Dust collection equipment and laser processing equipment

Abstract

In a laser processing apparatus equipped with a dust collection device, an airflow capable of effectively removing debris is created within the dust collection chamber. [Solution] The laser processing apparatus 100 is equipped with a dust collector 80 between the projection optical system 30 and the substrate W (processing stage 50). The dust collector 80 is equipped with a dust collection chamber 81, and insertion ports for the air supply nozzle 60 and exhaust duct 70 are formed as a first vent 82 and a second vent 84 at opposing positions on the housing 81C. A space area GA into which outside air can be drawn in during processing is provided between the first vent 82 and the air supply nozzle 60, and a space area GB into which outside air can be drawn in during processing is provided between the second vent 84 and the exhaust duct 70.

Description

Technical Field

[0001] The present invention relates to a laser processing apparatus, and particularly to a dust collecting apparatus for removing dust (hereinafter referred to as debris) scattered during laser processing.

Background Art

[0002] In a laser processing apparatus, while scanning a laser beam with respect to a mask, light transmitted through the mask pattern is irradiated onto a workpiece such as a substrate, and processing such as cutting or removal is performed. By irradiating a workpiece with a laser beam having a high energy density, the surface portion is melted, evaporated, or explosively released and removed in the form of atoms or molecules, and a processing pattern is formed.

[0003] The workpiece that has evaporated or been released becomes debris and scatters around. To remove this, a dust collecting apparatus is provided. For example, a dust collecting chamber is provided below the projection optical system, and debris is discharged through an exhaust port (see Patent Document 1).

[0004] Also, in order to prevent debris from adhering to the surface of the workpiece and the projection optical system when the debris scatters, a configuration for collecting dust near the surface of the workpiece is known. In this case, a gas such as an inert gas is blown out near the surface of the workpiece by a nozzle, and a duct is provided on the opposite side of the nozzle for discharging (see Patent Document 2).

[0005] Also, a dust-proof cover is arranged so as to cover the nozzle and the duct (see Patent Document 3).

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0007] Air intake ports and exhaust ports, such as air supply nozzles and exhaust ducts, are installed so as not to overlap with the scanning range of the laser beam. Therefore, if a dust collection chamber is installed, vortices or turbulence in the airflow will occur within the chamber, affecting the debris flow, causing it to remain inside the chamber and adhere to and accumulate on the walls of the chamber, the surface of the workpiece, and the lenses of the projection optical system. The adhesion and accumulation of debris will affect the machining accuracy.

[0008] Therefore, in laser processing equipment equipped with a dust collection device, it is necessary to create an airflow within the dust collection chamber that can effectively remove debris. [Means for solving the problem]

[0009] A laser processing apparatus according to one aspect of the present invention includes a scanning mechanism that scans a laser beam across a mask, a projection optical system that projects the laser beam that has passed through the mask onto a workpiece mounted on a processing stage, an air intake port connected to a gas supply device, an exhaust port connected to an exhaust device, and a dust collection chamber provided between the projection optical system and the workpiece stage, with first and second ventilation ports in the housing into which the air intake port and exhaust port are inserted, respectively.

[0010] Here, the first and second vents are defined as openings provided on the side of the dust collection chamber surrounding the processing area, and are partially formed on the side. Therefore, openings that are not part of the dust collection chamber side and are simply open ends are not included.

[0011] The air intake and exhaust ports have the functions of sending gas to the outside and drawing gas in, respectively, and their structure and shape are arbitrary. For example, they can be composed of an air intake nozzle and an exhaust duct. The air intake nozzle can be positioned so that its tip is close to the boundary of the laser beam's scanning range. The duct can be positioned so that the edge of its tip is close to the boundary of the laser beam's scanning range and follows the vertical direction.

[0012] In this invention, gaps are provided between the first vent and the air supply port, and between the second vent and the exhaust port, so that outside air can enter the dust collection chamber through the first and second vents during processing.

[0013] Here, "gap" refers to a spatial gap that is intentionally created, and the sizes of the first and second openings, and the air intake and exhaust ports (the parts corresponding to the positions of the first and second openings) are determined so that a predetermined distance is maintained between the outer surfaces of the air intake and exhaust ports and the first and second openings, and so that they are arranged in a relative position.

[0014] Therefore, a state in which unintended spatial gaps are formed is different from the "gap" as used here. For example, even if the air intake and exhaust ports are fitted into the dust collection chamber so as to be in contact with the first and second openings around their entire outer surface, tiny gaps (air pockets) that allow gas to unintentionally flow into the dust collection chamber due to the lack of close contact are not included in the "gap" as used here. At a minimum, a spatial region in which gas flow occurs within the dust collection chamber is provided between the air intake port and the first opening, and between the exhaust port and the second opening.

[0015] The shape and size of the gap space can vary, and the first and second openings can be determined according to the shape and size of the air intake and exhaust ports. Alternatively, the sizes of the air intake and exhaust ports can be determined so that a gap is created between the first and second openings of predetermined sizes.

[0016] For example, the spatial area between the air intake and the first vent (the first spatial area) can be made larger than the spatial area between the exhaust and the second vent (the second spatial area). Also, if the second vent is rectangular, the upper area between the exhaust and the upper edge of the second spatial area can be made larger than the lower area between the exhaust and the lower edge.

[0017] The second space region between the second vent and the exhaust port can have an arbitrarily configured spatial shape. For example, if the second vent is rectangular, in the second space region, the upper region between the exhaust port and the upper edge can be made larger than the lower region between the exhaust port and the lower edge.

[0018] The air supply port and the exhaust port may be supported by the dust collection device, or may be fixed to the support body that supports the projection optical system. For example, the air supply port and the exhaust port can be supported by a support member fixed to the support body.

[0019] During processing, the suction volume of the exhaust device can be made larger than the air supply volume of the gas supply device. Also, an outside air inlet for introducing outside air into the dust collection chamber can be provided between the projection optical system and the dust collection chamber.

[0020] A dust collection device according to another aspect of the present invention is a dust collection device for a laser processing apparatus including a scanning mechanism for scanning a laser beam onto a mask and a projection optical system for projecting the laser beam transmitted through the mask onto a workpiece mounted on a processing stage. The dust collection device includes a dust collection chamber provided in a housing with an air supply port connected to a gas supply device, an exhaust port connected to an exhaust device, and first and second vents into which the air supply port and the exhaust port are respectively inserted, provided between the projection optical system and the processing stage. During processing, gaps are provided between the first vent and the air supply port and between the second vent and the exhaust port so that outside air enters the dust collection chamber through the first and second vents.

Advantages of the Invention

[0021] According to the present invention, in a laser processing apparatus provided with a dust collection device, an airflow capable of effectively removing debris can be created in the dust collection chamber.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic configuration diagram of the laser processing apparatus according to the present embodiment. [Figure 2] It is a schematic cross-sectional view near the dust collection device of the laser processing apparatus. [Figure 3] It is a side view seen from the exhaust duct side of the dust collection device. [Figure 4] It is a diagram showing the airflow generated in the dust collection chamber during processing.

Embodiments for Carrying Out the Invention

[0023] FIG. 1 is a schematic configuration diagram of the laser processing apparatus according to the present embodiment.

[0024] The laser processing apparatus 100 is a processing apparatus capable of forming a pattern on a substrate (workpiece) W by ablation processing, and includes a light source device 10 and a device main body 12. The light source device 10 is installed on the floor independently of the device main body 12.

[0025] The light source device 10 is a laser that oscillates laser light with a high energy density. Here, it is configured as an excimer laser that pulse-irradiates KrF excimer laser light with a wavelength of 248 nm. The laser light emitted from the light source device 10 is sent to the device main body 12 through a beam transmission system not shown.

[0026] The device main body 12 includes an illumination optical unit 20, a scanning mechanism (not shown), a projection optical system 30, a mask stage 40, and a processing stage 50, and is supported by a support (not shown here) of the device main body 12. The support having a frame structure with four legs that are equally spaced from each other and extend vertically downward supports the illumination optical unit 20, the scanning mechanism, the projection optical system 30, the mask stage 40, and the processing stage 50. The mask M and the substrate W are mounted on the mask stage 40 and the processing stage 50, respectively.

[0027] The illumination optical unit 20 has a line beam forming optical system (not shown) including a cylindrical lens or the like, and shapes the beam luminous flux of the laser light incident along the main scanning direction (X direction) into a line-shaped beam. The line-shaped laser beam LB is guided to the mask M through a mirror not shown.

[0028] The illumination optical unit 20 moves back and forth along the main scanning direction (X direction) as the scanning mechanism moves. As the illumination optical unit 20 moves, a linear laser beam LB along the sub-scanning direction (Y direction) moves relative to the mask M and the projection optical system 30, scanning the mask M and substrate W fixed to the mask stage 40 and processing stage 50, respectively.

[0029] The mask stage 40 holds the mask M and can position the mask M by moving and rotating in the X-Y direction. The projection optical system 30 is an optical system with focal points on the surface of the mask M and the surface of the substrate W, and projects light transmitted through the mask M onto the substrate W. Here, the projection optical system 30 is configured as a reduction projection optical system (for example, with a magnification of 1 / 4).

[0030] The processing stage 50 has a chuck function and fixes the substrate W by vacuum suction or the like. The processing stage 50 also positions the substrate W relative to the mask M by moving in the X-Y direction and rotating on the XY plane. Furthermore, it is capable of step-by-step movement along the XY direction to enable ablation processing over the entire substrate W.

[0031] In this case, the substrate W is a resin substrate, with a copper wiring layer formed on a base material such as epoxy resin, and an insulating layer formed on top of that. By irradiating the substrate W with high-energy-density excimer laser light from the light source device 10, ablation occurs, and a pattern corresponding to the mask pattern (hereinafter referred to as the processed pattern) is formed.

[0032] The processing patterns that can be formed include through-vias, non-through-vias, trenches for wiring patterns, and cavities for semiconductor device mounting. After the processing patterns are formed on the substrate W by ablation processing, a conductor such as copper is filled into the substrate.

[0033] The laser processing apparatus 100 includes a controller (not shown) that controls the operation of the ablation process. When an operator performs an operation to perform the ablation process, the controller drives and controls the light source device 10 and the scanning mechanism to scan the linear laser beam LB in the main scanning direction (X direction). The controller also controls the movement of the mask stage 40 and the processing stage 50.

[0034] Furthermore, the laser processing apparatus 100 is equipped with a dust collector 80 to remove dust (hereinafter referred to as "debris") generated and scattered by the ablation process. The dust collector will be described below.

[0035] Figure 2 is a schematic cross-sectional view of the area around the dust collector 80 of the laser processing apparatus 100. Figure 3 is a side view of the dust collector 80 as seen from the exhaust duct side.

[0036] The dust collector 80 includes a cylindrical dust collection chamber 81 positioned between the projection optical system 30 and the processing stage 50, with a frame-shaped holding portion 88 formed on top of it. The holding portion 88 is fixed to the barrel base portion 30S of the projection optical system 30. The bottom surface 81B of the dust collection chamber 81 is close to the surface of the substrate W mounted on the processing stage 50.

[0037] As described above, the projection optical system 30 is supported by a support 15, along with a scanning mechanism that supports the illumination optical unit 20 and a mask stage 40. The dust collection chamber 81 is arranged coaxially with respect to the projection optical system 30, with the optical axis E of the projection optical system 30 as its center. An outside air inlet 90 is formed in a holding portion 88 that is formed between the barrel base portion 30S of the projection optical system 30 and the dust collection chamber 81.

[0038] The dust collector 80 is equipped with an air supply nozzle (air inlet) 60 and an exhaust duct (exhaust port) 70. Both the air supply nozzle 60 and the exhaust duct 70 are rectangular in shape with their longitudinal direction being horizontal, and are inserted into insertion ports 82 and 84, respectively, provided in the housing 81C of the dust collection chamber 81. Hereinafter, insertion port 82 will be referred to as the first vent, and insertion port 84 as the second vent.

[0039] The first vent 82 and the second vent 84 are formed in opposing positions in the dust collection chamber 81, with the air supply nozzle (air inlet) 60 and exhaust duct 70 facing each other. Here, the scanning direction of the linear laser beam LB corresponds to the direction perpendicular to the plane of the paper.

[0040] The air supply nozzle 60 is connected to the gas supply device 110 and ejects the gas supplied from the gas supply device 110 from its tip 60T. The gas that can be supplied includes, for example, an inert gas such as helium, or nitrogen gas.

[0041] The exhaust duct 70 is connected to an exhaust device (such as an exhaust pump) that acts as a negative pressure source and draws in gas from inside the dust collection chamber 81. The gas supply device 110 and the exhaust device 120 are controlled by a controller. Here, the gas supply device 110 and the exhaust device 120 operate so that the amount of suction during processing is greater than the amount of air supplied.

[0042] The air supply nozzle 60 extends downward from the first vent 82, inclined so that its tip 60T is close to the surface of the substrate W. The exhaust duct 70 is similarly inclined downward. On the other hand, the tip 60T of the air supply nozzle 60 and the tip 70T of the exhaust duct 70 are positioned so as to be outside the scanning range SR of the line-shaped laser beam LB, that is, the processing space S for ablation.

[0043] Specifically, the tip 60T of the air supply nozzle 60 is located near the bottom surface 81B of the dust collection chamber 81, which is close to the surface of the substrate W. The tip 70T of the exhaust duct 70 has a larger diameter than the tip 60T of the air supply nozzle 60, and its edge is aligned in the vertical direction of the device. In addition, the lower end of the tip 70T of the exhaust duct 70 is located near the bottom surface 81B of the dust collection chamber 81.

[0044] The section T of the scanning range SR follows the size of the mask M (e.g., 70 mm x 70 mm). A cylindrical optical component 32 made of transparent glass or the like is installed in the holding section 88 of the dust collection chamber 81, aligned with the scanning range SR.

[0045] The size of the first vent 82 into which the air supply nozzle 60 is inserted is determined such that a spatial region GA is formed around the air supply nozzle 60 through which outside air flows. There is a spatial gap between the air supply nozzle 60 and the first vent 82; that is, they are not in contact with each other, and are supported and positioned by a support member 62 fixed to the support body 15.

[0046] The second vent 84 into which the exhaust duct 70 is inserted also has a size that creates a space GB around the exhaust duct 70 through which outside air flows. There is also a gap between the exhaust duct 70 and the second vent 84, which is supported and positioned by a support member 72 fixed to the support body 15.

[0047] As described above, the air supply nozzle 60 and exhaust duct 70 are formed in a rectangular shape, and their size and the position of the tip 60T of the air supply nozzle 60 and the tip 70T of the exhaust duct 70 are determined according to the scanning range SR. The first vent 82 and the second vent 84 are formed in positions facing the dust collection chamber 81, according to the shape and arrangement of the air supply nozzle 60 and the exhaust duct 70.

[0048] The second vent 84 is set to the same size as the first vent 82. On the other hand, the nozzle diameter of the air supply nozzle 60 is smaller than the duct diameter of the exhaust duct 70. Therefore, the spatial region GA formed around the air supply nozzle 60 is larger than the spatial region GB formed around the exhaust duct 70. Note that if the diameters of the air supply nozzle 60 and the exhaust duct 70 are the same, the size of the first vent 82 may be made larger than the size of the second vent 84.

[0049] In spatial region GB, the spatial region GB1 between the exhaust duct 70 and the upper edge 84T of the second vent 84 (upper region) is larger than the spatial region GB2 between it and the lower edge 84B (lower region). On the other hand, at the first vent 82 of the air supply nozzle 60, the spatial region GA2 between the air supply nozzle 60 and the lower edge 82B (lower region) is larger than the spatial region GA1 between it and the upper edge 82T (upper region).

[0050] Figure 4 shows the airflow generated inside the dust collection chamber 81 during processing.

[0051] During processing, air is supplied from the gas supply device 110, and gas is ejected from the air supply nozzle 60 toward the surface of the substrate W. Meanwhile, the exhaust device 120 sucks the gas in the dust collection chamber 81 through the exhaust duct 70. As a result, an airflow is generated in the dust collection chamber 81. As described above, the amount of air sucked during processing is greater than the amount of air supplied.

[0052] The gas ejected from the air supply nozzle 60 flows through the vicinity of the surface of the substrate W into the exhaust duct 70. As a result, debris generated during processing is drawn out through the exhaust duct 70 by the airflow. In addition, the inflow of outside air from the outside air inlet 90 creates a downward flow of gas from the holding unit 88 towards the substrate W within the scanning range SR of the dust collection chamber 81.

[0053] Furthermore, in this embodiment, outside air flows into the dust collection chamber 81 through the first vent 82 and the second vent 84. As the outside air flows near the surface of the substrate W through the air supply nozzle 60, the outside air flows into the exhaust duct 70 accompanied by the gas ejected from the air supply nozzle 60. On the other hand, on the second vent 84 side of the dust collection chamber 81, outside air also flows into the dust collection chamber 81 through the exhaust duct 70.

[0054] Because the spatial region GA between the air supply nozzle 60 and the first vent 82 is wider than the spatial region GB between the exhaust duct 70 and the second vent 84, high-flow outside air flows into the dust collection chamber 81, creating a stable gas flow that proceeds to the exhaust duct 70. In particular, because the spatial region GA2 on the lower edge 82B side of the first vent 82 is relatively large, it is possible to reliably create a flow of outside air along the surface of the substrate W.

[0055] Furthermore, because the spatial region GB between the exhaust duct 70 and the second vent 84 is smaller than the spatial region GA, when outside air flows into the dust collection chamber 81 through the perimeter of the exhaust duct 70, it is possible to suppress a large amount of outside air from flowing forcefully into the processing space S, thereby preventing the generation of vortices and airflow turbulence near the tip 70T of the exhaust duct 70.

[0056] In particular, the space GB2 between the second vent 84 and the upper edge 84T is relatively large. Therefore, the outside air flowing in from the outside air inlet 90 and descending towards the substrate W is suppressed from convection near the second vent 84 side of the housing 81C, and is allowed to be drawn directly into the exhaust duct 70.

[0057] Regarding the exhaust duct 70, the size of its tip 70T is relatively large in order to quickly suck out debris generated during processing. In addition, the edge of the tip 70T is aligned vertically so that it avoids the scanning range SR. This allows for effective sucking out of debris generated near the surface of the substrate W.

[0058] While the exhaust device 120 is operating, its vibrations are transmitted to the exhaust duct 70. However, since the exhaust duct 70 is not fixed to the dust collection chamber 81, the vibrations are not transmitted to the dust collection chamber 81. As a result, vibrations are not transmitted to the projection optical system 30 above the dust collection chamber 81, thus preventing a decrease in machining accuracy.

[0059] As described above, the laser processing apparatus 100 of this embodiment is equipped with a dust collector 80 between the projection optical system 30 and the substrate W (processing stage 50). The dust collector 80 is equipped with a dust collection chamber 81, and insertion ports for the air supply nozzle 60 and exhaust duct 70 are formed as a first vent 82 and a second vent 84 at opposing positions on the housing 81C. A space region GA is provided between the first vent 82 and the air supply nozzle 60, allowing outside air to be drawn in during processing, and a space region GB is provided between the second vent 84 and the exhaust duct 70, allowing outside air to be drawn in during processing. [Explanation of Symbols]

[0060] 30 Projection optical system 60 Air supply nozzle (air inlet) 70 Exhaust duct (exhaust port) 80 Dust collector 81 Dust collection room 82 First vent 84 Second vent 100 Laser Processing Equipment

Claims

1. A scanning mechanism that scans a laser beam across a mask, A projection optical system that projects the laser beam that has passed through the mask onto a workpiece mounted on a processing stage, An air intake port connected to the gas supply device, The exhaust port connected to the exhaust system, The system includes a dust collection chamber provided between the projection optical system and the workpiece stage, with first and second ventilation openings in the housing into which the air intake and exhaust ports are respectively inserted, A laser processing apparatus characterized in that, during processing, gaps are provided between the first vent and the air supply port, and between the second vent and the exhaust port, respectively, so that outside air enters the dust collection chamber through the first and second vents.

2. The laser processing apparatus according to claim 1, characterized in that the first spatial region between the air intake port and the first vent is larger than the second spatial region between the exhaust port and the second vent.

3. The second ventilation opening is rectangular in shape. The laser processing apparatus according to claim 2, characterized in that, in the second spatial region, the upper region between the exhaust port and the upper edge is larger than the lower region between the exhaust port and the lower edge.

4. The projected optical system further comprises a support for the projection optical system, The laser processing apparatus according to claim 1, characterized in that the air intake port and the exhaust port are supported by a support member fixed to the support body.

5. The aforementioned air intake is a nozzle, The laser processing apparatus according to claim 1, characterized in that the nozzle is arranged such that its tip is close to the boundary of the scanning range of the laser beam.

6. The aforementioned exhaust port is a duct, The laser processing apparatus according to claim 1, characterized in that the edge of the tip of the duct is close to the boundary of the scanning range of the laser beam and is aligned in the vertical direction.

7. The laser processing apparatus according to claim 1, characterized in that, during processing, the amount of suction from the exhaust device is greater than the amount of air supplied from the gas supply device.

8. The laser processing apparatus according to any one of claims 1 to 7, characterized in that an outside air inlet for introducing outside air into the dust collection chamber is provided between the projection optical system and the dust collection chamber.

9. A dust collection device for a laser processing apparatus, comprising a scanning mechanism for scanning a laser beam across a mask, and a projection optical system for projecting the laser beam that has passed through the mask onto a workpiece mounted on a processing stage, An air intake port connected to the gas supply device, The exhaust port connected to the exhaust system, The system includes a dust collection chamber provided between the projection optical system and the workpiece stage, with first and second ventilation openings in the housing into which the air intake and exhaust ports are respectively inserted, A dust collection device characterized in that, during processing, gaps are provided between the first vent and the air supply port, and between the second vent and the exhaust port, respectively, so that outside air enters the dust collection chamber through the first and second vents.

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