JPS63114872A - Surface polishing device - Google Patents

Abstract

PURPOSE:To sustain the flatness with a high degree of accuracy, by filling polishing liquid in a liquid tank to such a degree that a stool and a pressurizing plate are sunk into polishing liquid during the workpiece is polished, so as to prevent the temperatures of a stool and a pressurizing plate from rising and to prevent occurrence of the difference in pressure between the upper and lower surfaces. CONSTITUTION:A drive source 12 rotates a liquid tank 11 together with a stool 13 in the liquid tank 11. In this condition, a pressurizing plate 22 is lowered so that a workpiece 23 bonded to the lower surface of the pressurizing plate 22 is made into press-contact with the upper surface of the stool 13 on rotation under a predetermined pressure in order to polish the workpiece 23 by the stool 13. Meanwhlie, polishing liquid 14 is circulated from the liquid tank 11 by means of a pump 18 through a suction pipe 16, a temperature managing device 15 and a supply pipe 17 to cool the stool 13 and the workpiece by the polishing liquid 14 so as to prevent a temperature rise of the stool 13 and the transmission of heat to the pressurizing plate 22. As a result the polishing liquid whose temperature is raised, is cooled while it circulates through the temperature managing device 15, thereby it is possible to maintain the liquid at a set temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application 1] The present invention relates to a surface polishing apparatus that performs TIF polishing by bringing a workpiece into pressure contact with a rotating surface plate.

[Prior Art] Generally, when polishing a workpiece by pressing it against a rotating surface plate using a pressure plate, heat is generated at the interface between the workpiece and the surface plate.
Because the surface plate and pressure plate are thermally deformed and their flatness deteriorates, it is not possible to grind the workpiece with the desired accuracy.

Therefore, in order to solve this problem, for example, in Japanese Utility Model Publication No. 80-21174, a cooling chamber is provided inside the surface plate, and cooling water is supplied into the cooling chamber in a circular manner. A device designed to prevent the temperature rise of the surface plate has been proposed, and has achieved remarkable results in that it can prevent ground deformation due to the extreme temperature rise of the surface plate and improve polishing precision.

However, although the above-mentioned conventional device can prevent severe thermal deformation of the surface plate, it cannot completely prevent even the relatively minute thermal deformation due to the temperature difference between the upper and lower surfaces. It has been difficult to apply it to precision polishing, which requires In other words, when cooling water is passed through the surface plate in this way, the top surface of the surface plate heats up due to processing, but the bottom surface does not rise in temperature due to cooling, so a large temperature difference occurs between the top and bottom surfaces, and the temperature Due to the difference, the surface plate becomes distorted and flatness cannot be maintained. Moreover, since the temperature difference changes with the temperature change on the top surface of the surface plate depending on the processing time, etc., the flatness of the surface plate also changes, making it impossible to polish the workpiece under constant conditions. Similar considerations were made regarding the pressure plate.

Especially in recent years, extremely high polishing precision has been required for polishing single conductor wafers, vacuum equipment, etc.
In order to meet this demand, it is extremely important to strictly control the temperature of the surface plate and pressure plate as described above, as well as the temperature difference between the upper and lower surfaces, and to properly control their flatness.

[Problems to be Solved by the Invention] The problem of the great invention is to eliminate temperature changes in the constant i and pressure plates and temperature differences between the upper and lower surfaces, and to provide surface polishing that makes it possible to control their flatness with high precision. The goal is to provide equipment.

Means for Solving the Problems] In order to solve the above problems, the great invention includes a rotatable surface plate and a pressure plate that presses the workpiece against the surface plate, and the pressure plate presses the workpiece. In a device in which polishing is performed while pressing against a surface plate with a constant pressure, the surface plate is provided in a liquid tank.1. The present invention is characterized in that the liquid bath is filled with polishing liquid to such an extent that the surface plate and pressure plate are immersed during polishing of a workpiece, and that a temperature control device for the polishing liquid is attached.

[Function] A workpiece is pressed against the upper surface of a rotating surface plate under constant pressure by a pressure plate while immersed in a polishing liquid, and the workpiece is polished by the surface plate.

On the other hand, the polishing liquid is always maintained at a constant temperature by a temperature control device.

Here, when the surface plate and workpiece generate heat due to the polishing process, the heat is immediately cooled by the polishing liquid, preventing the temperature of the surface plate from rising and heat transfer to the pressure plate. The surface plate and pressure plate are not only kept at a constant temperature at all times, but also have no temperature difference between the upper and lower surfaces, and no distortion such as warpage or deformation due to temperature changes or temperature differences.

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, 10 is the body of a flat surface polishing apparatus,
A liquid tank 11 is rotatably attached to the body 10, and the liquid tank 11 is connected to a drive source 12 such as a motor via a drive shaft 11a provided on the lower surface of the liquid tank 11.

Inside the liquid tank 11, an annular ring 913 with a center hole 13a extends slightly from the bottom surface 11b of the liquid tank 11.
The polishing liquid 1 filled in the liquid tank 11 while being polished
A temperature control device 15 for controlling the temperature of the polishing liquid is attached to the liquid tank 11 via a pump 18. A fin 19 for stirring the polishing liquid 14 is provided. The fins 18 are fixedly disposed so as not to rotate together with the liquid (11), and stir the polishing liquid by the rotation of the liquid tank 11.

Further, the temperature control device 15 described in 1 and 1 is equipped with liquid temperature control means such as a temperature sensor and a heat exchanger for detecting the liquid temperature, and carries the polishing liquid 14 in the liquid tank 11 to the suction pipe 16 and the supply pipe 17. The suction pipe 16 is connected to the liquid tank 11 while circulating the liquid by a pump 18 to maintain the temperature of the liquid at a set temperature.
A supply pipe 17 is disposed at the center of the liquid tank 14 on the outer periphery of the liquid tank 14 . In this case, the polishing liquid 14 is also exposed to the suction pipe 16 immersed in the polishing liquid 14.

A plurality of air cylinders 20 are installed on the body 10 on the side of the liquid tank 11, and a pressurizing head 21 is attached to each of these air cylinders 200 rods. A pressure plate 22 for holding a workpiece 23 attached to the plate 21 is detachably attached, and the workpiece 23 attached to the lower surface of the pressure plate 22 is pressed against the surface plate 13 by the cylinder 20 and polished. It has become so.

Note that the cylinder 20 is connected to compressed air ff125 via an air pressure 1 regulating valve 24. Also 28 in 1 figure
is the drain outlet.

Next, the operation of the surface polishing apparatus having the above configuration will be explained.

When the liquid tank 11 is rotated by the drive 'a12 with the pressure plate 22 raised by the cylinder 20,
The constant a13 installed in the liquid 1611 also rotates together with the liquid tank 11. In this state, the pressure plate 22 is lowered,
Surface plate 130 on which the workpiece 23 attached to the lower surface rotates
One surface is pressed with a constant pressure by a cylinder 20, and polished by the surface plate 13.

On the other hand, the polishing liquid 14 in the liquid tank 11 is pumped through the suction pipe 16 by the pump 18. It is circulated through a temperature control device 15 and a supply pipe 17.

Here, if the temperature of the polishing liquid 14 is lower than the set temperature at the start of processing, etc., the polishing liquid 14 is heated by the temperature control device 15 and maintained at the set temperature.

Furthermore, when the surface plate 13 and the workpiece 23 generate heat due to the polishing process, the heat is immediately cooled by the polishing liquid 14.
A rise in temperature of the surface plate 13 and heat transfer to the pressure plate 22 are prevented. Therefore, these surface plate 13 and pressure plate 22 are not only kept at a constant temperature at all times, but also do not have a temperature difference between the upper and lower surfaces, and are not subject to distortion such as warping or deformation due to temperature changes or temperature differences. do not have.

On the other hand, when the temperature of the polishing liquid 14 rises by cooling the surface plate 13 and the pressure plate 22, it passes through the temperature control device MI5 and is cooled to a constant temperature, thereby maintaining the set temperature. Therefore, a decrease in cooling efficiency due to an increase in the temperature of the polishing liquid 14 and generation of distortion due to an increase in the temperature of the surface plate 13 and pressure plate 22 do not occur.

[Effect of the invention] Thus, according to the surface polishing apparatus of the present invention.

Since the workpiece is polished while the surface plate and pressure plate are immersed in the polishing liquid, the temperature rise of the surface plate and pressure plate and the temperature difference between the upper and lower surfaces can be prevented. It is possible to prevent thermal deformation and to control its flatness with high precision.

Furthermore, since the polishing liquid is always kept at a constant temperature using a temperature control device, it is possible to prevent temperature changes that occur during processing of the fixing plate and pressurizing plate, thereby further increasing processing accuracy. It becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of an embodiment of the present invention. 13. Surface plate, 14. Polishing liquid, 15Φ.
Temperature control device, 22. Pressure plate, 23. Work.

Claims (1)

[Claims] 1. A rotatable surface plate and a pressure plate that presses the workpiece against the surface plate, and the pressure plate presses the workpiece against the surface plate with a constant pressure while polishing. A disk is provided in a liquid tank, and the liquid tank is filled with polishing liquid to such an extent that the surface plate and pressure plate are immersed during polishing of a workpiece, and a temperature control device for the polishing liquid is attached. Surface polishing equipment.