JPH0758705B2 - Reaction product removal device of precision cutting device by radical reaction - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention utilizes a radical (free radical) reaction to, for example, a silicon single crystal for manufacturing a semiconductor device, a germanium single crystal, a gallium-arsenic compound,
Alternatively, the present invention relates to a reaction product removing device in a precision cutting device that is suitable for accurately cutting relatively thick materials such as ceramics and glass that are difficult to cut by a normal mechanical method.

[0002]

2. Description of the Related Art Conventionally, a dicing processing method using a diamond wheel has been employed for cutting a silicon single crystal or the like. However, when cutting by this method, a plastic working layer remains on the surface and fine cracks are generated, which causes the manufacturing process. This causes a decrease in the yield of the processed wafer.

In order to solve such a problem, a precision processing method utilizing a radical reaction has been proposed (JP-A-1-125829). The precision processing method by this radical reaction is to generate a radical by activating the reaction gas by discharge or laser light excitation in the vicinity of the work piece arranged in the atmosphere of the reaction gas, and generating the radical and the constituent atom of the work piece or The object is processed by radical reaction with molecules.

In the above-mentioned publication, as an example of a processing method, a voltage is applied to a wire electrode wound on a wire supply bobbin while the wire electrode is wound on a wire take-up bobbin to apply a voltage to the wire electrode. A discharge is generated between the cut objects to activate the reaction gas, the reaction gas generates radicals to cause a radical reaction between the radicals and the constituent atoms or molecules of the cut object, and the cut object to the wire electrode. There is disclosed a precision cutting method by a radical reaction in which an object to be cut is cut by relatively moving the wire electrode in a direction traversing the wire electrode.

[0005]

However, in the above disclosed technique, if the object to be cut is thin, the radical reaction can be continued and cut by the reaction gas in the chamber. When cutting a thick object with a narrow cutting width, the reaction gas is likely to be insufficiently supplied to the groove bottom of the cutting groove, the reaction product is not removed from the groove bottom, and the radical reaction by plasma does not proceed. There is a risk. Therefore, it is impossible to smoothly cut a thick object to be cut.

An object of the present invention is to provide a reaction product removing device of a precision cutting device by a radical reaction, which can efficiently remove a reaction product from a cutting groove of an object to be cut.

[0007]

In order to achieve the above-mentioned object, the present invention applies a voltage to a wire electrode wound on a wire supplying bobbin while applying the voltage to the wire electrode while the wire electrode is being drawn by a take-up roller. A discharge is generated between the object and the object to be cut to activate the reaction gas, a radical is generated by the reaction gas to cause a radical reaction between the radical and a constituent atom or molecule of the object to be cut, and the object to be cut is a wire electrode. In the precision cutting device by radical reaction that moves the wire electrode in a direction crossing the wire electrode to cut the object to be cut, a suction nozzle is formed next to the object to be cut, and a suction port is formed in the object to be cut. A suction device disposed at the bottom of the cutting groove and movably in the traveling direction of the wire electrode, and a suction device for sucking the reaction gas in the cutting groove through the suction nozzle to the suction nozzle, and cutting movement of the cut object. It has a structure obtained by attaching a moving device for moving the suction nozzle following the displacement of the opening end of the groove bottom portion of the cutting groove with.

[0008]

When the cross-sectional shape of the object to be cut is circular, for example, when the object to be cut is moved by moving it in the direction orthogonal to the traveling direction of the wire electrode, the cutting movement of the object to be cut is accompanied. The opening end of the groove bottom portion of the cutting groove is displaced in the traveling direction of the wire electrode. The moving device moves the suction nozzle following the displacement of the opening end of the groove bottom portion. Therefore,
The suction port of the suction nozzle is always located near the open end of the groove bottom portion of the cutting groove, and the reaction product at the groove bottom is accurately sucked and removed. By removing the reaction product, the supply of the reaction gas to the bottom of the groove is improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The attached drawings show an embodiment of a reaction product removing device of a precision cutting device by radical reaction according to the present invention.
In these drawings, reference numeral 1 is a frame, which has three chambers Ca, Cb, and Cc. First chamber Ca
Is provided with a wire electrode W supply mechanism 2, a central second chamber Cb is provided with a cutting mechanism 3, and a third chamber Cc is provided.
The wire electrode W take-up mechanism 4 is provided therein.

The wire electrode W supply mechanism 2 mainly includes a wire supply bobbin 5 around which the wire electrode W is wound, a dancer roller 6, a brake drum 7, and a positioning roller 8. The wire electrode W of the wire supply bobbin 5 is wound around the dancer roller 6, the brake drum 7, the external roller 10 and the brake drum 7 in this order, and the positioning roller 8
Be drawn to. The wire supply bobbin 5 is detachably attached to the rotary shaft 12 of the anti-phase brake motor 11, and resistance is applied by the anti-phase brake motor 11 to the rotation when the wire electrode W is drawn and supplied.

The dancer roller 6 is attached to the rotary arm 14 of the encoder 13. The encoder 13
The tension of the wire electrode W between the wire supply bobbin 5 and the brake drum 7 is detected from the rotation angle of the rotation arm 14, and the detection signal is output to the antiphase brake motor 11. The antiphase brake motor 11 changes the braking force according to the detection signal of the encoder 13 to keep the tension of the wire electrode W between the wire supply bobbin 5 and the brake drum 7 constant. An electromagnetic brake 15 (FIG. 2) is attached to the brake drum 7 and applies a resistance to the rotation of the brake drum 7.

The cutting mechanism 3 includes a pair of front and rear (left and right in FIG. 1) guide rollers 16, 17, 18, 19 and a power feeding brush 21, which is disposed between the guide rollers 16, 17, 18, 19. 22, a reaction gas supply nozzle 23, and a holding plate 25 that holds an object 24 to be cut. Chamber C
In b, a base 26 is provided by being fixed to a fixing pin 27 which is inserted into the bottom plate 1a from below. An upper and lower member 29 (FIG. 3) is attached to the vertical plate 28 of the base 26 so as to be vertically adjustable by an adjusting screw 30, and
A lateral movement member 31 is attached to the upper and lower members 29 by an adjusting screw 32.
The guide rollers 16, 17, 18 and 19 are mounted so as to be adjustable in the horizontal direction (direction perpendicular to the paper surface in FIG. 1) orthogonal to the direction in which the guide rollers 16, 17, 18 and 19 are arranged. Each guide roller 16,1
7, 18 and 19 have guide grooves on the outer peripheral surface.

Guide rollers 16, 17, 1 of the cutting mechanism 3
Reference numerals 8 and 19 are attached to the lateral movement member 31, horizontally guide the wire electrode W sent from the positioning roller 8 of the supply mechanism 2 into the chamber Cb through the sealing mechanism 34 provided in the partition wall 1b, and others. It is sent out to the chamber Cc through the seal mechanism 35 provided in the partition wall 1c. The power supply brushes 21 and 22 are fixed to a swing member 37 that is swingably attached to the vertical plate 28, and the guide roller 1
The wire electrodes W are in contact with each other in the middle of the rollers 6, 19 and the guide rollers 18, 19. The oscillating member 37 is moved by the brush oscillating motor 38 together with the power feeding brushes 21 and 22 in the horizontal direction intersecting the wire electrode W. The attachment member 36 is adjustable in the length direction of the wire electrode W. The equipment structure of the guide rollers 16 and 17 and the power supply brush 21 is the same as that of the guide rollers 18 and 19 and the power supply brush 22 in FIG.

The reaction gas supply nozzle 23 is a guide roller 1.
It is horizontally attached to the attachment member 36 between the positions 7 and 18. The supply nozzle 23 is formed thinner than the groove width of the cutting groove 24a formed in the cut object 24 by the radical reaction, and has a slit-shaped ejection port at its side edge (lower edge).
The outlet of the supply nozzle 23 is parallel to the wire electrode W between the guide rollers 17 and 18. In addition, the supply nozzle 23
Is connected via a pipe to a cylinder (not shown) of chlorine or fluorine-based reaction gas, and the reaction gas is ejected from the ejection port to the groove bottom 24b of the cutting groove 24a. The supply nozzle 23 is normally configured to eject the reaction gas uniformly from the ejection port over its entire length, but its specific structure is arbitrary.

Further, the holding plate 25 of the object to be cut 24 is moved up and down by a vertical servomotor 40 and a rod 41.
Supported by. The up / down servo motor 40 moves the object to be cut 24 to the rod 41 and the holding plate 25 as the cutting progresses.
Rise vertically through. A bellows 42 is provided at a portion of the bottom plate 1a through which the rod 41 penetrates, and the portion is made airtight.

The wire electrode W take-up mechanism 4 includes guide rollers 43, 44, 45 and 46, a take-up roller 47,
A take-up motor 48 and a pinch roller 49 are main components. The take-up motor 48 rotates the take-up roller 47. The pinch roller 49 is attached to the tip of a lever 51 that is rotatable up and down, and is pressed against the take-up roller 47 by a spring 52.

The central wire electrode W is a guide roller 43,
45, and the wire electrodes W on both sides are connected to the guide rollers 43,
They are guided by 44 and 46, respectively, and are respectively sandwiched between the take-up roller 47 and the pinch roller 49, and the take-up motor 47 rotates to take up from the wire supply bobbin 5 to the take-up roller 47. To be
A roll cutter 53 is provided below the take-up roller 47. The roll cutter 53 cuts the used wire electrode W drawn by the take-up roller 47 into a predetermined length.

Reference numeral 55 is a suction nozzle. The suction nozzle 55 is provided with its suction port 55a under the wire electrode W between the guide rollers 17 and 18, to be precise, at the groove bottom 24b of the cutting groove 24a formed in the workpiece 24.
It penetrates b and 1c and is attached to the support member 57. The support member 57 is the stepping motor 5 for horizontal movement.
It is moved horizontally with the suction nozzle 55 by a ball screw 60 which is rotated at 6. The suction nozzle 55 is connected to a pipe 63 of a suction device 62 via an expansion pipe 61 such as a bellows.
It is connected to the. The expansion tube 61 allows the suction nozzle 55 to move horizontally. As the suction device 62, a vacuum pump, a mechanical booster, a dry pump, a blower, or a combination thereof is used. Suction nozzle 55 and piping 63
A heat retention heater 54 is provided in the. Heat insulation heater 54
Keeps the suction nozzle 55 and the pipe 63 warm, and holds the reaction product such as sulfur in the form of mist or vapor to prevent clogging of the nozzle 55 and the like due to the attachment of the reaction product.

The suction device 62 sucks the reaction products (SiF ₄ , S, C, etc.) generated by the radical reaction and the surplus reaction gas from the groove bottom 24b of the cutting groove 24a through the suction nozzle 55. The suction by the suction device 62 is performed by the central chamber Cb.
The atmospheric pressure inside is slightly lower than the atmospheric pressures of the left and right chambers Ca and Cc so that the reaction gas does not leak out of the chamber Cb. A bellows 58 is provided between each partition wall 1b, 1c and the suction nozzle 55, and the portion is made airtight.
An inspection window 59 is appropriately provided on the outer wall of each chamber Ca, Cb, Cc.
Is provided.

A controller 64 is connected to the stepping motor 56 for horizontal movement. The control device 64 includes a position take-in unit 65, a calculation / control unit 66, and a motor drive unit 6.
7 and 7. The position take-in unit 65 is connected to a control device on the side of the vertical servomotor 40 or a cutting position detecting device 68, and takes in the cutting position of the object 24 to be cut output from the device 68 and sends it to the arithmetic / control unit 66. . The calculation / control unit 66 determines the position of the opening end of the groove bottom 24b portion in the traveling direction of the wire electrode W from the output signal of the position capturing unit 65, and always detects the position of the suction nozzle 55 near the opening end of the groove bottom 24b portion. The stepping motor 56 for horizontal movement is controlled so that the suction port 55a is provided. A horizontal movement stepping motor 56, a ball screw 60, a support member 57,
The control device 64 constitutes a moving device 69 for the suction nozzle 55. In FIG. 5, the moving device 6 for the suction nozzle 55 on the left side is shown.
Although only 9 is shown, the moving device 69 of the suction nozzle 55 on the right is also the same.

In the illustrated embodiment, the supply mechanism 2, the cutting mechanism 3, the take-up mechanism 4 and the like are provided for each of the three sets, and the object 24 to be cut is cut at three points at the same time. The number of sets can be increased or decreased. In addition, the wire feeding bobbin 5, the dancer roller 6, the brake drum 7,
It goes without saying that all the transfer systems of the wire electrodes W such as the seal mechanisms 34 and 35 are insulated. Wire electrode W
Insulation of the transfer system reduces the capacitance as much as possible.
Further, since electromagnetic waves generated in the chamber may cause malfunctions and burnouts of the motors, the motors and the wiring are shielded to prevent electromagnetic waves.

Next, the operation of the reaction product removing device of the precision cutting device according to the present invention having the above-described structure will be described. The take-up motor 48 is driven to rotate to take the wire electrode W wound around the wire supply bobbin 5 to the take-up roller 47, while supplying the reaction gas from the supply nozzle 23 and feeding brush 21. , 22 is applied to the wire electrode W to generate a discharge between the wire electrode W and the object to be cut 24.
The discharge activates the reaction gas to generate radicals,
The radicals react radically with the constituent atoms or molecules of the material to be cleaved. As a result, the groove 24a is formed in the object to be cut 24, and the object to be cut 24 is cut. At the time of power feeding, the brush swinging motor 38 swings the power feeding brushes 21 and 22 in the horizontal direction intersecting the wire electrode W to prevent local abrasion of the power feeding brushes 21 and 22.

As the cutting of the object to be cut 24 progresses, the up-and-down servo motor 40 is operated to raise the object to be cut 24. In addition, the suction device 62 includes the suction nozzle 55 and the groove bottom 24b.
Is sucked in, and the atmospheric pressure of the central chamber Cb is made slightly lower than that of the chambers Ca and Cc. Therefore, the discharge is not stopped by the reaction product, the radical reaction, that is, the cutting is smoothly performed, and the leakage of the reaction gas to the outside is prevented. At this time, the opening end of the groove bottom 24b of the cutting groove 24a is displaced in the traveling direction of the wire electrode W as the object to be cut 24 rises.
In accordance with this displacement, 9 moves the suction nozzles 55, 55 horizontally so that the suction ports 55a of the suction nozzles 55, 55 are always located near the opening end of the groove bottom 24b. Therefore, the reaction product on the groove bottom 24b is accurately sucked and removed, and the reaction gas is satisfactorily supplied to the groove bottom 24b.

The supply nozzle 23 is formed thinner than the cutting groove 24a formed by the radical reaction, and the cutting groove 2 is formed together with the wire electrode W as the object 24 to be cut rises.
Enter in 4a. Therefore, the thickness of the object to be cut 24 is large, and no matter how deep the cutting groove 24a is, the groove bottom 24b
It is possible to sufficiently supply the reaction gas to and to continue the uniform cutting process.

At present, the diameter of a silicon block for manufacturing a semiconductor device, which is cut by a dicing process with a diamond wheel, is generally 6 to 8 inches, and up to this size is the limit of application of the conventional method. However, in the present invention, since the wire electrode W is used, the diameter of 1
It is also possible to cut silicon blocks of 0 inch or more.
Further, when the electrode is fixed by a plate-shaped blade type, there is a risk of heating the electrode by plasma reaction heat and the risk of melting, and the electrode is damaged by the reaction with radicals,
Although there is a problem in durability and the equipment structure of the electrode is complicated and it is not easy to replace it, in the present invention, since the wire electrode W is used and it is constantly renewed by taking it, the above-mentioned problem is solved. It never happens.

When the wire electrode W is pulled out from the wire supply bobbin 5 and supplied to the cutting mechanism 3, the reverse-phase brake motor 11 and the electrode brake 15 work to operate the wire electrode W.
However, since the encoder 13 controls the anti-phase brake motor 11 by the encoder 13,
Even if the winding diameter of the wire electrode W of the wire supplying bobbin 5 is gradually reduced by the supply of the wire electrode W, the tension does not change.

The wire electrode W usually has a thickness of 0.05.
Wires of various materials with diameters of up to 0.3 mm are used. The supply transfer speed of the wire electrode W is determined in consideration of the strength of the wire electrode W and the like. In order to correspond to various wire electrodes W, the rotation speed of the take-up motor 48, the reverse phase brake motor 11
The braking force of the electrode brake 15 is adjustable. The thickness of the reaction gas supply nozzle 23 is usually 0.1.
It is about 5 to 0.3 mm.

[0028]

As described above, the reaction product removing device of the precision cutting device by the radical reaction according to the present invention is
While applying the wire electrode wound on the wire supply bobbin to the take-up roller, a voltage is applied to the wire electrode to generate an electric discharge between the wire electrode and the object to be cut to activate the reaction gas. By a radical reaction in which a radical is generated to cause a radical reaction between the radical and a constituent atom or molecule of the object to be cut, and the object to be cut is moved in a direction crossing the wire electrode with respect to the wire electrode to cut the object to be cut. In the precision cutting device, a suction nozzle is provided beside the object to be cut, the suction port of which is arranged at a groove bottom portion of a cutting groove formed in the object to be cut and which is movable in the traveling direction of the wire electrode. The suction nozzle includes a suction device for sucking the reaction gas in the cutting groove through the suction nozzle, and a suction nozzle that follows the displacement of the opening end at the groove bottom portion of the cutting groove due to the cutting movement of the object to be cut. The movement device for moving is an attached configurations, and can be effectively removed the product of a radical reaction from the cutting groove of the object to be cut.

[Brief description of drawings]

FIG. 1 is a front sectional view showing an embodiment of a reaction product removing device of a precision cutting device by a radical reaction according to the present invention.

FIG. 2 is a plan sectional view.

FIG. 3 is a side sectional view.

FIG. 4 is an external view showing a relationship between a guide roller and a power supply brush.

FIG. 5 is a block diagram of a main part and a control system of a reaction product removing device according to the present invention.

[Explanation of symbols]

 5 wire supply bobbin 24 object to be cut 24a cutting groove 24b groove bottom 47 take-up roller 55 suction nozzle 55a suction port 62 suction device 69 moving device

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masakazu Takahashi 27, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Incorporated company Niigata Iron Works, Material Structures Research Department (72) Kazuhiro Tsuno Shinisoko, Isogo-ku, Yokohama-shi, Kanagawa 27, Machi Incorporated company Niigata Iron Works Material Structure Research Department

Claims (1)

[Claims] 1. A wire electrode wound on a wire supply bobbin is applied to a wire electrode while being drawn by a take-up roller to generate a discharge between the wire electrode and an object to be cut to activate a reactive gas. A radical is generated by the reaction gas to cause a radical reaction between the radical and a constituent atom or molecule of the object to be cut, and the object to be cut is moved in a direction traversing the wire electrode with respect to the wire electrode to remove the object to be cut. In a precision cutting device by radical reaction for cutting, a suction nozzle beside the object to be cut has its suction port arranged at the groove bottom portion of a cutting groove formed in the object to be cut, and in the traveling direction of the wire electrode. The suction nozzle, which is movably provided, follows the displacement of the opening end at the groove bottom portion of the cutting groove due to the cutting movement of the object to be cut through the suction device that sucks the reaction gas in the cutting groove through the suction nozzle. A reaction product removing device for a precision cutting device by radical reaction, characterized in that a moving device for moving the suction nozzle is attached.