KR20150119806A - Grinding machine - Google Patents

Abstract

The present invention aims to make it possible to continuously grind and to prevent the occurrence of a lot of consumables by grinding. The grinding machine (1) of the present invention comprises: an ultrasonic cleaning nozzle (5) which comprises: a spray nozzle main frame (52) for spraying a cleaning solution (51) to a grinding wheel (41); a cleaning solution supply unit (53) for supplying the cleaning solution to the spray nozzle main frame; an ultrasonic vibrator (55) for giving ultrasonic wave to the cleaning solution supplied by the cleaning solution supply unit; and, a power supply means (56) for applying an AC power to the ultrasonic vibrator. The ultrasonic cleaning nozzle is placed to spray the cleaning solution with ultrasonic wave toward a grinding surface (42a) of a grinding stone (42) which grinds an object to be processed (W). The vibration frequency of the ultrasonic vibrators is set to be 450 kHz to 1.0 MHz.

Description

GRINDING MACHINE

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grinding apparatus capable of grinding a workpiece in contact with a grinding stone.

Various kinds of workpieces such as semiconductor wafers, sapphire, and SiC are ground by a grinding apparatus to be formed into a predetermined thickness and then divided into devices. In the grinding apparatus, the workpiece is ground by bringing the grinding surface of the grinding wheel rotating relative to the workpiece into contact. If this grinding is carried out, clogging of the grinding surface tends to occur, and the grinding ability is lowered due to the clogging of the grinding hole. Therefore, it is necessary to frequently dress the grinding surface. In addition, when abnormal abrasion due to hole collapse is likely to occur in a grinding stone such as grinding of a hard material such as sapphire or SiC, the dressing board is pressed to the grinding area of the grinding wheel during grinding of the workpiece, (See Patent Document 1).

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 11-189456

However, in the case of dressing by pressing the dressing board, it is necessary to replace the dressing board regularly. There is a problem that grinding by the grinding stone is stopped at the time of this exchange work, and the continuous processability is lowered. In addition, there is a problem that a large amount of the dressing board is required, and the cost is increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a grinding apparatus capable of continuously grinding by a grinding means and preventing a large amount of consumables from being generated.

A grinding apparatus of the present invention is a grinding apparatus including grinding means having a grinding wheel for grinding a workpiece held on a holding table and a holding table for holding and rotating the workpiece, An ultrasonic cleaning nozzle composed of a nozzle body, a cleaning liquid supply part for supplying a cleaning liquid to the spray nozzle body, an ultrasonic vibrator for applying ultrasonic waves to the cleaning liquid supplied from the cleaning liquid supply part, and electric power supply means for applying AC power to the ultrasonic vibrator , And the ultrasonic cleaning nozzle is arranged to jet the cleaning liquid to which the ultrasonic wave is applied toward the grinding surface of the grinding wheel of the grinding wheel grinding the workpiece, and the vibration frequency of the ultrasonic vibrator is set to 450 kHz to 1.0 MHz do.

According to this configuration, the ultrasonic waves are applied to the cleaning liquid in the range of the vibration frequency, and the cleaning liquid to which the ultrasonic waves are applied is sprayed to the grinding surface of the grinding stone under grinding, so that the adherence of the grinding surface can be efficiently removed. This eliminates the need for dressing by the dressing board and reduces the cost of preparing consumables such as a large number of dressing boards and the like. In addition, it is not necessary to stop the grinding for replacement of the dressing board, and the continuous processability can be improved.

According to the present invention, since the cleaning liquid to which the ultrasonic waves are applied in the range of the vibration frequency is jetted onto the grinding surface of the grinding stone during grinding, grinding by the grinding means can be performed continuously and a large amount of consumables .

1 is a front schematic view of a grinding apparatus according to the present embodiment.
2 is a graph showing a result of measurement of the consumption amount of the grinding stone.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a schematic front view of a grinding apparatus according to an embodiment.

1, the grinding apparatus 1 includes a holding table 3 and a grinding means 4. The grinding means 4 is provided with a workpiece W). An ultrasonic cleaning nozzle 5 is provided on the right side region of the holding table 3 in Fig.

As the workpiece W in the grinding apparatus 1, it is possible to employ a plate-like workpiece constituted by a hard and hard cutting material. The workpiece W is made of a material such as borosilicate glass, a semiconductor wafer, sapphire, silicon carbide (SiC), or the like.

The holding table 3 has a disk shape and a holding surface 3a for holding and holding the workpiece W is formed on the upper surface thereof. The holding surface 3a is made of, for example, a porous ceramic material, and the porous ceramic material is connected to a suction source (not shown). The holding table 3 is rotatably provided around a shaft orthogonal to the holding surface 3a by a rotating means 31 constituted by a motor or a gear structure not shown.

The grinding means 4 is constituted by providing a grinding wheel 42 on the lower surface of a grinding wheel 41 having a generally disk shape. The grinding wheel 41 is connected to the spindle 43 and configured to be rotatable about the center of the disk of the grinding wheel 41 by the spindle 43. [ The grinding wheel 42 is made of, for example, a diamond grindstone hardened with a coupling agent such as vitrified bond or resin bond. The grinding means 4 is configured to be movable in an orthogonal two-axis or three-axis direction including a vertical direction by a moving mechanism (not shown).

While the grinding wheel 42 is rotating at a high speed, the lower surface becomes the grinding surface 42a, and is brought into contact with the work W and ground. During this grinding, the center of rotation of the grinding wheel 41 is shifted in the rightward direction in Fig. 1 with respect to the center of rotation of the holding table 3. The grinding by the grinding wheel 42 is performed from the left side with respect to the center of rotation of the grinding wheel 41 and the approximately right half area of the grinding wheel 42 is exposed toward the bottom.

The ultrasonic cleaning nozzle 5 includes a jet nozzle body 52 for jetting the cleaning liquid 51 from the tip and a cleaning liquid supply portion 53 for supplying the jetting liquid 51 to the jet nozzle body 52. As the cleaning liquid supply unit 53, a pump or the like can be exemplified. Further, the cleaning liquid 51 means pure water or cleaning water containing a cleaning agent.

The ultrasonic cleaning nozzle 5 further includes an ultrasonic vibrator 55 provided inside the spray nozzle body 52 and electric power supply means 56 for applying AC power to the ultrasonic vibrator 55. [ The ultrasonic vibrator 55 is provided to apply ultrasonic vibration to the cleaning liquid 51 supplied from the cleaning liquid supply unit 53 by the applied AC power.

An arrangement point of the ultrasonic cleaning nozzle 5 is set at a position adjacent to the holding table 3 and below the grinding wheel 42 exposed to the outside. Then, in the jet nozzle body 52, a cleaning liquid 51 to which ultrasonic vibration is applied upward from the front end (upper end) is ejected. That is, the ultrasonic cleaning nozzle 5 is installed so as to spray the cleaning liquid 51 toward the grinding surface 42a of the grinding stone 42 rotating in order to grind the workpiece W.

Here, the specification of the ultrasonic cleaning nozzle 5 in the present embodiment is as follows.

Vibration frequency of the ultrasonic vibrator 55: 450 kHz to 1.0 MHz

The output of the power supply means 56: 40 to 100 W

The nozzle flow rate of the cleaning liquid 51 from the spray nozzle body 52: 1000 to 1500 cc / min

The ultrasonic vibration imparted by the ultrasonic vibrator 55 in the cleaning liquid 51 sprayed from the ultrasonic cleaning nozzle 5 can be absorbed in a predetermined range of the spray direction of the cleaning liquid 51 Mm). The position of the ultrasonic cleaning nozzle 5 in the vertical direction is set so that the grinding surface 42a of the grinding stone 42 is positioned in the intermediate region of the predetermined range. Accordingly, during grinding, the grinding surface 42a is lowered The grinding surface 42a is continuously cleaned by the cleaning liquid 51. As shown in FIG.

Next, a grinding method using the grinding apparatus 1 of the present embodiment will be described. First, the workpiece W is transferred to the holding table 3 by the transfer means (not shown), and the workpiece W is sucked and held on the holding surface 3a of the holding table 3. Next, the holding table 3 is continuously rotated by the rotating means 31, and the spindle 43 is driven to rotate the grinding wheel 41. The grinding means 4 is moved to the upper side of the holding table 3 and the left end side of the grinding stone 42 is positioned on the center of the work W and the grinding stone 4 42 are projected from the holding table 3 to the right. The grinding means 4 is lowered at a predetermined feeding speed while the rotation of the holding table 3 and the grinding wheel 41 is continued. The cleaning liquid 51 is ejected toward the grinding surface 42a by the ultrasonic cleaning nozzle 5 when the grinding stone 42 reaches the position immediately before the abrasive wheel 42 contacts the workpiece W. [ The cleaning liquid 51 is subjected to ultrasonic vibration at a vibration frequency of 450 kHz to 1.0 MHz by the ultrasonic vibrator 55.

The grinding wheel 4 is brought into contact with the workpiece W by the descent of the grinding means 4 while the holding table 3 and the grinding wheel 41 are rotating, 4). Even during this grinding, the spraying of the cleaning liquid 51 from the ultrasonic cleaning nozzle 5 is continuously performed on the grinding surface 42a exposed to the outside. The grinding surface 42a of the grinding stone 42 is cleaned and dressed by the jetting of the cleaning liquid 51 at the same time as the grinding and the attachment of the grinding surface 42a can be efficiently removed, The grinding quality can be improved.

As described above, according to the present embodiment, since the grinding wheel 41 is sprayed with the cleaning liquid 51 imparted with ultrasonic waves to dress the grinding surface 42a, it is possible to eliminate the dress by the dressing board. Thus, it is possible to eliminate the cost and management burden of preparing a large number of dressing boards. In addition, it is possible to omit the operation of interrupting the grinding and replacing the dressing board, and the grinding efficiency can be improved by increasing the continuity of grinding.

Next, an experiment conducted to confirm the grinding quality improvement effect in the grinding apparatus according to the above embodiment will be described. In this experiment, in Examples 1 to 3 and Comparative Examples 1 to 4, grinding was carried out to reduce the thickness of the workpiece W from 250 m to 200 m, and the workpiece W was cut into a disk-shaped borosilicate glass 300 mm). In Examples 1 to 3 and Comparative Examples 1 to 4, with the same grinding apparatus 1 as in the above-described embodiment except that the frequencies of the ultrasonic waves applied to the cleaning liquid 51 were set to be different from each other, And the grinding was performed. The frequencies of Examples 1 to 3 and Comparative Examples 1 to 4 were 450 kHz, 750 kHz, 1.0 MHz, no ultrasonic waves (0 Hz), 300 kHz, 1.5 MHz, and 3.0 MHz, respectively. In Examples 1 to 3 and Comparative Examples 1 to 4, the following conditions were set the same.

Type of grinding wheel (42): Vitrified system # 1000

The number of revolutions of the spindle 43: 1500 rpm

Rotation speed of the holding table 3: 140 rpm

Vertical feed rate of grinding wheel 41: 0.3 占 퐉 / sec

Flow rate of the ultrasonic cleaning nozzle 5: 1200 cc / min

Output of ultrasonic cleaning nozzle 5: 50 W

In Examples 1 to 3 and Comparative Examples 1 to 4, the amount of consumption of the grinding wheel 42 was measured after the workpiece W was ground. The measurement results are shown in Fig. Further, after grinding in Examples 1 to 3 and Comparative Examples 1 to 4, the quality of each workpiece W on the ground surface to be polished was confirmed. The results of confirmation of the grinding quality are shown in Table 1 below. In Table 1, "? &Quot; of the grinding quality indicates that both the surface roughness and the saw mark of the surface to be ground of the workpiece W are in a very good state and the product precision using the workpiece W is excellent . The surface roughness of the surface to be ground and the cutting marks of the workpiece W are both in a good state and the product precision using the workpiece W is excellent. Indicates that the surface quality of the workpiece W is insufficient and the surface roughness and cutting marks of the workpiece W are insufficient and that the accuracy of the workpiece W is sufficient There is a case that can not be done.

Frequency [Hz] Grinding quality Example 1 450k ◎ Example 2 750k ◎ Example 3 1.0M ○ Comparative Example 1 No ultrasonic waves △ Comparative Example 2 300k △ Comparative Example 3 1.5M △ Comparative Example 4 3.0M △

From the results shown in Fig. 1, the consumption amounts of the grinding wheel 42 are reduced in Examples 1 to 3, in which the frequency is 450 kHz to 1.0 MHz, as compared with Comparative Examples 1 to 4, It can be understood that the excessive consumption due to the collapse is improved. Such an improvement effect is obtained by changing the frequency of the ultrasonic cleaning nozzle 5 while changing the frequency so that the amplitude of the ultrasonic wave in the cleaning liquid 51 also changes and both conditions of the amplitude and the frequency become appropriate values I guess. By reducing the consumption amount of the grinding stone 42 as in the first to third embodiments, it is possible to extend the service life of the grinding stone 42 and to prolong the period for exchanging the grinding stone 42, It is possible to improve the grinding efficiency by increasing the continuity.

From the results shown in Table 1, it can be understood that the grinding quality is improved in both the surface roughness and the cutting edge in the range of 450 k to 1.0 MHz, particularly 450 k to 750 kHz with respect to the grinding quality. This tendency is attributed to a decrease in the hole collapse and consumption of the grinding wheel 42 in the above frequency range, an increase in the grinding amount of the workpiece W, an increase in grinding efficiency, and an improvement in the finishing accuracy of the grinding surface do.

Further, the present invention is not limited to the above-described embodiment, and various modifications can be made. In the above-described embodiment, the size, shape and the like shown in the accompanying drawings are not limited to this, and it is possible to appropriately change them within the range of exerting the effect of the present invention. It is to be understood that the present invention is not limited to these embodiments, and various modifications may be made without departing from the scope of the present invention.

 For example, in the ultrasonic cleaning nozzle 5, the mounting position of the ultrasonic transducer 55 is set in a pipe for supplying the cleaning liquid 51 on the outside of the injection nozzle body 52, It is possible.

INDUSTRIAL APPLICABILITY As described above, the present invention has an effect of preventing a large amount of consumable products from being generated by grinding, and is particularly useful for a grinding method in which grinding is performed continuously.

1: Grinding device
3: retention table
4: Grinding means
41: grinding wheel
42: Grinding stone
42a: Grinding surface
5: Ultrasonic cleaning nozzle
51: Cleaning liquid
52: injection nozzle body
53:
55: ultrasonic vibrator
56: power supply means
W: Workpiece

Claims (1)

1. A grinding apparatus comprising grinding means provided with a grinding wheel for grinding a workpiece held by the grinding table,
An ultrasonic vibrator for applying an ultrasonic wave to the cleaning liquid supplied from the cleaning liquid supply unit; and an ultrasonic vibrator for applying AC power to the ultrasonic vibrator, wherein the cleaning liquid is supplied from the cleaning liquid supply unit to the spray nozzle body, And an ultrasonic cleaning nozzle constituted by a power supply means for supplying ultrasonic waves,
Wherein the ultrasonic cleaning nozzle is arranged to spray a cleaning liquid to which an ultrasonic wave is applied toward a grinding surface of a grinding wheel of the grinding wheel grinding the workpiece,
Wherein a vibration frequency of the ultrasonic vibrator is set to 450 kHz to 1.0 MHz.

Images