JP4909575B2 - Cleaning method and cleaning equipment - Google Patents

Description

  The present invention relates to a cleaning method and a cleaning apparatus, and more particularly, to a cleaning method and a cleaning apparatus for suitably removing cutting chips present in a cutting groove formed on the surface of a workpiece.

  For example, in a semiconductor device manufacturing process, a substantially disc-shaped semiconductor wafer is cut along cutting lines (streets) arranged in a lattice pattern on the surface thereof to form a circuit such as an IC or LSI. Divide into multiple semiconductor chips. The semiconductor chip thus divided is packaged and widely used in electronic devices such as mobile phones and computer devices.

  Such cutting is generally performed using a cutting device such as a dicing device. This cutting apparatus includes, for example, a cutting blade having a cutting wheel portion made of diamond abrasive grains and a chuck table for holding a workpiece such as a semiconductor wafer, and the cutting blade rotated at high speed is processed. While cutting, the workpiece is relatively cut and fed along the cutting line to cut the workpiece to form a cutting groove.

  In such a cutting apparatus, when the workpiece is cut by rotating the cutting blade at a high speed, frictional heat generated between the cutting blade and the workpiece causes wear and damage of the cutting blade, cutting grooves of the workpiece. Cause chipping. For this reason, a method of cooling by supplying a cutting fluid (such as cutting water) to a cutting blade or a processing point is employed.

  However, the cutting fluid supplied to the machining point drains together with the cutting waste generated by the cutting and flows onto the surface of the workpiece, so that the cutting waste adheres to the surface of the workpiece. . In particular, when cutting waste enters a cutting groove formed by cutting, the workpiece may be cleaned in a cleaning process (for example, a spinner cleaning process) that is a subsequent process of the cutting process. There was a problem that it was almost impossible to clean and remove cutting waste. If cutting chips adhere to the inside of the cutting chips or the like in this way, at the time of picking up the chip, which is a divided workpiece, in the die bonding process, which is a subsequent process, the cutting chips fall from the chip, and the inside of the production line. Foreign matter may be mixed into the product, causing product defects.

  In order to cope with such a problem, Patent Document 1 discloses that in a cleaning device provided in a cutting device, an ultrasonic vibrator is installed in a nozzle that ejects cleaning water, and the cleaning water that is ultrasonically vibrated from the nozzle is processed. A cleaning method is described in which the cutting waste adhering to the surface of the workpiece is removed by spraying the workpiece.

  However, even if the ultrasonically oscillated cleaning water is sprayed from the nozzle as described in Patent Document 1, the cleaning effect by the ultrasonic vibration of the cleaning water is not sufficient, and it is not very effective for fine cutting waste. I found out that there was no.

  Therefore, Patent Document 2 proposes a method of cleaning the surface of a machined workpiece by ultrasonically vibrating the entire cleaning water film placed on the surface of the workpiece. According to this cleaning method, since the cleaning water on the surface of the workpiece always vibrates ultrasonically, the cleaning effect by ultrasonic vibration can be enhanced.

JP-A-11-2143333 JP 2002-280343 A

  However, even in the cleaning method described in Patent Document 2, the vibration applied to the cleaning water is attenuated by the wall surface of the cutting groove and does not reach the bottom of the cutting groove. There was a problem that it could not be removed properly. As described above, in the conventional cleaning method, the bottom portion in the cutting groove, which is the part where the cutting scraps are most present, cannot be properly cleaned in the cut workpiece.

  Therefore, the present invention has been made in view of such a problem, and the object thereof is a novel that can suitably clean and remove cutting waste existing in a cutting groove formed in a workpiece. Another object of the present invention is to provide an improved cleaning method and apparatus.

In order to solve the above-described problems, according to one aspect of the present invention, a holding unit that holds a workpiece in a state in which the surface is facing upward, and a cutting that cuts the workpiece that is held by the holding unit. In a cutting apparatus comprising a blade and a cutting fluid supply means for supplying a cutting fluid to the surface of the workpiece, the workpiece having a cutting groove formed on the surface by cutting with the cutting blade is used as the cutting groove. A cleaning method for cleaning in order to remove cutting waste existing in the holding means , wherein the holding means is formed with a recessed portion capable of accommodating the workpiece on the upper surface thereof, and is supplied from the cutting fluid supply means. The cutting fluid can be stored as a cleaning fluid in the recess, and the lower side of the recess of the holding means is the same as the depth direction of the cutting groove of the workpiece held by the holding means. Said holding in direction The stage has ultrasonic transducers provided to ultrasonic vibration, the while supplying to the workpiece the cutting fluid as the cleaning liquid by the cutting liquid supply means, by the holding means, the processed in the recess Holding the object in a state where it is submerged in the cleaning liquid with the surface facing upward, the ultrasonic vibrator generates a cleaning force that peels and lifts up the cutting waste clogged at the bottom of the cutting groove. The workpiece held in the cleaning liquid is ultrasonically vibrated in the same direction as the depth direction of the cutting groove to clean and remove the cutting waste in the cutting groove. A cleaning method is provided.

  With this configuration, when the holding means is ultrasonically vibrated by the ultrasonic vibrator provided in the holding means, the workpiece itself held by the holding means is ultrasonically vibrated in the vertical direction from the lower surface side. As a result, an impact force or cavitation is generated from the bottom of the cutting groove formed in the workpiece, and a cleaning force is generated so that the cutting waste existing at the bottom of the cutting groove is lifted off from below. it can. Therefore, even cutting chips existing in the cutting groove of the workpiece can be suitably cleaned and removed from the cutting groove.

In order to solve the above problems, according to another aspect of the present invention , holding means for holding a workpiece in a state in which the surface faces upward, and cutting the workpiece held by the holding means. Workpiece provided with a cutting blade having a cutting blade to be machined and a cutting fluid supply means for supplying a cutting fluid to the surface of the workpiece, and having a cutting groove formed on the surface by cutting with the cutting blade Is a cleaning device for cleaning the cutting swarf existing in the cutting groove, and the holding means is formed with a recessed portion capable of accommodating the workpiece on the upper surface thereof. The cutting fluid supplied from the liquid supply means can be stored in the recess as a cleaning liquid, and the cutting groove of the workpiece held by the holding means is formed on the lower side of the recess of the holding means. In the same direction as the depth direction The serial holding means and the ultrasonic transducer is provided to the ultrasonic vibration, the while supplying to the workpiece the cutting fluid as the cleaning liquid by the cutting liquid supply means, by the holding means, it said in the recess It was held in a state of being immersed in the workpiece in said washing liquid, wherein the ultrasonic vibrator, to generate a cleaning force to float by peeling off cutting debris jammed in the bottom of the cutting groove, the cleaning solution The workpiece held in a submerged state is ultrasonically vibrated in the same direction as the depth direction of the cutting groove to clean and remove cutting waste in the cutting groove . A cleaning device is provided.

  With this configuration, it is possible to provide a cleaning apparatus that suitably executes the cleaning method.

  The holding means may hold the workpiece in a state where it is submerged in the cleaning liquid. As a result, the workpiece submerged in the cleaning liquid is ultrasonically vibrated, so that the cutting waste in the cutting groove of the workpiece can be easily detached from the cutting groove and suspended in the cleaning liquid. The effect can be enhanced.

Further, when the workpiece is not cut by the cutting blade, the cutting waste in the cutting groove may be washed and removed .

  With this configuration, the cleaning method can be suitably executed by using the holding unit and the cutting fluid supply unit of the cutting apparatus. Further, the workpiece is cleaned by ultrasonic vibration when the workpiece is not cut by the cutting blade. Thereby, the workpiece can be ultrasonically cleaned on the holding means of the cutting apparatus. The reason why the ultrasonic vibration is not applied during the cutting process is that, depending on the type of the work piece (for example, a work piece made of a crystalline material such as silicon), the work piece is ultrasonically vibrated during the cutting process. This is because chipping or the like occurs in the workpiece to be cut and the product quality deteriorates.

  In addition, when the workpiece is not being cut by the cutting blade, the cutting blade may be moved between cutting lines of the workpiece. Thereby, while the cutting blade moves between the cutting lines, the ultrasonic vibrator can be operated to efficiently ultrasonically clean the cutting groove of the workpiece.

  The time when the workpiece is not cut by the cutting blade may be after all the cutting lines of the workpiece are cut by the cutting blade. Thereby, after the cutting blade cuts all the cutting lines, the ultrasonic vibrator can be operated to sufficiently ultrasonically clean the cutting groove of the workpiece.

  The holding means may hold the workpiece in a state where it is submerged in the cutting fluid. As a result, the workpiece submerged in the cutting fluid is ultrasonically vibrated, so that the cutting waste in the cutting groove of the workpiece can be easily detached from the cutting groove and floated in the cleaning liquid. The cleaning effect can be enhanced.

  As described above, according to the present invention, the workpiece itself is ultrasonically vibrated in the vertical direction by the ultrasonic vibrator provided in the holding means, thereby existing in the cutting groove formed in the workpiece. It is possible to suitably clean and remove the cutting waste.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  First, an outline of the cleaning method according to the first embodiment of the present invention will be described. In the cleaning method according to the present embodiment, a workpiece on which one or more cutting grooves are formed by cutting is targeted for cleaning, and fine cutting chips clogged in the cutting grooves of the workpiece are preferably used from the cutting grooves. It aims to be removed. In order to achieve this object, in the cleaning method according to the present embodiment, an ultrasonic vibrator is installed in the holding means for holding the workpiece, and when the workpiece is cleaned, the holding means is vertically moved by the ultrasonic vibrator. The workpiece itself held in the holding means is vibrated in the vertical direction by ultrasonic vibration in the direction, and the cutting waste in the cutting groove is removed by ultrasonic cleaning.

  In the following, first, the principle and problems of the conventional cleaning method will be described with reference to FIG. 5, and then the principle of the cleaning method according to the present embodiment and the operation and effect thereof will be described with reference to FIG. To do. In the following description, an example of a semiconductor wafer in which cutting grooves are formed will be described as the workpiece to be cleaned. However, the workpiece of the present invention is not limited to such an example.

  FIG. 5 is a conceptual diagram illustrating the principle of a conventional cleaning method. As shown in FIG. 5, in the conventional cleaning method, cleaning water 2 (hereinafter referred to as “vibration cleaning water 2”) which is ultrasonically vibrated from an ultrasonic cleaning nozzle 1 provided with an ultrasonic vibrator (not shown). ) Is sprayed toward the wafer W, and the cleaning force is generated by the impact force or cavitation of the vibration cleaning water 2 on the wafer W to remove the cutting waste adhering to the surface of the wafer W. It is. At this time, the wafer W is placed on a holding means (not shown) with the front surface side on which the circuit pattern 5 is formed facing upward, and a wafer tape 6 is attached to the rear surface side. Yes. In addition, a plurality of cutting grooves 3 are formed in the vertical direction on the wafer W from the surface side by cutting in a cutting process which is a previous process.

  However, in the conventional cleaning method of FIG. 5, since the cutting grooves 3 formed on the wafer W are narrow and deep (for example, groove width: about 10 to 50 μm, depth: about 400 to 800 μm), the vibration cleaning water 2 The ultrasonic vibration added to is absorbed and attenuated by the wall surface of the cutting groove 3 and does not reach the bottom of the cutting groove 3 (see reference A). For this reason, there is a problem that the cutting waste 4 clogged at the bottom of the cutting groove 3 cannot be removed from the cutting groove 3. In the cut wafer W, the bottom of the cutting groove 3 is the place where the most cutting debris is present, and the above-described conventional cleaning method has a sufficient cleaning effect on the bottom of the cutting groove 3 which is the place to be cleaned most. It was not obtained.

  In addition, since the ultrasonic vibration of the jetted vibration cleaning water 2 is highly directional, there is a problem that the effective range of the cleaning power is narrow, and the cleaning power decreases as the distance from directly below the ultrasonic cleaning nozzle 1 increases. (See symbol B). Furthermore, depending on the material of the wafer W, there is a problem that the circuit pattern 5 formed on the surface of the wafer W may be damaged by the impact force or cavitation of the vibration cleaning water 2.

  Next, with reference to FIG. 1, the principle and operation effect of the cleaning method according to the present embodiment for solving the problems of the conventional cleaning method as described above will be described. FIG. 1 is a conceptual diagram illustrating the principle of the cleaning method according to the present embodiment.

  As shown in FIG. 1, in the cleaning method according to the present embodiment, holding means (not shown) (for example, a chuck table 15 of a dicing device 10 (see FIG. 2) described later) or a spinner table 31 of a spinner cleaning device 30 (see FIG. 1). 2) and the like) is placed and held with the surface on which the circuit pattern 5 is formed facing upward. The holding means is provided with an ultrasonic vibrator that ultrasonically vibrates the holding means in the vertical direction (vertical direction). When cleaning the wafer W, the ultrasonic vibrator vibrates in the vertical direction from the lower surface side of the wafer W through the holding means by vibrating the holding means in the vertical direction by the ultrasonic vibrator. Thus, the direction of the ultrasonic vibration excited on the wafer W is the same as the depth direction of the cutting groove 3 formed on the wafer W. The frequency of the ultrasonic vibration is, for example, 1 to 10 MHz, and the amplitude of the ultrasonic vibration is, for example, 5 to 50 μm. The frequency and amplitude vary depending on the type of workpiece, the cleaning conditions, and the like.

  In this way, by applying ultrasonic vibration from the lower surface side of the wafer W, impact force and cavitation are generated from the bottom of the cutting groove 3, so that the cutting waste 4 clogged at the bottom of the cutting groove 3 is peeled from below. As a result, a detergency that lifts up is generated (see symbol D). On the other hand, on the lower surface (back surface) side of the wafer W, the ultrasonic vibration transmitted to the wafer W is attenuated by the mass effect due to the presence of the wafer W in the upper portion (region indicated by the symbol F). The In this way, the cleaning action by ultrasonic vibration from the lower surface side of the wafer W acts intensively on the bottom of the cutting groove 3 in which the cutting waste 4 is clogged.

  As a result, the cutting waste 4 clogged at the bottom of the cutting groove 3 rises in the cutting groove 3 and is discharged from the cutting groove 3 and floats in the cleaning water film on the surface of the wafer W. (See symbol E). Further, the floating cutting waste 4 is discharged to the outside in the flow of the cleaning water without being deposited and adhered to the surface of the wafer W due to the vibration of the wafer W surface (upper surface) due to the ultrasonic vibration. Thus, in the cleaning method according to the present embodiment, the cutting waste 4 present at the bottom of the cutting groove 3 of the wafer W can be suitably taken out from the cutting groove 3 and removed.

  Further, in the cleaning method according to the present embodiment, since the holding unit that holds the wafer W is ultrasonically vibrated, the entire wafer W held by the holding unit can be simultaneously ultrasonically vibrated from the lower surface side. Therefore, there is no problem of directivity of ultrasonic vibration as in the case where the vibration cleaning water 2 is partially jetted onto the wafer W by the conventional cleaning method of FIG. Accordingly, there is an advantage that the effective range of the cleaning power is wide and the inside of the plurality of cutting grooves 3 on the entire surface of the wafer W can be cleaned simultaneously. Further, since the wafer W itself is ultrasonically vibrated from the lower surface side, the circuit pattern 5 formed on the surface of the wafer W is damaged by the impact force or cavitation of the vibration cleaning water 2 as in the above conventional cleaning method. There is also an advantage that it does not occur.

  Heretofore, the principle and operational effects of the cleaning method according to the present embodiment have been described. Hereinafter, an apparatus configuration for executing the cleaning method according to the present embodiment as described above and a cleaning operation thereof will be described in detail.

  First, an overall configuration of a dicing apparatus 10 that is an example of a cutting apparatus that executes the cleaning method according to the present embodiment will be described with reference to FIG. FIG. 2 is an overall perspective view showing the dicing apparatus 10 according to the present embodiment.

  As shown in FIG. 2, the dicing apparatus 10 includes, for example, a chuck table 15 that is an example of a holding unit that holds the wafer W, a cutting unit 20 that is a cutting unit that cuts the wafer W, and a cutting unit moving mechanism ( (Not shown), a chuck table moving mechanism (not shown), and a spinner cleaning device 30 are mainly provided.

  The wafer W is, for example, a silicon wafer having a plurality of circuit patterns 5 formed on the surface. On the surface of the wafer W, cutting lines (streets) for dividing the plurality of circuit patterns 5 are arranged in a lattice pattern. The wafer W is placed on the chuck table 15 in a state where, for example, a wafer tape 6 as an adhesive tape is affixed to the back side of the wafer W and is supported by the wafer ring 7 via the wafer tape 6.

  The chuck table 15 is, for example, a disk-shaped table for sucking and holding the wafer W placed on the upper surface thereof, and includes a vacuum chuck (not shown) on the upper surface side. The chuck table 15 vacuum-sucks and stably holds the wafer W placed on the vacuum chuck.

  The cutting unit 20 includes a ring-shaped cutting blade 22 attached to the tip of a spindle (not shown). The cutting unit 20 cuts the wafer W along a cutting line by cutting a cutting blade 22 rotated at a high speed by a spindle into the wafer W, thereby forming an extremely thin cutting groove 3.

  The cutting unit moving mechanism moves the cutting unit 20 in the Y-axis direction. The Y-axis direction is a horizontal direction orthogonal to the cutting direction (X-axis direction), and coincides with the axial direction of the spindle extending in the cutting unit 20. The cutting edge of the cutting blade 22 can be aligned with the cutting position (cutting line) of the wafer W by moving the cutting unit 20 in the Y-axis direction. Further, the cutting unit moving mechanism moves the cutting unit 20 also in the Z-axis direction (vertical direction). Thereby, the cutting depth of the cutting blade 22 with respect to the wafer W can be adjusted.

  The chuck table moving mechanism reciprocates the chuck table 15 holding the wafer W in the cutting direction (X-axis direction) during the cutting process so that the cutting edge of the cutting blade 22 acts on the wafer W along a linear locus. The chuck table moving mechanism can change the cutting direction by rotating the chuck table 15 in a horizontal plane.

  The spinner cleaning device 30 holds the wafer W after the cutting by holding means, and sprays a cleaning liquid (cleaning water or the like) on the surface of the wafer W while rotating the wafer W in a horizontal plane. The cutting waste adhering to the wafer W is cleaned and removed. Details of the configuration of the spinner cleaning apparatus 30 will be described later.

  The dicing apparatus 10 having the overall configuration described above has a grid pattern on the surface of the wafer W by relatively moving the cutting unit 20 and the chuck table 15 while cutting the cutting blade 22 rotating at high speed into the wafer W. A plurality of cutting lines (streets) arranged are cut to form the cutting grooves 3. Thereby, the wafer W can be diced and divided into a plurality of chips. Furthermore, the cut wafer or the like adhering to the wafer W is cleaned and removed by transporting the wafer W thus cut to the spinner cleaning device 30 and performing spinner cleaning.

  Next, with reference to FIG. 3, the structure and operation | movement for performing the washing | cleaning method concerning the said this embodiment using the chuck table 15 of the dicing apparatus 10 are demonstrated in detail. FIG. 3 is a side view showing configurations of the cutting unit 20 and the chuck table 15 in the dicing apparatus 10 according to the present embodiment.

  First, the configuration of the cutting unit 20 will be described. As shown in FIG. 3, the cutting unit 20 includes, for example, a cutting blade 22 attached to the tip of the spindle 24, a cutting fluid supply nozzle 26 that supplies cutting fluid to the cutting points of the cutting blade 22 and the wafer W, And a blade cover 28 disposed so as to cover the outer periphery of the cutting blade 22.

  The cutting blade 22 is an ultra-thin rotating cutting grindstone formed by bonding abrasive grains such as diamond with a bonding material, for example. This cutting blade 22 may be constituted by, for example, a so-called washer blade, or may be constituted by a hub blade integrated with a base portion. The cutting blade 22 is rotated at a high speed by a spindle 24 at, for example, 30,000 rpm.

  The cutting fluid supply nozzle 26 is an example of a cutting fluid supply unit that supplies the cutting fluid to the surface of the wafer W. In the present embodiment, for example, cutting fluid is supplied as the cutting fluid. The cutting fluid supply nozzle 26 is composed of, for example, a pair of linear nozzles opposed to each other on both sides (front side and back side) of the lower part of the cutting blade 22 with the cutting blade 22 interposed therebetween. The pair of cutting fluid supply nozzles 26 includes, for example, a plurality of injection ports (not shown) on the side facing the cutting blade 22, and from these injection ports, the lower side surface of the cutting blade 22 and the wafer W Inject and supply cutting water toward the processing point. In this way, by supplying cutting water from both sides of the cutting blade 22 by the pair of cutting fluid supply nozzles 26, the cutting blade 22 and the processing point are cooled at the time of cutting, and chipping occurs at the processing point. 22 can be prevented from being damaged. Further, the cutting water supplied from the cutting fluid supply nozzle 26 also functions as cleaning water at the time of ultrasonic cleaning processing of the wafer W by the chuck table 15 described later, details of which will be described later.

  The blade cover 28 is disposed so as to cover the outer periphery of the cutting blade 22 and protects the cutting blade 22, and cutting fluid and cutting debris accompanying cutting processing, broken pieces of the cutting blade 22, etc. are cut. It is prevented from scattering outside the unit 20.

  Next, the configuration of the chuck table 15 will be described. As shown in FIG. 3, the disc-shaped chuck table 15 has a concave portion 151 with a predetermined depth formed on the upper surface thereof. The recess 151 is, for example, a circular recess having a size enough to accommodate the wafer ring 7 that supports the wafer W. The depth of the recess 151 is such that when the wafer W having the wafer tape 6 attached to the back surface is placed in the recess 151 and filled with a liquid (for example, water), the surface (upper surface) of the wafer W is filled. It is deep enough to be submerged under the liquid surface 8. Further, a vacuum chuck (not shown) is disposed on the flat bottom surface of the recess 151 so that the wafer W placed thereon can be held by vacuum suction.

  By providing such a recess 151, for example, the cutting water supplied from the cutting fluid supply nozzle 26 of the cutting unit 20 can be stored in the recess 151. Accordingly, the chuck table 15 can hold the wafer W supported by the wafer ring 7 and the wafer tape 6 in a state where the wafer W is submerged in the cutting water. Further, the chuck table 15 is formed with a drain hole 152 communicating with the recess 151 so that the water stored in the recess 151 can be discharged to the outside.

  An ultrasonic transducer 16 is installed inside the disc-shaped chuck table 15. The ultrasonic transducer 16 has, for example, a disk shape that is smaller than the outer diameter of the chuck table 15 and at least larger than the outer diameter of the wafer W. As described above, the ultrasonic transducer 16 generates ultrasonic vibration having a frequency of, for example, 1 to 10 MHz and an amplitude of, for example, 5 to 50 μm, and ultrasonically vibrates the chuck table 15 in the vertical direction. Accordingly, the wafer W can be ultrasonically cleaned by ultrasonically vibrating the entire wafer W held on the chuck table 15 in a submerged state from the lower surface side in the vertical direction. Thus, in this embodiment, the chuck table 15 for cutting can also be used as a cleaning device for ultrasonically cleaning the wafer W.

  Next, a cutting operation and a cleaning operation using the cutting unit 20 and the chuck table 15 configured as described above will be described.

  At the time of cutting, as shown in FIG. 3A, the cutting unit 20 is lowered while supplying cutting water to the cutting blade 22 and the processing point by the cutting fluid supply nozzle 26, and the cutting edge of the cutting blade 22 rotating at high speed is obtained. The chuck table 15 is relatively moved in the cutting direction while cutting the wafer W from the surface of the wafer W, and the wafer W is cut along the cutting line. At the time of such cutting, the ultrasonic transducer 16 does not generate ultrasonic vibration, and therefore the ultrasonic cleaning process of the wafer W as described in FIG. 1 is not executed.

  On the other hand, as shown in FIG. 3B, the ultrasonic cleaning process of the wafer W is performed when the cutting unit 20 is separated from the wafer W and “the cutting process of the wafer W by the cutting blade 22 is not performed”. Executed. In this ultrasonic cleaning process, the ultrasonic vibrator 16 provided on the chuck table 15 is operated in a state where the wafer W is submerged in the water (the cutting water) stored in the recess 151 of the chuck table 15. Thus, the chuck table 15 is ultrasonically vibrated in the vertical direction, so that the wafer W is ultrasonically vibrated in the vertical direction from the lower surface side. Thereby, according to the principle described with reference to FIG. 1, the cutting waste existing in the cutting groove 3 of the wafer W can be suitably ultrasonically cleaned and removed. Further, by ultrasonically cleaning the wafer W in a submerged state, the cutting waste 4 is easily detached from the cutting groove 3 and floats in the water, so that the cleaning effect can be enhanced.

  In this ultrasonic cleaning process, for example, the cutting water supplied from the cutting fluid supply nozzle 26 and stored in the recess 151 of the chuck table 15 at the time of the cutting function functions as cleaning water for ultrasonic cleaning. To do. In this ultrasonic cleaning process, ultrasonic cleaning may be performed while supplying cleaning water to the surface of the wafer W by the cutting liquid supply nozzle 26 or a separate liquid supply means.

  The reason why such an ultrasonic cleaning process is performed when “the cutting of the wafer W by the cutting blade 22 is not performed” as described above is, for example, that the workpiece is a wafer made of a crystal material such as silicon. This is because, in the case of W or the like, if the workpiece is cut while being ultrasonically vibrated, there is a problem that chipping generated on the workpiece due to the cutting processing is increased.

  Therefore, in the present embodiment, the ultrasonic vibration cleaning process is not executed at the time of cutting with the cutting blade 22, and the ultrasonic cleaning process is performed when “the cutting of the wafer W by the cutting blade 22 is not performed”. To do.

  This “when the cutting of the wafer W by the cutting blade 22 is not performed” can be, for example, “when the cutting blade 22 moves between the cutting lines of the wafer W”. That is, when cutting a plurality of cutting lines of the wafer W using the same cutting blade 22, the cutting blade 22 is moved from the position of the cut cutting line to the start position of the next cutting target cutting line. There is a need. As described above, when the cutting blade 22 is moved between the cutting lines, since the cutting blade 22 is separated from the wafer W and no cutting process is performed, the ultrasonic cleaning process of the wafer W can be suitably executed.

  As an operation flow of the dicing apparatus 10 in this case, first, as shown in FIG. 3A, one or more cutting lines of the wafer W are cut by the cutting blade 22 (first step), and then As shown in FIG. 3B, the wafer W is moved downward by the ultrasonic transducer 16 during the period from the time when the cutting blade 22 is retracted from the last cut cutting line and moved to the start position of the next cutting line. Then, the cutting waste in the cutting groove 3 is ultrasonically cleaned (second step), and thereafter the ultrasonic vibration is stopped, and then again as shown in FIG. Thus, each process of cutting the next cutting line (third process) is repeated. By performing the ultrasonic cleaning process with such an operation flow, it is possible to efficiently clean the inside of the cutting groove 3 of the wafer W by sewing between the cutting processes of the plurality of cutting lines by the cutting blade 22.

  Another example of “when the cutting of the wafer W is not performed by the cutting blade 22” is, for example, “after the cutting blade 22 cuts all the cutting lines of the wafer W”. it can. That is, of course, after all the cutting lines of the wafer W are cut by the cutting blade 22, no cutting is performed. For this reason, the ultrasonic cleaning process of the wafer W can be suitably executed without causing chipping or the like on the wafer W after completion of all the cutting lines.

  The operation flow of the dicing apparatus 10 in this case is as follows. First, as shown in FIG. 3A, all cutting lines of the wafer W are cut by the cutting blade 22 (first step), and then FIG. ), After the cutting blade 22 is retracted from the last cut cutting line, the wafer W is ultrasonically vibrated from below by the ultrasonic vibrator 16 to ultrasonically remove the cutting waste in the cutting groove 3. Wash (second step). By performing ultrasonic cleaning at such timing, all the cutting grooves 3 formed by the cutting process by the cutting blade 22 are cleaned over a sufficient amount of time, and the cutting waste in all the cutting grooves 3 is obtained. 4 can be suitably removed.

  Furthermore, as another example of the timing of executing the ultrasonic cleaning process, for example, after cutting a plurality of parallel cutting lines constituting the first channel of the wafer W, the first channel of the wafer W that has been cut is processed. After performing ultrasonic cleaning of the cutting groove 3 and then cutting a plurality of parallel cutting lines constituting the second channel orthogonal to the first channel, the cutting grooves of the first and second channels of the wafer W are again formed. 3 ultrasonic cleaning may be performed.

  The configuration and operation for executing the cleaning method according to the present embodiment using the chuck table 15 and the cutting unit 20 provided in the cutting region in the dicing apparatus 10 have been described above. As described above, the ultrasonic vibration applied to the wafer W in the present embodiment is performed at a timing different from the cutting process in order to clean and remove the fine cutting chips clogged in the cutting groove 3 of the wafer W. This is different from the ultrasonic vibration that is performed simultaneously with the cutting process in order to smoothly perform the cutting process with the cutting blade as conventionally performed.

  Next, with reference to FIG. 4, the structure and operation | movement for performing the washing | cleaning method concerning this embodiment using the spinner washing | cleaning apparatus 30 of the dicing apparatus 10 are demonstrated in detail. FIG. 4 is a side view showing the configuration of the spinner cleaning device 30 in the dicing apparatus 10 according to the present embodiment.

  As shown in FIG. 4, the spinner cleaning apparatus 30 includes, for example, a spinner table 31 that holds the wafer W after cutting, a rotating shaft 32 that supports the spinner table 31, and a wafer W held on the spinner table 31. A cleaning liquid supply nozzle 33 for injecting and supplying a cleaning liquid (for example, cleaning water) to the surface, a support 35 for rotatably supporting the cleaning liquid supply nozzle 33 via an arm 34, and one end connected to the support 35 A rotating shaft 36 whose end is connected to an electric motor (not shown), a cleaning liquid supply source 38 for supplying a cleaning liquid to the cleaning liquid supply nozzle 33 via a hose 37, a valve 39 provided in the middle of the hose, Is provided.

  The spinner table 31 is an example of a holding unit that holds the wafer W in which the cutting groove 3 is formed by the cutting process. The spinner table 31 is, for example, a substantially disk-shaped table, and includes a vacuum chuck (not shown) made of a porous ceramic disk on the upper surface thereof. The spinner table 31 holds the wafer W after cutting by vacuum suction with its surface (circuit surface) facing upward. The spinner table 31 is connected to an electric motor (not shown) via a rotating shaft 32. Thereby, during the spinner cleaning, the spinner table 31 that holds the wafer W by suction can be rotated in a horizontal plane.

  Further, a concave portion 311 having a predetermined depth is formed on the upper surface of the spinner table 31 so as to be recessed like the concave portion 151 of the chuck table 15. The recess 311 is, for example, a circular recess having a size enough to accommodate the wafer ring 7 that supports the wafer W. The depth of the recess 311 is such that when the wafer W to which the wafer tape 6 is attached is placed in the recess 311 and the cleaning liquid (for example, cleaning water) is filled, the surface (upper surface) of the wafer W is liquid. It is deep enough to be submerged under the surface 9. The vacuum chuck is disposed on the flat bottom surface of the recess 311 so that the mounted wafer W can be sucked and held.

  By providing such a recess 311, for example, the cleaning water supplied from the cleaning liquid supply nozzle 33 can be stored in the recess 311, and the spinner table 31 is supported by the wafer ring 7 and the wafer tape 6. W can be held in a state of being submerged in the wash water.

  An ultrasonic transducer 40 is installed inside the disk-shaped spinner table 31. The ultrasonic transducer 40 has, for example, a disk shape that is smaller than the outer diameter of the spinner table 31 and at least larger than the outer diameter of the wafer W. As described above, the ultrasonic transducer 40 generates ultrasonic vibration having a frequency of, for example, 1 to 10 MHz and an amplitude of, for example, 5 to 50 μm, and ultrasonically vibrates the spinner table 31 in the vertical direction.

  The cleaning liquid supply nozzle 33 is an example of a cleaning liquid supply unit that supplies a cleaning liquid to the surface of the wafer W. In the present embodiment, for example, pure water is supplied as the cleaning liquid. The cleaning liquid supply nozzle 33 is connected to a cleaning liquid supply source 38 via a flexible hose 37. When the valve 39 is opened, cleaning water is supplied from the cleaning liquid supply source 38 to the cleaning liquid supply nozzle 33 at a predetermined pressure. The As a result, the cleaning liquid supply nozzle 33 sprays the cleaning water supplied from the cleaning liquid supply source 38 toward the surface of the wafer W.

  The cleaning liquid supply nozzle 33 can be rotated in a horizontal plane around the rotation shaft 36 by a rotation mechanism including the arm 34, the support 35, the rotation shaft 36, and an electric motor (not shown). It has become. Thus, at the time of cleaning, the cleaning liquid supply nozzle 33 swings above the wafer W and can supply cleaning water to the entire surface of the wafer W substantially uniformly.

  In addition to the above-described parts, the spinner cleaning apparatus 30 includes an air supply unit that injects and supplies air for drying the wafer W after cleaning, a housing that covers the cleaning region, an openable / closable shutter, and the like (both shown in FIG. (Not shown).

  Next, the cleaning operation (spinner cleaning processing operation and ultrasonic cleaning processing operation) of the spinner cleaning device 30 configured as described above will be described.

  When the spinner cleaning process is performed, the spinner cleaning device 30 holds the wafer W after cutting with the spinner table 31 with the surface facing upward, and rotates the held wafer W while rotating the held wafer W. Cleaning water is sprayed onto the surface of the wafer W from the cleaning liquid supply nozzle 33 that is swung by the mechanism. Thus, contaminants such as cutting dust adhering to the wafer W can be cleaned and removed by the action of the water pressure of the cleaning water and the centrifugal force.

  Further, the spinner cleaning apparatus 30 can execute the ultrasonic cleaning process by operating the ultrasonic vibrator 40 provided in the spinner table 31 as well as the general spinner cleaning process.

  Specifically, the spinner cleaning apparatus 30, when performing this ultrasonic cleaning process, cleans the cleaning liquid that is swung by the rotating mechanism with respect to the surface of the wafer W held in a submerged state on the spinner table 31. While ejecting and supplying cleaning water from the supply nozzle 33, the spinner table 31 is ultrasonically vibrated in the vertical direction from the ultrasonic transducer 40. As a result, the entire wafer W held on the spinner table 31 is ultrasonically vibrated in the vertical direction from the lower surface side, and is present in the cutting groove 3 of the wafer W according to the principle described with reference to FIG. The cutting waste 4 can be removed from the cutting groove 3 by ultrasonic cleaning of the cutting waste 4.

  By this ultrasonic cleaning process, the cutting waste 4 in the cutting groove 3 that could not be removed by the general spinner cleaning process can be suitably cleaned and removed. In addition, by ultrasonically cleaning the wafer W in the submerged state, the cutting waste 4 is easily detached from the cutting groove 3 and floats in the water, so that the cleaning effect can be enhanced.

  Such an ultrasonic cleaning process in the spinner cleaning device 30 may be performed while the spinner table 31 is rotated, or may be performed in a state where the spinner table 31 is stopped. Even if the ultrasonic cleaning is performed with the spinner table 31 stopped rotating, the wafer W can be suitably cleaned if the entire surface of the wafer W is submerged in the cleaning water supplied from the cleaning liquid supply nozzle 33. is there.

  Accordingly, as a cleaning procedure by the spinner cleaning device 30, for example, (1) after executing the spinner cleaning process, the rotation of the spinner table 31 is stopped, the operation of the ultrasonic transducer 40 is started, and the ultrasonic cleaning process is performed. (2) A method of executing the spinner cleaning process by stopping the operation of the ultrasonic transducer 40 and rotating the spinner table 31 after executing the ultrasonic cleaning process, and (3) rotating the spinner table 31. Any of the methods of operating the ultrasonic transducer 40 while performing the spinner cleaning process and the ultrasonic cleaning process at the same time can be implemented.

  The cleaning method according to the present embodiment and the dicing apparatus 10 and the spinner cleaning apparatus 30 that execute the cleaning method have been described above in detail. According to the cleaning method of the present embodiment, the wafer W itself is ultrasonically vibrated in the vertical direction from the lower surface side by the ultrasonic vibrators 16 and 40 provided in the holding means such as the chuck table 15 or the spinner table 31. Thereby, an impact force or cavitation is generated from the bottom of the cutting groove 3 of the wafer W, and a cleaning force is generated so that the cutting waste 4 clogged in the bottom of the cutting groove 3 is peeled off from below and lifted up. it can. For this reason, even fine cutting waste 4 clogged at the bottom of the cutting groove 3 of the wafer W can be suitably removed from the cutting groove 3. Therefore, in the die bonding process, which is a subsequent process of the cleaning process, when the divided chips are picked up, cutting chips do not fall from the chips and foreign substances are not mixed into the production line. Occurrence can be prevented.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above embodiment, the example of the semiconductor wafer W has been described as the workpiece, but the present invention is not limited to such an example. Workpieces include, for example, various semiconductor wafers, CSP substrates, GPS substrates, semiconductor substrates such as package substrates such as BGA substrates, sapphire substrates, glass materials, ceramic materials, metal materials, synthetic resin materials such as plastics, or An electronic material substrate for forming a magnetic head, a laser diode head, or the like, or a substrate on which a plurality of imaging elements such as a CCD or C-MOS are formed may be used. Further, the shape of the workpiece is not limited to a substantially disk shape, and may be an arbitrary shape such as a substantially rectangular plate shape.

  Moreover, although the said embodiment gave and demonstrated the example of the dicing apparatus 10 as a cutting device which performs the cleaning method of this invention, this invention is not limited to this example. For example, an apparatus for cutting a workpiece using a cutting means such as a cutting blade and a holding means for holding the workpiece may be, for example, various cutting apparatuses that perform cutting other than dicing. May be.

  In the above-described embodiment, the example of the pair of cutting fluid supply nozzles 26 that supply the cutting fluid from both sides of the cutting blade 22 as the cutting fluid supply means included in the cutting apparatus has been described. It is not limited to such an example. For example, in addition to the cutting fluid supply nozzle 26 or in place of the cutting fluid supply nozzle 26, an outer peripheral nozzle disposed opposite to the outer peripheral surface of the cutting blade 22 is provided, and the outer peripheral surface of the cutting blade 22 is provided from the outer peripheral nozzle. The cutting fluid may be sprayed and supplied toward the head.

  Moreover, although the said embodiment gave and demonstrated the example of the spinner washing | cleaning apparatus 30 provided in the dicing apparatus 10 as a washing | cleaning apparatus which performs the washing | cleaning method of this invention, this invention is not limited to this example. For example, a cleaning device other than the spinner cleaning device 30 may be used as long as it is a cleaning device capable of performing the ultrasonic cleaning process. Further, the cleaning apparatus of the present invention is not limited to the cleaning apparatus mounted on the cutting apparatus such as the dicing apparatus 10 as described above. For example, the cleaning apparatus mounted on various processing apparatuses such as a grinding apparatus and a polishing apparatus, , It may be configured by a dedicated cleaning device installed alone.

  Further, the cutting fluid and the cleaning fluid are not limited to the above example of water, and may be any liquid as long as the fluid is suitable for the cutting fluid or the cleaning fluid.

  The present invention can be applied to a cleaning method and a cleaning apparatus for suitably removing cutting chips present in a cutting groove formed on the surface of a workpiece.

It is a conceptual diagram explaining the principle of the washing | cleaning method concerning the 1st Embodiment of this invention. It is a whole perspective view which shows the dicing apparatus concerning the embodiment. It is a side view which shows the structure of the cutting unit and chuck table in the dicing apparatus concerning the embodiment. It is a side view which shows the structure of the spinner washing | cleaning apparatus in the dicing apparatus concerning the embodiment. It is a conceptual diagram explaining the principle of the conventional cleaning method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Cutting groove 4 Cutting waste 5 Circuit pattern 6 Wafer tape 7 Wafer ring 10 Dicing apparatus 15 Chuck table 16 Ultrasonic vibrator 20 Cutting unit 22 Cutting blade 24 Spindle 26 Cutting fluid supply nozzle 28 Blade cover 30 Spinner cleaning apparatus 31 Spinner table 33 Cleaning liquid supply nozzle 40 Ultrasonic vibrator 151 Concave part 311 Concave part W Wafer

Claims (5)

Holding means for holding the workpiece with the surface facing upward, a cutting blade for cutting the workpiece held by the holding means, and a cutting fluid for supplying cutting fluid to the surface of the workpiece In a cutting apparatus having a supply means, a cleaning method is provided for cleaning a workpiece, on which a cutting groove is formed on a surface by cutting with the cutting blade, in order to remove cutting chips present in the cutting groove. :
The holding means has a recessed portion capable of accommodating the workpiece on its upper surface, and can store the cutting fluid supplied from the cutting fluid supply means as a cleaning fluid in the recessed portion,
An ultrasonic transducer for ultrasonically vibrating the holding means in the same direction as the depth direction of the cutting groove of the workpiece held by the holding means is provided on the lower side of the concave portion of the holding means. And
While the cutting fluid is supplied to the workpiece as the cleaning fluid by the cutting fluid supply means , the surface is facing upward in a state where the workpiece is submerged in the cleaning fluid in the recess by the holding means. Held in a state of being immersed in the cleaning liquid so as to generate a cleaning force that peels and lifts up the cutting waste clogged at the bottom of the cutting groove by the ultrasonic vibrator. A cleaning method, wherein the workpiece is ultrasonically vibrated in the same direction as the depth direction of the cutting groove to clean and remove the cutting waste in the cutting groove. 2. The cleaning method according to claim 1, wherein when the workpiece is not cut by the cutting blade, the cutting waste in the cutting groove is cleaned and removed. Wherein by the cutting blade and when cutting of the workpiece is not being performed, characterized in that said cutting blade said it is time to move between the cutting line of the workpiece, according to claim 2 Cleaning method. And when the cutting of the workpiece by the cutting blade is not being performed, characterized in that the is after all the cutting lines of the workpiece is cut by a cutting blade, in claim 2 The cleaning method described. Holding means for holding the workpiece with the surface facing upward, a cutting blade for cutting the workpiece held by the holding means, and a cutting fluid for supplying cutting fluid to the surface of the workpiece A cleaning device provided in a cutting device having a supply means, and for cleaning a workpiece, on which a cutting groove is formed on a surface by cutting with the cutting blade, in order to remove cutting chips existing in the cutting groove Because:
The holding means has a recessed portion capable of accommodating the workpiece on its upper surface, and can store the cutting fluid supplied from the cutting fluid supply means as a cleaning fluid in the recessed portion,
The bottom side of the recess of the retaining means, the ultrasonic transducer is provided to the ultrasonic vibrations of the holding unit in the depth direction in the same direction of the cutting groove of the workpiece held by the holding means And
While the cutting fluid is supplied to the workpiece as the cleaning fluid by the cutting fluid supply means , the surface is facing upward in a state where the workpiece is submerged in the cleaning fluid in the recess by the holding means. Held in a state of being immersed in the cleaning liquid so as to generate a cleaning force that peels and lifts up the cutting waste clogged at the bottom of the cutting groove by the ultrasonic vibrator. A cleaning apparatus, wherein the workpiece is ultrasonically vibrated in the same direction as the depth direction of the cutting groove to clean and remove the cutting waste in the cutting groove.

Images