JP2002339073A - Applied electrode temperature adjusting device of plasma cvd apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an applied electrode temperature adjusting device capable of reducing accidents caused by an electric leak and eliminating power losses in a plasma CVD apparatus. SOLUTION: In the applied electrode temperature adjusting device of the plasma CVD apparatus, a temperature-adjusting liquid-contact part of the electrode is covered by an electric insulating material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling the temperature of an applied electrode of a plasma CVD apparatus.

[0002]

2. Description of the Related Art In a plasma CVD apparatus, a pipe is formed in contact with an applied electrode for the purpose of cooling or heating the applied electrode.
A temperature adjusting mechanism for flowing a refrigerant or a heat medium is employed.

[0003] Although a metal pipe or the like is used as a pipe through which the refrigerant or the like flows, there is a problem that electric leakage easily occurs from a path based on a temperature control liquid such as a refrigerant.
In particular, in the plasma CVD process under the atmospheric pressure, which has been attracting attention in recent years, the applied voltage is as high as ten and several kV or more, so that the influence cannot be ignored. One method for solving this problem is to use a perfluorocarbon, hydrofluoroether, or a mixture of pure water and ethylene glycol as a temperature control liquid having a large electric insulation to prevent electric leakage. 2000-2006
No. 97 is disclosed. However, even if a temperature control liquid with a large electrical insulation is used, if the elution of ions from the metal part progresses, the non-conductivity is lost and electric leakage occurs, causing a risk of power loss or electric shock accident. Although it depends on the time, it is necessary to replace the temperature control liquid about once every 200 hours on average, and the current leakage problem has not been completely solved yet.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an apparatus for controlling the temperature of an applied electrode in a plasma CVD apparatus, which can reduce accidents due to earth leakage and eliminate power loss. And

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, by covering the liquid-contacting part with an electrically insulating material in the piping of the temperature control device of the applied electrode. The present inventors have found that ions can be prevented from being eluted into the temperature control solution, the temperature control solution can be kept non-conductive for a long period of time, and leakage and power loss can be suppressed, thus completing the present invention.

That is, a first aspect of the present invention is an application electrode temperature control apparatus for a plasma CVD apparatus, wherein the temperature control liquid contact portion of the electrode is coated with an electrically insulating material. It is an electrode temperature control device.

According to a second aspect of the present invention, the electric insulating material is an insulating material having an internal resistance of not less than 10 ⁹ ρ / Ω · m. It is a temperature control device.

According to a third aspect of the present invention, there is provided an application electrode according to the first or second aspect, wherein ion-exchanged water is used as a temperature control liquid, and all liquid contact portions are made of resin. Temperature control device.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus of the present invention is a plasma CVD apparatus.
In a device having a structure in which an applied electrode of the device is cooled by a refrigerant, the electrode is cooled through a refrigerant inside the electrode, and the refrigerant whose cooling capacity is lowered by lowering the temperature of the electrode is cooled by a heat exchanger provided outside. This is a device in which a part in contact with a temperature control liquid, which is a refrigerant, in a temperature control device that circulates with improved capacity is coated with an electrically insulating material.

An example of a temperature control device for an applied electrode according to the present invention will be described with reference to the drawings. However, the present invention is not limited thereto without departing from the spirit of the present invention. FIG.
FIG. 3 is a view schematically showing a system in which a cooling capacity is reduced from an applied electrode, the cooling capacity is restored through a heat exchanger, and the temperature regulating liquid is circulated to the electrode. The temperature control liquid whose temperature has risen by cooling the hot electrode in the electrode 1 to be cooled to a predetermined temperature is circulated through the flow pipe 3 in the direction of the arrow, and the flow rate is controlled by the flow meter 8 to exchange heat. It is introduced into the vessel 2. In the heat exchanger 2, the temperature control liquid flows through the spiral tube 4, exchanges heat with the secondary cooling water introduced from the cooling water inlet 21 of the heat exchanger 2 and discharged from the outlet 22, and a predetermined temperature. Cooled to temperature. The cooled temperature control liquid is returned to the electrode 1 through the flow pipe 5, and
Cooling control of the temperature. Further, the temperature of the temperature control liquid can be finely adjusted while opening and closing the valve with the temperature indicator (TI) 9. Further, the replenishment of the temperature control liquid is appropriately replenished from the reserve tank 7 through the distribution pipe 6, and the waste temperature control liquid is supplied to the drain valve 10.
It can be discharged more appropriately.

Although not shown in the drawings, a pump for circulating the temperature control liquid, an infrared radiation thermometer for controlling the surface temperature of the electrode, and a temperature controller for interlocking the temperature sensor such as a thermocouple with the temperature of the temperature control liquid. It is necessary to provide a control means composed of the following. Further, it is preferable to provide a mechanism for measuring the electric resistance of the temperature control liquid for monitoring the conductivity state of the temperature control liquid.

The present invention is an apparatus in which a liquid contact portion, such as a pipe, in contact with a temperature control liquid as a refrigerant as described in the above-mentioned figure is covered with an electrically insulating material. Examples of the liquid contact portion of the temperature control liquid include a flow pipe, a pipe joint, a spiral tube in heat exchange, and an inner wall of a reserve tank for the temperature control liquid. When a cooling mechanism with a small hole is used for the inside of the electrode, it is technically difficult to cover the inner surface of the hole, which may lead to an increase in cost.

The electrically insulating material that can be used in the present invention is not particularly limited as long as it has electrical insulation properties and can coat the inside of a pipe or form it into a pipe or the like. Rubber, ceramics, plastics and the like are preferred. Further, the internal resistance of the electrically insulating material is 10
A material with ⁹ ρ / Ω · m or more is preferable, and
0 ¹⁵ ρ / Ω · m or more. Among these, plastics having an internal resistance of 10 ⁹ ρ / Ω · m or more are particularly preferable from the viewpoint of moldability and the like. Internal resistance is 10 ⁹ ρ / Ω.
If it is less than m, there is a possibility that current will flow depending on the current / voltage conditions and the thickness of the electrically insulating material.

Examples of the plastic include acrylic resins, epoxy resins, polyvinyl chloride resins, polytetrafluoroethylene resins, polyamide resins, polyurethane resins, polyethylene resins, and polystyrene resins. Pipes, pipe joints, etc. are excellent in workability,
A non-polar and highly chemical-resistant polyolefin-based resin such as polyethylene resin is preferred. Further, since it is difficult to coat the inside of the spiral tube or the like in the heat exchanger, a polyurethane resin or a polytetrafluoroethylene resin can be directly formed into a spiral tube, which is preferable because it has elasticity and excellent workability.

The temperature control liquid is preferably a liquid having electrical insulation, non-combustibility and chemical stability. Ethylene glycol is added to perfluorocarbon, hydrofluoroether or pure water having high electrical insulation.
A mixed solution, pure water, and ion-exchanged water to which 〜60% by weight is added. Among these, it is preferable to use pure water and ion-exchanged water from the viewpoint of cost and handleability. Such a temperature control liquid having an insulating property is suitable for preventing electric leakage from an electrode to which a high voltage is applied.

[0016] The heat exchanger may be, for example, a double-pipe type heat exchanger, provided that the pipe and the connecting portion thereof in contact with the temperature control liquid are coated with an electrically insulating material or are formed of an electrically insulating material. The heat exchanger may have any shape such as an exchanger, a coil heat exchanger, a cascade heat exchanger, and a flat plate heat exchanger.
The heat exchanger described with reference to FIG. 1 is one of coil heat exchangers, and it is preferable that the coiled pipe be a urethane tube with a stainless steel casing.

The temperature control device for the application electrode as described above is
It is preferably installed in a plasma CVD apparatus, particularly, a plasma CVD apparatus performed at atmospheric pressure. Further, the temperature control device of the present invention can also be installed in a plasma generator or the like.

[0018]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 An electrode temperature controller as shown in FIG. 1 was added to a plasma CVD apparatus using an aluminum electrode having a cooling hole in the electrode to control the temperature of the electrode during the CVD process. . In the CVD process, a voltage of 15 kV is applied to the electrode, and the polyimide film is processed in a mixed gas obtained by diluting 0.1% of silane and 1% of hydrogen with argon gas. The temperature of the electrode is adjusted. If not, 300 ℃
In order to increase the temperature, the temperature was kept constant at about 80 ° C. In the apparatus shown in FIG. 1, the inside of the pipe was coated with urethane resin, the spiral pipe in the heat exchanger was made of polyurethane, and all the liquid contact parts were made electrically insulating so that the pipe pressure loss was 100 kPa at the maximum. In addition, ion exchange water is used as the temperature control liquid (refrigerant), and the heat exchange amount
0 W / h, flow rate 20 l / min, 20 as secondary cooling water
° C water was used. As a result, there is no leakage of the temperature control liquid,
Processing could be performed stably.

[0020]

According to the temperature control device for the applied electrode of the plasma CVD apparatus of the present invention, the portion in contact with the temperature control solution is covered with an electrically insulating material, so that an electric shock accident during plasma processing and a leakage prevention can be prevented. Process stability and power loss,
This is an effective device for cost reduction.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode 2 Heat exchanger 3 Temperature control liquid pipe 4 Spiral tube 5 Temperature control liquid pipe 6 Temperature control liquid replenishment pipe 7 Temperature control liquid reserve tank 9 TI 10 Temperature control liquid drain valve 21 Secondary cooling water inlet 22 Secondary cooling Water outlet

Claims (3)

[Claims] 1. An apparatus for controlling the temperature of an applied electrode of a plasma CVD apparatus, wherein a liquid contact portion of the electrode for controlling the temperature of the electrode is coated with an electrically insulating material. 2. An electric insulating material having an internal resistance of 10 ⁹ ρ /
2. An insulating material having a resistance of not less than Ω · m.
3. The temperature control device for an application electrode according to claim 1. 3. Use of ion-exchanged water as a temperature control liquid,
The apparatus for controlling the temperature of an application electrode according to claim 1, wherein the liquid contact portion is entirely made of resin.