Simultaneous double-side grinding of semiconductor wafers
First Claim
1. A method for the correction of grinding spindle orientation in a double-side grinding machine for the simultaneous double-side machining of semiconductor wafers, the grinding machine having two coaxial grinding spindles, each spindle comprising a grinding disk flange for attaching a grinding disk, the method comprising:
- torsionally coupling the two grinding spindles by a torsional coupling element;
providing a measuring unit comprising an inclinometer and at least two sensors for distance measurement;
mounting the measurement unit between the grinding disk flanges, the grinding disk flanges having no grinding disks attached thereon, such that the grinding spindles are in the same position they would occupy during a later double-side machining of a semiconductor wafer;
rotating the torsionally coupled grinding spindles and determining radial and axial correction values for an axial alignment of the two grinding spindles by means of the inclinometer and the sensors, and using these values to correct an orientation of the two grinding spindles to obtain a symmetrical orientation of the two grinding spindles.
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Accused Products
Abstract
Correction of grinding spindle positions in double-side grinding machines for the simultaneous double-side machining of semiconductor wafers is achieved by torsionally coupling the two grinding spindles, each comprising a grinding disk flange for receiving a grinding disk, and providing a measuring unit with an inclinometer and two sensors for distance measurement, between the two grinding disk flanges such that the grinding spindles are essentially in the position they would have with mounted grinding disks during the grinding process, wherein the coupled grinding spindles are rotated while inclinometer and sensors determine radial and axial correction values of axial alignment to adjust the grinding spindles to a symmetrical orientation. The spindle positions may be corrected under the action of process forces.
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Citations
13 Claims
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1. A method for the correction of grinding spindle orientation in a double-side grinding machine for the simultaneous double-side machining of semiconductor wafers, the grinding machine having two coaxial grinding spindles, each spindle comprising a grinding disk flange for attaching a grinding disk, the method comprising:
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torsionally coupling the two grinding spindles by a torsional coupling element; providing a measuring unit comprising an inclinometer and at least two sensors for distance measurement; mounting the measurement unit between the grinding disk flanges, the grinding disk flanges having no grinding disks attached thereon, such that the grinding spindles are in the same position they would occupy during a later double-side machining of a semiconductor wafer; rotating the torsionally coupled grinding spindles and determining radial and axial correction values for an axial alignment of the two grinding spindles by means of the inclinometer and the sensors, and using these values to correct an orientation of the two grinding spindles to obtain a symmetrical orientation of the two grinding spindles. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification