JPH07100303B2 - Manufacturing method of ultra-thin blade whetstone with hub - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing an ultra-thin blade grindstone with a hub, which is used for cutting and dividing a semiconductor element, super-precision grooving of a magnetic head and the like.

"Prior Art" FIG. 5 is a cross-sectional view showing an example of an ultrathin blade grindstone with a hub of this type.

This grindstone is composed of a thin ring-shaped abrasive grain layer 1 in which superabrasive grains are dispersed in a metal plating phase, and an annular aluminum grain having a smaller diameter than the abrasive grain layer 1 bonded to one surface of the abrasive grain layer 1. Made hub 2
Consists of.

Such a grindstone with a hub was developed for the purpose of enabling automatic mounting on a grindstone driving device. Normally, the fixed portion 2A on the other surface side of the hub 2 is automatically mounted by a grindstone mounting mechanism. The product is chucked, inserted into the spindle of the grindstone drive device, and fixed for use.

In the case of manufacturing the above grindstone, conventionally, the following method is generally adopted.

First, as shown in FIG. 6, an aluminum hub 2 having a flange portion 2B having a constant thickness on the outer periphery on one end face side is prepared, and only the portion where the abrasive grain layer 1 is to be formed is left on the other portion. Apply masking. Next, this is set in a plating apparatus, and while superposing a metal plating phase such as Ni or Co on the end face on the flange portion 2B side, superabrasive grains are dispersed therein to form the abrasive grain layer 1.

Next, the hub 2 is taken out, the outer periphery of the abrasive grain layer 1 and the flange portion 2B is ground, and then both end faces of this whetstone master are held by a masking jig. Then, in this state, the whole is immersed in an alkaline etching solution that does not act on the abrasive grain layer 1, the entire outer periphery of the hub 2 is melted as shown by the chain double-dashed line in FIG. Cutting edge part 1A of grain layer 1
Expose. Then, final finishing is performed to obtain an ultrathin blade grindstone with a hub.

"Problems to be solved by the invention" By the way, in the above-mentioned grindstone manufacturing method, when the cutting edge portion 1A is exposed, the hub fixed portion 2A is also melted at the same time, so that the etching conditions may be slightly changed. It is inevitable that the dissolution amount T in the fixed portion 2A slightly varies.

Therefore, a dimensional error occurs in the diameter D of the fixed portion 2A, and the chucking by the grindstone mounting mechanism is likely to be incomplete. 3 The deterioration of the rotational balance due to the deterioration of the mounting accuracy greatly affects the grinding accuracy. There is also a problem that automatic mounting may fail.

"Means for Solving Problems" The present invention has been made to solve the above problems. One end surface has a larger diameter than the other end surface, and the end portion on the other end surface side is a fixed portion. After electrodepositing an abrasive grain layer formed by dispersing superabrasive grains in a metal plating phase into a thin annular shape on the one end surface of the annular hub, only the outer peripheral portion of the hub on the abrasive grain layer side is melted. The blade edge portion of the abrasive grain layer is exposed to prevent the dimensional error due to melting from occurring in the fixed portion of the hub.

[Example] Hereinafter, an example of a method for manufacturing an ultra-thin blade grindstone with a hub according to the present invention will be described in the order of steps with reference to the drawings.

FIG. 1 is a cross-sectional view of a plating apparatus used when electrodepositing an abrasive grain layer 11 on a hub 10, where reference numeral 20 is a plating tank, 21 is a mask jig for masking the hub 10, and 22 Is the anode. The hub 10 used in this example is made of an amphoteric metal such as aluminum as in the conventional product, but its shape is slightly different, and the width of the flange portion 10A formed on the outer periphery on one side is wider than that of the conventional product. Also, the fixed portion 10B has already been molded to the final product size.

The mask jig 21 has a metal shaft 24 having a resin mask upper plate 23 fixed in the middle thereof, and a resin bottomed cylindrical shape slidably passed through the lower end of the shaft 24. A lower mask body 25 and a resin screw 26 that locks the lower mask body 25 on the shaft body 24.
The surface of the shaft body 24 exposed to the outside of the jig is insulated by paint or the like. Then, the shaft 24 has a flange portion.
After inserting the hub 10 with 10A facing upward, further inserting the mask lower body 25 and tightening with the screw 26,
The O-ring 27 attached to the lower surface of the mask upper plate 23 and the O-ring 28 fixed to the upper end surface of the mask lower body 25 are connected to the hub 10.
Is pressed to expose only the portion of the hub 10 where the abrasive grain layer 1 is to be formed, and the other portions are liquid-tightly shielded.

Now, in order to perform plating with the above apparatus, superabrasive grains are added to the plating solution M in the plating tank 20 and stirred with a stirring device,
The shaft 24 of the jig 21 having the hub 10 mounted thereon is connected to the cathode of the power source, and electricity is supplied between the hub 10 and the anode plate 22. And hub
Superabrasive grains are dispersed while depositing a metal plating phase on the end faces of 10 to form an abrasive grain layer 11 having a predetermined thickness (several tens to 100 μm).

Next, the hub 10 is taken out, and the abrasive grain layer 11 and the flange portion are removed.
After grinding the outer periphery of 10A, the etching jig 3 shown in FIG.
Attach to 0. Like the above-mentioned jig, this jig 30 is composed of a shaft body 32 to which a mask upper plate 31 is fixed, a mask lower body 33 slidably attached to the lower end portion of the shaft body 32, and a smelt 34. When the hub 10 on which the abrasive grain layer 11 is formed and the mask lower body 33 are inserted into the body 32 and the screw 34 is tightened, the elastic mask 35 attached to the screw 34 urges the mask lower body 33 upward, and The O-ring 36 on the lower surface of the plate 31 and the O-ring 37 on the upper end surface of the mask lower body 33 are
By sandwiching the same portion of the flange portion 10A from above and below, only the outer peripheral portion where the cutting edge portion (11A) is to be exposed is exposed to liquid-tightly shield other portions of the grinding stone prototype.

Next, in this state, the jig 30 is added to the alkaline etching solution E.
And melt only the outer periphery of the flange portion 10A. Then, after etching the thickness of the flange portion 10A, it is taken out from the etching solution E, and the blade tip portion 11A of the grindstone thus obtained is lightly etched to perform dressing, and an ultrathin blade grindstone with a hub shown in FIG. To get

In the grinding stone manufacturing method as described above, the flange portion 10A
The fixed part 10B of the hub 10 is
Since it is shielded by and is not melted, the dimensional accuracy of the fixed portion 10B is maintained at high accuracy during machining. Therefore, in the grindstone manufactured by this method, chucking does not become incomplete during mounting by the automatic mounting mechanism, deterioration of rotation balance due to eccentricity, etc. can be prevented, and grinding accuracy can be improved. it can.

Further, according to this method, the thin flange portion 10A is manufactured at the time of manufacturing.
Since it is only necessary to dissolve the outer peripheral portion of the hub, the etching amount can be reduced compared with the conventional method (see FIG. 7) in which the entire outer peripheral portion of the hub needs to be etched, and the manufacturing efficiency can be improved.

Furthermore, since the grindstone manufactured by this method reinforces the cutting edge portion 11A of the abrasive grain layer 11 by the flange portion 10A left as shown in FIG. 3, it is possible to increase the apparent cutting edge amount. For example, even when a cut is made in a deep recess of the work material W as shown in FIG. 4, the hub 10 does not easily interfere with the work material W.

In the above example, the flange 10A uses the hub 10 having a constant thickness and a wide width, but the shape of the hub is not limited to this, the same as the conventional one, or the flange becomes slightly thinner toward the outer peripheral side. It may have a shape or the like.

"Effects of the Invention" As described above, in the method for manufacturing an ultra-thin blade grindstone with a hub of the present invention, since the fixed portion of the hub is not melted during the etching operation of the flange portion, the dimensional accuracy of the fixed portion is increased. Is maintained with high precision during machining. Therefore, according to this method, chucking does not become incomplete during mounting by the automatic mounting mechanism, deterioration of the rotational balance due to eccentricity, etc. is prevented, and in turn the grinding wheel can be manufactured with high accuracy. It is possible.

[Brief description of drawings]

FIG. 1 is a sectional view of a plating apparatus used in an embodiment of a method for manufacturing an ultrathin blade grindstone with a hub of the present invention, FIG. 2 is a sectional view of an etching apparatus used in the method, and FIG. 3 is the same. Sectional view showing an ultra-thin blade grindstone with a hub manufactured by the method,
FIG. 4 is a sectional view at the time of grinding showing the effect of the grindstone. Further, FIG. 5 is a sectional view of a conventional ultra-thin blade grindstone with a hub, and FIGS. 6 and 7 are sectional views for explaining a manufacturing process of a conventional product. 10 …… Hub, 10A …… Flange part, 10B …… Fixed part, 11 …… Abrasive layer, 20 …… Plating bath, 21 …… Mask jig (during plating), 22 …… Anode plate, 30… … Mask jig (during etching).

Claims (1)

[Claims] 1. A super-abrasive grain is dispersed in a metal plating phase on the one end surface of an annular hub having one end surface having a larger diameter than the other end surface and the end portion on the other end surface side being a fixed portion. After electrodepositing the abrasive grain layer formed into a thin annular shape, the hub has an extremely thin blade grindstone characterized in that only the outer peripheral portion of the hub on the abrasive grain layer side is melted to expose the edge portion of the abrasive grain layer. Manufacturing method.