JPS6059105B2 - Manufacturing method of electrostatic adsorption device - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to a method for manufacturing an electrostatic adsorption device, and more specifically, an object (object to be adsorbed) is placed on a pair of electrodes with an insulator interposed therebetween, and an object is placed between the electrodes. The present invention relates to a method for simply manufacturing an electrostatic adsorption device that applies a voltage to electrostatically adsorb an object onto the electrode.

(2) Background of the technology The method of holding and fixing an object, the so-called chucking method, is usually a mechanical chuck, but if this is impossible or undesirable, a vacuum chuck, an electrostatic The method of Chuck et al.

Among these, electrostatic chuck is a method based on electrostatic attraction.
It is relatively lightweight and is advantageous for applications that require operation in a vacuum. Cases in which electrostatic chucks are particularly advantageous include semiconductor device manufacturing processes that are carried out in vacuum or under extremely low pressure. Regardless of the shape of the mechanical chuck, the chucking arms cover a portion of the surface of the wafer, and not only is it impossible to fabricate semiconductor devices on that part of the wafer, but the chucking force is only applied to a small portion of the wafer. Therefore, it is not suitable for purposes such as pressing a wafer to correct warpage and flatten it. The electrostatic chuck can be used even in a vacuum, does not require a chucking arm, and applies uniform chucking force, so it is very advantageous as a chucking method in these processes.
The first side of the electrostatic chuck is as shown in FIG.
A voltage is applied between the electrode 1 and the object 3 to attract it.

The adsorption force F obtained in this way is expressed by the following equation (1). 1
V'F■Se・E, Ding・S (1) Here, E is the dielectric constant, V is the applied voltage, d is the thickness of the insulator layer, and S is the electrode area.

(3) Prior Art and Problems In the electrostatic adsorption device of the type described above, the following two points are required for the insulator 2.

First, such an insulator should be formed as a uniform insulating film as thin as possible. According to the above formula (1), the adsorption force F
Since is inversely proportional to the square of the thickness of the insulator, it is desirable that the insulator be as thin as possible. In addition, since a strong voltage of about IKV is usually applied between the electrodes, if the thickness of the insulating film (hereinafter referred to as insulating film) is not uniform, a short circuit will occur where the film is thin, and the insulation will be insulated at that part. Membranes may be destroyed. Second, the surface of the insulating film is flat. If it is warped, a gap will be created between the insulating film and the object to be attracted. The adsorption force F is as described in (1) above.
As shown in the formula, it is proportional to the dielectric constant (E). A normal insulating film has a dielectric constant of 2 to 8, but a gap, that is, air, has a dielectric constant of 1. This means that when a gap is created between the insulating film and the object to be attracted, the attraction force is drastically reduced.
An insulating film that satisfies the above two requirements has not yet been completed.

Two measures have been proposed to solve this problem.

The method is to form an insulating film by coating it with a material with a high dielectric constant. However, if the most reliable coating method is spin coating, the thickness of the coating at the periphery will inevitably be thicker than at the center due to centrifugal force. This means that the problems of the prior art described above remain. A second countermeasure is to adhere an insulating film to the side of the electrode member opposite to the side on which the electrodes are disposed.

However, such adhesion is achieved by pressing with considerable force from the side on which the electrodes are disposed after adhering the film onto that side. As a result, unevenness corresponding to the electrode pattern appears on the opposite side, that is, on the side where the object to be attracted is placed, and this method also does not solve the problems of the prior art. (4) Purpose of the Invention In view of the above-mentioned conventional problems, the present invention provides a simple and easy way to create an electrostatic adsorption device equipped with an insulating film having a thin and uniform film thickness and an overall flat surface. To provide a method for manufacturing.

(5) Structure and object of the invention According to the present invention, in manufacturing an electrostatic adsorption device in which one or more pairs of electrodes are wrapped in an insulating film, a printed board on which a pattern of the electrodes is formed. This is accomplished by thermo-compression bonding of one or more prep legs.

(6) Examples of the Invention Examples of the present invention will be described in detail below with reference to the drawings.

FIG. 2 schematically shows an apparatus for carrying out the method of the present invention, in which 11 is an aluminum block, 12 is a lead wire connected to a power source of 1 KV, for example, and 13 14 is a prepreg made of glass fiber impregnated with uncured resin, 15 is a multilayer printed board, and 16 is formed on the printed board 15. It is an electrode. The electrode 16 corresponds to the electrode 1 in FIG. 1, and is formed by depositing a copper foil on the printed board 15 and forming a desired pattern by ordinary photo-etching technology, and its shape is flat or comb-shaped. 1 into the desired shape such as tooth shape, semicircle shape, 114 circle shape, etc.
Can be formed in pairs or multiple pairs. In the figure, 17 indicates a mold. The printed board 15 itself is made of a plurality of prepregs heated and pressed (for example, 40 to 50 kgI at 170°C).
The surface in contact with the object to be adsorbed can be formed to be extremely flat.

Furthermore, since the printed board 15 is formed by heating and pressing a plurality of sheets of prepreg having a thickness of about 0.1 wft, it can be formed to a desired thin thickness. To manufacture the electrostatic adsorption device, the process is carried out with the image shown in FIG. 2 inverted.

The printed board 15 is placed on the mold 17 with the electrode 16 facing upward and the lead 121 and the embedded body 13 attached thereto. Next, one or more prepregs 14 are placed on the electrode 16. As mentioned above, the thickness of the prepreg is 0.
It costs about 1Tf$L. Next, prepreg 14
A block 11 made of aluminum, for example, having an uneven surface is placed on the surface facing. This block 11 is heated to about 170° C. by a means not shown, and then pressurized with a force of about 40 to 50 k91 d. At this time, the prepreg melts due to heating, enters the recess in the pattern of the electrode 16 due to pressure, and when the heating of the block 11 is stopped, it hardens in 1 to 2 hours and forms a printed board with electrodes. It is integrated with prepreg.

Then, the block 11 is separated from the prepreg 14.

Since the surface of the block 11 in contact with the prepreg 14 has irregularities as described above, the prepreg 14 is easily separated from the block 11. The completed electrostatic chuck device is used in the state shown in FIG. 2, and an object to be chucked is placed at the position of the mold 17.

(7) Effects of the invention As explained in detail above, the unevenness of the electrode pattern is absorbed by the prepreg as it melts during thermocompression bonding, and the surface flatness is extremely good, and the thickness of the printed board and prepreg is Since uniform products are easily available, the problems of the prior art are solved in the electrostatic adsorption device formed by the method of the present invention. A product with a membrane is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a conventional electrostatic chuck device, and FIG. 2 is a schematic cross-sectional view of an apparatus for carrying out the method of the present invention.

11...Block, 12...Lead wire, 13...Adhesive embedded body, 14...
Prepreg, 15...Printed board, 16...
...electrode, 17...mold.

Claims (1)

[Claims] 1. A method for manufacturing an electrostatic adsorption device having a structure in which one or more electrodes are wrapped in an insulating film, which comprises: a printed board on which a pattern of the electrodes is formed; one or more prepregs; A method of manufacturing an electrostatic adsorption device, characterized in that the two are integrated by thermocompression bonding.