JP6879187B2 - Plasma device jig - Google Patents

Description

The present invention relates to a jig for a plasma device.

A plasma device has been developed in which a work to be treated is subjected to plasma treatment and a film or etching is performed on a part of the surface of the work (see, for example, Patent Documents 1 and 2).

JP-A-2017-197837 Japanese Unexamined Patent Publication No. 2017-197778

In the invention described in Patent Document 1, the upper and lower parts of the work end are sandwiched between masking jigs, and plasma treatment is performed in the chamber. At this time, since the work and the masking jig belong to the negative electrode potential, and the pallet and the chamber supporting the work and the masking jig belong to the ground potential, a porcelain is arranged on the outer periphery of the masking jig, and the masking jig and the pallet are arranged. And need to be insulated.

However, if the insulator is exposed during the plasma treatment in the chamber, the electric charge accumulated on the insulator surface is released into the plasma, which may cause an abnormal discharge. For this reason, plasma cannot be generated at the outer peripheral portion of the masking jig where the insulator is exposed, and heat unevenness may occur in the work during the plasma processing, causing the work to warp.

The present invention has been made to solve such a problem, and even if the insulator is exposed during plasma processing in the chamber, an abnormal discharge occurs between the masking jig and the pallet through the insulator. It is an object of the present invention to provide a jig for a plasma device that does not occur.

The jig of the plasma device according to the present invention includes a masking jig having a first connecting member and a pallet having a second connecting member to support the work and the masking jig while masking a part of the work. The pallet has an opening in the center, the work and the masking jig are arranged inside the opening, and the first connecting member is provided with a porcelain arranged between the first connecting member and the second connecting member. The masking jig and the pallet are connected by the second connecting member and the pallet, and the porcelain has a main body portion having a spread corresponding to the facing region between the first connecting member and the second connecting member, and the first one. It has a convex portion whose tip abuts on the connecting member and the second connecting member, respectively.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a jig for a plasma device in which an abnormal discharge does not occur between a masking jig and a pallet via the insulator even if the insulator is exposed during plasma processing in the chamber. it can.

It is a perspective view which shows the jig 1 of the plasma apparatus which concerns on embodiment. It is sectional drawing of the masking jig 2, the pallet 5, and the insulators 6 and 7 along the line AA'in FIG. It is a perspective view which shows the insulator 6 which concerns on embodiment. It is sectional drawing of the jig 11 of the plasma apparatus which is a reference example. It is sectional drawing of the jig 11 of the plasma apparatus which is a reference example. It is sectional drawing of the jig 11 of the plasma apparatus which is a reference example. It is a figure which shows the discharge level of the plasma apparatus when the jig 1 of the plasma apparatus which concerns on embodiment is used. It is sectional drawing of the jig 101 of the plasma apparatus which concerns on modification 1. FIG. It is a perspective view which shows the insulator which concerns on the modification 2. It is a perspective view which shows the insulator which concerns on the modification 3.

Hereinafter, the jig of the plasma device according to the present embodiment will be described with reference to the drawings.
The plasma device according to the present embodiment is a plasma CVD device that applies a carbon coating to a work that serves as a separator for a fuel cell.
Generally, a plasma device includes a vacuum chamber, a vacuum pump, a power source, a gas supply device, and the like, and is automatically operated by a program. However, the configuration and operation of the entire device are described in detail in Patent Documents 1 and 2. Here, the illustration and description will be omitted.

FIG. 1 is a perspective view showing a jig 1 of a plasma device according to the present embodiment.
The jig 1 includes a masking jig 2, a pallet 5, and an insulator (not shown).
The masking jig 2 is also called a floating island jig, and both are composed of a conductive lower masking jig 3 and an upper masking jig 4. The masking jig 2 serves as a cathode during plasma processing, and a voltage of -3000 V is applied. The masking jig 2 may be composed of only one of the lower masking jig 3 and the upper masking jig 4.

The pallet 5 is made of a metal plate-shaped member, has an opening in the center thereof, and supports a work (not shown) and a masking jig 2 inside the opening via an insulator. Further, the pallet 5 serves as an anode during plasma processing and is connected to the ground (0V).
In FIG. 1, the seal member 8 is shown on the pallet 5 around the opening. The seal member 8 is, for example, an O-ring that is arranged between the pallet 5 and the upper and lower vacuum chambers when the pallet 5 is sandwiched between the upper and lower vacuum chambers to maintain the airtightness of the vacuum chambers. Is.

FIG. 2 is a cross-sectional view of the masking jig 2, the pallet 5, and the insulators 6 and 7 along the line AA'of FIG.
As described above, the masking jig 2 is composed of the lower masking jig 3 and the upper masking jig 4. Further, the lower masking jig 3 and the upper masking jig 4 have positioning blocks (first connecting members) 31 and 41, respectively.

In the masking jig 2, a work (not shown) is placed on the lower masking jig 3, the upper masking jig 4 is placed on the work, and the lower masking jig 3 and the upper masking jig 4 are used. Mask the end of the work by sandwiching the end of the work.

As described above, the pallet 5 supports the work and the masking jig 2 via the insulators 6 and 7. For this purpose, the pallet 5 has positioning blocks (second connecting members) 51 and 52. The positioning block 51 is connected to the positioning block 31 via an insulator 6 to determine the position of the lower masking jig 3. The positioning block 52 is connected to the positioning block 41 via an insulator 7 to determine the position of the upper masking jig 4.

The insulators 6 and 7 are made of ceramics such as alumina or silicon dioxide, and are composed of main body portions 61 and 71 and convex portions 62 and 72. The cross sections of the insulators 6 and 7 are substantially cross-shaped.
The convex portions 62, 72 of the insulators 6 and 7 abut or fit with the concave portions of the positioning blocks 51, 52, 31, 41 at the tip thereof.

The main bodies 61 and 71 of the insulators 6 and 7 have a spread corresponding to the region where the positioning blocks 51 and 52 and the positioning blocks 31 and 41 face each other. That is, it is equivalent to the region where the positioning block 51 and the positioning block 31 overlap and the region where the positioning block 52 and the positioning block 41 overlap when the configuration shown in FIG. 2 is viewed from above (that is, when viewed through a plane). The main bodies 61 and 71 have a size of the above or a size that protrudes from the region.

FIG. 3 is a perspective view showing the insulator 6 according to the present embodiment.
The insulator 6 also has a disk-shaped convex portion 62 on each of the upper and lower surfaces of the disk-shaped main body portion 61 having a large spread. The insulator 7 also has the same shape as the insulator 6, and the illustration and description thereof are omitted here.

With this configuration, the jig 1 of the plasma device according to the present embodiment can be combined with the masking jig 2 via the insulators 6 and 7 even if the insulators 6 and 7 are exposed during the plasma processing in the chamber. It has an excellent effect that an abnormal discharge does not occur between the pallet 5 and the pallet 5.
Therefore, plasma can be generated even in the outer peripheral portion of the masking jig 2, and the work does not warp due to heat unevenness in the work.

Next, the reason why the jig 1 of the plasma device according to the present embodiment exerts the above-mentioned excellent effect will be described.
In general, there are three reasons why abnormal discharge occurs between the masking jig and the pallet via the insulator: creepage discharge, triple point, and spark discharge.

The creeping discharge means that the electrons emitted from the masking jig travel along the surface of the insulator and reach the pallet, causing a short circuit between the masking jig and the pallet. Insulators have the property of passing an electric current on their surface up to a certain distance. As a countermeasure, in general, the insulator itself is lengthened, and the surface of the insulator is made into a complicated shape such as a wavy shape to lengthen the creepage distance between the masking jig and the pallet along the surface of the insulator to prevent a short circuit. , This makes the insulator large and complicated.

FIG. 4 is a cross-sectional view of the jig 11 of the plasma device which is a reference example. In the jig 11, the insulator 7 of the jig 1 of the plasma device according to the present embodiment is left as it is, and only the insulator 6 is replaced with the cylindrical insulator 16.
The reason why creeping discharge does not occur in the jig 1 of the plasma device according to the present embodiment will be described by using the jig 11 of the plasma device.

Since the insulator 16 has no lateral spread in its main body, the creepage distance of the insulator 16 is equal to the linear distance from the positioning block 51 of the pallet 5 to the positioning block 31 of the lower masking jig 3, which is extremely short. There is a high possibility that creeping discharge will occur between the positioning block 51 and the positioning block 31.

On the other hand, in the insulator 7, the main body 71 has a lateral spread, and the creepage distance of the insulator 7 is a straight line distance from the positioning block 52 of the pallet 5 to the positioning block 41 of the upper masking jig 4. A distance twice the length from the outer peripheral end of the convex portion 72 of the main body 71 to the outer peripheral end of the main body 71 is added, and the distance becomes longer, so that the possibility of creeping discharge between the positioning block 52 and the positioning block 41 becomes smaller. ..

That is, in the jig 1 of the plasma device according to the present embodiment, since the main bodies 61 and 71 of the insulators 6 and 7 have lateral spreads, the upper and lower masking jigs 3 from the positioning blocks 51 and 52 of the pallet 5 The creepage distance to the positioning blocks 31, 41 of 4 and 4 becomes large, and the possibility that creepage discharge occurs is small.

The triple point is a point where the masking jig, the porcelain, and the plasma come into contact with each other, and the electrons emitted from the masking jig (cathode) are accumulated on the surface of the porcelain near the triple point. When the electrons cannot be accumulated in the vicinity of the triple point, the electrons are suddenly emitted into the plasma space and an abnormal discharge occurs. As a countermeasure, in general, the insulator is carved to create a narrow and minute gap between the masking jig and the insulator so that the plasma does not reach the contact point between the masking jig and the insulator. , The insulator itself must be enlarged.

FIG. 5 is also a cross-sectional view of the jig 11 of the plasma device, which is also a reference example. The jig 11 in FIG. 5 is the same as that in FIG.
The reason why the abnormal discharge due to the triple point does not occur in the jig 1 of the plasma device according to the present embodiment will be described by using the jig 11 of the plasma device.

Since the insulator 16 does not spread laterally in its main body, plasma easily enters the space formed by the positioning block 51 of the pallet 5, the positioning block 31 of the lower masking jig 3, and the insulator 16. , The state in which the triple point is formed continues for a long time, and there is a high possibility that an abnormal discharge will occur.

Note that FIG. 5 shows a state in which plasma enters only the left portion of the space formed by the positioning block 51, the positioning block 31, and the insulator 16 in order to make the figure and the description easy to understand. However, in reality, plasma enters the entire space, and plasma is also generated in other spaces.

On the other hand, in the insulator 7, the main body 71 has a lateral spread, and the upper and lower surfaces of the main body 71 have convex portions 72. Therefore, the positioning block 41 of the upper masking jig 4 and the insulator 7 For example, a fine gap of 1.5 μm or less is formed between them. Even if plasma enters this gap, it cannot reach the depth where the upper masking jig 4 and the insulator 7 come into contact with each other, and the formation of triple points is prevented.

That is, in the jig 1 of the plasma device according to the present embodiment, the main bodies 61 and 71 of the insulators 6 and 7 have lateral spreads, and the upper and lower surfaces of the main body 71 have convex portions 72, so that masking is performed. A minute gap is formed between the jigs 3 and 4 and the insulators 6 and 7, and the plasma does not reach the contact point between the masking jigs 3 and 4 and the insulators 6 and 7, and an abnormal discharge due to the triple point may occur. The sex is small.

In addition, spark discharge means that when the distance between the masking jig and the pallet is small, the electrons emitted from the masking jig travel through the space and reach the pallet to form lightning (arc), and the masking jig and pallet Is short-circuited. As a countermeasure, the distance between the masking jig and the pallet is generally increased, but for this purpose, the insulator must also be increased.

FIG. 6 is a cross-sectional view of the jig 11 of the plasma device which is a reference example. The jig 11 in FIG. 6 is the same as that in FIGS. 4 and 5.
The reason why spark discharge does not occur in the jig 1 of the plasma device according to the present embodiment will be described by using the jig 11 of the plasma device.

Since the main body of the insulator 16 does not spread in the lateral direction, there is a high possibility that the positioning block 51 of the pallet 5 and the positioning block 31 of the lower masking jig 3 face each other to generate a spark discharge.
In addition, also in FIG. 6, in order to make the explanation easy to understand, a state in which plasma is generated only in the left side portion of the space formed by the positioning block 51, the positioning block 31, and the insulator 16 is shown. However, in reality, plasma is also generated in other spaces.

On the other hand, in the insulator 7, the main body 71 has a lateral spread, and the size thereof is an area where the positioning block 52 of the pallet 5 and the positioning block 41 of the upper masking jig 4 overlap as described above. Is equivalent to or extends beyond the area. Therefore, the main body 71 of the insulator 7 exists between the positioning block 52 and the positioning block 41, the positioning block 52 and the positioning block 41 do not face each other, and the possibility of spark discharge is small. ..

That is, in the jig 1 of the plasma device according to the present embodiment, since the main bodies 61 and 71 of the insulators 6 and 7 have lateral spreads, the positioning blocks 51 and 52 of the pallet 5 and the upper and lower masking jigs. The main bodies 61 and 71 of the insulators 6 and 7 exist between the positioning blocks 31 and 41 of the 3 and 4, and the positioning blocks 51 and 52 and the positioning blocks 31 and 41 do not face each other, and spark discharge occurs. It is unlikely to occur.

In this way, the jig 1 of the plasma device according to the present embodiment suppresses three of creeping discharge, triple point, and spark discharge, and is interposed between the masking jigs 3 and 4 and the pallet 5. It prevents the occurrence of abnormal discharge, and as a result, it also has an excellent effect of obtaining a stable plasma discharge.

FIG. 7 is a diagram showing the discharge level of the plasma device when the jig 1 of the plasma device according to the present embodiment is used. The horizontal axis shows the pressure in the chamber, and the vertical axis shows the applied voltage.
Compared with the discharge level in the conventional local chamber, the discharge level according to the present embodiment can increase both the pressure in the chamber and the applied voltage.
At this time, the pressure in the chamber and the processing time have an inversely proportional relationship, and the plasma treatment according to the present embodiment enables processing in half the conventional time. Further, the applied voltage contributes to increasing the plasma intensity, and the efficiency of using the raw material gas can be improved up to about 1.2 times.

The jig 1 of the plasma device according to the present embodiment can be variously deformed and modified.
FIG. 8 is a cross-sectional view of the jig 101 of the plasma device according to the first modification. Only the cross sections of the pallet positioning block 151, the insulator 106, and the masking jig positioning block 121 are extracted and shown.
The insulator 106 according to the first modification has a flat plate shape with no convex portions on the upper and lower surfaces of the main body, and instead, the positioning block 151 and the positioning block 121 have convex portions on the upper surface or the lower surface, and their tips thereof. The portion is in contact with the insulator 106.

Even with such a configuration, the creepage distance of the insulator 106 becomes large, a minute gap is created between the masking jig and the insulator 106, and the pallet and the masking jig do not face each other. Abnormal discharge through the insulator between the tool and the pallet can be suppressed.
Since the creepage distance of the insulator 106 according to the first modification is slightly smaller than that of the insulators 6 and 7 according to the embodiment, the spread of the insulator 106 (area of the upper and lower surfaces) is further increased as necessary. You may make it larger.

FIG. 9 is a perspective view showing the insulator according to the modified example 2.
As long as the abnormal discharge between the masking jig and the pallet via the insulator can be suppressed, the main body and the convex portion of the insulator do not necessarily have to be disk-shaped or cylindrical, and are shown in FIG. 9, for example. As described above, the shape may be a polygonal flat plate shape such as a hexagonal flat plate shape, a tetragonal flat plate shape, a hexagonal pillar shape, a tetragonal pillar shape, or a polygonal pillar shape. Of course, different flat plate shapes, pillar shapes, etc. may be used between the main body and the convex portion, such as the main body portion having a disk shape and the convex portion having a hexagonal pillar shape.

FIG. 10 is a perspective view showing the insulator according to the modified example 3.
The insulator does not necessarily have to be formed as one component, that is, integrally as long as it can form a main body portion and a convex portion when combined.

As described above, the jig 1 of the plasma device according to the present embodiment masks a part of the work and is connected to the masking jigs 3 and 4 having the first connecting members 31 and 41 and the second connection. A pallet 5 having members 51 and 52 to support the workpieces and masking jigs 3 and 4, and insulators 6 and 7 arranged between the first connecting members 31 and 41 and the second connecting members 51 and 52. The pallet 5 has an opening in the center, and the workpieces and masking jigs 3 and 4 are arranged inside the opening, and the first connecting members 31, 41 and the second connecting members 51, 52 are arranged. The masking jigs 3 and 4 and the pallet 5 are connected by the insulators 6 and 7, and the insulators 6 and 7 spread corresponding to the facing region between the first connecting members 31 and 41 and the second connecting members 51 and 52. It has a main body portion having an insulator, and convex portions 62 and 72 whose tips abut against the first connecting members 31, 41 and the second connecting members 51 and 52, respectively.

With such a configuration, even if the insulators 6 and 7 are exposed during the plasma treatment in the chamber, an abnormal discharge may occur between the masking jigs 3 and 4 and the pallet 5 via the insulators 6 and 7. Absent.

1,11,101 Plasma device jig 2 Masking jig 3 Lower masking jig 31,131 Positioning block of lower masking jig (first connection member)
4 Upper masking jig 41 Positioning block of upper masking jig (first connection member)
5 Pallet 51, 52, 151 Pallet positioning block (second connecting member)
6,7,16,106 Insulator 61,71 Insulator body 62,72 Insulator convex 8 Seal member

Claims (1)

A masking jig that masks a part of the work and has a first connecting member,
A pallet having a second connecting member and supporting the work and the masking jig,
An insulator arranged between the first connecting member and the second connecting member is provided.
The pallet has an opening in the center
The work and the masking jig are arranged inside the opening.
The masking jig and the pallet are connected by the first connecting member, the second connecting member, and the insulator.
The insulator has a main body portion having a spread corresponding to a region facing the first connecting member and the second connecting member, and a convex portion whose tip abuts on the first connecting member and the second connecting member, respectively. Insulator for plasma equipment with and.

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