R&D Operation Facilities
Keltech operates a complete research and development facility. The lapper and disc grinder were designed and built on-site. The vitrified diamond agglomerates were made and mold-formed into annular bands of islands on flexible discs here. Sapphire wafer abrading process procedures were developed, and test data organized to provide verification of both high cut rates and long disc abrade lives. This activity demonstrates the technology can be implemented anywhere in the world.
The heavy industrial prototype lapper machine is used to abrade sapphire wafers at high speeds. Flexible abrasive island discs are quickly attached with vacuum to a precision-flat air bearing spindle platen. Wafers are bonded to 6” discs that are also quickly attached to the wafer head with vacuum. Controlled pneumatic abrading pressure in the wafer head is applied during the lapping procedure. Water spray is applied to the rotating island discs to cool the wafers but avoid hydroplaning. 12” or 18” island discs can be used for abrading.
The disc grinder machine has a precision-flat air bearing platen spindle and a diamond grinding wheel on a translating carriage. It is used to grind-flat groups of workpiece’s top surfaces (or an island disc) into a common plane prior to abrasive polishing on the lapper machine. The disc grinder is a heavy industrial machine that holds an accuracy of 0.0001” over 10 inches of horizontal travel.
Keltech has an extensive machine shop used to build abrasive machine components and to modify and update existing machines. The shop has a Bridgeport mill and a Hardinge tool room lathe, both fully tooled with accessories. Grinders, belt sanders, vertical and horizontal saws and a wide range of hand tools are used for fabrication using a large inventory of solid and sheet metals plus polymers. There is also a wide variety of welders including TIG, MIG and gas plus a plasma torch cutter.
Electronics, Electronics Controls
Keltech has a large inventory of a wide range of measuring devices, readouts, electrical control devices, electrical components and motors. They are used for controlling and monitoring motors, temperature, pneumatic systems, fluid flow and positioning devices. These components are used for both abrading machines and process equipment.
Mechanical Components, Metals and Plastics
Thousands of different fasteners, mechanical and pneumatic components are stocked for development use. There is also a large inventory of mechanical screw drive slides, precision bearing slides and roller bearings. In addition, steel and aluminum angle, bars, rod, tubes and plates are stocked for machine and process development use. Both a wide variety of plastic materials and sheets are also used for abrasive disc backings and for process equipment.
Ovens and Furnace
There are a number of large Despatch industrial ovens that are used for curing of adhesives and for producing the vitrified agglomerate islands discs. A Paragon high temperature furnace is used to produce the vitrified diamond abrasive material that is fractured into abrasive agglomerates. Watlow PID temperature controllers are used for both the ovens and furnace.
Shop, Air Compressor, Vacuum Pump
Keltech has a sound insulated ventilated air compressor room with a 7.5 hp Ingersol Rand 2-stage air compressor that supplies large volumes of high-pressure air to the lapper and disc grinder air bearing platen spindles. An Ingersol Rand refrigerated air drier with filters is used for both the air bearing spindles and the lab air. Vacuum is provided by an automated Busch 2 hp vacuum pump with two 7.5 gallon surge tanks for the lapper, the disc grinder and the lab. A three-phase converter supplies power for the Bridgeport mill and the vacuum pump. Compressed air, water and vacuum is distributed to the lapper and disc grinder machines, the lab and the machine shop. A jib-crane hoist is used for assembly of the heavy lapper and disc grinder machines. Blower driven exhaust systems are used for the shop, the lab, the machine shop and both the lapper and disc grinder machines.
Keltech has a complete lab that is used for making vitrified diamond agglomerate materials and agglomerate island abrasive discs.
A wide range of diamond particle sizes, synthetic glass powders, many filler materials, solvents, adhesives and chemicals are selected from inventory for mixing of different vitrified agglomerate formulations and materials used to construct the island discs. Precision lab scales are used for weighing mix components under an exhaust ventilation hood.
The lab has an air bearing platen table that is used for precision measurements of abraded wafers and workpieces. Measurement instruments include many readout and gauge calipers and devices. Multiple precision-flat granite surface plates of different sizes are used for measurements. A group of 8” patterned hand-lap copper and cast iron plates are used for manual lapping of machine components using liquid abrasive slurries.
A Taylor-Hobson Surtronic surface roughness gauge and a large Lapmaster light band optical flatness measurement device are used for workpiece surface measurements. Multiple high-power microscopes along with magnifying optical devices are used to examine agglomerates and island discs.
The lab has dc power supplies and is outfitted with regulated high- and low-pressure air, vacuum and water lines.
Keltech has a complete office facility with desktop and laptop computers, color and standard printers, copiers and full array of office software. It has AutoCAD design, Ansys structural and heat transfer FEM and Fidap FEM fluid flow analytical programs.