JP5214324B2 - Cutting equipment - Google Patents

Description

  The present invention relates to a cutting apparatus that includes a chuck table that holds a workpiece and a cutting means that is rotatably mounted with a hub blade that cuts the workpiece held on the chuck table.

  In general, a cutting device called a dicer has a flange mount attached to the tip of a spindle, and a cutting blade having a thin cutting edge (grindstone) is attached to the flange mount and fixed with a nut to form an IC or LSI. In the field of cutting silicon wafers, ceramic substrates such as lithium niobate (LN) on which optical waveguides are formed, resin substrates, glass plates, etc., and dividing them into individual LSI chips, electronic devices, or optical devices It is used.

  A cutting blade used in a cutting apparatus is called a hub blade. This hub blade is configured by electrodepositing a grindstone portion in which diamond abrasive grains are dispersed in a nickel base material on the outer periphery of a hub base having a circular hub formed for easy handling.

  The hub base is formed in order to facilitate handling of a thin grindstone part having a thickness of 100 μm or less, and the grindstone part is formed on the outer peripheral part of one side of the hub base. The grindstone is consumed with the cutting process, and when the protrusion from the hub base (blade tip protruding amount) is not consumed, it is replaced with a new hub blade.

  When the hub blade is replaced, it is necessary to make various pre-processing adjustments before actually performing the cutting process, such as dressing / pre-cutting to make the blade round and sharp, and hairline adjustment to adjust the cutting position. .

Although it is considered possible to extend the life of the hub blade and reduce the replacement frequency of the blade by increasing the blade tip advancement amount, in fact, if the blade tip extension amount is too large, the rigidity of the grindstone will decrease. Cutting defects such as meandering where the grindstone bends during cutting work occur. Accordingly, a predetermined amount of blade tip is usually determined in consideration of the amount of wear depending on the type of hub blade.
JP 2000-190155 A

  However, some workpieces are difficult to cut depending on the material and structure thereof, and some blades are subjected to higher processing loads during cutting. In such a case, there is a problem that meandering occurs at a predetermined amount of leading edge, resulting in poor cutting.

  For cutting such workpieces, the use of a hub blade with a reduced cutting edge allows processing without cutting defects, but the life of the hub blade is shortened and the frequency of blade replacement is increased. Therefore, the work becomes complicated.

  This invention is made | formed in view of such a point, The place made into the objective is providing the cutting device which has a hub blade which can perform a blade tip according to abrasion of a grindstone part. .

According to the present invention, there is provided a cutting apparatus comprising: a chuck table that holds a workpiece; and a cutting means that is rotatably mounted with a hub blade that cuts the workpiece held on the chuck table. The hub blade is composed of a hub base integrally formed with a circular hub, and a grindstone formed on the outer peripheral portion of the side opposite to the circular hub of the hub base. A projecting portion projecting from the outer periphery of the base , and a contact portion having a predetermined width in the inner peripheral direction from the outer periphery of the hub base and closely contacting the hub base , wherein the hub base is mainly made of aluminum. together it is formed as the grinding stone portion is formed of abrasive grains in electroforming solidified with nickel plating or nickel alloy plating, comprising an etching liquid supplying means for supplying the etchant to the outer periphery of the hub base, the etching Cutting apparatus, characterized in that the aqueous solution containing the sodium hydroxide is provided.

  According to the present invention, since the grindstone portion can be protruded from the hub base at any time according to the consumption of the grindstone portion, the amount of the blade tip of the hub blade can be minimized. As a result, the rigidity of the hub blade can be further increased, and the bending and meandering of the blade can be prevented and cutting with a high load can be performed.

  Even if the wheel part of the hub blade is worn out and the protruding part disappears, the hub base is etched by supplying the etchant to the hub base of the rotating hub blade, and a new wheel part is then added to the hub base. It is possible to protrude from. Accordingly, it is possible to extend the life of the blade as compared with a conventional hub blade having a preset blade tip amount.

  Furthermore, since the amount of hub blades used can be reduced, costs can be reduced, and there is no need to make pre-processing adjustments when replacing the hub blades with new ones, improving the cutting work efficiency. It becomes possible.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an appearance of a cutting apparatus 2 according to an embodiment of the present invention, which can divide a semiconductor wafer into individual chips (devices).

  On the front side of the cutting device 2, there is provided operating means 4 for an operator to input instructions to the device such as machining conditions. In the upper part of the apparatus, there is provided a display means 6 such as a CRT for displaying a guidance screen for an operator and an image taken by an imaging means described later.

  As shown in FIG. 2, on the surface of the wafer W to be diced, the first street S1 and the second street S2 are formed orthogonally, and the first street S1 and the second street S2 A plurality of devices D are partitioned and formed on the wafer W.

  The wafer W is attached to a dicing tape T that is an adhesive tape, and the outer peripheral edge of the dicing tape T is attached to an annular frame F. As a result, the wafer W is supported by the frame F via the dicing tape T, and a plurality of wafers (for example, 25 sheets) are accommodated in the wafer cassette 8 shown in FIG. The wafer cassette 8 is placed on a cassette elevator 9 that can move up and down.

  Behind the wafer cassette 8, a loading / unloading means 10 for unloading the wafer W before cutting from the wafer cassette 8 and loading the wafer after cutting into the wafer cassette 8 is disposed. Between the wafer cassette 8 and the loading / unloading means 10, a temporary placement area 12, which is an area on which a wafer to be carried in / out, is temporarily placed, is provided. Positioning means 14 for positioning at a certain position is provided.

  In the vicinity of the temporary placement area 12, transport means 16 having a turning arm that sucks and transports the frame F integrated with the wafer W is disposed, and the wafer W carried to the temporary placement area 12 is It is attracted by the transport means 16 and transported onto the chuck table 18 and is sucked by the chuck table 18, and is held on the chuck table 18 by fixing the frame F by a plurality of fixing means 19.

  The chuck table 18 is configured to be rotatable and reciprocally movable in the X-axis direction. Above the movement path of the chuck table 18 in the X-axis direction, an alignment unit 20 that detects a street to be cut of the wafer W is provided. It is arranged.

  The alignment unit 20 includes an imaging unit 22 that images the surface of the wafer W, and can detect a street to be cut by a process such as pattern matching based on an image acquired by imaging. The image acquired by the imaging unit 22 is displayed on the display unit 6.

  On the left side of the alignment means 20, a cutting means 24 for cutting the wafer W held on the chuck table 18 is disposed. The cutting means 24 is configured integrally with the alignment means 20, and both move together in the Y-axis direction and the Z-axis direction.

  The cutting means 24 is configured by mounting a cutting blade (hub blade) 28 on the tip of a rotatable spindle 26 and is movable in the Y-axis direction and the Z-axis direction. The cutting blade 28 is located on the extended line of the imaging means 22 in the X-axis direction.

  In the cutting apparatus 2 configured as described above, the wafer W accommodated in the wafer cassette 8 is sandwiched by the frame F by the loading / unloading means 10, and the loading / unloading means 10 moves to the rear of the apparatus (Y-axis direction). When the nipping is released in the placing area 12, the placing area 12 is placed in the temporary placing area 12. Then, the wafer W is positioned at a certain position by the positioning means 14 moving in a direction approaching each other.

  Next, the frame F is adsorbed by the transport unit 16, and the wafer W integrated with the frame F is transported to the chuck table 18 and held by the chuck table 18 as the transport unit 16 rotates. Then, the chuck table 18 moves in the X-axis direction, and the wafer W is positioned directly below the alignment means 20.

  The image used for pattern matching at the time of alignment in which the alignment unit 20 detects a street to be cut needs to be acquired in advance before cutting. Therefore, when the wafer W is positioned directly below the alignment unit 20, the imaging unit 22 captures the surface of the wafer W and causes the display unit 6 to display the captured image.

  The operator of the cutting apparatus 2 operates the operation unit 4 to move the image pickup unit 22 slowly and also move the chuck table 18 as necessary to search for a pattern that is a pattern matching target.

  When the operator determines a key pattern, an image including the key pattern is stored in a memory provided in the controller of the cutting apparatus 2. Further, the distance between the key pattern and the center line of the streets S1 and S2 is obtained by a coordinate value or the like, and the value is also stored in the memory.

  Further, by moving the image pickup means 22, an interval between the adjacent streets (street pitch) is obtained by a coordinate value or the like, and the street pitch value is also stored in the memory of the controller.

  At the time of cutting along the street of the wafer W, the alignment unit 20 performs pattern matching between the stored key pattern image and the image actually acquired by the imaging unit 22.

  When the pattern matches, the cutting means 24 is moved in the Y-axis direction by the distance between the key pattern and the street center line, thereby aligning the street to be cut with the cutting blade 28.

  When the street to be cut and the cutting blade 28 are aligned, the chuck table 18 is moved in the X-axis direction, and the cutting means 24 is lowered while rotating the cutting blade 28 at a high speed. The street was cut.

  By performing cutting while feeding the cutting means 24 in the Y-axis direction by the street pitch stored in the memory, all the streets S1 in the same direction are cut. Furthermore, when the chuck table 18 is rotated by 90 ° and then the same cutting as described above is performed, the streets S2 are all cut and divided into individual devices D.

  The wafer W that has been cut is moved in the X-axis direction by the chuck table 18 and is then gripped by the transfer means 25 that can move in the Y-axis direction and transferred to the cleaning device 27. The cleaning device 27 cleans the wafer by rotating the wafer W at a low speed (for example, 300 rpm) while jetting water from the cleaning nozzle.

  After cleaning, while rotating the wafer W at a high speed (for example, 3000 rpm), air is blown out from the air nozzle to dry the wafer W, and then the wafer W is sucked by the conveying means 16 and returned to the temporary storage area 12, and further carried in and out. By means 10, the wafer W is returned to the original storage location of the wafer cassette 8.

  By the way, as the cutting blade 28 used in the cutting apparatus 2, a type called a hub blade as shown in the sectional view of FIG. 3 is often used. The hub blade 28 is configured by electrodepositing a grindstone portion (cutting blade) 34 in which diamond abrasive grains are dispersed in a nickel base material or a nickel alloy base material on the outer periphery of a hub base 30 having a circular hub 32. Yes. The hub base 30 is made of a material mainly made of aluminum such as an aluminum alloy.

  The hub blade 28 further includes an annular tapered portion 36 that connects the outer periphery of the hub base 30 and the base of the circular hub 32, a mounting hole 38, and shallow countersunk portions 40 and 42 formed on both sides of the hub base 30. have.

  The countersunk portions 40 and 42 are provided to reduce the contact area and increase the mounting accuracy with respect to the spindle 26 when the hub blade 28 is mounted on a mount flange (not shown) fixed to the spindle 26.

  As apparent from FIG. 3, the shape of the hub blade 28 is formed asymmetrically between the circular hub 32 side and the grindstone 34 side. The grindstone portion 34 includes a close contact portion 34a electroformed on the side surface of the hub base 30 and a protruding portion 34b protruding from the outer periphery of the hub base 30. The workpiece 34 is cut by the protruding portion 34b.

  By the way, when the grindstone portion 34 is consumed with the cutting process and the protruding portion 34b from the outer periphery of the hub base 30 is not consumed, it has been conventionally necessary to replace it with a new hub blade. The present invention is intended to provide a cutting device capable of extending the life of the hub blade 28 by forming a new protruding portion on the hub blade 28 in which the protruding portion 34b is consumed as described above. The embodiment of the present invention will be described in detail with reference to FIGS.

  Referring to FIG. 4, there is shown a schematic configuration diagram of an etching solution supply structure according to the first embodiment of the present invention for supplying an etching solution to the outer periphery of the hub base. Reference numeral 44 denotes a spindle unit of the cutting means 24. In a spindle housing 46 of the spindle unit 44, a spindle 26 that is rotationally driven by a servo motor (not shown) is rotatably accommodated. A flange mount (not shown) is fixed to the tip of the spindle 26, and a hub blade 28 is attached to the flange mount.

  A blade cover 48 covers the hub blade 28, and a cutting water supply nozzle (not shown) extending along the side surface of the hub blade 28 is attached to the blade cover 48.

  The pipe 60 attached to the blade cover 48 is connected to a cutting water supply source 66 via an electromagnetic switching valve 64. When the electromagnetic switching valve 64 is opened, cutting water is not shown via the pipe 60. Supplied to the supply nozzle.

  A detachable cover 58 is attached to the blade cover 48 with screws 52. The detachable cover 50 has a cutting water supply nozzle 58 that extends along the side surface of the hub blade 28 when attached to the blade cover 48.

  The pipe 62 attached to the detachable cover 50 is selectively connected to the cutting water supply source 66 via the electromagnetic on-off valve 68 and further connected selectively to the etching solution supply source 72 via the electromagnetic on-off valve 70. . The pipe 62 is connected to the cutting water supply nozzle 58. In the present embodiment, the cutting water supply nozzle 58 is also used as an etching liquid supply nozzle.

  A blade detection block 54 is attached to the blade cover 48 by screws 56. A blade sensor (not shown) composed of a light emitting part and a light receiving part is attached to the blade detection block 54, and the state of the grindstone part (cutting edge) 34 of the hub blade 28 is detected by this blade sensor.

  When the chip of the grindstone 34 is detected by the blade sensor, the hub blade 28 is replaced with a new hub blade. 63 is an adjusting screw for adjusting the position of the blade sensor.

  On the other hand, when the wear of the protrusion 34b of the grindstone 34 is detected by the blade sensor, in this embodiment, it is not necessary to replace the hub blade 28 with a new hub blade, and the annular tapered portion 36 of the hub base 30 is used. A protrusion 34b is newly formed by etching the outer peripheral portion of the protrusion.

  In order to etch and remove the outer peripheral portion of the annular taper portion 36 of the hub base 30 by a predetermined amount, the cutting water supply nozzle 58 of the present embodiment is configured to be movable in the Z direction (vertical direction). The cutting water supply nozzle 58 is positioned at a position facing the outer peripheral portion of the annular tapered portion 36 of the hub blade 28.

  Then, by closing the electromagnetic on-off valve 68 and opening the electromagnetic on-off valve 70, the etching liquid is ejected from the etching liquid supply nozzle 58 toward the annular tapered portion 36 of the hub base 30. As a result, as shown in FIG. 6, the circular hub 32 and the annular taper portion 36 are etched to the position indicated by the alternate long and short dash line 36 'to form a new protruding portion 34b'.

  The etchant is preferably an aqueous solution containing sodium hydroxide. By using such an etchant, the hub base 30 formed with aluminum as a main material can be selectively etched. In this case, since the grindstone portion 34 is formed by electroforming in which diamond abrasive grains are hardened by nickel plating or nickel alloy plating, it is not etched by the etching solution.

  Referring to FIG. 5, there is shown a schematic configuration diagram of an etching solution supply structure according to a second embodiment of the present invention. In the present embodiment, an etching solution supply nozzle 74 is newly provided in the blade cover 48, and this etching solution supply nozzle 74 is connected to the etching solution supply source 72 via the pipe 76 and the electromagnetic on-off valve 70.

  When the taper portion 36 of the hub base 30 is etched, the electromagnetic on-off valve 70 is opened to connect the etchant supply nozzle 74 to the etchant supply source 72, and the etchant supply nozzle 74 connects to the annular taper portion 36 of the hub base 30. Etching solution is jetted out.

  Accordingly, as in the first embodiment shown in FIG. 4, the circular hub 32 and the annular tapered portion 36 are etched by a predetermined amount as shown in FIG. 6, and a protruding portion 34b ′ can be newly formed. In the first and second embodiments, the etching is performed by rotating the hub blade 28 at a low speed such as 3000 to 4000 rotations during the etching.

  In the first and second embodiments, it is preferable to provide a mechanism for detecting that a predetermined amount of etching has been completed. For example, when a laser range finder is provided so as to face the tip of the annular taper portion 36 and the annular taper portion 36 is etched by etching and the protruding portion 34 b ′ is exposed, the measured distance is a predetermined distance to the surface of the grindstone portion 34. Therefore, the etching may be stopped at this point.

  Referring to FIG. 7, an external perspective view of a cutting device according to a third embodiment of the present invention is shown. In the present embodiment, a small etching solution tank 80 is provided at an appropriate position, and the hub blade 28 is immersed in the etching solution tank 80 while rotating, thereby achieving desired etching.

  In FIG. 7, the etching solution tank 80 is provided in the vicinity of the chuck table 18 so that the etching solution tank 80 can be easily seen. However, in practice, it is preferable to provide the etching solution tank in a non-movable part such as under the spindle 26. .

It is an external appearance perspective view of a cutting device. It is a perspective view which shows the wafer integrated with the flame | frame. It is a longitudinal cross-sectional view of a hub blade. It is a schematic block diagram which shows the etching liquid supply structure of 1st Embodiment of this invention. It is a schematic block diagram which shows the etching liquid supply structure of 2nd Embodiment of this invention. It is explanatory drawing for demonstrating an etching state. It is an external appearance perspective view of the cutting device which has the etching liquid supply structure of 3rd Embodiment of this invention.

Explanation of symbols

2 Cutting device 18 Chuck table 24 Cutting means 26 Spindle 28 Hub blade (cutting blade)
30 Hub base 32 Circular hub 34 Grinding wheel (cutting blade)
34a Contact part 34b Protrusion part 36 Annular taper part 58 Cutting water supply nozzle (etching liquid supply nozzle)
72 Etching solution supply source 74 Etching solution supply nozzle 80 Etching solution tank

Claims (1)

A cutting apparatus comprising: a chuck table for holding a workpiece; and a cutting means on which a hub blade for cutting the workpiece held on the chuck table is rotatably mounted,
The hub blade is composed of a hub base integrally formed with a circular hub, and a grindstone formed on the outer peripheral portion of the hub base on the side opposite to the circular hub,
The grindstone portion has a protruding portion protruding from the outer periphery of the hub base, and a close contact portion closely contacting the hub base with a predetermined width from the outer periphery of the hub base to the inner peripheral direction,
The hub base is formed of aluminum as a main material, and the grindstone is formed by electroforming in which abrasive grains are hardened by nickel plating or nickel alloy plating.
Etching solution supplying means for supplying an etching solution to the outer periphery of the hub base ,
The cutting apparatus, wherein the etching solution is an aqueous solution containing sodium hydroxide .

Images