JP2017007048A - Holding device and wire electric discharge machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure even electric conduction performance with a workpiece up to completing a slice, without dropping a workpiece even after completing the slice, when slicing by electric discharge machining, by sending out the workpiece in the wire row direction from an upper part.SOLUTION: A holding device is used in electric discharge machining for slicing a workpiece by a juxtaposed wire, and holds the workpiece when sending out the workpiece in the gravity direction, and comprises a conductive member electrically conducted with the workpiece, and an electric conduction area for electrically conducting between the workpiece and the conductive member and an adhesive area for fixing the workpiece by an adhesive, are respectively provided in a first interface for contacting the conductive member and an upper plane of the workpiece. An electric conduction area is also provided in an area where the juxtaposed wire can discharge up to finishing the slice so that the workpiece in the first interface becomes a plurality of workpieces, and the adhesive area is provided in an area capable of adhering the plurality of wire pieces even when finishing the slice so that the workpiece in the first interface becomes the plurality of workpieces.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a technique of a holding device and a wire electric discharge machining apparatus.

Conventionally, a wire saw is known as an apparatus for slicing a silicon ingot into a plate-like wafer. Recently, there is a technique for slicing a workpiece into a thin plate using a wire electric discharge machining technique.
Patent Document 1 discloses a technique in which an adhesive double-sided tape and an adhesive region are provided on an adhesive surface between one surface of a slice base and an ingot.

  When slicing the ingot by pushing it down into the wire row with a wire saw, it can be processed by bonding the interface between the ingot and the slice base so that the ingot does not fall into the slice. If the slice base is not energized, a machining current does not flow on the discharge circuit and a discharge failure occurs. Therefore, a material to be energized is required at the interface between the ingot and the slice base.

JP 2005-183839 A

  When the work is fed from the top in the wire row direction and sliced into work pieces by electrical discharge machining, if the work is attached to the slice base using conductive double-sided tape, the electrical conductivity can be secured, but the adhesive strength of the double-sided tape Then, it falls without being able to withstand the weight of the workpiece, and cannot be applied to a large workpiece with a weight of several kg.

  In addition, when the workpiece is bonded to the slice base with an adhesive, depending on the type and characteristics of the adhesive, for example, the epoxy adhesive used in a wire saw is non-conductive, so the electrical conductivity with the slice base cannot be secured. On the other hand, the conductive adhesive has a problem that it is difficult to peel the ingot from the slice base after slicing.

  The invention of the present application has a mechanism that, when a workpiece is fed from the top in the wire row direction and sliced by electric discharge machining, the workpiece piece is not dropped even after the slicing is completed, and the conductivity with the workpiece can be secured until the slicing is completed. The purpose is to provide.

  The present invention is a holding device that is used in electric discharge machining for slicing a workpiece with wires arranged in parallel, and holds the workpiece when the workpiece is fed in the direction of gravity, and includes a conductive member that energizes the workpiece. In the first interface where the conductive member and the upper flat surface of the workpiece are in contact, an energized region where the workpiece and the conductive member are energized and an adhesive region where the workpiece is fixed with an adhesive are provided. The energized region is provided in a region in the first interface where the arranged wires can be discharged until slicing is completed so that the workpiece becomes a plurality of workpiece pieces, The bonding area is provided in an area in the first interface where the plurality of wire pieces can be bonded even when the slicing is finished so that the work becomes a plurality of work pieces. And features.

  The present invention is a wire electrical discharge machining apparatus that slices a plurality of workpiece pieces by feeding the workpiece in the direction of gravity and performing electrical discharge machining of the workpiece with wires arranged in parallel, and includes a conductive portion that energizes the workpiece. In the first interface where the conductive portion and the upper flat surface of the work are in contact, an energization area where the work and the conductive member are energized and an adhesion area where the work is fixed with an adhesive are provided. The energized region is provided in a region in the first interface where the arranged wires can be discharged until slicing is completed so that the workpiece becomes a plurality of workpiece pieces, The bonding region is provided in a region in the first interface where the plurality of wire pieces can be bonded even when slicing is completed so that the workpiece becomes a plurality of workpiece pieces.

  In the present invention, when the work is sent from the upper part in the wire row direction and sliced by electric discharge machining, the work piece is not dropped even after the slicing is completed, and the continuity with the work can be secured until the slicing is completed. It becomes possible to provide.

The figure which looked at the wire electric discharge machining apparatus of this invention from the apparatus front direction. The figure which looked at the shape of the work piece before slicing or the work piece after slicing from the device front direction with the wire electric discharge machining device of the present invention. In this invention, the figure which looked at the relative position of the workpiece | work piece and wire row | line at the time of completion of a slice from the apparatus front direction. In this invention, the figure which looked at the relative position of the workpiece | work piece and wire row | line at the time of completion of a slice from the apparatus side surface direction. In this invention, the figure which looked at the relative position of the workpiece | work piece and wire row | line at the time of completion of a slice from the apparatus upper surface direction. In this invention, the figure which looked at each relative position of the holding | maintenance apparatus before a slice start, a workpiece | work, and a wire row from the apparatus side surface direction. The figure showing the surface where the side plate of this invention contacts the side surface of a workpiece | work. The figure showing sectional drawing of the side board of this invention.

  Referring to FIG.

  FIG. 1 is a diagram showing a configuration of a wire electric discharge machining system according to the present invention. The wire electric discharge machining system includes a wire electric discharge machining device 1, a power supply device 2, and a machining fluid supply device 12. The configuration of each mechanism shown in FIG. 1 is an example, and it goes without saying that there are various configuration examples depending on the purpose and application.

  The wire electric discharge machining system can slice the workpiece 105, which is a workpiece, into a thin plate at intervals between the wires 103 arranged in parallel by electric discharge machining. The present invention relates to a wire electric discharge machining apparatus for machining a workpiece 105 with wires 103 arranged side by side. In the wire electric discharge machining apparatus 1, a workpiece feed unit 3 driven by a servo motor is provided on an upper portion of the wire 103. The workpiece 105 (also referred to as an ingot) can be moved in the direction. In the present embodiment, the workpiece 105 is sent downward and electric discharge machining is performed, but as a modification, the workpiece 105 is moved upward to perform electric discharge machining by providing the workpiece feeding unit 3 below the wire 103. Also good.

  The power supply device 2 applies electrical discharge machining to the workpiece 105 by applying a pulse voltage between the electrodes of the wire 103 and the workpiece 105 arranged in parallel. The power supply device 2 is controlled so as to keep the discharge gap (between the poles) at a constant distance in order to move the work feeding unit 3 efficiently in accordance with the discharge state detected by the discharge servo control circuit that controls the servo motor. Then, relative positioning of the workpiece 105 is performed, and electric discharge machining is advanced little by little.

  The power supply device 2 supplies a pulse voltage for electric discharge machining to the wire 103, performs control adapted to a state such as a short circuit generated in the discharge gap, and transmits a discharge gap signal to the discharge servo control circuit.

  The wire electric discharge machining apparatus 1 is connected to the power supply apparatus 2 via the power supply wiring 11, and the wire electric discharge machining apparatus 1 uses the electric power (product of the machining voltage and the machining current) supplied from the power supply apparatus 2 to work 105. EDM.

  The machining fluid supply device 12 feeds machining fluid necessary for cooling a portion where electric discharge occurs and removal of machining waste remaining between the electrodes to the gap between the workpiece 105 and the wire 103 by using a pump. The removal of the processing waste accumulated inside, the management of conductivity (1 μS to 250 μS) by ion exchange, and the management of the liquid temperature (around 20 ° C.) are performed. Although water is mainly used, electric discharge machining oil can also be used.

  The main rollers 8 and 9 are formed with V-grooves having a predetermined pitch so that the workpiece can be sliced with a desired thickness or a predetermined number of pitches so that the workpiece can be sliced with a desired number of pieces. A necessary number of wires from a wire supply bobbin (not shown) are wound around the two main rollers and sent to a take-up bobbin (not shown). The traveling speed of the wire at this time is, for example, about 100 m / min to 900 m / min.

  The two main rollers 8 and 9 rotate in the same direction and at the same speed, so that one wire 103 sent from a wire feeding portion (not shown) becomes the outer periphery of the main roller (two). , And a plurality of wires 103 can be juxtaposed to run in the same direction. The wire 103 is a single connected wire, and is wound around the outer side of the main roller a number of times (up to about 2000 times) spirally while being fed out from the feeding portion and fitted into the V groove on the outer peripheral surface of the main roller. After being wound, it is wound on a winding bobbin.

The main rollers 8 and 9 have a structure in which metal is used for the central shaft and the outside is covered with resin. In the lower part between the main rollers 8.9, a power supply 104 is provided to supply a pulse voltage from the power supply device 2 to the wire, and the power supply 104 is provided with a plurality of wires 103 ( For example, 10) are in contact with each other. Since the power supply 104 is required to be highly resistant to mechanical wear and conductive, a cemented carbide is used.
After the work 105 is attached to the work feeding unit 3 on the main rollers 8 and 9, the work 105 is moved downward to perform electric discharge machining.

  A processing tank 6 is provided in the center portion inside the main rollers 8 and 9, and the wire 103 and the work 105 are immersed in the processing liquid to cool the discharge portion and remove the processing waste.

  A machining power source (not shown) in the power supply device 2 supplies a machining voltage V that is set to supply a machining current necessary for electric discharge machining, and V can be set to an arbitrary voltage. .

  The discharge voltage is a voltage applied between the wire 103 and the workpiece 105 during electric discharge machining, and a portion to which the discharge voltage is applied is a discharge portion. Electric discharge is performed from the wire 103 to the work 105 at the discharge portion. The discharge current is a current that flows between the wire 103 and the workpiece 105 during electric discharge machining.

The power supply 104 supplies power to a plurality of wires 103 that travel. Electric discharge machining is performed by applying a pulse voltage from the power supply 104 arranged at one place in the wire that circulates. One power supply circuit is configured corresponding to one power supply 104.
The current flowing from the power supply 104 to the discharge portion flows from the left and right paths passing through the main rollers 8 and 9, and resistance due to the wire material exists in each path.

  The workpiece feeding unit 3 is a device having a mechanism for moving the workpiece 105 fixed to the holding mechanism 800 in the vertical direction, and the workpiece feeding unit 3 is moved downward (in the direction of gravity) while the workpiece 105 is fixed. The workpiece 105 can be brought closer to the wires 103 arranged side by side by moving in a stepwise manner.

  In the case of the embodiment shown in FIG. 1, the direction in which the juxtaposed wires run is the same as the first direction (upper wire) in which the juxtaposed wires run to the right side, There is a second direction (lower wire) that runs to the left.

  The processing tank 6 is a container for storing a processing liquid. The working fluid is, for example, deionized water having a high resistance value. By the presence of the machining fluid between the wire 103 and the workpiece 105, good electric discharge is generated between the wire 103 and the workpiece 105, and the workpiece 105 can be cut.

The main rollers 8 and 9 are formed with a plurality of rows of V grooves for attaching the wires 103, and the wires 103 are attached to the V grooves. Then, the wire 103 travels when the main rollers 8 and 9 are rotated right or left.
By attaching the wire 103 to the main rollers 8 and 9 in this way, wire rows are formed on the upper and lower sides of the main rollers 8 and 9.

  The wire 103 is an electric conductor, and the supplied pulse voltage is supplied to the wire 103 via the supply electron 104 when the supply electron 104 to which the pulse voltage is supplied from the power supply device 2 and the wire 103 come into contact with each other. . When the electric discharge occurs, the workpiece 105 can be cut and a thin plate-like workpiece (for example, a wafer) can be created. The main component of the material of the wire 103 is iron, and the diameter of the wire is about 0.12 mm (cross-sectional area 0.06 × 0.06 × π mm 2).

  The power supply 104 is fixed to the power supply unit 10. The power supply unit 10 can move the position of the entire power supply unit 10 in the vertical direction in order to adjust the contact pressure between the power supply 104 and the wire 103.

  In the present invention, the workpiece 105 is sent in the downward (gravity) direction, and electric discharge machining is performed between the workpiece 105 and the wire 103. In the present specification, upper and lower correspond to the upper and lower directions in the direction of gravity, and left and right correspond to the left and right when the wire electric discharge machine is viewed from the front.

The block 5 is a part of the housing of the wire electric discharge machining apparatus 1. The block 5 is joined to the work feeding unit 3. The workpiece feeding unit 3 drives the workpiece 105 so as to descend in the direction of gravity, so that the workpiece 105 is sliced into a plate-like workpiece piece 106 by using electric discharge machining using a wire.
FIG. 2 will be described.
3 to 5 show a state after the slicing processing of the workpiece 105 by the wire row is completed and the workpiece 105 is subjected to electric discharge machining into a plurality of workpiece pieces.
FIG. 3 will be described.

  FIG. 3 shows an interface (first interface) between the slice base 300 and the orientation flat part. In this manner, in the interface where the slice base 300 and the orientation flat portion are in contact, an energization region where the workpiece and the slice base 300 are energized and an adhesion region where the workpiece is fixed with an adhesive are provided.

The slice base 300 is processed into a rectangular parallelepiped so as to match the volume of a work held by a conductive material (for example, aluminum), and is also called a slice beam. The slice base 300 is also connected to a DC power supply circuit (not shown) for discharge (not shown), and a machining current flows during electric discharge machining.
In this energization region, an aluminum sheet or a thin bar may be disposed as an energization member.

  As another modification, in order to provide a current-carrying region in the first interface, the plane of the slice base 300 is previously processed into a convex shape, and the conductive member is provided in advance on a part of the plane of the slice base 300. It is also possible to eliminate the trouble of preparing the energization region.

Furthermore, an adhesive that is non-conductive and can be easily peeled off from the slice base 300 by being immersed in hot water of about 80 ° C. may be applied to the surface of the slice base 300.
FIG. 4 will be described.

  As shown in FIG. 4, the adhesive may be applied to the region where the plurality of wire pieces can be bonded even when the slicing is finished so that the work becomes a plurality of work pieces within the first interface. That is, even when slicing is completed so as to form a plurality of work pieces, it is only necessary that the adhesive exists in an area where the slice base 300 can hold a plurality of wire pieces.

By doing so, since the workpiece piece is held only by the slice base between immediately before the completion of cutting and after the completion of cutting, the workpiece piece is held by the curable adhesive. Can be prevented from vibrating even under the influence of the water flow of the machining fluid, so that the electrical discharge machining by the wire row at the end of cutting can be completed in a state where the position of each work piece is fixed. The processing accuracy (width uniformity, etc.) of the wire piece is improved.
FIG. 5 will be described.

  As shown in FIG. 5, the energization region may be provided in the region where the wire array can be discharged in the first interface until slicing is completed so that the workpiece becomes a plurality of workpiece pieces. For this purpose, the energization region needs to exist in an area that intersects all the wire rows. For example, by providing the energization region as shown in FIG. Even if the relative position between the region and the wire row slightly deviates in the direction in which the wire rows are arranged, the wire row can be reliably discharged to the energized region until the completion of slicing.

In order for the current-carrying region to be present in a region that intersects all the wire rows, for example, as shown in FIG. 5, the current-carrying region and the bonding region in the first interface intersect the direction in which the wire row travels. It is preferable that the first interface is provided so as to be arranged in a straight line in the direction (the direction in which they are arranged).
The current-carrying area is made of a conductive material such as aluminum. Since the energized region is intended for energization, it may be composed of another conductive metal material.

As shown in FIG. 3, the energized region must be disposed at a location where the wire can be discharged even after the workpiece 105 has been sliced. The reason for this is that when the slicing of the workpiece 105 is completed, the workpiece 105 becomes a plurality of workpiece pieces 106, as shown in FIG. This is because the only possible location is the upper side of the work piece 106.
Thus, the role of the energization region is to energize all work pieces continuously until the electric discharge machining is completed.
FIG. 6 will be described.

  FIG. 6 shows a side plate (holding member) in which a slice base (conductive member) 300 according to the present invention holds an orientation flat portion (an upper plane of the workpiece 105) of the workpiece 105 with an adhesive and is attached to a side plane of the workpiece 105. ) Shows the state of the holding device that holds the workpiece 105 so that the workpiece 105 before slicing does not fall in the direction of gravity.

  As shown in FIG. 6, at the start of machining, the workpiece 105 starts moving toward the wire 103 based on the lowering operation of the workpiece feeding unit 3. Thereafter, the workpiece 105 is subjected to electric discharge machining by the wire 103, and electric discharge machining is completed at the wire position at the end of cutting shown in FIG.

As shown in FIG. 6, since the slice base 300 descends at a position where it does not interfere with the wire row, the workpiece is held at a place where the electric discharge machining is not performed by the wire row.
FIG. 7 will be described.

FIG. 7 shows an interface (second interface) at which the side plate 812 contacts the side plane of the workpiece 105. In this way, in the interface where the side plate 812 is in contact with the side plane, an energization region in which the workpiece 105 and the side plate 812 are energized and an adhesion region in which the workpiece is fixed with an adhesive are provided.
The side plate 812 can be made of a conductive material such as aluminum or SUS.
Functions provided in the side plate 812 will be described.
Note that the shape of the side plate 812 is not limited to the shape shown in FIG. 7, and may be any shape provided with a surface for holding the workpiece 105 from the side.

  In the example of FIG. 7, a deep groove (concave portion) is processed on the surface of the side plate 812 where the workpiece 105 and the side plate 812 contact each other, the inside of the deep groove is filled with an adhesive, and the workpiece 105 and the side plate 812 are bonded. The side surface of the workpiece can be firmly fixed by the side plate 812 by bonding with an agent. The region filled with the adhesive functions as an adhesive region that holds the workpiece so as not to fall. In order to provide an adhesive region in the second interface, the surface of the side plate 812 may be processed in advance into a concave (groove) shape, and the adhesive region may be provided in advance on a part of the plane of the side plate 812, The trouble of preparing the bonding area can be omitted.

  As the kind of adhesive, it is preferable to use a non-conductive adhesive that is currently mainstream in an abrasive-type wire saw. The reason is that the non-conductive adhesive can be bonded at room temperature, and can be easily peeled off from the workpiece simply by immersing the non-conductive adhesive in hot water of 80 ° C. or higher. However, since it is non-conductive, the work 105 cannot be energized in the region bonded with the non-conductive adhesive. Therefore, a region on the side plate 812 that is not filled with the non-conductive adhesive functions as a current-carrying region where the work 105 can be energized. An epoxy resin or the like is used as the non-conductive adhesive.

  If a conductive adhesive is used, the side plate 812 cannot be easily peeled from the work piece by the above method, and the work piece portion bonded to the side plate 812 cannot be used.

As shown in FIG. 7, the side plate 812 holds the workpiece 105 from the side with a non-conductive adhesive applied to the bonding region, and as shown in FIG. 4 and FIG. Can be held from the side so that the workpiece 105 does not fall vertically until the electric discharge machining is completed.
As described above, the side plate 812 is not on the route that comes into contact with the wire 103 during electric discharge machining, so the wire 103 does not electric discharge machine the side plate 812.
FIG. 8 is a cross-sectional view of the side plate 812, in which deep grooves filled with a non-conductive adhesive are formed.

DESCRIPTION OF SYMBOLS 1 Wire electric discharge machine 2 Power supply device 3 Work feeding unit 103 Wire 104 Electric supply 105 Work 300 Slice base 812 Side board

Claims (7)

A holding device that is used in electric discharge machining to slice a workpiece with wires arranged in parallel, and holds the workpiece when the workpiece is fed in the direction of gravity,
Comprising a conductive member energized with the workpiece;
In the first interface where the conductive member and the upper flat surface of the work are in contact, an energization area where the work and the conductive member are energized and an adhesion area where the work is fixed with an adhesive are provided. And
The energized region is provided in a region in the first interface where the arranged wires can be discharged until slicing is completed so that the workpiece becomes a plurality of workpiece pieces,
The bonding region is provided in a region in the first interface where the plurality of wire pieces can be bonded even when slicing is completed so that the workpiece becomes a plurality of workpiece pieces. Holding device. In a place where the electric discharge machining is not performed by the wires arranged side by side, the holding member holding the workpiece is further provided
In the second interface where the holding member and the side plane of the workpiece are in contact with each other, an energization region for energizing the workpiece and the holding member and an adhesion region for fixing the workpiece with an adhesive are provided. The holding device according to claim 1.   The holding device according to claim 1, wherein the energization region in the first interface has a convex shape and is provided as a part of the conductive member.   The energization region and the adhesion region in the first interface are provided in the first interface so that each of them is arranged in a straight line in a direction intersecting the direction in which the juxtaposed wires travel. The holding device according to any one of claims 1 to 3, wherein the holding device is characterized.   5. The holding device according to claim 1, wherein an adhesive region in the second interface has a concave shape and is provided as a part of the holding member. 6. A wire electrical discharge machining device that slices a plurality of workpiece pieces by feeding the workpiece in the direction of gravity and performing electrical discharge machining of the workpiece with wires arranged in parallel,
Comprising a conductive portion for energizing the workpiece;
In the first interface where the conductive portion and the upper flat surface of the work are in contact, an energization area where the work and the conductive member are energized and an adhesion area where the work is fixed with an adhesive are provided. ,
The energized region is provided in a region in the first interface where the arranged wires can be discharged until slicing is completed so that the workpiece becomes a plurality of workpiece pieces,
The bonding region is provided in a region in the first interface where the plurality of wire pieces can be bonded even when slicing is completed so that the workpiece becomes a plurality of workpiece pieces. Wire electrical discharge machining equipment. In a place where electric discharge machining is not performed by the wires arranged side by side, the holding unit holding the workpiece is further provided,
In the second interface where the holding portion and the side plane of the workpiece are in contact with each other, an energization region for energizing the workpiece and the holding member and an adhesion region for fixing the workpiece with an adhesive are provided. The wire electric discharge machining apparatus according to claim 6.

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