindle drive unit comprised of a voice coil and a voice coil magnet coupled to a reaction mass wherein said voice coil is partially housed within a recess in said voice coil magnet, and wherein said z axis spindle drive unit is moveably housed in a second guide bushing assembly that is mounted in an upper guide sleeve affixed to said drill unit base plate,
• wherein said voice coil and said voice magnet coupled to said reaction mass are each simultaneously moveable in opposite directions along the z axis;
• wherein a mass of said voice coil, said spindle and a flexure is less than a mass of said voice coil magnet coupled to said reaction mass;
• and
• said flexure connector affixed between said spindle and said z axis spindle drive unit;
• wherein said z axis drill unit has a series of sequentially joined connection members forming a pivotable phase linkage, wherein a first connection member is pivotally affixed to said voice coil magnet and a last connection member is affixed to said voice coil, and wherein said first connection member also is affixed to the bottom of said upper guide sleeve by a pivot support that extends from said upper guide sleeve and is aligned along a linear axis of the spindle, wherein said first connection member passes horizontally through said pivot and the ratio of the distance from said pivot to a distal end of said first connection member compared to the distance from said pivot to a proximate end of said first connection member approximates the ratio of a combined mass of the magnet and the reaction mass to a combined mass of the voice coil, the flexure and the spindle.