Lapping apparatus and process with raised edge on platen

A process for lapping a surface comprising:

• a) providing a work piece to be lapped, having at least one surface to be lapped which can be adjusted to a position parallel to said at least one surface of a rotating platen with abrasive thereon, said work piece being supported by a work piece holder on a pivot joint,
• b) providing a rotating platen having i) a back surface, ii) a front surface, and iii) a raised edge forming an abrading plateau on said front surface of said rotating platen, said abrading plateau having a sheet of abrasive material having an abrasive face and a back side, and said back surface pivotally connected to a rotating joint which is in turn connected to a shaft which rotates said platen,
• c) said abrasive face of said sheet facing said at least one surface to be lapped,
• d) securing said sheet of abrasive material to said flat surface of said platen, and
• e) rotating said platen at a rotational speed of at least 500 revolutions per minute by rotating said shaft, and
• f) contacting said abrasive face and said at least one surface to be lapped on said work piece, and allowing said work piece to pivot around said pivot joint so that said abrading plateau and said at least one surface to be lapped become more parallel towards each other.

A lapper platen system comprising:

• a) a rotatable platen having i) a back surface and ii) a front surface, wherein said front surface of said rotating platen facing a work piece and said front surface has 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 surface and is defined by an area bounded by two concentric circles having different diameters,
• b) said front surface also having vents for air,
• c) said platen having a back side to which a shaft is connected and a front side on said platen to which is secured an abrasive sheet by reduced air pressure conveyed through said vents,
• d) said back side also being connected to said shaft which rotates said platen;
• e) a frame having a total weight of at least 200 kg supporting a work piece holder and said shaft connected to a rotatable platen,
• f) a work piece holder which is movable on said frame;
• g) 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,
• h) 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 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
• i) said control elements having at least 1,000 settings per rotation, each setting moving said shaft along one of said three axes by a dimension less than 0.001 mm.

A lapper system comprising:

• a) a shaft which is connected to a rotatable platen having on a front surface of said platen vents for air, said rotatable platen having a back side to which said shaft is connected and a flat front side on said rotatable 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;
• d) 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;
• e) 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 a work piece on said work piece holder can be adjusted and oriented towards parallelity with said rotatable platen so that a work piece can be lapped;
• and
• f) said control elements having at least 1000 settings per rotation, each setting moving said shaft along one of said three axes by a dimension less than 0.005 mm;
• wherein said lapper system includes a pivoting lapper platen system comprising:
• g) a shaft which is connected to said rotatable platen, said rotatable platen having a back side to which said shaft is connected and a front side on said rotatable platen to which can be secured an abrasive sheet, said rotatable platen having i) a back surface, ii) a front surface, and iii) a raised edge forming an abrading plateau on said front surface of said rotatable platen, with an abrasive sheet secured to said raised edge.