TWI709457B - Surface polishing apparatus and carrier - Google Patents

Abstract

Even if the vehicle is a vehicle that does not transmit light In addition, the thickness of the carrier can also be measured by laser light, and the trouble of removing the carrier from the grinding device during the thickness measurement of the carrier is eliminated, and the gap between the thickness of the workpiece and the thickness of the carrier is eliminated. Management becomes easier, and the operation steps are deleted.

A tool used to grind the carrier (30) The surface grinding device (1) of the piece (40) has a thickness measuring device (X) for measuring the thickness of the workpiece (40) and the carrier (30). The aforementioned thickness measuring device (X) is configured to illuminate the laser To the workpiece (40) and the carrier (30), and measure the thickness based on the reflected light from the front and back. The carrier (30) has: a workpiece holding hole (40) for holding the workpiece (40) The main body part (31) of 32) and the thickness measuring part (Y) provided with a measuring hole (34) and a light-transmitting member (35) embedded in the measuring hole (34).

Description

Plane grinding device and carrier

The present invention relates to a plane polishing device for polishing the front and back surfaces of a workpiece such as a semiconductor wafer, and a carrier for holding the aforementioned workpiece.

A flat surface polishing device used to polish plate-shaped workpieces such as semiconductor wafers or glass substrates is generally configured to have an upper and lower platen that are rotatably arranged, and a carrier that holds the aforementioned workpiece. The held work piece is clamped by the upper and lower platens, and the front and back sides of the work are polished by the upper and lower plates.

Such a flat polishing device is known to obtain a high flatness workpiece by terminating the polishing when the difference between the thickness of the workpiece and the thickness of the carrier becomes a predetermined value. Therefore, in the past, as disclosed in Patent Document 1, the thickness of the workpiece and the thickness of the carrier were measured separately, the difference between the thickness of the workpiece and the thickness of the carrier (gap) was managed, and the grinding process was performed until the gap became a predetermined value. .

However, as disclosed in Patent Document 1, it is at the beginning of polishing The thickness of the carrier is measured before, and the thickness of the workpiece is measured when it is not grinding (the timing of switching the grinding stone), so it has the disadvantage of poor work efficiency.

On the other hand, Patent Document 2 discloses a thickness measuring device in which a laser beam is mounted on a support frame. The thickness measuring device irradiates a workpiece with the laser beam, and calculates the thickness based on the reflected light reflected from the surface and back of the workpiece. The thickness of the workpiece. According to this, the thickness of the workpiece can be measured during polishing, so the work efficiency is excellent. As for the carrier, since the reflected light from the carrier is weak, the reflected light will be regarded as a measurement anomaly, so no laser light is used for thickness measurement.

Since the carrier used in the surface grinding process is repeatedly used, it must be durable, so in general, a carrier with excellent durability is used. Among them, a carrier made of metal or fiber-reinforced plastic that does not have light transmission (transmittance) or a carrier with low light transmission (transmission) and weak reflected light (hereinafter referred to as " The reflected light of a carrier that does not have light transmittance (transparent)") has weak intensity, so the peak value of the measurement data obtained from the reflected light will be affected by the vibration of the polishing device during the polishing process. If the information is overwritten, it will be treated as noise (it becomes a measurement anomaly). Especially in the case of metal carriers, since the laser light does not penetrate, the thickness measurement cannot be performed with the laser light. Therefore, when a metal carrier is used to polish a workpiece, the carrier must be taken out of the polishing device during non-polishing and the thickness must be measured using a measuring instrument such as a micrometer, which results in poor work efficiency.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2010-45279 A

[Patent Document 2] JP 2008-227393 A

Therefore, the technical problem of the present invention is that even when the carrier is the above-mentioned non-transparent (transparent) carrier, the thickness of the carrier can be measured by laser light, and there is no need to measure When the thickness of the carrier is to be removed from the polishing device, the workpiece can be polished efficiently due to gap management.

In order to achieve the above-mentioned object, according to the present invention, there is provided a surface grinding device, which has an upper and lower platen that are rotatably arranged, and a carrier for holding a workpiece, and the workpiece held on the carrier is The fixed plate and the lower fixed plate are used to clamp and grind both sides of the workpiece. The characteristic is that the flat surface grinding device has a thickness measuring device for measuring the thickness of the workpiece and the carrier, and the thickness measuring device is configured to The light is directed to the workpiece and the carrier, and the thickness of the workpiece and the carrier is measured based on the reflected light from the surface of the workpiece and the carrier and the reflected light from the back. The carrier has: The body part of the workpiece holding hole of the workpiece, and the thickness measurement used to measure the thickness of the carrier The thickness measuring part has a measuring hole formed at a position different from the aforementioned workpiece holding hole, and a light-transmitting member inserted into the measuring hole, and the light-transmitting member has a higher light transmittance (translucent) than the aforementioned body The part is also excellent, and the thickness of the light-transmitting member is equal to the thickness of the body part, and the front and back of the light-transmitting member are on the same plane as the front and back of the body.

Regarding the surface polishing device of the present invention, it is preferable that the diameter of the measuring hole is smaller than the diameter of the workpiece holding hole. Moreover, the polishing rate of the light-transmitting member is preferably equal to or lower than the polishing rate of the main body.

Furthermore, according to the present invention, there is provided a carrier, which is arranged between the upper and lower plates of the planar grinding device, and is used to hold the workpieces ground by the upper and lower plates, characterized in that the aforementioned carrier, It is provided with a body part having a workpiece holding hole for holding the aforementioned workpiece, and a thickness measuring part for measuring the thickness of the carrier with laser light. The thickness measuring part is formed at a position different from the aforementioned workpiece holding hole The measuring hole of the measuring hole and the light-transmitting member embedded in the measuring hole, the light-transmitting member (translucent) is better than the aforementioned body, and the thickness of the light-transmitting member is the same as the thickness of the aforementioned body The thickness is equal, and the front and back of the light-transmitting member are on the same plane as the front and back of the aforementioned main body.

Regarding the carrier of the present invention, it is preferable that the diameter of the measuring hole is smaller than the diameter of the workpiece holding hole. Moreover, the polishing rate of the light-transmitting member is preferably equal to or lower than the polishing rate of the main body.

As described above, according to the present invention, even if the carrier is a material with no light transmittance (transmittance) or low light transmittance (transparency), the thickness of the carrier can be measured by laser light, and When measuring the thickness of the carrier, there is no need to specifically remove the carrier from the polishing device, so the gap management between the thickness of the workpiece and the thickness of the carrier becomes easy, and the number of work can be reduced. In addition, it can prevent the deformation or damage of the carrier caused by the removal and reloading of the carrier, so it can prevent the deformation or damage from making the contact between the upper and lower table and the polishing surface become uneven and the state of the polishing surface becomes uneven. Stability leads to deviations in the machining accuracy of the workpiece, and stable grinding can be achieved.

1: Plane grinding device

2: Upper fixing

3: next fix

30: Vehicle

31: body part

32: Workpiece holding hole

34: Measuring hole

35: light transmitting member

40: Workpiece

50: 2nd probe

X: Thickness measuring device

Y: Thickness measurement department

Fig. 1 is a schematic cross-sectional view showing the overall structure of an embodiment of a flat surface polishing apparatus related to the present invention.

Fig. 2 is a schematic plan view showing a plurality of carriers arranged on the upper plate and the lower plate.

Fig. 3 is a schematic enlarged view showing the state of measuring the thickness of the workpiece.

Fig. 4 is a schematic plan view showing the first example of the carrier of the present embodiment.

Fig. 5 is a schematic plan view showing a second example of the aforementioned carrier.

Fig. 6 is a schematic plan view showing a third example of the aforementioned carrier.

Fig. 7 is a schematic plan view showing a fourth example of the aforementioned carrier.

Fig. 8 is an enlarged view of a schematic part showing the state of measuring the thickness of the carrier.

Hereinafter, an embodiment of the surface polishing apparatus of the present invention will be described in detail using drawings. Regarding the surface polishing device 1 of this embodiment, it is used to polish the front and back surfaces of a plate-shaped workpiece 40 having light permeability (translucent) like a silicon wafer or a glass substrate, as shown in FIG. The body of the surface grinding device 1 has an upper fixed plate 2 and a lower fixed plate 3, a sun gear 4 and an internal gear 5 rotatably arranged around an axis L, and the lower fixed plate 3 is mounted at equal intervals and engaged The metal carrier 30 on the aforementioned sun gear 4 and internal gear 5. In the carrier 30, a workpiece holding hole 32 for holding the aforementioned workpiece 40 is formed.

In addition, the surface polishing device 1 includes first to fourth drive shafts 2a to 5a, which are arranged coaxially with the axis L as the center, and the lower end is connected to a drive source such as a drive motor, and is connected to the first drive shaft 2a A driver 10 is mounted on the upper end of the second drive shaft 3a, the upper end of the second drive shaft 3a is connected to the aforementioned bottom plate 3, the upper end of the third drive shaft 4a is connected to the aforementioned sun gear 4, and the upper end of the fourth drive shaft 5a is connected to the aforementioned internal gear 5. In connection, the upper surface plate 2 and the lower surface plate 3, the sun gear 4, and the internal gear 5 are driven and rotated by the drive shafts 2a to 5a with the axis L as the center. In addition, the driving of the upper surface plate 2 by the aforementioned first driving shaft 2a is made clear from the following description.

Above the upper fixed plate 2, a support frame 6 integrated with the machine body is provided. On the support frame 6, a lifting actuator 7 such as a motor or an air cylinder is mounted, and the lifting actuator 7 Lifting rod 7a A fixed plate suspension 8 is connected to the lower end of the plate, and the upper fixed plate 2 is supported by a plurality of support studs 8a in the fixed plate suspension 8. Between the inner circumference of the fixed plate suspension 8 and the outer circumference of the lifting rod 7a, a bearing 12 is provided. With the bearing 12, the lifting rod 7a and the fixed plate suspension 8 are connected in the vertical direction. They are fixed to each other, but are relatively free to rotate in the direction of rotation with the aforementioned axis L as the center.

Then, during the grinding of the workpiece 40, when the lifting rod 7a is extended by the lifting actuator 7 and the upper platen 2 is lowered to the grinding position in FIG. 1, the hook 9 and the hook 9 provided on the upper platen 2 The driver 10 at the upper end of the first drive shaft 2a is engaged, so that the upper platen 2 passes through the driver 10 and is driven and rotated by the first drive shaft 2a.

During the non-grinding of the workpiece, the lifting rod 7a is contracted by the lifting actuator 7 and the upper surface plate 2 is raised from the grinding position to the retracted position, and then the hook 9 and the actuator 10 are released from engagement .

As shown in FIG. 1, a polishing pad 11 having a uniform thickness is stuck on the lower surface of the upper surface plate 2 and the upper surface of the lower surface plate 3. As the polishing pad 11, a nonwoven fabric product or a polyurethane product is used. However, the polishing pad 11 is not essential, and it may be a structure in which the polishing pad 11 is adhered to a stone or a structure in which the surface of the table itself becomes a polishing surface.

The aforementioned carrier 30 is a carrier made of a material that does not have light transmittance (translucency) or has low light transmittance (translucency). As the material of such a carrier, there are: stainless steel, SK steel, titanium and other metals; ceramics; fiber-reinforced plastics using glass fiber, carbon fiber, aramid fiber, etc.; aramid resin; vinyl chloride; cloth phenolic plastic; or Is to wait Those coated with materials having abrasion resistance, chemical resistance, and durability, etc., but metal is described here. As shown in FIG. 4, the carrier 30 has a gear 31a on the outer periphery of the body portion 31, and has a workpiece holding hole 32 having the same shape as the workpiece at an eccentric position. The workpiece holding hole 32 holds the aforementioned Work 40 (refer to FIGS. 1 and 2). The carrier 30 is placed on the polishing pad 11 of the lower platen 3, and the outer gear 31a is engaged with the sun gear 4 and the internal gear 5, thereby rotating the sun gear 4 and the internal gear 5, Come and revolve around the aforementioned sun gear 4 while rotating.

The aforementioned carrier 30 is made thinner than the thickness of the workpiece 40 before polishing, and when the workpiece 40 before polishing is held in the workpiece holding hole 32, the workpiece 40 protrudes upward from the surface of the carrier 30 (refer to Figure 1 and Figure 3).

Furthermore, the aforementioned carrier 30, as shown in FIGS. 4 to 7, has a slurry introduction hole 33. When the workpiece 40 is polished, the polishing slurry supplied from a slurry supply part not shown passes through the slurry introduction hole. 33 and all over the front and back of the workpiece 40.

When the workpiece 40 is polished by the plane polishing device 1, the upper platen 2 is raised to the retracted position, as shown in FIG. 2, a plurality of the carriers 30 are arranged on the lower platen at equal intervals 3, and the aforementioned gear 31a formed on its outer periphery is engaged with the aforementioned sun gear 4 and internal gear 5. Then, after the workpiece 40 is held in the workpiece holding hole 32 of each carrier 30, the upper platen 2 is lowered to the grinding position as shown in FIG. 1, and the carrier is clamped by the upper platen 2 and the lower platen 3 30. In this state, the upper fixed plate 2 and the lower fixed plate 3, the sun gear 4 and the internal gear 5 are rotated at the preset rotation direction and rotation speed through the aforementioned drive shafts 2a~5a. The grinding slurry is supplied between the lower platen 3 and the front and back surfaces of the workpiece 40 held by the carrier 30 that rotates and revolves around the sun gear 4 are ground by the upper platen 2 and the lower platen 3.

In the example of FIG. 2, four carriers 30 are arranged side by side at equal intervals in the circumferential direction, but the number of carriers 30 arranged on the bottom platen 3 is arbitrary.

In addition, the surface polishing apparatus 1 of this embodiment is configured to measure the thickness (T) of the workpiece 40 and the thickness (t) of the carrier 30, respectively, and the difference between the thickness of the workpiece 40 and the thickness of the carrier 30 ( The polishing is completed when the gap) becomes the desired value, and polishing in the gap management method is performed. Therefore, the aforementioned plane polishing device 1 has an optical thickness measuring device X for measuring the thickness of the workpiece 40 and the thickness of the carrier 30 with laser light.

The thickness measuring device X is configured to be capable of instantly measuring both the thickness of the workpiece 40 and the thickness of the carrier 30 during the grinding of the workpiece 40. Therefore, the thickness measuring device X, as shown in FIG. 1, has: a light source unit 20 that outputs laser light in the infrared wavelength range; and irradiates the laser light output by the light source unit 20 toward the workpiece 40 to measure the workpiece 40 The thickness of the first probe 21; and the second probe 50 that irradiates the laser light output from the light source unit 20 toward the carrier 30 to measure the thickness of the carrier 30.

The first probe 21 is arranged to rotate together with the upper platen 2. That is, the first probe 21 is attached to the fixed plate suspension 8 or the supporting stud 8a, etc., and is mounted downward through the holding bracket 24, thereby being arranged above the upper plate 2, and The first optical cable 22 is connected to the aforementioned light source unit 20 through a rotary joint 23. Then, as shown in FIG. 3, in the grinding process of the workpiece 40, the workpiece 40 is irradiated with laser light through the first measurement window 25 formed on the upper surface plate 2 for measurement, and the workpiece 40 is received Reflected light reflected on the surface and back. Based on the received measurement data of reflected light, it is sent to the calculation control unit 29 through the first optical cable 22, and the calculation control unit 29 performs calculation processing to calculate the thickness of the workpiece 40.

The thickness of the workpiece 40 by the first probe 21 is measured when the workpiece 40 held by the carrier 30 that rotates and revolves around the sun gear 4 passes directly under the first probe 21, that is, the first measurement window. When it is directly below 25.

In addition, based on the measurement data of the reflected light received by the first probe 21, it can be directly sent to the arithmetic control unit 29 through the first optical cable 22 in the state of light, but it can also be converted to electrical by the first probe 21. The signal is sent to the arithmetic control unit 29 via an electric cable (not shown) connecting the first probe 21 and the arithmetic control unit 29 via a rotary joint 23, or may be transmitted wirelessly.

The first measurement window 25 is arranged directly below the first probe 21, and has a through hole 26 penetrating the upper platen 2 up and down, a sleeve 27 fitted into the through hole 26, and a The casing 27 The bottom through the plate 28. In addition, the polishing pad 11 adhered to the upper platen 2 has an opening 11a in the portion where the first measurement window 25 is provided.

The sleeve 27 is a cylindrical body made of synthetic resin or glass, and has an outer diameter approximately equal to the diameter of the passage hole 26, and the flange portion 27a at the upper end is fixed to the upper surface of the upper plate 2. In addition, the through hole 26 and the sleeve 27 are not limited to a cylindrical body, and may have a shape such as a polygonal cylindrical body.

In addition, the transparent plate 28 is made of synthetic resin or glass and other light-transmitting (translucent) material, preferably a transparent material formed into a plate shape, and installed so as to plug the lower end of the sleeve 27 Open up.

On the other hand, the second probe 50 used to measure the thickness of the carrier 30 is mounted on the support frame 6 facing downward, and is connected to the light source unit 20 via a second optical cable 51. The second probe 50 is different from the first probe 21 that rotates with the upper platen 2 in that it is fixedly arranged at a fixed position of the support frame 6 by an appropriate fixing means.

Since the thickness of the carrier 30 is measured by the second probe 50 through the upper surface plate 2 that rotates, the upper surface plate 2 is provided with one or more second measurement devices for the laser light to penetrate窗部52. In the embodiment shown in FIG. 2, a total of five second measurement window portions 52 are arranged on the same circumference as the aforementioned first measurement window portion 25 and are arranged at equal intervals. However, the arrangement position of the second measurement window 52 may be a position different from the first measurement window 25 in the radial direction of the upper platen 2.

And, as shown in FIG. 8, the aforementioned second measurement window 52, Like the first measurement window 25 described above, it has a through hole 26 that penetrates the upper platen 2 up and down, a sleeve 27 fitted in the through hole 26, and a permeable plate 28 attached to the lower end of the sleeve 27 . In addition, the polishing pad 11 adhered to the upper platen 2 is provided with an opening 11a in the portion where the second measurement window portion 52 is provided similarly to the portion where the first measurement window portion 25 is provided.

The sleeve 27 is a cylindrical body made of synthetic resin or glass, and has an outer diameter approximately equal to the diameter of the passage hole 26, and the flange portion 27a at the upper end is fixed to the upper surface of the upper plate 2. In addition, the through hole 26 and the sleeve 27 are not limited to a cylindrical body, and may have a shape such as a polygonal cylindrical body.

In addition, the transparent plate 28 is made of synthetic resin or glass and other light-transmitting (translucent) material, preferably a transparent material formed into a plate shape, and installed so as to plug the lower end of the sleeve 27 Open up.

However, when the carrier 30 is made of metal, even if the second probe 50 is used to irradiate the carrier 30 with laser light, the laser light cannot penetrate the carrier 30, and the back surface of the carrier 30 cannot be obtained. It is impossible to measure the thickness of the carrier 30 because of the reflected light from the side.

Therefore, in the present invention, as shown in FIGS. 1 to 4, one thickness measuring part Y for measuring the thickness by laser light is formed on the carrier 30. The thickness measuring part Y is formed by a measuring hole 34 formed at a different position from the aforementioned workpiece holding hole 32 and slurry introduction hole 33 and a light-transmitting member 35 embedded in the measuring hole 34.

The aforementioned measuring hole 34 penetrates the carrier 30 from the surface to the back The diameter of the circular hole is preferably smaller than the diameter of the aforementioned workpiece holding hole 32. Thereby, the strength of the carrier 30 is not impaired, and the wear caused by the contact between the light-transmitting member 35 provided in the measuring hole and the polishing surface can be suppressed. The measuring hole 34 is preferably formed as close to the center of the carrier 30 as possible. In addition, the shape of the aforementioned measuring hole 34 is not limited to a circular shape, and may be a polygonal shape.

The light-transmitting member 35 is formed of a material having light-transmitting properties (light-transmitting), which is superior to the light-transmitting properties (light-transmitting) of the main body portion 31, and has a thickness equal to that of the main body portion 31. The thickness is such that the front and back surfaces of the main body portion 31 and the front and back surfaces are the same plane, and are inserted into the measuring hole 34.

Since the metal carrier 30 is formed with the thickness measuring part Y formed by the measuring hole 34 and the light-transmitting member 35 as described above, the second probe 50 is used to irradiate the light-transmitting member 35 with laser light. The reflected light from the surface and back of the light-transmitting member 35 can be obtained, and as a result, the thickness of the carrier 30 can be measured.

The aforementioned light-transmitting member 35, as a material having light-transmitting properties (light-transmitting properties), can be, for example, acrylic resin, polyurethane resin·polyethylene terephthalate resin (PET) and other synthetic resins; quartz; sapphire ; Glass; silicon, etc., it is important to appropriately select a material that has better light transmittance (transmittance) than the material of the main body 31. In particular, it is important to appropriately select a material (infrared transmissive material) that is superior to the material of the main body 31 in the light transmittance (transmittance) of laser light in the infrared wavelength range. In addition, the light-transmitting member 35 faces the aforementioned measuring hole The installation of 34, for example, can also be connected by an adhesive, or a wedge fitting, and can be installed by appropriate means.

In addition, the polishing rate of the light-transmitting member 35 is preferably equal to or lower than the polishing rate of the main body 31 (more difficult to polish). The reason is that during the grinding process, the grinding surface of the lower platen 3 is always in contact with the lower surface of the body portion 31, so the body portion 31 is ground, and as the grinding process proceeds, the upper platen 2 and the body portion The distance between the upper surface of the upper surface 31 is shortened, and the grinding surface of the upper surface plate 2 is brought into contact with the upper surface of the main body portion 31, thereby causing the main body portion 31 to be ground. Therefore, if the polishing rate of the transparent member 35 is higher than the polishing rate of the main body 31 (easier to be polished), the transparent member 35 will be polished and become thinner than the main body 31, resulting in a thick The measurement accuracy is reduced.

As shown in FIG. 8, in the grinding process of the workpiece 40, the thickness measurement of the carrier 30 performed by the second probe 50 is the second measurement window 52 formed on the rotary table 2 and This is performed when the light-transmitting member 35 mounted on the carrier 30 is positioned directly below the second probe 50. At this time, the laser light irradiated by the second probe 50 to the light-transmitting member 35 is reflected on the surface and back of the light-transmitting member 35, and the reflected light is received by the second probe 50 as measurement data . The received measurement data is sent to the calculation control unit 29 via the aforementioned second optical cable 51, and the calculation control unit 29 performs calculation processing to calculate the thickness of the carrier 30.

The laser light from the aforementioned second probe 50 can be used on the workpiece 40 Irradiation is often performed during the polishing process, but it can be controlled to only irradiate at the moment when the second measuring window 52 of the upper platen 2 and the light-transmitting member 35 of the carrier 30 are aligned directly below the second probe 50. In this case, by arranging a plurality of second measurement windows 52 at equal intervals, irradiation can be performed with regular timing. In addition, by providing the second measurement window 52 in plural, the number of measurements is increased and the measurement accuracy is improved.

In addition, the measurement data of the second probe 50 can be directly sent to the arithmetic control unit 29 in the state of light through the second optical cable 51, but it can also be converted into an electrical signal by the second probe 50. An electric cable (not shown) connected to the second probe 50 and the aforementioned arithmetic control unit 29 is sent to the arithmetic control unit 29, or wireless transmission may be used.

If the thickness of the workpiece 40 and the thickness of the carrier 30 are measured in this way during the grinding process of the workpiece 40, the two measurement data are compared in the aforementioned calculation control unit 29, and the thickness of the workpiece 40 is compared with the thickness of the carrier 30. Polishing ends when the difference in thickness reaches a desired value.

In addition, when measuring the thickness of the workpiece 40 and the thickness of the carrier 30 during the grinding process of the workpiece 40 as described above, although the first probe 21 and the second probe 50 are received from the front and back of the workpiece 40 The reflected light of both the reflected light and the reflected light from the front and back of the light-transmitting member 35 of the carrier 30, but the peak values of the two are different, and it is necessary to use the difference to adjust to: make the first probe 21 Only the reflected light from the workpiece 40 is accepted as the measurement data, and the second probe 50 only accepts the reflected light from the light-transmitting member 35 of the carrier 30 as the measurement data.

The thickness measurement of the aforementioned carrier 30 can be performed when the workpiece 40 is not being ground. For example, when the new workpiece 40 is set on the carrier 30 before the grinding starts, or when the washing step is performed with pure water after the grinding of the workpiece 40, the time between batch processing can be used. The thickness measurement at this time is to stop the upper plate 2 so that any of the second measurement windows 52 of the upper plate 2 are positioned directly below the second probe 50, and slowly connect the sun gear 4 to the inner The gear 5 rotates to cause the carrier 30 to rotate and revolve, and the light-transmitting member 35 passes under the second measurement window 52. As described above, in the device for measuring the thickness of the carrier 30 when the workpiece 40 is not being polished, there may be one second measurement window 52 formed on the upper platen 2.

5 to 7 show a modification of the carrier 30 of the present invention.

The difference between the carrier 30 shown in FIG. 5 and the carrier 30 shown in FIG. 4 is that three thickness measuring parts Y are formed at equal intervals (120-degree intervals) in the circumferential direction of the carrier 30. As described above, by providing a plurality of thickness measurement parts Y, the number of acquisitions of measurement data can be increased.

In the carrier 30 shown in FIG. 6, three workpiece holding holes 32 are formed at equal intervals (120 degree intervals) in the circumferential direction of the carrier 30, and three adjacent workpiece holding holes 32 are individually formed The slurry introduction hole 33 has a single thickness measuring part Y formed in the center of the carrier 30. The center part of the carrier 30 is at the position where the movement of the carrier 30 is the least when it rotates and revolves. Therefore, by providing the thickness measuring part Y here, it is not easy to place the light-transmitting member 35 in the grinding process. Grinding plate 2 and bottom plate 3 advantage.

The difference between the carrier 30 shown in FIG. 7 and the carrier 30 shown in FIG. 6 is that a plurality of thickness measuring parts Y are formed. That is, each of the slurry introduction holes 33 is sandwiched to form two thickness measuring parts Y, whereby a total of three groups, that is, six thickness measuring parts Y are formed.

In this way, in the surface polishing apparatus 1 of the present embodiment, even if the carrier 30 made of a material having a reflected light intensity lower than the reflected light intensity from the workpiece 40 is used when the laser light is irradiated, the workpiece 40 can be measured. The thickness of φ and the thickness of the carrier 30 are polished in a gap management manner. As a result, a workpiece 40 with high flatness can be obtained. Moreover, the measurement of the thickness of the aforementioned carrier 30 can be carried out by laser light without taking out the carrier 30 by setting the carrier 30 in the flat polishing device. Therefore, unlike the conventional device, the carrier must be removed from the device and The measurement is performed by a micrometer, etc., so it saves the trouble of measurement and has excellent workability. Moreover, since it is not necessary to remove and reload the carrier every time, it can prevent the deformation or damage of the carrier, so it can prevent the contact between the upper and lower plates on the grinding surface from becoming uneven and grinding due to the deformation or damage. When the state of the surface becomes unstable, deviations in the machining accuracy of the workpiece occur, and as a result, stable polishing processing can be realized.

As mentioned above, the surface polishing device of the present invention has been described, but the present invention is not limited to the above-mentioned embodiments and modifications, and various design changes can be made without departing from the scope of the patent application. For example, as described above, the first probe 21 and the second probe 50 can receive both the reflected light from the front and back surfaces of the workpiece 40 and the reflected light from the front and back surfaces of the light-transmitting member 35 of the carrier 30. The anti Since light is emitted, either of the probes can be omitted, and the first probe 21 or the second probe 50 is configured to measure both the thickness of the workpiece 40 and the thickness of the carrier 30. Moreover, it may be configured to omit any one of the first measurement window 25 and the second measurement window 52, and use the first measurement window 25 or the second measurement window 52 to measure the thickness of the workpiece 40 And the thickness of the carrier 30.

1: Plane grinding device

2: Upper fixing

2a: 1st drive shaft

3: next fix

3a: 2nd drive shaft

4: Sun gear

4a: 3rd drive shaft

5: Internal gear

5a: 4th drive shaft

6: Support frame

7: Actuator for lifting

7a: Lifting rod

8: Fixing plate suspension

8a: Support stud

9: hook

10: Drive

11: Grinding pad

11a: opening

12: Bearing

20: Light source

21: The first probe

22: The first optical cable

23: Rotary joint

24: Keep the bracket

25: The first measurement window

29: Calculation Control Department

30: Vehicle

31: body part

32: Workpiece holding hole

34: Measuring hole

35: light transmitting member

40: Workpiece

50: 2nd probe

51: 2nd optical cable

52: The second measurement window

X: Thickness measuring device

Y: Thickness measurement department

Claims (6)

A surface grinding device is provided with an upper and lower plate that are configured to rotate freely, and a carrier for holding a workpiece, and the workpiece held on the carrier is clamped and held by the upper and lower plates. Grinding both sides of the workpiece is characterized in that the plane polishing device has a thickness measuring device for measuring the thickness of the workpiece and the carrier, and the thickness measuring device is configured to direct laser light to the workpiece and the carrier, The thickness of the workpiece and the carrier is measured according to the reflected light from the surface of the workpiece and the carrier and the reflected light from the back. The carrier has: a body portion with a workpiece holding hole for holding the workpiece, And a thickness measuring part used to measure the thickness of the carrier, the thickness measuring part having a measuring hole formed at a position different from the aforementioned workpiece holding hole, and a light-transmitting member embedded in the measuring hole, the light-transmitting member The light transmittance is better than that of the main body, and the thickness of the light-transmitting member is equal to the thickness of the main body, and the front and back of the light-transmitting member are on the same plane as the front and back of the main body. The surface polishing device according to claim 1, wherein the diameter of the measuring hole is smaller than the diameter of the workpiece holding hole. The surface polishing device according to claim 1 or 2, wherein the polishing rate of the light-transmitting member is equal to or lower than the polishing rate of the main body. A carrier, which is arranged on the upper and lower plates of a plane grinding device Between the fixed plates, it is used to hold the workpiece ground by the upper and lower fixed plates. The carrier is characterized in that the carrier has: a body portion with a workpiece holding hole for holding the workpiece, and a mine A thickness measuring part for measuring the thickness of the carrier by light irradiation. The thickness measuring part has a measuring hole formed at a position different from the aforementioned workpiece holding hole, and a light-transmitting member embedded in the measuring hole. The light of the light-transmitting member transmits The performance is better than that of the main body, and the thickness of the light-transmitting member is equal to the thickness of the main body, and the front and back of the light-transmitting member are on the same plane as the front and back of the main body. The carrier according to claim 4, wherein the diameter of the measuring hole is smaller than the diameter of the workpiece holding hole. The carrier according to claim 4 or 5, wherein the polishing rate of the transparent member is equal to or lower than the polishing rate of the main body.

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