JP2022147269A - Cutting device - Google Patents

Abstract

To provide a cutting device capable of preventing a metal from mixing into a working liquid.SOLUTION: A cutting device cutting a workpiece comprises: a chuck table holding the workpiece; a cutting unit equipped with a cutting blade cutting the workpiece held by the chuck table and including a working liquid supply nozzle for supplying the working liquid to the workpiece; and a working liquid supply unit for supplying the working liquid to the working liquid supply nozzle. The working liquid supply unit comprises: a liquid generating unit generating liquid; a branch path supplying the liquid supplied from the liquid generating unit to a working liquid supply path connected to the working liquid supply nozzle and a measurement liquid supply path; a measurement unit measuring the resistivity or conductivity of the liquid supplied to the measurement liquid supply path; and a disposal path through which the liquid whose resistivity or conductivity is measured is discharged.SELECTED DRAWING: Figure 3

Description

The present invention relates to a cutting device for cutting a workpiece.

In the process of manufacturing device chips, a wafer is used in which devices are formed in a plurality of areas partitioned by a plurality of streets (dividing lines) arranged in a grid pattern. A plurality of device chips each having a device is obtained by dividing the wafer along the streets. Device chips are mounted on various electronic devices such as mobile phones and personal computers.

A cutting device is used to divide the wafer. A cutting device includes a chuck table that holds a workpiece, and a cutting unit that cuts the workpiece. The cutting unit has a spindle, and an annular cutting blade for cutting the workpiece is attached to the tip of the spindle. The wafer is cut and divided by holding the wafer on a chuck table and cutting the wafer with a rotating cutting blade.

When cutting a wafer with a cutting blade, a working fluid is supplied to the wafer and the cutting blade (see Patent Document 1). This working fluid cools the wafer and the cutting blade and washes away debris (cutting debris) generated by cutting.

JP 2004-303855 A

2. Description of the Related Art Pure water is often used as a working fluid that is supplied when a workpiece is machined by a cutting device. However, since pure water has a high specific resistance (electrical resistivity), if pure water is supplied to the workpiece and cutting blade during cutting, the contact area between the cutting blade rotating at high speed and the workpiece will Static electricity is easily generated. As a result, the devices formed on the workpiece may be electrostatically damaged, and the yield of device chips may be reduced.

Therefore, pure water mixed with carbon dioxide (carbonated water) is sometimes used as the working fluid. Since carbonated water has a lower specific resistance than pure water, it does not easily generate static electricity even if it is supplied to the workpiece and the cutting blade during cutting. This suppresses electrostatic breakdown of the device.

When carbonated water is used as the working fluid, the specific resistance value of the working fluid can be controlled by adjusting the amount of carbon dioxide added to the pure water. For example, a resistivity measuring device that measures the resistivity of the liquid is installed in the working fluid supply path that supplies the working fluid to the cutting unit. Then, the resistivity of the machining fluid flowing through the machining fluid supply path is measured by a resistivity measuring device, and the amount of carbon dioxide added to the pure water is adjusted based on the measurement result. Thereby, the value of the specific resistance of the working fluid is fed back, and the value of the specific resistance of the working fluid supplied to the cutting unit is maintained within a desired range.

However, a metal such as copper is used for the measuring needle of the resistivity measuring device. Therefore, when the resistivity of the machining fluid flowing through the machining fluid supply path is measured by a resistivity measuring device, the machining fluid supplied to the cutting unit contains metal. As a result, the machining liquid containing metal is supplied to the workpiece, which may cause problems such as contamination of the workpiece and malfunction of the device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cutting apparatus capable of preventing metal from entering a machining fluid.

According to one aspect of the present invention, there is provided a cutting device for cutting a workpiece, which includes a chuck table for holding the workpiece and a cutting blade for cutting the workpiece held by the chuck table. a cutting unit including a machining fluid supply nozzle that supplies machining fluid to the workpiece; and a machining fluid supply unit that supplies the machining fluid to the machining fluid supply nozzle, the machining fluid supply unit comprising: a liquid generation unit that generates a liquid; a branch path that supplies the liquid supplied from the liquid generation unit to a machining liquid supply path connected to the machining liquid supply nozzle; a measurement liquid supply path; A cutting device comprising a measuring unit for measuring the resistivity or conductivity of the liquid supplied to the liquid supply channel, and a waste channel through which the liquid whose resistivity or conductivity is measured by the measuring unit is discharged provided.

Preferably, the liquid generation unit includes a pure water supply source that supplies pure water, a carbon dioxide supply source that supplies carbon dioxide, pure water supplied from the pure water supply source, and the carbon dioxide supply source. A mixing section for mixing with carbon dioxide supplied from a source, and a carbon dioxide supply valve for adjusting the amount of carbon dioxide supplied to the mixing section from the carbon dioxide supply source.

Also, preferably, the amount of the liquid supplied to the measuring liquid supply path is smaller than the amount of the liquid supplied to the machining liquid supply path. Moreover, preferably, the working liquid supply unit further includes a measurement liquid supply valve for adjusting the amount of the liquid supplied from the branch passage to the measurement unit. Moreover, preferably, the cutting device further includes a branch passage for supplying the liquid supplied from the branch passage to the machining liquid supply passage and the cleaning liquid supply passage.

In the cutting apparatus according to one aspect of the present invention, the liquid supplied from the liquid generation unit is branched and supplied to the machining liquid supply path and the measurement liquid supply path. Then, the liquid supplied from the measurement liquid supply path to the measurement unit and whose specific resistance or conductivity has been measured is discharged to the disposal path. As a result, it is possible to prevent the metal from being mixed into the machining fluid supplied to the workpiece.

It is a perspective view which shows a cutting device. FIG. 2(A) is a perspective view showing the cutting unit, and FIG. 2(B) is a perspective view showing the cutting unit to which the blade cover is attached. 4 is a block diagram showing a working fluid supply unit; FIG. FIG. 3 is a block diagram showing a machining liquid supply unit having a measurement liquid supply valve; FIG. 4 is a block diagram showing a working fluid supply unit to which a branch path is connected;

Hereinafter, this embodiment will be described with reference to the accompanying drawings. First, a configuration example of a cutting device according to this embodiment will be described. FIG. 1 is a perspective view showing a cutting device 2. FIG. In FIG. 1, the X-axis direction (processing feed direction, left-right direction, first horizontal direction) and the Y-axis direction (indexing feed direction, front-rear direction, second horizontal direction) are perpendicular to each other. Also, the Z-axis direction (vertical direction, vertical direction, height direction) is a direction perpendicular to the X-axis direction and the Y-axis direction.

The cutting device 2 includes a base 4 that supports and accommodates each component constituting the cutting device 2 . An opening 4a is formed at the corner of the front end of the base 4, and a cassette support 6 is provided inside the opening 4a to move (elevate) along the Z-axis direction by means of an elevating mechanism (not shown). It is A cassette 8 capable of accommodating a plurality of workpieces 11 to be machined by the cutting device 2 is mounted on the cassette support base 6 . In FIG. 1, the contour of the cassette 8 is indicated by a chain double-dashed line.

For example, the workpiece 11 is a disk-shaped wafer made of a semiconductor material such as silicon, and has a front surface and a back surface that are substantially parallel to each other. The workpiece 11 is partitioned into a plurality of rectangular regions by a plurality of streets (planned division lines) arranged in a lattice so as to intersect each other. Devices such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices are formed on the surface side of the regions partitioned by the streets. there is A plurality of device chips each having a device are manufactured by cutting and dividing the workpiece 11 along the streets by the cutting device 2 .

However, the material, shape, structure, size, etc. of the workpiece 11 are not limited. For example, the workpiece 11 is a wafer (substrate) made of a semiconductor other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass (quartz glass, borosilicate glass, etc.), resin, ceramics, metal, or the like. good too. Moreover, there are no restrictions on the type, number, shape, structure, size, arrangement, etc. of the device, and the device may not be formed on the workpiece 11 .

When the workpiece 11 is processed by the cutting device 2, the workpiece 11 is supported by an annular frame 13 made of metal such as SUS (stainless steel). A circular opening penetrating through the frame 13 in the thickness direction is provided in the central portion of the frame 13 . The diameter of the opening of frame 13 is larger than the diameter of workpiece 11 , and workpiece 11 is placed inside the opening of frame 13 .

A tape 15 is attached to the workpiece 11 and the frame 13 . The tape 15 includes a circular film-like base material and an adhesive layer (glue layer) provided on the base material. For example, the base material is made of resin such as polyolefin, polyvinyl chloride, polyethylene terephthalate. Also, the adhesive layer is made of an epoxy-based, acrylic-based, or rubber-based adhesive or the like. Note that the adhesive layer may be an ultraviolet curable resin that is cured by irradiation with ultraviolet rays.

When the central portion of the tape 15 is attached to the back (lower surface) side of the workpiece 11 and the outer peripheral portion of the tape 15 is attached to the frame 13, the workpiece 11 is supported by the frame 13 via the tape 15. . The workpiece 11 is accommodated in the cassette 8 while being supported by the frame 13 .

A transport unit (transport mechanism) 10 for transporting the workpiece 11 is provided behind the opening 4a. The transport unit 10 is configured to be movable along the Y-axis direction, and unloads the workpiece 11 from the cassette 8 and loads the workpiece 11 into the cassette 8 . A gripping portion 10a for gripping the frame 13 is provided at the end of the transport unit 10 on the side of the opening 4a (the side of the cassette 8).

A temporary placement area 12 is provided between the opening 4 a and the transport unit 10 to temporarily place the workpiece 11 unloaded from the cassette 8 or the workpiece 11 to be loaded into the cassette 8 . A pair of guide rails 14 arranged substantially parallel to each other along the Y-axis direction is provided in the temporary placement area 12 . The pair of guide rails 14 move toward and away from each other along the X-axis direction, sandwiching the frame 13 and aligning the workpiece 11 .

A transport unit (transport mechanism) 16 that transports the workpiece 11 is provided near the temporary placement area 12 . For example, the transport unit 16 includes a plurality of suction pads that suction-hold the top surface of the frame 13 .

On the side of the opening 4a, there is provided a rectangular opening 4b whose longitudinal direction is along the X-axis direction. A moving unit (moving mechanism) 18 having a plate-like moving table 18a is provided inside the opening 4b. The moving unit 18 is, for example, a ball screw type moving mechanism, and moves the moving table 18a along the X-axis direction. On both sides of the moving table 18a, bellows-shaped dust and splash proof covers 20 that expand and contract along the X-axis direction are provided so as to cover the components of the moving unit 18. As shown in FIG.

A chuck table (holding table) 22 for holding the workpiece 11 is provided on the moving table 18a. The upper surface of the chuck table 22 is a flat surface substantially parallel to the horizontal direction (XY plane direction), and constitutes a holding surface 22a that holds the workpiece 11 . The holding surface 22a is connected to a suction source (not shown) such as an ejector through a channel (not shown) provided inside the chuck table 22, a valve (not shown), and the like. A plurality of clamps 24 for holding and fixing the frame 13 are provided around the chuck table 22 .

The moving unit 18 moves the chuck table 22 along the X-axis direction together with the moving table 18a. The chuck table 22 is positioned by the moving unit 18 in a transfer area A where the workpiece 11 is transferred and a machining area B where the workpiece 11 is machined. A rotary drive source (not shown) such as a motor is connected to the chuck table 22, and this rotary drive source rotates the chuck table 22 around a rotary shaft substantially parallel to the Z-axis direction.

The machining area B is provided with a cutting unit 26 for cutting the workpiece 11 . An annular cutting blade 28 is attached to the cutting unit 26 . The cutting unit 26 cuts the workpiece 11 by rotating the cutting blade 28 to cut into the workpiece 11 .

A moving unit (moving mechanism, not shown) that moves the cutting unit 26 along the Y-axis direction and the Z-axis direction is connected to the cutting unit 26 . For example, the movement unit is a ball-screw movement mechanism including a Y-axis ball screw arranged along the Y-axis direction and a Z-axis ball screw arranged along the Z-axis direction. This movement unit adjusts the position of the cutting blade 28 attached to the cutting unit 26 in the Y-axis direction and the Z-axis direction.

An imaging unit 30 that captures an image of the workpiece 11 held by the chuck table 22 is provided at a position that overlaps with the movement path of the chuck table 22 (between the transport area A and the processing area B). For example, the imaging unit 30 includes a visible light camera having an imaging element that receives visible light and converts it into an electric signal, or an infrared camera that has an imaging element that receives infrared light and converts it into an electric signal. The image acquired by the imaging unit 30 is used for alignment between the workpiece 11 and the cutting unit 26, and the like.

A cleaning unit (cleaning mechanism) 32 for cleaning the workpiece 11 is provided behind the chuck table 22 . For example, the cleaning unit 32 includes a spinner table that holds and rotates the workpiece 11, and a cleaning nozzle that supplies cleaning liquid (cleaning liquid) toward the workpiece 11 held by the spinner table.

A transport unit (transport mechanism) 34 that transports the workpiece 11 between the chuck table 22 and the cleaning unit 32 is provided above the cleaning unit 32 . For example, the transport unit 34 includes a plurality of suction pads that suction-hold the upper surface of the frame 13 .

A support base 36 is provided behind the processing area B, and a display unit (display section, display device) 38 is mounted on the support base 36 . Further, an input unit (input unit, input device) 40 for inputting various information to the cutting device 2 is provided at the front end of the base 4 .

Various displays are used as the display unit 38 . Also, as the input unit 40, an operation panel having a plurality of operation keys, a mouse, a keyboard, or the like is used. Note that the cutting device 2 may include a touch panel that functions as a user interface. In this case, the touch panel functions as the display unit 38 and the input unit 40 . The operator can input information to the cutting device 2 by touching the touch panel.

Components constituting the cutting device 2 (cassette support 6, transfer unit 10, guide rail 14, transfer unit 16, transfer unit 18, chuck table 22, clamp 24, cutting unit 26, imaging unit 30, cleaning unit 32, The transport unit 34 , display unit 38 , input unit 40 , etc.) are each connected to a control unit (control section, control device) 42 . The control unit 42 controls the operation of the cutting device 2 by generating control signals that control the operation of each component of the cutting device 2 .

For example, the control unit 42 is configured by a computer. Specifically, the control unit 42 includes a calculation section that performs calculations required for operation of the cutting device 2 and a storage section that stores various information (data, programs, etc.) used for calculations in the calculation section. The calculation unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory) functioning as a main storage device and an auxiliary storage device.

A workpiece 11 is machined by the cutting device 2 described above. Specifically, first, the transport unit 10 moves toward the cassette 8, and grips the end portion of the frame 13 accommodated in the cassette 8 with the grip portion 10a. After that, the transport unit 10 moves away from the cassette 8 along the Y-axis direction. Thereby, the workpiece 11 is pulled out from the cassette 8 and placed on the pair of guide rails 14 .

The pair of guide rails 14 approach each other while supporting the frame 13 from below to sandwich the frame 13 therebetween. As a result, the workpiece 11 is aligned. After that, the workpiece 11 is sucked and held by the transport unit 16 and transported to the chuck table 22 positioned in the transport area A. As shown in FIG.

The workpiece 11 is placed on the holding surface 22a of the chuck table 22 with the tape 15 interposed therebetween. Also, the frame 13 is fixed by a plurality of clamps 24 . In this state, when the suction force (negative pressure) of the suction source is applied to the holding surface 22a, the workpiece 11 is suction-held by the chuck table 22 via the tape 15. As shown in FIG. Then, the chuck table 22 holding the workpiece 11 is positioned in the machining area B by the moving unit 18 .

Next, the workpiece 11 is cut by the cutting blade 28 attached to the cutting unit 26 . For example, with the lower end of the cutting blade 28 positioned below the upper surface of the workpiece 11, the chuck table 22 is moved along the X-axis direction while rotating the cutting blade 28 (processing feed). As a result, the chuck table 22 and the cutting unit 26 move relative to each other along the X-axis direction, and the rotating cutting blade 28 cuts into the workpiece 11 . As a result, the workpiece 11 is linearly cut.

When the processing of the workpiece 11 is completed, the workpiece 11 is transported from the chuck table 22 to the cleaning unit 32 by the transport unit 34 and is cleaned by the cleaning unit 32 . After the cleaned workpiece 11 is conveyed onto the pair of guide rails 14 by the conveying unit 16 , it is held by the grasping portion 10 a of the conveying unit 10 and accommodated in the cassette 8 .

FIG. 2A is a perspective view showing the cutting unit 26. FIG. The cutting unit 26 includes a hollow cylindrical housing 50 . The housing 50 accommodates a cylindrical spindle 52 arranged along the Y-axis direction. A tip portion (one end side) of the spindle 52 is exposed from the housing 50 . A rotation drive source (not shown) such as a motor for rotating the spindle 52 is connected to the base end (the other end) of the spindle 52 .

A mount 54 that supports the cutting blade 28 is fixed to the tip of the spindle 52 . The mount 54 includes a disk-shaped flange portion 56 and a cylindrical support shaft (boss portion) 58 protruding from the central portion of the surface 56 a of the flange portion 56 . An annular convex portion 56 b protruding from the surface 56 a is provided along the outer peripheral edge of the flange portion 56 on the surface 56 a side of the outer peripheral portion of the flange portion 56 . A tip end surface of the convex portion 56b is formed substantially parallel to the surface 56a. A threaded portion 58 a is formed on the outer peripheral surface of the support shaft 58 .

An annular cutting blade 28 for cutting the workpiece 11 is attached to the mount 54 . The cutting blade 28 includes an annular base 28a made of metal such as an aluminum alloy, and an annular cutting edge 28b formed along the outer edge of the base 28a. A cylindrical opening 28c is provided in the central portion of the cutting blade 28 so as to pass through the cutting blade 28 in the thickness direction.

The cutting edge 28b is formed to protrude radially outward from the base 28a from the outer peripheral edge of the base 28a. For example, the cutting edge 28b is formed by fixing abrasive grains made of diamond, cubic boron nitride (cBN) or the like with a binder such as a nickel plating layer. The material of the abrasive grains, the grain size of the abrasive grains, the material of the binder, etc. are not limited, and are appropriately selected according to the material of the workpiece 11 and the like.

An annular fixing nut 60 for fixing the cutting blade 28 is fastened to the threaded portion 58 a of the support shaft 58 . A central portion of the fixing nut 60 is provided with a cylindrical opening 60a penetrating through the fixing nut 60 in the thickness direction. A thread groove corresponding to the threaded portion 58a of the support shaft 58 is formed on the inner peripheral surface of the fixing nut 60 exposed inside the opening 60a.

The cutting blade 28 is attached to the mount 54 so that the support shaft 58 is inserted into the opening 28c. In this state, when the fixing nut 60 is screwed onto the threaded portion 58a of the support shaft 58 and tightened, the cutting blade 28 is held between the tip surface of the projection 56b of the flange portion 56 and the fixing nut 60, and the tip of the spindle 52 is held. portion (mount 54). The cutting blade 28 rotates about a rotation axis substantially parallel to the Y-axis direction by power transmitted from the rotation drive source via the spindle 52 and the mount 54 .

FIG. 2B is a perspective view showing the cutting unit 26 with the blade cover 62 attached. The cutting blade 28 attached to the cutting unit 26 is covered by a box-shaped blade cover 62 fixed to the housing 50 . The blade cover 62 includes a pair of connection portions 64 to which machining fluid is supplied, and a pair of machining fluid supply nozzles 66 connected to the connection portions 64 and arranged to sandwich the lower end portion of the cutting blade 28 . A supply port (not shown) opening toward the cutting blade 28 is formed in each of the pair of machining fluid supply nozzles 66 .

A machining fluid supply path 68 is connected to the cutting unit 26 . One end side of the machining liquid supply path 68 is connected to a machining liquid supply unit 70 that supplies the machining liquid, and the other end side of the machining liquid supply path 68 is connected to a pair of connection portions 64 .

During cutting of the workpiece 11 , machining fluid is supplied from the machining fluid supply unit 70 to the connection portion 64 through the machining fluid supply path 68 . The machining fluid flows into the machining fluid supply nozzle 66 from the connecting portion 64 , and the machining fluid is supplied from the supply port of the machining fluid supply nozzle 66 toward the front surface and the back surface of the cutting blade 28 . The machining fluid cools the workpiece 11 and the cutting blade 28 and washes away scraps (machining scraps) generated by the cutting process.

FIG. 3 is a block diagram showing the working fluid supply unit 70. As shown in FIG. The machining fluid supply unit 70 generates machining fluid and supplies it to the machining fluid supply path 68 . Specifically, the working liquid supply unit 70 includes a liquid generation unit 72 that generates the liquid used as the working liquid.

The liquid generation unit 72 includes a pure water supply source (pure water supply unit) 74 that supplies pure water and a carbon dioxide supply source (carbon dioxide supply unit) 76 that supplies carbon dioxide. The liquid generation unit 72 also includes a mixing section 78 that mixes the pure water supplied from the pure water supply source 74 and the carbon dioxide supplied from the carbon dioxide supply source 76 . A pure water supply source 74 is connected to a mixing section 78 via a pure water supply line 80 , and a carbon dioxide supply source 76 is connected to the mixing section 78 via a carbon dioxide supply line 82 .

For example, the pure water supply source 74 includes a tank storing pure water and a pump for sending the pure water stored in the tank to the pure water supply line 80 , and supplies the pure water to the pure water supply line 80 . Also, for example, the carbon dioxide supply source 76 includes a cylinder filled with carbon dioxide, and supplies the carbon dioxide to the carbon dioxide supply path 82 .

A carbon dioxide supply valve 84 is provided between the carbon dioxide supply source 76 and the mixing section 78 to adjust the amount of carbon dioxide supplied from the carbon dioxide supply source 76 to the mixing section 78 . The carbon dioxide supply valve 84 is connected to the carbon dioxide supply path 82 , and the amount of carbon dioxide supplied to the mixing section 78 is controlled by the opening/closing time or degree of opening of the carbon dioxide supply valve 84 .

The pure water supplied to the pure water supply channel 80 and the carbon dioxide supplied to the carbon dioxide supply channel 82 are joined and mixed in the mixing section 78 . As a result, pure water (carbonated water) mixed with carbon dioxide is produced. The liquid (mixed liquid) generated in the mixing section 78 is supplied to the mixed liquid supply path 86 .

The pure water supply path 80, the carbon dioxide supply path 82, and the mixed liquid supply path 86 are fluid flow paths configured by pipes such as tubes and pipes. For example, the mixing section 78 is configured by joints (joint joints) connected to the pure water supply channel 80 , the carbon dioxide supply channel 82 , and the liquid mixture supply channel 86 . Alternatively, the mixing section 78 may be formed by connecting the pure water supply path 80, the carbon dioxide supply path 82, and the liquid mixture supply path 86 to each other by welding or the like.

The mixed liquid produced by the mixing section 78 is supplied to the branched channel (first branched channel) 88 via the mixed liquid supply channel 86 . The branch channel 88 branches the mixed liquid supplied from the mixed liquid supply channel 86 and supplies it to the machining liquid supply channel 68 and the measurement liquid supply channel 90 .

The machining liquid supply path 68 and the measurement liquid supply path 90 are fluid flow paths configured by piping such as tubes and pipes. Further, for example, the branch channel 88 is configured by joints (branch joints) connected to the working liquid supply channel 68 , the mixed liquid supply channel 86 , and the measurement liquid supply channel 90 . The branch channel 88 may be formed by connecting the machining liquid supply channel 68, the mixed liquid supply channel 86, and the measurement liquid supply channel 90 to each other by welding or the like.

The liquid (working fluid) supplied from the branch channel 88 to the machining fluid supply channel 68 is supplied to the machining fluid supply nozzle 66 (see FIG. 2B) of the cutting unit 26 and used as the machining fluid. The liquid supplied to the machining fluid supply path 68 is pure water (carbonated water) mixed with carbon dioxide, and carbonated water has a lower specific resistance than pure water. Therefore, when carbonated water is used as the machining fluid, static electricity is less likely to occur during machining of the workpiece 11 by the cutting blade 28 . As a result, electrostatic breakdown of devices formed on the workpiece 11 is suppressed.

The liquid (measurement liquid) supplied from the branch path 88 to the measurement liquid supply path 90 is supplied to a measurement unit 92 that measures the specific resistance (electrical resistivity) or electrical conductivity (electrical conductivity) of the liquid. For example, the measurement unit 92 includes a measuring device such as a resistivity measuring device for measuring the specific resistance of the liquid and a conductivity measuring device for measuring the conductivity of the liquid. The measuring device includes a measuring needle made of metal such as copper and immersed in the liquid to be measured.

By immersing the measuring needle of the measuring unit 92 (measuring device) in the liquid supplied to the measuring liquid supply path 90, the specific resistance or conductivity of the liquid is measured. Note that the measurement unit 92 may include a storage section (container or the like) that temporarily stores the liquid supplied from the measurement liquid supply path 90 . In this case, the measuring needle of the measuring unit 92 is immersed in the liquid stored in the storage section.

The total amount of liquid supplied from the mixing section 78 to the branch channel 88 corresponds to the sum of the amount of machining liquid supplied to the machining liquid supply channel 68 and the amount of measurement liquid supplied to the measurement liquid supply channel 90 . Therefore, by controlling the amount of the measurement liquid flowing through the measurement liquid supply path 90, the ratio between the amount of the machining liquid supplied to the machining liquid supply path 68 and the amount of the measurement liquid supplied to the measurement liquid supply path 90 can be adjusted. can be adjusted. For example, the amount of measurement liquid flowing through the measurement liquid supply path 90 can be adjusted by the structure and dimensions of the joint used as the branch path 88, the inner diameter of the measurement liquid supply path 90, and the like.

The values (resistivity value, conductivity value, etc.) measured by the measurement unit 92 are output to the control unit 42 . Then, the control unit 42 outputs a control signal to the carbon dioxide supply valve 84 according to the measured value, and controls the opening/closing time or opening degree of the carbon dioxide supply valve 84 . Thereby, the amount of carbon dioxide supplied to the mixing section 78 is adjusted, and the specific resistance and conductivity of the mixed liquid supplied from the mixing section 78 to the mixed liquid supply path 86 are controlled.

For example, when the measurement unit 92 measures the resistivity of the liquid to be measured, reference values (upper limit and lower limit) that define the allowable range of the resistivity of the mixed liquid are stored in the storage section (memory) of the control unit 42. is stored. Then, the control unit 42 compares the measured value input from the measuring unit 92 with the reference value stored in the storage unit to determine whether the specific resistance value of the mixed liquid is within the allowable range. judge.

If the measured value exceeds the upper limit of the allowable range, the control unit 42 outputs a control signal to the carbon dioxide supply valve 84 to increase the opening time or degree of the carbon dioxide supply valve 84 . As a result, the amount of carbon dioxide supplied to the mixing section 78 increases, and the specific resistance of the liquid mixture decreases. On the other hand, if the measured value is below the lower limit of the allowable range, the control unit 42 outputs a control signal to the carbon dioxide supply valve 84 to decrease the opening time or degree of the carbon dioxide supply valve 84 . This reduces the amount of carbon dioxide supplied to the mixing section 78 and increases the specific resistance of the liquid mixture.

On the other hand, when the conductivity of the mixed liquid is measured by the measurement unit 92, reference values (upper limit and lower limit) that define the allowable range of the conductivity of the mixed liquid are stored in the storage section (memory) of the control unit 42. is stored. Then, the control unit 42 compares the measured value input from the measurement unit 92 with the reference value stored in the storage unit to determine whether the conductivity value of the mixed liquid is within the allowable range. judge.

If the measured value exceeds the upper limit of the allowable range, the control unit 42 outputs a control signal to the carbon dioxide supply valve 84 to decrease the opening time or degree of the carbon dioxide supply valve 84 . As a result, the amount of carbon dioxide supplied to the mixing section 78 is reduced, and the conductivity of the liquid mixture is lowered. On the other hand, if the measured value is below the lower limit of the allowable range, the control unit 42 outputs a control signal to the carbon dioxide supply valve 84 to increase the opening time or degree of the carbon dioxide supply valve 84 . As a result, the amount of carbon dioxide supplied to the mixing section 78 increases, and the conductivity of the liquid mixture increases.

Here, the measurement needle of the measurement unit 92 (measuring device) is immersed in the liquid (measurement liquid) whose resistivity or conductivity is to be measured by the measurement unit 92, as described above. At this time, metal such as copper constituting the measuring needle is mixed in the measuring liquid. Therefore, if the measurement liquid to be measured by the measurement unit 92 is used as the working liquid, the working liquid containing metal may be supplied to the work piece 11 and the work piece 11 may be contaminated. .

Therefore, in the present embodiment, the liquid whose specific resistance or conductivity has been measured by the measurement unit 92 is discarded without being used as the working liquid. Specifically, the measurement unit 92 is connected to a waste channel (waste liquid channel) 94 configured by piping such as a tube and a pipe. Then, the liquid whose specific resistance or conductivity is measured by the measuring unit 92 is supplied to the disposal path 94 and discharged to the outside of the machining liquid supply unit 70 . As a result, the metal-containing measurement liquid is not supplied to the workpiece 11, and contamination of the workpiece 11 is avoided.

The amount of liquid supplied from the branch channel 88 to the measuring liquid supply channel 90 is preferably smaller than the amount of liquid supplied from the branch channel 88 to the working liquid supply channel 68 . As a result, the amount of waste measurement fluid can be reduced, and the amount of machining fluid supplied to the machining fluid supply nozzle 66 (see FIG. 2B) of the cutting unit 26 can be increased. Specifically, the amount of liquid supplied to the measurement liquid supply path 90 is set to 30% or less, preferably 20% or less, more preferably 10% or less of the amount of liquid supplied to the machining liquid supply path 68. be done.

For example, when the flow rate of the liquid supplied to the machining liquid supply path 68 is set to 10 L/min or more and 15 L/min or less, the flow rate of the liquid supplied to the measurement liquid supply path 90 can be set to 3 L/min or less. However, the amount of liquid supplied to the measurement liquid supply path 90 can be changed as appropriate. By setting the amount of the liquid supplied to the measurement liquid supply path 90 to the minimum amount required for the measurement of the specific resistance or conductivity by the measurement unit 92, the liquid supplied to the machining liquid supply path 68 can maximize the amount of

As described above, in the cutting device 2 according to the present embodiment, the liquid supplied from the liquid generation unit 72 is branched and supplied to the machining liquid supply path 68 and the measurement liquid supply path 90 . Then, the liquid supplied from the measurement liquid supply path 90 to the measurement unit 92 and whose specific resistance or conductivity has been measured is discharged to the disposal path 94 . As a result, it is possible to prevent metal from being mixed into the machining fluid supplied to the workpiece 11, and contamination of the workpiece 11 is avoided.

The configuration of the machining liquid supply unit 70 can be changed as appropriate as long as the measurement liquid containing metal is not supplied to the workpiece 11 . For example, the machining liquid supply unit 70 may include a measurement liquid supply valve that adjusts the amount of liquid supplied to the measurement unit 92 .

FIG. 4 is a block diagram showing the machining liquid supply unit 70 having the measurement liquid supply valve 96. As shown in FIG. As shown in FIG. 4 , a measurement liquid supply valve 96 may be provided between the branch path 88 and the measurement unit 92 to adjust the amount of liquid supplied from the branch path 88 to the measurement unit 92 . The measurement liquid supply valve 96 is connected to the measurement liquid supply path 90 , and the amount of liquid supplied to the measurement unit 92 is controlled by the opening/closing time or opening degree of the measurement liquid supply valve 96 . The opening and closing of the measurement liquid supply valve 96 is controlled by a control signal input from the control unit 42 .

By providing the measurement liquid supply valve 96 , it becomes possible to freely control the amount of liquid supplied from the branch passage 88 to the measurement unit 92 . As a result, the ratio between the amount of the machining liquid supplied to the machining liquid supply path 68 and the amount of the measurement liquid supplied to the measurement liquid supply path 90 can be easily and strictly controlled. Further, during a period in which the measurement of the specific resistance or conductivity of the measurement liquid is not performed, by closing the measurement liquid supply valve 96, all of the mixed liquid generated in the mixing section 78 is supplied to the machining liquid supply path 68 as the machining liquid. can do.

Also, the liquid supplied from the working liquid supply unit 70 can be used for purposes other than the working liquid. For example, the liquid supplied from the machining liquid supply unit 70 can also be used as the cleaning liquid.

FIG. 5 is a block diagram showing the working fluid supply unit 70 to which the branch path (second branch path) 100 is connected. Branch 100 is connected to branch 88 via flow path 98 . The branch path 100 branches the liquid supplied from the branch path 88 through the flow path 98 and supplies the liquid to the machining liquid supply path 68 and the cleaning liquid supply path 102 . A specific configuration example of the fork 100 is similar to that of the fork 88 . Also, the flow path 98 and the cleaning liquid supply path 102 are configured by piping such as tubes and pipes.

The cleaning liquid supply path 102 is connected to the cleaning unit 32 (see FIG. 1) of the cutting device 2 . The liquid supplied from the branch channel 100 to the cleaning liquid supply channel 102 is supplied to the cleaning nozzle provided in the cleaning unit 32 . As a result, the workpiece 11 can be washed using carbonated water with high washing ability as the washing liquid. The cleaning liquid supply path 102 may be provided with a cleaning liquid supply valve for adjusting the amount of liquid (cleaning liquid) supplied from the branch path 100 to the cleaning unit 32 .

In addition, the structure, method, and the like according to the present embodiment can be changed as appropriate without departing from the scope of the purpose of the present invention.

REFERENCE SIGNS LIST 11 workpiece 13 frame 15 tape 2 cutting device 4 base 4a, 4b opening 6 cassette support 8 cassette 10 transport unit (transport mechanism)
10a Gripper 12 Temporary placement area 14 Guide rail 16 Transport unit (transport mechanism)
18 mobile unit (moving mechanism)
18a moving table 20 dust and drip proof cover 22 chuck table (holding table)
22a holding surface 24 clamp 26 cutting unit 28 cutting blade 28a base 28b cutting edge 28c opening 28c opening 30 imaging unit 32 cleaning unit (cleaning mechanism)
34 transport unit (transport mechanism)
36 support base 38 display unit (display section, display device)
40 input unit (input unit, input device)
42 control unit (control unit, control device)
50 housing 52 spindle 54 mount 56 flange 56a surface 56b projection 58 support shaft (boss)
58a screw portion 60 fixing nut 60a opening 62 blade cover 64 connecting portion 66 machining fluid supply nozzle 68 machining fluid supply path 70 machining fluid supply unit 72 liquid generation unit 74 pure water supply source (pure water supply unit)
76 carbon dioxide source (carbon dioxide supply unit)
78 mixing section 80 pure water supply path 82 carbon dioxide supply path 84 carbon dioxide supply valve 86 mixed liquid supply path 88 branched path (first branched path)
90 measurement liquid supply path 92 measurement unit 94 disposal path (waste liquid path)
96 measurement liquid supply valve 98 flow path 100 branch path (second branch path)
102 cleaning liquid supply path

Claims (5)

A cutting device for cutting a workpiece,
a chuck table that holds the workpiece;
a cutting unit equipped with a cutting blade for cutting the workpiece held by the chuck table and having a machining fluid supply nozzle for supplying machining fluid to the workpiece;
a machining liquid supply unit that supplies the machining liquid to the machining liquid supply nozzle;
The working fluid supply unit is
a liquid generation unit for generating a liquid;
a branch path for supplying the liquid supplied from the liquid generation unit to the working liquid supply path connected to the working liquid supply nozzle and the measurement liquid supply path;
a measurement unit for measuring the specific resistance or conductivity of the liquid supplied to the measurement liquid supply channel;
and a waste path through which the liquid whose specific resistance or conductivity is measured by the measuring unit is discharged. The liquid generation unit comprises:
a pure water supply source for supplying pure water;
a carbon dioxide source that supplies carbon dioxide;
a mixing unit for mixing pure water supplied from the pure water supply source and carbon dioxide supplied from the carbon dioxide supply source;
2. The cutting device according to claim 1, further comprising a carbon dioxide supply valve for adjusting the amount of carbon dioxide supplied from the carbon dioxide supply source to the mixing section. 3. The cutting apparatus according to claim 1, wherein the amount of the liquid supplied to the measuring liquid supply path is smaller than the amount of the liquid supplied to the machining liquid supply path. 4. The cutting apparatus according to claim 1, wherein said machining liquid supply unit further comprises a measurement liquid supply valve for adjusting the amount of said liquid supplied from said branch passage to said measurement unit. 5. The cutting apparatus according to any one of claims 1 to 4, further comprising a branch path for supplying the liquid supplied from the branch path to the machining liquid supply path and the cleaning liquid supply path.

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