JP7540908B2 - Processing Equipment - Google Patents

Description

The present invention relates to a processing device for processing workpieces such as semiconductor wafers.

A grinding device that uses a grinding wheel to grind a wafer held on a chuck table grinds the workpiece while supplying processing water (e.g., pure water) to the workpiece in a processing chamber that houses the chuck table and the grinding wheel. In addition, a water case that is located below the processing chamber and receives used processing water (waste liquid) has side plates, a bottom plate that connects the lower ends of the side plates, a top plate that connects the upper ends of the side plates, and a drain outlet formed at the part where the bottom plate and side plates are connected to discharge waste liquid containing processing debris outside the device.

During grinding, the grinding wheel may chip or the wafer may chip. To prevent large debris such as chipped grinding wheels or chipped wafers from clogging the drain pipe that connects to the waste liquid treatment device through the drain, a mesh basket is provided at the drain, as in the filtering device disclosed in Patent Document 1, for example.

Therefore, when the processing chamber is opened to replace the grinding wheel, the mesh basket can also be removed from the water case inside the processing chamber, allowing any broken grinding wheels or large debris such as chipped wafers that are caught in the mesh basket to be disposed of.

JP 2015-039759 A

However, because the mesh basket is located inside the processing chamber, workers cannot tell from the outside that large debris, such as a broken grinding wheel or chipped wafers, is caught in the mesh basket. In addition, the processing chamber must be opened to remove the mesh basket, so the supply of processing water, etc. must be stopped. This causes a change in temperature inside the processing chamber, and there is a problem in that after removing the large debris caught in the mesh basket, it takes time to return the temperature of the processing chamber to the original temperature suitable for processing and to process the wafers again.

Therefore, in processing equipment such as grinding equipment, there is a problem of being able to check whether large debris has accumulated in the mesh basket even while the workpiece is being processed, and being able to remove large debris caught in the mesh basket without changing the temperature of the processing chamber.

In order to solve the above problems, the present invention is a processing apparatus comprising a holding means for holding a workpiece, a processing means for processing the workpiece, a water supply section for supplying water to the workpiece, a water case for receiving waste liquid containing processing debris produced when the workpiece is processed by the processing means, and a drain outlet formed in the water case, the processing apparatus further comprising a drain box arranged on the side wall of the processing apparatus for receiving waste liquid containing processing debris flowing out of the water case, the drain box comprising a bottom plate, a side plate standing upright from the bottom plate, a top plate connected to the upper end of the side plate, a communication port formed in the side plate and communicating with the drain outlet of the water case, a drain outlet arranged at a lower position than the communication port for discharging the waste liquid, a mesh basket arranged at a lower position than the communication port for lowering the waste liquid toward the drain outlet , and a connecting rod connecting the top plate and the mesh basket.

In the processing device according to the present invention, it is preferable that the top plate or the side plate of the drainage box is made of a transparent material.

The processing device according to the present invention is provided with a drainage box arranged on the side wall of the processing device to receive waste liquid including processing debris flowing out of the water case. The drainage box is provided with a bottom plate, side plates standing from the bottom plate, a top plate connected to the upper end of the side plate, a communication port formed in the side plate and communicating with the drain port of the water case, a discharge port for discharging the waste liquid, a mesh basket arranged at a position lower than the communication port, and a connecting rod connecting the top plate and the mesh basket. By lifting the top plate of the drainage box located outside the processing chamber, the mesh basket connected to the top plate can also be removed. Therefore, it is possible to remove large debris caught in the mesh basket without opening the processing chamber when the processing device is idling and not processing, i.e., without changing the temperature inside the processing chamber.

In the processing device according to the present invention, the top plate or side plate of the drainage box is made of a transparent material, so that the worker can check from outside that large debris is caught in the mesh basket even while the processing device is performing the grinding process.

FIG. 2 is a perspective view showing an example of a processing device. FIG. 2 is a perspective view illustrating an example of a drainage box.

1 is an apparatus that uses processing means 7 to grind a workpiece 90 held on holding means 30, and the front (-Y direction side) on a base 10 in which the longitudinal direction of the processing apparatus 1 is the Y-axis direction is an area where the workpiece 90 is attached to and detached from the holding means 30, and the rear (+Y direction side) on the base 10 is an area where the workpiece 90 held on the holding means 30 is ground by the processing means 7. A box-shaped processing chamber 18 is formed in the area where the grinding is performed, and the processing means 7 and holding means 30 can enter and exit the processing chamber 18.
The processing device according to the present invention is not limited to a grinding device with a single-axis processing means 7 like the processing device 1, but may be a two-axis grinding device equipped with a rough grinding means and a finish grinding means, and capable of positioning the workpiece 90 below the rough grinding means or the finish grinding means using a rotating turntable. The processing device may also be a cutting device that cuts the workpiece into chips using a rotating cutting blade. The processing device may also be a polishing device that polishes the workpiece with a rotating polishing pad. Furthermore, the polishing device may be a dry polishing device. The dry polishing device drains water supplied to wash the workpiece or the inside of the processing chamber after polishing from a drain outlet of the water case.

The workpiece 90 is, for example, a circular semiconductor wafer made of a silicon base material or the like. Note that the workpiece 90 may be made of gallium arsenide, sapphire, gallium nitride, ceramics, resin, silicon carbide, or the like other than silicon, or may be a rectangular package substrate or the like. Furthermore, the workpiece 90 may have a device formed thereon, or may be a wafer cut from an ingot with no device formed thereon.

The holding means 30 shown in FIG. 1 for holding the workpiece 90 has, for example, a circular outer shape and includes an adsorption part 300 made of a porous material or the like for adsorbing the workpiece 90, and a frame 301 for supporting the adsorption part 300. The adsorption part 300 is connected to a suction source (not shown) and adsorbs and holds the workpiece 90 on a holding surface 302, which is the exposed surface of the adsorption part 300. The holding surface 302 is, for example, an extremely gentle conical slope with the center of rotation of the holding means 30 as its apex.

As shown in FIG. 1, the holding means 30 is surrounded by a cover 39, and can be rotated about a rotation axis in the Z-axis direction by a table rotation means (not shown) arranged below the cover 39. The holding means 30 can also be moved back and forth in the Y-axis direction by a Y-axis moving means (not shown) arranged below the cover 39 shown in FIG. 1 and a bellows cover 390 connected to the cover 39.

In the grinding area on the base 10 shown in FIG. 1, a column 11 is erected, and a grinding feed means 5 is arranged on the front of the column 11 to grind and feed the processing means 7 in the Z-axis direction (vertical direction) away from or toward the holding means 30. The grinding feed means 5 includes a ball screw 50 having a vertical axis, a pair of guide rails 51 arranged parallel to the ball screw 50, a motor 52 connected to the upper end of the ball screw 50 to rotate the ball screw 50, and a lift plate 53 whose internal nut is screwed into the ball screw 50 and whose side is in sliding contact with the guide rail 51. When the motor 52 rotates the ball screw 50, the lift plate 53 is guided by the guide rail 51 and moves back and forth in the Z-axis direction, and the processing means 7 fixed to the lift plate 53 is ground and fed in the Z-axis direction.

The processing means 7 that grinds the workpiece 90 held by the holding means 30 includes a spindle 70 whose axial direction is the Z-axis direction, a housing 71 that rotatably supports the spindle 70, a motor 72 that rotates and drives the spindle 70, a disk-shaped mount 73 connected to the lower end of the spindle 70, a grinding wheel 74 that is detachably attached to the lower surface of the mount 73, and a holder 75 that supports the housing 71 and has its side fixed to the lift plate 53 of the grinding feed means 5.

The grinding wheel 74 comprises a wheel base 741 having a circular shape in a plan view, and a number of grinding stones 740 having a roughly rectangular shape arranged in a ring shape on the underside of the wheel base 741. The grinding stones 740 are formed by bonding diamond abrasive grains or the like with an appropriate binder (adhesive), and the underside thereof is mainly the grinding surface.

A flow passage (not shown) that communicates with a processing water supply source 60 storing pure water or the like and serves as a passage for processing water is provided inside the spindle 70 in the axial direction of the spindle 70, and the flow passage (not shown) further passes through a mount 73 and opens at the bottom surface of the wheel base 741 so that processing water can be sprayed toward the grinding wheel 740. The flow passage and the processing water supply source 60 constitute a water supply unit 6 that supplies processing water to the workpiece 90.
During grinding, the grinding wheel 74 is positioned so that a portion of it horizontally protrudes from the holding means 30, so a processing water injection nozzle arranged inside the protruding portion of the grinding wheel 74 may serve as the water supply section.

On both sides of the movement path of the holding means 30, waste liquid inlets 43 of the water case 4 are formed to receive processing water (waste liquid) containing processing debris generated when the workpiece 90 is processed by the processing means 7. The water case 4 disposed inside the base 10 is formed in a rectangular tub shape in a plan view and has a rectangular opening (not shown) in the center. A Y-axis movement means (not shown), such as a ball screw mechanism, that moves the holding means 30 back and forth in the Y-axis direction is disposed within the opening, which is separated by a wall panel.

In one area of the water case 4, i.e., for example, at one of the four corners, where the side wall 40 and the bottom plate 41 are connected, a drainage port 42 is formed through the side wall 40 of the water case. In addition, for example, one or more flow nozzles (not shown) are arranged in the water case 4 to spray water and cause waste liquid including machining chips received in the water case 4, such as fine grinding chips, chipped pieces of the grinding wheel 740 (large machining chips), or chipped pieces of the workpiece 90 (large machining chips), to flow toward the drainage port 42 within the water case 4.

One end of a drain pipe 424 made of a metal pipe, a drain hose, or the like is connected to the drain outlet 42. For example, the drain pipe 424 extends inside the base 10 in the Y-axis direction, and the other end opens into the rear wall 102 of the base 10, and is connected to a drain box 2 arranged outside the base 10.

The processing device 1 is provided with a drainage box 2 that is disposed on a side wall of the processing device 1 (in this embodiment, the rear wall 102 of the base 10) and receives waste liquid containing processing debris that flows out of the water case 4. Note that the location of the drainage box 2 is not limited to the rear wall 102, and it may be disposed on a side wall other than the rear wall 102 so as to reduce the footprint of the processing device 1.

The drain box 2 comprises a bottom plate 20, side plates standing upright from the bottom plate 20, a top plate 22 connected to the upper ends of the side plates, a communication port 24 formed in the side plate and connected to the drain port 42 of the water case 4 via a drain pipe 424, a drain port 25 for discharging waste liquid, a mesh basket 27 shown in FIG. 2 that is positioned lower than the communication port 24, and a connecting rod 28 shown in FIG. 2 that connects the top plate 22 and the mesh basket 27.

The bottom plate 20 is, for example, generally rectangular in plan view. In this embodiment, the two side plates facing each other in the X-axis direction in FIG. 2 are side plates 211 and 212, and the two side plates facing each other in the Y-axis direction are side plates 214 and 215. A communication port 24 is formed through the side plate 214.

In this embodiment, the drain outlet 25 is formed at the connection portion between the side plate 215 and the bottom plate 20 so as to face, for example, in the +Y direction. The drain outlet 25 may face the -Z direction. The drain outlet 25 is connected, for example, to a waste liquid treatment device (not shown). The waste liquid treatment device, for example, submerges an anode plate and a cathode plate at a predetermined interval in a liquid tank that stores processing waste liquid, supplies DC power to the cathode plate and the anode plate, attaches negatively charged fine processing debris (fine processing debris that was not removed from the waste liquid by the mesh basket 27) to the positively charged anode plate, and circulates the purified water from which the processing debris has been removed back to the processing device 1.

In this embodiment, the top plate 22 is formed of a transparent material such as glass or plastic (e.g., polycarbonate, etc.). The entire top plate 22 may be formed of a transparent material, or only the central region of the top plate 22 may be formed of a transparent material large enough for an operator to look into the inside of the drainage box 2.
A handle 227 that can be gripped by an operator is provided on the upper surface of the top plate 22.

The mesh basket 27 made of stainless steel mesh material or the like is formed, for example, in a box shape slightly smaller than the bottom plate 20 of the drainage box 2, and is removably arranged on the bottom plate 20 of the drainage box 2 in a state where it is fixed on a liquid passage plate 270 having an external shape similar to that of the mesh basket 27 and having a plurality of punched holes. The mesh size of the mesh basket 27 is set to a size that does not allow large processing debris such as the grinding wheel 740 chipped during grinding and the chipped workpiece 90 to pass through. The liquid passage plate 270 may be omitted.
When the mesh basket 27 is housed inside the drainage box 2, it is positioned at a lower height than the communication port 24, and waste liquid flows down from the communication port 24.

For example, one side wall 276 of the liquid passage plate 270 to which the mesh basket 27 is fixed (in the example shown in FIG. 2, the side wall 276 on the +Y direction side) is set higher than the other side walls, and the lower ends of, for example, two connecting rods 28 are attached to the side wall 276, and the upper ends of the connecting rods 28 are connected to the top plate 22. Then, the liquid passage plate 270 and the mesh basket 27 are housed inside the drainage box 2, and the top plate 22 covers the upper opening of the drainage box 2.

The operation of the processing apparatus 1 shown in FIG. 1 when grinding the workpiece 90 held by the holding means 30 will be described below.
In the attachment/detachment area, the workpiece 90 is placed on the holding surface 302 of the holding means 30 with their centers substantially aligned. Then, a suction force generated by a suction source (not shown) is transmitted to the holding surface 302, and the holding means 30 suction-holds the workpiece 90 on the holding surface 302.

Next, the holding means 30, which has suction-held the workpiece 90, moves in the +Y direction from the attachment/detachment area to below the processing means 7 in the processing area, and the center of rotation of the grinding wheel 740 of the processing means 7 is shifted horizontally by a predetermined distance relative to the center of rotation of the workpiece 90, and the holding means 30 is positioned so that the rotational trajectory of the grinding wheel 740 passes through the center of rotation of the workpiece 90.

Then, the processing means 7 is sent in the -Z direction by the grinding feed means 5, and the rotating grinding wheel 740 comes into contact with the upper surface of the workpiece 90, thereby performing grinding. During grinding, as the holding means 30 rotates at a predetermined rotation speed, the workpiece 90 held on the holding surface 302 also rotates, so that the grinding wheel 740 grinds the entire upper surface of the workpiece 90.

During grinding, processing water is supplied from the water supply unit 6 through the spindle 70 to the contact area between the grinding wheel 740 and the top surface of the workpiece 90, cooling and cleaning the contact area. Used processing water (waste liquid) containing powdered processing debris generated by grinding, large pieces of the chipped grinding wheel 740, or large pieces of the chipped workpiece 90 flows over the holding surface 302 and the cover 39, and flows down into the water case 4 from the waste liquid inlets 43 on both sides of the cover 39.

The water flow generated by the flow nozzle (not shown) carries waste liquid containing powdered chips generated by grinding, large pieces of the chipped grinding wheel 740, or large pieces of the chipped workpiece 90 toward the drain port 42 in the water case 4, passes through the drain port 42 and the drain pipe 424, and then flows into the drain box 2 through the communication port 24.

The waste liquid flows down toward the mesh basket 27 located below the communication port 24. For example, a certain gap is provided between the mesh basket 27 and the liquid passage plate 270, which are supported by the top plate 22 via the connecting rod 28 and housed in the drainage box 2, and the bottom plate 20 of the drainage box 2. The waste liquid from which large processing debris, such as large pieces of the grinding wheel 740 or large pieces of the chipped workpiece 90, has been removed by the mesh basket 27 passes through the punched holes in the liquid passage plate 270, reaches the gap, and flows from the discharge port 25 to a waste liquid treatment device (not shown).

In this embodiment, since the top plate 22 is made of a transparent material, for example, when the processing device 1 is processing the workpiece 90, if an operator who checks the inside of the drainage box 2 through the top plate 22 determines that the mesh basket 27 is full of large pieces of the grinding wheel 740 or large pieces of the chipped workpiece 90, or when the grinding processing of the multiple workpieces 90 scheduled in advance is completed, the grinding operation of the processing device 1 shown in FIG. 1 can be stopped once and the processing device 1 can be put into an idling state (a state in which large processing debris does not flow into the drainage box 2), and the operator can then lift the top plate 22 and remove the mesh basket 27 from the drainage box 2, and dispose of the large pieces of the grinding wheel 740 or large pieces of the chipped workpiece 90 in the mesh basket 27.

As described above, the processing device 1 according to the present invention is provided with a drainage box 2 that is disposed on a side wall of the processing device 1 (e.g., the rear wall 102 of the base 10) and receives waste liquid including processing debris that flows out of the water case 4. The drainage box 2 includes a bottom plate 20, side plates 211, 212, 214, and 215 that stand upright from the bottom plate 20, a top plate 22 that is connected to the upper ends of the side plates 211 to 215, a communication port 24 formed in the side plate 215 and communicating with the drain port 42 of the water case 4, and a drain hole 25 for discharging the waste liquid. The drainage box 2 is provided with a drain outlet 25, a mesh basket 27 located at a lower position than the communication port 24, and a connecting rod 28 connecting the top plate 22 and the mesh basket 27. By lifting the top plate 22 of the drainage box 2, the mesh basket 27 connected to the top plate 22 can also be removed. This makes it possible to remove large processing debris caught in the mesh basket 27 without opening the processing chamber 18, i.e., without changing the temperature inside the processing chamber 18, during idling when the processing device 1 is not processing. In addition, it is possible to remove and discard large pieces of the grinding wheel 740 or large pieces of the chipped workpiece 90 using the mesh basket 27 without the worker having to take action such as snatching the bottom of the water case 4.

Furthermore, in the processing device 1 according to the present invention, since the top plate 22 is formed from a transparent material, it is possible for an operator, etc. to confirm that large debris is caught in the mesh basket 27 even while the processing device 1 is performing grinding processing.
The side plate 211, the side plate 212, or the side plate 215 of the drainage box 2 may be formed of a transparent material. Furthermore, the top plate 22 and the side plate 211, the side plate 212, or the side plate 215 may be formed of a transparent material.

The processing device 1 according to the present invention is not limited to the above embodiment, and can be modified as appropriate within the scope in which the effects of the present invention can be achieved.

90: Workpiece
1: Processing device 10: Base 102: Rear wall of base 18: Processing chamber 30: Holding means 302: Holding surface 39: Cover 390: Bellows cover 11: Column 5: Grinding feed means 7: Processing means 74: Grinding wheel 740: Grinding wheel 6: Water supply section 60: Processing water supply source 4: Water case 43: Waste liquid inlet 40: Side wall of water case 41: Bottom plate of water case 42: Drain port 424: Drain pipe 2: Drain box 20: Bottom plate of drain box 211, 212, 214, 215: Side plate of drain box 22: Top plate of drain box 227: Handle 25: Drain outlet of drain box 24: Communication port of drain box 27: Mesh basket 270: Liquid passage plate 28: Connecting rod

Claims (2)

A processing device comprising: a holding means for holding a workpiece; a processing means for processing the workpiece; a water supplying section for supplying water to the workpiece; a water case for receiving waste liquid including processing waste generated when the workpiece is processed by the processing means; and a drainage outlet formed in the water case,
a drainage box disposed on a side wall of the processing device for receiving waste liquid containing the processing waste flowing out from the water case;
The drainage box is a processing device comprising a bottom plate, side plates standing up from the bottom plate, a top plate connected to the upper ends of the side plates, a communication port formed in the side plates and communicating with the drain port of the water case, a discharge port located lower than the communication port for discharging waste liquid, a mesh basket located lower than the communication port for lowering the waste liquid toward the discharge port , and a connecting rod connecting the top plate and the mesh basket. The processing device according to claim 1, wherein the top plate of the drainage box is made of a transparent material.

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