JP5647535B2 - Vapor deposition equipment - Google Patents

Description

  The present invention relates to a vapor deposition apparatus suitable for a diffusion process for internally diffusing Dy or the like vapor deposited on the surface of a rare earth sintered magnet.

  Vapor deposition is performed to form a thin film of metal or the like on the surface of the workpiece. This vapor deposition process includes physical vapor deposition (PCV) and chemical vapor deposition (CVD), but PCV which can be relatively easily performed and has excellent controllability is widely used. Among PCVs, in particular, a vacuum deposition method is often used in which a vaporized element sublimated from a heated raw material (deposition source) is attached to the surface of a material to be processed to form a thin film or the like in a vacuum.

  For example, a vacuum deposition method is used as a diffusion treatment method in which dysprosium (Dy) once deposited on the surface of an Nd—Fe—B rare earth sintered magnet (hereinafter simply referred to as “magnet material”) that is a material to be treated is diffused. For example, there is a description related to the following patent document.

International Publication WO2006 / 100968 International Publications WO2007 / 102391 (JP2008-263223A, JP2009-124150A) JP 2008-177332 A JP 2009-43776 A

  In any of the treatments proposed in the above patent documents, a diffusion material (evaporation source) that is a diffusing element material and a magnet material that is a material to be treated are placed close to each other in the same processing furnace, and the treatment is started. From the end to the end under the same conditions. However, since the timing suitable for introduction of the diffusing element is limited, unnecessarily long heating of the diffusing material is not preferable because it causes a waste of rare Dy or the like and a decrease in production efficiency.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a vapor deposition processing apparatus capable of performing an efficient vapor deposition process without wasting a rare vapor deposition material.

  As a result of intensive research and trial and error in order to solve this problem, the present inventor newly came up with the idea of performing vapor deposition by bringing the vapor deposition source close to the material to be treated only at a time suitable for vapor deposition. By developing this result, the present invention described below has been completed.

<< Evaporation processing equipment >>
(1) That is, the deposition apparatus of the present invention, a processing chamber for accommodating the workpiece, arranged in the processing chamber, a heating pack that can be heated in a closed state encloses the該被processing material, the processing The first atmosphere adjusting means for adjusting the atmosphere in the room, the vapor deposition source chamber that can be communicated with the processing chamber and can accommodate the vapor deposition source, and the vapor deposition source is moved between the processing chamber and the vapor deposition source chamber And a proximity moving means for moving the vapor deposition source into the heating pack and bringing the vapor deposition source close to the material to be processed, and communication and blocking between the processing chamber and the vapor deposition source chamber according to the movement of the vapor deposition source. It comprises switching means for switching, second heating means for heating the vapor deposition source, and second atmosphere adjusting means for adjusting the atmosphere in the vapor deposition source chamber.

(2) According to the vapor deposition processing apparatus of the present invention, the material to be treated and the vapor deposition source can be heated independently, and the vapor deposition treatment can be performed by bringing the vapor deposition source close to the material to be treated at an appropriate time. In this way, since the vapor deposition process can be performed at a suitable timing for a suitable period, the degree of freedom in vapor deposition is significantly higher than in the prior art, and an efficient and effective vapor deposition process is possible.

(3) The operation of this vapor deposition apparatus will be described by taking as an example the case where a diffusion element is diffused into a magnet material (material to be processed). First, the processing chamber is adjusted to an appropriate atmosphere (for example, a vacuum atmosphere) by the first atmosphere adjusting means. In the processing chamber, the magnet material is heated by the first heating means to a temperature at which the diffusion rate inside the magnet material is increased. Separately from this, the second atmosphere adjusting means creates an appropriate atmosphere (for example, a vacuum atmosphere) in the vapor deposition source chamber, and in this vapor deposition source chamber, the diffusion material (vapor deposition source) is moved to a temperature at which a desired amount of vapor can be obtained. Heat by two heating means.

  At a timing suitable for the diffusion treatment, a gate provided between the processing chamber and the vapor deposition source chamber is opened by the switching means, and the material to be treated and the vapor deposition source are brought close to each other by the proximity moving means. This state is continued for a desired time to deposit a desired amount of the diffusing element on the surface of the magnet material.

  When a necessary amount of diffusing element is deposited on the surface of the magnet material, the deposition source and the material to be processed are separated by the proximity moving means, and the processing chamber, the deposition source chamber, Is closed by the switching means. After this, by continuing to heat the magnet material in the processing chamber, the diffusing element deposited on the surface is sufficiently diffused from the surface of the magnet material to the inside. In this way, the diffusion process to the magnet material is completed using the vapor deposition apparatus of the present invention.

  In addition, the heating of the magnet material in the processing chamber is more efficient when it serves not only a simple diffusion process but also a sintering process for a compact made of magnet powder.

It is a schematic diagram of a diffusion processing apparatus.

DESCRIPTION OF SYMBOLS 1 Deposition processing apparatus 10 Processing chamber 20 Deposition source chamber 30 Gate (switching means)
M Magnet material D Diffusion material

  The present invention will be described in more detail with reference to embodiments of the invention. One or two or more configurations arbitrarily selected from the configurations shown below can be added to the configuration of the present invention described above. Which embodiment is the best depends on the target, required performance, and the like.

<Processing chamber and deposition source chamber>
The processing chamber and the vapor deposition source chamber need only be a space that can be maintained in a desired atmosphere (for example, vacuum), and are not necessarily a conventional vacuum furnace, heating furnace, or the like.

<Atmosphere adjusting means>
The atmosphere in the processing chamber or the deposition source chamber is preferably a vacuum suitable for deposition. Therefore, the first atmosphere adjusting means and the second atmosphere adjusting means are respectively a first vacuum adjusting means or a second vacuum adjusting means capable of independently adjusting the degree of vacuum in the processing chamber and the degree of vacuum in the vapor deposition source chamber. Is preferred. Such an adjustment means is comprised by the vacuum pump according to a vacuum degree, and its control apparatus, for example. Note that the atmosphere in the processing chamber or the evaporation source chamber does not have to be constant throughout the processing, and may vary during the processing as necessary.

<Heating means>
(1) The heating means is preferably one that can be heated even in a vacuum atmosphere, such as a high-frequency induction heating device or an electric resistance heating device (external heating type or internal heating type). The high frequency induction heating device is suitable for heating a magnetic material. The electric resistance heating device is preferably an internal heating type that heats an object (material to be processed or a vapor deposition source) by a heating element (heater) disposed in the treatment chamber or the vapor deposition source chamber. When these heating devices are used, the object can be heated at a high temperature in a short time.

(2) Specifically, the first heating means provided in the processing chamber is preferably a heating pack that includes a heating surface including a heater and / or a reflector and surrounds the material to be processed. When the heating pack is used, the material to be processed can be efficiently heated, and since the vapor deposition element can be substantially contained in the heating pack, an efficient vapor deposition treatment can be performed.

  However, in a situation where the heating pack completely surrounds the material to be processed, the vapor deposition source cannot approach the material to be processed and the vapor deposition process cannot be performed. Therefore, it is preferable that the heating pack has an opening / closing means that opens when the vapor deposition source approaches the material to be processed by the proximity moving means and closes when the vapor deposition source separates from the material to be processed. This makes it possible to achieve both efficient heating of the material to be processed and efficient vapor deposition on the material to be processed.

  Further, in a situation where the heating pack completely surrounds the material to be processed, it is not possible to efficiently cool the material to be processed by introducing a cooling gas into the processing chamber after the vapor deposition process. Therefore, the heating pack preferably has release means for moving at least a part of the heating surface surrounding the material to be processed and releasing the surrounding of the material to be processed by the heating surface when the cooling gas is introduced by the cooling means. Thereby, it becomes possible to perform both heating and cooling of a to-be-processed material efficiently.

(3) It is preferable that the 2nd heating means which heats a vapor deposition source is a flat heater which mounts a vapor deposition source. If a flat heater is used, the vapor deposition source mounted on the mounting surface (upper surface) can be easily heated. And since there is no shielding object above the vapor deposition source, it is convenient when the vapor deposition process is performed by bringing the vapor deposition source close to the material to be treated from below. In this case, the proximity moving means can be configured by an elevator with a relatively easy structure that moves the flat heater up and down.

(4) The first temperature control means that the first heating means and the second heating means can independently adjust the temperature of the material to be processed, which is the temperature of the material to be processed, and the vapor deposition source temperature, which is the temperature of the vapor deposition source. And second temperature control means. Thereby, since a vapor deposition source can be heated independently of the heat pattern of a to-be-processed material, a vapor deposition process can be performed on suitable conditions on timely.

The present invention will be described more specifically with reference to examples. FIG. 1 shows a schematic diagram of a vapor deposition processing apparatus 1 according to an embodiment of the present invention.
<< Configuration of vapor deposition processing equipment >>
(1) The vapor deposition processing apparatus 1 communicates or shields between the processing chamber 10, the vapor deposition source chamber 20 connected to the processing chamber 10 and communicating with the processing chamber 10, and the processing chamber 10 and the vapor deposition source chamber 20. And a gate (switching means) 30.

  The processing chamber 10 is composed of a vacuum furnace to which a vacuum pump (not shown) is connected, and the inside can be adjusted to a desired degree of vacuum (first atmosphere adjusting means, first vacuum adjusting means). In the processing chamber 10, a mounting table 11 on which the material to be processed M is mounted is provided. A lower portion of the mounting table 11 is opened (not shown) so that an evaporating element flying from below can be deposited on the material M to be processed. Furthermore, a rectangular parallelepiped heating pack 13 (first heating means) is formed in the processing chamber 10 so as to surround the mounting table 11 and the material M to be processed. Each of the six surfaces of the heating pack 13 is constituted by a heating surface including a reflector and an electric resistance heating heater (hereinafter simply referred to as “heater”) attached to the reflector. A bottom surface 13a which is one heating surface of the heating pack 13 can be opened or closed by sliding or rotating. The bottom surface 13a is opened when the vapor deposition source D rising from the vapor deposition source chamber 20 approaches the workpiece M, and is otherwise closed (opening / closing means). Further, the side surface 13b, which is another heating surface of the heating pack 13, can also be opened or closed by sliding or rotating, and the enclosure of the material M to be processed by the heating pack 13 can be released (release means).

  The vapor deposition source chamber 20 is also connected to a vacuum pump (not shown), and the inside can be adjusted to a desired degree of vacuum (second atmosphere adjusting means, second vacuum adjusting means). In the vapor deposition source chamber 20, a mounting table 22 on which the vapor deposition source D is placed is provided. This mounting table 22 comprises a flat heater, and can heat the vapor deposition source D to a desired temperature (second heating means). Further, in the vapor deposition source chamber 20, an elevator 21 (proximity moving means) including a feed screw mechanism that can move the mounting table 22 up and down and bring the vapor deposition source D on the mounting table 22 close to the material M to be processed. .

  The gate 30 is slidable in the back (normal direction) of the paper surface, and allows the processing chamber 10 and the vapor deposition source chamber 20 to communicate with each other, or blocks both chambers and separates them into separate chambers. The gate 30 is opened and closed according to the elevation of the elevator 21. That is, when the elevator 21 brings the vapor deposition source D on the mounting table 22 from the vapor deposition source chamber 20 to the workpiece M in the processing chamber 10 or when the elevator 21 moves away from the processing chamber 10 to the vapor deposition source chamber 20, the gate 30 becomes an open state. Conversely, in other cases, the gate 30 is basically closed, and the processing chamber 10 and the vapor deposition source chamber 20 can be adjusted to an independent atmosphere.

(2) The heater provided on each heating surface of the heating pack 13 and the flat heater provided on the mounting table 22 are connected to a temperature control device (first temperature control means, second temperature control means) not shown, The energization amount to the heater is controlled. Thus, the temperature of the material to be processed M (temperature of the material to be processed) and the temperature of the vapor deposition source D (vapor deposition source temperature) can be independently adjusted to desired temperatures. Further, a cooling gas pipe (not shown) made of an inert gas such as Ar is connected in the processing chamber 10. By adjusting the amount of the cooling gas introduced into the processing chamber 10 by a flow rate control device (not shown), the material to be processed M can be cooled at a desired cooling rate (cooling means). During this cooling, the side surface 13b of the heating pack 13 described above is released.

(3) In addition to the processing chamber 10 and the vapor deposition source chamber 20, the vapor deposition processing apparatus 1 may further include a sub chamber for pre-processing the material to be processed M and adjusting the sample. By providing the sub chamber, a large number or a large amount of the material to be processed M can be processed efficiently.

  Further, in the above-described vapor deposition processing apparatus 1, the case where the processing chamber 10 and the vapor deposition source chamber 20 are each provided as an example, but a plurality of the processing chambers 10 are provided, and one vapor deposition source D is applied to the material M to be processed in each processing chamber 10. These may be vapor-deposited in close proximity. Furthermore, the material to be processed M may be continuously moved between the processing chamber 10 and the vapor deposition source chamber 20 so that the vapor deposition processing is performed efficiently.

<< Usage example of vapor deposition processing equipment >>
A case will be described in which an NdFeB rare earth sintered magnet in which Dy is diffused on the surface and inside is manufactured using the above-described vapor deposition apparatus 1. First, a molded body m (magnet material) obtained by molding an NdFeB rare earth magnet powder as the material to be treated M, and a metal lump d (diffusion material) made of Dy alone as a deposition source D are prepared. Then, the compact m is set on the mounting table 11 in the processing chamber 10, and the metal mass d is set on the mounting table 22 in the vapor deposition source chamber 20. Thereafter, each vacuum pump separately connected to the processing chamber 10 and the vapor deposition source chamber 20 is operated to bring each chamber to a predetermined degree of vacuum. When each chamber has a desired vacuum atmosphere, the heaters provided on the heating pack 13 and the mounting table 22 are energized to heat the compact m and the metal lump d. At this time, the compact m is heated along a preset sintering pattern, and the metal mass d is heated to a temperature at which a desired Dy evaporation amount is obtained.

  When the temperature of the molded body m (temperature of the material to be processed) reaches a temperature suitable for the internal diffusion of Dy, the gate 30 and the bottom surface 13a of the heating pack 13 are opened, the elevator 21 is operated, and the metal lump d is placed at a predetermined position. Until it is close to the compact m. When this proximity state is continued for a certain time, Dy evaporated from the metal lump d adheres to the entire surface of the molded body m. The adhering Dy further diffuses into the heated compact m (grain boundary).

  When the required amount of Dy is deposited on the magnet material, the elevator 21 lowers the mounting table 22 and separates the metal mass d from the compact m. When the metal lump d is retreated to the vapor deposition source chamber 20, the gate 30 and the bottom surface 13a of the heating pack 13 are closed. In this way, it is possible to efficiently deposit and diffuse the necessary and sufficient Dy into the molded body m at a suitable timing while suppressing the amount of rare Dy used.

  Incidentally, when the molded body m after the vapor deposition treatment is further heated in the processing chamber 10, Dy adhering to the surface is internally diffused, or liquid phase sintering between the constituent particles of the rare earth magnet powder proceeds. To do. When the molded body m after heating is cooled, a rare earth sintered magnet which is a sintered body of the molded body m is obtained. The cooling at this time is performed by opening the side surface 13 b of the heating pack 13 and introducing the cooling gas into the processing chamber 10. As a result, the rare earth sintered magnet is rapidly cooled, the coarsening of crystal grains is suppressed, and high magnetic properties are exhibited.

  Thus, the vapor deposition processing apparatus 1 which concerns on this invention can be utilized as a sintering diffusion processing apparatus of a rare earth sintered magnet.

Claims (8)

A processing chamber for storing the material to be processed;
Is disposed in the process chamber, a heating pack that can be heated in a closed state encloses the該被processing material,
First atmosphere adjusting means for adjusting the atmosphere in the processing chamber;
A deposition source chamber that is provided so as to be able to communicate with the processing chamber and can accommodate a deposition source;
Proximity moving means capable of moving the vapor deposition source between the processing chamber and the vapor deposition source chamber and moving the vapor deposition source into the heating pack so as to be close to the material to be processed;
Switching means for switching communication and blocking between the processing chamber and the vapor deposition source chamber according to the movement of the vapor deposition source;
A second heating means for heating the vapor deposition source;
And a second atmosphere adjusting means for adjusting the atmosphere in the deposition source chamber.   The said heat pack is a vapor deposition processing apparatus of Claim 1 comprised by the heating surface which consists of a heater and / or a reflector.   The vapor deposition apparatus according to claim 2, wherein the heating pack has an opening / closing means that opens when the vapor deposition source approaches the material to be processed and closes when the vapor deposition source separates from the material to be processed. Furthermore, it comprises a cooling means for cooling the workpiece after heating by introducing a cooling gas into the processing chamber,
The vapor deposition apparatus according to claim 3, wherein the heating pack has release means for moving at least a part of the heating surface to release the sealed state of the material to be processed when the cooling gas is introduced.   The vapor deposition apparatus according to claim 1, wherein the second heating unit includes a flat heater on which the vapor deposition source can be placed.   The first atmosphere adjusting means and the second atmosphere adjusting means are respectively a first vacuum adjusting means and a second vacuum adjusting means capable of independently adjusting the degree of vacuum in the processing chamber and the degree of vacuum in the vapor deposition source chamber. The vapor deposition processing apparatus according to claim 1 or 5.   The first heating means and the second heating means are respectively a first temperature control capable of independently adjusting a material temperature to be processed which is a temperature of the material to be processed and a vapor deposition source temperature which is a temperature of the vapor deposition source. The vapor deposition apparatus of Claim 1 or 6 which has a means and a 2nd temperature control means. The material to be treated is a magnet material,
The vapor deposition processing apparatus according to claim 1, wherein the vapor deposition source is a diffusion material made of a diffusion element that diffuses from the surface of the magnet material to the inside.

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