JP2023033302A - Processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing device that is configured so that a position of processing means in an axial direction of a spindle can be detected with good accuracy.

SOLUTION: The processing device is provided with: a spindle 48 supported on a Y table 40, whose shaft center is arranged along a moving direction of the Y table 40; a spindle motor 46 whose blade 22 is mounted on the spindle 48; a linear scale 52 provided along the moving direction; a detector 54 that moves together with the Y table 40 to read out a value of the linear scale 52; and a thermal expansion member 56 whose one end in the moving direction is fixed to the Y table 40 and whose other end in the moving direction is fixed with the detector 54, which can thermally expand in the moving direction. The thermal expansion member 56 can thermally expand in the moving direction by amounts of positional shift in the moving direction of the blade 22 caused by the thermal expansion of the spindle 48.

SELECTED DRAWING: Figure 4

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a processing apparatus, and more particularly to a processing apparatus such as a dicing apparatus that cuts a workpiece such as a semiconductor wafer while feeding a blade in the index direction.

A dicing machine performs cutting such as cutting or grooving on a workpiece such as a semiconductor wafer on which a semiconductor device or an electronic component is formed, using a blade that rotates at high speed. In the dicing machine, index feed in the Y-axis direction and cutting feed in the Z-axis direction of a spindle on which a blade is attached, and grinding feed in the X-axis direction and rotation in the θ direction of a work table on which a work is placed are performed. Cut the workpiece into a die shape.

In such a dicing machine, the current position of the blade is detected as XYZ three-dimensional coordinates in order to perform highly accurate processing. As an example of detecting the Y-coordinate among the coordinates, Patent Document 1 discloses a dicing apparatus that includes a Y-axis linear scale and a detector (reading head) that reads the value of the Y-axis linear scale.

Further, Patent Document 2 discloses a dicing apparatus having a cooling function of cooling a spindle with cooling liquid. According to this dicing machine, a cooling system for supplying the aforementioned cooling liquid is provided inside a casing that rotatably holds a spindle via an air bearing. By cooling the spindle with the cooling liquid, it is possible to suppress the temperature rise of the spindle during processing, thereby suppressing the amount of thermal expansion in the axial direction (Y-axis direction) of the spindle. Y-coordinate errors can be suppressed.

Japanese Patent Application Laid-Open No. 2007-088028 Japanese Patent Application Laid-Open No. 2002-141307

However, in the conventional dicing apparatus, the temperature of the cooling liquid for cooling the spindle rises with the passage of processing time of the workpiece, so that the thermal expansion of the spindle in the Y-axis direction cannot be effectively suppressed. As a result, since the spindle is displaced in the Y-axis direction, there is a problem that an error occurs in the Y-coordinate of the blade, which is the processing means.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a processing apparatus capable of precisely controlling the position of a processing means in the axial direction of a spindle.

In order to achieve the object of the present invention, the processing apparatus of the present invention comprises a base member, a moving member movably provided on the base member, and a spindle motor supported by the moving member, wherein the moving member moves A spindle motor having a spindle in a direction, a processing means attached to the spindle, a linear scale provided along the moving direction, a detector that moves with the moving member and reads the value of the linear scale, and one end that moves The thermal expansion member is fixed to the member, the detector is fixed to the other end, and the thermal expansion member is thermally expandable in the moving direction with one end serving as a first reference position, and the same cooling liquid cools the spindle and the thermal expansion member. and a cooling system.

According to one aspect of the present invention, the thermal expansion member is preferably an elongated member whose longitudinal direction is the moving direction.

According to one aspect of the present invention, the length of the thermal expansion member in the movement direction is preferably selected based on the amount of thermal expansion of the spindle.

According to one aspect of the present invention, the material of the thermal expansion member is preferably selected based on the amount of thermal expansion of the spindle.

According to one aspect of the present invention, the thermal expansion member has an amount of thermal expansion per unit temperature from the first reference position to the fixed position of the detector, which is the unit from the second reference position on the spindle to the mounting position of the processing means. It is preferably configured to be equal or approximate to the amount of thermal expansion per temperature.

According to one aspect of the present invention, the processing means is preferably a blade for grinding the work.

According to the present invention, it is possible to accurately control the position of the processing means in the axial direction of the spindle.

1 is a perspective view showing the appearance of a dicing apparatus according to an embodiment; FIG. FIG. 2 is a perspective view showing the configuration of the processing section of the dicing apparatus of FIG. 1; Explanatory drawing showing the structure of the position detection device provided in the processing part of FIG. Explanatory diagram of the spindle and the thermal expansion member thermally expanding from the state shown in FIG. Explanatory diagram of thermal expansion of the spindle of the conventional dicing machine Graph showing changes in Y-coordinate blade error amount, etc. in a comparative example Graph showing changes in Y-coordinate blade error amount, etc. in the embodiment

Preferred embodiments of the processing apparatus according to the present invention will be described below with reference to the accompanying drawings. In the embodiment, a dicing apparatus, which is an example of a processing apparatus, will be described as an example.

FIG. 1 is a perspective view showing the appearance of a dicing apparatus 10 according to an embodiment.

As shown in FIG. 1, the dicing apparatus 10 includes a processing section 12 for processing a work W such as a semiconductor wafer, a cleaning section 14 for spin cleaning the processed work W, and a cassette containing a large number of works W. A load port 16 to be placed thereon and a transfer device 18 for transferring the work W are provided.

In this specification, a three-dimensional orthogonal coordinate system in three axial directions (X-axis direction, Y-axis direction, Z-axis direction) is used for description. The X-axis direction shown in FIG. 1 is the horizontal direction and indicates the cutting feed direction of an X table 20 (see FIG. 2), which will be described later. The Y-axis direction is a horizontal direction orthogonal to the X-axis direction, and indicates an index feeding direction of the blade 22, which will be described later. Furthermore, the Z-axis direction is a vertical direction orthogonal to the X-axis direction and the Y-axis direction, and indicates the cutting feed direction of the blade 22 .

FIG. 2 is a perspective view showing the configuration of the processing section 12. As shown in FIG.

As shown in FIG. 2, the processing unit 12 has an X table 20 guided by a pair of X guide rails 26, 26 of an X base 24 and moved in the X axis direction by a linear motor 28. . A work table 32 is provided on the X table 20 via a rotary table 30 that rotates in the .theta. direction.

As an example, the work table 32 is configured in a disk shape, and has a horizontally flat suction surface 34 on its upper surface, to which the workpiece W (see FIG. 1) is vacuum-sucked and fixed. .

A Y base 36 is erected above the X base 24 so as to straddle the X base 24 . A pair of Y tables 40 , 40 guided by a pair of Y guide rails 38 , 38 and movable in the Y-axis direction are provided on the front of the Y base 36 . The Y tables 40 , 40 are moved in the Y-axis direction by a Y-axis drive mechanism (not shown) provided on the Y base 36 . Note that the Y base 36 is an example of a base member that is a component of the present invention. Also, the Y table 40 is an example of a moving member that is a component of the present invention.

The Y tables 40, 40 are provided with Z tables 44, 44 that are driven in the Z-axis direction by a Z-axis drive mechanism (not shown). High-frequency motor built-in spindle motors 46, 46 are fixed to the Z tables 44, 44 so as to face each other in the Y-axis direction. are fixed in a state of facing each other. These spindle motors 46 , 46 are supported by Y tables 40 , 40 via Z tables 44 , 44 , and spindles 48 , 48 have Y axes whose axes are in the moving direction of Y tables 40 , 40 . arranged along the direction.

As an example, the blade 22 is an electrodeposited blade in which diamond abrasive grains or CBN (cubic boron nitride) abrasive grains are electrodeposited with nickel. In addition to the electrodeposition blade, a metal-resin bond blade bonded with a resin mixed with metal powder can also be used. This blade 22 is rotated at a high speed of, for example, 6000 rpm to 80000 rpm by a spindle 48 .

According to the processing unit 12 configured as described above, the work table 32 is fed by the X table 20 in the X-axis direction and rotated in the θ direction by the rotary table 30 . The blades 22, 22 are index-fed in the Y-axis direction by the Y-axis drive mechanism and are cut-fed in the Z-axis direction by the Z-axis drive mechanism. The workpiece W is cut in a grid pattern by the operation of the processing unit 12 as described above.

The position detection device 50 for detecting the current position (Y coordinate) of the blade 22 in the Y-axis direction will be described below with reference to FIG. FIG. 3 is an explanatory diagram schematically showing the structure of the position detection device 50 provided in the processing section 12. As shown in FIG.

As shown in FIG. 3 , the position detection device 50 includes a linear scale 52 and a detector (also called read head) 54 . The linear scale 52 is arranged in the Y-axis direction along the Y guide rails 38, 38 on the front surface of the Y base 36, as shown in FIG. That is, the linear scale 52 is provided along the Y-axis direction, which is the moving direction of the spindle motor 46 .

As shown in FIG. 3, the detector 54 is provided on the back side of the Y table 40 so as to face the linear scale 52 . Further, the detector 54 is provided on the Y table 40 via a thermal expansion member 56 which will be described later. The detector 54 moves along the linear scale 52 as the Y-table 40 moves in the Y-axis direction. The detector 54 reads the value of the linear scale 52 while moving in the Y-axis direction, and transmits a pulse signal of, for example, one pulse per 1 μm to the controller (not shown) of the dicing apparatus 10 . The control device then detects the current position of the blade 22 as the Y coordinate by counting the input pulse signals. Thereby, the current position of the blade 22 in the Y-axis direction can be detected. Since the position detection device including the linear scale and the detector has a known configuration, detailed description thereof will be omitted.

On the other hand, as shown in FIG. 3, a cooling system 60 is connected to the spindle motor 46 . The cooling system 60 has a conduit through which the coolant flows along the arrow, as simply indicated by the thick line in FIG. The cooling system 60 also has a pump 62 which supplies cooling liquid to the spindle motor 46 through a conduit. As the cooling system 60, the configuration for cooling the inside of the spindle motor 46 is not particularly limited. .

Next, the thermal expansion member 56 will be explained. This thermal expansion member 56 is an example of a thermal expansion member that is a component of the present invention.

The thermal expansion member 56 is an elongated member whose longitudinal direction A is the Y-axis direction, which is the moving direction of the spindle motor 46 . The thermal expansion member 56 has the detector 54 fixed to the right end 56A in FIG. That is, the thermal expansion member 56 is configured to be thermally expandable in the Y-axis direction with the left end 56B as the first reference position.

Here, the thermal expansion member 56 in the embodiment is configured as follows in order to cancel the influence of the thermal expansion of the spindle 48 (positional deviation of the blade 22 in the Y-axis direction).

That is, the thermal expansion member 56 has an amount of thermal expansion per unit temperature from the left end 56B, which is the first reference position, to the right end 56A, which is the fixed position of the detector 54. It is configured to satisfy a condition equivalent to or similar to the amount of thermal expansion per unit temperature (hereinafter referred to as "thermal expansion member condition") up to the right end 48B, which is the position. Specifically, the length (the length from the left end 56B to the right end 56A) L of the thermal expansion member 56 in the Y-axis direction and the material thereof are selected based on the amount of thermal expansion of the spindle 48 . The second reference position of the spindle 48 is a reference position for specifying the amount of thermal expansion when the spindle 48 thermally expands. In the embodiment, as an example, the left end 48A of the spindle 48 is the second reference position.

For example, the characteristic of the spindle 48 (amount of thermal expansion in the Y-axis direction per 1° C. of cooling liquid) is 10 μm/° C., and the material of the thermal expansion member 56 is SUS303 ( linear expansion coefficient: 17.3×10 −6 /° C.), the length L of the thermal expansion member 56 in the Y-axis direction is set so that the spindle characteristic (10 μm/° C.) is equal to the linear expansion coefficient of SUS303 (17.0 μm/° C.). 3×10−6/° C.). That is, the length L of the thermal expansion member 56 in the Y-axis direction is 0.58 m. When SUS303 is selected as the material for the thermal expansion member 56 in this way, the thermal expansion member condition can be satisfied by adopting a thermal expansion member 56 with a length L of 0.58 m in the Y-axis direction. can. If the length of the thermal expansion member 56 is restricted, it is possible to change the material of the thermal expansion member 56 so as to satisfy the thermal expansion member condition. In addition, the “approximation” in the thermal expansion member condition means the ratio of the difference (absolute value) between the thermal expansion amount of the spindle 48 and the thermal expansion amount of the thermal expansion member 56 to the thermal expansion amount of the spindle 48 (hereinafter referred to as “thermal ) is within 30% (preferably within 20%). In addition, "equivalent" in the thermal expansion member conditions means that the thermal expansion amount ratio is within 10%.

In addition to the configuration of the thermal expansion member 56 described above, the embodiment further includes a cooling system 60 that cools the spindle 48 and the thermal expansion member 56 with the same coolant. That is, the thermal expansion member 56 is connected to the spindle motor 46 via a cooling system 60, as shown in FIG.

FIG. 4 is an explanatory view showing a state in which both the spindle 48 and the thermal expansion member 56 are thermally expanded in the Y-axis direction from the state shown in FIG. 3 by chain double-dashed lines. As shown in FIG. 4, in the embodiment, the cooling system 60 circulates the same coolant through the spindle 48 and the thermal expansion member 56 so that the temperature of the thermal expansion member 56 is substantially the same as the temperature of the spindle 48. kept at a temperature of In the embodiment, the thermal expansion member 56 is configured to satisfy the thermal expansion member conditions as described above. Therefore, the thermal expansion amounts of both the spindle 48 and the thermal expansion member 56 are substantially the same. As a result, even if the blade 22 is displaced in the Y-axis direction due to the thermal expansion of the spindle 48, the thermal expansion member 56 thermally expands by an amount corresponding to the amount of displacement. The position of the detector 54 fixed to the tip (right end 56A) of the thermal expansion member 56 is also shifted in the Y-axis direction. That is, the detector 54 is shifted in the Y-axis direction by an amount corresponding to the displacement of the detector 54 caused by the thermal expansion of the spindle 48 .

Therefore, in the embodiment, the detector 54 shifted in the Y-axis direction reads the value of the linear scale 52, and the position of the blade 22 is controlled based on the reading result. As a result, the position of the blade 22 is shifted in the Y-axis direction by an amount corresponding to the amount of shift of the detector 54 in the Y-axis direction (that is, the amount of positional deviation of the blade 22 in the Y-axis direction due to the thermal expansion of the spindle 48). will be offset to the opposite side. As described above, in the embodiment, the thermal expansion of the spindle 48 is actively used to shift the position of the detector 54 by the amount corresponding to the amount of displacement of the blade 22 in the Y-axis direction due to the thermal expansion of the spindle 48. As a result, the influence of thermal expansion of the spindle 48 can be effectively canceled, and the position of the blade 22 can be controlled with high accuracy.

Here, a comparative example for comparison with the embodiment will be described with reference to FIG. FIG. 5 is an explanatory diagram schematically showing the structure of the processing portion 100 as a comparative example. In describing the processing unit 100, members that are the same as or similar to the configuration of the processing unit 12 shown in FIGS.

As shown in FIG. 5, the detector 54 in the comparative example is fixed to the Y table 40 via a rectangular parallelepiped block 102 that is shorter than the thermal expansion member 56 of the embodiment. The block 102 is made of a material having a smaller thermal expansion coefficient than the material forming the thermal expansion member 56 of the embodiment. Also, the cooling system 104 in the comparative example does not supply cooling liquid to the block 102 , and supplies cooling liquid only to the spindle 48 .

According to the comparative example configured in this manner, when the spindle 48 thermally expands, the blade 22 is displaced in the Y-axis direction along with the thermal expansion. At this time, the block 102 is not affected by the thermal expansion of the spindle 48, so unlike the embodiment, the position of the detector 54 is not shifted in the Y-axis direction. Therefore, when the detector 54 reads the value of the linear scale 52 and attempts to control the position of the blade 22 based on the reading result, the thermal expansion of the spindle 48 directly affects the position of the blade 22 as described above. Misalignment occurs. Therefore, it is difficult to accurately control the position of the blade 22 in the comparative example.

Next, experimental results of the processing portion 100 of the comparative example shown in FIG. 5 and the processing portion 12 of the embodiment shown in FIG. 3 will be described with reference to the graphs shown in FIGS. 6 and 7. FIG. The graph of FIG. 6 is the experimental result of the comparative example, and the graph of FIG. 7 is the experimental result of the processing unit 12 of the embodiment.

In the graph shown in FIG. 6, the horizontal axis indicates the elapsed time (minutes) of the machining time, the left vertical axis indicates the temperature (° C.), and the right vertical axis indicates the blade error amount (μm). The blade error amount is the error amount between the actual Y coordinate of the blade 22 and the Y coordinate of the blade 22 detected by the detector 54 or the like. In the graph of FIG. 6, line I indicates the temperature change of the cooling liquid in the comparative example, line II indicates the temperature change of the block 102, line III indicates the temperature change of the spindle 48, and blade error amount is shown by line IV.

As shown by line II in FIG. 6, in the comparative example, as the machining time elapses, the temperature of the spindle 48 gradually rises (line III), and the temperature of the coolant gradually rises accordingly. (line I). On the other hand, since the cooling liquid is not supplied to the block 102, the temperature of the block 102 is substantially constant without being affected by the temperature rise of the spindle 48 and the cooling liquid (line II). Therefore, in the comparative example, the blade 22 is directly affected by the thermal expansion of the spindle 48, and the blade 22 is displaced in the Y-axis direction due to the thermal expansion of the spindle 48. It increases with time (line IV). Therefore, in the comparative example, it is difficult to accurately control the position of the blade 22 in the axial direction of the spindle 48 .

On the other hand, in the graph of FIG. 7, the temperature change of the coolant in the embodiment is indicated by line V, the temperature change of the thermal expansion member 56 is indicated by line VI, the temperature change of the spindle 48 is indicated by line VII, and the blade The change in error amount is shown by line VIII. The horizontal axis, the left vertical axis, and the right vertical axis of the graph of FIG. 7 are the same as those of the graph of FIG.

In the embodiment, as shown in FIG. 7, when the temperature of the spindle 48 gradually rises (line VII) as the machining time elapses, the temperature of the cooling liquid also gradually rises (line V) so as to follow it. Furthermore, the temperature of the thermal expansion member 56 also gradually rises (line VI). That is, during processing, the temperature of the thermal expansion member 56 is kept substantially the same as the temperature of the spindle 48 . Therefore, as described above, the detector 54 is shifted by an amount corresponding to the amount of positional deviation of the blade 22 in the Y-axis direction due to the thermal expansion of the spindle 48, and is therefore affected by the thermal expansion of the spindle 48. Therefore, the blade error amount can be greatly reduced compared to the comparative example described above. Therefore, in the embodiment, the influence of thermal expansion of the spindle 48 can be effectively canceled, so the position of the blade 22 in the axial direction of the spindle 48 can be controlled with high accuracy.

As described above, according to the dicing apparatus 10 of the embodiment, the thermal expansion member 56 to which the detector 54 is fixed is configured to satisfy the thermal expansion member conditions, and the spindle 48 and the thermal expansion member 56 are at the same temperature. Since the influence of the thermal expansion of the spindle 48 can be effectively canceled by providing the configuration such that .

Moreover, by adopting the above configuration, it is possible to eliminate the need for a temperature control chiller for controlling the temperature of the coolant to be constant. In this case, it is possible to solve the problems of securing installation space for the temperature control chiller and increasing the running cost of the temperature control chiller. Note that the cooling system 60 may include a temperature control chiller.

Further, in the embodiment, the thermal expansion member 56 is preferably formed of an elongated member, but there is no particular limitation as long as it is a member having a thermal expansion amount that is approximately the same as the thermal expansion amount of the spindle 48 . . Moreover, the cross section of the thermal expansion member 56 perpendicular to the longitudinal direction (Y-axis direction) A is not limited to a rectangular shape, and may be circular or polygonal. However, by forming the thermal expansion member 56 from an elongated member, there is an advantage that the amount of thermal expansion of the thermal expansion member 56 can be easily controlled in response to temperature changes.

In addition, as a form in which the cooling system 60 is provided in the thermal expansion member 56, a form in which the cooling system 60 is provided through the inside of the thermal expansion member 56 may be used. The form which adheres the cooling system 60 may be sufficient. 3 and 4, the cooling system 60 is not limited to the configuration in which the spindle 48 and the thermal expansion member 56 are connected in series, but may be configured in parallel connection.

Furthermore, in the embodiment, the dicing apparatus 10 including the linear scale 52 and the detector 54 for detecting the Y coordinate of the blade 22 was illustrated, but the present invention can be applied to processing apparatuses other than the dicing apparatus 10. can. For example, the present invention can be applied to a processing apparatus having a processing means such as a blade or a drill, provided that it has a linear scale 52 and a detector 54 as a detection device for detecting the coordinates of the processing means.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above examples, and of course various improvements and modifications may be made without departing from the gist of the present invention. .

DESCRIPTION OF SYMBOLS 10... Dicing apparatus, 12... Processing part, 14... Cleaning part, 16... Load port, 18... Conveying apparatus, 20... X table, 22... Blade, 24... X base, 26... X guide rail, 28... Linear motor, DESCRIPTION OF SYMBOLS 30... Rotary table, 32... Work table, 34... Attraction surface, 36... Y base, 38... Y guide rail, 40... Y table, 44... Z table, 46... Spindle motor, 48... Spindle, 50... Position detector , 52... Linear scale, 54... Detector, 56... Thermal expansion member, 60... Cooling system, 62... Pump, 64... Fixed member

Claims (4)

a moving member movably provided;
a spindle motor supported by the moving member, the spindle motor having a spindle whose axis is arranged along the moving direction of the moving member, and a machining means attached to the spindle;
a linear scale provided along the movement direction;
a detector that moves with the moving member and reads the value of the linear scale;
a thermal expansion member having one end in the moving direction fixed to the moving member, the detector being fixed to the other end opposite to the one end in the moving direction, and thermally expandable in the moving direction; ,
with
The processing apparatus according to claim 1, wherein the thermal expansion member is thermally expandable in the movement direction by an amount corresponding to a positional deviation amount of the processing means in the movement direction due to thermal expansion of the spindle. 2. Control means for controlling the position of said processing means in said moving direction so as to cancel the amount of positional deviation of said processing means due to thermal expansion of said spindle based on the reading result of said detector. The processing device according to . a moving member movably provided;
a spindle motor supported by the moving member, the spindle motor having a spindle whose axis is arranged along the moving direction of the moving member, and a machining means attached to the spindle;
a linear scale provided along the moving direction;
a detector that moves with the moving member and reads the value of the linear scale;
a thermal expansion member having one end in the moving direction fixed to the moving member, the detector being fixed to the other end opposite to the one end in the moving direction, and thermally expandable in the moving direction; ,
control means for controlling the position of the processing means in the moving direction based on the reading result of the detector so as to cancel the amount of positional deviation of the processing means due to thermal expansion of the spindle;
A processing device. 4. The processing apparatus according to any one of claims 1 to 3, further comprising a temperature adjustment device that adjusts the spindle and the thermal expansion member so that they have the same temperature.

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