WO2012031828A1 - Procédé de sciage d'une pièce - Google Patents

Procédé de sciage d'une pièce Download PDF

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Publication number
WO2012031828A1
WO2012031828A1 PCT/EP2011/063009 EP2011063009W WO2012031828A1 WO 2012031828 A1 WO2012031828 A1 WO 2012031828A1 EP 2011063009 W EP2011063009 W EP 2011063009W WO 2012031828 A1 WO2012031828 A1 WO 2012031828A1
Authority
WO
WIPO (PCT)
Prior art keywords
workpiece
sawing
sawing tool
tool
abrasive grains
Prior art date
Application number
PCT/EP2011/063009
Other languages
German (de)
English (en)
Inventor
Martin Schoepf
Original Assignee
Robert Bosch Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch Gmbh filed Critical Robert Bosch Gmbh
Publication of WO2012031828A1 publication Critical patent/WO2012031828A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28D—WORKING STONE OR STONE-LIKE MATERIALS
    • B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
    • B28D5/04—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by tools other than rotary type, e.g. reciprocating tools
    • B28D5/045—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by tools other than rotary type, e.g. reciprocating tools by cutting with wires or closed-loop blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H5/00—Combined machining
    • B23H5/02—Electrical discharge machining combined with electrochemical machining
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H5/00—Combined machining
    • B23H5/04—Electrical discharge machining combined with mechanical working
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H5/00—Combined machining
    • B23H5/06—Electrochemical machining combined with mechanical working, e.g. grinding or honing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B27/00—Other grinding machines or devices
    • B24B27/06—Grinders for cutting-off
    • B24B27/0633—Grinders for cutting-off using a cutting wire

Definitions

  • the present invention relates to a method for sawing a workpiece.
  • the invention particularly relates to a method for wire sawing a
  • Silicon workpiece for producing a silicon wafer Silicon workpiece for producing a silicon wafer.
  • wire sawing is often used. This is a mechanical separation process, especially for silicon, which is also referred to as separation lapping process with unbound cutting grain and undirected cutting edge.
  • the cutting grain is usually in a carrier medium, which forms a suspension together with the cutting grain, which is also referred to as slurry.
  • a usually thin wire with a diameter of 100 ⁇ to 180 ⁇ often serves as a tool. An unwinding reel winds the wire over
  • Wire guide rollers with a defined wire speed, until it is finally wound up again via a take-up reel.
  • the wire dips into the suspension and draws the slurry adhering to the wire surface into the kerf of the workpiece.
  • Slurry is additionally defined on the wire field via a nozzle.
  • the cutting grains are thus pulled with the help of the wire and with a defined processing speed through the kerf and tear small particles from the solid.
  • the workpiece dips into the wire field at the appropriate feed rate, whereby a cutting removal takes place.
  • the wire usually cuts many close together thin wafers, which may have a thickness of between 200 ⁇ and 300 ⁇ depending on the industrial application. Such a method is known, for example, from CH 696389 A5.
  • the achieved feed is about 0.4 mm / min, which often makes parallelizing the method economically sensible and necessary.
  • the present invention is a method for sawing a workpiece, in particular a silicon workpiece, wherein a sawing tool is displaced along the workpiece, wherein the sawing tool cooperates with the displacement of abrasive grains such that the abrasive grains cause a machining removal of the workpiece, and wherein between the workpiece and the sawing tool an electrical voltage to
  • a sawing tool is displaced along the workpiece, wherein the sawing tool in the displacement cooperates with abrasive grains such that the abrasive grains cause a machining removal of the workpiece, the material of the workpiece is first removed by an abrasive method and the workpiece thus sawed.
  • This mechanical sawing method is for the Sawing a workpiece even in small dimensions, such as those used for the production of power semiconductors, well suited.
  • the abrasive grains are firmly attached to the sawing tool, for example, and may be present as an abrasive grain coating, for example.
  • Cooperation of the sawing tool with the abrasive grains can therefore be effected by attachment of the abrasive grains to the sawing tool.
  • a displacement means in particular, that the sawing tool is moved along the intended cutting edge of the workpiece, wherein the abrasive grains rub against on the surface of the workpiece, in order to effect a machining removal of the workpiece.
  • a cutting removal means in particular that the removed material is obtained in the form of chips or particles.
  • an electrical voltage for stress-based removal of the workpiece is applied between the workpiece and the sawing tool.
  • the abrasive removal of the workpiece is therefore supported by a stress-based removal, whereby at least two removal processes are performed in parallel. This will be the
  • the feed rate ie the speed of displacement of the sawing tool along the surface of the workpiece can be increased.
  • feed rates of up to 1.5 mm / min can be achieved.
  • Such feed rates are suitable for both abrasive and stress-based removal of the workpiece.
  • the feed rate is high enough to work economically, and low enough to handle even the smallest workpieces with high accuracy.
  • the sawing tool and the workpiece serve as electrodes. It can thus be seen that the sawing tool and the workpiece should each be formed of an electrically conductive material. This has the advantage that the inventive method can be performed on existing sawing machines without a great deal of structural measures. Only one voltage source and possibly suitable insulators are needed.
  • the method according to the invention is in particular for sawing a
  • Silicon workpiece suitable.
  • other, electrically conductive workpieces can be sawn by the method according to the invention.
  • semiconductor workpieces such as gallium arsenide or
  • a method for sawing a workpiece is understood in particular as a method for separating or scoring a workpiece. By a sawing process can thus be separated from the workpiece or one or more parts of the workpiece or notches
  • a liquid can here on the one hand cool the sawing tool as well as the workpiece, which in particular in a cutting
  • the liquid can achieve a lubricating effect that minimizes the effort required to move the sawing tool. As a result, the sawing tool is spared. Consequently, the
  • Liquid have the function of a cooling lubricant.
  • Liquids include, for example, glycol or oil, such as a mineral or synthetic oil.
  • the liquid can serve as a carrier medium for abrasive grains, whereby a method according to the principle of the unbound grain, ie with cutting grains in the carrier medium, is possible.
  • Embodiment forms the carrier medium with the abrasive grains a Suspension or the slurry, wherein the abrasive grains are entrained in this case by the displacing sawing tool and thus cause a machining removal of the workpiece.
  • the interaction of the sawing tool with the abrasive grains can be effected by entrainment 5 of the abrasive grains by displacing the sawing tool.
  • a discharge arc for removing the workpiece is generated by the tension between the sawing tool and the workpiece.
  • the dielectric can be formed by the liquid. In this way, the formation of a suitable discharge arc can be ensured, which is not by an electrically conductive component between the sawing tool and the
  • Dielectric selected in particular from deionized water or an oil, such as a synthetic oil.
  • the workpiece is polarized as an anode and the sawing tool as a cathode to electron flow between the workpiece and the To enable sawing tool.
  • the sawing tool as a cathode to electron flow between the workpiece and the To enable sawing tool.
  • ECM Electrochemical Ablation
  • Increased removal rate compared to a mere abrasive removal of the workpiece is made possible by using an electrochemical removal of creating the most complicated spatial shapes.
  • machining with the highest precision in the micrometer range is possible with such a method. Further, after sawing, surfaces having a highest quality are obtained.
  • an electrolyte is arranged between the sawing tool and the workpiece.
  • the electrolyte may also be formed by the liquid. In this way, a sufficient flow of current between the sawing tool and the workpiece can be ensured, wherein the ions dissolved from the material of the workpiece migrate into the electrolyte. It is particularly preferred if the electrolyte is a
  • Particularly preferred electrolytes which can be used in the invention are in particular selected from an aqueous one
  • a joint thermal and electrochemical removal is performed in addition to the abrasive removal of the workpiece, essentially a so-called ECDM method takes place.
  • a substance in particular a liquid, should be arranged between the workpiece and the sawing tool, which has an electrical conductivity of ⁇ 10 mS / cm. In this way, the conductivity may be sufficiently high to provide at least a small electrical current between the
  • the sawing tool with distance to the workpiece along displaced this, the distance is determined in particular by the arrangement and / or thickness of the abrasive grains.
  • a distance between the tool and the saw-cutting piece is understood to mean that the outside of the sawing tool is not in direct contact with the workpiece. This is to be preferred in particular in the case of voltage-based or electrical removal methods, because these are in particular provided with a distance between the tool and the tool
  • the distance can be determined by the arrangement and / or thickness of the abrasive grains. In the case that the abrasive grains are attached to the sawing tool, the thickness of the abrasive grains are attached to the sawing tool.
  • Abrasive grains directly the distance between the sawing tool and the workpiece. In the embodiment in which the abrasive grains are in one
  • Carrier medium are located and are entrained by the shifting sawing tool, the distance must of course be chosen so that allow the entrained Abrasivkörner a machining removal of the workpiece by an action of the sawing tool. Therefore, the distance is also determined in this case by the arrangement, or thickness of the abrasive grains.
  • the sawing tool is selected from a copper, brass, graphite, tungsten or steel wire.
  • the sawing tool provides a sufficiently high stability, tensile strength and is electrically conductive, so that both an abrasive, as well as a voltage-based
  • the applied voltage is particularly preferably to be selected as a function of the type of stress-based removal of the workpiece.
  • the subject of the present invention is furthermore an apparatus for sawing a workpiece according to the independent claim. Further advantages and advantageous embodiments of the subject invention are illustrated by the drawings and explained in the following description. It should be noted that the
  • Fig. 1 is a schematic representation of an embodiment of the
  • Fig. 2 is a schematic representation of another embodiment of the method according to the invention.
  • FIG. 1 schematically shows the mode of operation of a device according to the invention
  • the method according to the invention can be used, in particular, to carry out a wire sawing on a silicon workpiece, for example to produce a silicon wafer.
  • the sawing tool 12 may in particular be a metal wire, such as a copper, brass, graphite, tungsten or steel wire.
  • a metal wire such as a copper, brass, graphite, tungsten or steel wire.
  • these metals are well suited for wire sawing.
  • these wires are electrically conductive as metals, which in particular for a
  • the sawing tool 12 or the metal wire can have a thickness in a range of> 100 ⁇ to ⁇ 180 ⁇ .
  • Workpiece 10 act on the workpiece 10 cutting grains or abrasive grains 14 a.
  • abrasive grains 14 By the action of the abrasive grains 14 on the
  • Workpiece 10 is sawn mechanically or abraded.
  • the abrasive grains 14 should be designed such that they can effect a machining removal of the workpiece 10 or of material of the workpiece 10 when acting on the workpiece 10.
  • the Abrasive grains 14 are for this purpose in particular particles which consist of silicon carbide or comprise this at least to a large extent.
  • Silicon carbide a material very similar to diamond, thus has a very high hardness, which can range from 9.6 (Mohs) and 2600 (Vickers, Knoop). Such a high hardness is to be preferred, so that the
  • Abrasive grain 14 is not damaged even during a sawing or wears too high a degree.
  • silicon carbide is also at temperatures above 800 ° C against oxygen to a high degree
  • Erosion is useful.
  • Other preferred materials that may include the abrasive grains 14 include diamond or cubic boron nitride (CBN).
  • the abrasive grains 14 are fixedly attached to the sawing tool 12, one speaks here of a sawing with bonded grain.
  • a sawing process automatically takes place when the sawing tool 12 is displaced along the surface of the workpiece 10, since the abrasive grains 14 thus act on the workpiece 10.
  • the sawing tool 12 is displaced at a distance from the workpiece 10 along this, wherein the distance is determined in particular by the thickness of the abrasive grains 14. It can by the sawing tool 12, a pressure in the direction of
  • the sawing tool 12 or its surface can always exactly keep the distance to the workpiece 10, which corresponds essentially to the thickness or the diameter of the abrasive grains 14, wherein a penetration depth of the abrasive grains 14 into the workpiece 10 is to be considered.
  • the distance between the sawing tool 12 and the workpiece 10 can be adjusted by the attachment of the abrasive grains 14 on the sawing tool 12 of the
  • Diameter of the abrasive grains 14 is selected, respectively, a plurality of layers of abrasive grains on the sawing tool 12 is arranged.
  • Workpiece 10 and thereby preferably by exerting a pressure of the sawing tool 12 in the direction of the arrow 16 or a pressure of the workpiece 10 in the opposite direction can thereby a notch 18, which illustrates the sawing process.
  • a substance 20, such as a liquid between the sawing tool 12 and the workpiece 10, which can serve as cooling lubricant and thus simplify the sawing process.
  • a voltage is applied between the sawing tool 12 and the workpiece 10, as is illustrated by the voltage source 22 in FIG.
  • the purely mechanical removal of the workpiece 10 can be supported by a stress-based or electrical removal and the removal rate and the process duration can be improved.
  • a discharge arc for removing the workpiece 10 can be generated by the tension between the sawing tool 12 and the workpiece 10.
  • the discharge arc respectively
  • a distance between the sawing tool 12 and the workpiece 10 is preferably to be selected so that a gap in a
  • a gap is formed in a range of approximately> 5 ⁇ m to ⁇ 100 ⁇ m in the case of an EDM and an ECDM method.
  • the gap preferably has a size in a range of about> 5 ⁇ to ⁇ 1000 ⁇ .
  • the exact gap size is preferably selected as a function of the applied voltage.
  • the abrasive grains 14 are formed of an electrically insulating material, such as silicon carbide, and are therefore on the
  • the substance 20 is preferably also a dielectric. This can then be selected in particular from deionized water or an oil. Both substances serve as a good insulator to one
  • an electrochemical or anodic removal of the workpiece 10 can take place.
  • the workpiece 10 can be polarized as an anode and the sawing tool 12 as a cathode.
  • an electrolyte can be selected.
  • the electrolyte can be selected in particular from an aqueous sodium chloride solution or an aqueous sodium nitrate solution.
  • the electrolyte preferably has an electrical conductivity in a range of> 5mS / cm to ⁇ 75mS / cm.
  • the thermal and the electrochemical removal method can be used equally in combination in addition to the abrasive method. In this case, therefore, the increase in the removal rate by a parallel use of a mechanical, thermal and a
  • Electrochemical removal possible In a hybrid process, ie a combination of thermal and electrochemical removal processes, the anodic dissolution of the material of the workpiece preferably acts during the ignition delay of the thermal process.
  • FIG. 2 shows a further embodiment of the method according to the invention.
  • the method according to FIG. 2 essentially corresponds to FIG

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Processing Of Stones Or Stones Resemblance Materials (AREA)
  • Mechanical Treatment Of Semiconductor (AREA)
  • Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)

Abstract

L'invention concerne un procédé de sciage d'une pièce (10), en particulier d'une pièce de silicium, dans le cadre duquel un outil de sciage (12) est déplacé le long de la pièce (10), l'outil de sciage (12) coopérant, lors du déplacement, avec des grains abrasifs (14) de telle sorte que les grains abrasifs (14) provoquent un usinage de la pièce (10) par enlèvement de copeaux. Une tension électrique destinée à usiner la pièce (10) par enlèvement de matière sur la base de la tension est appliquée entre la pièce (10) et l'outil de sciage (12). Grâce audit procédé selon l'invention, la vitesse d'usinage par enlèvement de matière est augmentée et la durée du processus réduite.
PCT/EP2011/063009 2010-09-10 2011-07-28 Procédé de sciage d'une pièce WO2012031828A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE201010040535 DE102010040535A1 (de) 2010-09-10 2010-09-10 Verfahren zum Sägen eines Werkstücks
DE102010040535.3 2010-09-10

Publications (1)

Publication Number Publication Date
WO2012031828A1 true WO2012031828A1 (fr) 2012-03-15

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2011/063009 WO2012031828A1 (fr) 2010-09-10 2011-07-28 Procédé de sciage d'une pièce

Country Status (3)

Country Link
DE (1) DE102010040535A1 (fr)
TW (1) TW201244860A (fr)
WO (1) WO2012031828A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017201047A1 (fr) * 2016-05-18 2017-11-23 The Board Of Regents Of The Nevada System Of Higher Education On Behalf Of The University Of Nevada, Las Vegas Dispositifs et procédés d'usinage à potentiel électrique
CN109773293A (zh) * 2019-03-30 2019-05-21 华侨大学 电火花线切割-金刚石线锯复合加工装置
CN114953229A (zh) * 2022-06-30 2022-08-30 青岛高测科技股份有限公司 一种线切割机的复合加工方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102013201932A1 (de) 2013-02-06 2014-08-07 Robert Bosch Gmbh Vorrichtung und Verfahren zum Bearbeiten eines Werkstücks
DE102013206195A1 (de) 2013-04-09 2014-10-09 Robert Bosch Gmbh Verfahren zum Erzeugen eines Sägewerkzeugs und Verfahren zum Sägen eines Werkstücks verwendend das Sägewerkzeug

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2825868A1 (de) * 1977-06-14 1979-01-11 Inoue Japax Res Bearbeitungsvorrichtung
DE10238593A1 (de) * 2002-08-22 2004-03-11 Wacker Siltronic Ag Verfahren zur Herstellung von Halbleiterscheiben
CH696389A5 (de) 2002-02-19 2007-05-31 Meyer & Burger Ag Maschf Drahtsäge.

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2825868A1 (de) * 1977-06-14 1979-01-11 Inoue Japax Res Bearbeitungsvorrichtung
CH696389A5 (de) 2002-02-19 2007-05-31 Meyer & Burger Ag Maschf Drahtsäge.
DE10238593A1 (de) * 2002-08-22 2004-03-11 Wacker Siltronic Ag Verfahren zur Herstellung von Halbleiterscheiben

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017201047A1 (fr) * 2016-05-18 2017-11-23 The Board Of Regents Of The Nevada System Of Higher Education On Behalf Of The University Of Nevada, Las Vegas Dispositifs et procédés d'usinage à potentiel électrique
CN109773293A (zh) * 2019-03-30 2019-05-21 华侨大学 电火花线切割-金刚石线锯复合加工装置
CN114953229A (zh) * 2022-06-30 2022-08-30 青岛高测科技股份有限公司 一种线切割机的复合加工方法

Also Published As

Publication number Publication date
DE102010040535A1 (de) 2012-03-15
TW201244860A (en) 2012-11-16

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