JP2007015076A - Method for removing punching chip of single crystal silicon plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for removing punching chips adhered to a groove of a punching tool such as a drill repeatedly used for punching to stably perform work of fine punching on a single crystal silicon plate, etc., while maintaining punching accuracy. <P>SOLUTION: In this method, the punching tool of a fine hole diameter on the single crystal silicon plate is inserted into a remover for removing punching chip constituted of a three-dimensional nonwoven fabric structural body made of synthetic resin of a core fiber and a flexible sheath fiber having a melting temperature lower than that of the core fiber by more than 30°C and fixed with micro polishing abrasive grain several times or dozens of times, to prevent damage or an breaking accident of the tool and maintain machining accuracy and machining stability. A punching work with stable punching accuracy can be performed by using the tool removed with the punching chip by a simple work repeating the removing work, while deciding a removing degree of the punching chip by magnified videos from a microscope 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a drilling method for preventing drilling accuracy and stability of a single crystal silicon plate, and a tool damage / breakage accident.
More specifically, the present invention relates to a drilling method in a drilling process of a crystalline silicon plate using a drilling tool having a drill groove, and scraping off drilling scraps from the drill groove of the tool generated at the time of drilling. The present invention relates to a drilling method for preventing stability and damage / breakage of a blade.

  Conventionally, as a method of drilling metal, resin, semiconductor silicon, and other materials, there is a method of drilling while rotating a rotating drilling tool such as a drill at a predetermined feed speed to these drilled objects. . In this method, if the drilling is continued for a long time, the cutting tool is deteriorated and the drilling ability is lowered. If drilling is continued using a defective cutting tool with reduced drilling capability, the drilling surface of the workpiece will not be smooth, the hole will be bent, chipping or cracking will occur, the hole diameter will change, etc. In addition, problems such as work interruption and material disposal due to damage or breakage of the cutting tool itself during drilling occur, resulting in a decrease in work efficiency.

  As a method for preventing a decrease in drilling accuracy or a decrease in drilling work efficiency that occurs as described above, Japanese Patent Application Laid-Open No. 2000-711, already filed by the present applicant, describes a drilling method and apparatus. It is disclosed that a small diameter drill is used to measure the reaction force, and surface treatment is performed to increase the drilling ability of the cutting tool when the reaction force exceeds a set value. was there. Japanese Patent Laid-Open No. 9-11050 discloses that a low frictional silicon-reinforced diamond-like carbon coating layer is formed in a drill groove to promote the discharge of drilling scraps. It was not enough to discharge the agglomerated material or drilling waste.

  Furthermore, in the field of semiconductor manufacturing, many parts made of single crystal silicon are used, and this is often performed by drilling, and in recent years, the hole diameter has become smaller and the hole bottom has become deeper. Yes. For this reason, a problem in semiconductor manufacturing processing is the discharge / removal of drilling debris from a small diameter tool (drill). In particular, in the case of high-purity silicon, drilling debris adheres due to heat during drilling, and the discharge path becomes narrow and the discharge of drilling debris is hindered, resulting in lower drilling accuracy, instability during drilling, and tool breakage. There was a fear.

  If drilling is continued as described above, problems such as poor accuracy such as an increase in drilling diameter and broken tools often occur. Conventionally, there is a method of scraping off drilling chips adhering to tools such as a drill by piercing the tool vertically into a soft metal such as aluminum and drilling it. However, it was not suitable as a method for removing perforated debris.

  Further, as a drill polishing device, a rotating grindstone having a polishing surface inclined at a predetermined angle with respect to the drill, a spindle that holds the drill in a horizontal motion reciprocating in a direction parallel to the polishing surface, Japanese Patent Laid-Open No. 5-253720 discloses a polishing apparatus that performs polishing while synchronizing back-and-forth movement back and forth in a direction perpendicular to the rotation axis and rotation movement for rotating a drill held by the spindle. Japanese Patent Application Laid-Open No. 9-262710 discloses an apparatus that ejects fluid from a nozzle hole to drilling debris adhering to a shank of a drill by high pressure. However, these apparatuses have a problem that not only the drilling operation becomes complicated but also the price of the apparatus increases, and there has been a demand for a method for easily removing drilling debris adhering to a tool such as a drill.

JP 2000-000711 A Japanese Patent Application Laid-Open No. 09-011050 JP 05-253720 A JP 09-262710 A

  The present invention has been made in view of the above circumstances, can be easily introduced into the drilling process, has no fear of impurity contamination on the work plate, and moreover efficiently removes sticky drilling scraps to the tool. This is a removal method in which removal / peeling and drilling are smoothly performed to prevent breakage of a cutting tool having a drill groove as much as possible.

In order to achieve the above object, the present invention provides a tool that is inserted into a remover in which fine abrasive grains are fixed to a three-dimensional nonwoven fabric structure composed of a core fiber and a sheath fiber, and is moved back and forth so that it remains in the drill groove. The perforated waste is removed by scraping or scraping off the perforated waste.
Since the fine abrasive grains are randomly fixed to the sheath fiber surface layer constituting the remover, when the sheath fibers come into contact with the drill groove of the tool, the presence of the fine abrasive grains causes the drilling chips in the drill groove to be drilled. Can be efficiently removed. In addition, when the drilling tool is attached to the main body, it is appropriate to insert the drilling tool in a substantially right angle direction with respect to the remover in the mounted state. Can be stabbed. Since the fibrous body (layer) to which the fine abrasive grains are fixed is flexible, the fine abrasive grains can be prevented from coming into contact with the tool with an excessive force, and a breakage accident of the drilling tool can be prevented.

That is, the present invention has the following configuration as a basic configuration.
(1) A method for removing silicon drilling debris from a drilling tool groove in a drilling step of a crystalline silicon plate using a drilling tool having a drill groove, wherein the tool is inserted into a drilling scrap removing remover a plurality of times, and the groove portion A method for removing perforated debris from a silicon plate, wherein the removal operation is performed while electronically processing / enlarging the optical system image while determining the perforated debris removal state of the groove with the naked eye.
(2) The silicon plate according to (1), wherein the remover for removing perforated scraps is formed by fixing fine abrasive grains to a three-dimensional nonwoven fabric structure composed of core fibers and sheath fibers and sheath fibers. For removing perforated debris.
(3) The method for removing drilling scraps from a silicon plate according to (1) or (2), wherein the number of times the punching tool is inserted into the removal remover is several to dozens.
(4) The perforated waste removal method according to any one of the above (1) to (3), wherein a plurality of perforated waste removal removers are stacked to remove perforated waste.
In the drilling process employing the above removal method, when the reaction force during drilling exceeds a predetermined value, the machining operation is interrupted, and the removal result of the drilling debris is confirmed by image determination. In consideration of this relationship, the entire drilling process can be managed, so that productivity and drilling accuracy can be improved.

(Detailed description of the invention)
The member used in the method for removing drilling debris from the drilling tool generated when fine drilling is performed on the single crystal silicon plate of the present invention comprises a three-dimensional nonwoven structure having fine abrasive grains on the surface of the constituent fibers. Although the removal tool for removing the drilling scraps is used, the removal effect of the drilling scraps adhered to the drill groove of the drilling tool is not impossible by visual observation, but is determined by an enlarged image of the optical system image.
The three-dimensional nonwoven fabric structure used in the remover for removing perforated scraps of the present invention is a nonwoven fabric formed from chemical fibers that are fixed by mechanical or chemical bonding treatment or a combination of the two, such as fibers. That is, the three-dimensional nonwoven fabric structure having a fiber surface coated with a thermosetting resin containing fine abrasive grains is fixed.

As the nonwoven fabric structure used in the present invention, Japanese Patent Application Laid-Open No. 59-129046 discloses an antibacterial agent-containing nonwoven fabric cleaner, and Japanese Patent Application Laid-Open No. 2002-263043 discloses a puncture resistance load and an initial puncture resistance degree in a nonwoven fabric convex portion. Non-woven fabric for wiping provided with a convex portion in which a thermoplastic fiber satisfying a desired range is softened or melted and a concave portion subjected to thermocompression bonding in a nonwoven fabric surface layer portion is disclosed in JP-A-4-166123 as a core component and a core component Although a wiping cloth made of a non-woven fabric composed of a plastic with a sheath component lower by 30 ° C. is disclosed, all of these techniques utilize only the horizontal abrasiveness of the cleaner surface, that is, the surface. However, in the present invention, the abrasiveness in the vertical direction is utilized.
Further, as the removal remover containing abrasive particles, JP-A-56-91077, JP-A-59-129046, JP-A-62-152426, JP-A-62-152427, etc. The nonwoven fabric is impregnated with a resin binder containing abrasive particles, sprayed, or coated, heated and dried, and used for cleaning purposes. This is a method for horizontally moving and scraping the surface of the nonwoven fabric in which the abrasive is present, and there is a problem that the abrasive binder is easily peeled off.

  On the other hand, in the present invention, since the tool is inserted into the cleaner or remover in a substantially vertical direction, the uneven microstructure formed by the entanglement of the fibers inside the nonwoven fabric structure can be used, so that adhesion by drilling of the crystalline silicon plate is possible. It became possible to completely remove waste and grinding waste.

The three-dimensional nonwoven fabric structure in the remover for removing perforated scraps used in the present invention will be described in detail. As disclosed in JP-A-4-136252, the sheath portion has a core-sheath structure containing fine abrasive grains. It has the characteristics using a composite fiber. Various synthetic resins such as polyester, polypropylene, and polyamide are used for the core component, and it is preferable to use a sheath resin having a melting point of at least 30 ° C. below the melting point of the core fiber synthetic resin. The synthetic resin of the core fiber and the sheath fiber is preferably the same, but different synthetic resins may be used as long as they have affinity. Specific examples of the sheath fiber include polystyrene, polyethylene, polypropylene, polyamide, and ethylene propylene copolymer.
In any case, the remover for removing the drilling scrap has an appropriate hardness so that the non-woven fabric-forming fiber enters the drill groove when the drilling tool to which the drilling scraps are stuck is inserted in a direction substantially perpendicular to the plane of the remover. It is preferable that it is made of a soft material.

  Examples of the fine abrasive grains fixed to the sheath fibers of the three-dimensional nonwoven fabric structure used in the present invention include inorganic mineral-based and resin-based high-hardness polymer pulverized products. Specific examples of inorganic mineral-based fine abrasive grains include calcium carbonate, aluminum oxide, calcium sulfate, silicon oxide, cerium oxide, zirconium oxide, chromium oxide and diamond. Specific examples of the resin-based fine abrasive grains include polyvinyl chloride, ABS resin, and polypropylene.

  Further, in the three-dimensional nonwoven fabric structure in the remover for removing drilling scraps used in the present invention, the sheath and the core part are continuously changed in the front and back parts and the central part. In some cases, one removal remover is used, or when removing the drill tip without removing it from the tool like a drill, removing two to three removal removers that adhere to the drilling tool Can also be used. Further, it is preferable to remove the drilling scraps by inserting the drill with drilling scraps into the drilling scrap removing remover several times to dozens of times.

  Thus, the degree of removal of drilling debris adhered to a tool such as a drill can be confirmed by the determination device shown in FIG. For example, the remaining state of the drilling scrap adhered to the groove of the drilling tool (drill) is visually observed to confirm the removal degree of the drilling scrap, but the enlarged image with a microscope or the like may be directly observed with the naked eye, The degree of removal of perforated dust may be confirmed by observing an enlarged image on a display such as a monitor TV.

In the present invention, since the tool is inserted into a cleaner or remover in a substantially vertical direction, the uneven microstructure formed by the entanglement of the fibers inside the nonwoven structure can be used, so that adhesion scraps and grinding scraps due to drilling of the crystalline silicon plate can be removed. Complete removal is possible.
It can also be disposable like an abrasive nonwoven used for cleaning purposes. Further, in the drilling process of the present invention, when the reaction force applied to the tool at the time of drilling exceeds a certain value, the machining work is interrupted, and the removal effect by the drilling scrap removal work is confirmed by image determination, Since the relationship with the drilling speed is also taken into consideration and the entire drilling process can be managed, the productivity and accuracy of drilling can be improved.

(Example)
Hereinafter, the removal method of the present invention will be described in detail by way of examples.

  Polyester to which zirconium oxide is fixed using the drilling blade for drilling, which has been drilled into a single-crystal silicon plate using a drilling drill having a diameter of 0.5 mm, to which drilling debris is attached to the drill groove. Repeated piercing into a 10 mm thick drilling scrap removing remover made of a three-dimensional nonwoven structure composed of sheath fibers and polypropylene core fibers, and each time the drilling scraps adhering to the drill drill groove were magnified with a microscope. The image was observed on a television and the degree of removal of drilling debris was confirmed. It was confirmed that the drilling debris was completely removed from the groove of the drilling drill in seven times. Thus, it was shown that when a single crystal silicon plate was drilled using a drill for drilling from which drilling debris had been removed, drilling with stable accuracy was obtained.

  Table 1 shows the degree of removal with respect to the number of times the drilling dust adhered to the drilling drill groove in the above example is inserted into the remover.

Drills for printed wiring boards with a diameter of 0.3 mm with drilling scraps adhering to the torsion grooves, silicon oxide powder adhered to fine abrasive grains, and sheath fibers made of polyester with thermosetting resin, and drilling using polyamide as the core fiber When the number of times of piercing was performed 5 times with 3 pieces of scraper removal piled up, it was confirmed by the enlarged image on the display in conjunction with the microscope that the drilling waste adhering to the twisted groove was completely removed. did it.
That is, when the drilling waste accumulated in the drill groove of the tool was observed by electronically processing and magnifying the fine optical system image from the microscope, the drilling waste at the tool tip and the groove was completely removed.

Flow chart of an apparatus for determining the degree of removal of drilling debris from a drilling tool

Explanation of symbols

(1) naked eye (2) microscope or magnifier (3) electronic processing device (4) display (view magnified image)
(5) Drill drill (6) Spindle

Claims (4)

  A method for removing silicon drilling debris from a drilling tool groove in a drilling step of a crystalline silicon plate using a drilling tool having a drill groove, wherein the tool is inserted into a drilling scrap removing remover a plurality of times, and an optical system for the groove A method for removing perforated waste, characterized in that the removal operation is performed while the image is electronically processed / enlarged and the perforated waste removed state of the groove is determined with the naked eye.   2. The method for removing perforated waste according to claim 1, wherein the remover for removing perforated waste comprises a three-dimensional nonwoven fabric structure comprising core fibers and sheath fibers, and fine abrasive grains fixed to the sheath fibers. .   3. The method for removing drilling waste from a silicon plate according to claim 1 or 2, wherein the number of times the punching tool is inserted into the removal remover is several to dozens.   The perforated waste removal method according to any one of claims 1 to 3, wherein a plurality of perforated waste removing removers are stacked to remove perforated waste.

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