JP2012223852A - Double-side polishing device, and polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-side polishing device which does not require recovery work and cleaning work to improve continuity of processes only by adding an inexpensive and simple structure in order to give peeling force to a work by supplying a minute amount of fluid and securely prevent sticking of the work on an upper surface plate.SOLUTION: The double-side polishing device laps or polishes both front and rear surfaces of the work by the upper surface plate and lower surface plate. The double-side polishing device includes: a pressure fluid discharge device 21 which sequentially supplies the minute amount of pressure fluid proceeding in a flow channel space 222 through a clearance formed by pressing a seal ball 220 by a turning rod 218, and discharges the pressure fluid to an external through a plurality of flow channel spaces 222; and a plurality of fluid discharge holes arranged on the upper surface plate so as to communicate with the plurality of flow channel spaces 222 of the pressure fluid discharge device 21, and carries out discharge of flowing the pressure fluid between the upper surface plate and the work on all of the works.

Description

  The present invention relates to a double-side polishing apparatus that polishes both surfaces of a workpiece with an upper surface plate and a lower surface plate, and more particularly to a double-side polishing device that prevents the workpiece from sticking to an upper surface plate. The present invention also relates to a polishing method for preventing a workpiece from sticking to an upper surface plate in a double-side polishing apparatus.

  With a double-side polishing machine, the upper platen is lifted after polishing, and then the work on the lower platen is collected, but sometimes the upper platen rises with the workpiece attached to the upper platen. There is. When such a sticking phenomenon occurs, it is necessary to rotate the upper platen to a position where the stuck workpiece can be collected, and to manually remove the workpiece from the upper platen at that position. A large time loss occurs. In addition, if the workpiece peels off from the upper surface plate before it is collected and falls or breaks, and fragments of the workpiece are scattered on the lower surface plate, in addition to the loss due to the deterioration of the workpiece, the debris is further settled manually. A lot of labor and time are required for the cleaning work to completely remove from the board.

  In particular, in the case of an automatic machine that automatically supplies and discharges workpieces, if even one piece of workpiece is stuck as described above, the processing is interrupted, and whenever the sticking phenomenon occurs, the above manual return work and Since the cleaning work is performed, the productivity is significantly reduced. Therefore, in the case of a double-side polishing apparatus, particularly an automatic machine that performs an automatic process, prevention of sticking of the work to the upper surface plate has been an important issue.

Therefore, such a double-side polishing apparatus has a function of preventing sticking, and avoids the return operation and the cleaning operation as described above to prevent a decrease in productivity. As a conventional technique of a polishing apparatus having such a sticking prevention function, for example, the invention described in Patent Document 1 (Japanese Patent No. 4163485, title of invention “Double-side polishing apparatus and polishing method using the same”) It has been known.
In the double-side polishing apparatus described in Patent Document 1, when the upper platen is raised, pressurized slurry is appropriately supplied from all the slurry supply ports. In particular, the slurry supply port is formed over the entire upper platen to form a workpiece. Is effective regardless of where it is located. Further, since the slurry supply port is used, it is not necessary to open a separate supply port in the upper surface plate. Moreover, high quality processing is performed by individually controlling the slurry supply amount.

Further, as a prior art of another polishing apparatus having a sticking prevention function, for example, an invention described in Patent Document 2 (Japanese Patent No. 3891175, title of invention “work polishing apparatus and polishing method”) is known. ing.
In the polishing apparatus described in Patent Document 2, the same number of discharge holes as the work holding holes are provided on the outer peripheral side of the work, and the mist fluid is discharged onto the work. The reason for discharging the mist-like fluid is that the workpiece may float or move with only “water” and may be damaged. Also, with “air” alone, a large discharge pressure is required and the workpiece is distorted. This is because there is a concern that it may occur and the work surface may dry out.

  Further, as a conventional technique of another polishing apparatus having a sticking prevention function, for example, the invention described in Patent Document 3 (Japanese Utility Model Laid-Open No. 59-109446, the name of the invention “double-sided processing apparatus”) is known. Yes. In the double-sided processing apparatus described in Patent Document 3, a large number of extrusion rods are provided, and a workpiece is extruded by the rods and peeled off from the upper surface plate.

  Further, as a prior art of another polishing apparatus having a sticking prevention function, for example, the invention described in Patent Document 4 (Japanese Patent Laid-Open No. 55-48574, the title “Polishing Method”) is known. . In the polishing method described in Patent Document 4, the upper surface plate is slightly raised, and after the liquid is filled to form a liquid layer, the work is naturally dropped.

Japanese Patent No. 4163485 Japanese Patent No. 3891675 Japanese Utility Model Publication No. 59-109446 Japanese Patent Laid-Open No. 55-48574

In the double-side polishing apparatus described in the cited document 1, the structure is simplified by using both the slurry supply and the sticking prevention, but an expensive slurry is consumed outside the processing step. This was an increase in running costs.
Further, the slurry supply ports on the outer peripheral side of the surface plate are generally sparsely arranged, and there are cases where there is almost no sticking prevention effect depending on the work stop position.
In addition, a structure in which a flow rate adjusting valve is provided for each of a number of slurry supply ports is adopted. However, such a structure requires an installation space on the surface plate at the same time as the equipment cost increases, and each control is further controlled. Since the valves are connected to the control device and controlled individually, the entire control system has become very complicated.

  In addition, after polishing, it is necessary to immediately spray water to wash away the slurry adhering to the work surface from the work surface to expose the surface, to prevent the abrasive from sticking due to drying, and to check for defects etc. Discharge of expensive slurry to the workpiece when the upper platen is raised after the end of machining as in the prior art is usually undesirable because excessive slurry will remain, and this will adversely affect the next process. There must be.

  Further, in the polishing apparatus described in the cited document 2, a large amount of mist-like fluid containing water is discharged onto the surface plate to prevent the workpiece from sticking when the upper surface plate is raised. Or a large amount of water stays on the lower surface plate due to the water of the mist-like fluid, which hinders subsequent operations.

  In addition, fluid is supplied to each supply channel at the same time, and the discharge pressure usually decreases. At the same time, the fluid flows to the one where the end of the supply channel is open (the one with no workpiece). The fluid supply to the direction where the end of the path is blocked (the direction where the workpiece is stuck) is reduced, and the peeling force may be weak or not act. Therefore, there is a problem that adjustment to give an appropriate peeling force is difficult.

  Further, since the double-sided processing apparatus described in the cited document 3 is configured to extrude mechanically, the force can be controlled, but the configuration is complicated and expensive.

  Further, in the polishing apparatus described in the cited document 4, the workpiece is dropped by its own weight. However, it takes time until the workpiece is dropped, and in addition, the process cannot be shortened because the time until dropping is not fixed. In addition, it is not easy to detect whether the workpiece has fallen by simply raising the upper surface plate. For example, it is necessary to raise the upper surface plate significantly, and there is a risk of the workpiece falling at this time. The problem included.

  The above-mentioned problems have existed in the past, and various countermeasures have been proposed and implemented so far, but can be carried out easily and at low cost without major modifications to conventional equipment, and moreover, conventional processing There was a demand for measures that would not adversely affect the process.

  Therefore, the present invention has been made in view of the above-described problems, and the object thereof is to add a peeling force to a workpiece by supplying a small amount of fluid only by adding an inexpensive and simple configuration. An object of the present invention is to provide a double-side polishing apparatus and a polishing method that reliably prevent a workpiece from sticking to a surface plate and improve the continuity of the process without using a return operation and a cleaning operation.

The invention according to claim 1 of the present invention is
In a double-side polishing machine that wraps or polishes both the front and back surfaces of the workpiece with the upper and lower surface plates,
An appropriate number of fluid ejection holes provided on the lower surface of the upper surface plate, each of which is provided at a position corresponding to the stop position of each workpiece after the polishing process,
A pressure fluid discharge device for intermittently discharging a pressure fluid from the fluid discharge hole onto the upper surface of the work in small amounts;
The double-side polishing apparatus is characterized in that a pressure fluid is allowed to flow between the lower surface of the upper surface plate and the workpiece.

The invention according to claim 2 of the present invention is
The pressure fluid discharge device comprises:
A fluid reservoir filled with pressure fluid, a plurality of holes formed on a circle at openings of a plurality of flow passage spaces communicating with the fluid reservoir, and a sealing ball pressed against the hole A plurality of ball plunger type valves provided in the respective flow path spaces, and provided in the fluid reservoir, and the fluid reservoir by pushing the sealing ball for a predetermined period by rotational movement. A swivel rod that communicates with the flow path space, and a rotation drive unit that rotationally drives the swivel rod,
The revolving rod pushes the sealing ball and sequentially supplies a small amount of pressurized fluid to the flow passage space through the gap, and the pressure fluid is supplied to each fluid discharge hole on the upper surface plate through the plurality of flow passage spaces. 2. The double-side polishing apparatus according to claim 1, wherein the double-side polishing apparatus is adapted to discharge.

The invention according to claim 3 of the present invention is
After the workpiece polishing process is completed, the workpiece is moved to a predetermined position where each workpiece is taken out, and the upper surface plate is moved to a position corresponding to the stop position of the workpiece to position each fluid discharge hole on each workpiece. A first step;
A second step of operating the pressure fluid discharge device and simultaneously raising the upper surface plate at a low speed;
After raising the upper platen by a predetermined amount, stop the operation of the pressure fluid discharge device, raise the upper platen from medium speed to high speed and reach the predetermined position, then work on the lower platen sequentially A third step to be taken out;
It was set as the grinding | polishing method of the workpiece | work characterized by consisting of.

  According to the present invention, it is possible to reliably prevent the workpiece from sticking to the upper surface plate by simply adding an inexpensive and simple configuration and applying a peeling force to the workpiece by supplying a small amount of fluid. It is possible to provide a double-side polishing apparatus and a polishing method that improve process continuity without using work and cleaning work.

It is a section lineblock diagram of a double-side polish device of a form for carrying out the present invention. It is the top view which removed the upper surface plate of the double-side polish apparatus of the form for implementing this invention. FIG. 3A is an explanatory diagram of a principle for preventing a workpiece from sticking to an upper surface plate, FIG. 3A is an explanatory diagram of a force generated when the workpiece is adhered, and FIG. It is explanatory drawing explaining a pressure fluid discharge apparatus, Fig.4 (a) is a top view, FIG.4 (b) is a front view. It is explanatory drawing explaining a pressure fluid discharge apparatus, Fig.5 (a) is an AA arrow directional view, FIG.5 (b) is a BB arrow directional view. FIG. 6A is a state diagram immediately before the ball contact, FIG. 6B is a state diagram at the time of ball contact, and FIG. It is a state figure immediately after a ball contact. It is explanatory drawing explaining another pressure fluid discharge apparatus, Fig.7 (a) is explanatory drawing of a normal width rotating rod, FIG.7 (b) is explanatory drawing of a wide-width rotating rod. It is explanatory drawing of the other pressure fluid discharge apparatus which has arrange | positioned the ball plunger type | mold valve | bulb on the multicircle. It is the top view which removed the upper surface plate of the double-side polish apparatus of the other form which has arrange | positioned two fluid discharge holes in one workpiece | work. It is the top view which removed the upper surface plate of the double-side polish apparatus of the other form which has arrange | positioned three fluid discharge holes in one workpiece | work.

  Next, a double-side polishing apparatus 100 according to an embodiment for carrying out the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6. The double-side polishing apparatus 100 is an apparatus that planarizes the workpiece 200. As shown in FIG. 1, the double-side polishing apparatus 100 includes a lower surface plate 1, an upper surface plate 2, a lower surface plate receiver 3, a base portion 4, a support portion 5, a sun gear 6, a sun gear drive shaft 7, an upper surface plate drive drum 8, Connecting portion 9, drum drive shaft 10, internal gear 11, internal gear support portion 12, work carrier 13, upper surface plate lifting device 14, upper surface plate support shaft 15, universal joint 16, upper surface plate suspension plate 17, upper surface plate A panel connecting rod 18, a pressure fluid supply device 19, a supply tube 20, a pressure fluid discharge device 21, a connection tube 22, and a fluid discharge hole 23 are provided.

Next, each configuration will be described.
As shown in FIGS. 1 and 2, the lower surface plate 1 is an annular disk and has a lapping surface / polish surface for polishing the workpiece 200 on the upper surface. Although not shown, a polishing cloth (not shown) may be attached to the upper surface of the lower surface plate 1 and the workpiece may be polished with the polishing cloth.
As shown in FIG. 1, the upper surface plate 2 is an annular disk and has a lap surface / polish surface for polishing the workpiece 200 on the lower surface. Although not shown, a polishing cloth (not shown) may be attached to the lower surface of the upper surface plate 2 and the workpiece may be polished with the polishing cloth.
Here, the lower surface plate 1 and the upper surface plate 2 are supported so as to rotate around the common rotation axis.

The lower surface plate receiver 3 is a rotating body, and the lower surface plate 1 is fixed to the upper surface of the lower surface plate receiver 3. The lower surface plate receiver 3 is rotationally driven together with the lower surface plate 1 by a lower surface plate rotation driving unit (not shown). The lower surface plate receiver 3 is disposed in the center hole of the base portion 4 and rotates independently from the base portion 4.
The base part 4 is a robust structure fixed to a pedestal (not shown), has a rotating body shape, and can support heavy objects.

The support portion 5 is, for example, an annular bearing fixed on the base portion 4 and supports and supports the lower surface plate receiver 3 from below so that the lower surface plate receiver 3 rotates smoothly.
The sun gear 6 has teeth formed on the outer peripheral side, and is disposed on the inner peripheral side (center side) of the lower surface plate 1.

The sun gear drive shaft 7 is integrally provided with the sun gear 6. A rotational force is applied to the sun gear drive shaft 7 by a sun gear rotation drive unit (not shown), and the sun gear 6 is rotated together with the sun gear drive shaft 7. The sun gear drive shaft 7 is disposed in the center hole of the lower surface plate receiver 3 and rotates independently from the lower surface plate receiver 3.
The upper surface plate driving drum 8 is a cylindrical body as shown in FIG. 1, and a plurality of fitting grooves are provided on the side surface. The upper surface plate driving drum 8 is formed so as to pass through the central holes of the lower surface plate 1 and the upper surface plate 2, and the upper surface plate driving drum 8 is provided so as to protrude from the opening of the central hole of the upper surface plate 2. ing. When the upper surface plate 2 is lowered by an elevating mechanism which will be described later, the upper surface plate driving drum 8 penetrates through the central hole of the upper surface plate 2.

The connecting portion 9 is, for example, a rotary drive claw, and the rotary drive claw enters into the fitting groove of the upper surface plate driving drum 8 and is fixedly connected to the upper surface plate 2 and the upper surface plate driving drum 8. Are concatenated.
The upper platen driving drum 8 is fixed to the upper side of the drum driving shaft 10. The drum drive shaft 10 is disposed in the central hole of the sun gear drive shaft 7 and rotates independently of the sun gear drive shaft 7. The drum drive shaft 10 is given a rotational force by an upper surface plate rotation drive unit (not shown).

The internal gear 11 has teeth formed on the inner peripheral side (center side) and is disposed on the outer peripheral side of the lower surface plate 1.
The internal gear support portion 12 includes a multistage cylindrical member, and the internal gear 11 is formed on the upper side. The internal gear support 12 is given a rotational force by an internal gear rotation drive unit (not shown), and the internal gear 11 is rotationally driven together with the internal gear support unit 12. A base portion 4 is disposed in the central hole of the internal gear support portion 12, and the internal gear support portion 12 rotates independently from the base portion 4.

  Accordingly, the four axes of the lower surface plate 1, the upper surface plate 2, the sun gear 6, and the internal gear 11 rotate independently of each other.

  As shown in FIG. 2, the work carrier 13 has a gear formed on the outer periphery, and meshes with the sun gear 6 and the internal gear 11. A workpiece holding hole for holding the workpiece 200 is formed in the workpiece carrier 13. Various work carriers 13 are prepared according to the work, and one work carrier 13 is formed with one work holding hole, or a plurality of work holding holes are formed. There is. In this embodiment, as will be apparent from FIG. 2, the work carrier 13 having four work holding holes will be described as an example. The description will be made assuming that a plurality of such work carriers 13 (five illustratively in this embodiment) are arranged. In this embodiment, 20 workpieces are arranged.

The upper surface plate elevating device 14 is arranged on the upper surface of the upper surface plate 2 and has a function of applying an elevating force in the direction of arrow a to the upper surface plate support shaft 15.
The upper platen support shaft 15 is configured to move in the upper platen lifting / lowering drive unit 14 and is connected to the universal joint 16 at the tip.

The universal joint 16 is provided between the upper surface plate support shaft 15 and the upper surface plate suspension plate 17 so that the upper surface plate suspension plate 17 is rotatable about the upper surface plate support shaft 15 as a rotation axis. The upper surface plate suspension plate 17 is supported so as to be movable in a three-dimensional direction.
The upper surface plate suspension plate 17 is a robust plate body, for example, a disk body having the same diameter as the upper surface plate 2.

  A plurality of upper surface plate connecting rods 18 are provided between the upper surface plate suspension plate 17 and the upper surface plate 2. These upper surface plate connecting rods 18 are provided on the circle at equal intervals when viewed from above. The upper surface plate connecting rod 18 is provided so as to stand in a substantially vertical direction with respect to the upper surface plate 2. The lower part of the upper surface plate connecting rod 18 is connected and fixed to the upper surface plate 2 with a bolt (not shown). The upper portion of the upper surface plate connecting rod 18 is connected and fixed to the upper surface plate suspension plate 17 with a bolt (not shown). As a result, the upper surface plate suspension plate 17, the upper surface plate connecting rod 18, and the upper surface plate 2 move together.

The pressure fluid supply device 19 is a device that supplies a fluid at a predetermined pressure, for example. And a predetermined pressure is given to the fluid in the pressure fluid discharge apparatus 21 mentioned later, and it maintains as a pressure fluid.
The supply tube 20 is a flow path connecting the pressure fluid supply device 19 and the pressure fluid discharge device 21, and sends the fluid to the pressure fluid discharge device 21. In the actual double-side polishing apparatus, the supply tube 20 is connected so as not to get entangled even when the upper surface plate suspension plate 17 is rotated, but various techniques can be used.

The pressure fluid discharge device 21 is filled with a pressure fluid and has a function of supplying a small amount of the pressure fluid. Details of the pressure fluid discharge device 21 will be described later.
The connection tube 22 flows the pressure fluid supplied from the pressure fluid discharge device 21. A plurality of connection tubes 22 (20 which is the same number as the workpiece in this embodiment) are connected to the pressure fluid discharge device 21.

  The fluid discharge hole 23 is connected to the other end of the connection tube 22, is provided so that the hole faces the lower surface of the upper surface plate 2, and supplies pressure fluid to the lower side of the upper surface plate 2. In particular, as shown in FIG. 2, the positioning control of the work carrier 13 is performed so that the center of the work 200 is below the fluid discharge hole 23. Here, since the fluid discharge hole 23 indicated by the dotted line in the plan view with the upper surface plate removed in FIG. 2 is “a hole formed in the upper surface plate 2”, it does not naturally remain in the plan view with the upper surface plate 2 removed. Actually, FIG. 2 shows an expected position. Although not shown, in addition to the fluid discharge hole 23, the upper surface plate 2 is provided with a slurry discharge hole separately to supply the slurry.

  Of these components, the lower surface plate 1, the upper surface plate 2, the lower surface plate receiver 3, the base portion 4, the support portion 5, the sun gear 6, the sun gear drive shaft 7, the upper surface plate drive drum 8, the drum drive shaft 10, and the internal gear 11 The rotation center axis of the internal gear support 12, the upper surface plate elevating device 14, the upper surface plate support shaft 15, the universal joint 16, and the upper surface plate suspension plate 17 is a common axis.

  Further, the rotation of the lower surface plate 1, the upper surface plate 2, the sun gear 6, and the internal gear 11 is controlled by the upper surface plate rotation driving unit, the lower surface plate rotation driving unit, the sun gear rotation driving unit, and the internal gear rotation driving unit, respectively. For example, optimal wrapping and polishing is performed by adjusting the rotation speed by a control device connected to each of these driving units. Moreover, although mentioned later, a control apparatus controls the position of the workpiece | work carrier 13 so that the fluid discharge hole 23 may be located above a workpiece | work. The double-side polishing apparatus 100 is like this.

  Next, sticking prevention by the pressure fluid discharge device 21 that characterizes the present invention will be described. First, the principle of sticking prevention will be examined with reference to FIG. Sticking when the work surface faces the upper surface plate 2 with good surface roughness is considered as a rheological problem. As shown in the model diagram of FIG. 3A, it is assumed that there is a liquid phase having a thickness H between the workpiece 200 having a width D and the upper surface plate 2 in a cross section. Although H is originally narrow in width, in FIG. 3A, H is broadly described for clarity. If the workpiece 200 is moved away from the upper surface plate 2 so as to be perpendicular to the workpiece surface, the liquid flows into the inside (center side) under a constant volume condition and becomes thinner. Assuming that the velocity of the liquid in the horizontal direction (inward) is V and the velocity H ′ that separates the workpiece, it can be expressed as follows:

[Equation 1]
V ≒ H '(D / H)

  Thereby (assuming that the horizontal velocity of the liquid is zero at the interface of the work surface), the velocity gradient γ 'of the inward flow is as follows.

[Equation 2]
γ '≒ V / H

  Further, when η is the viscosity of the liquid, a shear stress σ expressed by the following formula is given to the work surface.

[Equation 3]
σ = ηγ '

On the other hand, such a shear flow can be considered to be due to a pressure difference between the inside and the outside of the liquid sandwiched between the workpiece surfaces. Assuming that the atmospheric pressure P _{0 is} the pressure P at the center of the liquid, the following equation is established when viewed in a certain section.

[Equation 4]
H (P−P ₀ ) = − Dσ

  These are summarized as follows.

[Equation 5]
P−P ₀ = − {(D / H) ² } η (H ′ / H)

If F is a force for peeling the workpiece surface, F can be estimated as (P ₀ -P) D ² (here, the workpiece surface of D ² ). F is expressed by the following equation.

[Equation 6]
F = {(D / H) ³ } ηH′D

Here, F is a peeling force, η is a viscosity, D is a contact area, and H is an inclusion thickness. Thus, the force F is an equation depending on the speed H ′, the viscosity η, and (D / H) ³ and D. Incidentally, the viscous resistance force G when the workpiece plate is slid in parallel at the speed V is σ × D ² , and is substituted as shown in the following equation.

[Equation 7]
G = (D / H) ηVD

  Thus, the force G is considerably smaller than the force F described above. Therefore, if it is cut out in the direction parallel to the work surface as much as possible, it becomes easy to cut out. However, the presence of G still requires power to cut out. Therefore, in order to facilitate the cutting operation, the state of sticking between the upper surface plate and the workpiece is relaxed in advance (the thickness H of the fluid interposed on the contact surface of the workpiece is increased, the workpiece contact area D is increased). The primary separation is performed by reducing the viscosity η of the fluid.

  In order to avoid the sticking of the workpiece, in the present invention, the liquid layer thickness H is increased. That is, as shown in FIG. By sticking, the sticking force is greatly reduced. Here, the fluid to be supplied is a pressure fluid that is appropriately pressurized, and this pressure fluid is allowed to permeate the gap. Note that the pressure fluid to be discharged may be a very small amount. Further, in order to maintain the pressure high, intermittent discharge in which a pressure fluid having a sufficiently high pressure is output from only some of the fluid discharge holes is employed.

A fluid having a low viscosity is employed. The viscosity of water is 1.0 × 10 ⁻³ Pa · S, and the viscosity of air is 1.8 × 10 ⁻⁵ Pa · S. Thus, the viscosity of air is 1/50 or less of the viscosity of water, and it is clear that it is very effective to form an air layer at the interface with respect to the work attachment surface. Forming a thick air layer in this way leads to a reduction in the contact area D. It is also effective to form the water layer as thick as possible. In the present invention, air and water can be employed as the pressure fluid. In this embodiment, it is assumed that the fluid is a pressure fluid.

  Then, the discharge method of a pressure fluid is demonstrated. As described above, it is only necessary to flow the pressure fluid between the workpiece 200 and the contact interface of the upper surface plate 2 to form the fluid layer as thick as possible. Problem arises.

(1) Large equipment is required to discharge a large amount of pressurized fluid (air, water, etc.), and the cost is high.
(2) When a large amount of pressurized water is discharged as a pressure fluid, a large amount of staying water remains on the lower platen, which hinders the next process. At the same time, the workpiece on the lower platen floats and the workpiece pops out of the workpiece holding hole. appear.
(3) When a large amount of pressurized air is ejected as a pressurized fluid, the workpiece may be blown off toward the lower surface plate and may come off from the work holding hole of the work carrier. Pressurized air enters and floats each, and depending on the case, there is a concern that the work carrier or the work may stick to the upper surface plate again.
(4) Supplying a large amount of pressure fluid can be said to be a method of blowing off the work adhered to the upper surface plate with the energy of the fluid, and does not form an inclusion layer as thick as possible on the work interface.

On the other hand, when the flow rate of the pressure fluid is reduced as a whole, new problems due to the discharge fluid as described above can be prevented to some extent, and so much equipment is not necessary, but the following problems arise.
(A) In the step of peeling the workpiece 200 from the upper surface plate 2, a place where the workpiece 200 is stuck to the upper surface plate 2 and the flow path from the fluid discharge hole 23 is almost blocked, or the workpiece 200 and the upper surface plate 2. However, when pressure fluid is simultaneously discharged from a plurality of fluid discharge holes 23 under such circumstances, the pressure fluid is the latter. The fluid flows intensively to the location where the flow path exists, and the pressure of the fluid itself is reduced. At the same time, the fluid hardly flows to the place where the former flow path is blocked, that is, the interface of the workpiece 200 to be peeled off. Thus, the sticking prevention effect is insufficient.

  In the present invention, a small amount of pressure fluid is ejected from only one fluid discharge hole 23 at a time to suppress pressure reduction, and a peeling force by a pressure fluid having a sufficiently high pressure is applied to one workpiece 200. I tried to do it.

Then, for example, pressurized air is used as the pressure fluid, and a small amount of pressurized air is discharged from the fluid discharge hole 23 to form an air layer at the work interface.
In practical terms, depending on the discharge conditions of pressurized air, pressurized air may enter the interface between the lower surface plate and the workpiece or the work carrier, and the workpiece may adhere to the upper surface plate by floating the workpiece or carrier. There is concern that the workpiece will jump out of the carrier hole. Therefore, it is necessary to adjust the discharge conditions (pressure and flow rate) of the pressurized air.
In practical use, there is a concern that the workpiece surface may be dried. Therefore, a method of dropping water from the slurry supply port or measures such as intermittently supplying water into the upper cylindrical container may be used.

Further, for example, pressurized water may be employed as the pressure fluid, and the pressurized water may be discharged from the fluid discharge hole 23 to form a water layer at the work interface. Since it is an incompressible fluid, there is no problem of blowing off and drying at the time of applying pressurized air, so application is somewhat easy.
In this way, a pressurized fluid using pressurized air or pressurized water can be employed.

  Next, the configuration of the pressure fluid discharge device 21 will be described. 4 and 5, the pressure fluid discharge device 21 includes a device main body 211, a rod rotation motor 212, a fluid receiving port 213, a fluid discharge pipe 214, a rotation shaft 215, a bearing portion 216, a fluid reservoir portion 217, A swiveling rod 218, a hole 219, a sealing ball 220, a compression spring 221, and a flow path space 222 are provided.

Next, each configuration will be described.
As shown in detail in FIG. 5, the apparatus main body 211 further includes a bottom plate 211a, a middle plate 211b, a lid 211c, and a cylinder 211d, and a fluid reservoir that is partitioned by the middle plate 211b, the lid 211c, and the cylinder 211d. 217 is formed.
The rod rotation motor 212 is disposed on the upper side of the lid 211c of the apparatus main body 211, and is provided so that the rotation shaft 215 protrudes into the fluid reservoir 217 as shown in FIG.

The fluid receiving port 213 is disposed on the upper side of the lid 211 c of the apparatus main body 211 and communicates with the fluid reservoir 217. A supply tube 20 is connected to the fluid receiving port 213, and pressure fluid is received and sent to the fluid reservoir 217.
A plurality (20 in this embodiment) of fluid discharge pipes 214 are arranged on a cylinder 211d on the outer peripheral side of the apparatus main body 211. All the fluid discharge pipes 214 communicate with the fluid reservoir 217 through the flow path space 222.

The rotating shaft 215 is rotationally driven by a rod rotating motor 212. The rod rotation motor 212 and the rotation shaft 215 constitute the rotation drive unit of the present invention.
As shown in FIG. 5, the bearing portion 216 supports the rotating shaft 215 at two locations, ie, the upper lid 211c and the lower middle plate 211b, so that the rotating rotating shaft 215 does not shake. The bearing portion 216 also has a sealing function so that the pressure fluid does not leak.

The fluid reservoir 217 is a space where the fluid receiving port 213 communicates with the fluid discharge pipe 214 and is filled with pressure fluid.
The swivel rod 218 is pivotally supported by the rotating shaft 215 and rotates in the fluid reservoir 217 as shown in FIG. As will be described later, the rotating swivel rod 218 is in contact with the sealing ball 220 and pushes down the sealing ball 220.

The holes 219 are formed in the intermediate plate 211b, and when viewed from above, a plurality of holes (20 in this embodiment) are provided at equal intervals in the same circle as shown in FIG.
When the sealing ball 220 abuts the hole 219 communicating with the fluid reservoir 217 and closes the hole 219, the sealing ball 220 prevents pressure fluid from flowing into the flow path space 222 and the fluid discharge pipe 214, and when the sealing ball 220 moves away from the hole 219. Has a function of flowing the pressure fluid to the flow path space 222 and the fluid discharge pipe 214. The sealing ball 220 is disposed in a flow path space 222 that is a cylindrical housing portion.

The compression spring 221 urges the sealing ball 220 toward the hole 219, and the hole 219 is normally closed. The compression spring 221 is disposed in the flow path space 222 that is a cylindrical housing portion.
The channel space 222 is a cylindrical space. A sealing ball 220 and a compression spring 221 are disposed in the flow path space 222 to form a plunger type valve. A plurality (20 in this embodiment) of the plunger type valves are formed on a circle.

  As a feature of the pressure fluid discharge device 21 as described above, a multi-branch fluid distribution is realized by arranging ball plunger type valves on a circle and rotating the swivel rod 218. When position control is performed so that each fluid discharge hole 23 comes to approximately above the workpiece 200 at the end of machining, and a small amount of pressurized fluid (pressurized air or pressurized water) is injected, the pressure fluid is discharged from the dedicated fluid discharge hole 23. The workpiece 200 flows out between the workpiece 200 and the upper surface plate 2 to reduce the sticking force of the workpiece 200 so that the workpiece 200 is surely peeled off from the upper surface plate 2.

Next, the pressure fluid supply operation will be described.
First, as shown in FIG. 6A, the sealing ball 220 slightly protrudes from the hole 219 toward the fluid reservoir 217 and closes the hole 219. Then, it is assumed that the swivel rod 218 rotates and approaches the sealing ball 220.

  Then, as shown in FIG. 6B, when the swiveling rod 218 comes into contact with the sealing ball 220 and pushes it down, the pressure fluid filled in the fluid reservoir 217 is transferred to the sealing ball 220 and the hole 219. It flows from the gap. In the drawing, the state where the sealing ball 220 is moved away from the swivel rod 218 due to momentum is illustrated. This flowing time is a moment. A pressure fluid is caused to flow into the flow path space 222, and the fluid is discharged from the fluid discharge hole 23 through the fluid discharge pipe 214 and the connection tube 22.

  Then, as shown in FIG. 6C, after the swivel rod 218 is separated from the sealing ball 220, the sealing ball 220 is brought into contact with the hole 219 by the urging force of the compression spring 221, and the sealing state is restored. Then, the swivel rod 218 is rotated to open and close the ball plunger type valve in order.

  Such a pressure fluid discharge device 21 can instantaneously discharge a small amount of pressure fluid. Since each fluid supply path is independent and only one ball plunger valve is opened and pressure fluid is flowed, the pressure and amount of the pressure fluid filled in the fluid reservoir 217 are instantaneously reduced. Such a situation does not occur. Further, even when there is no workpiece, a large amount of pressurized fluid is not discharged, and a fixed amount is discharged.

  Further, since the pressure fluid is continuously supplied to the fluid reservoir 217 by the pressure fluid supply device 19, the original pressure does not decrease. Further, even if there is a gap between the fluid discharge hole 23 and the presence or absence of the workpiece 200, the supply amount is constant by the ball plunger type valve, and the original pressure does not decrease. Predetermined pressure and quantity are guaranteed even with a discharged pressure fluid.

  Then, if the pressure fluid is supplied to the center of the workpiece 200 as shown in FIG. 2, an appropriate amount of pressure fluid is permeated between the workpiece 200 and the upper surface plate 2 as shown in FIG. By forming the layer, the pasting force is greatly reduced instantaneously, and the workpiece 200 naturally falls downward due to its own weight. If the discharge amount of the pressure fluid is not excessive, a situation where the workpiece 200 is blown away does not occur. And such a function is implement | achieved cheaply by simple structure.

  Next, a series of processing operations including a specific workpiece picking operation of the double-side polishing apparatus 100 of this embodiment will be described. The double-side polishing apparatus 100 sandwiches the workpiece 200 held in the workpiece holding hole of each workpiece carrier 13 between the lower surface plate 1 and the upper surface plate 2 and causes each workpiece carrier 13 to perform a planetary motion while lowering the surface plate 1 and the upper surface plate. The platen 2 is rotated in opposite directions to perform polishing on both sides of the workpiece 200, and after the polishing is completed, the upper platen 2 is raised and the workpiece 200 is taken out.

(1) First, an installation step of installing the workpiece 200 on the workpiece carrier 13 is performed. In this installation step, for example, a plurality of workpieces 200 are mounted in the workpiece holding holes provided in the workpiece carrier 13 in a state where the upper surface plate 2 is lifted. For this mounting, manual mounting or mounting by a workpiece handling robot that automatically mounts the workpiece 200 on the workpiece carrier 13 and takes out the workpiece from the workpiece carrier 13 may be employed. A plurality of workpieces 200 to be wrapped or polished are held in the workpiece holding holes provided in the workpiece carrier 13.

(2) Subsequently, the upper surface plate 2 is lowered, and the rotational driving claw is fitted into the fitting groove of the upper surface plate driving drum 8 to constitute the connecting portion 9. A support load applied to the upper surface plate support shaft 15 is measured by a load meter (not shown), and the descent is stopped when the support load reaches a predetermined level.
The annular upper surface plate 2 supported by the upper surface plate support shaft 15 is driven to move up and down together with the upper surface plate support shaft 15, and is determined at a position where it contacts the workpiece 200 with an appropriate pressure.

(3) The lower surface plate 1 and the upper surface plate 2 are rotated to start processing.
When the upper surface plate rotation driving unit (not shown) rotates the drum drive shaft 10 and the upper surface plate driving drum 8 while starting the supply of the slurry from the slurry supply hole (not shown) provided in the upper surface plate 2, the connecting portion 9 Rotation of the upper surface plate 2 is started via
Although not shown, the slurry supply method itself employs a gravity drop method, and employs a very complicated and expensive method of providing pressure equipment and pumping or providing a flow control valve in each flow path. It is not a thing, but the cost reduction is realized also in this point.

  Similarly, the lower surface plate 1, the sun gear 6 and the internal gear 11 are also rotated at a predetermined speed. The lower surface plate 1 receives a driving force from the lower surface plate rotation driving unit and rotates in accordance with the driving force. The sun gear 6 is rotationally driven by the sun gear rotational drive unit, and the internal gear 11 is rotationally driven by the internal gear rotational drive unit. The tooth surface on the outer periphery of the work carrier 13 meshes with the sun gear 6 and the internal gear 11, and the work carrier 13 starts planetary motion. By rotating the sun gear 6 and the internal gear 11, the work carrier 13 on which the work 200 sandwiched between the upper surface plate 2 and the lower surface plate 1 is revolved while rotating, and both surfaces of the work 200 are polished.

  The rotation of the upper surface plate 2, the lower surface plate 1, the sun gear 6, and the internal gear 11 is controlled by the upper surface plate rotation driving unit, the lower surface plate rotation driving unit, the sun gear rotation driving unit, and the internal gear rotation driving unit, respectively. For example, optimal wrapping and polishing is performed by adjusting the rotation speed by a control device connected to each of these driving units.

(4) Stop processing after processing for a predetermined time.
When the workpiece 200 reaches the target thickness and a machining end signal is output from a thickness sensor (not shown) to the control device, the control device simultaneously adjusts the operation amount so that the workpiece carrier 13 can be stopped at the shortest distance to the stop position. Generate and enter stop operation. The stop position after machining of each workpiece is set to a fixed position. Therefore, positioning control of the sun gear 6 and the internal gear 11 for positioning the work carrier is performed. Similarly, the upper surface plate 2 generates an operation amount for positioning the shortest operation in which the fluid discharge hole 23 comes to each carrier position at a position corresponding to each workpiece (post-processing stop position). Enters stop operation to perform rotational positioning.

  When positioning the upper surface plate 2 immediately before or after the work processing is completed, it is necessary to minimize the movement of the upper surface plate 2 to prevent the workpiece 200 from being excessively polished or scratched. Since the fluid discharge hole 23 on the platen 2 is similarly provided at a position corresponding to each work carrier 13 around the center axis of the platen (360 degrees / number of work carriers n), the amount of rotation of the upper platen 2 The above-described problem can be avoided by matching the positions of the fluid discharge hole 23 and the work carrier 13 at the rotational position with the least number of rotations. This (4) corresponds to the first step of the present invention.

(5) A sticking prevention process is performed.
When the upper surface plate 2, the lower surface plate 1, and the work carrier 13 are stopped at predetermined positions, the upper surface plate is raised while performing the “sticking prevention step”. Specifically, as described above, the swiveling rod 218 of the pressure fluid discharge device 21 rotates and the ball plunger type valve is sequentially depressed to intermittently supply the pressure fluid from each fluid discharge hole 23, and all the workpieces 200. Giving peeling force against.

(6) Raise the upper surface plate 2 at a slow speed.
At this time, if the upper surface plate 2 has no special posture holding mechanism, the peeling proceeds from the work surface at an arbitrary position. (Strictly speaking, the upper surface plate 2 is slightly inclined) At this time, the upper surface plate 2 is in a state in which a portion separated (separated) from the workpiece 200 and a portion in contact with the workpiece 200 are mixed. After a while, the workpiece 200 is separated (separated) from the upper surface plate. These (5) and (6) correspond to the second step of the present invention.

(7) When the upper surface plate 2 rises to a certain amount of height, the ascent speed is increased to raise the upper limit of the retreat position.

(8) The workpieces 200 on the lower surface plate 1 are sequentially collected automatically or manually. These (7) and (8) correspond to the third step of the present invention.
The machining operation is like this.

  According to such a double-sided processing apparatus 100, since a very small amount of pressure fluid is allowed to flow between the upper surface plate 2 and the workpiece 200, the sticking force is greatly reduced to facilitate peeling. In particular, a very small amount of pressure fluid can be discharged by the pressure fluid discharge device 21 having a simple configuration.

Next, another embodiment of the present invention will be described. Compared with the swivel rod 218 of the pressure fluid discharge device 21 described with reference to FIGS. 1, 2, 2, 3, 4, 5, and 6, the width of the swivel rod is increased in this embodiment. In FIG. 7A of the previous form shown for comparison, the width of the swivel rod 218 is narrow, but this embodiment is different only in that the width of the swivel rod 218 is increased as shown in FIG. 7B. Yes. Others adopt the same configuration and have the same description as the previous embodiment, and redundant description is omitted.
That is, the time for the swivel rod 218 to contact the sealing ball 220 is lengthened, and the amount of fluid flowing in increases. Such a configuration may be adopted. At this time, if the rotational speed is adjusted, the increase or decrease of the fluid flowing in can be adjusted.

  Next, another embodiment of the present invention will be described. In the pressure fluid discharge device 21 described above with reference to FIGS. 4 and 5, all the plunger type valves are arranged on one circle. In this embodiment, as shown in FIG. 8, all plunger type valves are arranged on two concentric circles. Two plunger-type valves are arranged at the same angle. Accordingly, the swiveling rod 218 comes into contact with the second plunger type valve at a certain angle to flow the pressure fluid, and the time can be shortened and more fluid discharge holes 23 can be employed. As described above, the pressure fluid discharge device 21 can be configured even if the plunger type valve is increased. At this time, if the rotational speed is adjusted, the increase or decrease of the fluid flowing in can be adjusted. Thus, even when the number of the fluid discharge holes 23 increases, the holes 219 can be arranged in a plurality of rows, or can be arranged by adjusting the installation interval of the plunger type valves. Further, as described in the previous embodiment, the width and the like of the swivel rod 218 are appropriately set, and the discharge time and flow rate from each fluid discharge hole 23 can be arbitrarily set. Such a configuration may be adopted.

  Next, another embodiment of the present invention will be described. In the previous embodiment, one fluid discharge hole 23 is arranged for one workpiece 200. However, in order to more reliably peel the workpiece 200, two fluid discharge holes 23 may be provided for one workpiece 200 as shown in FIG. Further, the positions of the two fluid discharge holes 23 are both provided on the outer peripheral side away from the center of the work so that the pressure fluid can easily spread over the entire surface. In this embodiment, there are 20 workpieces, and a total of 40 fluid discharge holes 23 are provided. Forty fluid discharge holes 23 and 40 connection tubes 22 are also provided. Here, since the fluid discharge hole 23 indicated by the dotted line in the plan view with the upper surface plate removed in FIG. 9 is “a hole formed in the upper surface plate 2”, it does not naturally remain in the plan view with the upper surface plate 2 removed. Actually, FIG. 9 shows an expected position. By adopting such a configuration, the pressure fluid is discharged to a wide area between the upper surface plate 2 and the workpiece 200, and the workpiece 200 is more easily peeled off. In addition, the form demonstrated using FIG. 4, FIG. 5 may be employ | adopted for the pressure fluid discharge apparatus 21, and the form demonstrated using FIG. 7, FIG. 8 may be employ | adopted. Such a form may be adopted.

  Next, another embodiment of the present invention will be described. In the previous embodiment, two fluid discharge holes 23 are arranged for one workpiece 200. However, in order to more reliably peel the workpiece 200, three fluid discharge holes 23 may be provided for one workpiece 200 as shown in FIG. Further, the positions of the three fluid discharge holes 23 are also provided on the outer peripheral side apart from the center of the work so that the pressure fluid can easily spread over the entire surface. In this embodiment, there are 20 workpieces, and a total of 60 fluid discharge holes 23 are provided. 60 fluid discharge holes 23 and connection tubes 22 are also provided. Here, the dotted line fluid discharge hole 23 in the plan view with the upper platen removed in FIG. 10 is “a hole formed in the upper platen 2”, so it does not naturally remain in the plan view with the upper platen 2 removed. Actually, FIG. 10 shows an expected position. By adopting such a configuration, the pressure fluid is discharged to a wide area between the upper surface plate 2 and the workpiece 200, and the workpiece 200 is more easily peeled off. In addition, the form demonstrated using FIG. 4, FIG. 5 may be employ | adopted for the pressure fluid discharge apparatus 21, and the form demonstrated using FIG. 7, FIG. 8 may be employ | adopted. Such a form may be adopted.

  Further, although not shown, in a large-diameter workpiece in which one workpiece is fitted in one workpiece carrier, one fluid discharge hole is provided at the center position of the workpiece, and three or four on the circumference having a predetermined radius from the center. The fluid discharge hole may be provided. However, it is necessary to consider the number and arrangement of the discharge holes as appropriate depending on the state of the workpiece. By comprising in this way, it can peel off efficiently.

In such a double-side polishing apparatus of the present invention, since a plurality of fluid discharge holes are arranged on the center of the workpiece or on a circumference having a predetermined radius from the center of the workpiece, pressure fluid is generated between the upper surface plate and the workpiece. It is reliably discharged and a peeling force is reliably applied. Then, the minimum number of fluid discharge holes may be provided in consideration of the actual product such as the arrangement of the fluid discharge holes and the material and thickness of the workpiece to be used.
Moreover, it is only necessary to add a relatively simple and inexpensive configuration such as a pressure fluid discharge device, a connection tube, and a fluid discharge hole, and a significant cost reduction is realized as compared with the conventional technology using many flow control valves. .

Further, the double-side polishing apparatus of the present invention only consumes a small amount of compressed air or water, which is a utility normally provided in the factory, as a pressure fluid, not an expensive slurry, and the cost is also increased to a minimum. Stay on.
Further, the double-side polishing apparatus of the present invention is not difficult to wash like slurry, and only discharges a small amount of pressurized fluid intermittently, so that the influence on the subsequent process including the work surface is reduced.
Further, since the pressure fluid is very small, it prevents a situation where it is blown away like a large amount of pressurized air or flows like a large amount of pressurized water.
Moreover, since the pressure of the pressure fluid that exits from all the fluid discharge holes can be maintained almost constant regardless of the presence or absence of a workpiece, a constant peeling force can be applied, and convenience is enhanced.

Moreover, the double-side polishing apparatus of the present invention is effective in both lapping and polishing, and is highly convenient.
In addition, the double-side polishing apparatus of the present invention has advantages of high efficiency, no environmental deterioration, and low cost because pressurized air or pressurized water is used as the pressure fluid. In addition, it is preferable to use pressurized air from the viewpoint of not staining the surface plate.

  As described above, the double-side polishing apparatus of the present invention can be implemented simply and at low cost without major modifications to the conventional equipment, and further, measures are taken so as not to adversely affect the conventional processing process. In addition, by simply adding a simple configuration, a peeling force is applied by supplying a very small amount of fluid to reliably prevent the workpiece from sticking to the upper surface plate, eliminating the need for return work and cleaning work. A double-side polishing apparatus and a polishing method that improve continuity can be provided.

  The above-described double-side polishing apparatus and polishing method according to the present invention are particularly suitable for polishing a workpiece such as a silicon wafer or a transparent glass substrate.

100: Double-side polishing apparatus 1: Lower surface plate 2: Upper surface plate 3: Lower surface plate receiver 4: Base portion 5: Support portion 6: Sun gear 7: Sun gear drive shaft 8: Upper surface plate drive drum 9: Connecting portion 10: Drum drive Shaft 11: Internal gear 12: Internal gear support 13: Work carrier 14: Upper surface plate lifting device 15: Upper surface plate support shaft 16: Universal joint 17: Upper surface plate suspension plate 18: Upper surface plate connecting rod 19: Pressure Fluid supply device 20: Supply tube 21: Pressure fluid discharge device 211: Device main body 211a: Bottom plate 211b: Middle plate 211c: Lid 211d: Cylinder 212: Rod rotation motor 213: Fluid receiving port 214: Fluid discharge pipe 215: Rotating shaft 216: Bearing 217: Fluid reservoir 218: Swivel rod 219: Hole 220: Sealing ball 221: Compression spring 222: Channel space 22: Connection tube 23: Body discharge hole

Claims (3)

In a double-side polishing machine that wraps or polishes both the front and back surfaces of the workpiece with the upper and lower surface plates,
An appropriate number of fluid ejection holes provided on the lower surface of the upper surface plate, each of which is provided at a position corresponding to the stop position of each workpiece after the polishing process,
A pressure fluid discharge device for intermittently discharging a pressure fluid from the fluid discharge hole onto the upper surface of the work in small amounts;
A double-side polishing apparatus characterized in that a pressure fluid is allowed to flow between the lower surface of the upper surface plate and the workpiece. The pressure fluid discharge device comprises:
A fluid reservoir filled with pressure fluid, a plurality of holes formed on a circle at openings of a plurality of flow passage spaces communicating with the fluid reservoir, and a sealing ball pressed against the hole A plurality of ball plunger type valves provided in the respective flow path spaces, and provided in the fluid reservoir, and the fluid reservoir by pushing the sealing ball for a predetermined period by rotational movement. A swivel rod that communicates with the flow path space, and a rotation drive unit that rotationally drives the swivel rod,
The revolving rod pushes the sealing ball and sequentially supplies a small amount of pressurized fluid to the flow passage space through the gap, and the pressure fluid is supplied to each fluid discharge hole on the upper surface plate through the plurality of flow passage spaces. 2. The double-side polishing apparatus according to claim 1, wherein the double-side polishing apparatus is adapted to discharge. After the workpiece polishing process is completed, the workpiece is moved to a predetermined position where each workpiece is taken out, and the upper surface plate is moved to a position corresponding to the stop position of the workpiece to position each fluid discharge hole on each workpiece. A first step;
A second step of operating the pressure fluid discharge device and simultaneously raising the upper surface plate at a low speed;
After raising the upper platen by a predetermined amount, stop the operation of the pressure fluid discharge device, raise the upper platen from medium speed to high speed and reach the predetermined position, then work on the lower platen sequentially A third step to be taken out;
A method for polishing a workpiece comprising the steps of:

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