It is often necessary to grind (polish) off layers of a semiconductor so that the inner structures can be made available for visual inspection, often by observation using an electron microscope. A polishing fixture useful for holding the semiconductor (or other device to be polished) against a polishing wheel for this purpose is the subject of U.S. Pat. No. 5,272,844. Some polishing operations are now performed using a positioning structure that is suspended over a grinding wheel. The positioning structure is a frame with an open center and a plurality of circumferentially spaced openings into which a die holding tool can be placed. The operator uses the side of the opening to help stabilize the holding tool while the die is being polished. Problems exist with the positioning device when it is desired to polish dies without requiring the operator to keep his/her hands on the tool. These problems primarily concern the fact that the tool is not held securely and thus “wobbles”. Stops are provided on the device for maintaining the tool within the openings. However, the stops are ineffective for their intended purpose.
Polishing in this manner is a manual process which can take anywhere from half a day to two or three days with an operator standing in front of the grinding wheel and holding the device while the wheel spins. The holding device is constructed such that it allows for the semiconductor to be positioned in various orientations depending upon the planar angle desired to be grinded away. This procedure is slow and tedious and often results in cramped hands and fingers.