Lapping apparatus and method for high speed lapping with a rotatable abrasive platen
First Claim
Patent Images
1. A process for lapping a surface comprising:
- a) providing a work piece to be lapped onto a workpiece support, said workpiece having a surface which is to be lapped,b) providing a rotating platen havingi) a back surface andii) front surface,c) providing an abrasive material on said front surface of said platen with the abrasive facing said surface of said workpiece which is to be lapped, andd) rotating said platen while said abrasive is in contact with said surface of said workpiece to be lapped, ande) supporting said workpiece on a workpiece support having a center of rotation and a support surface for said workpiece, said workpiece support comprising a spherical segment having a thickness along a radius passing through said center of rotation of the workpiece support which is less than the radius of a sphere defining the borders of the spherical segment, and said support surface has a surface area which is less than the surface area of the flat surface of a hemisphere cut from said sphere defining the borders of the spherical segment.
1 Assignment
0 Petitions
Accused Products
Abstract
Lapping or polishing at high speeds with fine abrasive particles offer significant advantages in the speed of lapping, savings of time in lapping, and smoothness in the finished articles. An improved lapping system comprises a lapper platen system comprising: a) a frame (e.g., having a total weight of at least 200 kg) supporting a work piece holder b) a rotatable platen having an abrasive surface comprising an abrasive sheet secured to said platen, said platen being capable of providing surface feet per minute speeds on in outer edge of at least about 1,500 surface feet per minute; and c) a work piece holder which is movable on said frame.
-
Citations
73 Claims
-
1. A process for lapping a surface comprising:
-
a) providing a work piece to be lapped onto a workpiece support, said workpiece having a surface which is to be lapped, b) providing a rotating platen having i) a back surface and ii) front surface, c) providing an abrasive material on said front surface of said platen with the abrasive facing said surface of said workpiece which is to be lapped, and d) rotating said platen while said abrasive is in contact with said surface of said workpiece to be lapped, and e) supporting said workpiece on a workpiece support having a center of rotation and a support surface for said workpiece, said workpiece support comprising a spherical segment having a thickness along a radius passing through said center of rotation of the workpiece support which is less than the radius of a sphere defining the borders of the spherical segment, and said support surface has a surface area which is less than the surface area of the flat surface of a hemisphere cut from said sphere defining the borders of the spherical segment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 70)
-
-
29. A process for lapping a surface of a workpiece comprising one of the following sequence of steps:
-
Sequence of steps A comprising; a) providing a work piece to be lapped, having at least one surface to be lapped, b) providing a rotating platen having i) a back surface and ii) a flat surface and providing a workpiece which can adjusted to a position parallel to said platen, said flat surface of said platen having openings therein through which air may flow, c) providing a sheet of abrasive material having an abrasive face and a back side, said back side being on said flat surface of said platen with the abrasive face of said sheet facing said at least one surface to be lapped, d) reducing gaseous pressure between said back side of said abrasive sheet and said flat surface of said platen to secure said sheet of abrasive material to said flat surface of said platen, e) rotating said platen at a rotational speed of at least 500 revolutions per minute and a surface speed at an outermost edge of said platen of at least 1500 surface feet per minute, and f) contacting said abrasive face and said at least one surface to be lapped on said work piece; Sequence of steps B 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 b) where b) is a rotating platen having i) a back surface and ii) a flat surface said flat surface of said platen having openings therein through which air may flow, c) providing a sheet of abrasive material having an abrasive face and a back side, said back side being on said flat surface of said platen with the abrasive face of said sheet facing said at least one surface to be lapped, d) wherein said sheet has an outer edge and an inner edge defining an annular distribution of abrasive, said inner edge having a diameter which is greater than one-third the diameter of said outer edge, e) rotating said platen at a rotational speed of at least 500 revolutions per minute, and f) contacting said abrasive face and said at least one surface to be lapped on said work piece; Sequence of steps C 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 the perimeter of said front side of said platen and is elevated with respect to a central area on said front side, thereby forming an annular region, 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 face to be lapped, d) securing said sheet of abrasive material to said flat surface of said plateau, and e) rotating said platen at at least 500 revolutions per minute and contacting said abrasive material and said work piece to remove material from said work piece; Sequence of steps D comprising a) providing a workpiece to be lapped, having at least one surface to be lapped, b) providing a rotating platen having i) a back surface and ii) a flat surface and providing a workpiece which can be adjusted to a position parallel to said platen by rotation about a pivot joint of a workpiece holder supporting said workpiece, said flat surface of said platen having openings therein through which air may flow, and said back surface having a pivoting joint with a shaft which rotates said platen, c) providing a sheet of abrasive material having an abrasive face and a back side, said back side being on said flat surface of said platen with the abrasive face of said sheet facing said at least one surface to be lapped, d) reducing gaseous pressure between said back side of said abrasive sheet and said flat surface of said platen to secure 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 wvorkpiece, and allowing said workpiece holder to pivot around said pivot joint so that said abrasive sheet and said at least one surface to be lapped become more parallel towards each other; Sequence of steps E comprising; a) providing a work piece with two surfaces to be lapped, b) providing two rotatable platens, each rotatable platen having i) a back surface and ii) a front surface, c) providing a sheet of abrasive material having an abrasive face and a back side, said back side being on said front surface of each of said two rotatable platens with the abrasive faces of each said sheet facing the other sheet, d) placing said work piece with two surfaces to be lapped between said two rotatable platens, so that each abrasive face faces only one of said two surfaces to be lapped, e) rotating said two platens at a rotational speed of at least 500 revolutions per minute, f) contacting each of said abrasive faces with said only one of said two surfaces to lapped, and g) lapping said two surfaces of said two work piece simultaneously; Sequence of steps F comprising; a) providing a work piece having two surfaces to be lapped, having at least one surface to be lapped, b) providing two rotatable platens, each rotatable platen having a back side and a front side, said front side facing a surface to be lapped on said work piece and each of said two platens having a flat plateau which is continuous around the perimeter of said front side of each of said platens and is elevated with respect to a central area on said front side, thereby forming an annular region, c) providing a sheet of abrasive material of said flat plateau on each of said two platens, said sheet of abrasive material having a front surface with an abrasive face and a back surface, with each said abrasive face facing only one of said two surfaces on said work piece to be lapped, d) securing said sheet of abrasive material to each said flat plateau, and e) rotating said platen at least 500 revolutions per minute and contacting said abrasive material on said two platens and said two surfaces to be lapped on said work piece simultaneously to remove material from said work piece; Sequence of steps G 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, b) providing a rotating platen having i) a back surface and ii) a front surface with a periphery, said front surface of said rotating platen having a raised edge symmetrically disposed about said periphery, c) providing a sheet of abrasive material having an abrasive face and a back side onto said raised edge to provide a symmetrical distribution of abrasive material on said rotating platen, said back side being on said front surface of said platen with the abrasive face of said sheet facing said at least one surface to be lapped, d) securing said sheet of abrasive material to said front surface of said rotating platen, and e) rotating said rotating platen at a rotational speed of at least 500 revolutions per minute, and f) contacting said abrasive face and said at least one surface to be lapped on said work piece; and Sequence of steps H 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, b) providing a rotating platen having i) a back surface, ii) a front surface, and a periphery, c) providing a sheet of abrasive material having an abrasive face and a back side onto said rotating platen, with the abrasive face of said sheet facing said at least one surface to be lapped, d) securing said sheet of abrasive material to said front surface of said rotating platen, e) rotating said rotating platen at a rotational speed of at least 500 revolutions per minute, and f) contacting said abrasive face and said at least one surface to be lapped on said work piece, g) providing a first amount of liquid to assist lapping to said abrasive surface physically in front of an area where work piece contacts said abrasive face, h) providing a second amount of liquid to assist in washing solid material from said abrasive surface physically after said area, and i) directing air against said abrasive surface physically after providing said first amount of liquid to assist in removing said first and second amounts of liquid from said abrasive surface.
-
-
30. An apparatus for lapping surfaces comprising:
-
a) a workpiece support, b) a rotatable platen having a back surface and a front surface, c) an abrasive material on said front surface of said platen with the abrasive facing said workpiece support, and d) a workpiece holder having a center of rotation and a support surface for a workpiece, said workpiece holder comprising a spherical segment having a thickness along a radius passing through said center of rotation of the workpiece holder which is less than, greater than or equal to the radius of a sphere defining the borders of the spherical segment, and said support surface has a surface area which is less than the surface area of the flat surface of a hemisphere cut from said sphere defining the borders of the spherical segment. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63)
-
-
64. An apparatus for lapping surfaces comprising:
-
a) a workpiece support, b) a rotatable platen having a back surface and a front surface, c) an abrasive material on said front surface of said platen with the abrasive material facing said workpiece support, and d) a workpiece holder having a center of rotation and a support surface for a workpiece, e) said workpiece holder comprising a segment having a single arc of movement within a support, and the single arc of movement rotating around said center of rotation, said workpiece holder having a thickness measured along a line extending along a radius of said single arc of movement passing through said center of rotation of the workpiece holder, which thickness is less than the radius of a circle defining borders of the segment, and said support surface has a surface area which is less than the surface area of the flat surface of a semicircle cut from said circle defining the borders of the segment. - View Dependent Claims (65, 66, 67, 68, 69)
-
-
71. A process for lapping a surface comprising:
-
a) providing a work piece to be lapped onto a workpiece support, said workpiece having a surface which is to be lapped, b) providing a rotating platen having i) a back surface and ii) front surface, c) providing an abrasive material on said front surface of said platen with the abrasive facing said surface of said workpiece which is to be lapped, and d) rotating said platen while said abrasive is in contact with said surface of said workpiece to be lapped, and e) supporting said workpiece on a workpiece support having a center of rotation and a support surface for said workpiece, said workpiece support comprising a spherical segment having a thickness along a radius passing through said center of rotation of the workpiece support which is greater than the radius of a sphere defining the borders of the spherical segment, and said support surface has a surface area which is less than the surface area of the flat surface of a hemisphere cut from said sphere defining the borders of the spherical segment. - View Dependent Claims (72, 73)
-
Specification