JP3261864B2 - Vacuum evaporation apparatus and vacuum evaporation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to vacuum deposition of a flexible plastic film having various functions which can be used in fields such as food packaging, pharmaceutical packaging, electronic equipment parts packaging, tobacco packaging, photoengraving and photosensitive photographic materials. The present invention relates to a vacuum evaporation apparatus and a vacuum evaporation method suitably used for processing.

[0002]

2. Description of the Related Art In recent years, a metal or metal oxide is coated on the surface of a flexible plastic film by a vacuum vapor deposition method to provide decorativeness, gas barrier properties, chemical resistance, wetting properties, magnetic properties, electrical conductivity, dimensional stability, etc. It has added functionality and has been used in fields such as food packaging, pharmaceutical packaging, electronic device parts packaging, tobacco packaging, photoengraving and photosensitive photographic materials. In particular, aluminum vapor-deposited films have been widely used for decoration and packaging applications. In recent years, research and development of silicon oxide vapor deposition film has been actively conducted as a transparent high barrier material with low environmental pollution, and the demand for the development of metal oxide vapor deposition technology is expected to be widespread. It is getting stronger.

[0003] In response to the expansion of these uses, mass production and reduction of processing costs have become necessary. Therefore, it is practical to shorten the processing time by increasing the processing speed by increasing the evaporation temperature, to increase the area that can be produced in one processing step by extending the width of the film to be mounted, and to increase the processing length. As a result, vapor deposition machines have become larger. In order to extend the processing length, the evaporating material crucible must be enlarged so that a large amount of evaporating material can be charged at one time, or a storage space for the evaporating material can be provided in a vacuum chamber so that it can be supplied continuously. It has been. In the case of using a sublimable evaporation material such as silicon oxide, as shown in FIG. 7, a method of continuously supplying the evaporation material heated to a sublimation temperature or higher by an electron beam heating method by slowly moving the material, An apparatus as shown in FIG.
Japanese Patent Application Laid-Open No. 2-277774), and a method of continuously supplying an evaporating raw material has been adopted.

The apparatus disclosed in Japanese Patent Application Laid-Open No. 1-252768 is very effective in improving productivity by stable quality and long-time processing, especially in the deposition of silicon oxide or the like. However, when the evaporation source has a structure in which a part of the tube is opened as shown in FIG. 5, this method also has the following disadvantages. Evaporated particles flying from a continuously supplied columnar evaporation material in the evaporation source basically fly uniformly in all directions. The vaporized particles pass through the opening of the tube while repeating collisions directly or several times, fly toward the upper film, and adhere to the film to form a vapor-deposited film. However, since the evaporation source has a structure in which a part of the tube is open, the evaporation particles also fly in the longitudinal direction of the tube. The vaporized particles flying in the longitudinal direction of the tube repeatedly adhere to the inner wall portion of the heated tube, re-evaporate and re-adhere, and finally adhere to a portion of the inner wall of the tube below the sublimation temperature of the vaporized particles. accumulate. As a result, a part of the inner wall of the tube is blocked, and a smooth continuous supply / discharge of the vaporized raw material is prevented. In other words, when the evaporated particles adhere to and accumulate on the inner wall of the tube of the evaporation source, the continuously supplied / discharged cylindrical evaporation material comes into contact with the deposited portion, thereby meandering or "clogging" the evaporation material. And the continuous supply of evaporative raw materials had to be stopped.

[0005] When the supply of the evaporation source is stopped, cracks in the evaporation source, fluctuations in the evaporation speed, and splash are generated. The fluctuations in the evaporation speed are irregular for each of a plurality of heaters of the evaporation sources. The control of the thickness and the like becomes unstable, and the generation of the splash causes the defect of the deposited film, the damage of the base film, and the mixing of foreign matter as described above. As described above, as a result, the quality of the deposited film deteriorates. Conventional vacuum evaporation equipment that continuously supplies / discharges the evaporation raw material, when the supply of the evaporation raw material is stopped, the quality of the evaporated film is remarkably deteriorated.
There is a problem that productivity is remarkably reduced.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a vacuum vapor deposition apparatus and a vacuum vapor deposition method for continuously supplying an evaporation raw material for obtaining a high productivity and a stable high quality vapor deposition film.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an evaporation material supply and discharge guide capable of continuously supplying and discharging the evaporation material, in addition to the evaporation source, at least one discharge hole for evaporating particles, and This can be achieved by a vacuum evaporation apparatus characterized in that an evaporation material supply and discharge guide between the discharge hole and the evaporation source is heated to a temperature equal to or higher than the evaporation temperature of the evaporation particles. Another object of the present invention is to provide an evaporating material supply / discharge guide capable of continuously supplying / ejecting the evaporating material, in addition to the evaporating source, at least one discharging hole for evaporating particles, and connecting the discharging hole to the evaporating source. The evaporating raw material supply / discharge guide is heated to a temperature equal to or higher than the evaporating temperature of the evaporating particles, and the evaporating particles are discharged from the discharge holes.

[0008] In the present invention, as a vacuum deposition apparatus having a mechanism for continuously supplying and discharging the evaporation raw material, Japanese Patent Application Laid-Open Nos. 1-252768 and 2-2 as shown in FIG.
No. 77774 can be used. As the evaporation material supply / discharge guide capable of continuously supplying and discharging the evaporation material, an evaporation source having a structure in which the evaporation source is integrated as shown in FIG. 1 or an evaporation source as shown in FIG. And those having a structure. The shape of the evaporation material supply / discharge guide may be either a circular tube or a square tube. The hole for discharging the evaporated particles other than the evaporation source may be circular, elliptical or square as shown in FIG. In addition, as shown in FIG. 2, when the tubular evaporation source is separate, a gap may be provided between the evaporation source and the evaporation source so that it is used as a discharge hole.

The temperature between the discharge hole of the evaporating particles and the evaporation source must be equal to or higher than the evaporating temperature of the evaporating particles so that the evaporating particles do not adhere and accumulate. The space between the evaporating particle discharge hole and the evaporation source may be heated by a conventionally known method, but may be heated to a temperature equal to or higher than the evaporation temperature of the evaporating particles by heat conduction from the evaporation source. The evaporation temperature of the evaporation particles depends on the evaporation source and the degree of vacuum. For example, when vapor deposition is performed under a pressure of 1 × 10 ⁻² Pa using SiO or a mixture of Si and SiO ₂ as a vapor deposition material, the temperature is 873 ° C. or higher. There is no particular limitation on the method of heating the evaporation material supply / discharge guide as long as it can be used in a vacuum state and can raise the temperature of the evaporation material to a predetermined temperature within a predetermined time. Conventionally known methods such as heating, direct high-frequency induction heating, indirect high-frequency induction heating, radiation heating, and electron beam heating can be used.

As a method of directly controlling the temperature between the discharge hole of the evaporating particles and the evaporation source to be higher than the evaporating temperature of the evaporating particles, there are methods such as PID control, proportional control, and fuzzy control. As a temperature measurement method therefor, a method using a conventionally known thermometer such as a thermocouple thermometer or a radiation thermometer can be used. In the case of an evaporating material supply / discharge guide having an integrated evaporating source as shown in FIG. 1, the temperature between the evaporating particle discharge hole and the evaporating source must be indirectly controlled to be equal to or higher than the evaporating particle evaporation temperature. Can be. That is, since the temperature of the evaporation source itself is temperature-controlled, by correctly grasping the difference between the temperature of the evaporation source and the temperature of the evaporation material supply / discharge guide,
In effect, the temperature control of the evaporating material supply / discharge guide between the evaporating particle discharge hole and the evaporating source is realized.

[0011] As evaporation materials, Si and SiO, Si
SiOx containing ₃ O ₄ , Si ₂ O ₃ and SiO ₂ (X = 1
And mixtures of one or two or more substances selected from silicon and silicon oxide, and mixtures and chemical bonds of silicon and / or silicon oxide with a metal compound. Examples of the metal compound include metal oxides and metal fluorides. Examples of metal oxides include magnesium oxide, calcium oxide, barium oxide, aluminum oxide, titanium oxide, zirconia oxide, sodium oxide, potassium oxide, tin oxide, indium oxide, and magnesium oxide-dioxide. Silicon oxide (forsterite, steatite), aluminum oxide-silicon dioxide cooxide (mullite), and the like can be given. Examples of the metal fluoride include fluorides of alkaline earth metals, such as magnesium fluoride, calcium fluoride, and barium fluoride, and fluorides of alkali metals, such as sodium fluoride and potassium fluoride.

[0012]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited to the following Examples unless it exceeds the gist of the present invention. In addition, the test method of the vapor deposition film obtained in the Example is as follows.
Oxygen barrier property: According to ASTM D3985, oxygen gas permeability was measured using OXTRAN-TWIN manufactured by Modern Controls of the United States. Appearance: Defects in the deposited film of the obtained deposited film and contamination with foreign matter were visually evaluated.

[Example 1] A hole having a diameter of 10 mm as shown in FIG.
４Eight in total, four at intervals. FIG. 1 shows a side view of the evaporation material supply / discharge guide. The heating method of the evaporation source was a resistance heating method, and the temperature was controlled by a radiation thermometer. Further, the temperature between the discharge hole of the evaporation raw material and the evaporation source was measured using a radiation thermometer. Next, an equimolar mixture of silicon and silicon dioxide (amorphous) was compression-molded to a diameter of 4 mm.
A cylindrical molded product having a height of 0 mm and a height of 35 mm was obtained. The obtained molded product is continuously supplied at a supply speed of 5 mm / min from a supply port of an evaporation material supply / discharge guide (made of boron nitride composite sintered body), and the evaporation source is supplied under a vacuum of 1 × 10 ⁻² Pa. Heating was performed to 1350 ° C. by resistance heating, and silicon oxide was vacuum-deposited on a 12 μm-thick polyethylene terephthalate film. The temperature between the discharge hole of the evaporation raw material and the evaporation source is 900-110.
It was 0 ° C. Under these conditions, the processing speed was 50 m / min, and vacuum deposition was performed for 1 hour. When the thickness of the deposited film was measured using a quartz crystal film thickness monitor, it was about 1000 Å.

[Comparative Example 1] The same procedure as in Example 1 was carried out except that a hole was not provided in the evaporating material supply / discharge guide of the vacuum evaporation apparatus used in Example 1. 25 minutes after the beginning of the vapor deposition, a trouble occurred due to clogging of the continuously supplied vaporized raw material. Therefore, the supply of the raw material was stopped, and the processing was continued for 5 minutes thereafter, and the vapor deposition was stopped.

The vapor-deposited films obtained in Examples and Comparative Examples were evaluated for oxygen barrier properties and appearance. Table 1 shows the results.

[Table 1]

[0016]

According to the present invention, the evaporated material can be smoothly supplied and discharged without the evaporated particles adhering and accumulating on the inner wall of the evaporated material supply / discharge guide. Therefore, high-quality deposition can be performed without any troubles such as damage to the molded product, generation of splashes due to bumping, rapid release of gas, increase in pressure in the vacuum chamber, mixing of impurities, and fluctuations in the evaporation rate. Films can be produced with high productivity.

[0017]

[Brief description of the drawings]

FIG. 1 is a side view of an evaporation source supply / discharge guide of the present invention in which an evaporation source is integrated.

FIG. 2 is a side view of an evaporation material supply / discharge guide of the present invention in which an evaporation source is separated.

FIG. 3 is a cross-sectional view of an evaporation material supply / discharge guide provided with a discharge hole for evaporating particles.

FIG. 4 is a perspective view of a vaporized material supply / discharge guide provided with a vaporized particle discharge hole.

FIG. 5 is a perspective view of an evaporation source having a structure in which a part of a tube is opened.

FIG. 6 is a side view of a conventional evaporation material supply / discharge guide.

FIG. 7 is a side view of a conventional vacuum evaporation apparatus using an electron beam heating method.

[Explanation of symbols]

1: evaporation source 2: evaporation source
3: Evaporation raw material supply mechanism 4: Evaporation particle discharge hole 5: Electron beam
6: Electrode 7: Evaporation material supply and discharge guide
8: Radiation thermometer 9: PID temperature controller 10: Electron gun

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C23C 14/00-14/58

Claims (2)

(57) [Claims] An evaporating material supply and discharge guide capable of continuously supplying and discharging the evaporating material is provided with at least one discharging hole for evaporating particles in addition to the evaporating source. A vacuum evaporation apparatus characterized in that an evaporation material supply / discharge guide is heated to a temperature equal to or higher than an evaporation temperature of evaporation particles. 2. An evaporation material supply and discharge guide capable of continuously supplying and discharging the evaporation material, wherein, in addition to the evaporation source, at least one discharge hole for evaporating particles is provided, and between the discharge hole and the evaporation source. A vacuum evaporation method comprising: heating a vaporized material supply / discharge guide to a temperature equal to or higher than the vaporization temperature of vaporized particles and discharging the vaporized particles from a discharge hole.