JP5779083B2 - Processing waste liquid treatment equipment - Google Patents

Description

  The present invention relates to a processing waste liquid processing apparatus attached to a processing apparatus such as a cutting apparatus for cutting a workpiece such as a semiconductor wafer or a grinding apparatus for grinding a workpiece, and processing a waste liquid of a processing liquid supplied during processing. .

  In the semiconductor device manufacturing process, a plurality of regions are partitioned by dividing lines called streets arranged in a lattice pattern on the surface of a substantially wafer-shaped semiconductor wafer, and devices such as ICs, LSIs, etc. are partitioned in the partitioned regions. Form. By cutting the semiconductor wafer having the device formed on the surface in this way along the street, the region where the device is formed is divided to manufacture individual semiconductor devices.

  The above-described cutting along the street of the semiconductor wafer is usually performed by a cutting device called a dicer. This cutting apparatus includes a chuck table for holding a workpiece such as a semiconductor wafer, a cutting means having a cutting blade for cutting the workpiece held on the chuck table, and supplying cutting water to the cutting blade. A cutting water supply means for cooling the cutting blade by supplying the cutting water to the cutting blade that rotates, and supplying the cutting water to the cutting portion of the workpiece by the cutting blade. Carry out cutting work.

  The wafer divided in this way is ground to a predetermined thickness by a grinding device before being cut along the street. The grinding apparatus includes a chuck table that holds a workpiece, and a grinding unit that grinds the workpiece held on the chuck table. The grinding means includes a rotary spindle, a wheel mount provided at the lower end of the rotary spindle, and a grinding wheel that is detachably attached to the lower surface of the wheel mount. And a plurality of grinding wheels mounted on the outer peripheral grinding wheel mounting portion on the lower surface of the wheel base, and the grinding wheel is held on the chuck table while rotating the grinding wheel and supplying the grinding water The workpiece is ground by pressing against the workpiece.

  As described above, silicon fine particles generated by cutting or grinding silicon are mixed in the machining fluid supplied during cutting by the cutting device or grinding by the grinding device. Since the processing waste liquid mixed with the silicon fine particles contaminates the environment, the processing waste liquid has to be treated and drained, resulting in a problem of waste liquid processing cost.

  In order to solve the above problem, a processing waste liquid treatment apparatus has been proposed in which processing waste liquid is filtered through a filter to generate fresh water, and is circulated and used as cutting water or grinding water (for example, see Patent Document 1).

JP 2009-95941 A

Thus, the above-described processing waste liquid treatment apparatus has to be replaced with a new filter, resulting in a new problem of poor productivity. In particular, in a processing waste liquid treatment apparatus attached to a grinding apparatus for grinding a silicon wafer having a thickness of about 600 μm to a thickness of about 100 μm, a large amount of grinding debris is generated, and therefore, the work of exchanging the filter is frequent.
In addition, since silicon fine particles as grinding waste are captured by the filter, it is possible to recover the silicon ingot by collecting the silicon fine particles from the filter, but it is difficult to efficiently recover the silicon fine particles that have penetrated the filter. It is.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is that silicon fine particles can be separated from processing waste liquid containing silicon fine particles as cutting scraps or grinding scraps to generate clean water, and silicon An object of the present invention is to provide a processing waste liquid treatment apparatus capable of efficiently collecting fine particles.

In order to solve the main technical problem, according to the present invention, in a processing waste liquid treatment apparatus for separating processing waste liquid mixed with silicon fine particles into silicon fine particles and fresh water,
A waste liquid treatment tank for treating the processing waste liquid, and a silicon separation mechanism for separating silicon fine particles from the processing waste liquid contained in the waste liquid treatment tank,
The waste liquid treatment tank is provided with a processing waste liquid inlet on one end wall in the longitudinal direction and a fresh water outlet on the other end wall.
The silicon separation mechanism is disposed in the waste liquid treatment tank in parallel with each other along the longitudinal direction and is provided with a plurality of cathode plates that are negatively charged and facing the plurality of cathode plates. An anode plate unit including a plurality of positively charged anode plates, and the anode plate unit is configured to be removable.
A processing waste liquid treatment apparatus is provided.

  The anode plate unit is divided into a plurality along the longitudinal direction.

  The processing waste liquid treatment apparatus according to the present invention includes a waste liquid treatment tank for treating the machining waste liquid, and a silicon separation mechanism for separating silicon fine particles from the processing waste liquid accommodated in the waste liquid treatment tank. A processing waste liquid inlet is provided on one end wall, and a fresh water outlet is provided on the other end wall. The silicon separation mechanism is spaced parallel to each other along the longitudinal direction in the waste treatment tank. A plurality of negatively charged cathode plates, and an anode plate unit provided with a plurality of positively charged anode plates arranged opposite to the negative electrode plates, so that waste liquid treatment is possible. The processing waste liquid flowing into the waste liquid treatment tank from the processing waste liquid inlet provided on one side wall of the tank is separated into silicon fine particles adsorbed by the plurality of anode plates of the anode plate unit and fresh water. In this way, the separated silicon fine particles are adsorbed and deposited on the plurality of anode plates of the anode plate unit, and the fresh water flows out through the fresh water outlet provided on the other side wall of the waste liquid treatment tank and is conveyed to the fresh water tank. The Therefore, silicon fine particles can be separated efficiently and fresh water can be easily generated from the processing waste liquid by flowing a predetermined amount of the processing waste liquid from the processing waste liquid inlet provided on one side wall of the waste liquid treatment tank. .

The perspective view of the processing waste liquid processing apparatus comprised according to this invention. The perspective view which decomposes | disassembles and shows the waste liquid processing tank and silicon peeling means which comprise the process waste liquid processing apparatus shown in FIG. AA line sectional view in FIG. The perspective view of the silicon | silicone collection | recovery apparatus for collect | recovering the silicon particulates isolate | separated by the processing waste liquid processing apparatus shown in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a processing waste liquid treatment apparatus configured according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a perspective view of a processing waste liquid treatment apparatus constructed according to the present invention.
The processing waste liquid treatment apparatus 1 in the illustrated embodiment includes a waste liquid treatment tank 2 for treating the machining waste liquid, and a silicon separation mechanism 3 that separates silicon fine particles from the processing waste liquid stored in the waste liquid treatment tank 2. Yes. As shown in FIG. 2, the waste liquid treatment tank 2 includes a bottom wall 21 having a large length with respect to the width direction, side walls 22 and 23 erected from both side edges of the bottom wall 21, and the bottom wall 21. Formed by end walls 24 and 25 erected from both side edges in the longitudinal direction, the upper side is released. A processing waste liquid inlet 241 is provided at the lower part of one end wall 24 constituting the waste liquid treatment tank 2, and a fresh water outlet 251 is provided at the upper part of the other end wall 25. The waste liquid treatment tank 2 configured as described above is formed of an insulating member such as a synthetic resin. The bottom wall 21 and the end walls 24 and 25 are formed so that the central portions protrude outwardly, and liquid reservoirs are formed at both ends of the waste liquid treatment tank 2, respectively.

  As shown in FIGS. 2 and 3, the silicon separation mechanism 3 includes a cathode unit 31 disposed in the waste liquid treatment tank 2 and an anode plate unit 32 that is detachably attached to the waste liquid treatment tank 2. . The cathode unit 31 is formed of an insulating member such as a synthetic resin, and includes a support plate 311 and a plurality of cathode plates 312 made of a conductive member such as copper or stainless steel, which is erected on the upper surface of the support plate 311. It is made up of. The support plate 311 has a width corresponding to the dimension corresponding to the inner surfaces of the side walls 22 and 23 constituting the waste liquid treatment tank 2, and the length substantially corresponds to the length of the bottom wall 21 constituting the waste liquid treatment tank 2. It is formed to the dimension to be. The plurality of cathode plates 312 are disposed in the waste liquid treatment tank 2 in parallel with each other along the side walls 22 and 23 that are in the longitudinal direction. Thus, the plurality of cathode plates 312 arranged in the waste liquid treatment tank 2 are connected to electrode terminals 313 mounted on the side walls 22 constituting the waste liquid treatment tank 2.

  The anode plate unit 32 includes a support plate 321 formed of an insulating member such as a synthetic resin, and a plurality of anode plates 322 made of a conductive member such as copper or stainless steel disposed on the lower surface of the support plate 321. ing. In the illustrated embodiment, the support plate 321 has a width corresponding to the dimension corresponding to the outer surface of the side walls 22 and 23 constituting the waste liquid treatment tank 2, and the length is the length of the plurality of cathode plates 312. It is formed in a dimension corresponding to approximately one third, and a handle 323 is attached to the upper surface. The plurality of anode plates 322 are disposed in parallel with each other along the length direction. The intervals between the plurality of anode plates 322 are set to be the same as the intervals between the plurality of cathode plates 312, and are shifted by a half of the intervals. A plurality of anode plates 322 constituting the anode plate unit 32 are connected to electrode terminals 324 mounted on the support plate 321.

  As shown in FIG. 3, the anode plate unit 32 configured as described above has a plurality of anode plates 322 inserted between a plurality of cathode plates 312 and mounted so as to face the plurality of cathode plates 312. In the illustrated embodiment, as shown in FIG. 1, three anode plate units 32 are detachably attached to the waste liquid treatment tank 2. In the processing waste liquid treatment apparatus 1 configured as described above, the electrode terminal 324 of each anode plate unit 32 is connected to the plus (+) of the DC power supply 4, and the electrode terminal 313 of the cathode unit 31 is minus (−) of the DC power supply 4. ).

The processing waste liquid treatment apparatus 1 in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
The processing waste liquid sent from the processing waste liquid sending means provided in a processing apparatus such as a grinding apparatus (not shown) and stored in a waste liquid tank (not shown) is a processing waste liquid inlet 241 provided on one end wall 24 of the waste liquid treatment tank 2. To the waste liquid treatment tank 2. In this manner, silicon fine particles are mixed in the processing waste liquid sent to the waste liquid treatment tank 2, and the silicon fine particles are charged to minus (−). In order to separate the silicon fine particles mixed in the processing waste liquid stored in the waste liquid treatment tank 2 in this way, the positive electrode of the DC power source 4 is added to the plurality of anode plates 322 of the anode plate unit 32 constituting the silicon separation mechanism 3. (+) Is applied, and minus (−) of the DC power supply 4 is applied to the plurality of cathode plates 312 of the cathode unit 31. As a result, the silicon fine particles mixed in the processing waste liquid and negatively charged (−) are repelled from the plurality of cathode plates 312 of the negatively charged negative electrode unit 31 and positively charged (+). Adsorbed to the plurality of anode plates 322 of the plate unit 32.

  As described above, the processing waste liquid that has flowed into the waste liquid treatment tank 2 from the processing waste liquid inlet 241 provided on one end wall 24 of the waste liquid treatment tank 2 is adsorbed by the plurality of anode plates 322 of the anode plate unit 32. Separated into fine silicon particles and fresh water. In this way, the separated silicon fine particles are adsorbed and deposited on the plurality of anode plates 322 of the anode plate unit 32, and the fresh water flows out through the fresh water outlet 251 provided on the other end wall 25 of the waste liquid treatment tank 2. Then, it is conveyed to a fresh water tank (not shown). Therefore, silicon fine particles can be separated efficiently by flowing a predetermined amount of processing waste liquid from a processing waste liquid inlet 241 provided on one end wall 24 of the waste liquid treatment tank 2, and clean water can be easily generated from the processing waste liquid. can do.

  When the processing process of the processing waste liquid described above is performed for a predetermined time and silicon fine particles are deposited on the plurality of anode plates 322 constituting the anode plate unit 32, the silicon recovery for peeling and collecting the silicon fine particles deposited on the anode plate 322 is performed. A process is performed. This silicon recovery process is performed using, for example, a silicon recovery apparatus 5 shown in FIG. The silicon recovery device 5 includes a silicon recovery box 51 and silicon peeling means 52 disposed in the silicon recovery box 51. The silicon recovery box 51 is formed by a rectangular bottom plate 511, side plates 512 and 513 erected from both lateral edges of the bottom plate 511, and end plates 514 and 515 erected from both longitudinal edges of the bottom plate 511. The upper side is released. The width of the bottom plate 511 is formed to be one sheet of the cathode plate 312 larger than the width of the bottom wall 21 constituting the waste liquid treatment tank 2, and the length of the bottom plate 511 is about three times the length of the anode plate unit 32. Is set to

  The silicon peeling means 52 disposed in the silicon recovery box 51 includes a plurality of brush support plates 521 erected at the center in the longitudinal direction of the bottom plate 511 constituting the silicon recovery box 51, and the plurality of brush supports. The peeling brush 522 is attached to the plate 521. In the illustrated embodiment, the plurality of brush support plates 521 are formed to have a length equal to or shorter than the length of the anode plate unit 32, and have a predetermined interval parallel to the side plates 512 and 513 constituting the silicon recovery box 51. Is arranged. The intervals between the plurality of brush support plates 521 are set to be the same as the intervals between the plurality of anode plates 322 constituting the anode plate unit 32 of the silicon separation mechanism 3 and are shifted by a half of the intervals. Is done. In this way, the plurality of brush support plates 521 disposed on the bottom plate 511 constituting the silicon recovery box 51 are each mounted with the peeling brush 522 on the facing surface. By disposing the silicon peeling means 52 as described above, the space for housing the anode plate unit 32 between the end plates 514 and 515 and the silicon peeling means 52 is disposed on both sides in the longitudinal direction of the silicon recovery box 51. 51a and 51b are formed.

  In order to perform the silicon recovery step of peeling and recovering silicon fine particles deposited on the plurality of anode plates 322 constituting the anode plate unit 32 using the silicon recovery device 5 described above, the processing step of the processing waste liquid described above is performed. By carrying out, the anode plate unit 32 including the anode plate 322 on which silicon fine particles are deposited is removed from the waste liquid treatment tank 2 of the processing waste liquid treatment apparatus 1 with the handle 323. And it inserts in one space 51a from the upper direction of the silicon | silicone collection | recovery box 51 which comprises the silicon | silicone collection | recovery apparatus 5. FIG. Next, the anode plate unit 32 is moved toward the silicon peeling means 52 and the other space 51b. As a result, when the plurality of anode plates 322 of the anode plate unit 32 pass between the plurality of brush support plates 521 constituting the silicon peeling means 52, the silicon fine particles accumulated on the plurality of anode plates 322 are the plurality of brush support plates. It is peeled off by the peeling brush 522 attached to 521 and recovered in the silicon recovery box 51. When carrying out this silicon recovery step, the anode plate unit 32 is divided into three parts in the illustrated embodiment, so that the handling is easy.

1: Processing waste liquid treatment device 2: Waste liquid treatment tank 241: Processing waste liquid inlet 251: Fresh water outlet 3: Silicon separation mechanism 31: Cathode unit 311: Support plate 312: Multiple cathode plates 313: Electrode terminal 32: Anode plate unit 321: Support plate 322: Plural anode plates 323: Handle 324: Electrode terminal 4: DC power supply 5: Silicon recovery device 51: Silicon recovery box 52: Silicon peeling means

Claims (2)

In processing waste liquid treatment equipment that separates processing waste liquid mixed with silicon fine particles into silicon fine particles and fresh water,
A waste liquid treatment tank for treating the processing waste liquid, and a silicon separation mechanism for separating silicon fine particles from the processing waste liquid contained in the waste liquid treatment tank,
The waste liquid treatment tank is provided with a processing waste liquid inlet on one end wall in the longitudinal direction and a fresh water outlet on the other end wall.
The silicon separation mechanism includes a plurality of cathode plates disposed in the waste liquid treatment tank at intervals in parallel with each other along a longitudinal direction, and a plurality of anodes disposed so as to face the plurality of cathode plates. An anode plate unit provided with a plate, the anode plate unit is configured to be removable.
A processing waste liquid treatment apparatus characterized by that.   The processing waste liquid treatment apparatus according to claim 1, wherein the anode plate unit is divided into a plurality along the longitudinal direction.

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