JPH0328371A - Production of thin film - Google Patents

Abstract

PURPOSE:To obtain a thin film having an excellent shape by heating a polymeric substrate coated with a thin film layer in the air from the thin film layer side in a non-contact state and cooling the film from the polymeric substrate side to anneal the film without curling the polymeric substrate. CONSTITUTION:A thin film of the metal or metallic compd. is formed on a polymeric substrate of polyimide or aromatic polyamide. The substrate 3 coated with the thin film is rewound from a rewinding roll 2 and wound on a winding roll 6 through a guide roller 4. The substrate 3 is heated by a non-contact heat source such as a heater 5 from the thin film side in the air or the atmosphere having the same content of oxygen, and then annealed. In this production of the thin film, a cooling gas 8 is blown against the substrate 3 through a cooling nozzle 7 from the substrate side simultaneously with the heating, and the substrate 3 is cooled. Consequently, curling of the substrate by heating is reduced, an annealing effect is caused, and a thin film having a highly smooth surface is obtained.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a conventional technology relating to a thin film manufacturing method for forming a thin film with an excellent shape.In modern society, thin film technology plays a very wide variety of roles.Thin film substrates Materials can be roughly divided into flexible substrates such as polymer films and non-flexible substrates such as glass plates based on their mechanical properties. When using a flexible substrate (above), a continuous winding method can be used as a mass production method for thin films. A thin film formed on a substrate by a method such as a vacuum deposition method or a vacuum evaporation method and then wound onto a winding roll is considered to be suitable for mass production. Although it is used in many fields including thin film formation, heat treatment called annealing is sometimes performed after thin film formation for the purpose of relieving internal stress and improving surface hardness. As shown in FIG. 2, it is possible to perform an annealing process using the temperature-raising roller 9 by running the thin film-shaped hollowed polymer substrate 3 along the temperature-raising roller 9 in the atmosphere, for example, using a winding system. In this case, wrinkles are likely to occur because the polymer substrate 3 is rapidly thermally deformed when it begins to touch the temperature-raising roller 9 and when it is separated from the temperature-raising roller 9 (1). Since it depends on the surface properties of the heating roller 9, in order to obtain a thin film with good surface smoothness, the surface of the heating roller 9 must also be smooth. Avoid these problems by using the heating roller 9. Although direct heating without using the temperature raising roller 9 is effective as one means, as shown in FIG. However, the problem to be solved by the present invention is that when the thermal contraction of the polymer substrate occurs due to the annealing treatment, the polymer substrate with the thin film formed will curl ( The higher the annealing temperature, the stronger the curl.
The purpose of the present invention is to solve the problems of the prior art, where reducing curl and providing a sufficient annealing effect are contradictory issues. Production of a thin film by forming a thin film layer on a molecular substrate directly or via a base layer, and then heating the polymer substrate in the atmosphere or in an atmosphere containing an equivalent or higher amount of oxygen by a heating method that does not contact a heat source. According to the present invention, the thin film manufacturing method is characterized in that the thin film layer side is heated and the polymer substrate side is cooled at the same time. Since cooling is performed from the substrate side, curling can be reduced compared to the case where cooling is not performed from the polymer substrate side. Figure 3 shows an example of the conventional example.
The difference from the diagram is that a cooling nozzle 7 is provided opposite the heating heater 5.As the heating heater 5, in addition to a far-infrared heater, a halogen lamp, laser, etc. can be used.Also, airflow from the cooling nozzle 7 The airflow is a clean airflow generated using a compressor.Nitrogen, oxygen, and other gases can also be used.The temperature of the airflow is set at room temperature (L) depending on the annealing temperature and other factors.Also, a cold airflow is generated using a refrigeration equipment. A film with a thickness of 250 nm was formed by vacuum evaporation on a polyimide substrate with a thickness of 10 μm and a width of 20 cm.
In order to oxidize the surface of a perpendicular magnetic recording medium with a CoCr layer, an annealing treatment was performed at a film running speed of 1 m/min.As a preliminary experiment, a thermocouple was formed by vapor deposition on the surface of the polymer substrate on the heater side. 1.
X. Calculate the heater power to keep the temperature measured by the thermocouple (annealing temperature) constant when changing the cooling air flow rate, and calculate the difference between the cooling air flow rate and the curl strength in the actual annealing process. The relationship was investigated. The curl strength was evaluated by the amount of warpage when the annealed thin film was cut into a circular shape with a diameter of 30 mm. Figure 4 shows the measurement results at annealing temperatures of 300°C and 320°C.

Figure 4: It can be seen that the curl is weakened by the cooling caused by air blowing.Also, the oxidation state investigated by electronic electron spectroscopy (Fig. A similar effect was also confirmed by annealing a 300 nm thick CoCr thin film formed on a 20 μm thick polyamide at 280°C and 300°C1.
In addition to the effects of the invention, the thin film manufacturing method of the present invention also makes it possible to reduce curls that occur during annealing.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of an annealing process in a thin film manufacturing method according to an embodiment of the present invention; FIGS. 2 and 3 are front views showing a conventional example of an annealing process;
The figure is a graph showing the relationship between the cooling air flow rate and the curl strength in the thin film manufacturing method according to the embodiment of the present invention. 3...
・Polymer group K on which a thin film is formed 4... Guide roller, 5... Heater for heating 6... Winding roller/t
,, 7... Cooling nozzle & 8... Cooling gas inlet
9...Temperature rising roller.

Claims (4)

[Claims] (1) After forming a thin film layer on a polymer substrate directly or via a base layer, the temperature of the polymer substrate is raised in the air or in an atmosphere containing an equivalent or higher amount of oxygen using a heating method that does not contact a heat source. A thin film manufacturing method comprising: heating from the thin film layer side and cooling from the polymer substrate side at the same time. (2) The method for producing a thin film according to claim 1, characterized in that an air stream is used as the cooling means. (3) The method for producing a thin film according to claim 1 or 2, characterized in that polyimide or aromatic polyamide is used as the material of the polymer substrate. (4) The method for producing a thin film according to claim 1, 2 or 3, wherein the thin film is made of a metal or a metal compound.