JP2000045944A - Pump member, turbo molecule pump, and surface treatment layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump member equipped with both good corrosion resistance and high emissivity and a turbo molecule pump, employing this pump member as the rotor, and to provide a surface treatment layer that may generally give any member the aforementioned performance. SOLUTION: A surface treatment layer S is formed on the surface of a rotor 4 that is a member of a turbo molecule pump. This surface treatment layer S comprises, as its first layer, a metal plating layer S1 that is made up of Ni-P alloy formed through electroless plating and, as its second layer, a resin layer S2 formed with an epoxy resin processed through cationic electro- deposition. An intermediate layer SM consisting of an amorphous organic metal film is placed between the metal plating layer S1 and the resin layer S2. With this configuration, corrosion resistance is improved by the metal plating layer S1 and heat dissipation performance is enhanced by the resin layer S2, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum pump used in a semiconductor process or the like, and to a pump member constituting the vacuum pump. More particularly, the present invention relates to a turbo molecular pump when the pump member corresponds to a rotor, and generally to a surface treatment layer that can be formed on an arbitrary member surface.

[0002]

2. Description of the Related Art A semiconductor process is realized by various steps including optical processing and chemical processing. A typical example of the optical processing includes an exposure processing for printing a circuit pattern on a wafer surface, and a chemical processing includes, for example,
Surface treatment such as forming a thin film on the wafer surface, etching treatment, cleaning treatment and the like can be mentioned. In order to realize these processes, an exposure apparatus is used in optical processing, and various chemicals and various devices for safely handling the chemicals are used in chemical processing. In these various processes or various apparatuses and devices, while demands for further higher integration of semiconductors are increasing, each of them is required to have a technically high level, and further development is required. Intense research and development are to be carried out in various places concerned.

[0003] In particular, if a specific technique is mentioned, paying attention to a surface treatment step as a chemical treatment, CVD (Chemical Vapor Deposition) is an essential technique in the semiconductor process as the thin film manufacturing technique described above. There is technology. The CVD is a technique in which a source gas is supplied to a substrate such as a wafer, and a desired thin film is formed on the substrate through gas adsorption and chemical reaction on the substrate. This technology is indispensable for realizing high integration of semiconductors such as thinning of gates and reduction of capacitance between wirings.

[0004] By the way, in order to realize the above-mentioned CVD, equipment for realizing a stable supply of gas,
In order for the chemical reaction on the substrate surface to proceed effectively, a device or the like for maintaining the environment that keeps the area around the substrate surface clear is required. In general, many gases used in CVD are extremely toxic, and their handling requires great care. Therefore, it is indispensable to consider gas supply equipment and equipment for recovering it. In addition, as a method of “keeping the area around the substrate surface clear”, specifically, a means for expressing a vacuum atmosphere is generally used, and therefore,
In order to realize this, an evacuation system will be prepared.

As the vacuum evacuation system, a system constituted by a plurality of pumps such as a rotary pump, a diffusion pump, and a turbo molecular pump is generally used so as to enable multi-stage evacuation from atmospheric pressure. Among them, in a vacuum exhaust system having a configuration including a turbo molecular pump, an ultra-high vacuum whose vacuum degree reaches about 10 ⁻¹⁰ Torr is realized. In addition, the turbo molecular pump is, as is well known,
It has a configuration in which gas molecules are exhausted while being compressed by a rotor rotating at about 90,000 rpm. Here, since the rotor is a member that rotates at a very high speed as described above, an aluminum alloy that is lightweight and has high stress strength is generally selected as its material.

[0006]

By the way, among the above-mentioned toxic gases in CVD, there is a corrosive gas. For example, dry chlorine gas Cl ₂ is known to corrode aluminum. On the other hand, the turbo molecular pump prepared as a vacuum evacuation system naturally also sucks gas used for CVD. The rotor constituting the turbo-molecular pump was made of an aluminum alloy as described above. As is evident from these facts, great care needs to be paid to the use of turbo molecular pumps in semiconductor processes including CVD and the like. In other words, it can be said that there is a technical problem that avoids corrosion of the rotor member due to toxic gas and always enables stable operation of the exhaust system.

[0007] Further, the technical problems relating to the turbo-molecular pump are not limited to the above circumstances. That is,
The rotor must be configured to dissipate heat more easily, that is, to have a higher emissivity. this is,
This is because a large amount of heat is generated when the rotor rotates at a very high speed as described above. Further, particularly, when a situation occurs in which the rotor sucks more gas than the assumed gas suction amount, the amount of generated heat increases dramatically. If the generated heat is left as it is, creep will be generated in the rotor rotor blades and the like, which will greatly affect the operation of the turbo molecular pump. However, on the other hand, since the turbo molecular pump is assumed to be operated at an ultra-high vacuum degree, in an atmosphere in which the rotor rotates, heat dissipation due to a convection phenomenon which can be normally expected is not promoted. Therefore, it can be said that this problem has emerged as a more serious technical problem.

[0008] The two problems mentioned above generally have conflicting characteristics in an attempt to solve them.
In other words, as a countermeasure to solve the former problem, conventionally, measures such as applying nickel plating to the rotor surface to provide corrosion resistance have been taken, but in this case, the emissivity is not sufficient and the rotor is generated. The heat could not be dissipated quickly. Conversely, with the latter challenge in mind,
Considering that a coating having a high emissivity is applied to the rotor surface, in this case, the corrosion resistance is insufficient and the gas is immediately corroded by the gas. Further, even when an attempt is made to increase the emissivity by subjecting the nickel plating surface to an oxidation treatment or the like, it is extremely difficult to obtain a sufficient emissivity, and the two problems cannot be solved simultaneously. Was.

The point is that until now, no effective means has been developed so as to solve the above two problems at once, so that practical measures are not sufficient in terms of operation of the turbo-molecular pump. This is only to call attention, and this places an extra burden on the user. The above description is not limited to the turbo-molecular pump.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a pump member having both corrosion resistance and high emissivity, and a turbo molecular pump using the pump member as a rotor. Is to provide. Another object of the present invention is to provide a surface treatment layer capable of imparting the above-described performance to an arbitrary member.

[0011]

The present invention employs the following means in order to solve the above-mentioned problems. That is, a pump member according to claim 1 has a metal plating layer formed on a base material and a resin layer formed on the metal plating layer.

This pump member can be said to have a sufficient corrosion resistance due to the metal plating layer and also have a higher emissivity than the resin layer. Therefore, this pump member cannot be expected to dissipate heat as in an ultra-high vacuum atmosphere or the like, and has a very effective action in an atmosphere where a corrosive gas flows. I can say that.

A pump member according to a second aspect is characterized in that an intermediate layer is provided between the metal plating layer and the resin layer.

According to this, it can be expected that the adhesion strength between the metal plating layer and the resin layer is sufficiently ensured by the intermediate layer. Therefore, it is possible to obtain a highly stable surface treatment layer that does not easily peel off.

According to a third aspect of the present invention, in the pump member, the metal plating layer is formed by electroless plating.

According to this, the base material and the metal plating layer are firmly attached to each other. Further, as is a concern in electroplating, there is no need to worry about a situation in which plating progresses in a portion where current is concentrated, such as a projection, and plating is unevenly formed on the entire surface of the member. That is, it is possible to form a surface treatment layer having a uniform thickness over the entire surface of the pump member.

According to a fourth aspect of the present invention, in the pump member, the resin layer is formed by cationic electrodeposition coating.

According to this, according to this, it is guaranteed that the metal plating layer or the intermediate layer and the resin layer are firmly adhered. In addition, by using the cationic electrodeposition coating, it is possible to form a uniform coating film on a pump member having a complicated shape, and a high-quality film without sagging or burn-through of the coating film. Can be formed.

According to a fifth aspect of the present invention, in the pump member, the metal plating layer is made of nickel, and the resin layer is made of epoxy resin.

According to this, a more effective action can be expected with respect to corrosion resistance and emissivity. That is, more effective resistance to corrosive gas can be exhibited, and more effective heat dissipation can be realized.

A pump member according to a sixth aspect of the present invention is characterized in that the pump member is a rotor made of an aluminum alloy as a base material.

According to this, since the pump member is a rotor, it is generally assumed that it is used in the construction of a turbo-molecular pump. Further, in a rotor that performs high-speed rotation in an atmosphere in which an ultra-high vacuum and corrosive gas is present, the effect obtained by providing the metal plating layer and the resin layer, that is, corrosion resistance,
The effect of high emissivity can be used most effectively.

According to a seventh aspect of the present invention, there is provided a turbo molecular pump, comprising: a nickel layer formed by electroless plating on a base material made of an aluminum alloy; and an epoxy resin layer formed by cation electrodeposition coating on the nickel layer. And a rotor having:

It is clear that this turbo-molecular pump can obtain the various actions described above.

In the surface treatment layer according to the present invention, the first layer is a nickel alloy layer formed by electroless plating, and the second layer is a resin layer formed by cationic electrodeposition coating of an epoxy resin. It is characterized by having.

The surface treatment layer, as described above, is composed of a uniform plating layer and a coating film having excellent functions such as corrosion resistance, high emissivity, and high adhesion strength between the layers. It can be said. Further, by forming this surface treatment layer on an arbitrary member surface which is generally exposed to an atmosphere in which the above-mentioned respective performances are required, it is possible to make the most of its action.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of the turbo-molecular pump P. In the present embodiment, a description will be given assuming that the rotor 4 shown in FIG. 1 corresponds to the pump member described in the claims. Hereinafter, first, the configuration of the turbo-molecular pump P will be described, and then the surface treatment layer S (FIG. 2) formed on the surface of the rotor 4 will be described.
The method of manufacturing the rotor 4 will be described, and the properties of the surface treatment layer S will be described.

The turbo-molecular pump P has a structure in which various devices are provided inside a casing 1 having an upper half 1a and a lower half 1b. In the casing 1, an intake port 1c is formed in an upper half 1a, and an exhaust port 1d is formed in a lower half 1b.

A rotor 4 is provided in the rotor chamber 2 inside the casing 1. The rotor 4 includes a vertically-rotated rotor shaft 4a and the rotor shaft 4a.
a) and a rotor blade 5 radially arranged around the periphery. A stationary blade 3 is fixed to the upper half 1a of the casing. Since the rotor 4 is a member that rotates at a high speed as described later, it is generally preferable to select an aluminum alloy or the like that is lightweight and has high stress strength.

At the lower end of the rotor shaft 4a, a thrust magnetic disk 6 is provided. Thrust magnetic bearings 8 are provided on the upper and lower surfaces of the thrust magnetic disk 6 so as to face the same. Radial magnetic bearings 7a and 7b are provided above and below the facing surface of the rotor shaft 4a and the casing lower half 1b, respectively.
b is provided. Further, a ball bearing 9 provided as an upper radial protection bearing is provided at an upper end portion of the rotor shaft 4a, and a ball bearing 10 provided as a lower protection bearing for radial and thrust is provided at the lower end neck portion. And the casing lower half 1b
Is provided with a motor 11 for driving the rotor.

The turbo molecular pump P in the present embodiment
As is apparent from the above configuration, the rotor has active magnetic bearings, and the rotation of the rotor 4 is realized by these and the driving force generated by the rotor driving motor 11. At this time, the rotation speed of the rotor 4 is about
At 90,000 rpm (1500 rpm), the temperature will reach about 130 ° C even during normal operation. The present invention is not limited to the configuration of the turbo-molecular pump P, and it is needless to say that the present invention is applicable to a turbo-molecular pump using a ball bearing type and other bearings.

The turbo-molecular pump P having the above structure is used, for example, as a part of an exhaust system together with a rotary pump, a diffusion pump and the like in a CVD apparatus used in a semiconductor process. In other words, it is used for the purpose of evacuating the inside of the chamber provided simultaneously with the CVD apparatus. In the CVD apparatus, a gas for causing a chemical reaction with the surface of the substrate is supplied into the chamber, and the turbo molecular pump P inevitably sucks this gas. By the way, as described above, this gas is generally toxic, and in the case of trimethylgallium Ga (CH ₃ ) ₃ or a dry chlorine gas Cl ₂ having a corrosive action on aluminum, a turbo gas is used. It can be said that the gas is particularly problematic for the molecular pump P, that is, the rotor 4 made of an aluminum alloy. In addition, in the semiconductor process, gases generally widely used include, in addition to these, monosilane Si.
H _4, phosphine PH _3, arsine AsH _3, diborane B
Examples include ₂ H ₆ , hydrogen selenide H ₂ Se, monogermane GeH ₄ , and disilane Si ₂ H ₆ .

Next, the structure of the rotor 4 will be described in detail. FIG. 2 is a partially enlarged cross-sectional view of the rotor blade 5 constituting the rotor 4. The rotor 4, that is, the moving blade 5, is made of an aluminum alloy as described above. More specifically, such as JIS2014 and JIS2618,
It is preferable to use an aluminum alloy (Al-Cu-based alloy) in the 2000 series in the JIS classification number.

A surface treatment layer S is formed on the entire surface of the rotor 4. The surface treatment layer S has a large two-layer structure as shown in the enlarged view of FIG. 2, and the first layer is a metal plating layer S1 and the second layer is a resin layer S2. In the present embodiment, the former metal plating layer S1 is made of nickel and formed by electroless plating. More specifically, Ni-P
It is formed as an alloy or a Ni-B alloy. The resin layer S2 is made of an epoxy resin formed by cationic electrodeposition.

It is preferable that the metal plating layer and the resin layer have a thickness of about 50 μm and about 20 μm, respectively. Speaking of the thickness of the metal plating layer, it is 50
If it exceeds μm, there is a possibility that the load on the rotation of the rotor 4 may be burdened. Conversely, if it is too thin, it may not be possible to obtain sufficient corrosion resistance. This is why a thickness of 50 μm is most preferred. Also,
The same applies to the thickness of the resin layer. The thickness of the surface treatment layer S as a whole (70 μm in this example) must be considered in consideration of the rotational performance of the rotor 4 as described above. Therefore, it is more preferable to make the thickness as thin as possible. It can be said that it is a state.

An intermediate layer SM is provided between the metal plating layer and the resin layer. This intermediate layer SM
Is an amorphous organometallic film formed by subjecting the surface of the metal plating layer S1 to a chemical conversion treatment using a Cr-free surface treatment agent for a coating base. Due to the presence of the intermediate layer SM, the adhesion between the metal plating layer S1 and the resin layer S2 is improved, and an effect of enhancing corrosion resistance is obtained.

The rotor 4 including such a surface treatment layer S
Will be manufactured in the following procedure. First, an aluminum alloy machined into a cylindrical shape is prepared, and the aluminum alloy is machined by a lathe or the like so that the surface of the aluminum alloy substantially matches the outer shape of the rotor 4. Then, after performing a process of roughly shaving the shapes of the plurality of rotor blades 5 from this surface,
A precise shape is finally given to each of the moving blades 5 by a method such as electric discharge machining or machining center machining. This completes the shape processing for the rotor 4 and then proceeds to the step of forming the surface treatment layer S. Therefore, the rotor 4 at this time corresponds to the “base material” in the claims.

First, the metal plating layer S1 described above is formed on the rotor 4. However, before that, rotor 4
Perform pretreatment such as cleaning and etching on the surface.
The metal plating layer S1 is formed by electroless plating, as will be described later, but this pretreatment is not specially different from that usually performed as a pretreatment for the electroless plating. If you follow the steps easily, alkaline degreasing,
The pre-processing in the present embodiment is configured by each processing of etching, smut removal, first zincate processing, zincate peeling, second zincate processing, and neutralization processing.
By the way, it goes without saying that a water washing process is inserted between the above-mentioned processes.

The formation of the metal plating layer S1 is performed by an electroless plating method after the completion of the above pretreatment and washing with water. Electroless plating is a plating method that proceeds chemically under conditions in which cathode deposition of a metal and anodic oxidation of a reducing agent occur simultaneously. That is, unlike the case where an external DC power source is provided as in the case of electroplating, the metal ions receive the electrons emitted by the reducing agent, whereby the metal deposition automatically proceeds. In the present embodiment, a Ni-P alloy is selected as the metal and is deposited on the surface of the rotor 4.

The step of electroless Ni (Ni-P) plating is specifically performed as follows. First, an aqueous solution of sodium phosphinate as a reducing agent is poured into an appropriate container. In this embodiment, Top Nicolon BL-M and BL-1 (manufactured by Okuno Pharmaceutical Co., Ltd.), which are easily available commercially, were used. The concentrations were 100 ml and 60 ml, respectively, per liter of the aqueous solution. The electroless Ni plating is completed by keeping the aqueous solution at 90 ° C. and immersing the rotor 4 for 4 hours.

In this case, unlike Ni plating by electroplating, a uniform Ni-P layer can be formed on the surface of the rotor 4. This is because the rotor 4 has an extremely complicated shape as shown in FIG. 1, and if electroplating is applied to the rotor 4, the protrusions (for example, the tip of the moving blade 5) may be formed. This is because the current is concentrated, and the plating in that portion proceeds more than in other portions, and there is a high possibility that a non-uniform plating layer is formed on the entire rotor 4. Therefore, it can be said that adopting the electroless plating method is very effective for a member having a complicated shape such as the rotor 4.

When the formation of the metal plating layer S1 is completed, a chemical conversion treatment is performed on the surface of the metal plating layer S1. This corresponds to the pretreatment of the next resin layer S2 for cationic electrodeposition coating. By performing the chemical conversion treatment, the intermediate layer SM made of the amorphous organic metal film is formed, and the adhesion between the metal plating layer S1 and the resin layer S2 is improved.
The method of forming the intermediate layer SM may be, for example, a method of performing a chemical conversion treatment which is usually performed when performing electrodeposition coating on stainless steel. For example, the intermediate layer SM is formed by the following steps. First, the surface of the metal plating layer S1 is washed and dried. Then, the entire rotor 4 is immersed for 5 to 30 seconds in an aqueous solution of Palcoat 3841 (commercial product, manufactured by Nippon Parka) whose temperature is set to about 40 ° C. from normal temperature. Finally, it is completed if this is pulled up and dried without washing with water.

When the formation of the intermediate layer SM is completed, a resin layer S2 is formed next. The formation of the resin layer S2 is performed by cationic electrodeposition coating. Cationic electrodeposition coating is a process of immersing an object in an aqueous solution in which a resin is neutralized with a neutralizing agent and ionizing it, and applying a DC voltage to apply electro-permanence, electrolysis, and electro-deposition on the object. A method of causing electro-osmosis to form a resin coating film on the object to be coated. In particular, “cation” indicates that the electrodeposition paint is in a state of being charged with a positive charge, and the mechanism for forming a coating film is based on the reaction of the isocyanate portion of the epoxy resin. In addition, there is a method called anion electrodeposition coating for this cationic electrodeposition coating, but most of the currently used in the market are cationic type because of the reason that the former has much better corrosion resistance. ing.

In this embodiment, the resin layer S2 is formed by the following steps. First, an aqueous solution containing the above-mentioned epoxy electrodeposition paint is poured into an appropriate container. A positive electrode made of graphite or the like is provided near the side wall inside the container. The rotor 4 having been subjected to the steps described above is immersed in such a container, and the rotor 4 and the positive electrode are electrically connected via a DC power supply. That is, in this case, the rotor 4 becomes a cathode. Thereafter, a distance between the positive electrode and the rotor 4 of 15
A voltage of 0 V is applied and the state is maintained for 2-3 minutes. Then, a coating film of an epoxy resin, that is, a resin layer S2 is formed on the surface of the rotor 4 by the above-described coating film forming mechanism.

In this case, as is generally said as an advantage of applying the cationic electrodeposition coating, a uniform resin layer S2 can be formed even on a rotor having a complicated shape such as the rotor 4. Further, the resin layer S is of high quality without sagging or burn-through of the coating film. In addition, the adhesion of the resin layer S2 to the base becomes extremely strong due to the presence of the intermediate layer SM.

Finally, the rotor 4 after the above process is
After performing the water washing process, a baking process is performed. Specifically, it may be carried out in a firing furnace or the like at 190 ° C. for about 30 minutes. This is performed in order to release the blocking agent immediately after the cationic electrodeposition coating and to realize the crosslinking of the coating film and to ensure the close contact of the resin layer S2.

Table 1 shows the results of measurement of the emissivity ε and the corrosion resistance test on the rotor 4 including the surface treatment layer S obtained through the above-described manufacturing process. Table 2 shows the temperature measurement results of the rotor 4 when the rotor 4 was actually operated in a vacuum atmosphere. The corrosion resistance test was evaluated by immersing the entire rotor 4 in an aqueous HCl solution and measuring the time when corrosion of the base material started.

[0048]

[Table 1]

[0049]

[Table 2]

In Tables 1 and 2, two examples to be compared with the surface treatment layer S of the present embodiment are those obtained by applying only electroless Ni plating on the base material,
In this case, an anodic oxide film is formed on a substrate. First, as can be seen from Table 1, while the emissivity ε is 0.2 in the surface treatment layer S of the present embodiment, it can be seen that ε = 0.9 is dramatically improved.
Based on this fact, when comparing the temperature measurement results in Table 2 and the present embodiment, the temperature is increased to 130 ° C. in the former, whereas it is suppressed to 100 ° C. in the present embodiment. You can see that it is. Returning to Table 1, the emissivity ε is 0.9, which is the same value as that of the present embodiment. However, in the corrosion resistance test, the corrosion of the base material started after 1 hour, whereas the surface treatment layer S of the present embodiment started. Did not start corrosion after immersion for 168 hours.

Thus, it can be seen that the surface treatment layer S in the present embodiment has both high emissivity and excellent corrosion resistance. Therefore, when the rotor 4 on which the surface treatment layer S is formed is provided in the turbo molecular pump P described above and further installed in a CVD apparatus or the like, the heat generated from the rotor 4 is reduced to an ultrahigh vacuum. It is possible to effectively dissipate even underneath, so that the possibility of the rotor blades 5 and the like being creep-damaged can be kept extremely small, and even if the rotor 4 is exposed to corrosive gas, it is easily corroded. No more. That is, the operation of the turbo molecular pump P can always be stably performed, and further, the extremely reliable semiconductor process can be supported.

In the above embodiment, the rotor 4 of the turbo molecular pump P is described as a pump member, but the present invention is not limited to this. That is, the present invention is also applicable to a pump member other than the rotor 4 that generates heat in a vacuum atmosphere and may be exposed to corrosive gas. Note that the pump member in this case is not limited to the turbo molecular pump P, but includes a pump member in a rotary pump, a diffusion pump, or the like as exemplified above.

In other words, the present invention is not limited to the pump member as long as it is a member that can be used in the above-described environment. This does not prevent the formation of the surface treatment layer S as described above to enjoy the function and effect. That is, the present invention also falls within this range.

Furthermore, the metal plating layer S1 can be replaced with a metal that can be formed by electroless plating, such as Ni-P alloy, Ni-B alloy, Cr, Co, and in some cases, Au, in addition to the above-mentioned Ni-P alloy. . As the resin layer S2, an acrylic resin may be used instead of the epoxy resin. In this case, without performing the above-mentioned cationic electrodeposition coating, the resin layer S
2 may be obtained. However, at this time, it is necessary to pay sufficient attention so that an adhesion strength such that peeling does not occur even when the rotor 4 rotates at a high speed is obtained. In any case, all of these are within the scope of the inventive concept.

[0055]

As described above, the pump member according to the first aspect has a metal plating layer formed on the base material and a resin layer formed on the upper surface thereof, so that a sufficient corrosion resistance action is obtained. It can be said that it has both the properties of high emissivity and high emissivity. Therefore, such as ultra-high vacuum,
In an environment in which heat is difficult to dissipate and an environment in which corrosive gas flows, the present pump member can exhibit an effective heat dissipation ability and an ability to oppose corrosive gas.

In the pump member according to the present invention, since the intermediate layer is provided between the metal plating layer and the resin layer, the adhesion of the two layers is sufficiently ensured by the intermediate layer.
Therefore, a highly stable surface treatment layer that does not easily peel off can be obtained.

According to the third aspect of the present invention, the metal plating layer is formed by electroless plating.
Reliable adhesion and formation of a uniform plating layer can be performed.

In the pump member according to the fourth aspect, since the resin layer is formed by cationic electrodeposition coating, it is possible to provide a high quality without a reliable adhesion, a uniform coating film formation, and sagging and burnout. It is possible to carry out formation of a coating film.

In the pump member according to the fifth aspect, since the metal plating layer is made of nickel and the resin layer is made of epoxy resin, more effective action can be expected with respect to corrosion resistance and emissivity. It is possible to make more effective use of the effects relating to the corrosion resistance effect and the heat dissipation ability.

Since the pump member according to the sixth aspect is a rotor based on an aluminum alloy, it is generally assumed that it is used in the construction of a turbo-molecular pump. Further, since the rotor in this case is a member that performs high-speed rotation in an atmosphere in which an ultra-high vacuum and corrosive gas are present, the effects obtained from the above-described effects of corrosion resistance and high emissivity are most effectively utilized. be able to. In addition, since the rotor is a member that rotates at a high speed, the function and effect of reliable adhesion can be effectively utilized at the same time.

According to a seventh aspect of the present invention, there is provided a turbo molecular pump, comprising: a nickel layer formed by electroless plating on a substrate made of an aluminum alloy; and an epoxy resin layer formed by cation electrodeposition coating on the nickel layer. And a rotor having: Therefore, this turbo molecular pump can enjoy the various effects described above, and can perform stable operation.

According to the present invention, the first layer is a nickel layer formed by electroless plating, and the second layer is a resin layer formed by cationic electrodeposition coating of an epoxy resin. I have. Therefore, this surface treatment layer has excellent effects such as corrosion resistance, high emissivity, high adhesion strength between layers, uniformity of each layer, and the like. In addition, by forming this surface treatment layer on the surface of any member generally used in a situation where each of the above-mentioned performances is required, the function and effect can be enjoyed to the maximum.

[Brief description of the drawings]

FIG. 1 is a partially sectional perspective view showing a configuration of a turbo-molecular pump.

FIG. 2 is an enlarged sectional view of a part of a rotor.

[Explanation of symbols]

 4 Rotor P Turbo molecular pump S Surface treatment layer S1 Metal plating layer S2 Resin layer

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomoaki Okamura 4-22, Kannonshinmachi, Nishi-ku, Hiroshima-shi, Hiroshima Mitsubishi Heavy Industries, Ltd. Hiroshima Works F-term (reference) 3H022 AA03 BA04 CA55 DA14 3H031 DA02 EA06 FA03 3H076 AA16 AA21 BB26 CC34

Claims (8)

[Claims] 1. A pump member comprising: a metal plating layer formed on a base material; and a resin layer formed on the metal plating layer. 2. An intermediate layer is provided between the metal plating layer and the resin layer.
The pump member according to any one of the preceding claims. 3. The pump member according to claim 1, wherein the metal plating layer is formed by electroless plating. 4. The pump member according to claim 1, wherein the resin layer is formed by cationic electrodeposition coating. 5. The pump member according to claim 1, wherein said metal plating layer is made of nickel, and said resin layer is made of epoxy resin. 6. The pump member according to claim 1, wherein the pump member is a rotor having an aluminum alloy as a base material.
The pump member according to any one of the above. 7. A rotor having a nickel layer formed by electroless plating on a base material made of an aluminum alloy, and an epoxy resin layer formed by cation electrodeposition coating on the nickel layer. The turbo molecular pump characterized by the above. 8. A surface treatment wherein the first layer is a nickel layer formed by electroless plating, and the second layer is a resin layer formed by cationic electrodeposition coating of an epoxy resin. layer.