System for slicing silicon wafers
OwnerRobert A. Administrator of the National Aeronautics and Space Administration, with respect to an invention of Frosch, Earl R. Collinsinventors
Life of this patent
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Abstract
An improved system having at least one endless band saw blade characterized by a continuously regenerated cutting edge and unidirectionally driven along a pair of courses extended in mutual parallelism through a cutting station located near the midportion of said courses. The blade is supported at the cutting station by pairs of guides continuously rotated through less than 360.degree. of angular displacement during each cutting operation for thus continuously regenerating the blade-supporting surfaces of the guide whereby blade wobble substantially is eliminated.
Claims9
In a system including a cutting station for slicing a plurality of silicon wafers simultaneously from a plurality of boules during a single cutting operation, the improvement comprising:
- A. a ganged band saw including a plurality of endless band saw blades supported for simultaneous operation and arranged in side-by-side coplanar relation;
- B. means for imparting simultaneous unidirectional linear travel to each of said blades;
- C. means adjacently related to a cutting station for simultaneously feeding to said ganged band saw a plurality of boules of silicon arranged in spaced coplanar relation;
- D. means for reducing blade wobble including a plurality of guide means disposed in juxtaposition with the cutting station for receiving said blades in supported relation, each of said guide means being characterized by a pair of coaxially spaced disks supported in engaged relation with opposite side surfaces of one blade of said plurality;
- and
- E. means for angularly advancing said pair of disks in a direction opposing said unidirectional travel at a linear speed less than the rate of unidirectional travel of the blade.
In a system for slicing from a boule of silicon a plurality of silicon wafers in a single slicing operation, the improvement comprising:
- A. at least one endless band saw blade trained about a pair of mutually spaced drums and supported thereby for driven unidirectional travel along a pair of courses extended in mutual parallelism across a boule of silicon and characterized by a cutting surface for simultaneously forming in said boule a pair of saw kerfs;
- B. means for reconditioning the cutting surface of said blade including a knurling wheel disposed in engaged relation with the cutting surface for establishing serrations therealong, and means for reducing the thickness of the blade adjacent to the cutting surface comprising a pair of rollers characterized by a pair of cylindrical surfaces having defined therebetween a bite for receiving said blade in an engaged relationship;
- C. a pair of angularly displaceable guides for supporting said blade near the midportion of each of said courses, the guides of said pair being spaced apart a distance sufficient to receive therebetween said boule of silicon;
- and
- D. means for continuously advancing said guides in angular displacement for regenerating the surfaces of the guides disposed in engaged relation with the blades in juxtaposed relation with the cutting edge thereof.
A system for simultaneously slicing from a plurality of boules a plurality of silicon wafers of uniform thickness during a single cutting operation comprising:
- A. means for supporting a plurality of boules of silicon in side-by-side spaced parallelism;
- B. a plurality of endless band saw blades, each blade of said plurality being trained about a pair of mutually spaced drums and supported thereby for unidirectional travel from an upstream direction to a downstream direction relative to said boules along a pair of courses traversing the boules in spaced parallelism;
- C. each blade of said plurality of blades having defined along one edge surface thereof a cutting edge for forming simultaneously in said boules pairs of saw kerfs extended transversely through the boules in spaced parallelism with pairs of saw kerfs formed by other blades of said plurality;
- D. a plurality of angularly displaceable regenerative guides each being adapted to receive one blade of the plurality of blades, said guides being so arranged relative to the boules of the plurality as to position a first plurality of guides in an upstream relation with the boules and a second plurality of guides in a downstream relation with the boules;
- E. means for continuously driving the guides of said first plurality of guides in angular displacement in an upstream direction for continuously presenting to the cutting edge of each blade in upstream relation with each boule a surface previously unengaged by said blade;
- F. means for continuously depositing on the blades of said plurality a cutting slurry;
- and
- G. means for removing cutting slurry from the blades of said plurality.
Dependencies are inferred from the claim text.