Abrasive coated disk islands using magnetic font sheet

Abstract

Abrasive disk sheet articles having raised islands coated with abrasive have a flexible disk polymer backing. The top flat surfaces of the raised islands are coated with a liquid controlled-thickness slurry mixture of abrasive particles and a polymeric adhesive by use of a magnetic precision-thickness coating-control font sheet having individual open holes that are slightly smaller than the respective raised islands. The magnetic coater font sheet is placed in flat-surfaced contact with the raised island surfaces where each individual font sheet open hole is aligned with a respective island surface. A magnet placed on the non-island surface of the disk polymer backing urges the magnetic coater font sheet into conformal contact with the island surfaces. A squeegee device moved along the font sheet fills and level coats the island tops with a uniform-thickness abrasive slurry mixture. After coating, the font sheet is removed and the abrasive slurry is solidified.

Claims

1. An abrasive raised island disk article comprising: a) a circular, flexible, non-magnetic backing disk substrate having a backing disk substrate material, a backing disk substrate thickness, a backing disk substrate outer diameter, a backing disk substrate first surface, and a backing disk substrate second surface; b) a nominally-annular pattern of individual raised island structures integral to or attached to the backing disk substrate first surface wherein the nominally-annular pattern of raised island structures has an approximate outer diameter and an approximate inner diameter and the individual raised island structures have a raised island structure nominally flat surfaced top surface, a raised island structure nominally flat surfaced top shape, a raised island structure nominally flat surfaced top shape centroid, and a raised island structure height; c) a flexible magnetic material abrasive slurry coating font sheet comprising a magnetic coating font sheet first surface, a magnetic coating font sheet second surface, a magnetic coating font sheet uniform thickness, and a magnetic coating font sheet nominally-annular pattern of individual open holes wherein the individual open holes extend through the thickness of the magnetic coating font sheet and wherein the individual open holes have a magnetic coating font sheet open hole shape, a magnetic coating font sheet second surface open hole shape, and a magnetic coating font sheet second surface open hole shape centroid; d) wherein the pattern of the magnetic coating font sheet individual open holes is approximately the same as the pattern of raised island structures whereby placement of the magnetic coating font sheet second surface in flat-surfaced contact with the raised island structures nominally flat surfaced tops allows individual magnetic coating font sheet open holes to be aligned with respective raised island structures nominally flat surfaced tops where the magnetic coating font sheet second surface open hole shape centroids are in near-coincident alignment with the respective individual raised island structure nominally flat surfaced top shapes centroids and where the magnetic coating font sheet individual open holes are nominally-smaller than the respective raised island structures nominally flat surfaced tops; e) wherein a magnet placed in contact with the backing disk substrate second surface or positioned a selected distance from the backing disk substrate second surface provides a magnetic force that acts upon the magnetic abrasive slurry magnetic coating font sheet thereby urging the magnetic coating font sheet second surface to be in conformal flat-surfaced contact with the raised island structures nominally flat surfaced tops wherein the magnetic font sheet is structurally supported by the raised island structure nominally flat surfaced tops; f) a thickenable liquid slurry mixture of an adhesive and abrasive particles filling the magnetic coating font sheet individual open holes wherein the liquid slurry mixture of an adhesive and abrasive particles contacts and attaches to individual raised island structure nominally flat surfaced top surfaces; g) wherein the liquid slurry mixture filled magnetic coating font sheet open holes are level-filled with the magnetic coating font sheet first surface; h) the liquid slurry mixture of adhesive and abrasive particles contained in the liquid slurry mixture filled individual open holes wherein the magnetic coating font sheet is separated from the nominally-annular pattern of raised island structures nominally flat surfaced top surfaces leaving the individual raised island structures nominally flat surfaced top surfaces coated with a uniform thickness of the liquid slurry mixture of adhesive and abrasive particles; and i) the thickenable mixtures of adhesive and abrasive particles contained in the magnetic coating font sheet open holes, when thickened and attached to the individual raised island structure's individual raised island nominally flat surfaced top surface have a thickenable mixture of adhesive and abrasive particles first surface adhesively attached to the individual raised island structures nominally flat surfaced tops and have partially or completely solidified or non-solidified thickenable mixtures of adhesive and abrasive particles exposed second surfaces that opposes the thickenable mixture of adhesive and abrasive particles first surface.

2. The article of claim 1 wherein the magnet comprises a permanent magnet or an electromagnet.

3. The article of claim 1 wherein the flexible non-magnetic backing disk substrate backing disk substrate material comprises flexible materials selected from the group consisting of a polymer, aluminum, brass, non-magnetic stainless steel, cloth, woven fiber material and combinations thereof.

4. The article of claim 1 wherein the abrasive particles comprises particles selected from the group consisting of diamond, cubic boron nitride, aluminum oxide and combinations thereof.

5. The article of claim 1 wherein the liquid slurry mixture adhesive comprises adhesives selected from the group consisting of phenol formaldehydes, epoxies, polyurethanes and combinations thereof.

6. The article of claim 1 wherein the liquid slurry mixture adhesive contains solvents comprising solvents selected from the group consisting of water, alcohols, methyl ethyl ketone, toluene and combinations thereof.

7. The article of claim 1 wherein the liquid slurry mixture contains at least one filler agent selected from the group consisting of organic particles, inorganic particles, polymer agglomerates, glass beads, hollow glass beads, fumed silica and combinations thereof.

8. The article of claim 1 wherein a release agent coating is applied to the magnetic coating font sheet wherein the release agent comprises release agents selected from the group consisting of silicone oil, silicon grease, polytetrafluoroethylene coatings, petroleum jelly, paraffin, mold release agents and combinations thereof.

9. The article of claim 1 wherein the individual raised island structure nominally flat surfaced top shapes comprises island shapes selected from the group consisting of: circular, elliptical, rhombus, pie and rectangular shapes.

10. The article of claim 1 wherein a flat plate is placed in flat-surfaced conformal contact with the exposed second surfaces of the partially or non-solidified liquid slurry mixture of adhesive and abrasive particles coated on the raised island structures after the magnetic coating font sheet is separated from the raised island structures nominally flat surfaced tops wherein contact of the exposed second surfaces of the liquid slurry mixture of partially or non-solidified liquid slurry mixture adhesive and liquid slurry mixture coatings with the flat plate positions the exposed second surfaces of the liquid slurry mixture of partially or non-solidified liquid slurry mixture adhesive and liquid slurry mixture coatings into a common plane.

11. The article of claim 10 wherein the flat plate that contacts the second surfaces of the adhesive and liquid slurry mixture coatings is positioned parallel to the backing disk substrate second surface wherein the second surfaces of the liquid slurry mixture of adhesive and liquid slurry mixture coatings on the individual raised island structures are parallel to the backing disk substrate second surface to provide an abrasive raised island disk article having a uniform thickness measured from the second surface of the adhesive and abrasive particles coated on the raised island structures to the backing disk substrate second surface.

12. The article of claim 1 wherein the second surfaces of the solidified mixtures of adhesive and abrasive particles that are adhesively attached to the individual raised island structures nominally flat surfaced top surfaces are ground flat to provide an abrasive raised island disk article having a uniform thickness measured from the second surfaces of the adhesive and abrasive particles on the coated raised island structures nominally flat surfaced top surfaces to the backing disk substrate second surface.

13. The article of claim 1 wherein the raised island structures nominally flat surfaced top surfaces are ground flat prior to coating the raised island structures nominally flat surfaced top surfaces with the liquid slurry mixture of an adhesive and abrasive particles.

14. A process for coating a pattern of nominally flat surfaced raised island structures attached to a flexible backing sheet disk substrate with a liquid slurry mixture of an adhesive and abrasive particles comprising: a) providing a circular, flexible, non-magnetic backing disk substrate having a backing disk substrate material, a backing disk substrate thickness, a backing disk substrate outer diameter, a backing disk substrate first surface, and a backing disk substrate second surface; b) providing a nominally-annular pattern of individual raised island structures integral to or attached to the backing disk substrate first surface wherein the nominally-annular pattern of raised island structures has an approximate outer diameter and an approximate inner diameter and the individual raised island structures have a raised island structure nominally flat surfaced top, a raised island structure nominally flat surfaced top shape, a raised island structure nominally flat surfaced top shape centroid, and a raised island structure height; c) providing a flexible magnetic material abrasive slurry magnetic coating font sheet comprising a magnetic coating font sheet first surface, a magnetic coating font sheet second surface, a magnetic coating font sheet uniform thickness, and a magnetic coating font sheet nominally-annular pattern of individual open holes wherein the individual open holes extend through the thickness of the magnetic coating font sheet and wherein the individual open holes have a magnetic coating font sheet open hole shape and a magnetic coating font sheet second surface open hole shape centroid; d) placing the magnetic coating font sheet second surface in flat-surfaced contact with the raised island structures nominally flat surfaced tops and aligning the individual magnetic coating font sheet open holes with respective raised island structures nominally flat surfaced tops where the magnetic coating font sheet second surface open hole shape centroids are in near-coincident alignment with the respective individual raised island structure nominally flat surfaced top shapes centroids and where the magnetic coating font sheet individual open holes are nominally-smaller than the respective raised island structures nominally flat surfaced tops; e) placing a magnet in contact with the backing disk substrate second surface or positioned a selected distance from the backing disk substrate second surface provides a magnetic force that acts upon the magnetic abrasive slurry magnetic coating font sheet thereby urging the magnetic coating font sheet second surface to be in conformal flat-surfaced contact with the raised island structures nominally flat surfaced tops wherein the magnetic font sheet is structurally supported by the raised island structure nominally flat surfaced tops; f) providing a thickenable liquid slurry mixture of an adhesive and abrasive particles filling the magnetic coating font sheet individual open holes wherein the liquid slurry mixture of an adhesive and abrasive particles contacts and attaches to individual raised island structures nominally flat surfaced top surfaces; g) providing a squeegee or flexible doctor blade device wherein the squeegee or doctor blade device that is positioned in contact with the magnetic coating font sheet first surface and is moved across the liquid slurry mixture filled individual open holes while in conformal contact with the magnetic coating font sheet first surface wherein excess liquid slurry mixture is removed by the squeegee or doctor blade device from the magnetic coating font sheet open holes and wherein the abrasive slurry mixture filled magnetic coating font sheet open holes are level-filled with the magnetic coating font sheet first surface; h) thickening the liquid slurry mixture of adhesive and abrasive particles contained in the individual liquid slurry mixture filled open holes wherein the magnetic coating font sheet is separated from the nominally-annular pattern of raised island structures nominally flat surfaced tops leaving the individual raised island structures nominally flat surfaced top surfaces coated with a uniform thickness of the liquid slurry mixture of adhesive and abrasive particles; i) wherein the thickened mixture of an adhesive and abrasive particles first surfaces are adhesively attached to the individual raised island nominally flat surfaced top surfaces and have partially or completely solidified or non-solidified thickened mixtures of adhesive and abrasive particles exposed second surfaces that opposes the thickened mixture of adhesive and abrasive particles first surface.

15. A process according to claim 14 wherein the magnet is at least one permanent magnet or at least one electromagnet.

16. A process according to claim 14 wherein the flexible non-magnetic backing disk substrate material comprises flexible materials selected from the group consisting of a polymer, aluminum, brass, non-magnetic stainless steel, cloth and woven inorganic fiber material.

17. A process according to claim 14 wherein the abrasive particles comprises particles selected from the group consisting of diamond, cubic boron nitride and aluminum oxide.

18. A process according to claim 14 wherein the liquid slurry mixture adhesive comprises adhesives selected from the group consisting of phenol formaldehydes, epoxies and polyurethanes.

19. A process according to claim 14 wherein the liquid slurry mixture adhesive contains solvents comprising solvents selected from the group consisting of water, alcohols, methyl ethyl ketone, toluene and combinations thereof.

20. A process according to claim 14 wherein a release agent coating is applied to the magnetic coating font sheet wherein the release agent comprises release agents selected from the group consisting of silicone oil, silicon grease, polytetrafluoroethylene coatings, petroleum jelly, paraffin and mold release agents.

21. A process according to claim 14 wherein a flat plate is placed in flat-surfaced conformal contact with the exposed second surfaces of the partially or non-solidified liquid slurry mixture of adhesive and abrasive particles coated on the raised island structures after the magnetic coating font sheet is separated from the raised island structures nominally flat surfaced tops wherein contact of the exposed second surfaces of the liquid slurry mixture of partially or non-solidified liquid slurry mixture adhesive and liquid slurry mixture coatings on the individual raised island structures with the flat plate positions the exposed second surfaces of the liquid slurry mixture of partially or non-solidified liquid slurry mixture adhesive and liquid slurry mixture coatings into a common plane.

22. A process according to claim 21 wherein the flat plate that contacts the second surfaces of the adhesive and liquid slurry mixture coatings is positioned parallel to the backing disk substrate second surface wherein the second surfaces of the liquid slurry mixture of adhesive and liquid slurry mixture coatings on the individual raised island structures are parallel to the backing disk substrate second surface to provide an abrasive raised island disk article having a uniform thickness measured from the second surface of the adhesive and abrasive particles coated raised island structures to the backing disk substrate second surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an isometric view of an abrasive disk with an annual band of raised islands.

(2) FIG. 2 is an isometric view of a portion of an abrasive disk with individual raised islands.

(3) FIG. 3 is an top view of an abrasive disk with an annular band of abrasive coated islands.

(4) FIG. 4 is a top view of a magnetic material abrasive slurry coating font sheet.

(5) FIG. 5 is a side view of a magnetic material abrasive slurry coating font sheet and islands.

(6) FIG. 6 is a side view of a portion of a coating hole font sheet in contact with islands.

(7) FIG. 7 is a side view of an abrasive slurry filled portion of a coating hole font sheet.

(8) FIG. 8 is a side view of a portion of an abrasive slurry coated raised island disk.

(9) FIG. 9 is a side view of a portion of abrasive slurry coated island flattening plate.

(10) FIG. 10 is a side view of a portion of an abrasive disk with spherical beads.

(11) FIG. 11 is a side view of a portion of islands with an integral monolayer of spherical beads.

DETAILED DESCRIPTION OF THE INVENTION

(12) FIG. 1 is an isometric view of an abrasive disk with an annual band of raised islands. A flexible abrasive disk 112 has attached raised island structures 106 that are top-coated with abrasive particles 108 where the island structures 106 are attached to a disk 112 transparent or non-transparent backing 114. The raised-island disk 112 has annular bands of abrasive-coated 108 raised islands 106 where the annular bands have a radial width of 110. Each island 106 has a typical width 102. The islands 106 can be circular as shown here or can have a variety of shapes comprising radial bars, ellipses, diamond shapes, rectangular shapes, hexagons, smooth-corner hexagons and other shapes (all not shown) where the abrasive-coated 108 raised islands 106 allow the abrasive disks 112 to be used successfully at very high abrading speeds in the presence of coolant water without hydroplaning of the workpieces (not shown). There are channel gap openings 104 that exist on the abrasive disk 112 between the raised island structures 106.

(13) For high speed flat lapping or polishing, the abrasive disk 112 has an overall thickness variation, as measured from the top of the abrasive-coated 108 raised islands 106 to the bottom surface of the abrasive disk backing 114, that is typically less than 0.0001 inches 0.254 micron). This abrasive disk 112 precision surface flatness is necessary to provide an abrasive coating that is uniformly flat across the full annular band abrading surface of the abrasive disk 112 which allows the abrasive disk 112 to be used at very high abrading speeds of 10,000 surface feet (3,048 m) per minute or more. These high abrading speeds are desirable as the workpiece material removal rate is directly proportional to the abrading speeds. These abrasive disks are particularly useful for high speed polishing of sapphire wafers and other sapphire components used in cellular phones and sapphire crystals used in watches and sapphire monitor screens used in electronic display devices. In addition these disks provide very substantial production time and cost savings, often well in excess of 10 times reductions, as compared with conventional liquid abrasive slurry lapping and polishing of sapphire devices.

(14) FIG. 2 is an isometric view of a portion of an abrasive disk with individual raised islands. A transparent or non-transparent backing sheet 120 has raised island structures 118 that are top-coated with a solidified abrasive-slurry layer mixture 122 which is filled with abrasive particles 116. The fixed-abrasive coating 122 on the raised islands 118 includes individual abrasive particles 116 or ceramic spherical beads (not shown) that are filled with very small diamond, cubic boron nitride (CBN) or aluminum oxide abrasive particles. The sizes of the abrasive particles 116 contained in the beads ranges from 60 microns to submicron sizes where the smaller sizes are typically used to polish semiconductor wafers.

(15) FIG. 3 is an top view of an abrasive disk with an annular band of individual abrasive coated raised islands. The abrasive disk 150 has an outer diameter 152 and an annular band of abrasive coated raised islands 156 where the annular band has an approximate outer diameter 148 and an approximate inner diameter 146. The abrasive disk 150 has a rotation center 154. The individual islands 156 have island diameters 158. The array of islands 156 shown here is constructed as an rectangular array with a nominal distance 140 between the vertical columns of islands 156 and a distance 142 between repeating horizontal rows of islands 156 and the distance 144 between offset horizontal rows of islands 156.

(16) To provide uniform wear-down of the abrasive coated raised islands 156 the annular band approximate outer diameter 148 is typically 3 times the approximate inner diameter 146 and can range from 1.5 to 6 times the approximate inner diameter 146. The workpieces (not shown) are somewhat larger than the annular width of the abrasive band and overhang both the inner 146 and outer band 148 diameters to provide uniform wear-down of the annular band of raised islands 156 as both the workpiece and the abrasive disk are rotated in the same direction. The pattern of abrasive coated raised islands 156 are shown positioned with a rectangular grid spacing but they can be positioned with a wide range of non-rectangular grid patterns (not shown).

(17) FIG. 4 is an top view of a magnetic material abrasive slurry coating font sheet having a open hole pattern that matches the annular band of individual abrasive coated raised islands shown in FIG. 3. Each of the coating font sheet holes has a corresponding respective raised island flat surfaced structure where the individual hole patterns in the font sheet are slightly smaller than the individual respective top flat surface of the raised island structures. Because of the slightly smaller sizes of the font sheet holes than the island surfaces, the magnetic font sheet is supported by the top surfaces of the raised island structures when the font sheet is positioned in flat surfaced contact with the raised island structures and magnetic forces are imposed on the font sheet by a magnet (not shown).

(18) The coating font sheet 170 has an outer diameter 172 and an annular band of coating font sheet holes 176 where the annular band has an approximate outer diameter 168 and an approximate inner diameter 166. The coating font sheet 170 has a rotation center 174. The individual holes 176 have hole diameters 178. The array of holes 176 shown here is constructed as an rectangular array with a nominal distance 160 between the vertical columns of holes 176 and a distance 162 between repeating horizontal rows of holes 176 and the distance 164 between offset horizontal rows of holes 176.

(19) The pattern of coating font sheet holes 176 are shown positioned with a rectangular grid spacing but they can be positioned with a wide range of non-rectangular grid patterns (not shown). The font sheet holes 176 and the island structures (not shown) have the same relative dimensional coordinates which allows the font sheet holes 176 to be positioned in near-congruent alignment to the respective island structures when the font sheet 170 is positioned in flat surfaced contact with the island top surfaces where the font sheet holes 176 are slightly smaller than the respective island structures flat top surfaces. The coating font sheet holes 176 shapes are shown as circular but they can have many shapes including elliptical, rhombus, pie and rectangular shapes or shape combinations (not shown) and the individual raised island structure shapes can be nominally equal in size or the shapes can be nominally unequal in size.

(20) FIG. 5 is a side view of a magnetic material abrasive slurry coating font sheet having a open hole pattern that that matches the annular band of individual abrasive coated raised islands on an abrasive disk. The coating font sheet 188 has a outer diameter 180 and a uniform thickness 184 with a pattern of holes that extend through the thickness 184 of the font sheet 188. Each hole 186 has a hole shape and hole size where a circular hole 186 can have a hole diameter 182.

(21) FIG. 6 is a side view of a portion of a coating hole font sheet in conformal contact with an abrasive disk with individual raised islands structures. The flexible magnetic coating hole front sheet 196 is positioned in conformal contact with the top flat surfaces of raised island structures 200 that are attached or an integral part of a flexible non-magnetic backing 202 that is a component of an raised island disk substrate 206. A permanent or electro magnet 208 is shown positioned in contact with the bottom surface of the raised island disk substrate 206 but it can also be positioned some distance below the bottom surface of the raised island disk substrate 206. The magnet 208 applies magnet forces 197 that act on the magnetic coating hole front sheet 196 to force the coating hole front sheet 196 tightly against the flat surfaced island structures 200 to effect a liquid seal between the font sheet 196 and the island structures 200 around the periphery of each independent flat surfaced island structure 200.

(22) There is a recessed gap area 204 between each island structure and the structural magnetic steel font sheet bridges across the raised island recessed gap areas 204. The font sheet 196 holes have openings 198 that have dimensions 190 that are smaller than the top flat surfaces of the flat surfaced island structures 200 that have dimensions 192. The font sheet 196 overlaps the individual flat surfaced island structures 200 by a distance 194 around the periphery of each flat surfaced island structure 200 which provides structural support of the font sheet 196. The overlap also provides a liquid seal to prevent leakage of a liquid abrasive and adhesive slurry (not shown) that is introduced into the font sheet 196 holes openings 198. The uniform thickness font sheet 196 has a thickness 195 that establishes the thickness of the abrasive slurry that is coated on the island structure 200 flat surfaces. The flexible non-magnetic backing 202 material can a polymer, aluminum, brass or non-magnetic stainless steel, cloth and woven fiber material or combinations of them.

(23) FIG. 7 is a side view of a abrasive slurry filled portion of a coating hole font sheet in conformal contact with an abrasive disk with individual raised islands structures. The flexible magnetic coating hole front sheet 214 is positioned in conformal contact with the top flat surfaces of raised island structures 218 that are attached or an integral part of a flexible non-magnetic backing 220 that is a component of an raised island disk substrate 224. A permanent or electro magnet 226 is shown positioned in contact with the bottom surface of the raised island disk substrate 224 but it can also be positioned some distance below the bottom surface of the raised island disk substrate 224. The magnet 226 applies magnet forces 215 that act on the magnetic coating hole front sheet 214 to force the coating hole front sheet 214 tightly against the flat surfaced island structures 218 to effect a liquid seal between the font sheet 214 and the island structures 218 around the periphery of each independent flat surfaced island structure 218.

(24) There is a recessed gap area 222 between each island structure and the structural magnetic steel font sheet bridges across the raised island recessed gap areas 222. The font sheet 214 holes have openings that have dimensions that are smaller than the top flat surfaces of the flat surfaced island structures 218. The font sheet 214 overlaps the individual flat surfaced island structures 218 around the periphery of each flat surfaced island structure 218 which provides structural support of the font sheet 214. The overlap also provides a liquid seal to prevent leakage of a liquid abrasive and adhesive slurry 210, 216 that is introduced into the font sheet 214 holes openings.

(25) A bank of excess liquid abrasive slurry 210 is acted upon by a squeegee or flexible doctor blade 212 that is moved across the surface of the uniform thickness font sheet 214 having a thickness 213 that establishes the uniform thickness 213 of the abrasive slurry 216 that is level-coated at each independent island structure 218 flat surface. After the abrasive slurry 216 is deposited at each font sheet 214 hole opening and level-filled with the surface of the flexible uniform thickness font sheet 214 and when the abrasive slurry is non-solidified, partially solidified or fully solidified, the permanent magnet can be removed or the electromagnet can be de-energized and the font sheet 214 can be separated from the raised island disk substrate 224. Each flat surfaced island structures 218 then has a uniform thickness abrasive slurry coating.

(26) In addition, the abrasive slurry 210 can contain at least one filler agent selected from the group consisting of: organic particles, inorganic particles, polymer agglomerates, glass beads, hollow glass beads, and fumed silica or combinations of these filler agents (not shown). Some of the filler agents such as hollow glass beads or spheres can provide increased erodibility of the solidified abrasive slurry 210 that is coated on the independent island structure 218 flat surfaces during abrading action. When the solidified abrasive slurry 210 is abraded, individual abrasive particles or portions of them are exposed for abrading action as the erodibile agents are worn down or worn away by contact with the abraded workpiece (not shown).

(27) The liquid abrasive slurry mixture of abrasive particles and an adhesive binder can also contain thickening agents that include fumed silica, glass beads or inorganic or organic agglomerates which can affect the rheological characteristics of the abrasive slurry coating. Adding select quantities of the fumed silica can make the liquid slurry to have shear-dependent thixotropic characteristics where the liquid slurry does not flow freely unless forces are applied to the slurry. Here the slurry mixture that is contained in the font sheet holes positioned at the sites of the respective island top surfaces forms a uniform thickness of slurry across the full surface of each island. Where a filler such as fumed silica is mixed in the coated slurry mixture, the hole font sheet can be separated from the island tops and each individual island thixotropic slurry coating will retain the respective near-original font hole shapes, cylindrical or other shapes, of the island slurry coating even when the slurry is not partially solidified. Also, use of a thixotropic abrasive slurry prevents leakage of the slurry contained in the font holes to gaps between the font sheet and the island top surfaces. After the font sheet is separated, the thixotropic abrasive slurry can be partially or fully solidified.

(28) FIG. 8 is a side view of a portion of an abrasive slurry coated raised island disk. The abrasive disk 244 has a flexible backing 242 that has attached raised island structures 236 having flat surfaced island tops that are coated with a mixture of an adhesive and abrasive particles 238. The mixture of an adhesive and abrasive particles 238 has an uniform thickness 240 and has an abrasive mixture coating 238 size 230 that is smaller than the island structures 236 dimensional size 232 by a dimensional size difference 234 that extends around the periphery of the individual raised island structures 236.

(29) FIG. 9 is a side view of a portion of an abrasive slurry coated raised island disk with a island top surface flattening plate. The abrasive disk 258 has a flexible backing 256 that has attached raised island structures 250 having flat surfaced island tops that are coated with a slurry mixture of adhesive and abrasive particles 252. The mixture of an adhesive and abrasive particles 252 has an uniform thickness 246 and has an abrasive mixture coating that is smaller than the island structures 236 size that extends around the periphery of the individual raised island structures 236. However, when a magnetic steel font sheet (not shown) is separated from the raised island structures 250 when the slurry mixture of adhesive and abrasive particles 252 is not solidified, some portions of the uniform layer of slurry mixture can become distorted and have a non-flat surface (not shown). An island flattening plate 248 is positioned in flat surfaced contact with the non-solidified or partially solidified mixture of an adhesive and abrasive particles 252 to create an uniform thickness 246 of the mixture of the adhesive and abrasive particles 252. Also, the island flattening plate 248 can be positioned a uniform selected distance from the bottom mounting surface 254 of the abrasive disk 258 flexible backing 256 to provide that the abrasive disk 258 has a uniform thickness 249 across the whole abrading surface of the abrasive disk 258.

(30) FIG. 10 is a side view of a portion of an abrasive disk with an integral monolayer of spherical beads. The spherical beads 268 are filled with abrasive particles (not shown) where the beads 268 are attached to the raised islands 270 by a solvent-based resin adhesive binder 266 that shrinks around the base of the beads 268 when the solvent evaporates from the solvent-based resin adhesive binder 266. There are recessed areas 274 that are adjacent to the raised island structures 270. The abrasive coated islands 262 have adhesive resins 266 that have a solvents that can be selected from water, alcohol, methyl ethyl keytone and toluene or combinations them. When the resin 266 is solidified in an oven, the solvents evaporate and the resin 266 volume is reduced leaving portions of the abrasive particle filled beads 268 exposed for abrading.

(31) FIG. 11 is a side view of a portion of an abrasive disk with an integral monolayer of spherical beads. The spherical beads 282 are filled with abrasive particles 284 where the beads 282 are attached to the raised islands 288 by a solvent-based resin adhesive binder 286 that shrinks around the base of the beads 282 when the solvent evaporates from the solvent-based resin adhesive binder 286. When the resin 286 is solidified in an oven, the solvents evaporate and the resin 286 volume is reduced leaving portions of the abrasive particle filled beads 282 exposed for abrading.

(32) The abrasive font sheet coated raised island disk apparatus and processes to use it are described here. An abrasive raised island disk article comprising:

(33) a) a circular, flexible, non-magnetic backing disk substrate having a backing disk substrate thickness, a backing disk substrate outer diameter, a backing disk substrate first surface, and a backing disk substrate second surface;

(34) b) a nominally-annular pattern of individual raised island structures that are integral to or attached to the backing disk substrate first surface wherein the nominally-annular pattern of raised island structures has an approximate outer diameter and an approximate inner diameter wherein each individual raised island structure has a raised island structure flat surfaced top, a raised island structure flat surfaced top shape, a raised island structure flat surfaced top outer periphery, a raised island structure height, and controlled-size recessed gaps exist between adjacent individual raised island structures;
c) a flexible magnetic material abrasive slurry coating font sheet having a coating font sheet first surface, a coating font sheet second surface, a coating font sheet uniform thickness, a coating font sheet nominally-annular pattern of individual open holes wherein the open holes extend through the thickness of the coating font sheet and wherein each individual coating font sheet hole has a coating font sheet hole shape and a coating font sheet hole shape outer periphery and controlled-size portions of the magnetic font sheet material exist between adjacent individual raised island structures and wherein each individual coating font sheet hole shape is smaller than matching respective individual raised island structure flat surfaced top shapes;
d) wherein the coating font sheet second surface can be placed in flat-surfaced contact with the raised island structures flat surfaced tops wherein the individual coating font sheet hole shapes are near-congruent with the matching respective slightly larger individual raised island structure shapes and wherein the coating font sheet hole shape outer peripheries are positioned a selected distance from the raised island structure flat surfaced top outer peripheries and wherein the controlled-size portions of the magnetic font sheet material that exists between adjacent individual open holes are nominally aligned with the controlled-size recessed gaps that exist between the adjacent matching respective individual raised island structures;
e) a magnet can be placed in contact with the backing disk substrate second surface or positioned a selected distance from the backing disk substrate second surface wherein the magnetic force of the magnet acts upon the magnetic abrasive slurry coating font sheet and urges the magnetic coating font sheet second surface to be in conformal flat-surfaced contact with the raised island structures flat surfaced tops wherein the magnetic font sheet having hole openings that are slightly smaller than the raised island structures flat surfaced tops is structurally supported by the slightly larger raised island structure flat surfaced tops when the magnetic font sheet is subjected by magnetic forces that urge the magnetic font sheet toward the raised island structure flat surfaced tops;
f) a liquid slurry mixture of an adhesive and abrasive particles can be introduced into and completely fill each of the coating font sheet individual open holes wherein the liquid slurry mixture of an adhesive and abrasive particles contacts and becomes attached to each individual raised island structure nominally flat surfaced top surface;
g) a squeegee or flexible doctor blade device wherein the squeegee or doctor blade device can be positioned in contact with the magnetic abrasive slurry coating font sheet first surface and moved across all of the individual abrasive slurry filled holes while in conformal contact with the coating font sheet first surface wherein excess abrasive slurry is removed by the squeegee or doctor blade device from each coating font sheet hole and wherein each of the individual abrasive slurry filled coating font sheet holes is level-filled with the coating font sheet first surface;
h) the liquid slurry mixture of adhesive and abrasive particles contained in all of the individual abrasive slurry filled holes can be partially or completely solidified or non-solidified wherein the coating font sheet can be separated from the nominally-annular pattern of raised island structures flat surfaced tops wherein each of the individual raised island structures nominally flat surfaced top surfaces are coated with a uniform thickness of the slurry mixture of adhesive and abrasive particles;
i) the partially or completely solidified or non-solidified mixtures of adhesive and abrasive particles attached to the individual raised island nominally flat surfaced top surfaced individual raised island structures have a first surface that is adhesively attached to the individual raised island structures flat surfaced tops and have partially or completely solidified or non-solidified mixtures of adhesive and abrasive particles exposed second surfaces that opposes the first surfaces.

(35) Also, the magnet is at least one permanent magnet or at least one electromagnet and the flexible non-magnetic disk backing disk material comprises flexible materials selected from the group consisting of: a polymer, aluminum, brass or non-magnetic stainless steel, cloth and woven fiber material or combinations thereof. Further, the abrasive particles comprises particles selected from the group consisting of: diamond, cubic boron nitride and aluminum oxide or combinations thereof. Also, the abrasive slurry adhesive comprises adhesives selected from the group consisting of: phenol formaldehydes, epoxies and polyurethanes or combinations thereof.

(36) In addition, the abrasive slurry adhesive contains solvents comprising solvents selected from the group consisting of: water, alcohol, methyl ethyl keytone and toluene or combinations thereof. And, a release agent coating can be applied to the coating font sheet wherein the release agent comprises release agents selected from the group consisting of: silicone oil, silicon grease, polytetrafluoroethylene coatings, petroleum jelly, paraffin and mold release agents or combinations thereof. Also, the abrasive slurry can contain at least one filler agent selected from the group consisting of: organic particles, inorganic particles, polymer agglomerates, glass beads, hollow glass beads, and fumed silica or combinations thereof.

(37) Furthermore, the individual raised island structure shapes comprises island shapes selected from the group consisting of: circular, elliptical, rhombus, pie and rectangular shapes or combinations thereof and wherein the individual raised island structure shapes are nominally equal in size or the shapes are nominally unequal in size.

(38) Also, a flat plate can be placed in flat-surfaced conformal contact with the second surfaces of the partially or non-solidified slurry mixture of adhesive and abrasive particles coated on the raised island structures after the coating font sheet is separated from the raised island structures flat surfaced tops wherein contact of all of the second surfaces of the slurry mixture of partially or non-solidified slurry mixture adhesive and abrasive slurry coatings on the individual raised island structures with the flat plate positions all of the adhesive and abrasive slurry coatings into a common plane.

(39) And, the flat plate that contacts the second surfaces of the adhesive and abrasive slurry coatings can be positioned parallel to the backing disk substrate second surface wherein the second surfaces of the slurry mixture of adhesive and abrasive slurry coatings on the individual raised island structures are parallel to the backing disk substrate second surface to provide an abrasive raised island disk article having a uniform thickness measured from the second surface of the adhesive and abrasive particles coated raised island structures to the backing disk substrate second surface.

(40) Further, the solidified mixtures of an adhesive and abrasive particles that are adhesively attached to the individual raised island structures nominally flat surfaced top surfaces can be ground flat to provide an abrasive raised island disk article having a uniform thickness measured from the adhesive and abrasive particles coated raised island structures to the backing disk substrate second surface.

(41) In addition, the raised island structures nominally flat surfaced top surfaces can be ground flat prior to coating the raised island structures nominally flat surfaced top surfaces with the liquid slurry mixture of an adhesive and abrasive particles to provide an abrasive raised island disk article having a uniform thickness measured from the adhesive and abrasive particles coated raised island structures to the backing disk substrate second surface.

(42) Also, a process is described for coating a pattern of flat surfaced raised island structures attached to a flexible backing sheet disk substrate with a liquid slurry mixture of an adhesive and abrasive particles comprising:

(43) a) providing a circular, flexible, non-magnetic backing disk substrate having a backing disk substrate thickness, a backing disk substrate outer diameter, a backing disk substrate first surface, and a backing disk substrate second surface;

(44) b) providing a nominally-annular pattern of individual raised island structures that are integral to or attached to the backing disk substrate first surface wherein the nominally-annular pattern of raised island structures has an approximate outer diameter and an approximate inner diameter wherein each individual raised island structure has a raised island structure flat surfaced top, a raised island structure flat surfaced top shape, a raised island structure flat surfaced top outer periphery, a raised island structure height, and controlled-size recessed gaps exist between adjacent individual raised island structures;
c) providing a flexible magnetic material abrasive slurry coating font sheet having a coating font sheet first surface, a coating font sheet second surface, a coating font sheet uniform thickness, a coating font sheet nominally-annular pattern of individual open holes wherein the open holes extend through the thickness of the coating font sheet and wherein each individual coating font sheet hole has a coating font sheet hole shape and a coating font sheet hole shape outer periphery and controlled-size portions of the magnetic font sheet material exist between adjacent individual raised island structures and wherein each individual coating font sheet hole shape is smaller than matching respective individual raised island structure flat surfaced top shapes;
d) placing the coating font sheet second surface in flat-surfaced contact with the raised island structures flat surfaced tops wherein the individual coating font sheet hole shapes are near-congruent with the matching respective slightly larger individual raised island structure shapes and wherein the coating font sheet hole shape outer peripheries are positioned a selected distance from the raised island structure flat surfaced top outer peripheries and wherein the controlled-size portions of the magnetic font sheet material that exists between adjacent individual open holes are nominally aligned with the controlled-size recessed gaps that exist between the adjacent matching respective individual raised island structures;
e) placing a magnet in contact with the backing disk substrate second surface or positioned a selected distance from the backing disk substrate second surface wherein the magnetic force of the magnet acts upon the magnetic abrasive slurry coating font sheet and urges the magnetic coating font sheet second surface to be in conformal flat-surfaced contact with the raised island structures flat surfaced tops wherein the magnetic font sheet having hole openings that are slightly smaller than the raised island structures flat surfaced tops is structurally supported by the slightly larger raised island structure flat surfaced tops when the magnetic font sheet is subjected by magnetic forces that urge the magnetic font sheet toward the raised island structure flat surfaced tops;
f) providing a liquid slurry mixture of an adhesive and abrasive particles that is introduced into and completely fills each of the coating font sheet individual open holes wherein the liquid slurry mixture of an adhesive and abrasive particles contacts and becomes attached to each individual raised island structure nominally flat surfaced top surface;
g) providing a squeegee or flexible doctor blade device wherein the squeegee or doctor blade device that is positioned in contact with the magnetic abrasive slurry coating font sheet first surface and is moved across all of the individual abrasive slurry filled holes while in conformal contact with the coating font sheet first surface wherein excess abrasive slurry is removed by the squeegee or doctor blade device from each coating font sheet hole and wherein each of the individual abrasive slurry filled coating font sheet holes is level-filled with the coating font sheet first surface;
h) partially or completely solidifying or non-solidifying the liquid slurry mixture of adhesive and abrasive particles contained in all of the individual abrasive slurry filled holes wherein the coating font sheet is separated from the nominally-annular pattern of raised island structures flat surfaced tops wherein each of the individual raised island structures nominally flat surfaced top surfaces are coated with a uniform thickness of the slurry mixture of adhesive and abrasive particles;
i) wherein the partially or completely solidified or non-solidified mixtures of adhesive and abrasive particles attached to the individual raised island nominally flat surfaced top surfaced individual raised island structures have a first surface that is adhesively attached to the individual raised island structures flat surfaced tops and have partially or completely solidified or non-solidified mixtures of adhesive and abrasive particles exposed second surfaces that opposes the first surfaces.

(45) Also, a process is described wherein the magnet is at least one permanent magnet or at least one electromagnet and wherein the flexible non-magnetic disk backing disk material comprises flexible materials selected from the group consisting of: a polymer, aluminum, brass or non-magnetic stainless steel, cloth and woven fiber material or combinations thereof.

(46) In addition, a process is described wherein the abrasive particles comprises particles selected from the group consisting of: diamond, cubic boron nitride and aluminum oxide or combinations thereof. And, the abrasive slurry adhesive comprises adhesives selected from the group consisting of: phenol formaldehydes, epoxies and polyurethanes or combinations thereof.

(47) Furthermore, a process is described wherein the abrasive slurry adhesive contains solvents comprising solvents selected from the group consisting of: water, alcohol, methyl ethyl keytone and toluene or combinations thereof. And, a release agent coating is applied to the coating font sheet wherein the release agent comprises release agents selected from the group consisting of: silicone oil, silicon grease, polytetrafluoroethylene coatings, petroleum jelly, paraffin and mold release agents or combinations thereof.

(48) Further, a process is described wherein a flat plate is placed in flat-surfaced conformal contact with the second surfaces of the partially or non-solidified slurry mixture of adhesive and abrasive particles coated on the raised island structures after the coating font sheet is separated from the raised island structures flat surfaced tops wherein contact of all of the second surfaces of the slurry mixture of partially or non-solidified slurry mixture adhesive and abrasive slurry coatings on the individual raised island structures with the flat plate positions all of the adhesive and abrasive slurry coatings into a common plane and wherein the flat plate that contacts the second surfaces of the adhesive and abrasive slurry coatings is positioned parallel to the backing disk substrate second surface to provide an abrasive raised island disk article having a uniform thickness measured from the second surface of the adhesive and abrasive particles coated raised island structures to the backing disk substrate second surface.

(49) An alternative description of the present invention is as an abrasive raised island disk article having:

(50) a) a circular, flexible, non-magnetic backing disk substrate having a backing disk substrate material, a backing disk substrate thickness, a backing disk substrate outer diameter, a backing disk substrate first surface, and a backing disk substrate second surface;

(51) b) a nominally-annular pattern of individual raised island structures integral to or attached to the backing disk substrate first surface wherein the nominally-annular pattern of raised island structures has an approximate outer diameter and an approximate inner diameter and the individual raised island structures have a raised island structure nominally flat surfaced top surface, a raised island structure nominally flat surfaced top shape, a raised island structure nominally flat surfaced top shape centroid, and a raised island structure height;

(52) c) a flexible magnetic material abrasive slurry coating font sheet having a magnetic coating font sheet first surface, a magnetic coating font sheet second surface, a magnetic coating font sheet uniform thickness, and a magnetic coating font sheet nominally-annular pattern of individual open holes wherein the individual open holes extend through the thickness of the magnetic coating font sheet and wherein the individual open holes have a magnetic coating font sheet open hole shape, a magnetic coating font sheet second surface open hole shape, and a magnetic coating font sheet second surface open hole shape centroid;

(53) d) wherein the pattern of the magnetic coating font sheet individual open holes is approximately the same as the pattern of raised island structures whereby placement of the magnetic coating font sheet second surface in flat-surfaced contact with the raised island structures nominally flat surfaced tops allows individual magnetic coating font sheet open holes to be aligned with respective raised island structures nominally flat surfaced tops where the magnetic coating font sheet second surface open hole shape centroids are in near-coincident alignment with the respective individual raised island structure nominally flat surfaced top shapes centroids and where the magnetic coating font sheet individual open holes are nominally-smaller than the respective raised island structures nominally flat surfaced tops;

(54) e) wherein a magnet placed in contact with the backing disk substrate second surface or positioned a selected distance from the backing disk substrate second surface provides a magnetic force that acts upon the magnetic abrasive slurry magnetic coating font sheet thereby urging the magnetic coating font sheet second surface to be in conformal flat-surfaced contact with the raised island structures nominally flat surfaced tops wherein the magnetic font sheet is structurally supported by the raised island structure nominally flat surfaced tops;

(55) f) a thickenable liquid slurry mixture of an adhesive and abrasive particles filling the magnetic coating font sheet individual open holes wherein the liquid slurry mixture of an adhesive and abrasive particles contacts and attaches to individual raised island structure nominally flat surfaced top surfaces;

(56) g) wherein the liquid slurry mixture filled magnetic coating font sheet open holes are level-filled with the magnetic coating font sheet first surface;

(57) h) the liquid slurry mixture of adhesive and abrasive particles contained in the liquid slurry mixture filled individual open holes wherein the magnetic coating font sheet is separated from the nominally-annular pattern of raised island structures nominally flat surfaced top surfaces leaving the individual raised island structures nominally flat surfaced top surfaces coated with a uniform thickness of the liquid slurry mixture of adhesive and abrasive particles; and

(58) i) the thickenable mixtures of adhesive and abrasive particles contained in the magnetic coating font sheet open holes, when thickened and attached to the individual raised island structure's individual raised island nominally flat surfaced top surface have a thickenable mixture of adhesive and abrasive particles first surface adhesively attached to the individual raised island structures nominally flat surfaced tops and have partially or completely solidified or non-solidified thickenable mixtures of adhesive and abrasive particles exposed second surfaces that opposes the thickenable mixture of adhesive and abrasive particles first surface.

(59) In addition, a process is described wherein the solidified mixture of an adhesive and abrasive particles that are adhesively attached to the individual raised island structures nominally flat surfaced top surfaces are ground flat to provide an abrasive raised island disk article having a uniform thickness measured from the adhesive and abrasive particles coated raised island structures to the backing disk substrate second surface.