MACHINING MACHINE AND METHOD FOR OPERATING A MACHINING MACHINE

Abstract

A machining machine includes an annular bottom working disk and a top counter bearing element. The bottom working disk and top counter bearing element are driven to rotate relative to each other. A working gap is defined between the bottom working disk and the top counter bearing to machine flat work pieces on at least one side. A means for generating a local deformation of the bottom working disk are also provided.

Claims

1. A machining machine comprising: a bottom working disk and a top counter bearing element, wherein the bottom working disk and top counter bearing element are configured to rotate relative to each other; a working gap defined between the bottom working disk and the top counter bearing element, the working gap configured to allow machining flat work pieces on at least one side; and a means for generating a local deformation of the bottom working disk.

2. The machining machine according to claim 1, further comprising a control apparatus configured to actuate the means for generating the local deformation of the bottom working disk.

3. The machining machine according to claim 1, wherein the top counter bearing element is a top working disk, and wherein the bottom working disk and the top working disk are arranged coaxially with respect to each other and are configured to rotate relative to each other, the top working disk and the bottom working disk define the working gap that is configured to machine at least one side of flat work pieces.

4. The machining machine according to claim 1, wherein the means for generating the local deformation of the bottom working disk are hydraulic means, pneumatic means, or mechanical means.

5. The machining machine according to claim 3, further comprising: a bottom support disk coupled to the bottom working disk; and an annular volume of pressure formed between the bottom support disk and the bottom working disk, the annular volume of pressure being configured to couple to a fluid supply, wherein the fluid supply is configured to be controlled so that pressure builds in the annular volume of pressure producing a predetermined local deformation of the bottom working disk.

6. The machining machine according to claim 5, wherein the bottom working disk is only coupled to the bottom support disk in a region of its outer edge and in a region of its inner edge.

7. The machining machine according to claim 1, further comprising a distance measuring apparatus configured to determine a thickness of the working gap or a deformation of the bottom working disk.

8. The machining machine according to claim 7, wherein the distance measuring apparatus includes at least one distance measuring sensor configured to measure a distance between the bottom working disk and a bottom support disk holding the bottom working disk at one or more points in the working gap.

9. The machining machine according to claim 7, wherein the distance measuring apparatus comprises at least two distance measuring sensors configured to measure a distance between the bottom working disk and the top counter bearing element at two or more points in the working gap.

10. The machining machine according to claim 8, further comprising a control apparatus configured to actuate the means for generating the local deformation in the bottom working disk in response to the measurements received from the distance measuring apparatus to create a predetermined local deformation in the bottom working disk.

11. The machining machine according to claim 10, wherein a means are also provided to generate a global deformation in the top counter bearing element.

12. The machining machine according to claim 11, wherein the control apparatus is configured to actuate the means for generating the global deformation of the top counter bearing element.

13. The machining machine according to claim 11, wherein the top counter bearing element is a top working disk coupled to a top support disk, wherein the means for generating the global deformation of the top working disk comprises a support ring configured to suspend the top support disk, wherein controllable means are arranged between the support ring and a ring section of the top support disk positioned radially to the outside of the support ring and configured to apply a radial force over a perimeter of the support ring to the top support disk with assistance of a force generator, and wherein the control apparatus is configured to adjust the radial force at the force generator in response to distance values measured by the distance measuring apparatus or by pressure values measured by a measuring apparatus.

14. The machining machine according to claim 13, further comprising temperature-controlling channels positioned in at least one of the top and bottom support disks and configured to conduct a temperature-controlling fluid.

15. The machining machine according to claim 14, wherein the temperature-controlling channels are connected to a pressure volume.

16. A method of operating a machining machine, the method comprising: providing a bottom working disk and a top working disk; rotating the bottom working disk and the top working disk relative to each other; providing a working gap defined between the bottom working disk and the top working disk, the working gap configured to allow machining flat work pieces on at least one side; and wherein at least the bottom working disk is configured to locally deform.

17. The method according to claim 16, wherein the bottom working disk is configured to deform locally while processing work pieces to assume a target geometry.

18. The method according to claim 16, wherein a distance between the bottom working disk and the top working disk is measured at one or more locations in the working gap, and wherein the local deformation is generated based on the distance measurement at one or more locations.

19. The method according to claim 16, wherein the top working disk is configured to deform globally while processing workpieces so that the working gap assumes a target geometry.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] An exemplary embodiment of the invention is explained in greater detail below based on figures. In a highly schematic manner:

[0035] FIG. 1 illustrates a sectional view of a part of an embodiment of a double-side machining machine according in a first operating state;

[0036] FIG. 2 illustrates a sectional view of the embodiment of FIG. 1 in a second operating state;

[0037] FIG. 3 illustrates a sectional view of the embodiment of FIG. 1 in a third operating state;

[0038] FIG. 4 illustrates a sectional view of a part of another embodiment of a double-side machining machine;

[0039] FIG. 5 illustrates a plan view of an embodiment of a working disk;

[0040] FIG. 6 illustrates a sectional view of a global deformation of the working disk of FIG. 5 along line A-B; and

[0041] FIG. 7 illustrates a sectional view of a local deformation the working disk of FIG. 5 along line A-B, wherein only half of the cross-sectional view is depicted in segments b) and c) for the sake of visualization.

[0042] The same reference numbers refer to the same objects in the figures unless indicated otherwise.

DETAILED DESCRIPTION OF THE INVENTION

[0043] The double-side machining machine depicted merely as an example in FIGS. 1 to 3 has a top support disk 10 and a bottom support disk 12 that is annular. A top working disk 14 is fastened to the top support disk 10, and a bottom working disk 16 is fastened to the bottom support disk 12. Both the top working disk 14 and the bottom working disk 16 may be annular. Between the annular working disks 14, 16, a working gap 18 is formed in which flat workpieces such as wafers are machined on both sides during operation. The working gap 18 may be annular. The double-side machining machine can for example be a polishing machine, lapping machine, or a grinding machine.

[0044] The top support disk 10, with the top working disk 14, and/or the bottom support disk 12 with it the bottom working disk 16, can be rotatably driven relative to each other by a suitable drive apparatus comprising for example a top drive shaft (not shown), and/or a bottom drive shaft (not shown), as well as at least one drive motor (not shown). The drive apparatus is known per se and will not be described further for reasons of clarity. In a manner which is also known per se, the workpieces to be machined can be held to float in rotary disks in the working gap 18. By suitable kinematics, for example planetary kinematics, it can be ensured that the rotor disks also rotate through the working gap 18 during the relative rotation of the support disks 10, 12, or respectively working disks 14, 16. Temperature-controlling channels (not shown) can be formed in the top working disk 14, or the top support disk 10 and possibly also the bottom working disk 16 or the bottom support disk 12, through which a temperature-controlling fluid such as a temperature-controlling liquid like water can be conducted during operation. This is also known per se and not further described.

[0045] The double-side machining machine shown in FIGS. 1-3 additionally comprises a distance measuring apparatus that is also known per se and is not further described. It can for example function optically or electromagnetically (such as eddy current sensors). In the depicted example, the distance measuring apparatus may comprise three distance measuring sensors that measure the distance between the top working disk 14 and bottom working disk 16 at three radially spaced positions in the working gap. The arrangement of the distance measuring sensors is illustrated in FIG. 1 by the arrows 20, 22 and 24. As can be seen, the distance measuring sensor indicated with reference number 20 measures the distance between the top working disk 14 and the bottom working disk 16 in the region of the radially outer edge of the working gap 18. The measuring sensor indicated with reference number 24 measures the distance between the top working disk 14 and the bottom working disk 16 in the region of the radially inner edge of the working gap 18. The distance measuring sensor indicated with reference number 22 measures the distance between the top working disk 14 and the bottom working disk 16 in the middle of the working gap 18. As shown in FIG. 2, a distance measuring sensor is indicated with reference number 22′ that measures the distance between the bottom working disk 16 and bottom support disk 12 in the middle of the working gap. This distance measuring sensor can be used alternatively to the distance measuring sensors shown in FIG. 1, or in combination with the distance measuring sensors shown in FIG. 1. For example, the distance measuring sensor 22′ can replace the distance measuring sensor 22 shown in FIG. 1. The distance measuring sensors in FIGS. 3 and 4 are not shown for reasons of clarity. The measurements of the distance measuring sensors indicated with reference numbers 20, 22 and 24, or respectively 22′ are applied to a control apparatus 26.

[0046] The bottom working disk 16 in the present case is only fastened in the region of its outer edge and the region of its inner edge to the bottom support disk 12, for example screwed along a divided circle in each case, as illustrated in FIG. 1 with reference numbers 28 and 30. Between these fastening sites 28 and 30, the bottom working disk 16 is contrastingly not fastened to the support disk 12. Instead, an annular pressure volume 32 is located between these fastening sites 28, 30 between the bottom support disk 12 and bottom working disk 16. The pressure volume 32 is connected by a dynamic pressure line 34 to a pressurized fluid reservoir such as a liquid reservoir, in particular a water reservoir (not shown in the figures). In the dynamic pressure line 34, a pump and a control valve can be arranged that can be actuated by the control apparatus 26. In this manner, fluid introduced into the pressure volume 32 can be built up within the pressure volume 32 to a desired pressure that then acts on the bottom working disk 16. The pressure predominating in the pressure volume 32 can be measured by means of a pressure measuring apparatus (not shown). The measurements from the pressure measuring apparatus can also be applied to the control apparatus 26 so that the control apparatus 26 can set a predetermined pressure within the pressure volume 32.

[0047] Due to its freedom of movement between the fastening sites 28, 30, the bottom working disk 16 can be brought locally into a convex shape by setting a sufficiently high pressure within the pressure volume 32 as indicated in FIG. 2 in a dashed line with reference number 36. If a pressure p.sub.0 in the pressure volume 32 is assumed in the operating state in FIG. 1 in which the bottom working disk 16 has a flat shape, the convex deformation shown in FIG. 2 at 36 of the bottom working disk 16 can be achieved by setting a pressure of p.sub.1>p.sub.0. On the other hand, by setting a pressure of p.sub.2<p.sub.0 in the pressure volume 32, a local concave deformation of the bottom working disk 16 can be achieved as indicated by a dashed line in FIG. 3 with reference number 38.

[0048] Viewed in a radial direction, it can be seen that the bottom working disk 16 can assume a local convex shape (FIG. 2), or respectively a local concave shape (FIG. 3), between its inner edge in the region of the fastening site 28 and its outer edge in the region of fastening site 30.

[0049] A means can be provided for globally deforming the top working disk 14 in addition to this local radial deformation of the bottom working disk 16. These means can be designed as explained above, or respectively as described in DE 10 2006 037 490 B4. The top support disk 10 and with it the top working disk 14 fastened thereto are globally deformed so that a global concave or convex shape of the working surface of the top working disk 14 results over the entire cross-section of the top working disk 14. The top working disk 14 can contrastingly remain flat between its radially inner edge and its radially outer edge. The means for adjusting the shape of the top working disk 14 can also be actuated by the control apparatus 26.

[0050] While workpieces are being machined in the working gap 18, the distance measuring sensors 20, 22, 24, or respectively 22′ measure the distance between the top working disk 14 and bottom working disk 16, or respectively between the bottom working disk 16 and bottom support disk 12. In an embodiment, the measurements are taken at regular intervals at their respective measuring site and communicated to the control apparatus 26. If the control apparatus 26 discerns a deviation from the specified working gap geometry, or respectively working disk deformation, in particular from an optimum parallelism between the working surfaces of the top and bottom working disks 14, 16, the control apparatus 26 controls the means for adjusting the shape of the top working disk 14, and/or the pressure fluid supply for the pressure volume 32 to deform the bottom working disk 16 in a suitable manner in order to achieve the desired optimum working gap geometry.

[0051] FIG. 4 shows a double-side machining machine according to another exemplary embodiment that is designed in principle like the double-side machining machine shown in FIGS. 1-3. The example shown in FIG. 4 differs from the example shown in FIGS. 1-3 only in that two top support disks, i.e., support disk 10 and support disk 10′, as well as two bottom support disks, i.e., support disks 12 and 12′ are provided in FIG. 4. The top working disk 14 is fastened to the top support disk 10′ which in turn is held against the top support disk 10. The bottom working disk 16 is fastened to the bottom support disk 12′ in the manner explained with reference to FIGS. 1-3, which in turn is held against the bottom support disk 12. Labyrinthine cooling lines are shown in the top support disk 10′ in FIG. 4 at reference number 40. Labyrinthine cooling lines which are formed in the bottom support disk 12′ are shown at reference number 42. During operation, a cooling liquid such as water is conducted through the cooling lines 40, 42. The bottom cooling lines 42 are moreover connected via a throttle hole 44 to the pressure volume 32. The pressure volume 32 and the bottom cooling lines 42 are supplied by the same pressure fluid supply in the depicted example, for example via a triple distributor. The triple distributor can supply the bottom cooling lines 42 that are kept at a set pressure by the control pressure control valve. The pressure volume 32 is also supplied through the throttle hole 44 with cooling liquid from the cooling lines 42. A third connection of the triple distributor is connected to the pressure volume 32, and the dynamic pressure in the pressure volume 32 can be controlled by a pressure control valve that is pilot-controlled by the control apparatus 26. The maximum dynamic pressure corresponds to the pressure in the cooling lines 42.

[0052] The difference between the local deformation of a working disk according to the invention and the global deformation of a working disk known from the prior art will be further explained with reference to FIGS. 5 to 7. FIG. 5 shows a plan view of an annular working disk as it can be used in the double or single-side machining machine according to the invention. The diameter of the working disk runs between the points A and B drawn in FIG. 5. The turning radius, or respectively the ring width of the annular working disk runs between points A and A′, or respectively between points B and B′.

[0053] FIG. 6 shows a global concave deformation an embodiment of the top working disk in segment a). FIG. 6 shows a global convex deformation of the top working disk in segment c), and FIG. 6 shows the top working disk without a global deformation in segment b). With the exclusively global deformation depicted in FIG. 6, the distance between points A and A′, or respectively the distance between points B and B′ does not discernibly change in the different states of deformation, i.e., the working surface of the working disk is flat between the inner edge A′ and the outer edge A, or respectively between the inner edge B′ and the outer edge B. However, in the different states depicted in FIG. 6, the distance h in an axial direction of the working disk changes between the inner edge A′, or respectively B′ and the outer edge A, or respectively B, in FIG. 6, i.e., in a direction from top to bottom. Without a global deformation, this distance is h=0 (segment b)). Given a concave deformation, this distance is h>0 (segment a)), and given a convex deformation, this distance is h<0 (segment c)).

[0054] FIG. 7 shows an (exclusively) local deformation, also for a top working disk for reasons of clarity. As in segment b) in FIG. 6, a state without any deformation of the top working disk is shown in segment a) of FIG. 7. Segment b) of FIG. 7 shows a local concave deformation of the top working disk, and segment c) of FIG. 7 shows a local convex deformation of the top working disk. As can be seen in segments b) and c) in FIG. 7, the concave or respectively convex shape results in a radial direction between the inner edge A′ and the outer edge A, or respectively between the inner edge B′ and the outer edge B of the working disk, i.e., over the turning radius, or respectively the ring width. With a local deformation as shown in FIG. 7, the distance h′ between any point on the working surface such as the middle of the working surface and the strait connecting line between the inner edge A′ and the outer edge A (or respectively the inner edge B′ in the outer edge B) of the working surface is not zero. In the event of a concave deformation as shown in segment b) in FIG. 7, h′>0. In the event of a convex deformation as shown in segment c) in FIG. 7, h′<0.