JP2009006406A - Thin edge grinding wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin edge grinding wheel capable of improving straight moving performance and suppressing generation of chipping when performing machining by sufficiently securing rigidity and strength, even if thickness of an abrasive grain layer is made thinner, and reducing generation of clogging, etc. due to chips in the abrasive grain layer, without impairing sharpness in cutting by heat generated when performing the machining. <P>SOLUTION: This thin edge grinding wheel is provided with a circular thin plate shaped abrasive grain layer 1 constituted by dispersing abrasive grains 4 in a metal plating phase 3. A coating layer 2 made of TiAlN is coated on a side surface 1A of the abrasive grain layer 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a thin blade grindstone used for cutting and grooving various electronic material parts such as semiconductor devices.

As this type of thin-blade grindstone, for example, Patent Document 1 has an annular flat plate-shaped grindstone main body in which abrasive grains are dispersedly arranged in a metal binder phase, and at least in the cutting action region of this grindstone main body, the thickness direction An electroformed thin-blade grindstone in which the protruding amount of the abrasive grains from the surface of the metal binder phase on the side facing the steel is ¼ or less of the average grain diameter of the abrasive grains has been proposed, and at least in this cutting action region, the thickness direction It is described that a high concentration layer having a higher concentration of abrasive grains than that of the intermediate portion is provided at both ends. Patent Document 2 discloses an electrodeposition blade formed by electrodepositing abrasive grains with a base metal, and a coating layer in which diamond-like carbon is coated on the surface of the base metal. The one formed thinner than the grain height has also been proposed.
JP 2004-136431 A JP 2000-144477 A

  By the way, when an electronic material part or the like is cut into pieces by such a thin blade grindstone, it is expected that the cutting margin is made as small as possible to improve the product yield. Also, when grooving electronic parts, grooving at a narrow pitch is often required recently, and therefore the thickness of the abrasive layer for cutting and grooving should be as thin as possible. However, if the abrasive grain layer is made thinner in this way, its rigidity and strength will be lost, and the straightness of the grinding wheel during processing will be deteriorated and processing accuracy will be lost, or large chipping will occur on the workpiece. It may become impossible.

  However, in the thin-blade grindstone described in the above-mentioned Patent Document 1, rigidity is provided by providing high concentration layers on both ends in the thickness direction, that is, on both sides of the abrasive grain layer in the cutting action region of the abrasive grain layer as described above. Although the strength is ensured, the side surface of the metal bonding phase due to nickel plating or the like remains exposed, so that chips generated during processing are likely to adhere and cause clogging, increasing resistance. At the same time, there is a possibility that the grindstone becomes hot during processing and seizure occurs. In this regard, in the thin blade grindstone described in Patent Document 2, since the friction coefficient of diamond-like carbon coated on the surface of the base metal, that is, the side surface of the abrasive grain layer is small, clogging is prevented from occurring on the side surface and at the time of processing However, with such a coating layer made of diamond-like carbon, the rigidity and strength of the abrasive layer cannot be ensured. Moreover, such a diamond-like carbon coating layer is easily peeled off by heat generated during processing, and it is difficult to maintain the effects of preventing clogging and reducing resistance over a long period of time. It is also difficult to improve its own wear resistance.

  The present invention has been made under such a background, and even if the thickness of the abrasive layer is reduced, sufficient rigidity and strength are ensured to improve the straightness during processing and to suppress the occurrence of chipping. Another object of the present invention is to provide a thin blade whetstone that can hardly cause clogging due to chips in the abrasive grain layer and that does not lose sharpness due to heat generated during processing.

  In order to solve the above-described problems and achieve such an object, the present invention includes a circular thin plate-like abrasive grain layer formed by dispersing abrasive grains in a metal plating phase, A coating layer made of TiAlN is coated.

  Therefore, in the thin blade whetstone configured in this way, the coating layer coated on the side surface of the abrasive layer is made of TiAlN having high hardness and high wear resistance, and therefore the entire abrasive layer including the coating layer It is possible to sufficiently ensure rigidity and strength, to improve the straightness of the grindstone during processing, and to suppress the occurrence of chipping on the workpiece. In addition, such a coating layer made of TiAlN does not easily peel off from the metal plating phase in the abrasive grain layer, while the adhesion of chips is low and can prevent clogging and the like. It can prevent seizure and has excellent heat resistance, so it can maintain sharp sharpness even when the temperature rises during processing, and in some cases, it can also be dry-cut or grooved Become.

  Here, the coating layer may be covered over the entire circular side surface of the abrasive layer, but for example, an annular thin plate-like shape that is sandwiched between a pair of flanges and used for processing. In a thin blade grindstone, if the coating layer is coated at least on the outer peripheral side of the flange, the abrasive layer can be reliably indicated via the coating layer. What is necessary is just to coat | cover with the width | variety more than 1/2 of the width | variety of the radial direction of this abrasive grain layer from outer periphery. However, if the coating thickness is so thick that the abrasive grains dispersed from the abrasive layer and protruding from the side surface are buried, there is a risk of increasing resistance during processing and deterioration of sharpness. The coating layer is preferably coated with a thickness of 1/2 or less of the average grain size of the abrasive grains.

  On the other hand, in order to coat such a coating layer made of TiAlN, a CVD method in which coating is performed by reacting with a reactive gas while holding a thin-blade grindstone having an abrasive layer formed by a well-known method in a high-temperature furnace ( (Chemical vapor deposition method) It is also possible, but in such a CVD method, the metal plating phase of the abrasive layer may change in quality due to high temperature and the rigidity and strength of the abrasive layer itself may be impaired. The coating layer is preferably coated by a PVD method (physical vapor deposition method) represented by an ion plating method or a sputtering method.

  Thus, according to the thin-blade grindstone of the present invention, sufficient rigidity and strength can be ensured even if the thickness of the abrasive grain layer is made as thin as possible, thereby improving the straightness of the grindstone and high processing. While obtaining accuracy and suppressing the occurrence of chipping, it is possible to prevent clogging and seizure due to chip adhesion. In addition, the coating layer made of TiAlN is difficult to peel off from the metal plating phase of the abrasive layer and has high heat resistance, so that such effects can be stabilized over a long period of time even under harsh conditions such as dry processing. It is possible to succeed.

  1 to 3 are schematic views showing an embodiment of the thin blade grindstone of the present invention. As shown in FIG. 1, the thin-blade grindstone of the present embodiment is an annular shape centered on the axis O and has a thin plate shape having a thickness of about 0.05 to 0.5 mm. And a coating layer 2 coated on the side surface 1A of the annular thin plate-like abrasive grain layer 1 and the inner diameter part 1B of the abrasive grain layer 1 is not shown in the drawing. While being inserted into the main shaft of the apparatus, the inner peripheral side portion including the coating layer 2 on both side surfaces 1A and 1A is attached to the main shaft by being sandwiched by a pair of flanges or the like. Then, by rotating around the axis O and feeding in a direction perpendicular to the axis O, the outer peripheral edge portion is used for ultra-precision processing such as cutting and grooving of electronic components such as semiconductor chips. .

  The abrasive grain layer 1 is obtained by uniformly dispersing superabrasive grains 4 such as diamond and cBN in a metal plating phase 3 such as Ni, and has a predetermined thickness while incorporating the superabrasive grains 4 on a base metal. After the metal plating phase 3 is deposited, the metal plating phase 3 is formed by a well-known electroforming method by peeling from the base metal and making the side surfaces 1A sharp. On the other hand, in the present embodiment, the coating layer 2 is formed on both side surfaces 1A and 1A of the thus formed abrasive grain layer 1 by ½ the radial width W of the abrasive grain layer 1 from the outer periphery of the abrasive grain layer 1. The above-mentioned constant width X is coated with a substantially constant thickness t equal to or less than 1/2 of the average grain size of the superabrasive grains 4, and is formed by coating TiAlN by the PVD method. . The coating layer 2 made of TiAlN thus coated has the width X and the thickness t substantially equal on both side surfaces 1A and 1A of the abrasive grain layer 1.

More specifically, the coating layer 2 is coated by an arc ion plating method. For example, the abrasive layer 1 formed as described above is masked except for a portion where the coating layer 2 is to be formed, and this is applied to a vacuum. After holding in the chamber and creating a vacuum of 1 × 10 ^{−4 to} 3 × 10 ⁻⁵ Pa, first, high-frequency plasma is generated at an output of 300 W while introducing Ar gas, and −500 V is applied to the abrasive layer 1. The surface is cleaned by applying a DC bias voltage. Next, after applying a pulse bias voltage of −10 kV to the abrasive grain layer 1, nitrogen gas is introduced into the vacuum chamber at a flow rate of 150 to 180 (SCCM), and at the same time as or after generating high-frequency plasma, a TiAl alloy By evaporating the target of (Ti50Al50) by arc discharge with an arc current of about 120 A and adjusting the pulse bias voltage to be applied so as to achieve the predetermined thickness t, for example, by vapor deposition with a processing time of about 100 minutes Covered.

  In the thin blade grindstone thus coated with the coating layer 2, the thickness t of the coating layer 2 is ½ or less of the average grain size of the superabrasive grains 4. The superabrasive grains 4 that have protruded from 1A by more than ½ of the average particle diameter also protrude from the surface of the coating layer 2. Further, after the coating layer 2 is coated, the inner diameter and outer diameter of the thin-blade grindstone are formed to a predetermined diameter. At this time, the coating layer 2 is removed at the outer peripheral edge of the abrasive grain layer 1 and the superabrasive as shown in FIG. The grain 4 is projected.

  Therefore, in the thin blade grindstone of this embodiment formed in this way, the coating layer 2 made of TiAlN coated on the side surface 1A of the abrasive grain layer 1 has higher hardness than the metal plating phase 3 of the abrasive grain layer 1. Because of its high wear resistance, it is possible to ensure sufficient rigidity and strength even if the thickness of the thin blade is reduced as a whole, thereby maintaining the straightness of the thin blade when cutting and grooving. While achieving machining accuracy, it is possible to improve the product yield by reducing the cutting allowance as much as possible, and to reliably cope with grooving with a narrow pitch. In addition, the abrasive layer 1 is thus coated with the hard and highly wear-resistant coating layer 2 made of TiAlN, whereby the wear resistance of the grindstone itself can be improved and the life can be extended.

  Furthermore, such a coating layer 2 made of TiAlN is not easily peeled off by heat generated during processing unlike a coating layer made of conventional diamond-like carbon, that is, because it has high heat resistance, Even sharp cutting and grooving can maintain sharp sharpness. On the other hand, the TiAlN coating layer 2 has less chip adhesion compared to, for example, an abrasive layer with a metal plating phase 3 such as Ni exposed, and thus prevents clogging and the like from occurring. It is possible to promote the reduction of resistance at the time, and to suppress the heat generation during the processing itself and to maintain the sharpness over a longer period.

  Further, in this embodiment, the coating layer 2 is covered from the outer periphery of the abrasive grain layer 1 with a width X that is 1/2 or more of the radial width W of the abrasive grain layer 1, and a thin blade grindstone is sandwiched between a pair of flanges. When being applied, the coating layers 2 and 2 on both side surfaces 1A and 1A of the abrasive layer 1 are sandwiched between the inner peripheral side portions thereof in close contact with the flange. For this reason, cutting and grooving can be performed with these flanges supporting the outer periphery of the thin-blade grindstone through the hard coating layers 2 and 2, and the rigidity and strength of the grindstone itself are ensured as described above. In combination with this, it is possible to further improve the straightness and process with high accuracy.

  The width X only needs to be in such a range that the flange sandwiches the coating layer 2 as described above. For example, the width X is equal to the width W of the side surface 1A of the annular abrasive grain layer 1, that is, The entire surface of the side surface 1A may be configured to be coated with the coating layer 2. However, in the present embodiment, the thin blade whetstone is sandwiched between the pair of flanges as described above. For example, the present invention is applied to a thin blade whetstone with a hub in which the abrasive grain layer 1 is formed on the side surface of an annular base metal. It is also possible to apply.

  On the other hand, in the present embodiment, the coating layer 2 has a thickness t that is 1/2 or less of the average grain size of the superabrasive grains 4, and the average grain size is measured from both side surfaces 1A of the abrasive grain layer 1 as described above. The superabrasive grains 4 protruding more than 1/2 are projected from the surface of the coating layer 2 as they are, and for this reason, there is a slight gap between the processed wall surface during cutting and grooving and the surface of the coating layer 2. But clearance can be secured. Accordingly, resistance during processing can be further reduced, and chips can be smoothly discharged through this clearance, so that occurrence of clogging and the like can be prevented more reliably. However, if the thickness t of the coating layer 2 is too small, it may be difficult to ensure rigidity and strength. Therefore, the thickness t is 1/5 or more of the average grain size of the abrasive grains, or 1.0 μm or more. It is desirable that

  Furthermore, in the present embodiment, the coating layer 2 made of TiAlN is coated by the PVD method, and the abrasive layer 1 is not exposed to a high temperature when the coating layer 2 is coated. The metal plating phase 3 of the abrasive grain layer 1 is not altered by high temperature, and the rigidity and strength of the abrasive grain layer 1 itself are not impaired. Accordingly, it is possible to prevent a situation in which the rigidity and strength of the thin blade grinding wheel as a whole are impaired despite the coating layer 2 being coated, and even more reliably even if the grinding stone thickness is reduced. High-precision machining is possible, and cutting allowance can be reduced and grooving at a narrow pitch can be achieved.

  Hereinafter, the thin-blade grindstone of the present invention will be described with more specific examples. In this example, first, an abrasive grain layer 1 having an outer diameter of 78 mm, an inner diameter of 40 mm, and a thickness of 0.1 mm in which diamond superabrasive grains having an average grain diameter of 14 μm (grain size # 800) are uniformly dispersed in the Ni plating phase at a concentration of 100. Was manufactured as a base blade. Subsequently, the coating layer 2 made of TiAlN having a thickness t of 7 μm, 3 μm, and 10 μm is coated on both side surfaces 1A and 1A of the abrasive layer 1 of the base blade by the PVD method using the arc ion plating method under the conditions described above. Thus, three kinds of thin blade grinding wheels based on the present invention were manufactured. These are referred to as Examples 1 to 3 in the order of the thickness t. In Examples 1 to 3, the width X of the coating layer 2 from the outer periphery of the grindstone was 9.5 mm which is 1/2 of the width W of the abrasive grain layer 1 = 19 mm.

  Here, first, the rigidity values of these Examples 1 to 3 and the base blade not coated with the coating layer 2 as a comparative example were measured. The results are shown in Table 1 below.

  From Table 1, in Examples 1 to 3 where the coating layer 2 is coated, the rigidity value is higher than that of the base blade, and the rigidity value increases as the thickness t of the coating layer 2 increases. I understand.

Next, the same workpiece was cut by these Examples 1 to 3 and the thin blade grindstone of the base blade while changing the feed speed, and the straightness, chipping, and the spindle current value of the cutting device at that time were measured. Here, the cut workpiece is Al ₂ O ₃ —TiC (φ3 ″ × 1.8 t), and a thin blade grindstone is sandwiched between the spindles of a cutting device (made by Fujikoshi Co., Ltd., model number SPG-25) with a flange having an outer diameter of 70 mm. Then, cutting was carried out at feed speeds of 100 mm / min and 300 mm / min while adjusting the spindle current value so that the spindle speed was 15000 min ⁻¹ . The case is shown in Table 2, and the case where the feed rate is 10 mm / sec is shown in Table 3. However, for the straightness, the maximum bending amount (the maximum displacement amount in the cutting width direction) during the cutting length of the workpiece is measured, Moreover, the result of having measured the magnitude | size with the tool microscope about chipping is shown.

  From the results in Tables 2 and 3, the thin blade whetstone of the base blade as a comparative example, when the feed rate is either 100 mm / min or 300 mm / min, the maximum straight amount of bending, the size of chipping, the spindle current Both values were larger than those of Examples 1 to 3, and in particular, when the feed rate was tripled to 300 mm / min, it was impossible to cut due to seizing on the way and measurement was impossible. On the other hand, in the thin-blade grindstones of Examples 1 to 3 according to the present invention, the maximum straight amount of bending and chipping are suppressed to a level that causes no problem, and the spindle current value is small, that is, cutting is performed with low resistance. It was possible, and even when the feed rate was 300 mm / min, cutting was not impossible.

  Further, when these Examples 1 to 3 are compared with each other, the main axis current value is not significantly different between Examples 1 and 2, whereas the thickness t of the coating layer 2 is the average particle diameter of the superabrasive grains 4. It can be seen that Example 3, which was made larger than 1/2, was larger than Examples 1 and 2, that is, the resistance was higher. Further, the straightness and chipping are also larger in the third embodiment than in the first and second embodiments, and in the first and second embodiments, the coating layer 2 is provided with a sufficient thickness t. However, good results were obtained.

  Next, in the same manner as described above, diamond superabrasive grains having an average particle diameter of 12 μm (grain size # 1000) were uniformly dispersed in the Ni plating phase with a concentration of 75, and an abrasive having an outer diameter of 58 mm, an inner diameter of 40 mm, and a thickness of 0.05 mm The grain layer 1 is manufactured as a base blade, and the thickness t is 6 μm, 3 μm, 9 μm on both side surfaces 1A, 1A of the abrasive layer 1 of this base blade by the PVD method using the arc ion plating method under the same conditions as described above. Three types of thin blade grindstones according to the present invention were manufactured by coating the coating layer 2 made of TiAlN. Let these be Examples 4-6 in order of the said thickness t. In Examples 4 to 6 as well, the width X of the coating layer 2 from the outer periphery of the grindstone was 2/3 of the width W = 9 mm of the abrasive grain layer 1 as in Examples 1 to 3.

And while measuring the rigidity value with the thin blade grindstone of these Examples 4-6 and the thin blade grindstone of the said base blade which does not coat | cover the coating layer 2 as a comparative example, width 100mm, length 100mm, thickness Using a 3.0 mm ceramic grease sheet as a workpiece, the spindle current value is adjusted so that the spindle rotation speed is 30000 min ⁻¹ and cutting is performed at a feed rate of 100 mm / sec. Was measured in the same manner as in Examples 1 to 3 above, and the presence or absence of chip adhesion to the thin blade grindstone after cutting was visually confirmed. The results are shown in Table 4 for the rigidity values, and in Table 5 for the straightness, spindle current value, and chip adhesion.

  From the results of Table 4, the stiffness values of Examples 4 to 6 coated with the coating layer 2 are all higher than that of the base blade, as in Examples 1 to 3 and the comparative base blade. As the thickness t of the layer 2 increases, the rigidity value also increases. Furthermore, also from the results of Table 5, with respect to the maximum bend amount and the spindle current value for straightness, the base blade as a comparative example is the maximum, and the thickness t of the coating layer 2 is large Example 6 and the small Example 5 The intermediate thickness t decreases in the order of the fourth embodiment, but the tendency that the spindle current value is the same in the fourth and fifth embodiments is the same as described above. In addition, as for chip adhesion, the base blade of the comparative example was the most, followed by Example 6 to which some adhesion was recognized, and Examples 4 and 5 were not recognized.

It is a side view which shows one Embodiment of this invention. It is ZZ sectional drawing in FIG. It is an enlarged view which shows the outer periphery part periphery of sectional drawing shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Abrasive grain layer 1A Side surface of abrasive grain layer 1 2 Coating layer 3 Metal plating phase 4 Super abrasive grain (abrasive grain)
W Radial width of abrasive layer 1 X Radial width of coating layer 2 t Thickness of coating layer 2

Claims (4)

  A thin-blade grindstone comprising a circular thin plate-like abrasive grain layer in which abrasive grains are dispersed in a metal plating phase, and a coating layer made of TiAlN coated on the side surface of the abrasive grain layer.   2. The thin-blade grindstone according to claim 1, wherein the coating layer is coated with a width of ½ or more of a radial width of the abrasive grain layer from an outer periphery of the abrasive grain layer.   The thin-blade grindstone according to claim 1 or 2, wherein the coating layer is coated with a thickness of ½ or less of an average particle diameter of the abrasive grains.   The thin-blade grindstone according to any one of claims 1 to 3, wherein the coating layer is coated by a PVD method.

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