JPH06238559A - Single-sided surface polishing - Google Patents

Abstract

PURPOSE:To prevent the generation of faults on the surface of a substrate due to the abrasion chip by forming a recess on the edge surface of a carrier and attaching a soft cloth on the part ranging from the recessed part to the carrier side surface part, in the polishing for a workpiece which is inserted through a cloth into a carrier. CONSTITUTION:As for the single-sided surface polishing in which a carrier having a hole for accommodating a workpiece is installed on a pressure plate, and polishing work is carried out, supplying the polishing liquid in which the polishing material such as cerium cxide is suspended in water. A recess is formed on the carrier, in a certain depth, e.g. 0.5-1.5mm along the carrier surface from the carrier edge surface part where the carrier and the workpiece contact. A soft cloth is attached on the part ranging from the recessed part to the carrier side surface part. The recess has a width (5mm or more) from the carrier side surface in contact with a base plate to the outer periphery, and the depth is set larger than the thicknes of the soft cloth. As the soft cloth, is used the foamed polyurethane nonwoven fabric.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention eliminates the occurrence of cracks, cracks, scratches and the like on the one-sided polishing method, particularly on the end face of a glass substrate and prevents the adhesion of the polishing material to the end face of the workpiece. It relates to a single-sided polishing method.

[0002]

2. Description of the Related Art In the conventional one-sided polishing method, a carrier having a hole for accommodating the work piece is attached to a work piece, and a polishing material such as cerium oxide is suspended in water. It is performed by applying polishing liquid while applying polishing liquid, but when defect-free and high precision is required, such as for large LCD mask substrates, a soft cloth is attached to the pressure plate side. A method has also been proposed (see Japanese Patent Application No. 3-317539).

However, when the work piece is a rectangular substrate made of a brittle material such as glass, there is a drawback that defects such as cracks, breaks and scratches are very likely to occur on the outer peripheral portion of the substrate. However, this also has the disadvantage that the glass chips and abrasion debris of the carrier generated at this time also damage the substrate surface, but this is because the direction of the force that the substrate receives during polishing changes the substrate. It is caused by trying to move to a stable position in the carrier.

In the case of one-side polishing of a square substrate, the carrier is rotating as shown in FIG. 3, so that the direction of the force received by the substrate in the carrier changes at a substantially constant angular velocity as shown in FIG. Therefore, as shown in FIG. 4, the movement of the substrate in the carrier causes the substrate to move in different directions in the carrier each time the force received by the substrate changes, and collides with the side surface of the carrier. As a result, defects such as cracks occur on the end face of the substrate, glass fragments are emitted from the substrate, and carrier abrasion debris is emitted.

Even if no cracks, cracks, scratches, or other defects occur, the substrate and the carrier collide with each other with a considerable force, so that the abrasive is pressed into the fine irregularities on the end face of the substrate. Due to the phenomenon
When the substrate after polishing is cleaned, the abrasive material pushed in is gradually released, which requires a considerable time for cleaning the substrate, and it is difficult to finish the substrate cleanly. For this reason, conventionally, the clearance between the carrier and the substrate is made as small as possible to shorten the time for which the substrate receives a force, and the impact force when the substrate collides with the carrier is minimized. It is also practiced to process the end surface of the substrate into a mirror surface in order to provide impact resistance.

[0006]

However, even if the machining accuracy of the carrier is improved and the clearance between the carrier and the substrate is minimized, the occurrence of surface defects due to cracks, cracks, scratches and carrier abrasion debris is completely eliminated. It is difficult to prevent the abrasive material from being pushed into the edge of the substrate, and even if the edge of the substrate is made to be a mirror surface, the occurrence of surface defects due to cracks, cracks, scratches and carrier abrasion debris is less frequent. Just to reduce
This cannot be completely suppressed.

[0007] Further, even if the end surface of the substrate is made to be a mirror surface and the method of minimizing the clearance between the carrier and the substrate is used together, a scratch is generated between the carrier and the substrate, and an abrasive material is attached to the scratch. It may be pushed in, cracks may occur from the scratched part, carrier wear debris may not be generated, and basic processing,
Particularly in cleaning, when handling by hand, the substrate whose end surface is processed into a mirror surface is very slippery, which poses another problem that it is dangerous, and it takes a considerable time to make the substrate end surface into a mirror surface. However, there is a disadvantage that it becomes economically disadvantageous.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a one-sided wear method which solves the above disadvantages and drawbacks.
This is a one-sided polishing method in which cloth is attached to the carrier attached to the pressure plate, and then the workpiece is put into the carrier for polishing. The carrier is provided with a soft cloth attached to the side surface of the carrier from the recessed portion.

That is, the inventors of the present invention have conducted various studies to develop a single-sided polishing method that eliminates the occurrence of defects such as cracks, cracks, scratches and surface defects on the end surface of the substrate, and as a result, carriers attached to the pressure plate have been investigated. With the cloth stuck inside, a recess with a certain depth is provided along the carrier surface from the carrier end surface, and when using a carrier with a soft cloth stuck to the carrier side surface from this recess, the cracks and cracks generated on the substrate end surface It has been found that defects such as, for example, can be eliminated, and that defects do not occur on the substrate surface even if abrasion debris occurs, and the types of soft cloth used here, the depth of the dents, and the carrier The present invention has been completed by conducting research on the clearance between the workpiece and the workpiece. This will be described in more detail below.

[0010]

The present invention relates to a one-sided polishing method, which is used for applying one-sided polishing to a carrier attached to a pressure plate by carrying out one-side polishing from the end surface of the carrier where the carrier and the workpiece come into contact with each other. It is characterized by using a carrier with a recess of a certain depth and sticking a soft cloth to the side surface of the carrier on this recessed part. It is possible to completely eliminate the occurrence of defects and to prevent the occurrence of defects on the substrate surface due to abrasion debris.

According to the above-mentioned proposal, the single-sided polishing method of the present invention firstly attaches a carrier having a hole larger than the substrate size to a pressure plate and attaches a cloth to the top plate of the carrier. Since it is preferable to use a suede type having an elastic modulus of 3 to 80% and a foam layer, it may be made of a polyurethane non-woven fabric, but this may be stretched in a carrier. , May be stretched on the work piece.

Since the carrier used here is not soaked with water, it may be generally made of vinyl chloride resin, which is the end face of the carrier with which the carrier and the workpiece are in contact. A concave portion having a certain depth, for example, a depth of 0.5 to 1.5 mm, is provided along the surface of the carrier from the portion, and a soft cloth is attached from the concave portion to the side surface of the carrier. As shown in FIG. 1, this recess has a certain width from the side surface of the carrier in contact with the substrate to the outer periphery. If this width is 5 mm or less, the probability of peeling of the cloth during polishing is high and stable polishing is achieved. Therefore, the thickness is preferably 5 mm or more, more preferably 10 mm or more.

Further, this carrier is provided with a hole for adhering the cloth, and it is necessary that the size of the hole is such that an appropriate gap is formed when the substrate on which the cloth is adhered is put. . However, if this gap is less than 1 mm, the end surface of the substrate after polishing will not be a semi-mirror surface, and the effect of cleaning will be halved. If it is more than 4 mm, the wear of the cloth on the end surface of the carrier will be severe. In an extreme case, the cloth disappears and contact with the carrier occurs, and cracks occur at the end face of the substrate. Therefore, it is preferable to set this to 1 mm to 4 mm.

Further, according to the present invention, a carrier is used in which the cloth is adhered from the recessed portion to the side surface of the carrier. When the cloth is adhered, the cloth is easily peeled off during polishing if the cloth is projected from the carrier. So it should not stick out of the carrier. The fabric is water resistant and needs to be a soft fabric to prevent scratches on the substrate surface from abrasion debris.
The cloth is preferably made of the same quality as the above-mentioned non-woven polyurethane foam used for polishing, but this cloth is attached to the end of the carrier rather than the recessed portion in order to prevent the cloth from peeling. It is good to put it on your body and become one.

[0015]

EXAMPLES Examples and comparative examples of the present invention will be given below. Example 1 An Oscar type single-side polishing machine [made by Lapmaster Co., Ltd.] was used, and a 402 mm square hole was made in the center of a vinyl chloride resin plate having a diameter of 600 mmφ as this carrier, and 10 mm was formed around this hole. A dent with a width of 0.6 mm is made, and cloth NF-20 is placed on the top plate side to prevent scratches on the substrate surface.
0 [Rodel Nitta Co., Ltd.] is cut to 402mm and attached, and the thickness is further extended from the recess to the end face of the carrier.
0.5mm urethane foam cloth / 40 film [Roder Nitta
Manufactured by K.K.] was used.

Then, using this single-sided polishing machine, 400 mm square × 6
A synthetic quartz glass substrate with a thickness of mm, the end surface of which was finished with free abrasive grains GC # 800, was prepared by using an abrasive material prepared by suspending 10% of cerium oxide abrasive material with an average particle diameter of 1 μm in water. The front side and the back side were alternately alternated for 30 minutes, and this was repeated 6 times for polishing.

In this experiment, five substrates were processed under the above-mentioned conditions and then cleaned using an ultrasonic cleaning tank of 10 tanks. When the surface defects and stains were visually inspected under an illuminance of 120,000 lux, the results shown in Table 1 below were obtained.

Example 2 A substrate obtained by processing in the same manner as in Example 1 except that the hole size of the carrier in Example 1 was 405 mm was inspected and the results shown in Table 1 below were obtained. Was obtained.

Example 3 A substrate obtained by the same treatment as in Example 1 was inspected except that the number of ultrasonic cleaning baths in Example 1 was changed from 10 to 5, and the results are shown in Table 1 below. The following results were obtained.

Comparative Example 1 A substrate obtained by treating in the same manner as in Example 1 except that a soft cloth was not attached to the carrier in Example 1 was inspected, and the results shown in Table 1 below were obtained. Was given.

Comparative Example 2 A substrate obtained by processing in the same manner as in Comparative Example 1 described above except that the end surface portion of the substrate in Comparative Example 1 was mirror-finished was inspected, and the results are shown in Table 1 below. The following results were obtained.

COMPARATIVE EXAMPLE 3 Except that the end surface portion of the substrate in Example 1 was mirror-finished, the hole size of the carrier was 400.5 mm, and no soft cloth was attached to the carrier. When a substrate obtained by treating in the same manner as the example was inspected, the results shown in Table 1 below were obtained.

Comparative Examples 4 to 5 Obtained by treating in the same manner as in Example 1 except that the hole size of the carrier in Example 1 is 406 mm (Comparative Example 4) or 401.5 mm (Comparative Example 5). When the obtained substrate was inspected, the results shown in Table 1 below were obtained.

Comparative Examples 6 to 7 Similar to Example 1 except that the width of the recess of the carrier in Example 1 is set to 5 mm (Comparative Example 6) or the depth of the recess is set to 0.30 mm (Comparative Example 7). When the processed substrate was inspected, the results shown in Table 1 below were obtained.

Substrates obtained by the same treatment as in Example 1 were examined except that the soft cloth used in Example 1 was a normal woven cloth (cotton), and the results are shown in Table 1 below. The following results were obtained.

[0026]

[Table 1]

[0027]

INDUSTRIAL APPLICABILITY The present invention relates to a single-sided polishing method in which a cloth is attached to a carrier attached to a pressure plate as described above, and then a work piece is put in to perform polishing. Characterized by using a carrier in which a recess having a certain depth is provided along the carrier surface from the end face of the carrier where the carrier and the workpiece come into contact, and a soft cloth is attached to the side face of the carrier from the recessed part. According to this, it is possible to prevent the occurrence of cracks, breaks, scratches, etc. at the end surface of the object to be processed, and to prevent the adhesion of the abrasive to the end surface of the object to be processed. .

[Brief description of drawings]

FIG. 1A is a plan view of a recess formed on the surface of a carrier used in the present invention, and FIG. 1B is a partial cross-sectional view thereof.

2A and 2B are configuration diagrams of a carrier used in Embodiment 1 of the present invention, in which FIG. 2A is a plan view thereof, and FIG.

FIG. 3 is a plan view showing changes in angular velocity due to rotation of a top plate in known single-sided polishing.

FIG. 4 is a plan view showing movement of a rectangular substrate in a carrier in known single-sided polishing.

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[Procedure amendment]

[Submission date] November 9, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

[1] shows a plan view and a partial cross-sectional view of the shape states of the recess formed is provided on the carrier surface to be used in the present invention.

FIG. 2 Shape of carrier used in Example 1 of the present invention
It is the top view of a state and the partial sectional view of the dent.

FIG. 3 is a plan view showing changes in angular velocity due to rotation of a top plate in known single-sided polishing.

FIG. 4 is a plan view showing movement of a rectangular substrate in a carrier in known single-sided polishing.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masatoshi Takita 28, Nishi-Fukushima, Kubiki-mura, Nakakubiki-gun, Niigata Prefecture 1 Shin-Etsu Chemical Co., Ltd.

Claims (5)

[Claims] 1. A one-sided polishing method in which a cloth is attached to a carrier attached to a pressure plate, and then a workpiece is put into the carrier for polishing. A single-sided polishing method comprising using a carrier having a recess having a constant depth and having a soft cloth attached to the side surface of the carrier from the recess. 2. The single-sided polishing method according to claim 1, wherein the soft cloth is a foamed polyurethane non-woven fabric. 3. The single-sided polishing method according to claim 1, wherein the work piece is glass. 4. The single-sided polishing method according to claim 4, wherein the depth of the depression is larger than the thickness of the soft cloth. 5. The clearance between the carrier and the workpiece is 1
The single-sided polishing method according to claim 1, which is not less than 4 mm and not more than mm.