JP2012101291A - Machining method and machining apparatus for lens array die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining method and a machining apparatus for a lens array die, capable of machining the die used for creating the lens array, with high accuracy and efficiency.SOLUTION: The machining apparatus includes a machining machine A and a control device C. The machining machine A is configured including an X-axis moving mechanism 13X moving an X-table 11 in the X-axis direction in relation to a bed 1, a rotating mechanism 23 rotating a rotary table 21 provided on the X-table around a B-axis, and a Z-axis moving mechanism 33Z and a Y-axis moving mechanism 43Y moving a tool spindle 60 having a machining tool T at the leading end thereof in the Z- and Y-axis directions. The control device controls the rotating mechanism and X-axis moving mechanism with a rotation center of the rotary table as a machining reference, and controls the Z-axis moving mechanism and Y-axis moving mechanism to machine a lens shape on a workpiece.

Description

    The present invention relates to a lens array mold processing method and processing apparatus. For example, the present invention relates to a processing method and a processing apparatus for a lens array mold having a plurality of lens shapes having a relatively large area.

The use of lens arrays has been expanding in recent years, and in particular, lens arrays used for optical elements manufactured at the wafer level are highly demanded, and it is an urgent issue to study high-precision and high-efficiency processing of molds used therefor. It has become. In this processing, not only the processing quality of each lens shape but also the positional accuracy and the uniformity of processing quality are regarded as important.
Conventionally, attempts have been made to deal with such problems using an ultra-precision processing machine based on three orthogonal axes (X, Y, Z axes). (For example, refer to Patent Document 1).

JP 2010-115741 A

However, even with the use of ultra-precision processing machines based on three orthogonal axes (X, Y, Z axes), submicron order position accuracy and uniformity of processing quality are obtained in long-time machining over several days. It is not easy.
In addition, it is difficult to exchange tools and workpieces, and there is a problem that machining efficiency tends to decrease. That is, in lathe processing, the center of rotation of the work spindle is the processing center, so the center of the workpiece and the tool tip can be aligned with the rotation center of the work spindle. Because there is no specific machine reference for workpieces and tools, it is necessary to check the mutual position of the tool center and workpiece reference point for each workpiece, for example, to replace the touch probe and check the workpiece coordinates. Become. However, in the case of ultra-precision machining, an error of micron order due to attachment / detachment of a tool is not allowed, so that the work coordinates cannot be confirmed by replacing with the touch probe as described above. Accordingly, since the machining must be performed with some allowance for machining allowance, the removal amount increases correspondingly, and the machining efficiency decreases.

  An object of the present invention is to solve such problems and to provide a processing method and a processing apparatus for a lens array mold capable of processing a mold used for producing a raise array with high accuracy and high efficiency.

  The lens array mold processing method of the present invention is a lens array mold processing method for processing a plurality of lens shapes on a workpiece, and includes a bed, a reciprocating table provided on the bed, and the reciprocating table. A first moving mechanism for moving the moving table in the first axial direction with respect to the bed, a rotary table rotatably provided on the reciprocating table, and the rotary table in the first axial direction A rotation mechanism that rotates about an axis orthogonal to the rotation table, a tool spindle that is rotatable about an axis parallel to the rotation axis of the rotary table, and the tool spindle with respect to the first axial direction. Preparing a processing machine having a second moving mechanism and a third moving mechanism that move in the second and third axial directions orthogonal to each other and orthogonal to each other; A set-up step in which a machining tool is attached to the tip of the tool spindle and the tip of the machining tool is positioned at the rotation center of the rotary table, and the rotation in which the tip of the machining tool is located. Using the rotation center of the table as a processing reference, the workpiece is rotated and moved in the first axial direction by the rotating mechanism and the first moving mechanism, and the processing tool is moved by the second and third moving mechanisms. And a machining step of machining a lens shape on the workpiece while moving in the second and third axial directions.

According to this configuration, a processing machine having a rotary table and a tool spindle is prepared (preparation process), a work is placed on the rotary table, a processing tool is attached to the tip of the tool spindle, and the tip of the processing tool is attached. It is positioned at the rotation center of the rotary table (setup process).
The workpiece is rotated and moved in the first axial direction by rotating the rotary table and moving the reciprocating table using the rotation center of the rotary table at which the tip of the processing tool is positioned as a processing reference, and the second and third axes. The workpiece is moved in the second and third axial directions by the moving mechanism to process the lens shape on the workpiece (processing step).

  That is, since the rotation center of the rotary table that has the least thermal influence that causes a large error in long-time processing is used as the processing reference, the lens array mold can be processed with high accuracy. In addition, since the work is placed on the rotary table and the processing tool is attached to the tool spindle, the work is placed on the center of rotation of the rotary table while rotating the rotary table. In addition, it is not difficult to align the processing tool with the rotary table rotation center even if it is less than 1 micron from the lathe processing know-how, so the lens array mold can be processed with high efficiency.

  A lens array mold processing apparatus according to the present invention is a lens array mold processing apparatus that processes a plurality of lens shapes on a workpiece, and includes a processing machine that processes the workpiece, and a control device that controls the processing machine. The processing machine includes a bed, a reciprocating table provided on the bed, a first moving mechanism for moving the reciprocating table with respect to the bed in a first axial direction, A rotary table that is rotatably provided on a reciprocating table and places a workpiece on an upper surface thereof, a rotary mechanism that rotates the rotary table about an axis orthogonal to the first axial direction, and the rotary table A tool spindle which is rotatably provided around an axis parallel to the rotation axis of the tool and has a machining tool at the tip, and a tool spindle which is perpendicular to the first axial direction and perpendicular to each other. And a second moving mechanism that moves in the third axial direction and a third moving mechanism, and the control device uses the rotation center of the rotary table at which the tip of the processing tool is positioned as a processing reference. The rotating mechanism and the first moving mechanism are controlled, and the second moving mechanism and the third moving mechanism are controlled to process the lens shape on the workpiece.

  According to this configuration, like the lens array mold processing method described above, the rotation center of the rotary table that has the least thermal influence that causes a large error in long-time processing is used as the processing reference. Can be processed with high accuracy. In addition, since the work is placed on the rotary table and the processing tool is attached to the tool spindle, the work is placed on the center of rotation of the rotary table while rotating the rotary table. In addition, it is not difficult to align the processing tool with the rotary table rotation center even if it is less than 1 micron from the lathe processing know-how, so the lens array mold can be processed with high efficiency.

In the lens array mold processing apparatus of the present invention, it is preferable that the processing apparatus includes a housing that covers the entire processing machine and that can be temperature-controlled.
In general, when machining is performed for a long period of time, error factors due to temperature changes in the surrounding environment and heat generated from the tool spindle affect the machining accuracy.
According to the present invention, when machining is performed for a long time, even if there is a temperature change in the surrounding environment, the inside of the housing is temperature-controlled, so that the influence on the machining accuracy can be reduced.

In the lens array mold processing apparatus of the present invention, it is preferable that the tool spindle is provided with a temperature control mechanism capable of temperature control.
According to the present invention, even when heat is generated from the tool spindle when machining is performed for a long time, the temperature of the tool spindle is controlled by the temperature control mechanism provided on the tool spindle. Less.

The perspective view which shows the processing apparatus which concerns on embodiment of this invention. The figure which shows the C-axis turning mechanism and tool spindle of the processing machine of the said embodiment. The figure which shows a mode that the lens array metal mold | die is processed with the processing machine of the said embodiment. The front view which shows the heat transfer path | route in the processing machine of the said embodiment. The side view which shows the heat transfer path | route in the processing machine of the said embodiment. The figure which shows the reproducibility error (+ direction) of the rotary table of the processing machine of the said embodiment. The figure which shows the reproducibility error (-direction) of the rotary table of the processing machine of the said embodiment. The figure which shows the effect of the Example of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Description of processing apparatus (see FIG. 1)>
As shown in FIG. 1, the processing apparatus of the present embodiment includes a processing machine A that processes a workpiece W, a casing B that covers the entire processing machine A and that can be temperature-controlled inside, and driving the processing machine A. And a control device C for controlling.

  The processing machine A includes a bed 1, an X table 11 as a reciprocating table provided on the front side of the upper surface of the bed 1 so as to be capable of reciprocating in the X-axis direction as the first axial direction, The rotary table 21 is provided to be rotatable about an axis (B axis) orthogonal to the X-axis direction, and is provided to be rotatable about an axis parallel to the rotary axis (B axis) of the rotary table 21. And a tool spindle 60 having a processing tool T such as an end mill at the tip, and the tool spindle 60 in the Z-axis direction and the Y-axis direction as second and third axis directions orthogonal to the X-axis and orthogonal to each other. A tool moving mechanism 30 that moves and pivots about an axis parallel to the Z axis (C axis), and a view provided on the bed 1 adjacent to the tool moving mechanism 30 so that the upper surface of the rotary table 21 can be observed. And a device 70.

  Between the bed 1 and the X table 11, an X axis guide mechanism 12X and an X axis moving mechanism 13X for guiding and driving the X table 11 in the X axis direction are provided. The X-axis guide mechanism 12X includes a V groove formed in the bed 1, a triangular ridge formed on the X table 11 corresponding to the V groove, and an inclined surface between the V groove and the ridge. It is comprised by the VV rolling guide mechanism which has the roller interposed in. The X-axis moving mechanism 13X is configured by a linear motor mechanism.

  Between the rotary table 21 and the X table 11, a rotary mechanism 23 that rotates the rotary table 21 around the B axis is provided. The rotation mechanism 23 is configured by a rotation mechanism having a rotation drive source such as a motor, for example.

  The tool moving mechanism 30 includes a Z table 31 provided on the rear side of the upper surface of the bed 1 so as to be movable in the front-rear direction (Z-axis direction), a column 34 fixed to the upper surface of the Z table 31, A Y-slider 41 provided so as to be movable in the vertical direction (Y-axis direction) along the axis, and a tool spindle 60 provided at the tip of the Y-slider 41 so as to be rotatable about an axis (C-axis) parallel to the Z-axis direction. And a C-axis turning mechanism 50 to which is attached.

Between the bed 1 and the Z table 31, there are provided a Z-axis guide mechanism 32Z and a Z-axis moving mechanism 33Z for guiding and driving the Z table 31 in the Z-axis direction. The Z-axis guide mechanism 32Z and the Z-axis movement mechanism 33Z are configured by a VV rolling guide mechanism and a linear motor mechanism, similarly to the X-axis guide mechanism 12X and the X-axis movement mechanism 13X.
Between the column 34 and the Y slider 41, a Y axis guide mechanism 42Y and a Y axis moving mechanism 43Y for raising and lowering the Y slider 41 in the Y axis direction are provided. The Y-axis guide mechanism 42Y is configured by a VV rolling guide mechanism, similarly to the X-axis guide mechanism and the Z-axis guide mechanism. The Y-axis moving mechanism 43Y is configured by a pair of cylinder mechanisms 44 provided at the upper end of the column 34 and capable of moving the Y slider 41 up and down and positioning it at an arbitrary position.

  The observation device 70 includes a support 71 standing on the rear side of the upper surface of the bed 1, a guide rail 72 supported on the upper end of the support 71 and extending along the Z-axis direction, and a Z-axis direction along the guide rail 72. And a microscope 73 supported so as to be movable. The microscope 73 has a built-in lens, illumination, camera, and the like, and is connected to a personal computer, so that an image captured by the camera can be enlarged and displayed on the personal computer, and a dimension can be measured from the captured image. It has become.

  The housing B is formed in a size that covers the entire processing machine A, and has an air supply port 81 and an air discharge port 82. Air from a temperature adjustment air supply device (not shown) having a temperature adjustment function is supplied to the inside of the housing B through the air supply port 81. The air supplied to the inside of the housing B circulates inside the housing B, is then discharged from the air discharge port 82 to the outside of the housing B, and is returned to the temperature adjustment air supply device. As a result, the internal temperature of the housing B is controlled to + 0.02 ° C. to −0.02 ° C. with respect to the set temperature.

  The control device C controls the drive of the processing machine A according to a preset processing program. Specifically, in a state where the tip of the processing tool T is positioned at the center of the rotary table 21, the rotation table 21 is rotated, the X table 11 is moved, and the Z table 31 is rotated using the rotation center of the rotary table 21 as a processing reference. The movement, the movement of the Y slider 41, and the turning operation of the tool spindle 60 are controlled. That is, the rotating mechanism 23, the X-axis moving mechanism 13X, the Z-axis moving mechanism 33Z, the Y-axis moving mechanism 43Y, and the C-axis turning mechanism 50 are controlled.

<Description of C-axis turning mechanism and tool spindle (see FIG. 2)>
As shown in FIG. 2, the C-axis turning mechanism 50 includes a rotary shaft 51 that can rotate around the C-axis, a chuck 52 that can be opened and closed at the tip of the rotary shaft 51, and a rotary shaft 51. And a cooling fluid circulation path 53 as a temperature control mechanism formed. A fluid such as air or water whose temperature is adjusted is circulated through the cooling fluid circulation path 53.
As shown in FIG. 2, the tool spindle 60 has a tool main body 62 having an arm 61 that is detachably held by the chuck 52, and is provided on the tool main body 62 so as to be rotatable by a driving source such as a motor. A spindle 63 with T attached thereto and a cooling fluid circulation path 64 as a temperature control mechanism formed inside the tool body 62 around the spindle 63 are configured. A fluid such as air or water whose temperature is adjusted is circulated in the cooling fluid circulation path 64. Thereby, the temperature of the tool spindle 60 including the C-axis turning mechanism 50 is controlled to + 0.05 ° C. to −0.05 ° C. with respect to the set temperature.

<Lens array mold processing method (see FIG. 3)>
First, the tip of the processing tool T is positioned at the rotation center of the rotary table 21. For this purpose, the X table 11 is moved in the X-axis direction, the Z table 31 is moved in the Z-axis direction, the tip of the machining tool T is positioned at the rotation center of the rotation table 21, and the rotation center of the rotation table 21 is moved. Is set as the processing standard.
Here, in order to process the lens shape at the processing point offset from the center position of the rotary table 21 on the upper surface of the work W, the X table 11 is moved in the X axis direction and the Z table 31 is moved in the Z axis direction. Move. Alternatively, after rotating the rotary table 21 by 180 degrees, the X table 11 is moved in the X axis direction and the Z table 31 is moved in the Z axis direction. Further, after rotating the rotary table 21 by an angle formed by a line connecting the rotation center of the rotary table 21 to the machining point and an X-axis line passing through the rotation center, the distance from the rotation center of the rotary table 21 to the machining point. Only the X table 11 is moved. Then, a processing point is located directly under the processing tool T.

In this state, as shown in FIG. 3, the X table 11 is moved in the X-axis direction, the machining tool T is moved in the Z-axis direction and the Y-axis direction, and the machining tool T is spirally moved with respect to the workpiece W. However, the lens shape is processed at the processing point of the workpiece W by moving the lens gradually closer to the center.
Therefore, since the rotation center of the turntable 21 that has the least thermal influence that causes a large error during long-time machining is used as a machining reference, the lens array mold can be machined with high accuracy. Further, since the work W is placed on the rotary table 21 and the processing tool T is attached to the tool spindle 60, the work W and the processing tool T can be exchanged efficiently. Therefore, the lens array mold can be processed with high efficiency.

<Description of heat transfer path (see FIGS. 4 and 5)>
A positional error in long-time machining is considered to be caused by a thermal effect. FIG. 4 and FIG. 5 show the locations where the thermal influence is clarified on the path from the machining point to each of the X, Y, and Z axis position detectors, for example, the linear encoders SX, SY, and SZ. become.
EX1 path = work → rotation table → X table → X axis linear scale EX2 path = machining tool → tool spindle → Y axis → bed → X axis linear scale EZ1 path = work → rotation table → X table → bed → Z axis linear scale EZ2 path = machining tool → tool spindle → C axis turning mechanism → Y axis → Z axis linear scale EY1 path = work → rotation table → X table → bed → Y axis → Y axis linear scale EY2 path = machining tool → tool spindle → C-axis turning mechanism → Y-axis linear scale

For the positioning of the processing tool T and the workpiece W, the indicated values of the linear encoders SX, SY, and SZ are referred to through the X, Y, and Z axis directions and the B and C axis systems. Among these, the main thermal factors include changes in the ambient temperature and heat generation from the tool spindle 60.
In the present embodiment, since the entire processing machine A is covered with the casing B capable of controlling the internal temperature, the inside of the casing B is maintained even if there is a temperature change in the surrounding environment when processing is performed for a long time. Since the temperature is controlled, the influence on machining accuracy can be reduced.

Even if the temperature management in the housing B is not sufficient, a member having a large heat capacity such as the bed 1 or the column 34 has a small degree of thermal influence on the temperature change in the surrounding environment, but the C-axis turning mechanism 50 or the like. A member close to the heat source and having a small heat capacity is considered to increase the degree of thermal influence.
In contrast, in this embodiment, since the cooling fluid circulation paths 53 and 64 are provided in the C-axis turning mechanism 50 and the tool spindle 60, there is no heat generation from the tool spindle 60 when machining is performed for a long time. However, the thermal influence can be suppressed. Therefore, the influence on the processing accuracy can be reduced.

<Positioning repeatability of rotary table (see FIGS. 6 and 7)>
On the other hand, in the lens array mold to be processed, the target values of horizontal position accuracy of +0.5 to −0.5 μm or less and processing depth of about +1 to −1 μm or less are often indicated. It is necessary to place importance on the positioning accuracy in the horizontal direction.
In this embodiment, since the rotary table 21 is mounted on the X table 11, the reproducibility of the indexing accuracy of the rotary table 21 affects the horizontal position accuracy. Accordingly, a reference plane of 200 mm is fixed on the rotary table 21, the rotary table 21 is repeatedly positioned at 180 degrees, and an inclination error obtained by scanning the electric micrometer parallel to the X axis is evaluated. 6 and FIG. 7 were obtained.
As a result, a reproducibility of about 0.05 μm at 200 mm is obtained, so it is considered that the required positioning accuracy can be accommodated.

<Other effects>
In addition, since the observation device 70 capable of observing the upper surface of the rotary table 21 is provided, the tip of the machining tool is always adjusted to the same coordinate position even if the machining tool needs to be replaced due to the tool life during long-time machining. can do. For example, by performing trial machining at the rotation center of the rotary table 21 and confirming the positional accuracy with the microscope 73, the blade edge of the replaced processing tool T can be accurately positioned at the rotation center of the rotary table 21.

  In addition, since a linear motor mechanism is used as the X-axis moving mechanism 13X and the Z-axis moving mechanism 33Z, the power consumption is very small while being high torque. Also, as the X-axis guiding mechanism 12X and the Z-axis guiding mechanism 32Z, Since a V-V rolling guide mechanism having high guide surface rigidity is employed together, high control characteristics can be obtained.

<Modification>
In addition, this invention is not limited to the said embodiment, The deformation | transformation in the range which can achieve this invention, improvement, etc. are contained in this invention.
For example, in the above embodiment, the tool spindle 60 is detachably attached to the rotating shaft 51 of the C-axis turning mechanism 50 via the chuck 52, but the tool spider 60 is firmly fixed to the rotating shaft 51 with a bolt or the like. If this is done, more accurate machining can be expected.

  Moreover, in the said embodiment, although the shape processed into the workpiece | work W was measured with the microscope 73, you may make it measure not only this but the processed shape by laser measurement, white interference measurement, etc. Good.

<Example (see FIG. 8)>
The effectiveness of the processing method of the lens array mold by the processing apparatus was verified. Processing positions and evaluation results are shown in FIG.
As a verification procedure, first, the machining tool T and the workpiece W are aligned with the rotation center of the rotary table 21 serving as a machining reference, and three lens shapes (concave spherical surfaces) are machined at positions offset from the rotation center. Next, the rotary table 21 was rotated 180 degrees, and three lens shapes (concave spherical surfaces) were processed again. The same operation was performed 5 times every 24 hours.
Evaluation of the machining position was performed using a three-dimensional shape measuring instrument (UA3P, manufactured by Panasonic), with the first machining position set to zero error, and the difference between the measurement position and the machining instruction position was evaluated. Although it is considered that there are some uncertainties in evaluation such as thermal expansion of the workpiece due to temperature difference during measurement and measurement reproducibility, the machining position error is about 0.2 μm or less in both the X-axis direction and Z-axis direction. Good results were obtained.

  The present invention can be used for a processing method of a lens array mold having a plurality of lens shapes having a relatively large area.

1 ... bed,
11 ... X table (reciprocating table),
13X ... X-axis moving mechanism,
21 ... Rotary table,
23 ... rotation mechanism,
33Z ... Z-axis moving mechanism,
43Y ... Y-axis moving mechanism,
53. Cooling fluid circuit (temperature control mechanism),
60 ... Tool spindle,
64 ... Cooling fluid circuit (temperature control mechanism),
A ... Processing machine,
B ... Case,
C: Control device,
T ... Machining tool,
W ... Work.

Claims (4)

A method of processing a lens array mold for processing a plurality of lens shapes on a workpiece,
A bed, a reciprocating table provided on the bed, a first moving mechanism for moving the reciprocating table relative to the bed in a first axial direction, and rotatable on the reciprocating table A rotary table provided on the rotary table, a rotary mechanism for rotating the rotary table around an axis orthogonal to the first axis direction, and a rotary table provided rotatably about an axis parallel to the rotary axis of the rotary table. And a second moving mechanism and a third moving mechanism for moving the tool spindle in second and third axial directions orthogonal to the first axial direction and orthogonal to each other. A process for preparing a processing machine,
A step of placing the workpiece on the rotary table, attaching a processing tool to the tip of the tool spindle, and positioning the tip of the processing tool at the rotation center of the rotary table;
The rotation center and the first movement mechanism are used to rotate and move the workpiece in the first axial direction with the rotation center of the rotary table at which the tip of the machining tool is positioned as a machining reference, and the second and And a machining step of machining a lens shape on the workpiece while moving the machining tool in the second and third axial directions by a third moving mechanism. Method. A lens array mold processing apparatus for processing a plurality of lens shapes on a workpiece,
A processing machine for processing the workpiece, and a control device for controlling the processing machine,
The processing machine includes a bed, a reciprocating table provided on the bed, a first moving mechanism for moving the reciprocating table in the first axial direction with respect to the bed, and the reciprocating table. A rotary table that is rotatably provided on the upper surface and places a work on the upper surface, a rotary mechanism that rotates the rotary table about an axis orthogonal to the first axial direction, and a rotary shaft of the rotary table And a tool spindle having a machining tool at the tip thereof, which is rotatable about an axis parallel to the axis, and the second and third axis directions perpendicular to the first axis direction and perpendicular to each other. A second moving mechanism to be moved and a third moving mechanism;
The control device controls the rotation mechanism and the first movement mechanism using a rotation center of the rotary table at which the tip of the machining tool is positioned as a machining reference, and also controls the second movement mechanism and the third movement mechanism. An apparatus for processing a lens array mold, wherein a lens shape is processed on the workpiece by controlling a moving mechanism. The lens array mold processing apparatus according to claim 2,
An apparatus for processing a lens array mold, comprising: a casing that covers the whole of the processing machine and whose inside can be temperature-controlled. In the lens array mold processing apparatus according to claim 2 or 3,
The tool spindle is provided with a temperature control mechanism capable of controlling the temperature, and the lens array mold processing apparatus.

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