Grinding wheel manufacturing method

Abstract

To provide a method for manufacturing a grinding wheel, which can omit truing for positioning the ground surfaces of a plurality of grindstones approximately on a same plane or reduce time or labor thereof.SOLUTION: A plurality of grindstones is placed on a machine platen with the other end sides down in a state where one end side of each of the grindstones is inserted into a groove formed on one surface of a base. Thus, the other end surfaces (ground surfaces) of the grindstones can be approximately positioned on a same plane. Therefore, in a grinding wheel including a plurality of such grindstones, truing for positioning the ground surfaces of the grindstones approximately on the same plane can be omitted or time or labor thereof can be reduced.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a grinding wheel that includes an annular base having one surface with an annular groove formed therein, and a plurality of grinding wheels, each of which has one end fixed in the groove. [Background technology]

[0002] Chips for devices such as integrated circuits (ICs) are essential components in various electronic devices such as mobile phones and personal computers. These chips are manufactured, for example, by dividing a wafer on which a large number of devices are formed into regions containing individual devices.

[0003] Furthermore, wafers are often thinned before being divided in order to reduce the size and weight of chips. One method for thinning wafers is to grind the backside of the wafer using a grinding device. This grinding device includes, for example, a chuck table that holds the front side of the wafer, and a grinding unit that is provided above the chuck table and has a spindle with a grinding wheel attached to its lower end.

[0004] A grinding wheel generally includes an annular base having an annular groove formed on one surface thereof, and a plurality of grinding stones, each of which has one end fixed in the groove (see, for example, Patent Document 1). In the grinding wheel, the lower surfaces (grinding surfaces) of the plurality of grinding stones are positioned on approximately the same plane.

[0005] In the grinding device, for example, a chuck table that holds the front side of the wafer and a grinding wheel attached to the lower end of the spindle are both rotated, and multiple grinding wheels are brought into contact with the back side of the wafer, thereby grinding the back side of the wafer and thinning the wafer. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-89065 Summary of the Invention [Problem to be solved by the invention]

[0007] Grinding wheels are generally manufactured by sintering a binder such as a vitrified bond or a resin bond in which abrasive grains such as diamond or cubic boron nitride (cBN) are dispersed. A grinding wheel is then manufactured by fixing multiple grinding wheels to a base in the following order, for example.

[0008] First, a liquid adhesive is supplied to an annular groove formed on one surface of the base. Next, multiple grinding wheels are inserted into the groove so that one end of each grinding wheel is pressed against the bottom of the groove. The liquid adhesive is then dried and hardened. This produces a grinding wheel in which multiple grinding wheels are fixed to the base with one end face of each grinding wheel close to the groove.

[0009] However, the lengths of the grinding wheels often vary due to the temperature and / or humidity distribution in the furnace when the grinding wheels are sintered. When a grinding wheel is manufactured as described above, the positions of the other end faces (grinding surfaces) of the grinding wheels often vary.

[0010] Therefore, in order to position the other end faces (grinding surfaces) of the multiple grinding wheels on approximately the same plane, a process (truing) is sometimes performed to grind the other end sides of the multiple grinding wheels before the grinding wheel is used to grind wafers. However, since the lengths of the multiple grinding wheels vary by 700 μm to 800 μm, truing takes a long time and requires a lot of effort.

[0011] In view of this, an object of the present invention is to provide a method for manufacturing a grinding wheel that can omit or reduce the time and effort required for truing to position the respective grinding surfaces of multiple grinding stones in approximately the same plane. [Means for solving the problem]

[0012] According to one aspect of the present invention, there is provided a method for manufacturing a grinding wheel including an annular base having one surface on which an annular groove is formed, and a plurality of grinding wheels each having one end fixed in the groove, the method comprising: From above the base, which is arranged so that the groove faces upward. a supplying step of supplying adhesive to the groove; and after the supplying step, With the groove facing upward, There is provided a method for manufacturing a grinding wheel, comprising: an inserting step of inserting one end side of each of the plurality of grinding wheels into the groove; a placing step of placing the plurality of grinding wheels on a surface plate with the other end side of each of the plurality of grinding wheels facing downwards while the one end sides of the plurality of grinding wheels remain inserted in the groove after the inserting step; and a curing step of curing the adhesive after the placing step.

[0013] According to another aspect of the present invention, there is provided a method for manufacturing a grinding wheel including an annular base having one surface on which an annular groove is formed, and a plurality of grinding wheels each having one end fixed in the groove, the method comprising: From above the base, which is arranged so that the groove faces upward. a supply step of supplying adhesive into the grooves; a first placing step of placing the plurality of grinding wheels on a surface plate so that the other end side of each of the plurality of grinding wheels faces downward; a second placing step of placing the base on the plurality of grinding wheels while the plurality of grinding wheels remain placed on the surface plate so that the one end side of each of the plurality of grinding wheels is inserted into the grooves, after the supply step and the first placing step; and a curing step of curing the adhesive after the second placing step. In the second placing step, the adhesive does not drip downward from the groove. A method for manufacturing a grinding wheel is provided.

[0014] Furthermore, the adhesive preferably contains a resin.

[0015] Preferably, the adhesive also contains a filler to increase viscosity. [Effects of the Invention]

[0016] In the present invention, the grinding wheels are placed on a surface plate with one end of each wheel inserted into a groove formed on one surface of a base, and the other end faces of each wheel face downwards. This allows the other end faces (grinding surfaces) of the grinding wheels to be positioned on approximately the same plane.

[0017] Therefore, in the case of a grinding wheel manufactured according to the present invention, truing for positioning the grinding surfaces of multiple grinding stones in approximately the same plane can be omitted or the time and effort required for this can be reduced. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1(A) is a top view schematically showing an example of a grinding wheel, FIG. 1(B) is a cross-sectional view schematically showing an example of a grinding wheel, and FIG. 1(C) is a bottom view schematically showing an example of a grinding wheel. [Figure 2] FIG. 2 is a flow chart schematically illustrating an example of a method for manufacturing a grinding wheel. [Figure 3] 3(A), 3(B), 3(C), and 3(D) are cross-sectional views each showing a schematic diagram of each step included in the method for manufacturing the grinding wheel shown in FIG. [Figure 4] FIG. 4 is a flow chart that schematically illustrates another example of a method for manufacturing a grinding wheel. [Figure 5] 5(A), 5(B), 5(C), and 5(D) are cross-sectional views each showing a schematic diagram of each step included in the method for manufacturing the grinding wheel shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described with reference to the accompanying drawings, in which Fig. 1(A) is a top view schematically showing an example of a grinding wheel, Fig. 1(B) is a cross-sectional view schematically showing an example of a grinding wheel, and Fig. 1(C) is a bottom view schematically showing an example of a grinding wheel.

[0020] 1(A), 1(B), and 1(C) has an annular base 4 made of a metal such as an aluminum alloy. The base 4 has a generally flat upper surface (other surface) 4a and a lower surface (one surface) 4b that is narrower in width (length along the radial direction of the base 4) than the upper surface 4a.

[0021] A plurality of screw holes 4c are formed in the upper surface (other surface) 4a at approximately equal intervals along the circumferential direction of the base 4. The grinding wheel 2 is attached to a spindle of a grinding unit provided in a grinding device using bolts that are threaded into each of the plurality of screw holes 4c. In addition, a ring-shaped groove 4d with a rectangular cross section is formed in the lower surface (one surface) 4b of the base 4.

[0022] The width of this groove 4d (the length along the radial direction of the base 4) is, for example, 2 mm to 5 mm, and its depth is, for example, 2 mm. The upper ends (one end sides) of multiple grinding wheels 6 are inserted into this groove 4d so as to be spaced apart from each other along the circumferential direction of the base 4. The grinding wheels 6 have a shape like a rectangular parallelepiped curved with the same curvature as the groove 4d.

[0023] The width of the grinding wheels 6 (the length along the radial direction of the base 4) is, for example, 2 mm to 4 mm. That is, the width of the grinding wheels 6 is 80% to 100% of the width of the grooves in the base 4. Furthermore, the lower end surfaces (grinding surfaces) of the multiple grinding wheels 6 are positioned on approximately the same plane.

[0024] Furthermore, the lengths (the distance between the upper and lower ends) of the grinding wheels 6 are not uniform because the grinding wheels 6 are manufactured through sintering, etc. Therefore, the distance between the bottom surface of the groove 4d of the base 4 and the upper end surfaces of the grinding wheels 6 varies. Furthermore, the grinding wheels 6 are fixed to the groove 4d via hardened adhesive 8.

[0025] The hardened adhesive 8 is obtained, for example, by drying a highly viscous liquid adhesive whose main component is resin. The viscosity of this liquid adhesive is adjusted so that it does not drip downward from the grooves 4d when the grooves 4d are facing downward, and so that it can hold the multiple grinding wheels 6 without dropping when the upper ends of the multiple grinding wheels 6 are inserted into the grooves 4d in this state.

[0026] For example, the viscosity of this liquid adhesive at room temperature is 20 Pa·S to 100 Pa·S. This liquid adhesive may also contain a filler to increase viscosity. Examples of filler materials include white alundum (WA) and other materials whose main component is alumina (Al2O3).

[0027] Fig. 2 is a flow chart showing a schematic example of a method for manufacturing a grinding wheel 2. Also, Fig. 3(A), Fig. 3(B), Fig. 3(C), and Fig. 3(D) are cross-sectional views showing the steps of the method shown in Fig. 2.

[0028] 2, first, adhesive (liquid adhesive) 10 is supplied to an annular groove 4d formed on one surface 4b of the base 4 (supply step: S1). In this supply step (S1), for example, the liquid adhesive 10 is dripped onto the groove 4d from above the base 4, which is arranged so that the groove 4d faces upward (see FIG. 3(A)).

[0029] Next, one end side of each of the plurality of grinding wheels 6 is inserted into the groove 4d (insertion step: S2). In this insertion step (S2), for example, the plurality of grinding wheels 6 are inserted into the groove 4d so that one end side of each of the plurality of grinding wheels 6 is slightly buried in the liquid adhesive 10 (see FIG. 3(B)). At this time, the heights of the other end faces of the plurality of grinding wheels 6 vary due to the fact that the lengths of the plurality of grinding wheels 6 are not uniform.

[0030] Next, with one end of each of the grinding wheels 6 still inserted in the grooves 4d, the grinding wheels 6 are placed on the surface plate 12 with the other end facing downwards (placement step: S3). In this placement step (S3), the weight of the base 4 acts as a force to press the liquid adhesive 10 against the grinding wheels 6.

[0031] As a result, the other end faces (grinding surfaces) of the grinding wheels 6 come into contact with the surface plate 12, and one end side of each of the grinding wheels 6 pushes aside the liquid adhesive 10 and is inserted deeper into the groove 4d. In the placing step (S3), the heights of the other end faces (grinding surfaces) of the grinding wheels 6 that are in contact with the surface plate 12 are made uniform.

[0032] Next, with the grinding wheels 6 still placed on the surface plate 12, the adhesive (liquid adhesive) 10 is cured (curing step: S4). In this curing step (S4), for example, the base 4 and the grinding wheels 6 are left at room temperature for 10 to 14 hours (e.g., 12 hours) or at 70°C to 90°C (e.g., 80°C) for 1 to 3 hours (e.g., 2 hours), thereby drying the liquid adhesive 10 and turning it into a cured adhesive 8 (see FIG. 3(D)). As a result, the grinding wheel 2 is manufactured.

[0033] 2, one end side of each of the plurality of grinding wheels 6 is inserted into a groove 4d formed in one surface of the base 4, and the plurality of grinding wheels 6 are placed on a surface plate 12 with the other end side facing downwards, and adhesive (liquid adhesive) 10 supplied to this groove 4d is cured. In this case, the plurality of grinding wheels 6 are fixed to the base 4 with the other end surface (grinding surface) of each of the plurality of grinding wheels 6 in contact with the surface plate 12.

[0034] That is, the grinding wheel 2 is manufactured with the other end faces (grinding surfaces) of the multiple grinding wheels 6 positioned on approximately the same plane. Therefore, in the grinding wheel 2 manufactured by the method shown in Fig. 2, truing for positioning the grinding surfaces of the multiple grinding wheels 6 on approximately the same plane can be omitted or the time and effort required for truing can be reduced.

[0035] 2 is one embodiment of the present invention, and the present invention is not limited to the method shown in Fig. 2. For example, in the above-mentioned placing step (S3), pressure may be applied downward to the base 4 in order to increase the force with which the liquid adhesive 10 is pressed against the plurality of grinding wheels 6.

[0036] In addition, in the present invention, the liquid adhesive 10 may be cured in a state where the plurality of grinding wheels 6 are not placed on the surface plate 12. That is, in the present invention, after the placing step (S3) is carried out for a predetermined time (for example, 1 hour to 12 hours), the base 4 and the plurality of grinding wheels 6 may be turned upside down and then the liquid adhesive 10 may be cured.

[0037] In the present invention, the grinding wheels 6 may be placed on the surface plate 12 with the other end facing downward, and then one end of each of the grinding wheels 6 may be inserted into the groove 4d of the base 4. Fig. 4 is a flow chart schematically showing an example of a method for manufacturing such a grinding wheel 2.

[0038] 5(A), 5(B), 5(C), and 5(D) are cross-sectional views each showing a schematic diagram of each step included in the method shown in Fig. 4. In the method shown in Fig. 4, similar to the method shown in Fig. 2, first, a supplying step (S1) is carried out (see Fig. 5(A)).

[0039] Next, the grinding wheels 6 are placed on the surface plate 12 so that the other end side of each of the grinding wheels 6 faces downward (first placing step: S5). In this first placing step (S5), the grinding wheels 6 are placed, for example, in an annular area included in the surface plate 12 so that they are spaced apart from each other (see FIG. 5(B)).

[0040] This annular area has a shape corresponding to the groove 4d of the base 4. Furthermore, the surface plate 12 may have marks indicating the positions where the plurality of grinding wheels 6 should be placed.

[0041] In the first mounting step (S5), the heights of the other end faces (grinding surfaces) of the multiple grinding wheels 6, each of which contacts the surface plate 12, are made uniform, and the heights of the one end faces of the multiple grinding wheels 6 vary due to the uneven lengths of the multiple grinding wheels 6.

[0042] Next, while the grinding wheels 6 are still placed on the surface plate 12, the base 4 is placed on the grinding wheels 6 so that one end of each of the grinding wheels 6 is inserted into the groove 4d (second placing step: S6).

[0043] In this second placing step (S6), the weight of the base 4 acts to press the liquid adhesive 10 against the plurality of grinding wheels 6. As a result, one end of each of the plurality of grinding wheels 6 supported on the surface plate 12 pushes aside the liquid adhesive 10 and becomes embedded in the liquid adhesive 10.

[0044] Next, a hardening step (S4) is carried out (see FIG. 5(D)) in the same manner as in the method shown in FIG. 2. As a result, the grinding wheel 2 is produced.

[0045] 2, in the method shown in Fig. 4, the grinding wheel 2 is manufactured in a state in which the other end faces (grinding surfaces) of the multiple grinding wheels 6 are positioned on approximately the same plane. Therefore, in the grinding wheel 2 manufactured by the method shown in Fig. 4, truing for positioning the grinding surfaces of the multiple grinding wheels 6 on approximately the same plane can be omitted or the time and effort required for truing can be reduced.

[0046] 4, the order of the supply step (S1) and the first placing step (S5) is not limited. That is, in the present invention, the supply step (S1) may be performed after the first placing step (S5).

[0047] In the second placing step (S6) described above, pressure may be applied to the base 4 from above downward in order to increase the force with which the liquid adhesive 10 is pressed against the plurality of grinding wheels 6.

[0048] In addition, in the present invention, after the second placing step (S6) is carried out for a predetermined time (for example, 1 hour to 12 hours), the base 4 and the multiple grinding wheels 6 may be turned upside down and then the liquid adhesive 10 may be hardened.

[0049] In addition, the structures and methods according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention. [Explanation of symbols]

[0050] 2: Grinding wheel 4: Base (4a: top surface (other surface), 4b: bottom surface (one surface), 4c: screw hole, 4d: groove) 6: Grinding wheel 8: Adhesive (hardened adhesive) 10: Adhesive (liquid adhesive) 12: Surface plate

Claims

1. A method for manufacturing a grinding wheel including an annular base having one surface on which an annular groove is formed, and a plurality of grinding wheels, each having one end fixed in the groove, comprising: a supply step of supplying adhesive to the groove from above the base, which is arranged so that the groove faces upward; an inserting step of inserting the one end side of each of the plurality of grinding wheels into the groove with the groove facing upward after the supplying step; a placing step of placing the plurality of grinding wheels on a surface plate after the inserting step, with the one end sides of the plurality of grinding wheels still inserted in the grooves, so that the other end sides of the plurality of grinding wheels face downward; a curing step of curing the adhesive after the placing step; A method for manufacturing a grinding wheel comprising:

2. A method for manufacturing a grinding wheel including an annular base having one surface on which an annular groove is formed, and a plurality of grinding wheels, each having one end fixed in the groove, comprising: a supply step of supplying adhesive to the groove from above the base, which is arranged so that the groove faces upward; a first placing step of placing the plurality of grinding wheels on a surface plate so that the other end side of each of the plurality of grinding wheels faces downward; a second placing step, after the supplying step and the first placing step, of placing the base on the plurality of grinding wheels while the plurality of grinding wheels are placed on the surface plate so that the one end side of each of the plurality of grinding wheels is inserted into the groove; a curing step of curing the adhesive after the second placing step, In the second placing step, the adhesive does not drip downward from the groove.

3. 3. The method for manufacturing a grinding wheel according to claim 1, wherein the adhesive contains a resin.

4. 4. The method for manufacturing a grinding wheel according to claim 1, wherein the adhesive contains a filler for increasing viscosity.

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