JP2013186291A - Exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-sided exposure device with high positioning accuracy of front-side and back-side faces.SOLUTION: A double-sided exposure device 100 performs exposure by plural laser beams including a first laser beam and a second laser beam irradiated in a direction different from the first laser beam, includes a sensor 16 for detecting an irradiation position of the first laser beam and a sensor 26 for detecting an irradiation position of the second laser beam, makes an irradiation position to be a base of the first laser beam detected by the sensor 16 match an irradiation position of the second laser beam detected by the sensor 26, and makes the first laser beam and the second laser beam irradiated to an exposed member.

Description

  The present invention relates to an exposure apparatus.

Generally, a printed circuit board used for an electronic device is manufactured by drawing a metal wiring pattern on the front and back of an insulating substrate. In addition, MEMS (Micro Electro Mechanical Systems) devices that make up various sensors and actuators are three-dimensionally processed piezoelectric materials, ferroelectric materials, magnetic materials, silicon substrates, glass substrates, quartz substrates, etc. It is formed as a movable structure. As electronic devices using these devices are continuously pursued for portability, high functionality, and low power consumption, constituent devices are increasingly required to be miniaturized and highly accurate. Therefore, even in an apparatus for manufacturing a printed circuit board or a MEMS device, there is a problem of high processing accuracy while maintaining throughput and processing cost. In particular, there is a high need for an exposure apparatus related to photolithography that affects accuracy, and improvement in processing accuracy of the front and back of the substrate and improvement of throughput in the front and back integrated processing are problems.
For example, when exposing the photoresist by optically projecting the necessary pattern information on the front and back surfaces of the substrate as a mask, in order to ensure the projection position accuracy of the front and back surfaces, There is known a method for recognizing the position of a mark formed on one surface through infrared transmission from the other surface. Further, for example, as described in Patent Document 1, a method of performing exposure while maintaining high alignment accuracy of front and back patterns using a single-sided exposure machine with the edges of two orthogonal sides of a correctly diced substrate as reference surfaces It has been known.

JP-A-6-43658

  However, the conventional techniques described above have problems such as complicated processes and limitations in alignment accuracy. Specifically, the problem is that throughput cannot be increased because each side is processed, and when a reference through hole is used, there is a process for forming a highly accurate through hole and a substrate space for forming the through hole. The problem was that it was necessary. In addition, regarding the accuracy of alignment, the method of infrared fluoroscopy cannot perform image recognition with high resolution, and the method described in Patent Document 1 performs alignment each time each surface is processed. The problem is that the error becomes large.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 An exposure apparatus according to this application example scans the second laser light from a direction different from the irradiation direction of the first optical path and the first optical path that scans and irradiates the first laser light. A first optical sensor that detects an end of the irradiation position of the first laser light, and an end of the irradiation position of the second laser light. An irradiation position of the second laser light detected by the second sensor at an end of an irradiation position as a reference of the first laser light detected by the first sensor. After the ends are aligned, the exposed member is irradiated with the first laser light and the second laser light.

  According to this application example, in order to align the end of the irradiation position of the second laser light detected by the second sensor with the end of the irradiation position serving as the reference of the first laser light detected by the first sensor, The first laser beam and the second laser beam are irradiated to the same position (common irradiation position) from different directions. With this arrangement, the member to be exposed is exposed at the same position (common irradiation position) by a plurality of laser beams (first laser beam and second laser beam) irradiated from different directions. In the case where the member is a flat plate, exposure can be performed with irradiation light from the front and back of the flat plate, and the irradiation position of the second laser beam can be directly matched to the irradiation position of the first laser beam. More specifically, the alignment accuracy of each laser beam can be further increased.Specifically, for example, when the irradiation is performed from the front and back of a flat plate, when the alignment is performed independently for each side, the accumulated error ( In the case of this application example, the error is suppressed within the range of the alignment error of the second laser beam with respect to the first laser beam. Moreover, there is no need to provide a common alignment mark on the front and back surfaces of the flat plate or a through-hole for positioning.Therefore, in the case of a flat plate, the application area to the product can be secured to the maximum, Manufacturing efficiency can be increased.

  Application Example 2 In the exposure apparatus according to the application example, the first optical path that scans the first laser light in a one-dimensional direction and the second optical path that scans the second laser light in a one-dimensional direction. And the irradiation position used as the reference of the laser light in the first optical path is distributed along a one-dimensional space of the laser light in the second optical path.

  According to this application example, the exposure position as the reference of the laser light in the first optical path is distributed along the one-dimensional space of the laser light in the second optical path, so that the exposed member is irradiated from different directions. The common irradiation position is exposed by a plurality of laser beams scanned in a one-dimensional direction (hereinafter referred to as laser scanning light). For example, when the member to be exposed is a flat plate, it is possible to expose with laser scanning light from the front and back of the flat plate. Further, since the irradiation position of the laser scanning light as the second laser light can be directly aligned with the irradiation position of the laser scanning light as the first laser light, the alignment of the laser scanning light is similar to the above application example. Can be performed with higher accuracy.

  Application Example 3 In the exposure apparatus according to the application example described above, the first sensor is a pair of photosensors that detect irradiation positions at both ends of a one-dimensional space irradiated with the laser light of the first optical path, The second sensor is a pair of photosensors that detect irradiation positions at both ends of the one-dimensional space irradiated with the laser light in the second optical path.

  As in this application example, each of the first sensor and the second sensor is preferably configured by a pair of photosensors. By detecting the irradiation positions at both ends of the scanning line by the laser light, the positions of the one-dimensional space of the first laser light and the one-dimensional space of the second laser light can be easily detected.

  Application Example 4 In the exposure apparatus according to the application example described above, the scanning unit for the first optical path and the second optical path includes a polygon mirror.

  As in this application example, the laser beam scanning unit preferably includes a polygon mirror. By using the polygon mirror, the laser beam scanning means can be configured more simply.

  Application Example 5 In the exposure apparatus according to the application example described above, the exposure apparatus includes a sub-scanning unit that moves the exposed member in a direction that intersects a one-dimensional space that constitutes an irradiation position that is a reference of the first laser beam. It is characterized by.

  According to this application example, the image forming apparatus further includes a sub-scanning unit that moves the exposed member in a direction that intersects the one-dimensional space that configures the irradiation position that is the reference of the first laser beam. It is possible to provide an exposure apparatus that performs high-precision exposure as a surface.

  Application Example 6 In the exposure apparatus according to the application example described above, the first laser beam and the second laser beam are modulated by the same data and are irradiated substantially simultaneously.

  According to this application example, it is possible to irradiate the same position (common irradiation position) from different directions at the same time with similarly modulated laser light. As a result, for example, when the exposed member is a flat plate, it is possible to expose from the front and back of the flat plate at the same time, and the same image on the front and back (the image that overlaps when viewed in plan) is minimized. Can be drawn.

  Application Example 7 In the exposure apparatus according to the application example, the sub-scanning unit includes an articulated robot.

  By using an articulated robot as the sub-scanning means as in this application example, it is possible to provide an exposure apparatus that can set the exposure range more flexibly and simply.

1 is a conceptual diagram illustrating an irradiation mechanism of a double-sided exposure apparatus according to Embodiment 1. FIG. The perspective view which shows the method of detecting the position of main scanning. (A), (b) Explanatory drawing of a sensor. (A) The side view which shows the installation position of the sensor in a double-sided exposure apparatus, (b) The perspective view which shows a mode that 1st scanning light and 2nd scanning light are irradiated to a common irradiation position. The side view which shows the scanning light which injects into the side surface of a to-be-exposed member. (A) Explanatory drawing which shows the to-be-exposed part of the exposure apparatus which concerns on the modification 1, (b) The perspective view which shows the articulated robot as a subscanning means which concerns on the modification 1. FIG.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding.

(Embodiment 1)
First, the double-sided exposure apparatus 100 as the exposure apparatus according to the first embodiment will be described.
FIG. 1 is a conceptual diagram for explaining an irradiation mechanism of the double-sided exposure apparatus 100.
The double-sided exposure apparatus 100 includes laser light sources 11 and 21, mirrors 12 and 22, polygon mirrors 13 and 23 as first and second scanning means, fθ lenses 14 and 24, half mirrors 15 and 25, first and second. The sensors 16 and 26 as the sensors, the holding unit 30, the laser control unit 50, and the like are included.

  The double-sided exposure apparatus 100 uses a laser light source 11 as a light source to irradiate laser scanning light onto the surface 1a of the substrate 1 as an exposed member, and a laser light source 21 as a light source to emit laser scanning light onto the back surface 1b. It has two optical paths, the second optical path to irradiate.

The laser light sources 11 and 21 emit modulated laser light (laser beam) under the control of the laser control unit 50. Laser light emitted from the laser light sources 11 and 21 is converted into laser scanning light that is scanned in a one-dimensional direction by the polygon mirrors 13 and 23. The first optical path includes a mirror 12, a polygon mirror 13, an fθ lens 14, and the like, and laser scanning light (hereinafter referred to as first scanning light) using the laser light source 11 as a light source scans and exposes the surface 1a of the substrate 1. . The second optical path includes a mirror 22, a polygon mirror 23, an fθ lens 24, and the like, and laser scanning light (hereinafter referred to as second scanning light) using the laser light source 21 as a light source scans the back surface 1b of the substrate 1 for exposure. .
Hereinafter, scanning of the front and back surfaces of the substrate 1 with the first and second scanning lights is referred to as main scanning.

  The polygon mirrors 13 and 23 are rotary polygon mirrors that are driven to rotate by a motor. An encoder (not shown) for detecting the rotation angle and rotation amount is provided, and the scanning timing of the first and second scanning lights is controlled by rotating under the control of the laser controller 50. The two sets of polygon mirrors rotate in directions opposite to each other.

The irradiation position on the surface 1a by the first scanning light is set by adjusting the mirror 12, the polygon mirror 13, the fθ lens 14 and the like as the common irradiation position. The irradiation position on the back surface 1b by the second scanning light is adjusted to the common irradiation position by adjusting the mirror 22, the polygon mirror 23, the fθ lens 24, etc., and the first scanning light and the second scanning modulated by the laser control unit 50 are used. It is set so that the light is irradiated at the same position in synchronization. These synchronous irradiation settings are performed by adjusting the optical axes detected by the half mirrors 15 and 25 and the sensors 16 and 26.
In this embodiment, the mechanism for oscillating the polygon mirror in reverse is exemplified as the mechanism for oscillating the laser. However, a uniaxial carbano mirror, a MEMS scan mirror, or the like may be used.

  The end of the substrate 1 is held by a holding unit 30 that constitutes a part of sub-scanning means (not shown), and the exposed portion of the substrate 1 is irradiated with the first scanning light and the second scanning light. It is thrown into the irradiation position. The holding unit 30 moves in a direction crossing the main scanning direction by driving the sub-scanning means. The substrate 1 moves in a direction crossing the main scanning direction as the holding unit 30 moves. Hereinafter, the movement of the substrate 1 accompanying the movement of the holding unit 30 is referred to as sub-scanning.

  With the above configuration, the front and back surfaces of the substrate 1 to be sub-scanned are irradiated with laser scanning light based on the control of the laser control unit 50 in synchronization, and the front and back surfaces of the substrate 1 are exposed.

Next, synchronous irradiation in which the first scanning light and the second scanning light are synchronized and irradiated to the common irradiation position will be specifically described including the method.
FIG. 2 is a perspective view showing a method for detecting the position of main scanning.
In FIG. 2, a space (line space) from point A to point B shows a common irradiation position Ls, and the other end B of the common irradiation position Ls from the laser light La that irradiates one end A point of the common irradiation position Ls. A state in which the first scanning light scans up to the laser beam Lb that irradiates the point is shown. In addition, a pair of photosensors that detect the respective irradiation positions (laser beam irradiation points) at positions exceeding the common irradiation position Ls (downward in the drawing) are provided at the respective irradiation destinations of the laser light La and the laser light Lb. 16a is arranged.
As shown in the figure, the description will be made assuming that the main scanning direction is the X-axis direction and the sub-scanning direction is the Y-axis direction.

In order to synchronize the first scanning light and the second scanning light with the common irradiation position Ls, first, the irradiation position (scanning range) of the first scanning light set in a specific range on the X axis is set to the common irradiation position Ls. Detect as. Next, the irradiation position (scanning range) of the second scanning light is adjusted to the detected common irradiation position Ls. Next, a laser beam having a synchronized timing is emitted from each of the laser light sources 11 and 21 based on the control of the laser control unit 50, and the polygon mirrors 13 and 23 are rotated in synchronization to thereby generate the first scanning light and the first scanning light. Two scanning lights are irradiated synchronously.
Hereinafter, it demonstrates concretely in order.

The scanning range of the first scanning light can be obtained by detecting the beam irradiation points of the laser beams La and Lb constituting both ends thereof with high accuracy. A photo sensor 16a is used for detecting the beam irradiation point.
3A and 3B are explanatory diagrams of the photosensor 16a.
As shown in FIG. 3A, a quadrant photodiode 16a1 is used for the photosensor 16a. By obtaining the output Da, Db, Dc, Dd of each photodiode by the irradiated laser light, the position (beam irradiation point) irradiated on the four-division photodiode 16a1 is used as displacement information on the X and Y axes. Can be calculated. Since the accuracy of position detection depends on the accuracy of the 4-division photodiode 16a1, it is preferable to select a 4-division photodiode having a necessary and sufficient accuracy.

  Note that the photosensor 16a is not limited to the four-divided photodiode 16a1, and may be any sensor that can detect the irradiation position with desired accuracy. For example, as shown in FIG. 3B, a sensor using a two-divided photodiode 16a2 may be used. By combining a slit provided obliquely with respect to the direction in which the diode of the two-divided photodiode 16a2 is divided, the position irradiated on the slit can be determined from the photodiode outputs De and Df on the X and Y axes. It can be calculated as displacement information. In addition, when the quadrant photodiode 16a1 is used, irradiation with the laser beam can be detected in a static state, but in this method, the timing is obtained by detecting the output of the two-segment photodiode 16a2 on the time axis. It can be used as a sensor and can be calculated from information obtained in a dynamic state in which main scanning with laser light is repeated while shifting in the Y-axis direction.

  Further, the position and timing can be detected more effectively by modulating the laser light and detecting the modulation information on the time axis as a change in the output of the photosensor 16a.

FIG. 4A is a side view showing a sensor installation position in the double-side exposure apparatus 100.
In the above description, in order to simplify the description, the photo sensor 16a is arranged at a position exceeding the substrate 1 (common irradiation position Ls). However, in the case of the double-side exposure apparatus 100, as described above, the half mirror is used. 15 and the sensor 16 is arranged on the side where the laser beam is incident on the substrate 1.
The half mirror 15 reflects a part of the laser beam La (or Lb) and guides it to the sensor 16. Similar to the photosensor 16a, the sensor 16 uses a photosensor 16a composed of a four-division photodiode 16a1, and detects the beam irradiation points of the laser beams La and Lb by the same method as described above.

Next, a method for adjusting the irradiation position (scanning range) of the second scanning light to the common irradiation position Ls detected above will be described.
FIG. 4B is a perspective view showing a state in which the first scanning light and the second scanning light are irradiated to the common irradiation position Ls. In addition to the first scanning light, in the second optical path, the second scanning is performed from the laser light Lc irradiating one end A point of the common irradiation position Ls to the laser light Ld irradiating the other end B point of the common irradiation position Ls. It shows how light is scanning.

In order to adjust the irradiation position of the second scanning light to the detected common irradiation position Ls, the beam irradiation point of the laser light Lc is applied to the beam irradiation point of the laser light La applied to one end A point of the common irradiation position Ls. And aligning the beam irradiation point of the laser beam Ld with the beam irradiation point of the laser beam Lb irradiated to the other end B point of the common irradiation position Ls.
As shown in FIG. 4A, a pair of half mirrors 25 and a pair of sensors 26 are arranged in the second optical path, as in the first optical path, and the laser beams Lc and Ld are transmitted in the same manner as in the first optical path. The beam irradiation point can be detected. Similar to the sensor 16, the sensor 26 uses a photosensor 16a including a four-divided photodiode 16a1.

The adjustment of the irradiation position of the second scanning light is performed by aligning the beam irradiation point detected by the sensor 26 with the beam irradiation point detected by the sensor 16, such as the mirror 22, the polygon mirror 23, and the fθ lens 24 that constitute the second optical path. Adjust.
Note that the coordinate system of the beam irradiation point detected by the sensor 26 and the beam irradiation point detected by the sensor 16 is corrected and calibrated in advance so as to be directly comparable. Further, the accuracy of fitting is performed within a necessary and sufficient allowable range.

By the above, the one-dimensional space of the specific range which can irradiate 1st scanning light and 2nd scanning light synchronizing can be shared as the common irradiation position Ls.
Here, by controlling the laser light emitted from each of the laser light sources 11 and 21 in synchronization with the control of the laser controller 50, it is possible to expose an image with extremely small deviation between the front and back of the substrate 1. . For example, when modulation is performed based on the same data, exposure can be performed on the front and back of the substrate 1 as the same image (an image that overlaps when viewed in plan).

  The incident angle of the first and second scanning lights with respect to the substrate 1 is not particularly limited. FIG. 5 is a side view showing the scanning light incident on the side surface of the exposed member. As shown in FIG. 5, the scanning light may be incident on the flat member to be exposed at a specific angle. . In this case, for example, in exposure for processing the surface layer 2 (for example, a resist or the like) that wraps around the side surface of the member to be exposed as shown in FIG. Can be exposed.

As described above, according to the exposure apparatus of the present embodiment, the following effects can be obtained.
Since exposure can be performed simultaneously with the first scanning light and the second scanning light, an exposure apparatus with higher throughput can be provided.
In addition, since the irradiation position of the second scanning light can be directly aligned with the irradiation position of the first scanning light, the alignment accuracy of each laser beam can be further increased. Specifically, for example, when irradiating from the front and back of a flat plate, if each side is independently aligned, an accumulated error (an error of a square sum of errors of each surface) occurs. In the case of the exposure apparatus according to the present embodiment, the range of the alignment error of the second scanning light with respect to the first scanning light can be suppressed.
Further, there is no need to provide a common alignment mark or a through hole for alignment on the front and back surfaces of the flat plate. Therefore, in the case of a flat plate, the application area to the product can be ensured to the maximum, so that the manufacturing efficiency can be increased.
Therefore, according to the exposure apparatus according to the present embodiment, by performing double-sided batch exposure, it is possible to provide an exposure apparatus with higher throughput, higher alignment accuracy in double-sided exposure, and higher use efficiency of the exposed material. Can do.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below. Here, the same components as those in the first embodiment are denoted by the same reference numerals, and redundant descriptions are omitted.

(Modification 1)
In the first embodiment, as shown in FIG. 1, laser light is scanned in the main scanning direction, and the substrate 1 as an exposed member is held by the holding unit 30 and moved in the sub-scanning direction to perform exposure as a surface. However, the present invention is not limited to this configuration. For example, the exposed member is irradiated as beam light without scanning with laser light, and the exposed member is not moved in a certain sub-scanning direction, but is set in a preset length in a preset direction. It may be configured to be moved. That is, a configuration having a function of flexibly moving in a preprogrammed direction may be used.

FIG. 6A is an explanatory view showing a portion to be exposed of the exposure apparatus according to the first modification.
FIG. 6A shows a state in which the object 3 as the member to be exposed is gripped by the gripping unit 40 and the laser beams L1, L2, and L3 are irradiated to the common irradiation position C on the surface of the object 3. Show.

  A half mirror 15 and a sensor 16 are provided on the optical axes of the laser beams L1, L2, and L3. The coordinate systems of the beam irradiation points detected by the sensors 16 are corrected and calibrated so that they can be directly compared in advance. The laser light L1, L2, and L3 are aligned with the common irradiation position C. ing.

FIG. 6B is a perspective view showing an articulated robot 200 as sub-scanning means in the present modification.
The gripping unit 40 is a hand unit of an articulated robot shown in FIG. 6B, moves the exposed part of the object 3 to be gripped to the common irradiation position C, and a desired exposure part passes through the common irradiation position C. The object 3 is moved as follows.

The exposure apparatus according to this modification can obtain the following effects.
Since the member to be exposed is arranged at the common irradiation position C and the articulated robot is used as the sub-scanning means for moving the member to be exposed for a preset length in a preset direction, An exposure apparatus capable of exposing a preset range can be easily provided. Also, by using an articulated robot as the sub-scanning means, the exposure range can be set more flexibly and simply.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 11, 21 ... Laser light source, 12, 22 ... Mirror, 13, 23 ... Polygon mirror, 14, 24 ... f (theta) lens, 15, 25 ... Half mirror, 16, 26 ... Sensor, 16a ... Photo sensor, 30 ... holding unit, 50 ... laser control unit, 100 ... double-sided exposure apparatus.

Claims (7)

An exposure apparatus comprising: a first optical path that scans and irradiates a first laser beam; and a second optical path that scans and irradiates a second laser beam from a direction different from the irradiation direction of the first optical path. And
A first sensor for detecting an end of an irradiation position of the first laser beam;
A second sensor for detecting an end of the irradiation position of the second laser beam,
After aligning the end of the irradiation position of the second laser light detected by the second sensor with the end of the irradiation position serving as a reference of the first laser light detected by the first sensor, the first An exposure apparatus for irradiating a member to be exposed with the laser beam and the second laser beam. The first optical path for scanning the first laser beam in a one-dimensional direction;
The second optical path for scanning the second laser light in a one-dimensional direction,
2. The exposure apparatus according to claim 1, wherein the irradiation position as a reference of the laser light in the first optical path is distributed along a one-dimensional space of the laser light in the second optical path. The first sensor is a pair of photosensors that detect irradiation positions at both ends of a one-dimensional space irradiated with laser light in the first optical path,
3. The exposure apparatus according to claim 2, wherein the second sensor is a pair of photosensors that detect irradiation positions at both ends of a one-dimensional space irradiated with laser light in the second optical path.   4. The exposure apparatus according to claim 2, wherein the scanning means for the first optical path and the second optical path includes a polygon mirror.   5. The apparatus according to claim 2, further comprising sub-scanning means for moving the exposed member in a direction intersecting with a one-dimensional space constituting an irradiation position serving as a reference of the first laser light. The exposure apparatus according to one item.   6. The exposure apparatus according to claim 1, wherein the first laser beam and the second laser beam are modulated by the same data and are irradiated substantially simultaneously.   The exposure apparatus according to claim 6, wherein the sub-scanning unit includes an articulated robot.

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