JP5463025B2 - Vacuum suction pad and vacuum suction device - Google Patents

Description

  The present invention relates to a vacuum suction pad made of porous carbon, and a vacuum suction device including the vacuum suction pad and a holder for holding the pad, and more particularly to prevent scratches and dirt on an object to be processed. The present invention relates to a vacuum suction pad and a vacuum suction device that realize low dust generation.

  In the manufacturing process of semiconductors and liquid crystals, a vacuum suction device using a vacuum suction force is used to fix an object to be processed such as a semiconductor wafer or a glass substrate. Vacuum suction pads made of quality ceramics are widely used. However, in recent years, a vacuum suction pad made of porous carbon has been proposed as a lightweight and conductive pad in order to cope with an increase in the size of an object to be processed and a precise process.

  And in vacuum suction pads made of porous carbon, carbon is softer than ceramic (here, Vickers hardness), so if the workpiece is repeatedly adsorbed and released, the pad will be damaged or worn. Therefore, there is a concern that the adsorptive power will be reduced, or that abrasion powder will be generated to contaminate the object to be processed. In order to eliminate the concern, the following pads have been proposed.

  As an example, sufficient strength and emission can be obtained by coating the surface of a self-sintering carbon skeleton that forms a vacuum suction pad made of porous carbon (referred to as a porous carbon plate in Patent Document 1) with a thermosetting resin. A vacuum suction pad that suppresses dust has been proposed (see, for example, Patent Document 1).

  Also, one protective film of DLC, TiN, TiCN, TiAlN, TiCrN, CrN, and Cr is formed on the surface of the vacuum suction pad made of porous carbon (referred to as the suction surface of the porous carbon plate in Patent Document 1). Thus, a vacuum suction pad is proposed in which the pad surface is reinforced and dust generation is prevented (see, for example, Patent Document 1).

Furthermore, as a vacuum suction pad made of porous ceramics that is not carbon, a water-repellent resin, for example, a fluororesin, is deposited on each crystal particle that is sintered with each other to form the pad ( There has been proposed a vacuum suction pad that prevents water from adhering to a vacuum suction member in Patent Document 2 and prevents the pad from being clogged with polishing dust (see, for example, Patent Document 2).
Japanese Patent Laying-Open No. 2005-347689 (paragraphs 0027 and 0046) JP 2007-201363 A (paragraphs 0019, 0023, 0042)

  Since the vacuum suction pad according to Patent Document 1 is softer than ceramic, the skeleton surface of self-sintering carbon is made of a thermosetting resin for the purpose of reinforcing the vacuum suction pad made of porous carbon, or The surface of the vacuum suction pad is coated with a ceramic material such as TiN.

  The vacuum suction pad according to Patent Document 1 can suppress a decrease in suction force and dust generation caused by damage or wear of the pad to a predetermined standard or less even if the workpiece is repeatedly sucked and released. is there.

  However, since the precision of semiconductors and liquid crystals has been improved in recent years, it is expected that a vacuum suction pad with low dust generation superior to current standards will be desired in the future.

  In addition, in the post-manufacturing process of semiconductors and liquid crystals, the object to be processed is adsorbed to the vacuum suction pad via the protective film. In recent years, there is a new demand that the protective film does not want to have an adsorption mark or contact scratch. .

  Furthermore, in recent years, there is a new demand for using vacuum suction pads made of porous carbon in addition to semiconductor and liquid crystal manufacturing processes, so even if the workpiece is softer than a semiconductor wafer or glass substrate, A vacuum suction pad that does not damage objects is also desired.

  On the other hand, since the vacuum suction pad according to Patent Document 2 is originally a vacuum suction pad made of porous ceramic, there is no problem of reinforcement unlike a vacuum suction pad made of porous carbon.

  Accordingly, the present invention relates to a vacuum suction pad made of porous carbon, and a vacuum suction device including the vacuum suction pad and a holder for holding the pad, and more particularly to an object to be processed. An object of the present invention is to provide a vacuum suction pad and a vacuum suction device that can prevent scratches and dirt from being generated and realize further low dust generation.

  In order to solve the above-mentioned problems, in the invention according to claim 1, the surface of the vacuum adsorption pad made of porous carbon that adsorbs and holds the workpiece on its surface and communicates with the vacuum source on its back surface is covered with a fluororesin. did.

  In the invention according to claim 2, the fluororesin is a conductive fluororesin.

  In the invention according to claim 3, the vacuum suction device is configured to include a vacuum suction pad whose surface is coated with a fluororesin or a conductive fluororesin, and a holder for holding the vacuum suction pad.

  According to the first aspect of the present invention, the surface of the vacuum suction pad made of porous carbon that is adsorbed and held on the front surface and communicated with the vacuum source on the back surface is covered with the fluororesin. An object can be adsorbed to the pad through a fluororesin coating. Here, since the fluororesin is softer than the semiconductor wafer or glass substrate that is the object to be processed, the object to be processed and the protective film are less likely to be adsorbed or contacted.

  Further, since the fluororesin has non-adhesiveness, low friction, and lubricity, the object to be processed can be easily peeled off from the pad, and the object to be processed is hardly damaged.

  Further, since the fluororesin has water repellency, the pad is hardly soiled and can be easily washed away.

  Furthermore, since the surface of the vacuum suction pad is coated with a fluororesin, even if the machining powder generated in the pad manufacturing process remains inside the pad, the machining powder is less likely to generate dust. It is possible to prevent the object to be processed from becoming dirty with the processed powder.

  Further, as described above, since the workpiece is not damaged, dust generation from the workpiece can be suppressed.

  According to the second aspect of the present invention, since the fluororesin is made of a conductive fluororesin, there is no possibility that the pad loses the original conductivity of the carbon material.

  According to the invention of claim 3, the vacuum suction device is configured to include a vacuum suction pad whose surface is covered with a fluororesin or a conductive fluororesin, and a holder that holds the vacuum suction pad. Therefore, it is possible to provide a vacuum suction device having the effects described above.

  First, a basic matter of creation of the present invention will be briefly described. Regarding the vacuum adsorption pad made of porous carbon, the inventors maintain excellent adsorption power by covering the pad with a material generally harder than porous carbon, such as thermosetting resin or ceramic material, in Patent Document 1 described above. As a result, it was possible to reduce dust generation below a predetermined standard. Further, as a result of subsequent research, when self-sintering carbon is used as the pad material as in Patent Document 1, excellent adsorption force is maintained and dust generation can be achieved without coating with a thermosetting resin or ceramic material. It has also been confirmed that can be kept below a predetermined standard.

  However, in the future, it is expected that a vacuum suction pad with low dust generation that is superior to the current standards will be desired, and the protection film does not want to have suction marks or contact scratches. Focusing on the new demand for adsorbing soft materials, we have been studying vacuum suction pads and vacuum suction devices that can prevent scratches and dirt on the workpiece and achieve even lower dust generation.

  The inventors believe that a vacuum suction pad made of porous carbon is harder than porous carbon, and cannot be used unless it is reinforced by coating with, for example, a thermosetting resin or ceramic material. However, we have found that the porous carbon currently used can maintain the strength exceeding the standard without reinforcement.

  Further, the inventors paid attention to the fact that dust generation does not completely disappear even when the pad is covered with a thermosetting resin or a ceramic material, and thought that this dust generation was caused by the workpiece being damaged. He came up with the idea of covering the pad with something softer than porous carbon.

  Furthermore, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-347689, paragraph 0016), the inventors have used a fluororesin used as a shielding film for a holder (referred to as a sealing treatment portion in Patent Document 1). It has been found that a thin film can be formed by applying by air spray coating, and the air permeability of the pad is not hindered, and the present invention has been created.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is an exploded perspective view of the vacuum suction device according to the embodiment, and FIG. 2 is a cross-sectional view of the vacuum suction device according to the embodiment.

  As shown in FIG. 1, the vacuum suction apparatus 1 includes a vacuum suction pad 2 made of porous carbon and a holder 3 (hereinafter referred to as a holder) 3 having a suction hole 31 leading to a vacuum source (not shown). A film F made of a fluororesin is formed on the surface (hereinafter referred to as the surface) of the vacuum suction pad 2 that holds the workpiece W by suction. The vacuum suction device 1 is configured to suck and fix the workpiece W on the surface of the vacuum suction pad 2 by applying a negative pressure from a vacuum source.

  The vacuum suction pad 2 is a pad made of porous carbon and has a disk shape here, but the shape may be circular or square. The vacuum suction pad 2 is configured such that the front surface sucks and holds the workpiece W and the back surface communicates with a vacuum source (not shown).

  The coating F is made of a fluororesin, and here is polytetrafluoroethylene (hereinafter referred to as PTFE), but a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) or a tetrafluoroethylene / hexafluoropropylene copolymer. Various fluororesins such as (FEP) may be used. Carbon black is added to the PTFE here. Therefore, the film F has the same black color as the pad and also has conductivity.

  The conductive fluororesin refers to a material in which a carbon material such as carbon black or carbon fiber, or a metal oxide such as titanium oxide or tin oxide is added to the fluororesin.

  The holder 3 is a tray-like container that holds the vacuum suction pad 2 and has a suction hole 31 that communicates with a vacuum source (not shown) on the bottom surface thereof.

  In the vacuum suction apparatus 1 configured as described above, a film F made of a fluororesin is formed on the surface of the vacuum suction pad 2 as shown in FIG. For this purpose, the workpiece W is attracted to the vacuum suction pad 2 through the coating F.

  Subsequently, a vacuum suction apparatus according to another embodiment of the present invention will be described focusing on the differences. FIG. 3 is a perspective view of a vacuum suction apparatus 1 ′ according to another embodiment, and FIG. 4 is a cross-sectional view of a vacuum suction apparatus 1 ′ according to another embodiment.

  As shown in FIGS. 3 and 4, in a vacuum suction apparatus 1 ′ according to another embodiment, a coating F ′ is formed on the surface of the vacuum suction pad 2 and the upper surface of the peripheral edge of the holder 3. Therefore, the workpiece W is attracted to the vacuum suction pad 2 via the coating F ′.

  Next, a method of covering the surface of the vacuum suction device 1 according to the embodiment, more specifically, the vacuum suction pad 2 with a fluororesin will be briefly described. First, the vacuum suction pad 2 that has been polished to adjust the flatness is washed to remove the processing powder generated in the manufacturing process, and then dried.

  And the commercially available fluororesin was apply | coated to the surface of the cleaned pad with the spray gun, it was made to dry, the solvent contained in a fluororesin was evaporated, and it baked after that.

  On the other hand, for the vacuum suction device 1 ′ according to another embodiment, after the vacuum suction pad 2 is attached to the holder 3, the surface of the vacuum suction pad 2 and the upper surface of the peripheral edge of the holder 3 are simultaneously polished to obtain flatness. The method is the same except that the fluororesin is applied after preparation.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, the coatings F and F ′ according to the present invention are not limited to those applied by air spray coating, and any coating method may be used as long as a thin coating that does not impair the air permeability of the pad can be formed. .

  In the present invention, the fluororesin includes tetrafluoroethylene / ethylene copolymer (ETFE), chlorotrifluoroethylene / ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), etc. in addition to the PTFE, PFA, and FEP. Various fluororesins may be used.

  In the present invention, the conductive fluororesin may be any resin in which a carbon material such as carbon black or carbon fiber or a metal oxide such as titanium oxide or tin oxide is added to the fluororesin.

It is a disassembled perspective view of the vacuum suction apparatus which concerns on embodiment. It is sectional drawing of the vacuum suction apparatus which concerns on embodiment. It is a perspective view of the vacuum suction apparatus which concerns on other embodiment. It is sectional drawing of the vacuum suction apparatus which concerns on other embodiment.

Explanation of symbols

1,1 'Vacuum suction device 2 Vacuum suction pad 3 Holder
F, F 'coating

Claims (3)

A vacuum suction pad made of porous carbon that adsorbs and holds an object to be processed on its front surface and communicates with a vacuum source on its back surface,
A vacuum suction pad, wherein the surface of the vacuum suction pad is coated with a fluororesin.   The vacuum suction pad according to claim 1, wherein the fluororesin is a conductive fluororesin.   A vacuum suction apparatus comprising: the vacuum suction pad according to claim 1 or 2; and a holder for holding the vacuum suction pad.

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