JP7429354B2 - processing equipment - Google Patents

Description

The present invention relates to a processing device, and more particularly to a processing device such as a dicing device that cuts a workpiece such as a semiconductor wafer while sending a blade in an indexing direction.

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

In such a dicing apparatus, the current position of the blade is detected as three-dimensional XYZ 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.

Moreover, Patent Document 2 discloses a dicing apparatus having a cooling function of cooling a spindle with a cooling liquid. According to this dicing apparatus, a cooling system to which the above-mentioned cooling liquid is supplied is disposed inside a casing that rotatably holds a spindle via an air bearing. By cooling the spindle with a cooling liquid, it is possible to suppress the rise in temperature of the spindle during machining, and as a result, it is possible to suppress the amount of thermal expansion of the spindle in the axial direction (Y-axis direction). Errors in the Y coordinate can be suppressed.

JP2007-088028A Japanese Patent Application Publication No. 2002-141307

However, in conventional dicing equipment, the temperature of the coolant that cools the spindle increases as the workpiece machining time passes, making it impossible to effectively suppress the thermal expansion of the spindle in the Y-axis direction. As a result, since the spindle is displaced in the Y-axis direction, there is a problem in that an error occurs in the Y coordinate of the blade, which is the processing means.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a processing device that can accurately control 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 device of the present invention includes a base member, a movable member movably provided on the base member, and a spindle motor supported by the movable member, the processing device being configured to move the movable member. A spindle motor having a spindle in the direction of the movement and a processing means attached to the spindle, a linear scale provided along the movement direction, a detector that moves together with the moving member and reads the value of the linear scale, and one end that moves. A thermal expansion member fixed to the member and having a detector fixed to the other end and capable of thermal expansion in the movement direction with one end as a first reference position, and cooling the spindle and the thermal expansion member with the same cooling liquid. A cooling system is provided.

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

According to one aspect of the invention, the length of the thermal expansion member in the direction of movement 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, and a unit temperature of the thermal expansion member from the second reference position on the spindle to the attachment position of the processing means. It is preferable to configure the amount of thermal expansion per temperature to be equivalent to or similar to the amount of thermal expansion.

According to one form of the present invention, the processing means is preferably a blade that grinds the workpiece.

According to the present invention, the position of the processing means in the axial direction of the spindle can be precisely controlled.

A perspective view showing the appearance of a dicing device according to an embodiment A perspective view showing the configuration of the processing section of the dicing device in Figure 1 An explanatory diagram showing the structure of the position detection device provided in the processing section in Fig. 2 An explanatory diagram of the spindle and thermal expansion member thermally expanding from the state shown in Figure 3 Illustration of thermal expansion of the spindle of a 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

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a processing apparatus according to the present invention will be described below with reference to the accompanying drawings. In the embodiment, a dicing device, which is an example of a processing device, 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 that processes a work W such as a semiconductor wafer, a cleaning section 14 that spin-cleans the processed work W, and a cassette that stores a large number of works W. It includes a load port 16 on which the work W is placed and a transport device 18 that transports the work W.

Note that this specification will be described using a three-dimensional orthogonal coordinate system in three axial directions (X-axis direction, Y-axis direction, and Z-axis direction). The X-axis direction shown in FIG. 1 is a horizontal direction, and indicates the cutting feed direction of an X-table 20 (see FIG. 2), which will be described later. Further, the Y-axis direction is a direction perpendicular to the X-axis direction in the horizontal direction, and refers to the index feeding direction of the blade 22, which will be described later. Further, the Z-axis direction is a vertical direction perpendicular to the X-axis direction and the Y-axis direction, and refers to 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 section 12 includes an X table 20 that is guided by a pair of X guide rails 26, 26 of an X base 24, and is 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 θ direction.

The work table 32 has, for example, a disk shape, and has a horizontally flat suction surface 34 on its upper surface, and the workpiece W (see FIG. 1) is vacuum suctioned and fixed to this suction surface 34. .

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 in front of the Y base 36. The Y tables 40, 40 are moved in the Y-axis direction by an unillustrated Y-axis drive mechanism 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. Further, 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). Spindle motors 46, 46 with built-in high-frequency motors are fixed to the Z tables 44, 44 facing each other in the Y-axis direction, and blades 22, 22 are mounted at the tips of the spindles 48, 48 of the spindle motors 46, 46 in the Y-axis direction. They are fixed facing each other at the These spindle motors 46, 46 are supported by the Y tables 40, 40 via the Z tables 44, 44, and the spindles 48, 48 have their axes aligned with the Y axis, which is the moving direction of the Y tables 40, 40. arranged along the direction.

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

According to the processing unit 12 configured in this manner, the work table 32 is cut and fed in the X-axis direction by the X table 20 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 cut and fed in the Z-axis direction by the Z-axis drive mechanism. The workpiece W is cut into a checkerboard pattern by such an operation of the processing unit 12.

The position detection device 50 that detects the current position (Y coordinate) of the blade 22 in the Y-axis direction will be described below with reference to FIG. 3. 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. 3, the position detection device 50 includes a linear scale 52 and a detector (also referred to as a reading head) 54. As shown in FIG. 2, the linear scale 52 is arranged in the Y-axis direction on the front of the Y base 36 along the Y guide rails 38, 38. 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, facing 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 one pulse every 1 μm to a control device (not shown) of the dicing device 10, for example. Then, the control device detects the current position of the blade 22 as a Y coordinate by counting the input pulse signals. Thereby, the current position of the blade 22 in the Y-axis direction can be detected. Note that since the position detection device consisting of a linear scale and a detector has a known configuration, a detailed explanation 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 cooling liquid flows along the arrow, as simply indicated by the bold line in FIG. 3, and a part of this conduit is disposed inside the spindle motor 46. The cooling system 60 also includes a pump 62, and the pump 62 supplies cooling fluid to the spindle motor 46 via a pipe line. Note that the configuration for cooling the inside of the spindle motor 46 as the cooling system 60 is not particularly limited, but for example, a configuration disclosed in Japanese Patent Laid-Open No. 2002-141307 can be adopted. .

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 detector 54 is fixed to the right end 56A of this thermal expansion member 56 in FIG. 3, and the left end 56B is fixed to the back surface of the Y table 40 by a fixing member 64. 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 shift 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, compared to the second reference position on the spindle 48, when the blade 22 is attached. It is configured to satisfy a condition (hereinafter referred to as "thermal expansion member condition") that is equal to or similar to the amount of thermal expansion per unit temperature up to the right end 48B, which is the position. Specifically, the length L of the thermal expansion member 56 in the Y-axis direction (the length from the left end 56B to the right end 56A) and the material are selected based on the amount of thermal expansion of the spindle 48. Note that the second reference position of the spindle 48 is a position that serves as a reference 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 characteristics of the spindle 48 (the amount of thermal expansion in the Y-axis direction per 1°C of coolant) are 10 μm/°C, and the material of the thermal expansion member 56 is SUS303 (specified by JIS standard (G4304:2015)). When using a linear expansion coefficient of 17.3 x 10-6/°C), the length L of the thermal expansion member 56 in the Y-axis direction is the same as the linear expansion coefficient of SUS303 (17.3 x 10-6/°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. In this way, when SUS303 is selected as the material of the thermal expansion member 56, the thermal expansion member condition can be satisfied by adopting a thermal expansion member 56 whose length L in the Y-axis direction is 0.58 m. can. Note that if there is a restriction on the length of the thermal expansion member 56, it is also possible to configure the thermal expansion member 56 to satisfy the thermal expansion member conditions by changing the material of the thermal expansion member 56. In addition, "approximation" in the thermal expansion member conditions refers to the ratio of the difference (absolute value) between the amount of thermal expansion of the spindle 48 and the amount of thermal expansion of the thermal expansion member 56 to the amount of thermal expansion of the spindle 48 (hereinafter referred to as "approximation"). (referred to as "expansion amount ratio") is within 30% (preferably within 20%). Furthermore, "equivalent" in the thermal expansion member conditions means that the thermal expansion rate 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 cooling fluid. 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 diagram showing a state in which both the spindle 48 and the thermal expansion member 56 have thermally expanded in the Y-axis direction from the state shown in FIG. 3 using two-dot chain lines. As shown in FIG. 4, in the embodiment, the temperature of the thermal expansion member 56 is approximately the same as the temperature of the spindle 48 by circulating the same cooling fluid between the spindle 48 and the thermal expansion member 56 by the cooling system 60. maintained 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 amounts of thermal expansion of both the spindle 48 and the thermal expansion member 56 are approximately the same. As a result, even if the blade 22 is displaced in the Y-axis direction due to thermal expansion of the spindle 48, the thermal expansion member 56 thermally expands by an amount corresponding to the amount of displacement, and due to the thermal expansion of the thermal expansion member 56, 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 at a position shifted in the Y-axis direction by an amount corresponding to the amount of displacement of the detector 54 due to thermal expansion of the spindle 48.

Therefore, in the embodiment, the value of the linear scale 52 is read by the detector 54 shifted in the Y-axis direction, 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 direction of displacement by an amount corresponding to the amount by which the detector 54 is shifted in the Y-axis direction (that is, the amount of displacement of the blade 22 in the Y-axis direction due to thermal expansion of the spindle 48). will be offset to the opposite side. In this embodiment, the thermal expansion of the spindle 48 is actively used to shift the position of the detector 54 by an amount corresponding to the displacement amount 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 precision.

Here, a comparative example to be compared with the embodiment will be described with reference to FIG. 5. FIG. 5 is an explanatory diagram schematically showing the structure of a processing section 100 as a comparative example. In explaining the processing section 100, members that are the same or similar in structure to the processing section 12 shown in FIGS. 3 and 4 are designated by the same reference numerals, and the explanation thereof will be omitted.

As shown in FIG. 5, the detector 54 in the comparative example is fixed to the Y table 40 via a rectangular parallelepiped-shaped block 102 that is shorter than the thermal expansion member 56 in the embodiment. The block 102 is made of a material having a smaller coefficient of thermal expansion than the material forming the thermal expansion member 56 of the embodiment. Further, the cooling system 104 in the comparative example does not supply the cooling liquid to the block 102, but is configured to supply the 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 due to 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 reading the value of the linear scale 52 with the detector 54 and trying to control the position of the blade 22 based on the reading result, the position of the blade 22 as described above is directly affected by the thermal expansion of the spindle 48. Misalignment occurs. Therefore, in the comparative example, it is difficult to accurately control the position of the blade 22.

Next, the experimental results of the processing section 100 of the comparative example shown in FIG. 5 and the processing section 12 of the embodiment shown in FIG. 3 will be explained with reference to the graphs shown in FIGS. 6 and 7. Note that the graph in FIG. 6 is the experimental result of the comparative example, and the graph in FIG. 7 is the experimental result of the processing section 12 of the embodiment.

In the graph shown in FIG. 6, the horizontal axis shows the elapsed processing time (minutes), the left vertical axis shows the temperature (° C.), and the right vertical axis shows 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 addition, in the graph of FIG. 6, the temperature change of the coolant in the comparative example is shown by line I, the temperature change of the block 102 is shown by line II, the temperature change of the spindle 48 is shown by line III, and the blade error amount The change in 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 increases (line III), and the temperature of the coolant gradually increases accordingly. There is (line I). On the other hand, since no cooling liquid is 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, and the blade error amount corresponding to the amount of positional displacement is It increases over 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 shown by line V, the temperature change of the thermal expansion member 56 is shown by line VI, the temperature change of the spindle 48 is shown by line VII, and the blade temperature change is shown by line VII. The change in the amount of error is shown by line VIII. Note that the horizontal axis, left vertical axis, and right vertical axis of the graph in FIG. 7 are the same as those in the graph in FIG. 6.

In the embodiment, as shown in FIG. 7, as the temperature of the spindle 48 gradually increases as the machining time passes (line VII), the temperature of the coolant gradually increases accordingly (line V), Further, 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 maintained at approximately the same temperature as the spindle 48. Therefore, as described above, the detector 54 is at a position shifted by an amount corresponding to the displacement amount of the blade 22 in the Y-axis direction due to the thermal expansion of the spindle 48, and therefore is affected by the thermal expansion of the spindle 48. Without this, the amount of blade error can be significantly reduced compared to the above-mentioned comparative example. Therefore, in the embodiment, since the influence of thermal expansion of the spindle 48 can be effectively canceled, the position of the blade 22 in the axial direction of the spindle 48 can be controlled with high precision.

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 condition, and the spindle 48 and the thermal expansion member 56 are at the same temperature. By having such a configuration, it is possible to effectively cancel the influence of thermal expansion of the spindle 48, making it possible to precisely control the position of the blade 22 in the axial direction of the spindle 48. .

Moreover, by employing the above configuration, it is also possible to eliminate the need for a temperature control chiller that controls 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-controlled chiller and increasing running costs of the temperature-controlled chiller. Note that the cooling system 60 may include a temperature-controlled chiller.

Further, in the embodiment, the thermal expansion member 56 is preferably formed of an elongated member, but the thermal expansion member 56 is not particularly limited as long as it has a thermal expansion amount comparable to that of the spindle 48. . Further, 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, but may be circular or polygonal. However, by configuring the thermal expansion member 56 as an elongated member, there is an advantage that the amount of thermal expansion of the thermal expansion member 56 due to temperature changes can be easily controlled.

Further, 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 so as to penetrate inside the thermal expansion member 56 may be used. The cooling system 60 may be fixed. Further, 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 as shown in FIGS. 3 and 4, but may be configured in which they are connected in parallel.

Further, in the embodiment, the dicing device 10 is illustrated as having the linear scale 52 and the detector 54 that detect the Y coordinate of the blade 22, but the present invention can be applied to processing devices other than the dicing device 10. can. For example, the present invention is applicable to any processing device equipped with a processing means such as a blade or a drill, provided that it is equipped with 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 it goes without saying that various improvements and modifications may be made without departing from the gist of the present invention. .

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

Claims (3)

a movable member provided movably;
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 processing means being attached to the spindle;
a linear scale provided along the moving direction;
a detector that moves together with the moving member and reads the value of the linear scale;
one end in the moving direction is fixed to the moving member, the detector is fixed to the other end opposite to the one end in the moving direction, and a thermal expansion member capable of thermal expansion in the moving direction; ,
Equipped with
The thermal expansion member is capable of thermally expanding in the movement direction by an amount corresponding to a displacement amount of the processing means in the movement direction due to thermal expansion of the spindle. 1 . The method of claim 1 , further comprising a control means for controlling the position of the processing means in the movement direction so that the amount of positional deviation of the processing means due to thermal expansion of the spindle is canceled based on the reading result of the detector. The processing equipment described in . The processing apparatus according to claim 1 or 2 , further comprising a temperature adjustment device that adjusts the spindle and the thermal expansion member to have the same temperature.

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