DFO Dual Faced Oscillating Grinding,
Lapping & Polishing Machines
The Lapmaster line of DFO Dual Faced Oscillating Machines incorporates a unique new concept for the precision finishing of large plano optics and electro-optics materials including LCD photomasks and sapphire windows. The machines are designed to process one work piece at a time, machining both sides simultaneously to extremely close tolerances. Depending upon the application, the machine can be fitted with fixed abrasive fine grinding plates, cast iron lapping plates, or aluminum plates for pad polishing.
The component is held in position between the plates in a work carrier that is rotating about its own axis and simultaneously driven in an eccentric motion, sweeping the component just off the edge of the machining plates. The specific path of the work piece can be controlled through synchronization of the oscillation drives. This configuration allows the entire surface of the plates to be covered by the component ensuring an even flat wear pattern, and consistent process results.
The DFO line of dual faced processing machines utilize five (5) degrees of motion to achieve flatness and parallelism tolerances beyond the capability of a standard 3 or 4 way planetary twin wheel machine. The top plate, bottom plate, work piece carrier, and two adjustable eccentrics are all independently driven, with variable speed control. Process down pressure requirements are pneumatically regulated and continuously controlled by a load cell and E to P pressure control.
The machines are operated through a color graphical interface to a programmable controller. The custom designed software allows the operator to develop sophisticated recipes. These recipes provide the operator control of the drive speeds, the path of the work piece as it oscillates across the plates, the pressure being exerted on the work piece, and slurry/coolant flow over a series of process steps; which can be recalled for later use.
The machine consists of a heavy-duty base, which houses both the Bottom polishing plate and the Top plate gantry assembly. The bottom machining plate is mounted on the base with a turntable bearing. This bearing design gives support under the centerline of the plate to balance the load and further limit deflection. The bearing is sized to handle axial loads many times greater than those expected during polishing for a long, trouble free life. The top machining plate is designed to lift up from the horizontal working position and pivot back to facilitate work piece loading and unloading.
Polishing compound is supplied through holes in the top and bottom polishing plates via a slurry feed system. A ceramic conditioning tool is included in order to dress the plates as required. Both the machining plates and the slurry system can be outfitted with temperature control for better process control if desired.
- Programmable process controller with user-friendly operator interface
- Pneumatic top plate pressure control with precise in-process monitoring by load cell
- Five, independently controlled machining plate and work piece drives
- Synchronization of work piece oscillation drives to control work piece path
- Heavy duty fabricated steel machine base
- Corrosion-resistant wetted parts and hardware
- Ceramic conditioning tool
- One blank work piece carrier
- Operating and maintenance manual
- Fixed abrasive fine grinding plates (2)
- Pad polishing plates (2)
- Cast iron lapping plates with cross-hatched groove pattern (2)
- Slurry/coolant delivery system (single pass or re-circulating)
- Coolant filtration system (for use with fine grinding configuration)
- Water cooled machining plates