Lapping apparatus and lapping method using abrasive sheets

A process for lapping a surface comprising:

• a) providing a work piece to be lapped, having at least one surface to be lapped,
• b) providing a rotating platen having a back side and a front side, said front side facing said work piece and having a flat plateau which is continuous around a perimeter of said front side of said platen and is elevated with respect to a central area on said front side,
• c) providing a sheet of abrasive material on said flat plateau, said sheet of abrasive material having a front surface with an abrasive face and a back surface, with said abrasive face facing said at least one surface to be lapped,
• d) securing said sheet of abrasive material to said flat surface of said plateau, and
• e) rotating said platen at least 500 revolutions per minute and contacting said abrasive material and said work piece to remove material from said work piece.

A lapper platen system comprising:

• a) a shaft which is connected to a rotatable platen having vents for air on a front surface of said platen, said platen having a back side to which said shaft is connected and a flat front side on said platen to which can be secured an abrasive sheet by reduced air pressure conveyed through said vents;
• b) a frame having a total weight of at least 200 kg supporting a work piece holder and said shaft connected to a rotatable platen;
• c) a work piece holder which is movable on said frame;
• c) said work piece holder is attached to a movable element on said frame which is capable of moving along said frame in a direction towards and away from said platen to perform lapping of a work piece held on said work piece holder;
• d) said work piece holder having screw control element thereon which allow for independent movement and alignment of said work piece holder along three perpendicular axes so that a work piece on said work piece holder can be adjusted and oriented towards parallelity with said platen so that a work piece can be lapped;
• and
• e) said screw control elements having at least 50 settings per rotation, each setting moving said shaft along one of said three axes by a dimension less than 0.05 mm.

A process for lapping a surface comprising:

• a) providing a work piece to be lapped, said work piece having a first surface and a second surface which are parallel to each other, and at least one of said first and second surface is a surface to be lapped,
• b) providing a first and second rotating platen, each of said first and second rotating platen having i) a back surface and ii) a flat front surface which can be adjusted so that said first platen is facing and parallel to said first surface of said work piece and said second platen is facing and parallel to said second surface of said work piece,
• c) providing a sheet of abrasive material on at least said flat surface of said first platen with an abrasive face of said sheet facing said first surface of said work piece which is said at least one surface to be lapped,
• d) securing said sheet of abrasive material to said flat surface of said first platen, and
• (1) putting a liquid between both i) said first platen and said first surface of said work piece and ii) said second platen and said second surface of said work piece,
• (2) rotating both of said platen at least 500 revolutions per minute and contacting said abrasive material and said work piece,
• (3) wherein water pressure between said both i) said first platen and said first surface of said work piece and ii) said second platen and said second surface of said work piece are sufficiently similar that said work piece does not flex more than 0.1 mm at its exterior regions between said two platens.

A lapper platen system comprising:

• a) a shaft which is connected to a rotatable platen, said platen having a back side to which said shaft is connected and a flat front side on said platen to which can be secured an abrasive sheet;
• b) a frame having a total weight of at least 200 kg supporting a work piece holder and said shaft connected to a rotatable platen;
• c) said rotatable platen is attached to a movable element which is capable of moving along said frame in a direction towards and away from said work piece to be lapped,
• d) said work piece holder having control element thereon which allow for independent movement and alignment of said work piece holder along three perpendicular axes so that said flat face of said platen can move towards parallelity with said platen so that a work piece can be lapped;
• and
• e) said control elements having at least 50 settings per rotation, each setting moving said shaft along one of said three axes by a dimension less than 0.05 mm.