JP6078297B2 - Processing equipment - Google Patents

Description

  The present invention relates to a processing device such as a cutting device, a laser processing device, or a grinding device for processing a workpiece such as a wafer.

  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. Then, individual semiconductor devices are manufactured by dicing the semiconductor wafer along a street with a processing apparatus such as a cutting apparatus or a laser processing apparatus. In addition, in order to reduce the size and weight of a semiconductor device, the semiconductor wafer is cut along a street and divided into individual devices, and the back surface of the semiconductor wafer is ground by a grinder to a predetermined thickness. Is formed.

  For example, a processing device such as a cutting device or a laser processing device includes a holding unit having a holding table for holding a workpiece such as a wafer, a processing unit for processing the workpiece held by the holding unit, A machining feed means for machining and feeding the holding means and the machining means in the machining feed direction is provided. A holding table that constitutes a holding unit that holds a workpiece in such a processing apparatus includes a holding area that holds the workpiece by suction and a frame that has an outer peripheral area surrounding the holding area.

  The frame constituting the holding table constructed in this way is formed of a metal material such as stainless steel in order to set the origin position by electrical conduction with the cutting blade constituting the cutting means of the cutting device. (For example, refer to Patent Document 1).

JP 2005-142202 A

  However, in recent years, in order to improve productivity in semiconductor device manufacturing, the diameter of wafers tends to increase from 300 mm to 450 mm, and it is necessary to increase the diameter of the holding table for holding the wafer accordingly. is there. The weight of the holding table corresponding to a wafer having a diameter of 300 mm is about 10 kg, but the weight of the holding table corresponding to a wafer having a diameter of 450 mm exceeds 20 kg. When processing a wafer, it is replaced with an optimum holding table corresponding to the type of wafer. However, as described above, if the weight of the holding table exceeds 20 kg, it is difficult to attach and detach the holding table alone. There's a problem.

  The present invention has been made in view of the above-mentioned facts, and a main technical problem thereof is to provide a processing apparatus having a holding means having a holding table that is lightweight and easy to attach and detach.

In order to solve the main technical problem, according to the present invention, a holding means for holding a workpiece, a processing means for processing the workpiece held by the holding means, the holding means, and the processing means In a processing apparatus comprising a processing feed means for processing and feeding in the processing feed direction relatively,
The holding means includes a holding table having a suction area for sucking and holding a workpiece and an outer peripheral area surrounding the suction area, and a support base for detachably supporting the holding table and transmitting a suction force to the suction area. It consists of a stand and
The holding table is composed of porous ceramic, plating layer in a region other than the suction region that has been subjected machining apparatus is provided.

Further, the upper surface of the outer peripheral region is formed with a predetermined step from the upper surface of the suction region, and a metal ring having a thickness corresponding to the step and fitted to the outer periphery of the suction region is formed on the upper surface of the plating layer in the outer peripheral region. It is arranged.

Since the holding table constituting the holding means for holding the workpiece in the processing apparatus according to the present invention is made of porous ceramics, it is extremely light compared to a conventionally used stainless steel holding table, A single worker can easily perform the attaching / detaching operation.
The holding table is provided with a plating layer in a region excluding the suction region, and the upper surface of the outer peripheral region of the suction region is formed with a predetermined step from the upper surface of the suction region, and has a thickness corresponding to the step. Since the metal ring fitted to the outer periphery of the suction region is disposed on the upper surface of the plating layer in the outer periphery region, when applied to a cutting device, it is electrically energized with a cutting blade constituting the cutting means. The origin position can be set.

The perspective view of the cutting device as a processing apparatus comprised according to this invention by this invention. The perspective view which decomposes | disassembles and shows the holding table of the holding means with which the cutting apparatus shown in FIG. 1 is equipped. Sectional drawing of the holding means with which the cutting apparatus shown in FIG. 1 is equipped. Explanatory drawing of the method of coat | covering a plating layer in the area | region except the suction area | region of the holding table which comprises the holding means shown in FIG. 2 and FIG. Explanatory drawing which shows the other method of coat | covering a plating layer in the area | region except the suction area | region of the holding table which comprises the holding means shown in FIG. 2 and FIG. The perspective view which shows the state which stuck the semiconductor wafer as a to-be-processed object on the surface of the dicing tape with which the cyclic | annular flame | frame was mounted | worn.

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

FIG. 1 is a perspective view of a cutting device as a processing device configured according to the present invention.
The cutting apparatus shown in FIG. 1 includes a stationary base 2 and a workpiece that holds a wafer, which is a workpiece, disposed on the stationary base 2 so as to be movable in a direction indicated by an arrow X that is a machining feed direction. An object holding mechanism 3, a spindle support mechanism 6 disposed on the stationary base 2 so as to be movable in a direction indicated by an arrow Y that is an indexing feed direction (a direction perpendicular to a direction indicated by an arrow X that is a processing feed direction); A spindle unit 7 serving as a cutting means (processing means) is provided on the spindle support mechanism 6 so as to be movable in a direction indicated by an arrow Z that is a cutting feed direction.

  The workpiece holding mechanism 3 includes a holding means 4 that holds a wafer as a workpiece, and a holding table support mechanism 5 that supports the holding means 4 and moves it in a machining feed direction indicated by an arrow X. . The holding means 4 will be described in detail later.

  Continuing the description with reference to FIG. 1, the holding table support mechanism 5 includes a pair of guide rails 51, 51 disposed on the stationary base 2 in parallel along the machining feed direction indicated by the arrow X, A movable base 52 that is disposed on the guide rails 51 and 51 so as to be movable in the machining feed direction indicated by the arrow X and supports the holding means 4, and the movable base 52 along the pair of guide rails 51 and 51. A processing feed means 53 for moving is provided.

  The movable base 52 is formed in a rectangular shape, and guided grooves 521 and 521 that fit the pair of guide rails 51 and 51 are formed on the lower surface thereof. By fitting the guided grooves 521 and 521 to the pair of guide rails 51 and 51, the movable base 52 is disposed so as to be movable along the pair of guide rails 51 and 51.

  The processing feed means 53 includes a male screw rod 531 disposed in parallel between the pair of guide rails 51 and 51, and a drive source such as a servo motor 532 for rotationally driving the male screw rod 531. . One end of the male screw rod 531 is rotatably supported by a bearing block 533 fixed to the stationary base 2, and the other end is connected to the output shaft of the servo motor 532. The male screw rod 531 is screwed into a female screw 522 formed at the center of the moving base 52. Accordingly, when the male screw rod 531 is driven to rotate forward and reversely by the servo motor 532, the moving base 52 is moved along the guide rails 51 and 51 in the machining feed direction indicated by the arrow X.

Next, the holding means 4 will be described with reference to FIGS.
The holding means 4 shown in FIGS. 2 and 3 is rotatably supported by a cylindrical support cylinder 55 disposed on the upper surface of the moving base 52 via a bearing 56 as shown in FIG. As shown in FIGS. 2 and 3, the holding means 4 rotatably supported by the support cylinder 55 as described above includes the columnar support base 41 and the holding means disposed on the upper surface of the support base 41. It consists of a table 42. The support base 41 is formed of a metal material such as stainless steel, and a circular fitting recess 411 is provided on the upper surface thereof. As shown in FIG. 3, the support base 41 is provided with a suction passage 413 that opens into the fitting recess 411. The suction passage 413 communicates with suction means (not shown). Accordingly, when a suction means (not shown) is operated, a negative pressure is applied through the suction passage 413.

  2 to 3, the holding table 42 constituting the holding means 4 is formed in a disc shape as a whole, and includes a suction area 421 for sucking and holding a workpiece, and the suction area 421. In addition to having an outer peripheral region 422 that surrounds, a cylindrical bottom portion 423 that protrudes downward from the center of the lower portion and fits into a fitting recess 411 provided in the support base 41 is provided. A communication path 424 that communicates with a suction path 413 provided in the support base 41 in a state of being fitted into a fitting recess 411 provided in the support base 41, in the cylindrical bottom portion 423 constituting the holding table 42. Is formed. Further, the holding table 42 has a radial suction path 425 having one end communicating with a communication path 424 formed in the cylindrical bottom 423 and extending in the radial direction, and is formed concentrically with the suction path 413 and intersects with the radial suction path 425. A plurality of circular suction paths 426 formed in this manner are provided.

  The holding table 42 configured as described above is formed of porous ceramics having a pore size of 10 to 30 μm and a porosity of 40% in the illustrated embodiment. The holding table 42 formed of the porous ceramics is made of alumina ceramics having a particle size of 30 to 60 μm and a volume ratio of 70%, frit having a particle diameter of 5 μm or less and a volume ratio of 15%, and a volume ratio of 15%. It can be produced by kneading and molding an organic adhesive and firing at 1100 ° C. for 5 hours. Since the holding table 42 formed in this way is made of porous ceramics having a porosity of 40% with alumina ceramics having a specific gravity of 3.9, which is smaller than the specific gravity 7 of conventionally used stainless steel, The weight is about 1/3 of a stainless steel holding table.

The holding table 42 formed as described above is provided with a plating layer 427 in a region excluding the suction region 421. Here, a method of coating the plating layer 427 in the area excluding the suction area 421 of the holding table 42 will be described with reference to FIG.
As shown in FIG. 4B, a masking tape 428 is attached to the suction area 421 of the holding table 42 shown in FIG. At this time, the communication path 424 formed in the cylindrical bottom 423 is also masked. By applying electroless nickel plating to the holding table 42 masked in the suction area 421 and the communication path 424 in this way, a nickel plating layer 427 is formed in the area excluding the suction area 421 as shown in FIG. It is formed. The plating layer 427 is preferably formed so as to penetrate about 1 mm particularly in the outer peripheral region 422.

Next, another embodiment of the holding table 42 will be described with reference to FIG.
In the holding table 42 in the embodiment shown in FIG. 5, the upper surface of the outer peripheral region 422 is formed with a predetermined step 422 a from the upper surface of the suction region 421 as shown in FIG. Then, a masking tape 428 is attached to the suction area 421 as shown in FIG. At this time, the communication path 424 formed in the cylindrical bottom 423 is also masked. By applying electroless nickel plating to the holding table 42 masked in the suction area 421 and the communication path 424 in this way, a nickel plating layer 427 is formed in the area excluding the suction area 421 as shown in FIG. It is formed. Then, as shown in FIGS. 5C and 5D, a metal ring 429 made of stainless steel or the like having a thickness corresponding to the step 422a and fitted to the outer periphery of the suction region is formed in the outer peripheral region 422. Arrange.

  The holding means 4 on which the holding table 42 configured as described above is mounted on the support base 41 is configured to be appropriately rotated by a rotation driving means (not shown). Further, the base portions of the two clamps 43 are attached to the upper surface of the outer peripheral portion of the support base 41 constituting the holding means 4 by appropriate fixing means. A cover table 57 is disposed on the upper end of the support cylinder 55 that rotatably supports the support base 41 constituting the holding means 4.

  Returning to FIG. 1 and continuing the description, the spindle support mechanism 6 includes a pair of guide rails 61 and 61 disposed on the stationary base 2 in parallel along the index feed direction indicated by the arrow Y, and the guide A movable support base 62 is provided on the rails 61 and 61 so as to be movable in the direction indicated by the arrow Y. The movable support base 62 includes a movement support portion 621 that is movably disposed on the guide rails 61, 61, and a mounting portion 622 that is attached to the movement support portion 621. A pair of guided grooves 621 a and 621 a that are fitted to the guide rails 61 and 61 are formed on the lower surface of the moving support portion 621. By fitting the guided grooves 621 a and 621 a to the guide rails 61 and 61, The movable support base 62 is configured to be movable along the guide rails 61 and 61. The mounting portion 622 is provided with a pair of guide rails 622a and 622a extending in the direction indicated by the arrow Z on one side surface in parallel.

  The spindle support mechanism 6 in the illustrated embodiment includes index feed means 63 for moving the movable support base 62 along the pair of guide rails 61 and 61 in the index feed direction indicated by the arrow Y. The index feeding means 63 includes a male screw rod 631 disposed in parallel between the pair of guide rails 61, 61, and a drive source such as a pulse motor 632 for rotationally driving the male screw rod 631. One end of the male screw rod 631 is rotatably supported by a bearing block (not shown) fixed to the stationary base 2, and the other end is connected to the output shaft of the pulse motor 632. The male screw rod 631 is screwed into a female screw hole formed in a female screw block (not shown) provided on the lower surface of the central portion of the moving support portion 621 constituting the movable support base 62. Therefore, when the male screw rod 631 is driven to rotate forward and reversely by the pulse motor 632, the movable support base 62 is moved along the guide rails 61 and 61 in the index feed direction indicated by the arrow Y.

  The spindle unit 7 in the illustrated embodiment includes a unit holder 71, a spindle housing 72 attached to the unit holder 71, and a rotating spindle 73 that is rotatably supported by the spindle housing 72. The unit holder 71 is provided with a pair of guided grooves 71a and 71a slidably fitted to a pair of guide rails 622a and 622a provided in the mounting portion 622. The guided grooves 71a and 71a By being fitted to the guide rails 622a and 622a, the guide rails 622a and 622a are supported so as to be movable in the infeed direction indicated by the arrow Z. The rotary spindle 73 is disposed so as to protrude from the tip of the spindle housing 72, and a cutting blade 74 is attached to the tip of the rotary spindle 73. The cutting blade 74 is provided with an annular cutting edge having a thickness of 15 to 30 μm formed by solidifying diamond abrasive grains with nickel plating on the outer peripheral side surface of a disk-shaped base made of aluminum. The rotary spindle 73 on which the cutting blade 74 is mounted is driven to rotate by a drive source such as a servo motor 75. A cutting water supply nozzle 76 that supplies cutting water to a cutting portion by the cutting blade 74 is disposed on both sides of the cutting blade 74. An image pickup means 77 for picking up an image of the work piece held on the chuck table 4 and detecting a region to be cut by the cutting blade 74 is provided at the tip of the spindle housing 72. The imaging means 77 is composed of optical means such as a microscope and a CCD camera, and sends the captured image signal to a control means (not shown).

  The spindle unit 7 in the illustrated embodiment includes a cutting feed means 78 for moving the holder 71 along the pair of guide rails 622a and 622a in the direction indicated by the arrow Z. The cutting feed means 78 includes a male screw rod (not shown) disposed between the guide rails 622a and 622a and a pulse for rotationally driving the male screw rod, similarly to the processing feed means 53 and the index feed means 63. A drive source such as a motor 782 is included, and a male screw rod (not shown) is driven to rotate forward and backward by a pulse motor 782, whereby the unit holder 71, the spindle housing 72, and the rotary spindle 73 are moved along the guide rails 622a and 622a with arrows. Move in the infeed direction indicated by Z.

The cutting apparatus in the illustrated embodiment is configured as described above, and the operation thereof will be described below.
FIG. 6 shows a semiconductor wafer as a wafer which is a workpiece to be cut by the above-described cutting apparatus. A semiconductor wafer 10 shown in FIG. 6 is made of a silicon wafer. A surface 10a is formed with a lattice-like street 101, and devices 102 are formed in a plurality of regions partitioned by the lattice-like street 101. ing. The semiconductor wafer 10 thus configured is attached to the surface of the dicing tape T having the back surface 10b attached to the annular frame F.

  When the semiconductor wafer 10 described above is cut along the street 101, a holding table 42 suitable for cutting the semiconductor wafer 10 made of silicon wafer is selected, and the cylindrical bottom 423 is supported on a support base as shown in FIG. It is fitted and fitted in a fitting recess 411 provided in 41. At this time, since the holding table 42 is formed of porous ceramics as described above, the weight of the holding table 42 is about 1/3 of that of a conventionally used stainless steel holding table. The attachment / detachment work can be performed.

  In this way, when the holding table 42 suitable for cutting the semiconductor wafer 10 made of silicon wafer is mounted on the support base 41, a setup process for setting the origin position of the cutting blade 74 is performed. In this setup process, the holding table 42 constituting the holding means 4 is moved to a cutting area by the cutting blade 74, and the outer peripheral area 422 of the holding table 42 is positioned directly below the cutting blade 74. Then, the cutting feed means 78 is actuated to lower the cutting blade 74 to detect when the outer periphery of the cutting blade 74 contacts the outer peripheral region 422 of the holding table 42, and the position of the cutting blade 74 at that time is detected. Set as origin. At this time, since the plating table 427 made of nickel is formed in the holding table 42 except for the suction area 421, the detection current is energized when the cutting blade 74 comes into contact with the plating layer 427 covered by the outer peripheral area 422. Therefore, contact between the upper surface of the holding table 42 and the cutting blade 74 can be detected.

  As shown in FIG. 5, the outer peripheral region 422 is formed with the suction region 421 and the predetermined step 422 a as the holding table 42, and after the nickel plating layer 427 is formed in the region excluding the suction region 421 as described above, A metal ring 429 having a thickness corresponding to 422a and fitted to the outer periphery of the suction region can be used for a long time.

  Next, as shown in FIG. 6, the dicing tape T side of the semiconductor wafer 10 attached to the dicing tape T attached to the annular frame F is placed on the holding table 42 constituting the holding means 4. The annular frame F is fixed by the clamp 43. When the suction means (not shown) is operated, negative pressure acts on the suction passage 413 provided in the support base 41, the communication passage 424 provided in the holding table 42, the radial suction passage 425, and the circular suction passage 426 (see FIG. 3). As a result, the holding table 42 is formed of porous ceramics as described above, and the plated layer 427 made of nickel is formed in the area excluding the suction area 421, so that a suction force acts on the suction area 421 and dicing is performed. The semiconductor wafer 10 is sucked and held via the tape T (wafer holding step).

  When the wafer holding process described above is performed, the processing feeding means 53 is operated to move the holding means 4 to a position immediately below the image pickup means 77. When the holding unit 4 is positioned immediately below the image pickup unit 77, an alignment operation for detecting a processing region to be cut of the semiconductor wafer 10 is executed by the image pickup unit 77 and a control unit (not shown). That is, the imaging unit 77 and the control unit (not shown) are images such as pattern matching for aligning the street 101 formed in a predetermined direction of the semiconductor wafer 10 with the cutting blade 74 that cuts along the street 101. Execute the process and perform alignment of the machining area to be cut. Similarly, alignment of the machining area to be cut is performed on the street 101 formed in the semiconductor wafer 10 and extending in a direction orthogonal to the predetermined direction (alignment process).

  Thereafter, the holding means 4 is moved to a cutting region below the cutting blade 74, the cutting blade 74 is rotated in a predetermined direction, and a predetermined amount is cut and fed in the direction indicated by the arrow Z. Position it at the position where it reaches the dicing tape T. Then, the holding means 4 holding the semiconductor wafer 10 by suction is moved at a predetermined cutting feed speed in the direction indicated by the arrow X which is the cutting feed direction. As a result, the semiconductor wafer 10 held on the holding table 42 constituting the holding means 4 is cut along the predetermined street 101 by the cutting blade 74 (cutting process). When performing this cutting process, cutting water is sprayed from the cutting water supply nozzle 76 toward the side surface of the cutting blade 74.

  When the semiconductor wafer 10 is cut along the predetermined street 101 as described above, the holding means 4 is indexed and fed in the direction indicated by the arrow Y in FIG. 1 to perform the above-described cutting process. When the cutting process is performed along all the streets extending in the predetermined direction of the semiconductor wafer 10, the holding means 4 is rotated 90 degrees to extend in a direction orthogonal to the predetermined direction of the semiconductor wafer 10. By performing the cutting process along the streets 101, all the streets 101 formed in a lattice shape on the semiconductor wafer 10 are cut and divided into individual devices 102. The divided devices 102 do not fall apart due to the action of the dicing tape T, and the wafer state supported by the annular frame F is maintained. The individual semiconductor chips thus divided are transported to the next process in a state where they are adhered to a dicing tape T mounted on an annular frame F.

  Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to the embodiment, and various modifications are possible within the scope of the gist of the present invention. For example, in the above-described embodiment, an example in which the present invention is applied to a cutting apparatus that cuts the semiconductor wafer 10 along the street 101 has been shown. However, the present invention is widely applied to a processing apparatus such as a laser processing apparatus or a grinding apparatus. be able to.

2: Stationary base 3: Workpiece holding mechanism 4: Holding means 41: Support base 42: Holding table 5: Holding table support mechanism 53: Processing feed means 6: Spindle support mechanism 63: Indexing feed means 7: Spindle unit 72: spindle housing 73: rotating spindle 74: cutting blade 77: imaging means 78: cutting feed means 10: semiconductor wafer F: annular frame T: dicing tape

Claims (1)

Holding means for holding the workpiece, processing means for processing the workpiece held by the holding means, and processing feed means for processing and feeding the holding means and the processing means in the processing feed direction relatively In a processing apparatus comprising:
The holding means includes a holding table having a suction area for sucking and holding a workpiece and an outer peripheral area surrounding the suction area, and a support base for detachably supporting the holding table and transmitting a suction force to the suction area. It consists of a stand and
The holding table is made of porous ceramics, and a plating layer is applied to an area excluding the suction area ,
The upper surface of the outer peripheral region is formed with a predetermined step from the upper surface of the suction region, and a metal ring having a thickness corresponding to the step and fitted to the outer periphery of the suction region is the upper surface of the plating layer in the outer peripheral region A processing apparatus disposed in

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