Abrasive article with uniform height abrasive particles

Abstract

A method of making an abrasive article including the step of preparing a master plate with a surface having a shape. Depositing a spacer layer on the surface of the master plate. A slurry containing an adhesive and abrasive particles is deposited on a surface of the spacer layer. A substrate embedded with abrasive particles having a surface generally complementary to the surface of the master plate is fabricated. A spacer layer is formed by various method controlled the height of the protruded abrasive particles. The master plate and the spacer layer are separated from the substrate to expose abrasive particle protruding a substantially uniform height. An abrasive article made according to this method is also disclosed.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefits of the filing date of U.S. Provisional Patent Application Ser. No. 61 / 187,658 filed Jun. 16, 2009, which is entitled “Abrasive Article with Uniform Height Abrasive Particles” which is hereby incorporated herein in its entirety by reference.FIELD OF THE INVENTION[0002]The present application is directed to an abrasive article with abrasive particles that protruded a substantially uniform height above a reference surface, and a method of making and using the same. The present method permits the manufacture of abrasive articles with micron and nano-scale diamond particles.BACKGROUND OF THE INVENTION[0003]Read-write heads for disk drives are formed at the wafer level using a variety of deposition and photolithographic techniques. Multiple sliders, up to as many as 40,000, may be formed on one wafer. The wafer is then sliced into slider bars, each having up to 60-70 sliders. The slider bars are lapped to po...

AI Technical Summary

Benefits of technology

"The present patent is about an abrasive article with uniform height abrasive particles and a lubricant film. The abrasive particles are embedded in a substrate and protrude above the substrate surface. The method allows for precise control of the abrasive particles' height and the hydrodynamic film of lubricant. The abrasive article can be used in various applications such as machining metal parts, silicon wafers, and hard disk drives. The invention also provides a method for lapping surfaces with the abrasive article. The technical effects include improved material removal, reduced wear on the substrate, and improved surface quality."

Problems solved by technology

Current processes are economically wasteful since over 90 percent of the diamonds are lost and unrecoverable in the process.

Large preloads exacerbate scratches on the slider bars caused by peaks on the lapping plate.

Nano-diamonds are difficult to embed in the tin plate.

The risk of free diamonds damaging the slider bar increases.

Slider bars with trailing edges composed of metallic layers and ceramic layers present very severe challenges during lapping.

The variable polishing rates of the metallic and ceramic materials lead to severe recessions, sensor damage, and other problems.

The diamond-charged plates cause large transducer protrusion and recession variations, contact detection area variation, substrate recession, microscopic substrate fractures leading to particle release during operation of the disk drive, scratches from free diamonds, and transducer damage.

Forming the first substrate 11 with sub-micron sized recesses 12 and then inserting sub-micron size abrasive grains, however, is not currently commercially viable.

Sorting sub-micron sized abrasive grains is also problematic.

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