Double-sided or single-sided machine tools

Abstract

We provide a double-sided or single-sided machine tool of the desired type that can process workpieces with high quality, reduce the number of defective products, and ensure reliable and cost-effective processing. [Solution] The present invention relates to a double-sided or single-sided machine tool, wherein a first working disc and a counter bearing element are driveable to rotate relative to each other via a rotary drive, and a working gap is formed between the first working disc and the counter bearing element for machining both sides or one side of a flat workpiece, and the double-sided or single-sided machine tool also has a machine base with legs on which the machine base is placed on the floor of the manufacturing area when the double-sided or single-sided machine tool is in a set position, and the machine base supports the first working disc and the counter bearing element, and the legs have sensors for monitoring the alignment of the first working disc.

Description

Technical Field

[0001] The present invention relates to a double-sided or single-sided machining machine, preferably comprising a first working disk at the lower annular part and a counter-bearing element at the upper part, wherein the first working disk and the counter-bearing element can be driven to rotate relative to each other via a rotary drive, a working gap for machining both sides or one side of a flat workpiece is formed between the first working disk and the counter-bearing element, and the double-sided or single-sided machining machine also has a machine base part with legs on which the machine base part is placed on the floor of the manufacturing area when the double-sided or single-sided machining machine is in an installed state, and the machine base part supports the first working disk and the counter-bearing element.

[0002] For example, a flat workpiece such as a wafer is machined on both sides simultaneously with a double-sided machining machine. For this purpose, the double-sided machining machine has an upper working disk and a lower working disk, and a generally annular working gap is formed therebetween, in which the workpiece to be machined is guided during machining. The upper working disk is generally fixed to an upper support disk, and the lower working disk is generally fixed to a lower support disk. For machining, at least one of the working disks, especially together with its support disk, is rotationally driven so that the working disks rotate relative to each other. There are known double-sided machining machines in which a so-called rotor disk is guided in the working gap. The rotor disk generally accommodates a workpiece machined in a floating manner in a circular opening. By appropriate kinematics, it is ensured that the rotor disk also rotates within the working gap during the relative rotation of the working disks. As a result, the workpiece moves along a cycloid path within the working gap. Thereby, particularly stable surface machining is achieved. Machining is performed, for example, by grinding, lapping, or polishing. For example, in a double-sided polishing device, a plurality of silicon wafers, for example, more than 10 silicon wafers, for example, with a diameter of 300 mm, can be machined simultaneously in this way.

[0003] The machining of a workpiece in the prescribed machining steps should be carried out under conditions where the load on the workpiece is as stable as possible over time, and the load should be distributed as uniformly as possible across the entire surface of the disc. An ideal and uniform distribution is achieved when the lower working disc is perfectly horizontally aligned and the drive axes of both discs are parallel, especially coaxially aligned. The alignment of the working discs depends on a series of factors, including the sum of the manufacturing tolerances of the individual parts. Another factor is the surface irregularities of the discs. The more uneven the disc surface, the lower the quality of the workpiece. Another factor is the machine's installation location. For example, an uneven installation surface can cause misalignment between the working discs, which must be corrected with considerable effort. Regarding manufacturing tolerances, continuous efforts are made to minimize the allowable manufacturing error of individual parts. Surface irregularities of the working discs can be improved by appropriate surface planarization processes. To compensate for unevenness in the floor where the machine is installed, the use of height-adjustable legs for the machine base supporting the working discs is known. Such legs may be equipped with dampers.

[0004] The primary goal when setting up the legs is to align the lower working disc horizontally. Once this is done, the upper working disc or counter bearing element is aligned with the surface of the lower working disc, particularly its drive shaft. However, this alignment is set to operate as part of the machine tool setup and is not stable over any given period, but is subject to change due to various factors. For example, the braking elements of the legs are not stable over time, and rather lose elasticity over time, especially with increasing age and usage. The floor of the manufacturing area supporting the machine tool is also not generally the same everywhere, so realignment is necessary, for example, when changing the position of the machine tool. In addition, such floors are often not stable over long periods. This is especially true for the floors of cleanrooms with pedestals or floors located on upper floors. In such cases, the floor surface changes, and the alignment of the machine tool's working disc may change over time. The alignment of the working disc's drive shaft is also affected, for example, by the load on the legs, so unknown changes in its alignment may occur.

[0005] Such changes in the alignment of the work disc are not visible from the outside and are only revealed when the quality of the workpiece deteriorates after the manufacturing process is completed, even though the process parameters remain the same. For example, it is possible to detect general changes in the state of the machining process due to changes in process parameters such as work gap. However, it is not possible to determine here how and to what extent individual factors, such as the aging of machining parts like slurry and work pads (abrasive pads) or misalignment of the work disc, contribute to the changes in state. As a result, deviations from the perfect conditions of process parameters and work disc alignment are only detected later, leading to a considerable number of defective products.

[0006] Misalignment can occur when work discs are tilted relative to each other and are not aligned coaxially with respect to each other. Another problem arises in double-sided or single-sided machine tools where a pivot arm allows the upper work disc to move between a position above the lower work disc and a position away from it. Here, on the one hand, undesirable changes in alignment between the work discs can occur during the rotational movement when the work disc rotates back to the position above the lower work disc. On the other hand, such machine tools often have an asymmetrical weight distribution due to the arrangement of the pivot arm, making it even more difficult to align the work discs relative to each other. This is especially true when the total weight of such machines exceeds 10 tons, for example, around 20 tons.

[0007] The deterioration in workpiece quality is caused by the aforementioned misalignment. During the process of addressing this, the lifespan of the work disk components may be shortened, and surface smoothing may be required frequently, reducing throughput and consequently increasing costs.

[0008] Based on the prior art described above, the objective of the present invention is to provide a double-sided or single-sided machine tool of the desired type that can process workpieces with high quality, reduce the number of defective products, and ensure reliable and cost-effective processing.

[0009] The present invention achieves its objectives by the subject matter of independent claim 1. Advantageous embodiments are shown in the independent claims, specification, and drawings.

[0010] In the case of a double-sided or single-sided machine tool of the type in question, the present invention achieves its objective in that the leg has a sensor for monitoring the alignment of the first working disk.

[0011] Machine tools include, for example, polishing machines, lapping machines, and grinding machines. The workpiece to be processed is, for example, a wafer. A working gap is formed between the first working disk and a counter bearing element, such as a simple weight or pressure cylinder in a single-sided machine tool, or a second working disk in a double-sided machine tool, so that one or both sides of the workpiece to be processed are machined. In a double-sided machine tool, the top and bottom surfaces of the workpiece can be machined simultaneously within the working gap. Accordingly, both working disks may have working surfaces for machining the workpiece surface. In a single-sided machine tool, only one side of the workpiece is machined symmetrically, such as the bottom surface of the lower working disk. In this case, there is only one working disk with a working surface for machining the workpiece surface. In this case, the counter bearing element only serves to form a counter bearing corresponding to the machining by the working disk.

[0012] The workpiece can be accommodated for machining so as to float in a known manner within an opening of a rotor disk placed in a working gap. The first working disk and counter bearing elements are driven to rotate relative to each other during operation, for example, by first and / or second drive shafts and at least one drive motor. Both the counter bearing elements and the first working disk can be driven to rotate, for example, in opposite directions. However, it is also possible to rotate only one of the counter bearing elements or the first working disk. For example, in a double-sided machine tool, the rotor disk can be moved by appropriate kinematics, rotating within the working gap during this relative rotation, so that the workpiece placed within the rotor disk traces a cycloidal path within the working gap. For example, the rotor disk may have teeth on its outer and / or inner edges that mesh with, for example, the relevant teeth of the first working disk. Machines using such so-called planetary motion mechanics are well known.

[0013] The lower first working disc may be designed in an annular shape. The upper counter bearing element, or each second working disc, may also be designed in an annular shape. The first working disc and the counter bearing element, for example, the second working disc, have opposing annular working surfaces, with an annular working gap formed between them. The working surfaces may be covered with a working cover, such as an abrasive cloth. The support discs that hold the working discs may also be designed in an annular shape and have at least an annular support portion to which the working discs are fixed. Multiple support discs may be provided for each working disc. The first working disc and / or the counter bearing element may be designed in one or more layers. The same applies to the support discs that support the first working disc or the counter bearing element.

[0014] In the first working disk and / or counter bearing element, and / or the first support disk supporting the first working disk and / or the second support disk supporting the counter bearing element, a temperature control channel can be designed, through which a temperature control fluid, such as a temperature control liquid, is delivered to control the temperature of each component during operation.

[0015] A machine base supporting a first working disc and a counter bearing element may be designed as a housing. It may also support a rotary drive for rotating the first working disc and / or the counter bearing element. Similarly, the machine base can support a pivot arm which may be provided for rotating the counter bearing element. The machine base can also support a first and / or second support disc which may be provided.

[0016] According to the present invention, the legs on which the machine base rests on the floor of the manufacturing area are equipped with sensors that monitor, particularly indirectly, the alignment of the lower first work disc. The legs may also be equipped with braking elements. The sensors can take various forms, as described below. The present invention is based on the knowledge that the correct alignment of the first work disc for optimal work quality can be inferred, for example, by monitoring the load acting on the legs and / or the vertical position of the legs. Thus, the sensors on the legs can detect early any undesirable deviation of the first work disc from a specified optimal alignment, and therefore, the risk of reduced work quality can be detected early, or, in each case, addressed in a timely manner with appropriate measures to minimize defective products. This allows the sensored legs according to the present invention to reliably distinguish from other possible causes of reduced work quality. For example, by notifying the operator that its alignment has deviated from a specified alignment, appropriate measures can be taken at the appropriate time, and the desired work quality can be maintained. Therefore, according to the present invention, it is easily and reliably guaranteed that the quality of the workpiece will always be maintained, even if the influencing factors acting on the alignment of the first work disc change as described above. The alignment of the counter bearing elements is generally set according to the alignment of the first work disc. For example, the upper counter bearing element can be connected to the drive shaft via a flexible connecting element, such as a curved-tooth coupling, to flexibly adapt to the alignment of the lower first work disc. Thus, when the first work disc is properly aligned, the counter bearing elements are also aligned as desired.

[0017] According to one embodiment, the counter bearing element may preferably be formed by an annular second working disk, and a working gap is formed between the first working disk and the second working disk for machining both sides or one side of a flat workpiece. In particular, if the alignment is correct, the first and second working disks may be arranged coaxially with respect to each other. The first working disk may be fixed to a first support disk supported by a machine base, and / or the second working disk may be fixed to a second support disk supported by a machine base.

[0018] In another embodiment, the counter bearing element may be positioned on a pivot arm located on the machine base and may rotate with the pivot arm relative to the first working disk. A rotary drive for the counter bearing element, positioned on the pivot arm, can be incorporated into the pivot arm. As described above, there are particular challenges with respect to the alignment of the first working disk, especially in the case of machine tools where the weight distribution of the machine base is asymmetrical, particularly in ensuring that correct alignment is maintained, but this problem can be reliably addressed according to the present invention.

[0019] In another embodiment, the leg sensors may include weight sensors that measure the gravitational force acting on each leg. In this embodiment, the weight distribution on different legs of the machine base is taken into consideration. For example, a scale can be considered a weight sensor. As part of the process of setting up the machine to operate, it is possible to set the weight distribution of the legs so that the same gravitational force acts on all legs and then finally align the first working disc. It is also possible to first align the first working disc with any weight distribution among the gravitational forces acting on the legs. In either case, the weight distribution acting on the legs after the setup process is complete can be assumed to be a predetermined weight distribution that is subsequently monitored by the sensors. In particular, the sensors can measure the weight distribution after each manufacturing process is complete, and these measurements can be compared with the measurements after the previous manufacturing process and / or with values ​​related to the predetermined weight distribution, especially the values ​​measured at the predetermined weight distribution. Thus, positional monitoring of the alignment of the lower first working disc is performed in any case after the completion of the manufacturing process, particularly after the counter bearing elements are no longer in contact with the first working disc. If the alignment of the first work disc changes, even if the deviation from the initial alignment is slight, the weight distribution of the legs measurable by the sensor will change. For example, if the deviation exceeds the limit of the initially specified weight distribution, a warning can be issued to the operator, and corrective actions can be taken manually or automatically to reset the alignment of the first work disc for optimal work quality.

[0020] In another embodiment, the sensor may include an optical sensor, each sensor optically measuring the position of the leg, particularly the vertical position of the leg. The optical sensor may include, for example, a laser sensor that measures the position of the leg, preferably using the measurement of propagation time. In particular, an optical transmitter, such as a laser, may be provided that directs light radiation toward a reflector. The propagation time of the radiation from the transmitter to the reflector and then to the receiver of the radiation allows the receiver to measure, for example, the position of the transmitter, but the distance between the transmitter and the reflector, and therefore, for example, the vertical position of the support leg. In this embodiment, the fact that misalignment of the first work disk can lead to, for example, a change in the height of the individual leg compared to the other legs is taken advantage of. This can be recorded by measurement, and as a result, appropriate measures can be taken to maintain the specified alignment for optimal work quality, as described above.

[0021] Double-sided or single-sided machine tools may also be equipped with an evaluation device that receives measurement data from sensors. The evaluation device may be designed to output a warning signal if a deviation in the alignment of the first work disk from a specified alignment is detected. Based on such a warning signal, the operator can take measures to realign the first work disk optimally. For this purpose, for example, the position of the first work disk can be changed, such as vertical movement, lateral movement, tilting movement, and / or the position of the legs can be changed, such as vertical movement of the legs. Thus, the position of the first work disk may be changed, for example, vertical adjustment and / or lateral adjustment. Alternatively, for example, the first work disk may be tilted to correct a non-coaxial alignment of the rotation axis of the first work disk and the counter bearing element.

[0022] According to another embodiment, the evaluation device can be designed to operate the double-sided or single-sided machine tool so that, when it is detected that the alignment of the first working disk has deviated from a specified alignment, the alignment of the first working disk is returned to the specified alignment. In this embodiment, when a deviation from the specified alignment is detected, automatic realignment can be performed to maintain optimal work quality at all times. For this purpose, the evaluation device can operate an appropriate adjustment device, which can adjust the position of the first working disk and / or legs in the manner described above.

[0023] In another embodiment, the first support disc supporting the first work disc and / or the first work disc and / or legs may include an adjustment device that can be operated by an evaluation device to cause the alignment of the first work disc to correspond again to a specified alignment.

[0024] In particular, according to practical embodiments, the adjustment device may include at least one adjustment element, such as an adjustment wedge, which is translationally movable by an adjustment drive, and whose translational movement allows the first work disk and / or the first support disk supporting the first work disk and / or legs to be height-adjustable and / or laterally adjustable and / or tiltable. The adjustment device may include, in particular, a plurality of adjustment elements of the type that are translationally movable by an adjustment drive. The translational movement of the adjustment elements allows the position, for example, the height of a desired part to be adjusted in a mechanically simple manner in order to conform the alignment of the first work disk.

[0025] According to another embodiment, the defined alignment may be the alignment of the first working disk configured to operate as part of the setup of a double-sided or single-sided machine tool. Thus, the first working disk is optimally aligned before the machining process, and this alignment is applied as the target alignment. If the leg sensors detect a change compared to this target alignment, countermeasures can be taken in the manner described above. As described above, the sensors can record measurement values characterizing the alignment of the first working disk after each manufacturing process, and these measurement values can be compared to the measurement values after the preceding manufacturing process and / or the measurement values related to the defined alignment, particularly the values measured for the defined alignment. As explained, monitoring the alignment of the lower first working disk for positioning is carried out in any case after completion of the manufacturing process, particularly after the counter-bearing element has ceased to contact the first working disk.

[0026] Exemplary embodiments of the present invention will be described in more detail below with reference to the figures.

Brief Description of the Drawings

[0027] [Figure 1] Side view of the double-sided machine tool according to the present invention in a first operating state. [Figure 2] View of the double-sided machine tool of FIG. 1 in a second operating state. [Figure 3] Top view of the double-sided machine tool according to FIG. 1 in the operating state from FIG. 2. [Figure 4] View in a further operating state of FIG. 3. [Figure 5] Cross-sectional view of the adjustment device of the double-sided machine tool according to the present invention according to a first exemplary embodiment. [Figure 6] Cross-sectional view of the adjustment device of the double-sided machine tool according to the present invention according to another exemplary embodiment.

Modes for Carrying Out the Invention

[0028] Unless otherwise specified, the same reference symbol refers to the same object in the diagram.

[0029] The double-sided machine tool shown in Figures 1 to 4 as an example has a machine base 10 located on the floor 14 of the manufacturing area via a plurality of legs 12. The machine base 10 is designed, for example, as a housing and supports an annular lower first support disc 16, which in turn supports an annular lower first work disc 18. Furthermore, the machine base 10 is positioned in a pivot housing 20 and supports a pivot arm 22 that supports an annular upper second support disc 24, which in turn supports an annular upper second work disc 26. The upper second support disc 24 and the upper second work disc 26 are rotatable, for example, around a drive shaft 28 via a rotary drive positioned in the pivot arm 22. The lower first support disc 16 and its associated lower first work disc 18 are also rotatable, for example, in opposite directions to the upper second support disc 24 and the upper second work disc 26 using a rotary drive (details not shown). An annular working gap is formed between the working discs 18 and 26. Figure 1 shows the working discs 18 and 26 separated from each other in the axial direction and not in contact with each other. Figure 2 shows the working discs 18 and 26 pressed against each other. By rotating the working discs 18 and 26 in opposite directions, it is possible to perform processes such as grinding, lapping, and polishing on a workpiece, for example, that is suspended on a rotor disc, in the annular working gap using well-known methods.

[0030] As can be seen by comparing Figure 1 and Figure 2, the pivot arm 22 is height-displaceable to adjust between the operating states of Figure 1 and Figure 2. Looking at Figures 3 and 4, it can also be seen that, as shown in Figure 1, after the working discs 18 and 26 are no longer in contact, the pivot arm 22 can rotate together with the pivot housing 20 to rotate the upper second support disc 24 and together with the upper second working disc 26 between a position facing the lower first working disc 18 and a position away from it, particularly to place a workpiece to be machined on the rotor disc.

[0031] Each leg 12 is equipped with a sensor 30, which may be a weight sensor 30 that measures the gravitational force acting on each leg 12. The measurements from the sensors 30 are applied to the evaluation device 32 of the double-sided machine tool. For example, in the state shown in Figure 1, the lower first working disk 18 can be optimally aligned horizontally together with the lower first support disk 16. After this alignment is complete, the sensors 30, for example, activated by the evaluation device 32, can measure the gravitational force acting on each leg 12. These measurements are stored by the evaluation device 32 in particular as target measurements for a specified alignment of the lower first working disk 18. Then, in the state shown in Figure 2, a workpiece can be machined. After this manufacturing process is complete and the working disks 18, 26 are no longer in contact with each other, the sensors, for example, activated again by the evaluation device 32, can measure the gravitational force acting on each leg 12 again. These measurements can be compared by the evaluation device 32 to the previously stored target measurements.

[0032] For example, if the weight distribution between the legs 12, measured by the sensor 30 after the manufacturing process is completed and the work discs 18 and 26 have been separated, changes compared to the weight distribution of the optimal alignment of the work disc 18, which was set at the start of this or a previous processing process, the evaluation device 32 can output a warning signal. Based on this, for example, the operator can adjust the alignment of the first work disc 18 until the weight distribution measured by the sensor 30 corresponds to a specified value again, and therefore the alignment corresponds to a specified alignment again. Alternatively or additionally, the sensor 30 may also include, for example, an optical sensor 30 that measures the vertical position of the legs 12, and based on this, deviations from the specified alignment can be detected.

[0033] Figures 5 and 6 show an adjustment device that allows for the alignment of the upper second work disk 26 to be adjusted, for example, by setting the height of the upper second support disk 24 and the upper second work disk 26. In the illustrated example, an adjustment element 34, in particular an adjustment wedge 34 that can be manually retracted or extended in a conical adjustment holder 38 via an adjustment screw 36 in the example shown in Figure 5, is provided for this purpose. For example, the rotation of the screw 36 causes the adjustment wedge 34 to translate into the conical adjustment holder 38, thereby moving the second support disk 24 and the second work disk 26 downward in Figure 5, and as a result, the alignment of the second work disk 26 can be set in a desired manner. The alignment of the lower first support disk 16 and the lower first work disk 18 can be set to correspond using such an adjustment device.

[0034] Figure 6 shows a further exemplary embodiment in which an adjustment screw 36 and its associated adjustment wedge 34 are translatably adjustable relative to an adjustment holder 38 by an adjustment drive 40. In the example shown in Figure 5, for example, an operator can manually actuate the adjustment screw 36 to set the alignment between the work disks 18 and 26. In the example shown in Figure 6, if the evaluation device detects an unacceptable deviation in the alignment measured by the sensor 30, the adjustment screw 36 can be automatically actuated by, for example, the evaluation device 32 via the adjustment drive 40 until the alignment corresponds to the specified alignment again. The alignment of the lower first support disk 16 and the lower first work disk 18 can then be set in correspondence. [Explanation of Symbols]

[0035] 10 Machine base section 12 legs 14 beds 16. First support disk 18. First working disk 20 Pivot Housing 22 Pivot Arm 24 Second support disk 26. Second working disk 28 drive shafts 30 sensors 32 Evaluation device 34 Adjustment Elements 36 Adjustment screw 38 Adjustment holder 40 Adjusted Drive

Claims

1. A double-sided or single-sided machine tool, preferably comprising an annular lower first working disc (18) and an upper counter bearing element (26), wherein the first working disc (18) and the counter bearing element (26) are driveable to rotate relative to each other via a rotary drive, and a working gap is formed between the first working disc (18) and the counter bearing element (26) for machining both sides or one side of a flat workpiece, and the double-sided or single-sided machine tool also has a machine base (10) comprising legs (12) on which the machine base (10) rests on the floor (14) of a manufacturing area when the double-sided or single-sided machine tool is in a set position, the machine base (10) supports the first working disc (18) and the counter bearing element (26), wherein the legs (12) are equipped with sensors (30) for monitoring the alignment of the first working disc (18).

2. The double-sided or single-sided machine tool according to claim 1, characterized in that the counter bearing element (26) is preferably formed by an annular second working disc (26), and the working gap is formed between the first working disc and the second working disc (18, 26) for machining both sides or one side of a flat workpiece.

3. The double-sided or single-sided machine tool according to claim 1, characterized in that the first working disc (18) is fixed to a first support disc (16) which is also supported by the machine base (10), and / or the second working disc (26) is fixed to a second support disc (24) which is also supported by the machine base (10).

4. The double-sided or single-sided machine tool according to claim 1, wherein the counter bearing element (26) is positioned on a pivot arm (22) located on the machine base (10) and is rotatable relative to the first work disk (18) using the pivot arm.

5. The double-sided or single-sided machine tool according to claim 4, wherein a rotary drive for the counter bearing element (26), which is positioned on the pivot arm (22), is incorporated into the pivot arm (22).

6. The double-sided or single-sided machine tool according to claim 1, wherein the sensor (30) is a weight sensor (30) that measures gravity acting on the leg (12).

7. The double-sided or single-sided machine tool according to claim 1, wherein the sensor (30) is an optical sensor (30) that optically measures the position of the leg (12), particularly the vertical position of the leg (12).

8. The double-sided or single-sided machine tool according to claim 7, wherein the optical sensor (30) preferably includes a laser sensor that measures the position of the leg (12) via a measurement of propagation time.

9. The double-sided or single-sided machine tool according to claim 1, further comprising an evaluation device (32) for receiving measurement data from the sensor (30).

10. The double-sided or single-sided machine tool according to claim 9, wherein the evaluation device (32) is designed to output a warning signal when it detects a deviation in the alignment of the first work disk (18) from a specified alignment.

11. The double-sided or single-sided machine tool according to claim 9, wherein the evaluation device (32) is designed to operate the double-sided or single-sided machine tool so that the alignment of the first work disk (18) returns to the specified alignment when it is detected that the alignment of the first work disk (18) has deviated from a specified alignment.

12. The double-sided or single-sided machine tool according to claim 11, wherein the first working disc (18) and / or the first supporting disc (16) supporting the first working disc (18) and / or the leg (12) is equipped with an adjustment device that can be operated by the evaluation device (32) so that the alignment of the first working disc (18) corresponds again to the specified alignment.

13. The double-sided or single-sided machine tool according to claim 12, wherein the adjustment device (34) is capable of translational movement by an adjustment drive (40), and the translational movement thereof provides at least one adjustment element such that the first work disk (18) and / or the first support disk (16) supporting the first work disk (18) and / or the leg (12) is height adjustable and / or laterally adjustable and / or tiltable.

14. The double-sided or single-sided machine tool according to claim 10, wherein the aforementioned alignment is the alignment of the first working disk (18) configured to operate as part of the setup of the double-sided or single-sided machine tool.

15. The double-sided or single-sided machine tool according to claim 1, wherein the double-sided or single-sided machine tool is a double-sided or single-sided polishing machine, a double-sided or single-sided lapping machine, or a double-sided or single-sided grinding machine.

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