JP2006346800A - Vitrified bond grindstone and method of producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vitrified bond grindstone which effectively grinds even a difficult-to-machine material without frequent dressing, to thereby protect a workpiece from degrading, and to provide a method of producing the vitrified bond grindstone. <P>SOLUTION: According to the method, flowable abrasive grain 2 which is obtained by kneading a vitrified bond material containing at least SiO<SB>2</SB>as a main ingredient, an organic bond material, abrasive grain, and liquid together, is impregnated into a sponge member 1 formed of a resin, and the organic bond material and the sponge member are oxidized, followed by sintering the abrasive grain with the vitrified bond material, to thereby form the vitrified bond grindstone having pores. By virtue of formation of the pores, the vitrified bond grindstone easily generates a self-edging function, and therefore frequent dressing is dispensed with, to thereby improve the productivity. Thus by using the vitrified bond grindstone, a ground surface of the workpiece is free from surface burning or tears, and the quality of the workpiece is improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vitrified bond grindstone with a good self-generated blade action and a method for producing the same.

  A wafer on which a plurality of devices such as IC and LSI are formed on the front surface is ground into a predetermined thickness by grinding the back surface, and then divided into individual devices by a dicing apparatus or the like and used for various electronic devices. .

  A wafer to be ground is formed of silicon, silicon nitride, gallium arsenide, sapphire, lithium tantalate, silicon carbide, or the like. On the other hand, there are vitrified bond grindstones, resin bond grindstones, metal bond grindstones, and the like as grinding grindstones. A grindstone suitable for the material of the wafer is selected from these grindstones and used for grinding. Since silicon nitride, sapphire, and silicon carbide have high hardness, when grinding a wafer formed of these materials, a grindstone with a structure in which diamond abrasive grains are firmly held, such as vitrified bond grindstone and metal bond grindstone Is used (see, for example, Patent Document 1).

JP 2003-136410 A

  However, since the self-generated blade action is unlikely to occur on a grindstone with a structure in which abrasive grains are firmly held by vitrified bond or metal bond, clogging occurs in a relatively short time and frequent dressing needs to be performed. There is a problem that productivity is low.

  In addition, due to the fact that the self-generated blade action is less likely to occur, there is a problem that phenomena such as surface burn and stuffiness occur on the ground surface of the workpiece and the quality of the workpiece is reduced.

  Therefore, the problem to be solved by the present invention is to efficiently grind even difficult-to-cut materials without frequent dressing so as not to deteriorate the quality of the object to be ground.

The first invention is a vitrified bond grindstone having pores, wherein fluidized abrasive grains obtained by kneading a vitrified bond material mainly composed of at least SiO ₂ , an organic bond material, abrasive grains, and a liquid are formed of a resin. A sponge member is impregnated to oxidize the organic bond material and the sponge member and to sinter the abrasive grains with the vitrified bond material.

A second invention is a method for producing a vitrified bond grindstone having pores, wherein a flowable abrasive is formed by kneading at least a SiO _{2 based} vitrified bond material, an organic bond material, an abrasive and a liquid. And impregnating sponge body formed by impregnating fluid abrasive grains into a sponge member made of resin having pores, and forming an impregnated sponge body, and evaporating the liquid constituting the impregnated sponge body and solidifying the organic bond material Sintering to form a sintered body having pores by sintering the impregnated sponge body after the solidifying process, oxidizing the organic bond material and the sponge member, and sintering the abrasive grains by vitrified bond material It is characterized by comprising a process.

  In the impregnation sponge body forming step, the abrasive grains are preferably constituted by mixing diamond abrasive grains having a particle size of 2 μm or less with green carborundum or white alundum filler. In the impregnated sponge body forming step, the liquid is preferably composed of water having a weight ratio of 55% and alcohol having a weight ratio of 10%, and the organic bond material is preferably an acrylic bond material having a weight ratio of 5%.

  In the solidification step, the impregnated sponge body is preferably heated at 50 ° C. for 2 hours to evaporate the liquid, and the organic bond material is preferably heated at 120 ° C. for 2 hours to be sintered.

  In the sintering process, the impregnated sponge body after the solidification process is sintered at 400 ° C. for 1 hour to oxidize the organic bond material and the sponge member, and sintered at 700 ° C. for 4 hours to form a sintered body. It is preferable to do.

  After the sintering step, the sintered body may be cut and shaped with a cutting blade to form a grindstone that is fixed to the grinding wheel.

  In the present invention, a vitrified bond grindstone having pores is formed by impregnating the sponge member with fluid abrasive grains and sintering, so that the abrasive grains are easily dropped by the pores, and the self-generated blade action is achieved. Prone to occur. Therefore, clogging is unlikely to occur, and it is not necessary to perform dressing frequently, so even difficult-to-cut materials can be ground efficiently. In addition, since the self-generated blade action is good, the surface of the object to be ground is not burnt or blurred, and the quality of the object to be ground can be improved.

First, a fluidized abrasive grain is formed by kneading a vitrified bond material mainly composed of SiO ₂ , an organic bond material made of an acrylic resin or the like, abrasive grains, and a liquid. As an abrasive grain, a diamond abrasive grain is mentioned as a typical thing. A filler such as green carborundum (green silicon carbide) or white alundum (white alumina) may be mixed. Liquids include water and alcohol.

  Then, as shown in FIG. 1, an impregnated sponge body is formed by impregnating the sponge member 1 formed of a resin such as urethane and having pores with the fluid abrasive grains (impregnation sponge body forming step). For example, as shown in FIG. 2, the fluid abrasive 2 is stored in a container 3, and the sponge member 1 is immersed in the fluid abrasive 2 to impregnate the sponge member 1 with the fluid abrasive.

  Next, the liquid constituting the sponge member 1 impregnated with the flowable abrasive grains 2 is evaporated by heating to solidify the organic bond material contained in the impregnated sponge body (solidification step). Further, the impregnated sponge body in which the liquid is evaporated and the organic bond material is solidified in the solidification step is sintered, the organic bond material and the sponge member are oxidized, and the abrasive grains are sintered by the vitrified bond material. Then, a sintered body having pores is formed, and this sintered body becomes a vitrified bond grindstone.

  For example, as shown in FIG. 3, the formed vitrified bond grindstone 4 is shaped by cutting a cutting blade 5 that rotates at high speed vertically and horizontally along a cutting line 6 into pieces, and a plurality of segmented vitrified particles are formed. The bond grindstone 7 is obtained.

  A plurality of segmented vitrified bond grindstones 7 are fixed to the lower surface of the grinding wheel 814 shown in FIG. 4, for example. And this grinding wheel 814 is used for the grinding apparatus 8 shown, for example in FIG.

  The grinding apparatus 8 includes a chuck table 80 that holds an object to be ground, and a grinding unit 81 that performs grinding on the object to be ground held on the chuck table 80. The grinding means 81 is rotatably supported by a housing 810, and a motor 812 is connected to the upper end of a spindle 811 having a vertical axis, and a grinding wheel 814 is attached to a wheel mount 813 provided at the lower end of the spindle 811. It has been configured. A plurality of segmented vitrified bond grindstones 7 are fixed to the grinding wheel 814, and the grinding wheel 814 is also rotated by the rotation of the motor 812.

  The housing 810 is supported by a support portion 821 connected to the elevating plate 820. The elevating plate 820 is in sliding contact with a guide rail 822 arranged in the vertical direction, and an internal nut (not shown) is vertical. Screwed into a ball screw 823 disposed in the direction. A pulse motor 824 is connected to one end of the ball screw 823. As the ball screw 823 is rotated by the rotation of the pulse motor 824, the elevating plate 820 is guided by the guide rail 822, and the grinding means 81 is also moved up and down. It is the composition to do.

  When grinding the back surface of the wafer W having the protective tape T for protecting the device attached to the surface as in the illustrated example, the front surface side to which the protective tape T is attached is held by the chuck table 80. Then, the chuck table 80 moves in the horizontal direction and is positioned immediately below the grinding means 81. The chuck table 80 rotates, and the grinding means 81 descends while the grinding wheel 814 rotates, so that the segmented vitrified rotates. The bond grindstone 7 contacts the back surface of the wafer W and the back surface is ground.

  Since the segmented vitrified bond grindstone 7 is formed by impregnating and sintering a flowable abrasive grain in a sponge member, a large number of pores are formed inside. Therefore, since the abrasive grains are easy to fall off and the self-generated blade action is good, even when the wafer W is formed of a difficult-to-cut material such as sapphire or silicon carbide, it can be efficiently ground. In addition, since the self-generated blade action is good, the surface to be ground of the wafer is not burnt or blurred, and the quality of the wafer can be improved.

  In the case of self-grinding in which the chuck table 80 is ground so that the upper surface of the chuck table 80 and the lower surface (grinding surface) of the segmented vitrified bond grindstone 7 are aligned, the chuck table 80 is made of a difficult-to-cut material such as silicon carbide. Even if formed, the chuck table 80 can be ground efficiently.

The example of the manufacturing method of a vitrified bond grindstone is shown below. First, in the impregnated sponge body forming step, a vitrified bond containing 35% of diamond abrasive grains each having a volume ratio of 2 μm or less, 5% of green carborundum and white alundum filler, and SiO ₂ as a main component. The material is kneaded at a ratio of 60% to produce a powder kneaded product with a weight ratio of 30%. Then, an acrylic bond material (organic bond material) having a weight ratio of 5%, water having a weight ratio of 55%, and alcohol having a weight ratio of 10% are kneaded to obtain fluid abrasive grains having a weight ratio of 100%. Is impregnated into a sponge member to obtain an impregnated sponge body.

  Next, in the solidifying step, the impregnated sponge body is heated at 50 ° C. for 2 hours to evaporate water and alcohol. Then, the acrylic bond material is solidified by heating at 120 ° C. for 1 hour.

  In the sintering process, the impregnated sponge body after the solidification process is heated at 400 ° C. for 1 hour to oxidize the organic bond material and the sponge member. Furthermore, it sinters at 700 degreeC for 4 hours, and forms a sintered compact. This sintered body becomes a vitrified bond grindstone.

It is a perspective view which shows a sponge member. It is a perspective view which shows the state which immerses the sponge member in a fluid abrasive grain. It is a perspective view which shows the state which shape | molds a sintered compact. It is a perspective view which shows the grinding wheel with which the segment-like vitrified bond grindstone was fixed. It is a perspective view which shows the grinding device carrying the grinding wheel.

Explanation of symbols

1: Sponge member 2: Flowable abrasive grain 3: Container 4: Vitrified bond grindstone 5: Cutting blade 6: Cutting line 7: Segmented vitrified bond grindstone 8: Grinding device 80: Chuck table 81: Grinding means 810: Housing 811 Spindle 812: Motor 813: Wheel mount 814: Grinding wheel 820: Lift plate 821: Supporting part 822: Guide rail 823: Ball screw 824: Pulse motor

Claims (7)

A vitrified bond grindstone having pores,
A sponge member formed of a resin is impregnated with a fluid abrasive particle obtained by kneading at least a SiO ₂ -based vitrified bond material, an organic bond material, abrasive particles, and a liquid, and the organic bond material and the sponge member are impregnated. A vitrified bond grindstone in which the abrasive grains are oxidized and sintered with the vitrified bond material. A method for producing a vitrified bond grindstone having pores,
A fluidized abrasive is formed by kneading a vitrified bond material containing at least SiO ₂ as a main component, an organic bond material, an abrasive and a liquid, and the fluid abrasive is applied to a sponge member formed of a resin having pores. An impregnation sponge body forming step of impregnating and constituting an impregnation sponge body; and
A solidification step of evaporating the liquid constituting the impregnated sponge body and solidifying the organic bond material;
Sintering the impregnated sponge body after the solidification step to oxidize the organic bond material and the sponge member and to sinter the abrasive grains with the vitrified bond material to form a sintered body having pores The manufacturing method of the vitrified bond grindstone comprised from a process.   3. The method for producing a vitrified bond grindstone according to claim 2, wherein in the impregnation sponge body forming step, the abrasive grains are configured by mixing diamond abrasive grains having a particle diameter of 2 μm or less with green carborundum and white alundum fillers.   The said impregnation sponge body formation process WHEREIN: The said liquid is comprised with the water of 55% of weight ratio, and the alcohol of 10% of weight ratio, The said organic substance bond material is an acrylic type bond material of 5% of weight ratio. Method for manufacturing a vitrified bond whetstone.   5. In the solidification step, the impregnated sponge body is heated at 50 ° C. for 2 hours to evaporate the liquid, and the organic bond material is heated at 120 ° C. for 2 hours to be sintered. The manufacturing method of the vitrified bond grindstone of description.   In the sintering step, the impregnated sponge body after the solidification step is sintered at 400 ° C. for 1 hour to oxidize the organic bond material and the sponge member, and sintered at 700 ° C. for 4 hours to perform the firing. The manufacturing method of the vitrified bond grindstone according to claim 2, 3, 4, or 5 which forms a ligature.   The method for producing a vitrified bond grindstone according to claim 2, 3, 4, 5 or 6, wherein after the sintering step, the sintered body is cut and shaped by a cutting blade to form a grindstone fixed to a grinding wheel.

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