Method for manufacturing polishing carrier plate

Abstract

To provide a method for manufacturing a polishing carrier plate capable of suppressing distortion of a substrate after forming a plurality of through-holes by irradiating a laser beam.SOLUTION: Provided is a method for manufacturing a polishing carrier plate by irradiating a laser beam along a processing path 101 set on a circular metal substrate 10 to form a plurality of waste holes, including: a step of irradiating a laser beam from a start position set in a cutout area 100 to a start and end point set on a processing path 101; a step of irradiating a laser beam from the start and end point to a start and end point along the processing path 101 by making a full circle; and a step of cutting away from the start and end point toward the inside of the cutout area 100; wherein the start and end points are set at the position α where the processing path 101 intersects with a reference ray L, which is a ray extending radially from the center point O of the substrate 10 and has an angle θ between the center point O of the substrate 10 and a first ray L1 passing through the center point O1 of the cutout area 100 and is set to zero degree or a constant angle.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a polishing carrier plate.

Background Art

[0002] Generally, in a polishing apparatus for polishing the surface of a workpiece such as a semiconductor wafer, glass, crystal, or various mechanical parts, a carrier plate is used to hold the workpiece.

[0003] Here, to manufacture a carrier plate, first, a base material made of a thin metal plate such as stainless steel or titanium is cut out into a circular shape to form a disc-shaped substrate. Next, a laser beam is irradiated along a processing path set on the substrate to cut out a plurality of through holes such as carrier holes and waste holes. Then, after heat treatment, the surface of the substrate is lapped to complete it (see, for example, Patent Document 1 or Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, to cut out a through hole from a substrate, start and end points are set in advance on the processing path, and a laser beam is irradiated along the processing path from the start point and around once until it reaches the start point again. However, in the conventional method for manufacturing a polishing carrier plate, sufficient consideration has not been given to the setting of the positions of the start and end points. Therefore, it is difficult to suppress the distortion generated in the substrate by forming a plurality of through holes, and it has been necessary to remove the distortion generated in the substrate by long-time lapping.

[0006] The present invention has been made paying attention to the above problems, and an object thereof is to provide a method for manufacturing a polishing carrier plate capable of suppressing distortion of a substrate after forming a plurality of through holes by irradiating laser light.

Means for Solving the Problems

[0007] In order to achieve the above object, a method for manufacturing a polishing carrier plate according to the present invention irradiates laser light along a processing path set on a circular substrate made of metal, and cuts out the substrate to form a plurality of through holes. The method for manufacturing a polishing carrier plate includes a step of irradiating the laser light from a start position set within a cutting region surrounded by the processing path to a start / end point set on the processing path, a step of irradiating the laser light along the processing path from the start / end point and returning to the start / end point, and a step of irradiating the laser light from the start / end point toward the inside of the cutting region to release the cut. The start / end point is a radiation extending in the radial direction from the center point of the substrate, and is set at a position where an angle of an angle formed by a first radiation passing through the center point of the substrate and the center point of the cutting region and the processing path intersects, and the angle is set to zero degrees or a constant angle.

Effects of the Invention

[0008] In the method for manufacturing a polishing carrier plate according to the present invention, distortion of the substrate after forming a plurality of through holes by irradiating laser light can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

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Figure 11A

Figure 11B

Mode for Carrying Out the Invention

[0010] Hereinafter, a mode for carrying out a method for manufacturing a polishing carrier plate of the present invention will be described based on Example 1 shown in the drawings.

[0011] The polishing carrier plate (hereinafter referred to as "carrier plate 1") manufactured by the manufacturing method of Example 1 includes a circular substrate 10, a plurality of work holes 20 formed in the substrate 10, and a plurality of discard holes 30.

[0012] The substrate 10 is a thin plate member made of metal such as stainless steel or titanium. The substrate 10 has a circular shape in plan view. Further, a gear 10a is formed over the entire outer peripheral edge of the substrate 10.

[0013] The work hole 20 is a through hole formed by irradiating the substrate 10 with a laser beam and cutting out a part of the substrate 10. Inside the work hole 20, the work is placed during work polishing. The number, shape, and arrangement of the work holes 20 can be arbitrarily set. In the example shown in FIG. 1, three work holes 20 having the same size in plan view are evenly formed along the circumferential direction around the center point O of the substrate 10. When a plurality of work holes 20 are formed in the substrate 10, each work hole 20 may have a different shape or size. Further, the inner peripheral edge of the work hole 20 may be lined with plastic.

[0014] The waste hole 30 is a through hole formed by irradiating the substrate 10 with a laser beam and cutting out a part of the substrate 10. The waste hole 30 is a through hole other than the work hole 20 formed in the substrate 10, and is formed for discharging the slurry during work polishing and suppressing deformation of the substrate 10. The number, shape, and arrangement of the waste holes 30 can be arbitrarily set. In the example shown in FIG. 1, three waste holes 30 having the same size in plan view are evenly formed along the circumferential direction at positions that do not overlap with the work holes 20 around the center point O of the substrate 10. When a plurality of waste holes 30 are formed in the substrate 10, each waste hole 30 may have a different shape or size.

[0015] The manufacturing method of the carrier plate 1 of Example 1 is performed according to the procedure shown in the flowchart of FIG. 2.

[0016] That is, in step S1, a base material made of a thin metal plate to be processed on the carrier plate 1 is prepared, and the process proceeds to step S2. The material of the base material is arbitrarily selected, and is, for example, stainless steel or titanium.

[0017] In step S2, following the preparation of the base material in step S1, the substrate 10 is cut out from the base material, and the process proceeds to step S3. The cutting out of the substrate 10 is performed by irradiating a laser beam along an outer shape path set in advance on the base material.

[0018] In step S3, following the cutting out of the substrate 10 in step S2, a punching process of the work hole 20 is performed, and the process proceeds to step S4. In the punching process of the work hole 20, first, a machining path corresponding to the shape of the work hole 20, a starting position located inside the machining path, and a start / end point located on the machining path are set at a predetermined position of the substrate 10. Note that the positions of the starting position and the start / end point can be arbitrarily set according to the shape and arrangement of the work hole 20. Then, laser light is irradiated from the starting position to the start / end point, the substrate 10 is irradiated with laser light along the machining path from the start / end point until it returns to the start / end point, and after irradiating the laser light from the start / end point toward the inside of the machining path and then escaping, the work hole 20 is punched out from the substrate 10.

[0019] In step S4, following the punching process of the work hole 20 in step S3, a punching process of the waste hole 30 (through hole) is performed, and the process proceeds to step S5. Note that the punching process of the waste hole 30 will be described later using the flowchart shown in FIG. 3.

[0020] In step S5, following the punching process of the waste hole 30 in step S4, the substrate 10 in which all the through holes have been punched is heat-treated, and the process proceeds to step S6. Note that the heat treatment is, for example, annealing.

[0021] In step S6, following the heat treatment in step S5, after cooling the substrate 10, the front and back surfaces of the substrate 10 are each subjected to lapping, and the process proceeds to the end. Here, the lapping is performed until the distortion of the substrate 10 is removed and the front and back surfaces of the substrate 10 become flat respectively.

[0022] The punching process of the waste hole 30 in step S4 is performed according to the procedure shown in the flowchart of FIG. 3.

[0023] That is, in step S41, a machining path 101 and a start position 102 (see FIG. 4) corresponding to the shape of the discard hole 30 are set at a predetermined position on the substrate 10, and the process proceeds to step S42. In the first embodiment, as shown in FIG. 4, the machining path 101 is annular, and the cutout region 100 surrounded by the machining path 101 is circular in plan view. Further, the start position 102 is set at an arbitrary position within the cutout region 100 surrounded by the machining path 101. Note that the machining path 101 and the start position 102 are not physically attached to the substrate 10, but are set computationally based on the center point O of the substrate 10 or the like.

[0024] In step S42, following the setting of the machining path 101 and the start position 102 in step S41, a start / end point 103 (see FIG. 4) is set on the machining path 101, and the process proceeds to step S43. Here, as shown in FIG. 5, the start / end point 103 is set at a position α where a reference radiation line L, which is a radiation line extending radially from the center point O of the substrate 10, intersects the machining path 101. The reference radiation line L coincides with or is inclined at a certain angle with respect to a first radiation line L1 passing through the center point O of the substrate 10 and the center point O1 of the cutout region 100, and is a straight line in which the angle θ formed by the first radiation line L1 and the reference radiation line L is set to zero degrees or a certain angle.

[0025] That is, the angle θ formed by the first radiation line L1 and the reference radiation line L can be arbitrarily set. Therefore, for example, as shown in FIG. 6, the angle θ may be set to zero degrees, and the reference radiation line L may pass through the center point O of the substrate 10 and the center point O1 of the cutout region 100 and coincide with the first radiation line L1. In this case, the start / end point 103 is set at a position α where the reference radiation line L passing through the center point O of the substrate 10 and the center point O1 of the cutout region 100 intersects the machining path 101.

[0026] Further, as shown in FIG. 7, the angle of the angle θ may be set to an angle at which the reference radiation L becomes a tangent to the processing path 101. That is, the reference radiation L is a straight line that passes through the center point O1 of the cutout region 100 and is tangent to the processing path 101 at the position α where the straight line L2 orthogonal to the first radiation L1 intersects the processing path 101. In this case, the start and end point 103 is set at the position α where the reference radiation L that passes through the center point O of the substrate 10 and is tangent to the processing path 101 and the processing path 101 are in contact with each other.

[0027] Furthermore, as shown in FIG. 8, a plurality of discard holes 30 may be divided in a plurality of arbitrarily set areas A on the substrate 10, and the angle of the angle θ may be made different for each area A.

[0028] And, as shown in FIGS. 5 and 6, when there are two positions α where the reference radiation L and the processing path 101 intersect, either one of the two positions α is set as the start and end point 103.

[0029] In step S43, following the setting of the start and end point 103 in step S42, as indicated by the broken-line arrow in FIG. 4, the substrate 10 is irradiated with laser light from the start position 102 to the start and end point 103, and the process proceeds to step S44. Here, the path of irradiating the laser light from the start position 102 to the start and end point 103 can be arbitrarily set. Also, the moving speed (cutting speed) of the laser light can be arbitrarily set, and it may be a constant speed or may be varied depending on the position.

[0030] In step S44, following the irradiation of the laser light from the start position 102 to the start and end point 103 in step S43, as indicated by the solid-line arrow in FIG. 4, the substrate 10 is irradiated with laser light from the start and end point 103 along the processing path 101 for one round until it reaches the start and end point 103, and the process proceeds to step S45. Here, the moving speed (cutting speed) of the laser light can be arbitrarily set, and it may be a constant speed or may be varied depending on the position.

[0031] In step S45, following the irradiation of the laser beam from the start / end point 103 to the start / end point 103 in step S44, as indicated by the dashed-dotted arrow in FIG. 4, the laser beam is irradiated from the start / end point 103 toward the inside of the cutout region 100 to cut away and proceed to the end. Here, the moving speed (cutting speed) of the laser beam can be arbitrarily set, and it may be a constant speed or may vary depending on the position. Note that "cutting away" means stopping the irradiation of the laser beam at an appropriate position inside the cutout region 100.

[0032] Hereinafter, the operation of the manufacturing method of the carrier plate 1 of Example 1 will be described.

[0033] In the manufacturing method of the carrier plate 1 of Example 1, when cutting out the discard holes 30 (through holes) from the substrate 10, the start / end point 103 set on the processing path 101 is a radiation extending radially from the center point O of the substrate 10, and is set at a position α where the reference radiation L, at which the angle θ formed by the first radiation L1 passing through the center point O of the substrate 10 and the center point O1 of the cutout region 100 is set to zero degrees or a constant angle, intersects with the processing path 101.

[0034] That is, in the manufacturing method of the carrier plate 1 of Example 1, regardless of the arrangement of the plurality of discard holes 30, the plurality of start / end points 103 are set to be radially dispersed around the center point O of the substrate 10. Therefore, when forming the plurality of discard holes 30 by laser processing, each discard hole 30 is cut out from a radial position with respect to the center point O of the substrate 10. Thereby, the manufacturing method of Example 1 can regularly distribute the positions where the heat by the laser beam stays when cutting out the discard holes 30 from the substrate 10 by irradiating the laser beam along the processing path 101. And it becomes possible to reduce or regularly distribute the residual stress in the substrate 10.

[0035] As a result, the manufacturing method of Example 1 can suppress the distortion and warping generated in the substrate 10 by forming the discard hole 30, and improve the flatness of the substrate 10. And the manufacturing method of Example 1 can reduce the distortion of the substrate 10 and shorten the lapping processing time for flattening the substrate 10 compared with the case where the starting and ending point 103 is set at the right end point of the processing path 101 in a plan view in a circular cutout region 100 that becomes the discard hole 30, such as the carrier plate 1X shown in FIG. 9.

[0036] The table shown in FIG. 10 is a table showing the ratios of the lapping areas of the front and back surfaces of the substrate 10 in the first to third samples when lapping processing is performed for a predetermined same time (about 30 minutes) after forming the discard hole 30 and then performing heat treatment on the substrate 10. The "lapping area" is the area of the portion where the distortion of the substrate 10 is almost removed by lapping processing and the variation in flatness becomes within a predetermined range.

[0037] Here, when the substrate 10 is lapped, a change occurs in the flatness (undulation) of the portion where the distortion of the substrate 10 is removed. And the smaller the distortion of the substrate 10 is when there is no variation in flatness on the surface of the substrate 10, which means that the substrate 10 has been lapped evenly. That is, in FIG. 10, the larger the numerical value is, the wider the lapping area is, which means that it has been polished appropriately.

[0038] The first sample is a carrier plate 1X in which the cutout region 100 that becomes the discard hole 30 is circular in plan view, and in all the cutout regions 100, the start / end point 103 is set at the right end point of the processing path 101 in plan view (see Fig. 9). Also, the second sample is a carrier plate 1A in which the cutout region 100 that becomes the discard hole 30 is circular in plan view, and in all the cutout regions 100, the reference radiation L that coincides with the first radiation L1 and passes through the center point O of the substrate 10 and the center point O1 of the cutout region 100 intersects with the processing path 101, and the start / end point 103 is set at the position α closer to the center point O of the substrate 10 (see Fig. 11A). Further, the third sample is a carrier plate 1B in which the cutout region 100 that becomes the discard hole 30 is circular in plan view, and in all the cutout regions 100, the reference radiation L that coincides with the first radiation L1 and passes through the center point O of the substrate 10 and the center point O1 of the cutout region 100 intersects with the processing path 101, and the start / end point 103 is set at the position α farther from the center point O of the substrate 10 (see Fig. 11B).

[0039] As is clear from the table in Fig. 10, in the first sample, the ratio of the lapping area is about 35% on both the front and back surfaces. Therefore, it was found that in the first sample, the variation in flatness is large and the substrate cannot be evenly lapped within a predetermined lapping processing time (30 minutes).

[0040] In contrast, in the second sample, the ratio of the lapping area is 70% or more, and in the third sample, the ratio of the lapping area is about 60%. Therefore, it was shown that in the second and third samples, the variation in the flatness of the substrate 10 after processing the discard hole 30 can be suppressed, and even within a predetermined lapping processing time (30 minutes), the surface of the substrate 10 can be almost evenly lapped.

[0041] Thereby, when the start / end point 103 is set at the position α where the reference radiation L passing through the center point O of the substrate 10 and the center point O1 of the cutout region 100 intersects with the processing path 101, that is, it was found that the method for manufacturing the polishing carrier plate of Example 1 can suppress the distortion and warping of the substrate 10 after forming the discard hole 30 by irradiating laser light.

[0042] In the second sample and the third sample, the cutout region 100 is circular in plan view, and the reference radiation line L determined when setting the start and end points 103 passes through the center point O of the substrate 10 and the center point O1 of the cutout region 100.

[0043] That is, by setting the start and end points 103 at the position where the reference radiation line L passing through the center point O of the substrate 10 and the center point O1 of the cutout region 100 intersects with the processing path 101, as shown in FIGS. 11A and 11B, the position of the start and end points 103 can be easily radially dispersed around the center point O of the substrate 10 in plan view. Thereby, the retention of heat when irradiating the laser light can be regularly distributed, and the distortion of the substrate 10 can be suppressed.

[0044] Also, for the cutout region 100, the angle of the angle θ formed by the reference radiation line L and the first radiation line L1 may be adjusted, and as shown in FIG. 7, the reference radiation line L may be set at an angle that becomes a tangent to the processing path 101 in plan view. In other words, the reference radiation line L may be in contact with the processing path 101 at the position where the straight line L2 passing through the center point O1 of the cutout region 100 and orthogonal to the first radiation line L1 intersects with the processing path 101. That is, the start and end points 103 may be set at the position where the straight line L2 passing through the center point O1 of the cutout region 100 and orthogonal to the first radiation line L1 intersects with the processing path 101.

[0045] Even in this case, the start and end points 103 can be easily radially dispersed around the center point O of the substrate 10 in plan view, and the retention of heat when irradiating the laser light can be regularly distributed. And the distortion of the substrate 10 can be suppressed.

[0046] As described above, the method for manufacturing the polishing carrier plate of the present invention has been described based on Example 1. However, the specific configuration is not limited to this example, and design changes, additions, etc. are allowed as long as they do not depart from the gist of the invention according to each claim.

[0047] In the manufacturing method of Example 1, an example was shown in which the through-hole formed in the substrate 10 is the waste hole 30. However, the through-hole cut out by irradiating the substrate 10 with laser light is not limited to the waste hole 30, and may be the work hole 20. Further, it may be a through-hole other than the work hole 20 or the waste hole 30.

[0048] Also, in the manufacturing method of Example 1, an example was shown in which the waste hole 30, which is a through-hole, is circular in plan view. However, the shape of the through-hole (waste hole 30) is not limited to circular, and may be, for example, elliptical, hexagonal, pentagonal, rectangular, square or other rectangular shapes, slit-shaped long hole shapes, etc. in plan view. Even if the shape of the through-hole is other than circular in plan view, it is possible to set the first radiation and the reference radiation by setting the center point O1 of the cut-out region 100.

[0049] Also, in the example shown in FIG. 7, an example was shown in which the cut-out region 100 that becomes the waste hole 30 is circular in plan view, and the reference radiation L is in contact with the processing path 101 at the position where the straight line L2 intersects the processing path 101. However, as described above, the shape of the waste hole 30 (through-hole) is not limited to circular. Therefore, the reference radiation L may intersect the processing path 101 at the position where the straight line L2 intersects the processing path 101.

Explanation of symbols

[0050] 1 Carrier plate for polishing 10 Substrate 20 Work hole (through-hole) 30 Waste hole (through-hole)

Claims

1. A method for manufacturing a polishing carrier plate, which irradiates a laser beam along a processing path set on a circular substrate made of metal, cuts out the substrate, and forms a plurality of through holes, comprising: a step of irradiating the laser beam from a starting position set within a cutting-out region surrounded by the processing path to a start / end point set on the processing path; a step of irradiating the laser beam along the processing path from the start / end point and making one full turn until reaching the start / end point; a step of irradiating the laser beam from the start / end point toward the inside of the cutting-out region to allow escape; and having the start / end point is a radiation extending radially from the center point of the substrate, and is set at a position where the angle of the angle formed by a first radiation passing through the center point of the substrate and the center point of the cutting-out region and the reference radiation is set to zero degrees or a constant angle, and the processing path intersect; A method for manufacturing a polishing carrier plate, characterized by the above.

2. In the method for manufacturing a polishing carrier plate according to Claim 1, the reference radiation passes through the center point of the substrate and the center point of the cutting-out region and coincides with the first radiation A method for manufacturing a polishing carrier plate, characterized by the above.

3. In the method for manufacturing a polishing carrier plate according to Claim 1, the reference radiation passes through the center point of the cutting-out region, and at a position where a straight line perpendicular to the first radiation intersects the processing path, it intersects or touches the processing path A method for manufacturing a polishing carrier plate, characterized by the above.

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