JP2006035369A - Surface polishing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a surface polishing machine capable of simultaneously machining a plurality of workpieces while holding the extremely thin workpieces in the surface polishing machine provided with a plurality of rotation bodies meshed with a sun gear and an internal tooth gear and rotated while holding the workpieces integrally, and a platen rotated while abutting on the polished surfaces of the workpieces held by the rotation bodies. <P>SOLUTION: The rotation body 4 is provided with a negative pressure region, and a micro-porous holding plate 17 formed of ceramic is provided to cover the negative pressure region. A pipe 16 connected to a transforming means capable of decompressing the negative pressure region is piped in communication with the negative pressure region 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a flat polishing machine, and more particularly to a flat polishing machine suitable for polishing an extremely thin substrate or the like.

  Conventionally, small-sized microchips have been targeted as workpieces that require high-precision planar polishing, but in recent years IC packages (TAB, lead frames), thermal print heads, FDPs, build-up substrates Photomask materials such as (MCM, BGA), FDP, mother glass for PDP.LCD, ITO electrode mask materials, etc. are becoming targets.

  In particular, a liquid crystal panel (hereinafter referred to as a cell) composed of a color filter substrate (hereinafter referred to as CF) which is a display unit and an array substrate (hereinafter referred to as TFT) for the purpose of reducing the thickness and weight of the liquid crystal display device. Is required to be made extremely thin.

  As technical means for making the cell extremely thin, there are a chemical etching method and a machining method. In the chemical etching method, a glass substrate constituting the substrate is dissolved using hydrofluoric acid or the like. The machining method includes mechanical polishing and mechanical grinding. In the case of mechanical polishing, both sides or one side of the cell are processed by using loose abrasive grains. In the case of mechanical grinding, the processing is reduced on one side of the cell with a fixed grindstone.

  Compared with the chemical etching method, the machining method has a better thickness accuracy and is more advantageous than the chemical etching method in terms of environmental measures and safety, and is becoming popular. As a means for polishing these plate-like substrates by a processing method by mechanical polishing, for example, a carrier meshed with a sun gear and an internal gear, and integrally rotating the workpiece, and a workpiece covered by the carrier. There is a plane polishing machine provided with a surface plate that is rotated while being in contact with the polishing surface (see, for example, Patent Document 1).

  The surface polishing machine shown in this patent document is a double-side polishing machine, and the carrier for holding the workpiece is made of a gear having teeth formed on the outer periphery, and the workpiece penetrates in accordance with the outer diameter of the workpiece. A hole, in this example, is a square through hole, and a workpiece is fitted into this hole. The thickness of the carrier corresponding to the thickness of the gear is made thinner than the thickness of the workpiece by a dimension that includes a margin for the grinding allowance.

  A sun gear and an internal gear are provided on a disk-shaped lower surface plate so that the center of rotation is aligned with the center of rotation of the lower surface plate, and a plurality of carriers are provided so as to mesh with the sun gear and the internal gear in common. The carrier has a through hole for the work, and the work is fitted on the opening and held on the lower surface plate by its own weight.

  Thus, the lower surface plate contacting the lower surface of the work is provided so as to be rotatable about the rotation center common to the center of the internal gear. The upper surface plate is provided so as to be movable in the up and down direction and is rotationally driven so as to face the lower surface plate. During polishing, the upper surface plate contacts the workpiece with a predetermined polishing pressure and rotates. At the same time, an abrasive is supplied between the workpiece and the upper and lower surface plates. As the carrier rotates and revolves around the sun gear, the work moves relative to the upper and lower surface plates, and both surfaces of the work are ground.

  Conventionally, the workpiece is held through the carrier, and in such a system, the thickness of the carrier is a condition for polishing that is thinner than the thickness of the workpiece by a margin for the polishing allowance. Otherwise, the upper surface plate comes into contact with the carrier before it comes into contact with the workpiece, and the workpiece is not polished.

  Explaining with drawings, as shown in FIG. 7, the workpiece W6 is held by the carrier C3 in a state of penetrating the carrier C3, and the carrier C3 and the workpiece W6 ride on the lower surface plate J2 under their own weight, and the workpiece W6. The upper surface plate J1 touches from above. Symbol U1 indicates an internal gear. OO represents a common rotation center of the sun gear S1, the upper surface plate J1, the lower surface plate J2, and the internal gear U1. The carrier C3 revolves around the sun gear S1, and the upper surface plate J1 and the lower surface plate J2 rotate about the rotation center OO to polish both surfaces of the workpiece W6.

  In the configuration in which the workpiece is held by such a carrier, there is an advantage that the plurality of carriers C3 can be disposed around the sun gear S1 so that the surface of the workpiece can be polished at the same time as the number of carriers. In the holding method in which the thin film is held through, a workpiece thinner than the thickness of the carrier cannot be polished, so there is a limit to the planar polishing of an ultra-thin workpiece required for the plate-like substrate in recent years.

  The trend of thinning the cell as a workpiece is remarkable, and until several years ago, the thickness was 1.0 mm, but last year production of 0.8 mm and 0.6 mm was started at present. 0.3 mm processing is also expected. However, in order to perform such polishing with a conventional carrier, the thickness of the carrier must be smaller than the thickness of these cells, but the carrier is a gear and can transmit a rotational force. Since strength is required, it is difficult to realize with such a thin thickness.

  On the other hand, as a single-side polishing machine that employs a work holding method that is not a carrier penetration type, there is a thin plate polishing machine that includes a holding plate having a through hole connected to a vacuum pump (for example, see Patent Document 2). In this method, the workpiece is vacuum-sucked to the holding plate, but a slight gap is generated between the workpiece and the holding plate due to the roughness of the contact surfaces of both, so that the abrasive is passed through this gap. There is a problem that the suctioned water is sucked into the through hole and the polishing head, the moisture in the sucked abrasive is evaporated and solidified, and a part of it is scattered and adheres to the work holding surface of the holding plate. Therefore, it is necessary to provide a cleaning facility for ejecting liquid from the through hole. In addition, the holding plate is of a type that is directly connected to a drive source and is driven to rotate, and is not a method of simultaneously processing a plurality of workpieces by rotating a plurality of carriers at the same time, so there is a problem in terms of production efficiency.

  There is also a method of adsorbing and fixing a workpiece on an elastic resin sheet using surface tension as an adsorption plate for single-side polishing. However, when applied to an extremely thin workpiece, the polishing load is delicate during processing. If the platen flatness or parallelism is large, uniform pressure is not applied to the entire surface of the work, resulting in uneven deformation of the suction plate, resulting in increased thickness variation of the work. The suction plate is easily deteriorated, and the degree of deterioration is not necessarily uniform depending on the location, and varies depending on the location. Therefore, the sinking amount of the suction plate due to the polishing load changes, and the thickness of the workpiece varies.

JP-A-8-174408 JP-A-9-962956

  The present invention has been made in view of the background of the prior art described above, and an object of the present invention is to provide a planar polishing machine capable of simultaneously processing a plurality of workpieces while holding an extremely thin workpiece.

The present invention has the following configuration in order to achieve the above object.
(1) The invention according to claim 1 includes a plurality of rotating bodies that rotate while holding the workpiece integrally, and a surface plate that is rotated while contacting the surface to be polished of the workpiece held by these rotating bodies. In the planar polishing machine, the rotating body is provided with a fine porous holding plate made of ceramic that is provided integrally with the rotating body and arranged on the opposite side of the work holding surface in the negative pressure region as means for holding the work. It was decided to have.
(2) In the invention described in claim 2, a plurality of rotating bodies meshed with the sun gear and the internal gear and rotating while integrally holding the workpiece, and a surface to be polished of the workpiece held by these rotating bodies In a surface polishing machine having a surface plate that is rotated while in contact with the rotating body, the rotating body is provided with a negative pressure region, and a fine porous holding plate made of ceramic is provided so as to cover the negative pressure region. The negative pressure region is connected to a transformer that can reduce the negative pressure region.

  In the surface polishing machine according to claim 2, the rotating body is made of a disk-shaped gear, and a frame-shaped step portion is provided on an inner wall portion of a concave hole formed on one surface thereof. An edge portion of the fine porous holding plate was fitted and fixed to the stepped portion, and a communication port communicating with the transforming means was formed in the hole closed by the fine porous holding plate.

  4. The surface polishing machine according to claim 1, wherein the rotating body meshes with the sun gear and the internal gear in common and revolves around the sun gear. 5. The planar polishing machine according to claim 1, wherein the transformer means can depressurize the negative pressure region and release the depressurized pressure. 6. The planar polishing machine according to claim 1, wherein the fine porous holding plate is a porous ceramic (trade name: adsorption plate manufactured by Mitsui Mining & Materials Co., Ltd.).

  According to the present invention, since the work is adsorbed to the ceramic microporous holding plate provided on the plurality of rotating bodies, it is possible to simultaneously process a plurality of workpieces, and the work is adsorbed via the ceramic microporous holding plate. It is held stably.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  In FIG. 1, a hole having a stepped inner diameter is formed in the main body 1 of the surface polishing machine, and the uppermost stepped portion of this hole has an L-shaped cross section, and the overall shape is a ring-shaped bearing. 2 is installed. A ring-shaped internal gear 3 is fitted and supported on the inner peripheral portion of the bearing 2.

  The external appearance of the internal gear 3 is shown in FIGS. Three rotating bodies 4 are provided so as to mesh with the internal teeth of the internal gear 3. These three rotators correspond to conventional carriers and are arranged at equal intervals on the circumference of the inner teeth. Since these three rotators have a common shape structure, the following description will be given focusing on an arbitrary one.

  In FIG. 1, a ring-shaped fixed surface plate 5 on which a part of each of three rotating bodies 4 is placed is fitted and fixed in a stepped hole of a main body 1. The rotation center of the internal gear 3 and the center axis of the fixed surface plate 5 are common, and this is indicated by the center axis O1-O1. A lower rotation shaft 6 is provided with the center of rotation aligned with the center axis O1-O1. The lower part of the lower rotary shaft 6 is supported by the main body 1 by a bearing 7, and the intermediate part of the lower rotary shaft is supported by the main body 1 through bearings 8 and 9 described later.

  A sun gear 10 is fixed to the upper end portion of the rotating shaft 6, and a disk-shaped rotating platen 11 is fixed to the lower portion of the sun gear 10. The upper surface of the fixed surface plate 5 and the upper surface of the rotating surface plate 11 are assembled so as to be at the same level. The three rotating bodies 4 described above mesh with the internal teeth of the internal gear 3 as described above, and also mesh with the sun gear 10.

  A pulley 12 is fixed to the lower portion of the rotating shaft 6, and a belt 15 is wound between the pulley 12 and a pulley 14 of a motor 13 attached to the main body 1. Thereby, when the motor 13 rotates, the rotating shaft 6 is rotated via the belt 14, and the rotating surface plate 11 and the sun gear 11 rotate integrally. The rotating body 4 rides on the fixed surface plate 5 and the rotating surface plate 11 in common with its own weight, and the sun gear 10 slides on each surface of the rotating surface plate 11 and the fixed surface plate 5 by the rotation of the sun gear 11. Revolve while spinning around.

  In FIG. 4 showing an exploded view of the rotating body 4 and FIG. 5 showing a cross section of the rotating body 4, the rotating body 4 is a gear having teeth formed on the outer periphery thereof, and the upper surface thereof is matched to the outer shape of the workpiece. The bottomed hole 16 that forms the negative pressure region having a rectangular shape, in this example, is formed. The bottom of the bottomed hole is denoted by reference numeral 16a, and a step portion formed in a frame shape at a middle portion in the depth direction of the bottomed hole 16 is denoted by reference numeral 16b.

  A fine porous holding plate 17 made of a rectangular plate-like ceramic is fitted and fixed to the step portion 16b using the step portion. The fine porous holding plate 17 has a fine porous structure in which innumerable fine holes are formed in communication with the entire communication outer peripheral surface, and the hole diameter is several tens of μm. As shown in FIG. 1, the upper surface of the microporous holding plate 17 attached and fixed to the rotating body 4 is attached at the same level as or slightly higher than the upper surface of the rotating body 4.

  The microporous holding plate 17 is formed slightly smaller than the workpiece W2 so that the entire surface of the workpiece W2 to be processed can be in close contact. A guide plate 18 having a guiding function is fixed to the upper surface of the rotating body 4 so that the workpiece W2 is correctly placed on the fine porous holding plate 17. An opening 18a is formed in the guide plate 18 according to the contour of the workpiece W2.

  As shown in FIG. 3, since the guide plate 18 is fixed to the upper surface of the rotating body 4 in advance, the operator uses the workpiece W2 as a guide for the opening 18a of the guide plate 18 and holds the workpiece W2 as a fine porous holding plate. 17 can be mounted.

  In FIG. 6 that shows the microporous holding plate 17 and the work W2 in an enlarged manner in FIG. 1, the upper surface of the microporous holding plate 17 has the work W2 mounted thereon, and constitutes the holding surface of the work W2. The surface opposite to the workpiece holding surface, that is, the lower surface faces the bottomed hole 16.

  The internal space portion of the bottomed hole 16 in which the lower surface of the microporous holding plate 17 is disposed constitutes a negative pressure region. 5 and 6, a pipe 19 is attached to the bottom 16a via a bearing 20. By sucking air from the pipe 19, the space portion of the bottomed hole 16 can be set to a negative pressure. In a negative pressure state, the workpiece W2 is held in close contact with the fine porous holding plate 17 and integrated with the rotating body 4.

  Here, as described above, since the rotating body 4 revolves while rotating around the sun gear 10, it is necessary to devise in order to connect the pipe 20 to a vacuum pump or the like. In this example, as shown in FIG. 1, by providing a difference in diameter between the inner diameter portion of the fixed surface plate 5 and the outer diameter portion of the rotating surface plate 11, a ring-shaped space 22 centered on the rotation center O1-O1 is formed. The pipes 19 are arranged in the ring-shaped space 22, and the tip side of each pipe is communicated with the hollow portion 21 a of the flange 21 supported by the bearing 8. The outer peripheral portion of the flange 21 is supported by the main body 1 through the bearing 9 described above.

  Here, two bearings 9 are provided at an interval in the vertical direction, and a space portion 23 formed by the interval is communicated through a communication hole 24 formed on a side portion of the flange 21. The space 23 is connected to the pipe 26 through a communication hole 25 formed in the main body 1.

  The extension destination of the pipe 26 is connected to a transformer that can reduce the negative pressure region. This transformer means is a vacuum pump. Or it is a vacuum tank decompressed by a vacuum pump. A switching valve is provided in the pipeline of the pipe 26 so that the negative pressure state can be released. In addition to the negative pressure state, when the work W2 is taken out, the pressure tank can be connected to a pressure tank so that the pressure can be increased. Like that. Such means are collectively referred to as transformer means. The work W2 can be easily attached and detached by the transformer means.

  1 to 3, an upper surface plate 27 sized to cover the fixed surface plate 5 is provided. The upper surface plate 27 is provided with a number of supply pipes 28 for supplying a liquid abrasive between the workpiece W2 and the surface plate (upper surface plate 27, fixed surface plate 5, rotating surface plate 11).

  A flange 29 is positioned above the upper surface plate 27 with a space therebetween, and the upper surface plate 27 and the flange 29 are integrated by a connecting member 30. Both the upper surface plate 27 and the flange 29 have a disk shape, and these are fixed to a common shaft 31. The shaft 31 is concentric with the rotation center O1-O1.

  A ring-shaped storage tank 32 centering on the rotation center O1-O1 is fixed to the upper surface of the flange 29. The storage tank 32 has a concave cross-sectional shape, and an abrasive is supplied from the supply pipe 33 to the concave portion. Since the bottom of the storage tank 32 communicates with the supply pipe 28, the abrasive supplied to the storage tank 32 reaches the entire area of the circular storage monkey 32 or is arranged around the entire circumference of the circular storage tank. Through the supply pipe 28 thus supplied, it is supplied to the polishing part (sliding part) of each workpiece W2 of the three rotating bodies 4.

  The upper surface plate 29 is rotationally driven in accordance with the configuration of a known surface polishing machine, and can be moved up and down using a hydraulic mechanism or the like. Since the workpiece W2 is polished one side at a time, the upper platen is raised by a required amount when turning over after completion of one side, taking out after double-sided polishing, and mounting. The descent is precisely controlled so that

  In this example, a fine porous holding plate made of a highly durable material such as ceramics and having a fine countless number of pores of several tens of μm is integrally provided on the rotating body, and the workpiece is made fine using negative pressure. Unlike the conventional carrier in which the workpiece penetrates the rotating body, the rotating body has no problem in polishing an extremely thin workpiece even if the thickness is increased. It becomes possible to polish the workpiece.

  During polishing, the workpiece W2 is in close contact with the fine porous holding plate 17, the suction of the abrasive is not performed, the fine holes are not clogged with the abrasive, and a cleaning device is not necessary. In addition, the work can be reversed and taken out easily by attaching and pressurizing the work by depressurizing the negative pressure region by the transformer.

The rotating body 4 meshes with the sun gear 10 and the internal gear 3 in common and revolves around the sun gear 10, and the surface to be polished of the work is rubbed with a sweep locus different from that of the surface plate, thereby improving the polishing accuracy. I was able to. Since the transformer means can reduce the negative pressure region and release the reduced pressure to increase the pressure, the workpiece can be easily attached and detached. The fine porous holding plate (Mitsui Mining Materials Co., Ltd., trade name: adsorption plate) can be used to polish well over time without introducing an abrasive into the micropores and without taking any special cleaning measures. Conditions can be maintained.
Although the present invention has been described by taking a cell as a workpiece, the present invention is not necessarily limited to the cell, and can be applied to various shapes such as a silicon wafer and a sapphire substrate.

It is principal part sectional drawing of a plane grinder. It is a principal part disassembled perspective view of a plane grinder. It is the perspective view explaining the state which spaced apart the upper surface plate from the workpiece | work. It is a disassembled perspective view of the rotary body when a workpiece | work is mounted | worn. It is a partial cross section perspective view of a rotary body. It is sectional drawing explaining the assembly state of a rotary body, a fixed surface plate, a rotation surface plate. It is explanatory drawing of a prior art.

Explanation of symbols

4 Rotating body 17 Fine porous holding plate W2 Workpiece

Claims (6)

In a planar polishing machine comprising a plurality of rotating bodies that rotate while holding the work integrally, and a surface plate that is rotated while contacting the surface to be polished of the work held by these rotating bodies,
The rotating body is provided with a fine porous holding plate made of ceramic, which is provided integrally with the rotating body and arranged on the opposite side of the work holding surface in a negative pressure region as means for holding the work. Polishing machine. A plurality of rotating bodies that mesh with the sun gear and the internal gear and integrally rotate the workpiece, and a surface plate that rotates while contacting the surface to be polished of the workpiece held by these rotating bodies. In the plane polishing machine
The rotating body is provided with a negative pressure region, and a fine porous holding plate made of ceramic is provided so as to cover the negative pressure region, and the negative pressure region may be decompressed. A planar polishing machine, characterized in that it is connected to a transforming means that can be used. In the surface polishing machine according to claim 2,
The rotating body is made of a disc-shaped gear, and a frame-shaped step is provided on the inner wall portion of a concave hole formed on one side of the gear, and the step of the fine porous holding plate is provided on the step. A planar polishing machine characterized in that an edge portion is fitted and fixed, and a communication port communicating with the transformation means is formed in the hole closed by the fine porous holding plate. In the plane polishing machine according to any one of claims 1 to 3,
A surface polishing machine characterized in that the rotating body meshes with a sun gear and an internal gear in common and revolves around the sun gear. In the surface polishing machine according to any one of claims 1 to 4,
The planar polishing machine according to claim 1, wherein the transformer means can depressurize the negative pressure region and release the depressurized pressure. In the surface polishing machine according to any one of claims 1 to 5,
The surface polishing machine, wherein the fine porous holding plate is a porous ceramic (trade name: adsorption plate manufactured by Mitsui Mining & Materials Co., Ltd.).

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