JPH0754641B2 - Reflecting mirror and manufacturing method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a reflecting mirror used for a certifying device or the like, and more particularly to a reflecting mirror formed by forming a dielectric film layer on a metal substrate.

[Prior Art] Conventionally, for example, in a cold mirror (metal dichroic mirror) whose substrate is made of metal, a color lamp mirror, and the like, an absorption layer made of a dielectric material is arranged on the surface of the substrate, and a specific wavelength range is formed on the absorption layer. A dielectric film layer formed of a dielectric multilayer film having a characteristic of reflecting only the light of (4) and transmitting the light of another wavelength range is provided. That is, in the cold mirror, infrared rays, which are heat rays, pass through the dielectric film layer (cold mirror layer) without being reflected, reach the infrared absorption layer, and are radiated from the back surface of the metal substrate. In addition, only the light of a specific wavelength (color) is reflected by the color lamp mirror.

These reflecting mirrors have different physical properties such as expansion coefficient between the dielectric film layer and the metal substrate, and also have poor adhesiveness to each other. Therefore, 1) anodize the substrate by anodizing or the like,
After that, the absorption layer and the dielectric multilayer film are formed by the vacuum vapor deposition method, or 2) a coating film is formed on the metal substrate by spraying, brush coating, etc. to perform the base treatment, and then the absorption layer is sprayed or the vacuum vapor deposition method. After the formation, the dielectric multilayer film was formed by a vacuum vapor deposition method.

[Problems to be Solved by the Invention] However, the conventional methods require at least two completely different properties such as alumite treatment, spraying, brush coating, and vacuum deposition. As a result, it is difficult for the equipment, and the air is exposed to air between the processes, and the adhesion of the dielectric film layer formed on the undercoating is reduced due to the pollutants in the air.

In addition, the surface state before applying the dielectric film layer by alumite treatment, spraying, brushing, etc. is already lacking smoothness, and the dielectric film layer is applied on top of it, so the reflectance and optical characteristics of the finished product deteriorate. There was a flaw.

An object of the present invention is to provide a reflecting mirror having excellent adhesion between a substrate and a dielectric film layer and having a smooth surface state, and a manufacturing method thereof.

[Means for Solving the Problems] In order to achieve this object, the present invention bridges between two materials having different physical properties of a metal substrate and a dielectric film phase and having poor adhesion to each other. Therefore, an intermediate film layer having properties close to the substrate on the substrate side and properties close to the dielectric film layer on the dielectric film layer side is provided.

That is, the first invention is a reflecting mirror in which a dielectric film layer is formed on the surface of a metal substrate formed into a desired shape, and in the vicinity of the substrate, between the substrate and the dielectric film layer. A second aspect of the present invention is a reflecting mirror comprising a metal and a lower oxide thereof and having an intermediate film layer of a higher oxide thereof as the dielectric film layer is approached. By the ion plating method, the amount of O ₂ gas introduced into the vacuum chamber is gradually increased, and the metal is formed on the surface of the metal substrate, near the substrate is made of metal and its lower oxide, and as the film thickness increases, it is made of higher oxide. Thus, the method for manufacturing a reflecting mirror is characterized in that the intermediate film layer is formed as described above, and then the dielectric film layer is continuously formed thereon.

Examples of the metal forming the substrate include aluminum (Al), copper (Cu), nickel (Ni), titanium (Ti), alloys of these, and stainless steel.

Further, as the metal of the intermediate film layer and the metal constituting the oxide thereof, the same metal as that of the substrate, or another metal if the adhesion with the substrate, the film strength, the coefficient of thermal expansion, etc. are applicable,
For example, chromium (Cr), zirconium (Zr), indium (In), etc. can be used.

As the dielectric film layer, zinc sulfide (ZnS), magnesium fluoride (MgF ₂ ), chromium oxide (Cr ₂ O ₃ ), titanium oxide (T
iO ₂ ), silicon oxide (SiO ₂ ), tantalum oxide (Ta ₂ O ₅ ).
The dielectric film such as is made into a multi-layered structure depending on the use of a cold mirror, a color mirror or the like.

[Operation] In the first invention, the intermediate film layer formed between the metal substrate and the dielectric film layer is made of metal and its lower oxide (having a dielectric property) in the vicinity of the substrate. It has characteristics close to those of metal, and has characteristics close to those of a dielectric film layer made of a higher oxide (having a dielectric property) whose oxidation progresses as the film thickness increases and approaches the dielectric film layer. It bridges the dielectric film layers of metals with different characteristics to improve the adhesion.

In the second invention, in order to form the interlayer film of the first invention,
By gradually increasing the amount of O ₂ gas introduced into the vacuum container by the ion plating method in the vacuum container, an intermediate layer film is formed on the surface of the metal substrate, and oxidation progresses to lower oxides. Then, an intermediate film layer is formed so that the amount of higher oxides gradually increases, and thereafter, a dielectric film layer is continuously formed on the intermediate film layer without being exposed to the atmosphere.

[Embodiment] In FIG. 1, the cold mirror is aluminum (Al).
It has a bowl-shaped part 2 and a lamp mounting part 3. On the inner surface of the bowl-shaped portion 2, as shown in FIG. 2, an intermediate film layer 4, an infrared absorption layer 5 made of a dielectric material of Cr ₂ O ₃ , and a TiO 2 layer.
_A cold mirror layer 6 made of a dielectric alternating multilayer film of ₂ and SiO ₂ is formed.

The intermediate film layer 4 is mostly Al and a little AlO in the vicinity of the substrate 1, but the amount of AlO and Al ₂ O ₃ increases as it approaches the infrared absorption layer 5, and almost stable Al _{2 in the} vicinity of the infrared absorption layer 5. O ₃
It has a tendency to tilt. (Third
Figure).

FIG. 4 shows a high-frequency ion plating device for manufacturing such a reflecting mirror.
A substrate holder 12, an RF coil 13, an Al and infrared absorption layer, an evaporation source 14 having a crucible containing a sample (deposited material) for forming a dielectric alternating multilayer film, a film thickness meter 15 are arranged,
An oil rotary pump 16, an oil diffusion pump 17, and a gas supply device 18 are connected to the vacuum container 11. The evaporation control of the sample forming the Al and infrared absorption layers and the alternating dielectric multilayer film is performed by moving the shutter 19 provided above the evaporation source.

The Al substrate 1 formed into a desired shape is set on the substrate holder 12 in the vacuum container 11, the air in the vacuum container is exhausted by the oil rotary pump 16 and the oil diffusion pump 17, and then the substrate is subjected to bombard cleaning with high frequency. After removing dirt and oxides on the surface, argon (Ar) gas was introduced from the gas supply device 18, Al vapor deposition was started in the plasma, and the amount of Ar gas introduced was gradually reduced to oxygen (O ₂ ). By increasing the amount of gas introduced, the oxidation of Al is promoted, and as the film thickness increases, the dielectric substances AlO and Al ₂ O ₃ increase, and finally Al ₂ O
_It consists of _three . The thickness of the intermediate film layer 4 thus formed is about 0.1 to 2 μm.

The shutter 19 is opened and closed to further continuously deposit another heated deposit of the evaporation source, and the infrared absorbing film layer 5 which is the same dielectric film on the surface of the intermediate film layer 4 and the cold mirror thereon. Form layer 6.

In this embodiment, the intermediate film layer made of Al and its oxide is formed on the Al substrate, but Cu, Ni, Ti, alloys of these, stainless steel or the like may be used for the substrate. As the metal and its oxide of the intermediate film layer, the same metal and its oxide as the substrate (eg CuO, NiO, TiO ₂ ) or the adhesion to the substrate, the film strength, the coefficient of thermal expansion, etc. are applicable. If Cr,
Zr, In and oxides thereof (Cr ₂ O ₃ , ZrO ₂ , In ₂ O ₃ ) and the like may be used.

[Advantages of the Invention] In the first invention, in a reflecting mirror in which a dielectric film layer is formed on the surface of a metal substrate formed into a desired shape, between the substrate and the dielectric film layer, There is an intermediate film layer consisting of a metal and its lower oxide near the substrate, and a higher oxide thereof as it approaches the dielectric film layer. This intermediate film layer has characteristics close to the metal of the substrate near the substrate. However, as the film thickness increases and approaches the dielectric film layer, the film has properties close to those of the dielectric film layer, so the adhesion between the metal substrate and the dielectric film layer is extremely good, and the durability is high. Moreover, since it can be formed by the ion plating method, it has the advantages that the surface of the intermediate film layer is smooth and the reflectance and optical characteristics are excellent.

In the second invention, the amount of O ₂ gas introduced into the vacuum container is gradually increased by the ion plating method in the vacuum container, and the metal and the lower oxide thereof are separated from the surface of the metal substrate near the substrate. Is an invention of a method in which an intermediate film layer made of a higher oxide is formed as the film thickness increases, and then a dielectric film layer is continuously formed thereon. An intermediate film layer having similar properties and a property close to that of the dielectric film layer on the side of the dielectric film layer, and having a smooth surface is obtained, and the dielectric film layer is continuously formed. It is possible to obtain a reflecting mirror having excellent adhesion between the film layer and the dielectric film layer and having durability and excellent reflectance and optical characteristics. In addition, there is an advantage in that the equipment can be manufactured by one device.

[Brief description of drawings]

FIG. 1 is a partially cutaway view showing an embodiment of a reflecting mirror of the present invention, FIG. 2 is a view showing a film layer structure, and FIG. 3 is a inclination tendency of a metal and an oxide thereof constituting an intermediate film layer. FIG. 4 is a diagram showing Al as an example, and FIG. 4 is a diagram showing an example of a manufacturing apparatus for manufacturing the reflecting mirror of the present invention. 1 ... Substrate, 4 ... Intermediate film layer, 5 ... Dielectric film layer (infrared absorbing film layer), 6 ... Dielectric film layer (cold mirror layer)

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C23C 14/08 Z 9271-4K G02B 5/08 C 9224-2K

Claims (2)

[Claims] 1. A reflecting mirror comprising a dielectric film layer formed on the surface of a metal substrate formed into a desired shape, wherein a metal and a metal film are formed between the substrate and the dielectric film layer. A reflecting mirror having an intermediate film layer made of a lower oxide, and made of a higher oxide as it gets closer to the dielectric film layer. 2. An ion plating method in a vacuum container, which gradually increases the amount of O ₂ gas introduced into the vacuum container and forms a metal and a lower oxide thereof on the surface of the metal substrate in the vicinity of the substrate. A method for manufacturing a reflecting mirror, which comprises forming an intermediate film layer made of a higher oxide as the film thickness increases, and then successively forming a dielectric film layer thereon.