Grinding Tool and Method of Fabricating the Same

Abstract

A grinding tool includes a substrate and a plurality of abrasive particles. The substrate has a first and a second surface and a plurality of holes, each of the holes extending through the substrate and respectively having a first and a second opening on the first and second surface, the second opening being larger than the first opening. The abrasive particles are respectively disposed in the holes and attached to the substrate via a plurality of adhesive portions, each of the abrasive particles having a tip protruding outward from the first surface and a remaining part covered with one of the adhesive portions inside the corresponding hole, wherein the first openings of the holes are smaller than the abrasive particles, and the abrasive particles are respectively retained in the holes. Moreover, embodiments described herein include a method of fabricating a grinding tool.

What is claimed is: 
     
         1 . A grinding tool comprising:
 a substrate having a first and a second surface and a plurality of holes, each of the holes extending through the substrate and respectively having a first and a second opening on the first and second surface, the second opening being larger than the first opening; and   a plurality of abrasive particles respectively disposed in the holes and attached to the substrate via a plurality of adhesive portions, each of the abrasive particles having a tip protruding outward from the first surface and a remaining part covered with one of the adhesive portions inside the corresponding hole;   wherein the first openings of the holes are smaller than the abrasive particles, and the abrasive particles are respectively retained in the holes.   
     
     
         2 . The grinding tool according to  claim 1 , wherein each of the holes includes at least a first and a second hole section connected with each other, the first hole section being opened on the first surface through the first opening, and the second hole section being opened on the second surface through the second opening. 
     
     
         3 . The grinding tool according to  claim 2 , wherein each of the holes further includes a third hole section between the first and second hole sections, the third hole section being respectively connected with the first and second hole sections. 
     
     
         4 . The grinding tool according to  claim 2 , wherein the first hole section has a tapered shape that narrows toward the first surface. 
     
     
         5 . The grinding tool according to  claim 4 , wherein a material angle between an inner sidewall of the first hole section and the first surface is between about 70 and about 89 degrees. 
     
     
         6 . The grinding tool according to  claim 2 , wherein the second hole section has an inner sidewall substantially perpendicular to the second surface. 
     
     
         7 . The grinding tool according to  claim 1 , wherein the first opening has a diameter between 0.4 mm and 0.75 mm, and the second opening has a diameter between 1 mm and 2 mm. 
     
     
         8 . The grinding tool according to  claim 1 , wherein the substrate is a single rigid body. 
     
     
         9 . The grinding tool according to  claim 1 , wherein the substrate is made of a metallic material or ceramics. 
     
     
         10 . The grinding tool according to  claim 1 , wherein the abrasive particles are made of diamond, cubic boron nitride, aluminum oxide or silicon carbide. 
     
     
         11 . The grinding tool according to  claim 1 , wherein the abrasive particles have a hexoctahedron crystalline form, and an average greatest width of the abrasive particles is between about 800 μm and about 1000 μm. 
     
     
         12 . The grinding tool according to  claim 1 , further including a base substrate having a surface provided with a cavity, the substrate being disposed in the cavity and attached to the base substrate. 
     
     
         13 . The grinding tool according to  claim 1 , wherein the adhesive portions include epoxy, phenolic resins, polyester resins, polyamide resins, polyimide resins, polycarbonate resins, and any combinations thereof. 
     
     
         14 . A method of fabricating a grinding tool, comprising:
 providing a substrate having a first and a second surface and a plurality of holes, each of the holes extending through the substrate and respectively having a first and a second opening on the first and second surface, the second opening being larger than the first opening;   respectively placing a plurality of abrasive particles in the holes through the second openings thereof, wherein the abrasive particles are generally larger than the first openings and partially protrude outward from the first openings;   placing the substrate on a fixed support having a plurality of positioning cavities, the abrasive particles protruding from the first openings being respectively received partially in the positioning cavities; and   respectively applying a plurality of adhesive portions through the second openings into the holes, thereby the adhesive portions respectively cover the abrasive particles inside the holes and fixedly attach the abrasive particles to the substrate.   
     
     
         15 . The method according to  claim 14 , further including attaching the substrate with the abrasive particles thereon to a base substrate having a surface provided with a cavity, the substrate being disposed in the cavity of the base substrate. 
     
     
         16 . The method according to  claim 14 , wherein the positioning cavities of the fixed support have an accurately controlled depth, and the step of placing the substrate on the fixed support adjusts the positions of the abrasive particles in the holes so that the abrasive particles protrude from the first surface of the substrate with a desirable height. 
     
     
         17 . The method according to  claim 14 , wherein the step of providing a substrate having a first and a second surface and a plurality of holes includes drilling the holes into the substrate, each of the holes including a first and a second hole section connected with each other, the first hole section having a tapered shape and being opened on the first surface through the first opening, and the second hole section having a cylindrical shape and being opened on the second surface through the second opening. 
     
     
         18 . The method according to  claim 14 , wherein the step of providing a substrate having a first and a second surface and a plurality of holes includes drilling the holes into the substrate, each of the holes including a first, a second and a third hole sections connected with one another, the first hole section having a tapered shape and being opened on the first surface through the first opening, the second hole section being opened on the second surface through the second opening, and the third hole section being located between the first and second hole sections. 
     
     
         19 . The method according to  claim 14 , wherein the substrate is a single rigid body. 
     
     
         20 . The method according to  claim 14 , wherein the substrate is made of a metallic material or ceramics.