JP2010221348A - Double-sided polishing device and machining method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-way double-sided polishing device of a planetary gear type that can increase the scale of the device and can improve the high accuracy (thickness accuracy, flatness) of machining quality of the device which is in a trade-off relation, and also enables process automation, and a machining method. <P>SOLUTION: The double-sided polishing device has a plurality of pulleys 7 and 9 disposed on a ring 8 and suspending plate 10 which are mounted to an upper surface plate 6, and has an endless wire rope 12 stretched among the pulleys 7 and 9 so as to support a vertical load of the upper surface plate 6. The upper surface plate 6 is vertically moved to make workpieces 5 contact with the most suitable load based on an output from a tension sensor 17 so that an increase of the scale of the device and the high accuracy of machining quality are achieved by improving the following performance of the upper surface plate 6 relative to the workpieces 5. Furthermore, the polishing process automation is enabled as the upper surface plate 6 can be attached to the workpieces 5 based on the output from the tension sensor 17. The machining method is carried out using the double-sided polishing device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a three-way planetary gear type double-side polishing apparatus that performs planar processing such as lapping and polishing, and a processing method thereof.

  The double-side polishing apparatus is an apparatus that performs planar processing such as lapping and polishing on both surfaces of a workpiece. A 4-way planetary gear type double-side polishing apparatus, which is a specific example of such a double-side polishing apparatus, will be described with reference to the drawings. FIG. 15 is a perspective view showing an essential part of a conventional 4-way planetary gear type double-side polishing apparatus, and FIG. 16 is a sectional view of the essential part.

  15 and 16, reference numeral 101 denotes an annular lower surface plate that is rotationally driven by a lower surface plate rotation drive unit (not shown), 102 is a carrier having a tooth surface on the outer peripheral surface, and 103 is rotationally driven by an internal gear rotation drive unit (not shown). 104, a sun gear rotated by a sun gear rotation drive unit (not shown), 105 a work, 106 a support, 107 a suspension plate, 108 a universal joint, 109 an annular upper surface plate, 110 Is a drive shaft that is rotationally driven by an upper surface plate rotation drive unit (not shown), and 111 is a drive key that is attached to the key groove 110 a of the drive shaft 110 and connects the upper surface plate 109 and the drive shaft 110.

  When using this double-side polishing apparatus, a plurality of carriers 102 are meshed with the internal gear 103 and the sun gear 104 on the lower surface plate 101 and arranged radially, and workpieces are placed in the plurality of workpiece holding holes of these carriers 102. 105 is attached. Further, the upper surface plate 109 suspended in a pendulum shape by the universal joint 108 via members such as the support column 106 and the suspension plate 107 is lowered by an upper surface plate elevating unit (not shown) such as an air cylinder, An appropriate load is applied to the workpiece 105 mounted on the carrier 102.

  Further, the drive key 111 attached to the upper surface plate 109 and the drive shaft 110 are coupled. The keyway 110a of the drive shaft 110 is provided in the vertical direction, and the drive key 111 and the keyway 110a of the drive shaft 110 transmit rotational driving force, but can be moved in the vertical direction. For this reason, the upper surface plate 109 naturally descends downward by gravity following the workpiece 105 even after connection. The support shaft attached to the universal joint 108 is configured to be rotatable by a bearing (not shown), and the upper surface plate 109 rotates as the drive shaft 110 rotates.

  When the workpiece 105 is polished, the lower surface plate 101 and the upper surface plate 109 are rotated in opposite directions while supplying abrasive particles from an abrasive particle supply hole (not shown) provided in the upper surface plate 109. Further, by rotating the internal gear 103 and the sun gear 104, the carrier 102 on which the work 105 sandwiched between the lower surface plate 101 and the upper surface plate 109 is rotated and revolved, and both surfaces of the work 105 are polished. .

  The lower surface plate 101, the internal gear 103, the sun gear 104, and the upper surface plate 109 are rotated by the lower surface plate rotation drive unit, the internal gear rotation drive unit, the sun gear rotation drive unit, and the upper surface plate rotation drive unit, respectively. Is controlled, and the optimum polishing is performed by adjusting the rotation speed. The term “polishing” as used herein is a general term for abrasive processing such as lapping and polishing including grinding. The double-side polishing apparatus shown in FIGS. 15 and 16 is composed of four motion elements including the rotation of the lower surface plate 101, the rotation of the upper surface plate 109, the rotation of the carrier 102, and the revolution of the carrier 102. -It is called a double-side polishing apparatus of the way type. Such a conventional double-side polishing apparatus is as described above.

  Now, for such a double-side polishing apparatus, there is an increasing demand for higher processing quality (thickness accuracy, flatness, etc.) in recent years (higher quality accuracy). In the prior art described with reference to FIG. 15 above, an upper surface plate raising / lowering mechanism such as an air cylinder is used to detect a load fluctuation of the upper surface plate 109 as a change in internal pressure in the air cylinder via the suspension plate 107 and the cylinder rod. Thus, the fluid pressure value is controlled so as to coincide with the set value, and it is difficult to follow the uneven load acting on the upper surface plate 109 or a small load fluctuation. In addition, in the low load region such as when the upper surface plate 109 is placed, there is an influence such as internal friction of the air cylinder, so that it is difficult to accurately control the surface pressure.

Furthermore, as another conventional technique for improving the quality and accuracy of the double-side polishing apparatus, for example, in Patent Document 1 (Japanese Patent No. 3262808, the name of the “planetary gear system plane processing machine”), Similar to the above, but with a structure in which the upper surface plate suspension plate and the upper surface plate are connected by an endless rope etc. via upper and lower pulley groups, compared to the conventional 4-way system. It has a structure with improved followability to the workpiece and lower surface plate. In this method, the upper surface plate does not rotate and is called a 3-way method.
In patent document 2 (Japanese Patent Publication No. 7-75827, the name of the invention “planar polishing apparatus with a working pressure correction mechanism”), in an upper surface plate lifting mechanism such as an air cylinder, between an air cylinder rod and a suspension plate. A load meter is installed to control the fluid pressure supplied to the air cylinder by measuring the load on the upper surface plate and suspension plate at the top of the suspension plate.
Patent Document 3 (Japanese Patent Publication No. 63-009943, entitled “Lapping Device”) employs a configuration in which the distance between upper and lower surface plates is measured by a non-contact sensor to detect the workpiece thickness during processing. ing.

Further, in order to improve work processing efficiency and establish a highly reliable history management method, there is an increasing demand for automation of the polishing process as well as an increase in the size of the double-side polishing apparatus as described above.
As an example of the polishing process, there are a process of loading a workpiece onto a processing carrier, a polishing process, a workpiece removal after polishing, a workpiece cleaning process, and a workpiece storing process. It was technically difficult to automate the work of loading the work into the carrier holding hole and the visual confirmation of the work loaded state before processing. Furthermore, there have been problems such as countermeasures against crashes in which abnormal vibration occurs in the upper surface plate during machining due to poor loading of workpieces or variations in machining conditions.

  Examples of conventional techniques for automating the polishing process of a double-side polishing apparatus include, for example, Patent Document 4 (Japanese Patent Laid-Open No. 7-112365, title of invention “floating abrasive polishing apparatus”), Patent Document 5 (Japanese Patent Laid-Open No. Hei 2- No. 106269, the title of the invention “Polishing machine having an abnormal loading detector”), Patent Document 6 (Japanese Patent Application Laid-Open No. 2008-36802, the title of the invention “Duplicate detection of workpiece and carrier in double-side polishing apparatus and double-side polishing apparatus” The invention described in “Method”) is known.

Japanese Patent No. 3262808 Japanese Patent Publication No. 7-75827 Japanese Patent Publication No. 63-009943 JP-A-7-112365 Japanese Patent Laid-Open No. 2-106269 JP 2008-36802 A

The conventional techniques described in Patent Documents 1, 2, and 3 that describe high quality accuracy have the following problems.
In the prior art planetary gear type plane processing machine described in Patent Document 1, in order to hold the upper and lower surface plates in parallel, a 3-way planetary gear method in which the upper surface plate is suspended and supported by a wire rope is adopted. In this case as well, the load fluctuation of the upper surface plate is detected as a change in the internal pressure of the air cylinder via the suspension plate and cylinder rod, and the fluid pressure value is controlled so that it matches the set value. In addition, it is difficult to accurately detect load fluctuations acting on the upper surface plate, and at the same time, in the low load area such as when landing, it is due to the effects of internal friction such as air cylinders and uneven loads acting on the upper surface plate. At present, accurate control is difficult due to the influence of moment force.

  In the conventional planar polishing apparatus with a processing pressure correction mechanism of Patent Document 2, a load made of a strain gauge is installed at the tip of the piston rod of the upper cylinder to directly apply the load acting on the upper platen, that is, the surface pressure on the workpiece. The fluid pressure acting on the cylinder is constantly controlled so that this applied load maintains the target value by measuring, but compared to the load that the sensor should support on its axis, The load level at the time was small, and the low load was measured using an expensive sensor with a large capacity for measuring the load of the upper surface plate including the suspension plate, and it was difficult to ensure sufficient control accuracy. It was. In addition, a universal joint is applied to the connecting part between the lower part of the piston rod and the upper surface plate suspension plate, but the moment load due to one piece hitting the upper surface plate may be affected as a disturbance or in the low load range. There was a concern that a shocking load might be applied to the workpiece when the upper platen was placed due to the inability to detect and the problem of the support structure on the upper platen.

  In the prior art lapping apparatus described in Patent Document 3, accurate detection of the workpiece thickness is attempted using a sensor that measures the distance between the upper and lower surface plates in a non-contact manner, but the polishing apparatus itself is increased in size. Along with this, there is a concern that the influence of uneven wear on a large surface plate and changes in the shape of the surface plate due to heat generation during processing adversely affect the measurement accuracy of the entire workpiece.

  With regard to this "higher quality", semiconductor wafers are currently required to increase the size of workpieces and increase the number of workpieces per batch, but even under such circumstances, improvements in machining thickness accuracy, etc. are required. For example, there is a need to satisfy both the increase in size and high quality of equipment that are in a trade-off relationship.

In particular, in a large-sized double-side polishing machine, while holding the upper and lower surface plates parallel to all the workpieces in the carrier, the predetermined surface pressure applied to the workpiece surface is set and held with high accuracy and uniformity. The workpiece thickness is accurately detected and the polishing process is terminated when the target workpiece thickness is reached, and it is very difficult to achieve both high quality accuracy and large size.
In the prior art described in these Patent Documents 1, 2, and 3, it is difficult to improve the quality when the apparatus is enlarged due to the above-described problems, and both the enlargement of the apparatus and the improvement of the processing quality are compatible. It was difficult.

Further, the conventional techniques described in Patent Documents 4 and 5 describing the automation of the polishing process have the following problems.
In the prior art floating abrasive type polishing apparatus described in Patent Document 4, abnormal vibration occurs in the upper surface plate during processing due to abnormal loading of the workpiece or fluctuations in processing conditions, and the work carrier breaks or the upper and lower surface plates As a means for avoiding damage, vibration measurement that occurs at the time of abnormality is performed by detection means attached to the upper surface plate. However, the structure of the polishing equipment does not include a support structure that does not restrain the minute vibrations caused by the polishing reaction force as the support structure of the upper surface plate and the followability of the upper surface plate with respect to the workpiece and the lower surface plate. Therefore, it was difficult to accurately measure the vibration of the heavy surface plate.

  Further, the polishing machine having the prior art abnormal loading detector of Patent Document 5 is provided with a sensor device for separately detecting the lowering position of the upper surface plate around the upper surface plate. Securing and restricting the installation location increases costs and makes installation complicated.

Moreover, the double-side polishing apparatus and the method for detecting the overlap between the workpiece and the carrier in the double-side polishing apparatus of Patent Document 6 have the following problems.
・ It was necessary to install additional measurement sensors to check the workpiece loading status.
-In conventional 4-way type polishing machines where the upper platen also rotates, the upper platen and lower platen are normally controlled by a controller that only controls the rotation speed, and the carrier can be positioned, but the upper platen The board could not be positioned. For this reason, it is difficult to place the sensor position installed on the upper surface plate at a fixed position with respect to the specific position of the positioned carrier. Accordingly, it is necessary to newly provide a device for positioning the upper surface plate that is always accompanied by the raising / lowering operation, which causes technical difficulties and increases the cost.
・ As a structural problem, the conventional 4-way polishing machine that rotates the upper platen supports the upper platen when detecting the change in the thickness of the workpiece on the carrier when the upper platen is mounted. Since the followability is insufficient as a mechanism, malfunctions are likely to occur.
-In the normal processing method, when the upper surface plate is mounted, there is a method of distributing and reducing the load acting on the workpiece from the upper surface plate by rotating and rotating the carrier while supplying the polishing liquid. In addition, it was necessary to set the landing load of the upper surface plate sufficiently small. When the above requirements were insufficient, there was a concern that the workpiece would be damaged.

  In addition, special consideration should be given to the method of landing on the upper surface plate. In other words, unless measures are taken to minimize damage to the workpieces that have come off the holding holes and have run on the carrier surface, these workpieces will be damaged, and it will take much time to recover. However, the invention relating to such means has not been a prior art.

  In addition, when the above-mentioned means cannot detect an abnormality (when the workpiece thickness is small, when the workpiece rides on a minute workpiece fragment or slurry in the holding hole, or when a malfunction occurs) When the machining process is continued as it is, a crash occurs and there is a concern that the workpiece, the carrier, the surface plate and the like are seriously damaged.

  Therefore, the present invention has been made in view of the above-described problems, and in addition to an increase in the size of the apparatus and a high processing quality (thickness accuracy, flatness) in a trade-off relationship, the polishing process is automated. It is an object of the present invention to provide a three-way planetary gear type double-side polishing apparatus and processing method to be realized.

A double-side polishing apparatus according to claim 1 of the present invention includes:
The upper surface plate is moved up and down by the upper surface plate elevating unit, the lower surface plate is rotated by the lower surface plate rotation drive unit, the internal gear is rotated by the internal gear rotation drive unit, and the sun gear is rotated by the sun gear rotation drive unit. A plurality of carriers having tooth surfaces on the outer periphery and a plurality of workpiece holding holes formed in the rotational direction are meshed between a sun gear and an internal gear arranged in a horizontal plane. With the front and back surfaces of the workpiece inserted into the workpiece holding hole sandwiched between the lower surface plate and the upper surface plate, the sun gear and the internal gear are rotated to planetarily move the carrier, and the lower surface plate In a three-way planetary gear type double-side polishing apparatus that wraps or polishes a workpiece by rotating the workpiece relative to the carrier,
A suspension plate adapted to move in the vertical direction by the upper surface plate elevating part;
A first pulley group pivotally supported by a plurality of rotating shafts protruding from the side surface of the suspension plate;
A support member fixed to the upper surface plate;
A second pulley group supported by a plurality of rotating shafts protruding from the side surface of the support member;
An endless shape that is stretched between a pulley that constitutes the first pulley group and a pulley that constitutes the second pulley group so as to divide and vertically support the vertical load of the upper surface plate With wire rope,
A tension sensor for measuring the tension of the wire rope;
It is provided with.

Moreover, the double-side polishing apparatus according to claim 2 of the present invention includes:
In the double-side polishing apparatus according to claim 1,
A signal processing unit to which the upper platen lifting unit and the tension sensor are connected together;
This signal processor
The load of the upper surface plate stretched from the suspension plate via the pulleys of the first and second pulley groups is detected from the input data of the tension sensor, and compared with a preset workpiece processing pressure value, etc. And outputting a control signal corresponding to the difference to the pressure control valve for controlling the fluid pressure supplied to the lifting cylinder of the upper platen lifting and lowering section,
It is characterized by.

Moreover, the double-side polishing apparatus according to claim 3 of the present invention includes:
In the double-side polishing apparatus according to claim 1 or 2,
A vibration detector for detecting vibration of the upper surface plate is provided.

Moreover, the double-side polishing apparatus according to claim 4 of the present invention includes:
In the double-side polishing apparatus according to claim 3,
A signal processing unit to which the upper platen lifting unit and the vibration detector are connected together;
This signal processor
Input vibration data from the vibration detector, determine whether or not a preset vibration level threshold has been exceeded, and if the vibration level threshold is exceeded, immediately stop machining the workpiece and Controlling to ascend,
It is characterized by.

A double-side polishing apparatus according to claim 5 of the present invention is
In the double-side polishing apparatus according to any one of claims 1 to 4,
In order to detect the distance from the upper surface plate to the upper surface of the lower surface plate or the distance from the upper surface of the carrier,
An inner circumference side clearance measurement sensor disposed on the inner circumference side of the upper surface plate and immediately above an arbitrary position of the carrier at the start of machining;
An outer peripheral side gap measuring sensor disposed on the outer peripheral side of the upper surface plate and immediately above an arbitrary position of the carrier at the start of processing;
It is characterized by providing.

A double-side polishing apparatus according to claim 6 of the present invention
In the double-side polishing apparatus according to claim 5,
A signal processing unit to which the inner circumferential side gap measurement sensor and the outer circumferential side gap measurement sensor are connected together;
This signal processor
In the step of lowering the upper surface plate immediately before the start of machining to the workpiece and the lower surface plate,
When the input data of the tension sensor reaches a preset landing load, the lowering of the upper surface plate is stopped, and the carrier upper surface from the inner circumference side gap measurement sensor and the outer circumference side gap measurement sensor at this time is stopped. Each of the gap data, and when at least one of the gap data exceeds a preset threshold, it is judged as abnormal, the machining process is stopped and the upper surface plate is raised,
In the workpiece machining process,
The gap data between the upper and lower surface plates from the inner circumference side gap measurement sensor and the outer circumference side gap measurement sensor, that is, the workpiece thickness data, are respectively input to obtain an average value thereof, and this value reaches a preset processing target thickness. Control whether to raise the upper surface plate by stopping the machining of the workpiece when the target thickness is reached,
It is characterized by.

The processing method of the double-side polishing apparatus according to claim 7 of the present invention is:
In the double-side polishing apparatus according to claim 6, in the operation process when landing on the upper surface plate immediately before the start of processing,
The carrier rotation start time is set in advance so that the carrier rotates during a predetermined amount around the original central axis when the upper surface plate descends at a slow speed and places on the work surface. And the amount of rotation of the carrier is (1 / number of workpieces) × N (where N is an integer),
It is characterized by.

  According to the present invention, both sides of a three-way planetary gear system that realizes automation of a polishing process in addition to an increase in size of a device and a high processing quality (thickness accuracy, flatness) in a trade-off relationship. A polishing apparatus and a processing method can be provided.

It is a perspective view of the principal part of the 3-way type double-side polish apparatus of the form for implementing this invention. It is sectional drawing of the principal part of the 3-way type double-side polish apparatus of the form for implementing this invention. It is a top view of the carrier of a double-side polish apparatus. It is a circuit block diagram of a double-side polishing apparatus. It is explanatory drawing of the landing process of an upper surface plate. It is a flowchart of the landing process of an upper surface plate. It is explanatory drawing of the relative speed of an upper surface plate, a lower surface plate, and a carrier. It is a perspective view of the principal part of the 3-way type double-side polish apparatus of the other form for implementing this invention. It is sectional drawing of the principal part of the 3-way type double-side polish apparatus of the other form for implementing this invention. It is a circuit block diagram of a double-side polishing apparatus. It is sectional drawing of the principal part of the 3-way type double-side polish apparatus of the form for implementing this invention. It is a top view of the carrier of a double-side polish apparatus. It is a circuit block diagram of a double-side polishing apparatus. It is a flowchart of the landing process of an upper surface plate. It is a perspective view of the principal part of the 4-way type double-side polish apparatus of a prior art. It is sectional drawing of the principal part of the 4-way type double-side polish apparatus of a prior art.

  Then, the form for implementing this invention is demonstrated below, referring a figure. First, the overall structure of the double-side polishing apparatus 100 will be described with reference to FIGS. Reference numeral 1 denotes a lower surface plate which is rotated by a lower surface plate rotation driving unit (not shown), 2 denotes a plurality of carriers arranged radially on the lower surface plate 1, 3 denotes meshing with a tooth surface on the outer periphery of the carrier 2, and an inner side not shown An internal gear 4 rotated by a gear rotation drive unit, 4 meshes with teeth on the outer periphery of the carrier 2, and a sun gear rotated by a sun gear rotation drive unit (not shown), 5 is a work holding hole 2a formed in the carrier 2. A plurality of workpieces that are mounted on and lapped or polished, 6 is an upper surface plate, 7 is a pulley that constitutes a first pulley group, and 8 is an example of a support member of the present invention and is a ring that is formed in an annular shape , 9 is a pulley constituting the second pulley group, 10 is a pentagonal suspension plate, 11 is a bearing disposed at the center of the suspension plate 10, 12 is a wire rope spanned between the pulleys 7 and 9, 13 Is the top plate 14 is a stopper, 14 is a stopper, 15 is a rod tip of an air cylinder (a specific example of the upper platen raising / lowering part of the present invention) supported by a bearing 11, 16 is a bracket, and 17 is a tension sensor. . Hereinafter, specific examples will be described.

  A concentric ring 8 is fixed to a position near the inner periphery of the upper surface of the upper surface plate 6 so as to be integrated with the upper surface plate 6, and five pulleys 7 are horizontally disposed on the outer peripheral surface of the ring 8. Are attached to a rotating shaft at equal intervals. It is attached every 72 ° when viewed from above. Above the ring 8, a pentagonal suspension plate 10 is rotatably supported by a rod tip 15 via a bearing 11.

  A total of ten pulleys 9 are attached to the horizontal rotating shaft on the outer peripheral surface of the suspension plate 10, two on each side. Between the pulley 7 of the ring 8 and the pulley 9 of the suspension plate 10, a wire rope 12 connected between both ends to be endless is stretched, and the ring 8 and the upper surface plate 6 are stretched by the wire rope 12. Is supported by the suspension plate 10 with an equal force. In this embodiment, two pulleys 9 and one pulley 7 are alternately wound and are suspended at 10 points in the vertical direction by the wire rope 12.

A tension sensor 17 is provided at one location of the wire rope 12. The tension sensor 17 measures the wire tension. The wire rope 12 is passed between the pulley 7 and the pulley 9 at 10 places, and the upper surface plate 6 is suspended. In other words, a tension of 1/10 of the weight of the upper surface plate 6 is applied to the wire rope 12 between the pulley 7 and the pulley 9 at one place. For this reason, the wire tension measured by the tension sensor 17 is also measured as a tension that is 1/10 of the weight of the upper surface plate 6. The load cell 112 of the prior art described with reference to FIGS. 15 and 16 needs to measure all the weights of the suspension plate 107, the connecting shaft 106, the upper surface plate 109, etc. It was necessary to install a measuring instrument, and it was very expensive, including structural changes for installation. In addition, when a large-capacity load cell is installed on such a support shaft, it is easy to measure the load in the rod axis direction, but there is a problem that it is not possible to accurately detect an offset load acting on an upper surface plate having a large area. is there.
In the measurement method using the wire tension meter according to the present invention, a tension meter having a capacity of 1/10 or less can be used in this example, and it can be easily installed, so that it can be installed at a low cost without any significant mechanical design change. it can. In addition, since the structure is attached in the middle of the endless wire, the uneven load of the upper surface plate can be measured as the wire tension only in the wire longitudinal direction.

In the case of a large polishing apparatus, the number of pulleys is greatly increased. For example, when the wire rope 12 is supported at 64 points (: M), the tension sensor is applied to the load of the upper surface plate 6 = 3000 kg. The load acting on the pressure = 3000 × 1/64 (: M) ≈47 kg, and an inexpensive tension sensor 17 having a smaller measurement range can be selected. In addition, the error is reduced and the measurement accuracy can be improved. This number M is a design matter and can be supported at M locations.
Then, the load of the upper surface plate 6 stretched from the suspension plate 10 via the pulleys 7 and 9 of the first and second pulley groups is detected from the input data of the tension sensor 17, and a preset workpiece processing pressure value is obtained. And a control signal according to the difference between them is output to the pressure control valve that controls the fluid pressure supplied to the lifting cylinder of the upper surface plate lifting and lowering section 19 to set the surface pressure that acts on the workpiece. Can be controlled on the street.

  A plurality (two in the present embodiment, for example) of pins 13 are erected at positions near the outer periphery of the upper surface of the upper surface plate 6 and facing each other. Further, a stopper 14 is pivotally supported on a bracket 16 that is integrally attached to a board body (not shown), and the stopper 14 is configured to be tilted with respect to the bracket 16. By lowering the tip of the stopper 14 to the upper side of the upper surface plate 6, the stopper 14 comes into contact with the side surface of the pin 13. A plurality of such anti-rotation pins 13 are provided so as to protrude from a position near the outer periphery of the upper surface of the upper surface plate 6. Further, the same number of stoppers 14 are provided, and are configured to stop the rotation of the upper surface plate 6 by being supported on the side of the panel body and coming into contact with the side surface of the non-rotating pin 13.

In this manner, the upper surface plate 6 is suspended at M positions at equal intervals in the rotation direction by the wire rope 12, so that the upper surface plate 6 is stabilized at a position parallel to the horizontal plane.
In addition to supporting the ring 8 and the suspension plate 10 with the wire rope 12, the operation is restricted so that the upper surface plate 6 moves only in the vertical direction. It is good also as a form which maintains parallel with respect to the lower surface plate 1 reliably.

  As shown in FIG. 3, a plurality of (five in this embodiment) carriers 2 are meshed with the internal gear 3 and the sun gear 4 and are equally divided on the upper surface of the annular lower surface plate 1. A plurality of workpieces 5 are mounted in the workpiece holding holes 2 a formed in the carrier 2. The carrier 2 is provided with a carrier notch 2b, a carrier number, a holding hole number, and the like.

  When polishing the workpiece 2, the inner gear 3 and the sun gear 4 are rotated at the same time as the lower surface plate 1 is rotated while supplying rinse and slurry from a supply hole (not shown) provided in the upper surface plate 6. As a result, the carrier 2 with the work 5 held between the lower surface plate 1 and the upper surface plate 6 revolves while rotating, and both surfaces of the work 5 are polished.

  The rotation of the lower surface plate 1, the internal gear 3, and the sun gear 4 is controlled by the lower surface plate rotation drive unit, the internal gear rotation drive unit, and the sun gear rotation drive unit, respectively. Perform proper polishing. Furthermore, in an automated polishing machine, a servomotor and its control device are mounted so that the internal gear rotation drive unit and the sun gear rotation drive unit can perform positioning control. The term “polishing” as used herein is a general term for abrasive processing such as lapping and polishing including grinding. The double-side polishing apparatus shown in FIG. 1 and FIG. 2 is composed of three movement elements including the rotation of the lower platen 1, the rotation of the carrier 2, and the revolution of the carrier 2. It is called.

  The circuit block is as shown in FIG. The tension sensor 17 is connected to the signal processing unit 18, and the signal processing unit 18 is connected to the upper surface plate lifting / lowering unit 19. The upper surface plate elevating unit 19 is specifically a drive unit using an air cylinder, but pressure control for controlling the fluid pressure supplied to the elevating cylinder of the upper surface plate elevating unit by the control signal from the signal processing unit 18. By outputting to the valve, the upper surface plate 6 is moved up and down, and the surface pressure on the work is kept constant. The signal processing unit 18 also controls the lower surface plate rotation driving unit, the internal gear rotation driving unit, and the sun gear rotation driving unit, and the rinsing and slurry supply (not shown). Specific control will be described later.

Next, a specific processing operation will be described. First, a loading operation (loading operation) for loading a workpiece onto each carrier is performed.
As shown in FIG. 3, a plurality of workpieces 5 are loaded into the workpiece holding holes 2 a drilled in the carrier 2. In the case of automation, this loading operation is automatically performed by a work handling robot or the like.

  Subsequently, a landing process for placing the upper surface plate on the workpiece is performed. In this landing process, it is necessary to minimize damage to the work 5 sandwiched at the time of landing and to avoid damage to the work 5 in a normal work attachment state. For example, there is a case where stress is applied to the workpiece 5 when there is a slurry lump adhering to the upper surface plate 6. Therefore, it is important to place the carrier so as not to generate a local surface pressure increase portion while crushing the slurry lump even if there is a slurry lump, by gradually putting the carrier while rotating the carrier. is there. Furthermore, it is necessary to set the landing load of the upper surface plate 6 as low as possible. Although it is possible to rotate the carrier 2 around the center axis of the platen as at the start of general machining, when the movement amount of the workpiece 5 is increased in this way, the workpiece 5 becomes the workpiece of the carrier 2. If the workpiece 5 is greatly disengaged from the holding hole 2a, or the workpiece 5 is damaged and scattered on the lower surface plate 1 when the upper surface plate 6 is mounted, the subsequent restoration work becomes very complicated. . This normal landing process will be described with reference to FIGS. This step is performed by the signal processing unit 18. It is assumed that an appropriate landing load is set in advance. For example, the landing load is set to a sufficiently small value (300 N to 500 N) by the tension sensor 17. As shown in FIG. 6, the signal processing unit 18 starts normal lowering of the upper surface plate 6 (step S1) and functions as a reference speed lowering means for lowering the upper surface plate 6 at the reference speed (step S2). Then, the signal processing unit 18 determines whether or not the speed change position has been reached (step S3). If the speed change position has been reached, measurement of the landing time is started (step S4). Whether or not the speed change position has been reached may be detected by various sensors such as limit switches.

  The signal processing unit 18 starts a timer for the carrier rotation start time (step S5). This carrier rotation start time is calculated by the following equation, for example.

[Equation 1]
Carrier rotation start time = previous landing time-1/2 carrier rotation time

  This is to set the carrier rotation start timing in advance so that the carrier 2 rotates and rotates during the rotation immediately before landing. Basically, the rotation time x 1/2 from the previous record. It was set to land at. Note that 1/2 of the coefficient is not a particularly limited value, and it is sufficient that the upper surface plate 6 is surely placed during the rotation operation of the carrier 2.

  The point is that the position of the sensor installed on the upper surface plate 6 around the center axis of the carrier 2 is always the same as the amount of rotation of the carrier 2 (relative positional relationship with the adjacent work holding hole 2a and carrier notch 2b). Is to be the same). As described above, the carrier 5 is provided with a carrier notch 2b, a carrier number, a holding hole number, and the like in addition to the work holding hole 2a, and a sensor is provided in these carrier notches 2b (or the vicinity thereof). If the distance is lowered and measured, accurate distance data cannot be obtained. For this reason, for example, a carrier for holding four workpieces is set to 1/4 rotation or 1/2 rotation. Although it is necessary to perform measurement at the same position in the circumferential direction so as not to be affected by the work holding hole 2a and the carrier notch 2b of the carrier 2, the upper surface plate 6 is used in the 3-way double-side polishing apparatus of the present invention. Has the advantage that the sensor position is always constant because of non-rotation.

  The signal processing unit 18 functions as a slow speed lowering means for lowering the upper surface plate 6 at a slow speed slower than the reference speed (step S6), and drops rinse or slurry (step S7). Then, the signal processing unit 18 determines whether or not the timer has reached the carrier rotation start time (step S8), and performs a slow speed drop of the upper surface plate and dripping of rinse and slurry until the carrier rotation start time is reached. Shall continue.

  The signal processing unit 18 functions as carrier rotation means for driving the internal gear rotation driving unit and the sun gear rotation driving unit so as to start the carrier rotation when the carrier rotation start time is reached (step S9). For example, the internal gear 3 is rotated at an angular velocity ω and the sun gear 4 is rotated at an angular velocity −ω to make each carrier rotate without revolving. The purpose of this carrier rotation is to disperse the load acting on the workpiece 5 when the upper surface plate is placed, and to avoid local damage due to slurry lump.

  The signal processing unit 18 further lowers the upper surface plate 6 at a slow speed, and functions as a determination unit that determines whether or not the wire tension data from the tension sensor 17 has reached a preset upper surface platen load. (Step S10). At this time, according to the structure of the present invention, since the upper surface plate 6 has the function of cushioning the stretched wire and the posture following function, it is possible to mitigate the generation of an impact load at the time of landing. At the same time, a relatively small contact reaction force can be reflected in the wire tension for measurement.

  The signal processing unit 18, together with the suspension plate 10, determines that the upper surface plate 6 is in contact with the workpiece 5 at an optimum pressure (that is, has landed) when the tension data falls below a predetermined value. It functions as an upper surface plate lowering stop means for driving the upper surface plate elevating part so as to stop the lowering of the upper surface plate (step S11). In this case, the load condition of the upper surface plate 6 with respect to the workpiece 5 is the same as the preset landing load, and the load on the workpiece 5 is suppressed to a minimum and is in slight contact with the upper surface plate 6. Yes. The signal processor 18 ends the landing time measurement (step S12). This landing time is used in the calculation of the next carrier rotation start time. In general, there are many fluctuation factors such as the characteristics of the lifting cylinder (sliding friction, etc.), the supply speed of the pressurized fluid to the lifting cylinder, or the change in the weight due to the wear of the surface plate. It is necessary to do.

  The signal processing unit 18 controls the internal gear rotation driving unit and the sun gear rotation driving unit so as to stop the carrier rotation, and determines whether or not the carrier rotation has ended (step S13). For example, it can be easily determined from outputs of an encoder, a speed meter, and the like included in the internal gear rotation drive unit and the sun gear rotation drive unit.

When the signal processing unit 18 determines that the carrier rotation has ended, the signal processing unit 18 stops the rinsing and the dripping of the slurry (step S14).
Subsequently, the distance to the upper surface of each carrier is measured by the inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 respectively, and when any measured value exceeds the reference value, “work clamping” = “ It is determined that the workpiece is poorly loaded, and an abnormal signal is output from the signal processing unit 18 to the external control device or the display device, and the upper surface plate 6 is raised to a predetermined ascent position. If any measured value is below the reference value, the preparation for machining operation is completed.

Subsequently, double-side processing is performed.
Three axes of the internal gear 3, the sun gear 4, and the lower surface plate 1 excluding the upper surface plate 6 by driving the lower surface plate rotation drive unit, the internal gear rotation drive unit, and the sun gear rotation drive unit (all not shown). Are rotated at a predetermined rotational speed, so that the carrier 2 performs a planetary motion, and the upper surface plate 6 and the lower surface plate 1 that press the upper and lower surfaces of the work 5 rotate relative to the work 5. As a result, the upper and lower surfaces of the work 5 are polished.

  As the carrier 2 revolves, force is applied from the work 5 to the upper surface plate 6 to rotate the upper surface plate 6 in the same direction, but the rotation is prevented because the pin 13 is in contact with the stopper 14. Then, the upper surface plate 6 is held in a stopped state. In actual polishing, only the lower surface plate 1 is rotated without rotating the upper surface plate 6 while supplying the rinse or slurry by dropping from a supply hole (not shown) provided in the upper surface plate 6. At the same time, the carrier 2 is rotated and revolved by rotating the internal gear 3 and the sun gear 4 at different angular velocities.

  In the present invention, the carrier 2 on which the work 5 is mounted moves on the planetary surface while being sandwiched between the lower surface plate 1 and the upper surface plate 6, whereby both surfaces of the work 5 are polished. That is, in this embodiment, the workpiece 5 is processed by a combination of three movement elements including the rotation of the lower surface plate 1, the rotation of the carrier 2, and the revolution of the carrier 2, and both surfaces are polished by a 3-way method. In this embodiment, since the upper surface plate 6 is not rotated, it is not necessary to consider centrifugal force and the like, and thus the upper surface plate 6 can be suspended. In this way, the lower surface plate 1 is rotated while the upper surface plate 6 is not rotated, and the influence of the moment of inertia generated by the rotational driving of the upper surface plate 6 is eliminated, so that the natural fall by the gravity of the upper surface plate, that is, the lower surface plate is achieved. The purpose is to facilitate the tracking to 1.

  In the middle of such double-side polishing, when the workpiece 5 is polished and the upper surface level of the workpiece 5 is lowered, the wire rope 13 is extended and the upper surface plate 6 is naturally lowered by gravity. The lower surface of the upper surface plate 6 closely follows the upper surface of the work 5 and comes into close contact therewith. In this case, the wire tension data from the tension sensor 17 is increased, but the signal processing unit 18 lowers the upper platen 6 until the wire tension data reaches a predetermined value by the upper platen lifting / lowering unit 19, and the wire tension data is predetermined. When the value is reached, the upper surface plate elevating part 19 is stopped to maintain a predetermined surface pressure. As a result, it is possible to perform double-side processing at a surface pressure that is always optimal for the workpiece 5. In this way, by suspending the upper surface plate 6 with the wire rope 12, the followability of the upper surface plate 6 with respect to the surface of the work 5 is improved so that the upper surface plate 6 is always parallel to the lower surface plate 1. Yes.

  In this embodiment, the rotation of the upper surface plate 6 is 0 because the rotation of the upper surface plate 6 is stopped by the contact of the pin 13 and the stopper 14, but the rotation speed of the lower surface plate 1 and the revolution of the carrier 2 are rotated. By adjusting the speed, machining equivalent to that of a conventional 4-way parallel plane machining machine can be realized. Such speed adjustment will be described. FIG. 7 is an explanatory diagram for explaining the speed control of the lower surface plate 1, the upper surface plate 6 and the carrier 2. The description is simplified without considering the rotation of the carrier 2.

  For example, when the relative speed between the revolution speed of the carrier 2 and the rotational speed of the lower surface plate 1 and the relative speed between the revolution speed of the carrier 2 and the rotational speed of the upper surface plate 6 are made equal, For example, FIG. 7A shows a double-side polishing apparatus.

  That is, if the upper surface plate 6 is rotated counterclockwise at an angular velocity of −0.5ω and the carrier 2 is revolved clockwise at an angular velocity of 0.5ω, If the upper surface contacts the upper surface plate 6 at an angular velocity ω, similarly, the lower surface plate 1 is rotated clockwise at an angular velocity of 1.5ω and the carrier 2 is revolved clockwise at an angular velocity of 0.5ω. When the workpiece 5 is used as a reference, the lower surface of the workpiece 5 comes into contact with the lower surface plate 1 at an angular velocity −ω.

  In order to achieve the same processing as the 4-way double-side polishing apparatus using the 3-way double-side polishing apparatus of this embodiment, for example, as shown in FIG. If the carrier 2 is revolved clockwise at an angular speed ω with respect to the board 6, the upper surface of the work 5 comes into contact with the upper surface plate 6 at the angular speed ω when the workpiece 5 is used as a reference. If the workpiece 2 is rotated clockwise at the angular velocity 2ω and the carrier 2 is revolved clockwise at the angular velocity ω, the lower surface of the workpiece 5 contacts the lower surface plate 1 at the angular velocity −ω.

  As described above, with respect to the relative speed of the workpiece 5 with respect to the upper surface plate 6 and the lower surface plate 1, the same effect as that of the conventional 4-way type parallel flat surface processing machine can be obtained even in the lower surface plate 1, It can be obtained by adjusting the rotational speeds of the internal gear 3 and the sun gear 4.

  Thereby, in order to improve the followability to the lower surface plate 1 of the upper surface plate 6 and to eliminate the influence of the moment of inertia caused by the rotational drive of the upper surface plate, the upper surface plate 6 is not rotated while the lower surface plate 1 is rotated. 15 and 16 of the prior art to avoid a situation in which the dynamic frictional resistance between the keyway 110a of the drive shaft 110 and the drive key 111 becomes large, and to prevent natural movement due to gravity of the upper surface plate. Make descent easier.

  In this way, in the double-side polishing apparatus 100, the sun gear, so that the relative speed of the upper surface plate and the lower surface plate that are in contact with the upper and lower surfaces of the carrier is substantially the same with the upper surface plate stopped. The rotational speeds of the internal gear and the lower surface plate can be controlled.

Further, the signal processing unit 18 that can be used for detecting foreign matter other than the landing process inputs the tension data from the tension sensor 17, the tension data from the tension sensor 17 decreases, and the predetermined data is obtained from the tension data. When it functions as a tension determination means that determines whether the difference value becomes negative by pulling the machining pressure value, and it is determined that an excessive load is applied between the upper surface plate 6 and the workpiece 5 because the difference value becomes negative The upper platen lifting / lowering unit 17 is driven so as to raise the upper platen 6 together with the suspension plate 10 to function as an upper platen lifting / lowering means at the time of excessive load. With such a configuration, even if there is an unexpected foreign object, it can be detected by a change in tension. If such a function is added, safety can be further improved.

  Such a double-side polishing apparatus 100 of the present invention has the following advantages. For purposes of explanation, the present invention is compared with the prior art. In the conventional technology, the internal pressure value of the air cylinder for lifting is detected and controlled, so the surface pressure that actually acts is not measured, so feed-forward control is performed, and high-precision surface pressure control is impossible. there were.

In addition, the conventional technology has a limit in accuracy because it does not measure the actual surface pressure.
In the prior art, at the level of the landing load applied to the workpiece (about several tens of kgf, that is, about several hundred N), the landing load is controlled to a desired value due to the influence of mechanical loss such as the friction force of the cylinder rod in the air cylinder. It was difficult.

  On the other hand, according to the present invention, a system for controlling the surface pressure applied to the workpiece 5 by installing the tension sensor 17 in the middle of the endless wire rope 12 hanging from the suspension plate 10 of the upper surface plate to the upper surface plate 6. Can be configured as feedback control, so that highly accurate surface pressure control is possible.

  Further, according to the present invention, since the upper surface plate follows the workpiece surface by the 3-way method, a net suspension load acts on the suspension wire, and the surface pressure is accurately measured and controlled. Is possible. That is, it is a structure that is not subject to disturbance such as moment load due to the contact of the upper surface plate.

  In addition, according to the present invention, only the load of the ring body 8 and the upper surface plate 6 that affects the surface pressure is measured, so that it is possible to calculate a highly accurate surface pressure from the measured value, and the highly accurate surface pressure control. It can be performed.

  Further, according to the present invention, the maximum load acting on the wire = the weight of the upper surface plate / the number N of wires passed up and down, so that a small capacity and inexpensive tension sensor can be used. In addition, since the installation is easy, maintenance inspection and replacement work are very easy.

  Next, another embodiment will be described with reference to FIG. 8, FIG. 9, and FIG. The double-side polishing apparatus 100 ′ of this embodiment is different from the double-side polishing apparatus 100 described above with reference to FIGS. 1 to 7 only in that a vibration detector 20 is additionally mounted. Therefore, the vibration detector 20 will be described in detail, and the other configurations are the same, and thus the same reference numerals are given and redundant descriptions are omitted. Hereinafter, the vibration detector 20 will be described.

  As is clear from FIGS. 8 and 9, the vibration detector 20 is provided in contact with the upper surface plate 6 and detects vibration applied to the upper surface plate 6. The vibration detector 20 is connected to the signal processing unit 18 as shown in FIG. For example, the signal processing unit 18 functions as an abnormal vibration determination unit that inputs vibration data from the vibration detector 20 and determines whether or not a predetermined vibration level threshold is exceeded, and exceeds the vibration level threshold. In this case, the upper surface plate lifting / lowering unit 19 is controlled to stop the machining of the workpiece and raise the upper surface plate immediately, and the lower surface plate 1 and each gear are decelerated to stop and then abnormal vibration is notified. It functions as an upper and lower surface plate lifting means. In vibration determination, more specifically, a threshold value is determined in advance as a predetermined level from actual vibration intensity data, and a vibration detection signal that detects vibration from the vibration detector 20 is constantly input to detect vibration that exceeds a predetermined level. What is necessary is just to judge that there was abnormal vibration when the signal was input.

  In particular, abnormal vibrations that occur on the upper surface plate 6 (fixed part) in the machining process are detected, and abnormalities in the workpiece and abnormalities that occur in the apparatus itself are detected. Generally called “crash detection”. In the 3-way method, the suspended upper surface plate 6 does not rotate and is imitated by applying a uniform surface pressure to the work surface, and since there is no constraint from the upper surface, minute vibrations are measured with high sensitivity. can do. Incidentally, in the 4-way double-side polishing apparatus as described with reference to FIGS. 15 and 16, it is difficult to detect minute vibrations because the upper surface plate has rotational inertia.

In particular, after the process of FIG. 6, the distance to the upper surface of each carrier is measured by the inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22, and if any measured value exceeds the reference value, In the process of determining that “work jamming” = “workpiece loading failure”, if “work jamming” cannot be detected, the abnormal vibration judgment means can perform “crash detection” in the initial stage of the machining process. Therefore, it can be positioned as backup means for the abnormal loading detection means.
In the unlikely event that any object hits the upper platen 6, the suspended upper platen will vibrate, and if machining continues, machining accuracy will deteriorate. What is necessary is just to process.

In addition, when a foreign object is caught between the upper and lower surface plates and the workpiece during processing and vibration occurs, the tension of the tension sensor 17 also decreases momentarily, so that the signal processing unit 18 generates vibration and lowers the tension data. May be determined to be due to foreign matter and the above-described processing may be performed.
According to such a double-side polishing apparatus 100 ′ of this embodiment, convenience is further enhanced.

  Next, another embodiment will be described with reference to FIGS. 11, 12, 13, and 14. FIG. The double-side polishing apparatus 100 ″ of this embodiment is equipped with a vibration detector 20, an inner peripheral side gap measuring sensor 21, and an outer peripheral side gap measuring sensor 22 as compared with the double-side polishing apparatus 100 described above with reference to FIGS. Therefore, the inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 will be described in detail, and the other configurations are the same, so that the same reference numerals are given and redundant description is omitted. Hereinafter, the inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 will be described.

  The inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 are specifically non-contact sensors such as an eddy current sensor, and as shown in FIG. 11, FIG. 12, FIG. 13, and FIG. It is built in the panel 6 and detects the distance from the inner circumferential side gap measuring sensor 21 and the outer circumferential side gap measuring sensor 22 to the lower surface to be detected. The inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 are connected to the signal processing unit 18 as shown in FIG.

  As shown in FIG. 12, the inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 according to the present invention are installed on the inner circumference side and the outer circumference side at substantially diagonal positions with respect to the central axis of the upper surface plate 6. The signal processing unit 18 continuously measures the distance data from the upper surface plate 6 to the upper surface of the lower surface plate 1 during processing, and sets the workpiece thickness as an average value of the distance data. In the prior art, one such sensor is arranged, and the workpiece thickness is managed based on the data obtained from this single sensor. In addition to reducing the effects of changes in shape (thinning due to wear, thermal deformation, etc.) on the inner and outer circumferences of large surface upper and lower surface plates in the grinding machine and the influence of inclusions between the work surface and each surface plate Measurement accuracy can be improved.

  Further, as shown in FIG. 12, the inner circumference side gap measuring sensor 21 of the present invention is arranged on the inner circumference side of the upper surface plate 6 and immediately above an arbitrary position of the carrier 2 at the start of processing. As shown in FIG. 12, the side gap measuring sensor 22 is arranged on the outer peripheral side of the upper surface plate 6 and immediately above an arbitrary position of the carrier 2 at the start of machining. Then, after the series of steps shown in FIG. 6 is completed after the work loading, the distance data from the upper surface plate 6 to the upper surface of the carrier 2 is measured by the inner circumferential side gap measuring sensor 21 and the outer circumferential side gap measuring sensor 22, respectively. If any of the distance data exceeds a predetermined value, it is determined that “work is caught” = “work loading failure”, and an abnormal signal is output from the signal processing unit 18 to the external control device or display device. Raise the board to a predetermined raised position. If any measured value is below the reference value, the preparation for machining operation is completed. If the machining is performed as it is with the workpiece sandwiched, a crash occurs, which damages the carrier, workpiece, surface plate, and the like, resulting in significant damage to the equipment.

  14 is performed in the same manner as steps S1 to S18 in FIG. 14. Steps S1 to S14 in FIG. 14 are the same as steps S1 to S14 in FIG. S1 to S14 are the same step, and redundant description is omitted.

Subsequent to steps S1 to S14, loading failure detection is performed in steps S15 to S18.
The signal processing unit 18 inputs the gap data from the inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 (step S15), and determines whether any one of the gap data exceeds the threshold data obtained in advance. It functions as a gap determining means for determining (step S16). When the gap data is smaller than the predetermined threshold data, it is determined that the workpiece is not pinched and the machining operation preparation is completed. On the other hand, when the gap data is larger than the predetermined threshold data and the work 5 is removed from the carrier holding hole 2a and it is determined that the work is not loaded correctly, the upper platen lifting / lowering unit is configured to raise the upper platen 6 together with the suspension plate 10 immediately. The upper platen lifting / lowering means for loading failure that drives 19 (step S17), the signal processing unit 18 controls the speaker and the display unit so as to notify the occurrence of an error (step S18), and then waits for a recovery operation. It becomes.

In the workpiece machining process, the gap data between the upper and lower surface plates, that is, the workpiece thickness data from the inner circumference side gap measurement sensor 21 and the outer circumference side gap measurement sensor 22 are respectively inputted to obtain an average value thereof. It is determined whether or not the set machining target thickness is reached, and when the target thickness is reached, the workpiece machining is stopped and the upper surface plate 6 is controlled to rise. In this way, the workpiece thickness can be brought close to the target value. The double-side polishing apparatus 100 "is such.
As described above, the inner circumferential side gap measuring sensor 21 and the outer circumferential side gap measuring sensor 22 which are workpiece thickness measuring means during machining can be used as they are to detect the workpiece loading state at the machining preparation stage. Since it can be used, there is no need to install any additional equipment. Further, by limiting the installation position of each sensor to an arbitrary position, it is possible to play a role suitable for each purpose. Furthermore, the vibration detection means is also positioned as a backup means in the event that the workpiece loading state detection means cannot be detected, and it is possible to avoid a great influence on the equipment due to the occurrence of a crash.

  Further, when a foreign object is sandwiched between the upper and lower surface plates and the workpiece during processing, the tension of the tension sensor 17 is instantaneously reduced, so that the signal processing unit simultaneously reduces the distance data and the tension data. When it is detected together, it may be determined that it is due to a foreign substance, and the above processing may be performed.

In the present embodiment, the vibration detector 20 may be removed, and measurement by the tension sensor 17 and measurement by the inner circumferential side gap measurement sensor 21 and the outer circumferential side gap measurement sensor 22 may be performed.
According to such a double-side polishing apparatus 100 ″ of this embodiment, convenience is further enhanced.

  Further, in the structure of the prior art 4-way double-side polishing apparatus described with reference to FIGS. 15 and 16, there is a concern that impact stress at the time of landing may be given to the workpiece, and further, the load cell has an impact load. Since the moment load acts, there was a problem that the landing load could not be controlled with high precision, but in the structure of the 3-way double-side polishing apparatus of the present invention, the suspension wire has the role of a spring. These impact loads do not occur, and according to the configuration of the present invention, the surface plate can be uniformly and accurately controlled with respect to the application of surface pressure to the workpiece in the machining process, so that the workpiece quality is improved. be able to.

  In addition, the operation at the time of landing is performed by applying the relative movement between the upper surface plate and the work (carrier) and by placing the rinse or slurry while supplying the work stress. It also reduces the work stress at the start of machining.

  The double-side polishing apparatus and processing method according to the present invention as described above are suitable for high-precision planar processing such as lapping and polishing.

100, 100 ', 100 ": Double-side polishing apparatus 1: Lower surface plate 2: Carrier 2a: Workpiece holding hole 2b: Carrier notch 3: Internal gear 4: Sun gear 5: Work 6: Upper surface plate 7: Pulley 8: Ring 9: Pulley 10: Suspension plate 11: Bearing 12: Wire rope 13: Pin 14: Stopper 15: Rod tip 16: Bracket 17: Tension sensor 18: Signal processing unit 19: Upper platen lifting / lowering unit

Claims (7)

The upper surface plate is moved up and down by the upper surface plate elevating unit, the lower surface plate is rotated by the lower surface plate rotation drive unit, the internal gear is rotated by the internal gear rotation drive unit, and the sun gear is rotated by the sun gear rotation drive unit. A plurality of carriers having tooth surfaces on the outer periphery and a plurality of workpiece holding holes formed in the rotational direction are meshed between a sun gear and an internal gear arranged in a horizontal plane. With the front and back surfaces of the workpiece inserted into the workpiece holding hole sandwiched between the lower surface plate and the upper surface plate, the sun gear and the internal gear are rotated to planetarily move the carrier, and the lower surface plate In a three-way planetary gear type double-side polishing apparatus that wraps or polishes a workpiece by rotating the workpiece relative to the carrier,
A suspension plate adapted to move in the vertical direction by the upper surface plate elevating part;
A first pulley group pivotally supported by a plurality of rotating shafts protruding from the side surface of the suspension plate;
A support member fixed to the upper surface plate;
A second pulley group supported by a plurality of rotating shafts protruding from the side surface of the support member;
An endless shape stretched between the pulleys constituting the first pulley group and the pulleys constituting the second pulley group so as to divide and vertically support the vertical load of the upper surface plate With wire rope,
A tension sensor for measuring the tension of the wire rope;
A double-side polishing apparatus comprising: In the double-side polishing apparatus according to claim 1,
A signal processing unit to which the upper platen lifting unit and the tension sensor are connected together;
This signal processor
The load of the upper surface plate stretched from the suspension plate via the pulleys of the first and second pulley groups is detected from the input data of the tension sensor, and compared with a preset workpiece processing pressure value. Outputting a control signal corresponding to the difference between them to a pressure control valve for controlling a fluid pressure supplied to the elevating cylinder of the upper surface plate elevating unit,
A double-side polishing apparatus characterized by In the double-side polishing apparatus according to claim 1 or 2,
A double-side polishing apparatus comprising a vibration detector for detecting vibration of the upper surface plate. In the double-side polishing apparatus according to claim 3,
A signal processing unit to which the upper platen lifting unit and the vibration detector are connected together;
This signal processor
Input vibration data from the vibration detector, determine whether or not a preset vibration level threshold has been exceeded, and if the vibration level threshold is exceeded, immediately stop machining the workpiece and Controlling to ascend,
A double-side polishing apparatus characterized by In the double-side polishing apparatus according to any one of claims 1 to 4,
To detect the distance to the upper surface of each lower surface plate,
An inner circumference side clearance measurement sensor disposed on the inner circumference side of the upper surface plate and immediately above an arbitrary position of the carrier at the start of machining;
An outer peripheral side gap measuring sensor disposed on the outer peripheral side of the upper surface plate and immediately above an arbitrary position of the carrier at the start of processing;
A double-side polishing apparatus comprising: In the double-side polishing apparatus according to claim 5,
A signal processing unit to which the inner circumferential side gap measurement sensor and the inner circumferential side gap measurement sensor are connected together;
This signal processor
In the step of lowering the upper surface plate immediately before the start of machining to the workpiece and the lower surface plate,
When the input data of the tension sensor reaches a preset landing load, the lowering of the upper surface plate is stopped, and the carrier upper surface from the inner circumference side gap measurement sensor and the outer circumference side gap measurement sensor at this time is stopped. Each of the gap data, and when at least one of the gap data exceeds a preset threshold, it is judged as abnormal, the machining process is stopped and the upper surface plate is raised,
In the workpiece machining process,
The gap data between the upper and lower surface plates from the inner circumference side gap measurement sensor and the outer circumference side gap measurement sensor, that is, the workpiece thickness data, are respectively input to obtain an average value thereof, and this value reaches a preset processing target thickness. Controlling whether to stop the machining of the workpiece and reach the upper surface plate when the target thickness is reached,
A double-side polishing apparatus characterized by In the double-side polishing apparatus according to claim 6, in the operation process when landing on the upper surface plate immediately before the start of processing,
The carrier rotation start time is set in advance so that the carrier is rotating by a predetermined amount around the center axis of the carrier when the upper surface plate descends at a slow speed to land on the work surface. And the amount of rotation of the carrier is (1 / number of workpieces) × N (where N is an integer),
A processing method of a double-side polishing apparatus characterized by the above.

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