JPS58171233A - Manufacture of electrostatic attracting device - Google Patents

Abstract

PURPOSE:To enable favourable flatness of the surface and even attraction, by unifying a printed board and a prepreg through thermal press welding, at the time of electrostatic attraction by applying voltage between electrodes by providing a material to be attracted on a pair of electrodes through an insulator. CONSTITUTION:To manufacture an electrostatic attracting device, a process is advanced in an inverted state of a sketch. A printed board 15 is provided on a metallic die 17 under a state wherein electrodes 16 are turned upward, and a lead 12 and a burying body 13 are equipped. A prepreg 14 is placed on the electrodes 16. Then, a block having unevenness on its surface facing toward the prepreg 14, for example, the block 11 made of aluminum is placed. The block 11 is heated and pressured. The prepreg is fused by heating, entered into a concave part in a pattern of the electrodes 16 through pressing and the printed board and the prepreg are unified.

Description

Detailed Description of the Invention +11 Technical Field of the Invention The present invention relates to a method for manufacturing an electrostatic adsorption device, in particular, 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, and when this is impossible (1) or undesirable, Methods such as vacuum chuck and electrostatic chuck are used. Among these, the electrostatic chuck is a method based on electrostatic attraction, and is advantageous for applications that are relatively lightweight and 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 part of the surface of the wafer, and not only cannot semiconductor devices be fabricated on that part of the wafer, but also
Since the chucking force is only applied to a small portion of the wafer, it is not suitable for purposes such as pressing the wafer to correct warpage and flatten it. Electrostatic chucks can be used even in a vacuum and do not require a chucking arm.
Since the chucking force is applied uniformly, this is a very advantageous chucking method in these processes.

An example of an electrostatic chuck is as shown in FIG.
A voltage (2) 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 formula +11.

Here, ε represents the dielectric constant, ■ represents the applied voltage, d represents the thickness of the insulator layer, and S represents 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 equation (11), the adsorption force F is inversely proportional to the square of the thickness of the insulator, so it is desirable that the insulator be as thin as possible.Also, a strong voltage of about IKν is normally applied between the electrodes. Therefore, if the thickness of the insulating film (hereinafter referred to as an insulating film) is not uniform, a short circuit may occur at a thinner part and the insulating film may be destroyed at that part.

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 proportional to the dielectric constant (ε) as seen in the equation +11 above. A normal insulating film (3) 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. That means,
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 can be done by pressing with considerable force from the side on which the electrodes are arranged after the film has been applied on that side.

(4) 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.
This method also does not solve the problems of the prior art described above.

(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 chuck device having an insulating film that is thin, uniform, and has 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 achieved by thermocompression bonding of one or more sheets of prepreg.

(6) Examples of the invention Embodiments 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, for example, an aluminum block, 12.12 is a lead wire connected to, for example, an IKV power source (5). , 13 is an adhesive embedded body for holding and insulating the lead wire 12, 14 is a prepreg made of, for example, glass fiber impregnated with uncured resin, 15 is a multilayer printed board, and 16 is formed on the printed board 15. This 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 using a normal photoetching technique, and its shape is a flat plate or a comb. They can be formed in one pair or in many pairs in a desired shape, such as a shape, a semicircle, or a quarter circle. In the figure, 17 indicates a mold.

The printed board 15 itself is formed by heating and pressing multiple sheets of prepreg (for example, at 170°C and pressing with a force of 40 to 50 kg/cm2), and the surface in contact with the object to be attracted can be formed to be extremely flat. It is.

Furthermore, since the printed board 15 is formed by heating and pressing a plurality of sheets of prepreg with a thickness of about 0.1 mm,
It is possible to form it with 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 (6) is placed on the mold 17 with the electrode 16 facing upward and the lead 12 and the embedded body 13 attached. Next, one or more prepregs 14 are placed on the electrode 16. The thickness of the prepreg is approximately <0.1 mm as described above. Next, a block 11 made of aluminum, for example, whose surface facing the prepreg 14 has unevenness is placed.

This block 11 is heated to about 170° C. by means not shown, and pressurized with a force of about 40 to 50 kg/cm 2 .

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 the printed board with the electrode and the prepreg are integrated. become

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 adsorption device is used in the state shown in Figure 2.
An object to be attracted is placed at the position of the mold 17.

(7) (7) Effects of the invention As explained in detail above, the unevenness of the electrode pattern is absorbed by the prepreg which melts during thermocompression bonding, and the surface flatness is extremely good, and the printed board and prepreg are thick. Since devices with uniform thickness are easily available, the problems of the prior art are solved in the electrostatic adsorption device formed by the method of the present invention, which is thin, has a uniform thickness, and has a flat surface. A product with an insulating film can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a conventional electrostatic chuck device, and FIG. 2 is a schematic cross-sectional view of a device implementing the method of the present invention. 11- Block, 12- Lead wire, 13- Adhesive embedded body, 14- Prepreg, 15- Printed board,
16-electrode, 17-・mold (8)

Claims (1)

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