JP3170134U - Magnet strainer and polishing apparatus using the same - Google Patents

Abstract

To provide a magnet strainer capable of easily confirming foreign matter adhering to a magnet in a magnet strainer for use in a substrate polishing apparatus, and a polishing apparatus using the same.
When polishing a glass substrate with a polishing machine using polishing slurry supplied and circulated from a polishing slurry tank, a magnet strainer is provided in the polishing slurry circulation path. The magnet strainer has a viewing window 9 through which the inserted magnet 10 can be confirmed. Alternatively, the magnet strainer has a transparent container. Therefore, the metal foreign matter adhering to the magnet can be easily confirmed.
[Selection] Figure 1

Description

  The present invention relates to a magnetic strainer used for a working fluid (coolant) used in a polishing apparatus for polishing a flat substrate such as a magnetic disk substrate and a magnetic disk, and a polishing apparatus using the same.

  For manufacturing semiconductor devices and liquid crystal screens, polishing of glass, quartz, and silicon wafers, which are the materials, is an important technology. In particular, a technique for polishing a glass substrate made of quartz glass is widely used industrially including the manufacture of magnetic disk devices. In the polishing of quartz glass, a polishing pad is applied to the surface of the glass substrate, and polishing is performed while rubbing the surface of the glass substrate with the polishing pad while supplying a polishing slurry containing a cerium oxide abrasive between the polishing pad and the substrate. ing. The polishing slurry is a polishing liquid containing abrasive grains.

  As described above, when polishing with the polishing slurry, scratches may occur on the surface of the glass substrate due to foreign matter contained therein, foreign matter attached to the glass surface, or foreign matter peeled off from the glass surface. A method using a magnetic strainer has been proposed to remove magnetic foreign substances in the polishing slurry. For example, Patent Document 1 discloses a method for manufacturing a magnetic disk substrate for polishing a magnetic disk substrate. According to this method, a polishing slurry is circulated between a polishing apparatus and a polishing slurry tank in a circulation path. A magnet strainer is installed.

  The magnet strainer is a stainless steel metal tube with a magnet installed inside. When the polishing slurry passes through the magnet strainer, the metal foreign matter in the polishing slurry adheres to the magnet and is removed. This strainer device with a magnet is also disclosed in Patent Document 2.

JP 2006-099944 A Utility model registration No. 3002527

  However, these magnet strainers are basically sealed containers made of stainless steel or the like, and it is difficult to visually confirm the degree of adhesion of metal foreign matter to the magnets. It is necessary for the operator to check the situation where metal foreign objects are attached to the magnet and to open the metal pipe periodically to clean it if metal foreign objects etc. are attached and dirty. . For this reason, there is a need for a technique that allows easy confirmation of foreign matter adhering to the magnet in the magnet strainer and easy cleaning.

The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide a magnet strainer in which foreign matter adhering to a magnet in a magnet strainer can be easily confirmed and can be easily cleaned, and a polishing apparatus using the magnet strainer.

In order to achieve the above object, the present invention takes the following means.
The present invention provides a magnet strainer used in a polishing apparatus for polishing a surface to be polished using a polishing slurry, and a polishing apparatus using the same.

  The magnetic strainer of the present invention is a container for allowing polishing slurry to pass, and is made of a transparent material. The magnetic strainer container is provided with a viewing window for visually checking the internal situation from the outside. It is for adsorbing the magnetic metal contained in the polishing slurry when passing through the inside, and is characterized by comprising a magnet inserted in a magnet strainer container. The viewing window is installed in the vicinity of the water inlet of the magnet strainer container for introducing the polishing slurry into the magnet strainer container.

  The magnet strainer of the present invention is a container for passing polishing slurry, and is included in the polishing slurry when the polishing slurry flows through the inside of the magnet strainer container. It is for adsorbing a magnetic metal and is characterized by comprising a magnet inserted in a magnet strainer container.

The magnetic strainer of the present invention further has the following features.
In order to clean the iron powder, the magnet of the above-described magnet strainer is preferably attached with a magnetic material removal ring or a scraper made of a cylindrical nonmagnetic material. Also, the magnet is arranged in the tube by arranging magnet elements, which are permanent magnets, and spacers, which are magnetic bodies, alternately in the axial direction of the tube, and arranged so that the same poles of the magnet elements are opposed and repelled. It is good that it is. Further, the magnet has a holder, and the outer peripheral surface of the holder is preferably formed with knurled irregularities so that the operator can easily grip it. The surface to be polished is preferably a glass or quartz substrate. The polishing slurry is preferably a cerium oxide slurry.

  A polishing apparatus of the present invention includes the above-described magnet strainer, a polishing slurry tank for temporarily storing polishing slurry, a polishing machine for polishing a surface to be polished using the polishing slurry, a polishing slurry tank, and a magnetic strainer. Between the magnetic strainer and the polishing machine, and between the polishing machine and the polishing slurry tank, and a pipe for transporting the polishing slurry, and a closed circulation path consisting of the polishing slurry tank, the magnet strainer, the polishing machine, and the pipe. The polishing slurry is circulated.

  According to the magnet strainer of the present invention and the polishing apparatus using the same, the following effects can be obtained. When a transparent viewing window is installed in the magnet strainer container or a transparent material is used for the magnet strainer container, it is possible to easily check for metal foreign objects adhering to the magnet in the container. Can now be easily determined.

FIG. 1 is a schematic view illustrating a magnet strainer according to a first embodiment of the present invention. FIG. 2 is a schematic view illustrating a magnet of the magnet strainer according to the first embodiment of the present invention. FIG. 3 is a conceptual diagram showing an outline of the polishing apparatus according to the embodiment of the present invention.

  A first embodiment of a magnet strainer 1 of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing the appearance of the magnet strainer 1. FIG. 2 is a front view showing the magnet strainer 3 of the magnet strainer 1. The magnet strainer 1 includes a magnet strainer container 2 and a magnet strainer 3 accommodated in the magnet strainer container 2. The magnet strainer container 2 is an elongated cylindrical container having a hollow inside. One upper end (on the drawing) of the magnet strainer container 2 is open.

  As shown in FIG. 1, a ferrule 5 is connected to the upper opening of the magnet strainer container 2. The ferrule 5 is a joint for piping, and the ferrule 13 attached to the magnet strainer 3 is for fixing with a clamp 15 (details will be described later). The lower end of one of the magnet strainer containers 2, that is, the lower part of the magnet strainer container 2 in FIG. The drainer 6 includes a female screw 6a welded to the bottom of the magnet strainer container 2 and a hexagon socket plug 6b fitted to the female screw 6a.

  A hexagonal wrench is inserted into the hexagonal hole and turned to remove the hexagonal socket plug 6b. Thereby, the foreign substance in the magnet strainer container 2 is taken out from the hole of the female screw 6a, and liquid such as polishing slurry is discharged. The magnet strainer container 2 passes through the polishing slurry, and the polishing slurry discharged therefrom is supplied to the polishing machine. For this purpose, the magnet strainer container 2 has a water inlet 7 for receiving the polishing slurry in the magnet strainer container 2 and a water outlet 8 for discharging the polishing slurry in the magnet strainer container 2.

  In the figure, the water inlet 7 is installed at the bottom of the magnet strainer container 2, and the water outlet 8 is installed at the top of the magnet strainer container 2. The water inlet 7 and the water outlet 8 are installed in the magnet strainer container 2 by arbitrary fixing means. For example, the water inlet 7 and the water outlet 8 may be welded to the magnet strainer container 2. The magnet strainer container 2 has a viewing window 9 so that the inside can be viewed from the outside. In the example of FIG. 1, the observation window 9 is installed in the lower part of the magnet strainer container 2 and in the vicinity of the water inlet 7. The magnet strainer container 2 can be made of any known material.

  Considering the ease of connection with a general-purpose stainless steel ferrule, the magnet strainer container 2 is preferably made of stainless steel. Since the magnet strainer container 2 is made of an opaque material, a viewing window 9 is provided to confirm the state therein. The viewing window 9 has a structure in which a hole formed in the magnet strainer container 2 is closed with a transparent material lid. Basically, the transparent material of the lid is preferably transparent to visible light, but can also be transparent to some frequencies of visible light.

  Any known material can be used as long as the metal or the like attached to the magnet in the magnet strainer container 2 can be visually observed. For example, as such a material, glass, transparent acrylic resin, polycarbonate resin (PC), polyphenylene sulfide (PPS), polybutylene terephthalate resin (PBT), or the like is used. Of course, the transparent material of the lid does not affect the polishing slurry, does not cause a chemical reaction with the polishing slurry, and needs to withstand the pressure when supplying and discharging the polishing slurry.

  The lid of the viewing window 9 is joined to the magnet strainer container 2 by a known joining means such as an adhesive or welding. The magnet strainer 3 includes an elongated bar-shaped magnet 10 and an iron removal ring 11 as described later. The magnet 10 is a magnet for adsorbing the magnetic metal in the polishing slurry, and is composed of a plurality of magnet elements (not shown). A holder 12 is attached to one end of the magnet 3. The holder 12 is used for inserting and removing the magnet strainer 3 from the magnet strainer container 2.

  The holder 12 is also used when cleaning the magnet 10. On the outer peripheral surface of the holder 12, a knurled surface, which is fine unevenness in a stitch shape, is formed by knurling. The operator cleans the magnet 10 by holding the knurled surface of the knurled holder 12 with one hand and moving the iron removal ring 11 with the other hand. The state of the magnetic material attached to the magnet 10 can be confirmed through the viewing window 9 from the outside of the strainer container 2 with the polishing slurry. When the amount of the magnetic material attached to the magnet 10 reaches a certain amount, the magnet strainer 3 is taken out of the strainer container 2 and cleaned.

  This cleaning is performed by relatively moving the magnet 10 and the iron removal ring 11 in the length direction of the magnet 10 as indicated by the arrows in FIG. 2 (details will be described later). . Further, when the amount of the magnetic material attached to the magnet 10 reaches a certain amount, the magnet 10 may be replaced with a magnet that has already been cleaned or is new. The place where the magnetic substance is most likely to adhere to the magnet strainer 3 is in the vicinity of the water inlet 7, and the viewing window 9 is preferably installed in the vicinity of the water inlet 7. Although the magnet 10 can be made into arbitrary length, what is the length installed along the whole magnet strainer container 2 is preferable.

  In particular, since the polishing slurry mainly flows between the water inlet 7 and the water outlet 8, it is preferable that the magnet 10 is installed between the water inlet 7 and the water outlet 8. The type, shape, and the like of the magnet strainer 3 and the magnet strainer container 2 are not particularly limited, but in the present embodiment, they are formed in an elongated cylindrical shape. The type of the magnet 10 is not particularly limited. For example, a magnet such as neodymium, ferrite, rare earth cobalt, and permalloy can be used. In particular, the magnet 10 is preferably a neodymium-based permanent magnet mainly composed of neodymium, iron, boron, or the like.

  The iron removal ring 11 is a magnetic body made of a steel material such as mild steel. The magnet 10 has a structure in which a permanent magnet magnet element and a spacer are placed in a tube. Although not shown, magnet elements and spacers are alternately arranged in the axial direction of the tube of the magnet 10, and adjacent magnet elements are arranged so that the same magnetic poles face each other. In other words, adjacent magnet elements are arranged so that the same poles are opposed and repelled, and are embedded in the tube (see, for example, JP-A Nos. 2002-195212 and 2001-9322).

  With such a structure, the magnetic poles of the adjacent magnet elements repel each other and generate a strong magnetic field around the magnet 10, and since this portion has a strong magnetic field, stainless steel fragments and iron pieces are concentrated and attracted. The iron removal ring 11 has an elongated cylindrical shape, and both sides thereof are opened. The iron removal ring 11 is fitted to the magnet 10 and can move the magnet 10 relatively up and down. The iron removal ring 11 has a rule 13 on one side. The ferrule 13 is a joint for piping like the ferrule 5 described above.

  When the iron removal ring 11 is fitted to the magnet 10, a slight gap is formed between the inside of the iron removal ring 11 and the magnet element. When the iron removal ring 11 relatively moves the magnet 10 in the long axial direction, the magnetic lines of force between the magnet elements of the magnet 10 flow to the magnetic body of the iron removal ring 11, and the magnet that has entered the iron removal ring 11. The spacer 10 loses its magnetic force, so that the foreign metal adhering to the outer periphery of the magnet 10 moves to the front end face of the iron removal ring 11. Finally, the metal foreign matter adhering to the outer periphery of the magnet 10 gathers on the front end surface of the iron removal ring 11 and is removed from the magnet 10 simultaneously with the movement of the iron removal ring 11. This state is indicated by a dotted line 18 in FIG.

  The applicant of the present invention discloses in Japanese Patent No. 3525093 a magnetized metallic foreign matter removing method and apparatus for removing metallic foreign matter attached to a bar magnet with a ring of magnetic material. This patent content applies to the magnet strainer 3 of the present invention. The ferrule 13 of the iron removal ring 11 is mounted on the ferrule 5 described above. Ferrule 13 and ferrule 5 are fixed by a clamp 15 via a gasket 14 therebetween. Thus, the inside of the magnet strainer container 2 is hermetically sealed.

  Ferrule 5 and ferrule 13 can be any ferrule. For example, a ferrule of a sanitary joint standardized by ISO (International Organization for Standardization) standard, JIS standard (Japanese Industrial Standard), IDF (International Dairy Federation) standard or the like can be used. The magnet 10 is fixed to the holder 12 with screws 16 or the like. The holder 12 may be a cap type to which a fixing screw or the like of the iron removal ring 11 is attached. A magnet strainer 3 is inserted into the strainer container 2, a gasket 14 is placed on the ferrule 5, a ferrule 13 is attached thereon, and the ferrule 5 and the ferrule 13 are fixed by the clamp 15 described above.

  Thereafter, the polishing slurry is injected from the water inlet 7, and the polishing slurry flows through the strainer container 2 and is discharged from the water outlet 8. When the polishing slurry flows through the magnet strainer container 2, it flows around the magnet 10, and during that time, a magnetic material such as iron contained in the polishing slurry adheres to the magnet 10. When taking out the magnet strainer 3 in the magnet strainer container 2, the clamp 15 is removed, the holder 12 is held, and the magnet strainer 3 is taken out.

  As shown in FIG. 3, an outline of a polishing apparatus 100 using the magnet strainer 1 of the present invention is illustrated. The polishing apparatus 100 includes a polishing machine 100, a polishing slurry tank 101, a magnetic strainer 1, and a pipe for flowing and transferring polishing slurry between these apparatuses. In FIG. 3, these pipes are indicated by solid lines, and the flow direction of the polishing slurry in the closed circulation path is indicated by arrows. Of course, although not shown, there are other devices such as a pump for forcibly circulating the polishing slurry.

As illustrated in FIG. 3, the polishing slurry is circulated and reused in the order of the polishing machine 101, the polishing slurry tank 102, the magnet strainer 1, and the polishing machine 101.
The polishing slurry tank 102 temporarily stores the polishing slurry discharged by being used for polishing by the polishing machine 101. The polishing machine 101 polishes a glass substrate (not shown) using the polishing slurry supplied from the polishing slurry tank 102. Thereafter, the polishing slurry used for polishing is returned to the polishing slurry tank 102 again.

  Here, the magnet strainer 1 is installed between the polishing slurry tank 102 and the polishing apparatus 101. However, the magnet strainer 1 can be installed in any place as long as it is within the closed circulation path of this polishing slurry. When the polishing slurry passes through the magnet strainer 1, metal foreign matters such as iron in the polishing slurry adhere to the magnet and are removed. The polishing machine 101 polishes the surface to be polished while automatically controlling a polishing pad (not shown). At this time, the polishing machine 101 performs polishing while supplying polishing slurry between the surface to be polished and the polishing pad.

  A glass substrate etc. can be illustrated as a surface to be polished. As the glass substrate, amorphous, chemically strengthened or crystallized glass which is usually used as a magnetic disk substrate can be used, and examples thereof include soda lime, aluminosilicate, lithium silicate, lithium aluminosilicate, aluminoborosilicate, and the like. . The polishing slurry uses a liquid that is optimal for polishing depending on the material of the surface to be polished. For example, a cerium oxide-based abrasive is preferable for polishing a glass substrate. Since the polishing pad, the polishing slurry, the polishing machine 101, the polishing slurry tank 102, and the like are not the main purpose of the present invention, detailed description thereof is omitted.

  When the magnet strainer 1 of the present invention is used, it is possible to easily confirm and estimate the time for cleaning or replacing the magnet, and thus the working efficiency of the polishing machine is improved. Eventually, polishing costs can be reduced. The polishing machine 101 polishes the surface to be polished using a polishing slurry, and this polishing means lapping or polishing. The polishing slurry is a polishing liquid in which fine particles such as cerium oxide, zirconium oxide, silicon dioxide, and aluminum oxide are dispersed in water or the like. In particular, in polishing a glass substrate, a polishing slurry using cerium oxide is desirable because of its high polishing rate.

[Others]
Foreign matters such as iron adhering to the magnet 10 can be easily seen with the naked eye when they are large in the order of submillimeters or millimeters. Since foreign matters such as iron adhering to the magnet 10 are used in the circulating polishing slurry, they are basically fine particles of the order of micrometers or less. Therefore, the foreign matter adhering to the magnet 10 is such that the tube on the outside of the magnet 10 is slightly changed in color. When such a magnet 10 is touched by hand, it feels slimy.

  Therefore, a scraper can be used instead of the iron removal ring 11 described above. As this scraper, the same cylindrical shape (ring shape) as that of the iron removal ring 11 can be used. The scraper is made of a non-magnetic material such as MC nylon or fluororesin. Since the magnetic foreign matter mixed in the polishing slurry for polishing has a small magnetic force, the magnet 10 is rubbed with a scraper to remove foreign matters such as iron powder adsorbed thereto.

  The iron removal ring 11 has a slight gap between the iron removal ring 11 and the magnet. However, if a scraper is used, the gap may be eliminated. In an extreme case, since the magnetic force of the foreign matter is small, the magnet 10 can be wiped off with a cloth or the like. When the water inlet 7 is installed in the upper part of the magnet strainer container 2, for example, when the water inlet 7 is installed instead of the water outlet 8 in FIG. 1, the viewing window is a dotted line in FIG. It is installed on the upper part of the magnet strainer container 2 like the illustrated viewing window 9a. In summary, the viewing window is installed near the water entrance.

[Second Embodiment]
Hereinafter, a magnet strainer and a polishing apparatus using the same according to a second embodiment of the present invention will be described. The structure and function of the magnet strainer and the polishing apparatus using the same according to the second embodiment of the present invention are basically the same as those of the magnet strainer 1 and the polishing apparatus 100 according to the first embodiment described above. Here, only different parts will be described. The magnet strainer of the second embodiment is the same as the magnet strainer 1 shown in FIGS. 1 and 2, and the magnet strainer container 2 is made of a transparent material.

  Therefore, it is not necessary to provide the viewing window 9 of the first embodiment in the magnet strainer container. The magnet strainer container of the second embodiment is made of glass, transparent acrylic resin such as polymethyl methacrylate resin (PMMA), polycarbonate resin (PC), polyphenylene sulfide (PPS), polybutylene terephthalate resin (PBT), etc. Is used. However, the material of the magnet strainer container is selected depending on the type of polishing slurry. For example, the polishing slurry is usually an aqueous solution and does not require much pressure in the magnet strainer container, so a material such as PC or acrylic resin can be used.

  When the polishing slurry is acidic, a material such as polyvinyl chloride (PVC) that can withstand acidity is preferable for the magnet strainer container. The material of the magnet strainer container is preferably workable in order to change the shape of the magnet strainer container or to join other parts. In the magnet strainer of the second embodiment, a transparent magnet strainer container is manufactured by any known manufacturing method. Each part of the magnet strainer may be manufactured separately and finally assembled. Further, the magnet strainer container 2, the ferrule 5, the water outlet 8, the water inlet 7, and the female screw 6a shown in FIG. 1 can be integrally manufactured by injection molding.

  The magnet strainer of the present invention is preferably used in the fields of semiconductor device manufacturing and liquid crystal screen manufacturing, in particular, polishing of glass, quartz, silicon wafers and the like.

DESCRIPTION OF SYMBOLS 1 ... Magnet strainer 2 ... Magnet strainer container 3 ... Magnet strainer 7 ... Water flow inlet 8 ... Water flow outlet 9 ... Viewing window 10 ... Magnet 11 ... Iron removal ring 100 ... Polishing apparatus 101 ... Polishing machine 102 ... Polishing slurry tank

Claims (8)

In a magnet strainer used in a polishing apparatus for polishing a surface to be polished using a polishing slurry,
The magnet strainer is
A container for allowing the polishing slurry to pass through, made of a transparent material, and a magnet strainer container provided with a viewing window for viewing the inside situation from the outside,
When the polishing slurry flows and passes through the inside of the magnet strainer container, it adsorbs the magnetic metal contained in the polishing slurry, and comprises a magnet inserted into the magnet strainer container. Magnet strainer to perform. In the magnet strainer according to claim 1,
The viewing window is installed in the vicinity of a water inlet of the magnet strainer container for introducing the polishing slurry into the magnet strainer container. In a magnet strainer used in a polishing apparatus for polishing a glass substrate using a polishing slurry,
The magnet strainer is
A container for passing the polishing slurry, a magnet strainer container made of a transparent material, and
When the polishing slurry flows and passes through the inside of the magnet strainer container, it is for adsorbing the magnetic metal contained in the polishing slurry, and comprises a magnet inserted in the magnet strainer container. Magnet strainer. The magnet strainer according to claim 1, selected from claims 1 to 3.
The magnet is provided with a magnetic material removal ring or a scraper made of a cylindrical non-magnetic material in order to clean the iron powder. In the magnet strainer according to claim 4,
The magnet has a magnet element that is a permanent magnet and a spacer that is a magnetic body arranged alternately in the axial direction of the tube, and is arranged so that the same polarity of the magnet element is opposed and repelled. Magnet strainer characterized by being made. In the magnet strainer according to claim 4 or 5,
The magnet has a holder;
A knurled irregularity is formed on the outer peripheral surface of the holder so that an operator can easily grip the magnet. A magnet strainer. The magnet strainer according to claim 1, wherein the magnet strainer is selected from claims 1 to 6.
The surface to be polished is a glass or quartz substrate,
The magnet strainer, wherein the polishing slurry is a cerium oxide-based slurry. The polishing apparatus using the magnet strainer according to claim 1 selected from claims 1 to 7,
The magnet strainer;
A polishing slurry tank for temporarily storing the polishing slurry;
A polishing machine for polishing the surface to be polished using the polishing slurry;
Pipes for transporting the polishing slurry between the polishing slurry tank and the magnet strainer, between the magnet strainer and the polishing machine, and between the polishing machine and the polishing slurry tank, respectively.
The polishing apparatus, wherein the polishing slurry circulates in a closed circulation path including the polishing slurry tank, the magnet strainer, the polishing machine, and the pipe.

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