JP4936443B2 - Liquid honing method - Google Patents

Description

  The present invention relates to a liquid honing method (hereinafter also referred to as “processing method”), and more particularly, to a liquid honing method for a workpiece that is not subject to contamination.

  Conventionally, processing by liquid honing has been used for the purpose of polishing or finishing the surface of a workpiece. Liquid honing is a processing method in which surface processing is performed by spraying a honing liquid containing abrasive grains on a processing surface of a workpiece.

In general, when there is a portion that is not desired to be processed in liquid honing, as shown in FIG. 2 (a), the surface of the workpiece 20 is covered with a mask member such as a tape 21 that is bonded via an adhesive 22. The spraying process is performed with the portion masked (for example, Patent Document 1). Thereby, since the honing liquid 10 containing the abrasive grains does not come into contact with the masked portion, as shown in FIG. The unprocessed region B can be left as it is.
JP-A-11-004063 (Claims etc.)

  However, when a liquid honing process is performed on a workpiece that does not like contamination such as a silicon wafer, if the masking is performed with an adhesive tape, the adhesive may remain on the masked portion. The adhesive is problematic because it cannot be easily removed by washing with water or the like.

  Accordingly, an object of the present invention is to perform processing on a workpiece that is not subject to contamination, such as a silicon wafer, without causing a problem of residual adhesive due to a mask and in a state in which a non-processed area is reliably protected. It is to provide a liquid honing method that can be used.

  As a result of intensive studies, the present inventor has found that the above-described problem can be solved by adopting the following configuration, and has completed the present invention.

  That is, the liquid honing method of the present invention is a liquid honing method for processing a surface of a workpiece by spraying a honing liquid containing abrasive grains onto the surface of the workpiece. In providing the processing region, the non-processing region is covered with a mask member that is not in contact with the workpiece surface, and the honing liquid is filled with a liquid between the mask member and the workpiece surface. It is characterized by spraying.

  In the present invention, the liquid is preferably supplied between the mask member and the workpiece surface via the mask member, and more preferably, the honing is continued while supplying the liquid. Spray the liquid. In this case, the distance between the mask member and the workpiece surface is preferably 0.1 to 3.0 mm. Moreover, as the liquid, pure water can be suitably used. The present invention is particularly effective when the workpiece is a silicon wafer.

  According to the present invention, with the above-described configuration, a non-working region is reliably protected without causing a problem of residual adhesive due to a mask even on a workpiece that is not suitable for contamination such as a silicon wafer. It has become possible to realize a liquid honing processing method that can be processed by the above method.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows an embodiment of the liquid honing method of the present invention. As shown in the figure, in the present invention, the surface of the workpiece 20 is processed by spraying a honing liquid 10 containing abrasive grains onto the surface of the workpiece 20. Reference numeral 11 in the figure denotes a nozzle of a honing liquid spray gun.

  In the present invention, when the non-processed region X is provided on the surface of the workpiece 20, the non-processed region X is covered with the mask member 1 that is not in contact with the workpiece surface, and the mask member 1 and the workpiece. It is important that the honing liquid is sprayed in a state where the liquid 2 is filled with the surface. In the present invention, the mask member 1 that covers the non-processed region X on the workpiece surface is disposed with a slight gap between the workpiece surface and directly contacts the workpiece surface like a conventional adhesive tape. As a result, there is no problem of adhesive residue. Further, when the gap is simply opened, the honing liquid 10 may enter the gap and the surface of the non-processed region X may be damaged by abrasive grains. In the present invention, the gap 2 is filled with the liquid 2. Therefore, it is possible to prevent this.

  For example, the liquid 2 can be supplied between the mask member 1 and the surface of the workpiece via the mask member 1, and in particular, the honing liquid 10 is sprayed while the liquid 2 is continuously supplied. Thereby, even when abrasive grains enter between the mask member 1 and the workpiece surface, the entered abrasive grains are decelerated by the pressure of the liquid 2 and pushed back, so that they do not stay on the workpiece surface. The masking function can be exhibited more reliably. The material of the mask member 1 is not particularly limited, but the upper surface is made of a material having a hardness equal to or higher than that of the abrasive grains in the honing liquid 10 (SiC or other ceramics, or DLC (Diamond Like). Carbon)) or a soft material (rubber) that absorbs the impact of the honing liquid 10, and the lower surface may come into contact with the workpiece 20 unexpectedly, such as nylon. However, it is possible to use a pad formed of a material that is not damaged and does not cause metal contamination.

  As a method of supplying the liquid via the mask member 1, for example, a pipe 3 for introducing the liquid into the central portion of the mask member 1 may be provided as illustrated. The supplied liquid 2 is discharged to the outside of the non-working region X through a gap between the mask member 1 and the workpiece surface as shown in the figure. In this case, when the supply pressure of the liquid 2 is high, the honing liquid 10 is repelled and the effect of the liquid honing is reduced. Therefore, it is preferable that the supply pressure is not increased too much. The discharge pressure of the air that ejects the liquid 2 can be about 0.3 MPa.

  Moreover, the distance between the mask member 1 and the workpiece surface is preferably 0.1 to 3.0 mm. By setting the distance of the gap between the mask member 1 and the workpiece surface within the above range, the gap can be filled with the liquid 2 due to the surface tension of the liquid 2. Any liquid 2 may be used as long as it does not adversely affect the workpiece 20, but pure water is preferably used.

  In the present invention, as described above, the mask member 1 and the liquid 2 are not particularly limited except that the non-processed region is protected while the non-processed region is protected. be able to. The processing may be performed by determining the size / shape of the mask member 1 and the required flow rate according to the size of the workpiece and the size / shape of the processing region. The present invention is particularly useful when processing the surface of a workpiece 20 that is not subject to contamination, such as a silicon wafer, by liquid honing.

  For example, as a kind of abrasive grain used when processing a silicon wafer, SiC etc. can be mentioned, and the grain size of an abrasive grain is 0.25-10.0 micrometers suitably, especially 0.25-3. 0 μm. Moreover, as a liquid which mixes an abrasive grain, water can be used, for example. Moreover, the density | concentration of the abrasive grain mixed with the honing liquid 10 can be 5 to 40%.

  Furthermore, in order to implement surface processing efficiently, the pressure of the compressed air when spraying the honing liquid 10 onto the silicon wafer surface can be set to 0.05 to 3.0 MPa, for example. Furthermore, the distance between the spray nozzle and the silicon wafer surface is, for example, 0.5 to 100 mm.

  In addition, after the surface treatment by liquid honing, in order to prevent impurities such as abrasive grains from remaining on the surface of the workpiece 20, the surface is preferably washed with water or the like. Specifically, for example, after performing spin cleaning in which pure water is dripped at 1 liter / min from the center while rotating the workpiece at 500 rpm, nitrogen with a discharge pressure of about 0.1 MPa is similarly applied from the center of the workpiece. Spin dry by blowing gas.

Hereinafter, the present invention will be described in more detail with reference to examples.
(Example)
A 300 mm silicon wafer having a nitride film with a thickness of 0.2 μm on the surface is subjected to a honing liquid containing abrasive grains having a concentration of 17% and a particle diameter of 2 μm in water using a spray nozzle, an air pressure of 0.3 MPa, and a flow rate. The liquid honing process was performed by spraying at 6 liter / min. At this time, as shown in FIG. 1, the non-processed region X is covered with a pad (material: SiC (upper surface), NC nylon (lower surface)) as a mask member 1 that is not in contact with the silicon wafer surface, and liquid honing is performed. During the treatment, pure water 2 was supplied between the mask member 1 and the workpiece surface via the pipe 3 and the mask member 1. The flow rate of pure water 2 was 0.5 liter / min, and the distance between the mask member 1 and the workpiece (silicon wafer) was 0.5 mm. The distance between the nozzle and the workpiece (silicon wafer) was 40 mm. Furthermore, the processing time was 5 minutes.

  When the non-processed area | region X was confirmed after the process, there was no damage by an abrasive grain in this area | region, As a result, only the area | region which should be processed was processed. That is, even if there is a gap between the mask member 1 and the workpiece surface, the pure water is discharged while filling the gap with pure water, so that the honing liquid 10 is in the center of the non-working region. As a result, it was confirmed that the masking function was sufficiently exerted by the mask member 1 and the pure water 2.

It is a schematic explanatory drawing which shows one Embodiment of the liquid honing processing method of this invention. It is a schematic explanatory drawing which shows the conventional liquid honing process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mask member 2 Liquid 3 Piping 10 Honing liquid 11 Spray nozzle 20 Work piece 21 Mask tape 22 Adhesive A Processing area B, X Non-processing area

Claims (6)

In a liquid honing method for processing the workpiece surface by spraying a honing liquid containing abrasive grains on the surface of the workpiece,
In providing a non-working region on the workpiece surface, the non-working region is covered with a mask member that is not in contact with the workpiece surface, and a liquid is filled between the mask member and the workpiece surface. A liquid honing method, wherein the honing liquid is sprayed in a state.   The liquid honing method according to claim 1, wherein the liquid is supplied between the mask member and the workpiece surface through the mask member.   The liquid honing processing method according to claim 2, wherein the honing liquid is sprayed while the liquid is continuously supplied.   The liquid honing method according to claim 1, wherein a distance between the mask member and the workpiece surface is 0.1 to 3.0 mm.   The liquid honing method according to claim 1, wherein pure water is used as the liquid.   The liquid honing method according to claim 1, wherein the workpiece is a silicon wafer.

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