JPH0671689B2 - Vacuum suction device for polishing and grinding - Google Patents

Description

The present invention relates to holding of a workpiece to be ground or ground, and is particularly suitable for polishing or grinding a workpiece having a large diameter with high shape accuracy. The present invention relates to a vacuum suction device for polishing and grinding.

[Conventional technology]

Conventionally, as a means for holding a workpiece by vacuum suction, for example, as shown in Japanese Utility Model Laid-Open No. 59-17159, as a means for preventing suction of abrasives to the vacuum chuck suction surface, it is slid on the outer peripheral portion of the vacuum chuck. There is known a device in which a movable seal body is provided and the seal body is vacuum-sucked to the outer periphery of the back surface of the wafer.

This device can prevent the suction of the abrasive on the vacuum chuck surface, but only the sliding seal body portion is brought into close contact with the wafer, and the wafer is not subjected to the grinding pressure.

Further, for example, as shown in Japanese Utility Model Application Laid-Open No. 58-40338, a thin film-like soft plastic sheet is formed on the upper surface of the vacuum suction member, in which thin holes are formed to connect to the small holes penetrating the suction table. It is known that a large number of striations connecting to the fine holes are formed on the contact surface of the upper surface wafer of the sheet. This device simply allows the wafer to be removed in a short time.

Further, for example, as shown in Japanese Utility Model Laid-Open No. 56-151728, in the adsorption surface of the mounting table surrounded by the outer edge portion of the adsorption portion, the adsorption portion and the outer edge portion are the same inorganic substance, respectively. Those formed by using those having different porosities are known.

This one can prevent the adsorption surface from being distorted due to a difference in coefficient of thermal expansion and a difference in degree of deformation due to humidity.

Furthermore, for example, as shown in Japanese Utility Model Laid-Open No. 58-180026, a plurality of fine grooves or the like are formed on the surface of a thick plate having an outer dimension slightly smaller than the outer dimension of the wafer to be processed. A suction plate is known in which a rubber-like elastic body is closely adhered to and surrounds the entire outer circumference of the thick plate while the suction hole communicating with the thick plate is made to protrude from the surface of the thick plate by a small dimension. ing.

This suction plate can prevent the polishing agent from invading the back surface of the wafer, and it can be expected that the accuracy of the wafer will be improved.

[Problems to be Solved by the Invention]

In some of the above-mentioned conventional techniques, the outer peripheral seal body for preventing the abrasive material or the abrasive material being processed from entering the workpiece is not provided on the outer peripheral portion of the suction portion.

In addition, even if the seal body is provided, there is a case in which the seal body is merely in close contact and is not subjected to polishing and grinding pressure.

Furthermore, even if the seal body is subjected to polishing and grinding pressure,
The inner peripheral portion and the outer peripheral sealing body of the adsorption portion are formed as separate bodies,
There is also a structure in which the double-sided body is joined.

Furthermore, the above-mentioned conventional technique is configured to reduce the pressure of the entire adsorption unit by the same vacuum source.

Therefore, in the structure of the suction portion, variations in polishing and grinding pressures on the workpiece occur. In addition, performing the decompression of the entire adsorption unit with the same vacuum source increases the generated variation.

For this reason, there is a problem that a difference occurs in the amount of polishing and the amount of grinding, the workpiece becomes concave, and good shape accuracy cannot be obtained.

The present invention has been made to solve the above-mentioned problems of the prior art, and in an apparatus for adsorbing and holding an object to be processed by decompression, it prevents inflow of abrasives and abrasives to the adsorbing surface, The object is to provide a vacuum suction device for polishing and grinding which can uniformly polish and grind a workpiece having high shape accuracy by negatively applying uniform polishing pressure and grinding pressure.

[Means for Solving the Problems]

In order to achieve the above object, the structure of the vacuum suction device for polishing and grinding according to the present invention is such that in a vacuum suction device for polishing and grinding which sucks and holds a workpiece by decompression, it is in contact with the workpiece and sucks it. The suction member has a suction surface of the same height and is composed of a porous body in which a soft elastic body is impregnated only in the annular outer peripheral portion, and the communication hole and the soft elastic body provided in the annular outer peripheral portion are impregnated. By depressurizing the inner peripheral portions which are not formed by separate depressurizing sources, uniform polishing and grinding pressures are applied to the work piece adsorbed on the adsorbing surfaces having the same height.

[Action]

 The functions of the above technical means are as follows.

According to the configuration of the present invention, in a vacuum suction device for polishing and grinding that sucks and holds a work piece under reduced pressure, the suction portion is an integral porous body having the same height, and a soft elastic body is provided only in the annular outer peripheral portion thereof. Since it is impregnated with, the work piece is held on the same plane and is adsorbed on each of the inner peripheral surface and the outer peripheral surface and sealed, so that double sealing is performed.

Further, since the inner peripheral portion and the outer peripheral portion are decompressed by separate decompression sources, it is possible to adjust the decompressed blood in the inner peripheral portion and the outer peripheral portion and correct a slight change in the workpiece.

If both of the above actions are added to prevent the abrasives and abrasives from entering the suction surface, a uniform polishing pressure and grinding pressure can be added.

〔Example〕

 An embodiment of the present invention will be described below.

FIG. 1 is a schematic explanatory view of a vacuum suction device according to an embodiment of the present invention.

As the adsorbing member 1, a porous body (for example, a powder sintered body such as anamina ceramics or stainless steel) is used.

The suction member 1 is supported by a holding member 3 having a groove portion 4 communicating with a vacuum source 5, one surface of which is in contact with the groove portion 4 and the other one surface forms a suction surface of a wafer 11. ing.

A groove 6 is formed on the sealing surface of the seal body 2 at the annular outer peripheral portion by impregnating the annular outer peripheral portion of the suction member 1 with a soft elastic material such as silicon rubber or polyurethane.

The groove portion 6 communicates with the vacuum source 7 and the pressurized water source 8 via a communication hole.

The vacuum source 7 and the pressurized water source 8 are provided with automatic valves 9 and 10.

Next, the operation of this embodiment will be described.

The automatic valve 9 is opened, the automatic valve 10 is closed, and the vacuum source 5 and the vacuum source 7
Are activated to bring the porous body of the adsorption member 1 and the groove 6 into a depressurized state.

The wafer 11 is vacuum-sucked by the suction surface of the porous body and the groove portion 6 of the seal body 2 in a reduced pressure state, and
Adheres to the wafer 11. Therefore, the wafer is fixed,
Is processed.

After processing, when the automatic valve 9 is closed, the automatic valve 10 is opened, the vacuum sources 5 and 7 are stopped, and the water source 8 is activated, high-pressure water spouts from the groove 6 onto the wafer 11, The wafer 11 is removed from the suction member 1.

As described above, according to the present embodiment, the wafer 11 can be easily polished and ground by using the vacuum suction device having the porous suction member 1 without sucking the abrasive and the abrasive. The sealing body 2 can be fixed, and polishing pressure and grinding pressure can be applied to the seal body 2 as well to maintain uniform polishing and grinding pressure distribution.

Next, another embodiment will be described.

FIG. 2 is a schematic view of a vacuum suction device according to another embodiment of the present invention.

The structure of the vacuum suction device including the suction member 1, the ring-shaped outer peripheral seal member 2 impregnated with the soft elastic body 2, the holding member 3, the groove portion 4, the vacuum source 5, the groove portion 6 and the like is the same as that of the invention of FIG. Since it is the same as the embodiment, detailed description thereof will be omitted, and a different structure of the suction surface will be described.

A thin hard urethane film or hard polyester film 13 is attached to the suction surface 12 of the porous suction member 1.

The film 13 has micropores 14 in the part in contact with the adsorption surface 12 of the porous body, and holes 15 in the same part as the groove 6 in the part in contact with the groove 6.

Next, the operation of this embodiment will be described.

The vacuum valve 5 and the vacuum source 7 are opened by opening the automatic valve 9 and closing the automatic valve 10.
Is activated to reduce the pressure of the porous adsorption member 1 and the groove portion 6 of the seal member 2 to reduce the pressure of the fine holes 14 and 15 of the film 13 and vacuum-adsorb the wafer 11.

As a result, the film 13 and the wafer 11 come into close contact with each other. After processing, the automatic valve 9 is closed, the automatic valve 10 is opened, the vacuums 5 and 7 are stopped, and the pressurized water source 8 is activated.
High-pressure water spouts through 15 to weaken the adhesion between the wafer 11 and the film 13 and separate them, completing the processing step.

As described above, according to the present embodiment, the wafer 11 can be polished and ground by using the vacuum suction device of the suction member 1 of the porous body without sucking the abrasives and the abrasives. Can also be applied with polishing pressure and grinding pressure to maintain uniform polishing and grinding pressure distribution.

Further, in the above two embodiments, since the suction member 1 and the seal body 2 are decompressed and sucked by the vacuum sources 5 and 7 which are separate from each other, the decompression strength depends on the shape of the wafer 11 in the supported state. Can be adjusted to correct the shape of the wafer 11.

〔effect〕

As described in detail above, according to the present invention, the work piece is adsorbed, fixedly held, the inflow of the abrasive and the abrasive is prevented on the adsorbed surface, and the work surface is uniformly polished and ground. Polishing that can grind and grind a workpiece with high shape accuracy
It is possible to provide a grinding-like vacuum suction device.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a vacuum suction device according to an embodiment of the present invention, and FIG. 2 is a schematic explanatory view of a vacuum suction device according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1 ... Porous body adsorption member, 2 ... Annular outer peripheral seal body of adsorption member impregnated with soft elastic body, 5 ... Vacuum source, 7
…… Vacuum source, 8 …… Pressurized water source, 11 …… Wafer, 13 …… Film.

Claims (1)

[Claims] 1. Polishing for adsorbing and holding a work piece under reduced pressure,
In the vacuum suction device for grinding, the suction member that comes into contact with the workpiece and adsorbs it has a suction surface of the same height and is composed of a porous body in which only the annular outer periphery is impregnated with a soft elastic body. By decompressing the communication hole provided in the annular outer peripheral portion and the inner peripheral portion that is not impregnated with the soft elastic body by separate decompression sources, respectively, the work piece adsorbed on the adsorption surface of the same height can be uniformly distributed. Vacuum adsorption device for polishing and grinding, characterized in that it is configured to apply various polishing and grinding pressures.