Since 1989 Accretech has been designing, developing and manufacturing equipment for the semiconductor industry. Today they are a subsidiary of Tokyo Seimitsu. At HST we’re very familiar with their many dicing saw air bearing spindles.
When this Accretech TSW spindle came into us the customer’s main concern was “a strange, high-pitched noise when it’s running.” The spindle was still operational. Initially we could not duplicate the concern. However, after running the spindle on our test bench for several hours it began to make an intermittent high pitched oscillation.
Upon disassembly we found the main reason for failure!
Outer Axial Bearing
Accretech TSW Shaft
At some point the rotating shafts thrust surface made contact with the Outer Axial bearing and slightly damaged it. This damage caused a very small imbalance in air flow through the spindle. The imbalance was so slight that it only caused an intermittent high pitched oscillation or “honking” noise. We repaired the axial bearing thrust surface in our machine shop and this eliminated this problem.
Note evidence of moisture contamination
Contributing to the failure was the fact that moisture, likely a surfactant of some type, migrated into the spindles axial area. This resulted in a loss of axial lift and possibly the subsequent damage to the outer axial bearing.
<1 micron runout at wheel mount face & OD
After repairing the outer axial bearing and removal of all rust and scaling we reassembled the spindle and began our rigorous testing. The rotating mass did take some time to balance but after doing so the spindle ran excellent! Also the runout on the customers wheel mount measured less than 1 micron! When a diamond blade is rotating at 30,000 to 60,000 RPM and making cuts on a delicate silicon wafer, this is very important!
Accretech spindle repaired and ready to ship
After our testing proved the spindle ran like new, we prepped and packaged it for return to the customer. We assume the truck driver will take the bumpiest roads with the most potholes. So we take great care with our packaging! The coolant lines are cleared of moisture and plugged, we wrap the spindle tightly in Cortec VpCI plastic designed to prevent corrosion and we throw in several desiccants to be safe. The spindle is then surrounded by soft but sturdy foam on all sides and the double corrugated box is stapled and strapped shut. It is now ready for the return ride home!
For expert Accretech spindle repair, please email or call us at 603-483-0333 for a free, no obligation quote. We offer one-year warranty and Quick-Turn-Around. We are fast, experienced and our work is guaranteed!!