METHOD FOR OPERATING A DOUBLE-SIDED PROCESSING MACHINE AND DOUBLE-SIDED PROCESSING MACHINE

Abstract

A method for operating a double-sided processing machine having a top working disk and a bottom working disk which rotate relative to each other and define a working gap between them that is configured for processing flat workpieces is disclosed. The method includes performing a heating step by heating at least the working disks to an operating temperature using a heating apparatus. Then processing the workpieces using one or more processing steps after completion of the heating step.

Claims

1. A method for operating a double-sided processing machine having a top working disk and a bottom working disk which rotate relative to each other and define a working gap between them that is configured for processing flat workpieces, the method comprising: performing a heating step comprising heating at least the working disks to an operating temperature using a heating apparatus; and processing the workpieces using one or more processing steps after completion of the heating step.

2. The method according to claim 1, further comprising conducting a heated heating liquid into the working gap during the heating step.

3. The method according to claim 2, wherein the conducting of the heating liquid into the working gap is done through supply openings for a slurry.

4. The method according to claim 1, rotating the top and bottom working disks in a same direction during the heating step.

5. The method according to claim 1, further comprising holding the working disks during the heating step using one of (1) spacers between the working disks and (3) locking a mount of one of the top and bottom working disks at a defined distance from each other.

6. The method according to claim 1, wherein the heating step further comprises conducting a heated heating liquid through tempering channels positioned in at least one of the top working disk and the bottom working disk.

7. The method according to claim 1, wherein the heating step comprises heating at least the top and bottom working disks to an operating temperature using at least one electrical heating mat.

8. The method according to claim 1, further comprising: measuring a temperature of at least one of the top working disk and the bottom working disk during the heating step; and terminating the heating step after the operating temperature has been reached.

9. A double-sided processing machine comprising: a top working disk; a bottom working disk; a working gap configured for processing flat workpieces defined between the top and bottom working disk; and a heating apparatus configured to heat at least one of the top and bottom working disks to an operating temperature in a heating step, wherein the top and bottom working disk are configured to rotate relative to each other, and wherein the heating step is performed before a processing step for processing the flat workpieces.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] An exemplary embodiment of the invention is explained in greater detail below based on figures. Schematically:

[0024] FIG. 1 illustrates a sectional view of an embodiment of a double-sided processing machine; and

[0025] FIG. 2 illustrates a diagram of an embodiment of a method of operating a double-sided processing machine.

[0026] The same reference signs refer to the same objects in the figures unless indicated otherwise.

DETAILED DESCRIPTION OF THE INVENTION

[0027] The double-sided processing machine shown in FIG. 1, in which it can be, for example, a double-sided polishing machine, has an annular top working disk 10 and a likewise annular bottom working disk 12. Between the working disks 10, 12, an annular working gap 14 is formed in which flat workpieces, for example, semiconductor wafers, can be processed, for example polished. As explained, the workpieces can be mounted in a floating manner in recesses of what are known as rotor disks. The rotor disks can be moved along a circular path through the working gap 14 and in doing so rotate about their own axis. For this purpose, the rotor disks can roll, for example, on sprockets on the inner and/or outer edge of the working gap 14. This is known per se and is therefore not explained in more detail.

[0028] The top working disk 10 is fastened to a top support disk 16, and the bottom working disk 12 is fastened to a bottom support disk 18. During processing of workpieces in the working gap 14, the top support disk 16 and the bottom support disk 18, and with them the top working disk 10 and the bottom working disk 12, are rotated relative to each other about an axis of rotation 20 by means of a rotary drive which is not shown in more detail. For example, the working disks 10, 12 or respectively the support disks 16, 18 can be driven to rotate in opposite directions.

[0029] In FIG. 1, various further components of the top and bottom working disks 10, 12 are shown, wherein they are shown only for one of the working disks 10, 12 for reasons of clarity. It should be understood that the corresponding components, described in more detail in the following, can be configured in both working disks 10, 12.

[0030] In the example shown, the top working disk 10 has supply lines 22 for supplying a slurry to the working gap 14. The supply lines 22 each have supply openings 23 opening into the working gap 14. In addition, in FIG. 1 distance sensors 24, for example, eddy current sensors 24, are provided in the top working disk 10 and measure the distance to the workpieces to be processed and thus their thickness at different radial locations of the working gap 14 during workpiece processing. In FIG. 1, multiple temperature sensors 26 are also designed in the top working disk 10, which sensors measure the temperature at least of the top working disk 10 in particular during a heating step but also, for example, during a processing step. As explained, temperature sensors can also be provided in the bottom working disk 12. The same applies to the top support disk 16 and the bottom support disk 18. In the example shown, the measurement results from the temperature sensors 26 are applied to a control and/or regulation apparatus 28 of the double-sided processing machine. This controls or respectively regulates the operation of the double-sided processing machine, including a heating step still to be explained in the following.

[0031] A heating element 30 is also shown schematically in the bottom working disk 12. The heating element 30 can be, for example, an electrical heating element 30, for example an electrical heating mat 30. However, the heating element 30 can also be a, for example, labyrinthine arrangement of tempering channels 30 through which heated heating liquid is conducted in a heating step, as will also be explained below. The heating element 30 can in turn also be configured in the top working disk 10. The same applies to the top support disk 16 and the bottom support disk 18.

[0032] In the method according to the invention, before a processing step is performed for processing workpieces in the working gap 14, the temperature of the top working disk 10 and the bottom working disk 12 is first brought to a specified operating temperature in a heating step. This can be controlled or respectively regulated by the control and/or regulation apparatus 28. For example, heated heating liquid can be conducted into the working gap 14 in the heating step through the supply lines 22 and the supply openings 23. The working disks 10, 12 and the support disks 16, 18 can be rotated in the working gap 14 during the supply of the heating liquid. During the heating step, the working disks 10, 12 can be held at a defined distance from each other, for example by locking a mount of the top working disk 10 and/or of the bottom working disk 12. The temperature sensors 26 can detect when the specified operating temperature has been reached. The control and/or regulation apparatus 28 can then terminate the heating step. Subsequently, workpieces can be processed in one or more processing steps, in particular material-removing processing, for example, polishing, lapping, or grinding.

[0033] Alternatively or additionally, heated heating liquid can be conducted through the tempering channels 30 in the heating step and the temperature of the working disks 10, 12 can thereby be heated to the specified operating temperature. It is further possible alternatively or additionally to heat at least the working disks 10, 12 to the operating temperature in the heating step by means of the electrical heating apparatus 30, in particular the heating mat 30. Detecting the operating temperature and the corresponding termination of the heating step can take place, as explained above, by the control and/or regulation apparatus 28. The control and/or regulation apparatus 28 can use the temperature of the supplied heating liquid, the heating output of the electrical heating apparatus 30 and the duration of the heating step as control and/or regulation parameters. When the working disks 10, 12 are rotated, the rotational speed of the working disks 10, 12 can also be used.

[0034] FIG. 2 shows a diagram with results of a heating according to the prior art and according to the disclosed device/method. The GBIR value is shown normalized in each case over the number of heating runs of the double-sided processing machine. The curve 32 refers to the case in which the double-sided processing machine was not operated for three nights and days at room temperature and then was used to process workpieces in processing steps without a heating step according to the invention. It is shown that three heating runs were required in order to reach a specified GBIR value, which should be as close to 1 as possible in the normalized version.

[0035] The curve 34 describes a case corresponding to the curve 32, wherein the double-sided processing machine stood idle, however, for only one night at room temperature. Here, the number of required heating runs until the desired GBIR value is reached is shortened to one run. However, a corresponding throughput loss or respectively a corresponding cost increase is still registered.

[0036] The curve 36 shows the results for a double-sided processing machine which has stood idle for one night at room temperature and in which a heating step according to the invention was performed before the first processing step (run one). The curve 36 shows that the first processing run here already has the desired GBIR value. Corresponding throughput loss or respectively corresponding cost increases could be avoided.

LIST OF REFERENCE SIGNS

[0037] 10 Top working disk [0038] 12 Bottom working disk [0039] 14 Working gap [0040] 16 Top support disk [0041] 18 Bottom support disk [0042] 20 Axis of rotation [0043] 22 Supply lines [0044] 23 Supply openings [0045] 24 Distance sensors [0046] 26 Temperature sensors [0047] 28 Control and/or regulation apparatus [0048] 30 Heating element [0049] 32 Curve [0050] 34 Curve [0051] 36 Curve