JP2014118610A - Work holder and film formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work holder and a film formation device such that momentary separation of a work from a work holder is eliminated, an abnormal discharge between the work and work holder can be suppressed by enhancing conductivity between the work and work holder, and a film which is more uniform than before can be formed.SOLUTION: A work holder 9 is so installed as to rotate or revolve, and a work W1 having its one end part W1a housed and held in a recessed part 9a is applied with a voltage to be heated at a necessary temperature in contact with a raw material gas, so that a coating is formed on the work W1 except at the one end part W1a. The recessed part 9a is formed large enough to have a predetermined gap at a periphery of the one end part W1a of the work W1, and a spacer 10 is provided to fill the gap, the spacer 10 being formed including a material which has electric conductivity and a larger coefficient of linear expansion than the work holder 9.

Description

  The present invention relates to a work holder and a film forming apparatus using the work holder.

  Patent Document 1 discloses a masking jig for thermal spraying on which a DLC film excellent in high hardness, high wear resistance, low friction, seizure resistance, high insulation, and the like is formed.

  Patent Document 2 discloses a method for forming a DLC film. In this film forming method, plasma is generated in a vacuum deposition chamber, a material gas is supplied, the film formation body is heated to a temperature of the material gas, and a pulse voltage is applied to the film formation body to form a DLC film.

  In addition, in the conventional film forming technique, it is generally performed to form a DLC film on a workpiece having various shapes. A method capable of performing a large amount of processing to form a DLC film on the remaining portion of the rod-like workpiece excluding one end portion has been performed.

  In this method, a work holder having a short shaft shape is placed and connected to a holder support shaft, one end of the work is inserted into a recess recessed from the upper surface of the work holder, and the lower end surface of the work and the bottom surface of the recess of the work holder A DLC film is formed by applying a voltage of −50 to 1000 V to the workpiece while maintaining electrical conductivity, and rotating and revolving.

JP 2011-241442 A JP 2012-036438 A

  According to the method for forming the DLC film on the rod-shaped workpiece described above, there is a slight gap between one end of the workpiece and the inner peripheral surface of the recess of the workpiece holder. Therefore, in this film forming method, there is a possibility that the DLC film cannot be formed uniformly when the rotation and revolution force acts on the work during film formation and the work is rattled with respect to the work holder. More specifically, since the contact area that retains the conductivity between the workpiece and the work holder is a point contact, if the workpiece becomes loose with respect to the work holder during film formation, the conductivity between the workpiece and the work holder is reduced. There is a case where the contact area that holds is momentarily separated.

  At this time, since the workpiece becomes 0 v and −50 to 1000 v remains applied to the work holder, a large potential difference is induced between the open end of the concave portion of the work holder and the lower end of the large-diameter portion of the work, thereby causing abnormal discharge. Will occur. For this reason, the DLC film formed on the large-diameter portion of the workpiece has a discharge trace near the lower end of the large-diameter portion of the workpiece, and the film quality becomes non-uniform around the discharge trace.

  The present invention has been made in order to solve such a problem, and it is possible to form a uniform film by preventing the work from instantaneously leaving the work holder during film formation and suppressing abnormal discharge. An object is to provide a holder and a film forming apparatus.

  In order to achieve the above-mentioned object, the work holder according to the present invention is provided to rotate at least one of (1) rotation and revolution, and accommodates and holds one end of the work in the recess, and voltage is applied to the work. Is applied to the material gas and heated to a required temperature to form a film on a portion other than one end of the workpiece, the recess has a size having a predetermined gap around one end of the workpiece. The spacer is formed and includes a spacer that fills the gap, and the spacer includes a material having conductivity and a linear expansion coefficient larger than that of the work holder.

  With this configuration, the work holder according to the present invention allows the spacer to be loosely inserted into the concave portion of the work holder, and the work to be loosely inserted inside the spacer. The spacer and the work holder are in close contact with each other, and the conductivity between the work and the work holder is improved.

  For this reason, abnormal discharge between a workpiece | work and a workpiece holder can be suppressed, the voltage applied to a workpiece | work holder is transmitted to a workpiece | work via a spacer, and a more uniform film can be formed compared with the past.

  The work holder which concerns on this invention is a work holder as described in said (1), (2) The said spacer has the structure provided with the slit along the generatrix direction on one side.

  With this configuration, when the work holder according to the present invention reduces the diameter by pinching the outer peripheral surface of the spacer with a pinching tool such as pliers and inserts the spacer into the concave portion of the work holder, the spacer expands to increase the diameter of the work holder. It will be in the state closely_contact | adhered to the recessed part.

  In the spacer, the thermal expansion in the circumferential direction during film formation increases the outer diameter and inner diameter. After the outer surface is brought into close contact with the inner surface of the concave portion of the work holder due to thermal expansion, the outer diameter cannot be increased, and the thermal expansion change in the circumferential direction that narrows the slit and the thermal expansion change in the direction that reduces the inner diameter. Produce. When the spacer is brought into close contact with the workpiece due to a thermal expansion change in the direction of reducing the inner diameter, the spacer becomes a crisp and increases the adhesion. Thereby, a workpiece | work, a spacer, and a workpiece | work holder will be in contact | adherence state. In the spacer, since the thermal expansion in the circumferential direction changes the slit, the abnormal increase in stress can be avoided.

  If the spacer is provided with a slit, the inner diameter of the spacer can be made sufficiently larger than the diameter of one end of the work, so that the work can be more easily inserted into the inner space of the spacer. The work of taking out the workpiece after film formation can be easily performed without the removal of the spacer, which is more advantageous when a large amount of processing is performed. Thus, the spacer can be easily taken out.

  In order to achieve the above object, the film forming apparatus according to the present invention is (3) provided in the chamber so as to rotate at least one of rotation and revolution, and has a recess. And a workpiece holder that accommodates and holds one end of the workpiece, rotates the workpiece, applies a voltage to the workpiece, and forms a coating, wherein the workpiece holder is the above (1) or (2) It has the structure provided with the work holder in any one.

  With this configuration, in the film forming apparatus according to the present invention, the spacer is thermally expanded during film formation, and the workpiece, the spacer, and the workpiece holder are in a tight contact state, and the conductivity between the workpiece and the workpiece holder is improved. Therefore, it is possible to suppress abnormal discharge between the work and the work holder that has occurred in the past.

  Therefore, the film forming apparatus according to the present invention can form a more uniform film than the conventional one. Also, when performing a large amount of processing, the work insertion work inside the spacer, The work can be easily taken out without being extracted.

  ADVANTAGE OF THE INVENTION According to this invention, the workpiece | work holder and film forming apparatus which can form a uniform film | membrane without the workpiece | work leaving | separating from a workpiece holder instantaneously during film-forming and suppressing abnormal discharge can be provided.

1 is a schematic principle diagram of a work holder according to an embodiment of the present invention and a film forming apparatus using the work holder. It is a longitudinal cross-sectional view which expands and shows the workpiece | work holding | maintenance part at the time of room temperature of the film forming apparatus which concerns on embodiment of this invention. The spacer assembled in the work holder of the film formation apparatus of FIG. 2 is shown, (A) is the front view, (B) is an end view. It is a schematic diagram which shows that DLC coating is performed to a workpiece | work by the AIP-CVD method using the film forming apparatus which concerns on embodiment of this invention at a molecular level. It is a longitudinal cross-sectional view which shows the state which the spacer of the workpiece holding part shown in FIG. 2 expanded thermally during film-forming. It is a copy of the photograph which shows the DLC film formed into a film by the film forming apparatus using the work holder which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows the workpiece holding part which concerns on the conventional film formation apparatus. It is a copy of the photograph which shows the DLC film formed into a film by the conventional film formation apparatus.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of a work holder and a film forming apparatus using the work holder according to the invention will be described with reference to the drawings.

  In this embodiment, a film forming apparatus that performs DLC coating using an arc ion plating-chemical vapor deposition method, so-called AIP-CVD method, is shown.

  FIG. 1 is a schematic principle diagram of a film forming apparatus 100 according to an embodiment. The film forming apparatus 100 includes a chamber 1 for performing a vacuum arc discharge in which the inside is evacuated, a raw material gas is supplied and a target is a cathode, and a plurality of work holders 9 provided in the chamber 1. A work rotating means 5 for holding and rotating W1 is provided.

  The chamber 1 includes a gas inlet 2 at a lower portion of one side surface portion, and is connected to, for example, an acetylene gas cylinder as a gas supply means (not shown) that is externally installed. A gas outlet 3 for discharging the lean gas is provided, and the gas outlet 3 is connected to a lean gas recovery means (not shown). Note that the lean gas recovery means may include an aftertreatment device.

  As described above, since the chamber 1 includes the gas inlet 2, the gas outlet 3, and the acetylene gas cylinder, the acetylene gas is supplied into the chamber at a constant flow rate, and the acetylene gas is consumed for forming the DLC film. It is replenished so that the concentration is always constant.

  The gas outlet 3 is switched and connected to a vacuum generator (not shown) instead of the lean gas recovery means. Thus, the chamber 1 is configured to be evacuated by introducing the inert gas from the gas inlet 2 and connecting the gas outlet 3 to the vacuum generator, and when the degree of vacuum is increased. A raw material gas involved in film formation is supplied from the gas cylinder.

  One or more titanium substrates 4 as target metals are provided on one side surface of the chamber 1 opposite to the gas inlet 2, and a current of, for example, 100 amperes flows through the titanium substrate 4.

  The work rotating means 5 is provided at the bottom of the chamber 1 and is provided by a rotary table 6 that is rotated by a motor (not shown) and a lower end portion that is rotatably supported by the rotary table 6 and extends above the rotary table 6. As the rotary table 6 rotates, a plurality of rotating shafts 7 are provided that rotate by being transmitted with a part of the rotational power. Therefore, the rotating shaft 7 rotates and revolves around the rotating table 6.

  The work rotating means 5 further includes a plurality of work holder tables 8 provided in a plurality of stages in a flange shape on each rotary shaft 7, and a plurality of work holders 9 erected on each work holder table 8. ing.

  Accordingly, each work holder 9 is revolved in a small rotation around the corresponding rotation shaft 7 and is revolved in a large rotation by the rotary table 6. In addition, the work holder 9 at the center position of the uppermost work holder table 8 is revolved by the rotary table 6 on the large rotation, and is rotated instead of the small rotation.

  Although not shown, a terminal is provided which is in sliding contact with the shaft portion of the rotary table 6 and electrically connected to the shaft portion, and this terminal can be set to a desired voltage between, for example, −50 to 1000 V. Connected to the cathode. The shaft portion of the rotary table 6, the rotary shaft 7, the work holder table 8, and the work holder 9 are integrally assembled so as to be conductive, and are assembled in a conductive state so as to be detachable with respect to the rotary table 6. Therefore, the work rotating means 5 is configured to be able to apply a voltage of −500 V, for example, while causing the work W1 held by the work holder 9 to perform the combined revolution of the small turn and the large turn.

  As shown in FIG. 2, the work holder 9 has a concave portion 9 a that is recessed from the upper end into a cylindrical space shape. The concave portion 9 a has conductivity and has a linear expansion coefficient larger than that of the work holder 9. A spacer 10 made of a large material is provided, and the small-diameter end W1a of the workpiece W1 is accommodated and held inside the spacer 10.

  Accordingly, each work holder 9 holds the work W <b> 1 via the spacer 10, revolves around the corresponding rotation shaft 7 as a center of rotation, and revolves around the turntable 6. Thereby, the workpiece | work rotation means 5 is comprised so that the workpiece | work W1 may perform a big revolution and a small revolution, and may contact uniformly and uniformly with respect to the radiation of Ti ion by acetylene gas and vacuum arc discharge.

  The spacer 10 has an outer diameter that can be loosely inserted into the recess 9a of the work holder 9, and an inner diameter that allows the one end W1a of the work W1 to be loosely inserted inside itself. Therefore, in the state where the assembly of the rotary shaft 7, the work holder table 8 and the work holder 9 is stood outside the chamber 1, the spacer 10 is incorporated in each work holder 9, and the work W1 is further inserted. And is assembled to the turntable 6 while ensuring conduction.

  The concave portion 9a has a thermal expansion in the spacer 10 so that the thermal expansion in the thickness direction of the spacer 10 can fill the gap with the concave portion 9a and the gap with the one end W1a of the workpiece W1 by heating during film formation. It is formed in such a size as to hold a space where a certain thickness dimension that can be generated can be secured.

  As a result, even if the spacer 10 is loosely inserted into the recess 9a of the work holder 9 and the work W1 is loosely inserted inside the spacer 10, the spacer 10 is thermally expanded during film formation and the work W1, the spacer 10, and the work holder 9, the electrical conductivity between the workpiece W1 and the workpiece holder 9 is improved, and the voltage applied to the workpiece holder 9 is reliably transmitted to the workpiece W1 via the spacer 10.

  As shown in FIG. 3, the spacer 10 has a slit 10a on one side. Since the spacer 10 has a cylindrical shape and the circumferential length is large, the slit 10a has a large change in the circumferential length due to thermal expansion. It is provided as a means to avoid this.

  In addition, the slit 10a may be provided obliquely with respect to the generatrix on the cylindrical surface, or may be provided so as to be a bent line. Further, the inner surface and the outer surface of the spacer 10 are not cylindrical surfaces that are in close contact with the concave portion 9a of the work holder 9 or the work W1, but contact along the generatrix direction like splines at least at three locations in the circumferential direction. May be provided to be performed.

  Next, functions of the film forming apparatus 100 configured as described above will be described.

  As shown in FIG. 1, a door (not shown) of the chamber 1 is opened, a spacer 10 is inserted into each work holder 9 of the work rotating means 5, a work W1 is inserted inside the spacer 10, and the door of the chamber 1 is opened. Close the door.

  Next, the work rotating means 5 is activated to give each work W1 revolutions of large and small directions, and after the chamber 1 is evacuated, acetylene gas heated to, for example, 400 ° C. is supplied into the chamber 1.

  Next, with the titanium substrate 4 as an anode, for example, a current of 100 amperes is passed and a voltage is generated, and a voltage of −500 V, for example, is applied to the workpiece W1. Thereby, the film forming apparatus 100 exhibits a function of performing DLC coating by arc ion plating-chemical vapor deposition method, so-called AIP-CVD method, on each workpiece W1.

  FIG. 4 is a schematic diagram showing that the DLC coating is performed on the workpiece W1 by the arc ion plating-chemical vapor deposition method in the chamber 1 at a molecular level.

  When the chamber 1 is heated to a high temperature and a high voltage is applied between the titanium substrate 4 and the workpiece W1, a vacuum arc discharge is generated from the surface of the titanium substrate 4, and Ti ions are emitted from the surface of the titanium substrate 4 to be cathode. Is directed to the surface of the workpiece W1, facing the workpiece W1, the acetylene gas is separated into C2 + ions and H2 + ions due to the presence of the Ti ions, and the C2 + ions are attracted to the surface of the workpiece W1 which is the cathode, and the DLC film. As a film formation.

  This DLC (Diamond Like Carbon) film has a structure that combines diamond bond and graphite bond, and has high hardness, high wear resistance, low friction, low attack resistance, seizure resistance, high insulation, and infrared transmission.・ Excellent features such as high gas barrier properties and biocompatibility.

  Each workpiece W1 is subjected to a complicated centrifugal force due to the small and large revolutions during the formation of the DLC film. For this reason, if there is a gap between the workpiece W1 and the spacer 10, rattling will occur.

  However, in this embodiment, as shown in FIG. 5, the spacer 10 is thermally expanded during film formation, so that the workpiece W1, the spacer 10, and the workpiece holder 9 are integrated, and the workpiece W1, the workpiece holder 9, The voltage applied to the work holder 9 is reliably transmitted to the work W1 through the spacer 10. For this reason, the abnormal discharge between a workpiece | work and a workpiece holder can be suppressed, and a uniform film | membrane can be formed.

  The linear expansion coefficient of stainless steel is ˜12 × 10 −6 / ° C., and the linear expansion coefficient of copper-based alloy is ˜25 × 10 −6 / ° C. Therefore, when the material of the work holder 9 and the work W1 is stainless steel, the spacer 10 can be made of a copper alloy, an aluminum alloy, or the like, and may be plated with chromium to have wear resistance.

  If the gap between the spacer 10 and the workpiece W1 at room temperature (25 ° C.) is 0.05 mm, for example, the spacer 10 is thermally expanded more than the workpiece holder 9 and the workpiece W1 during film formation (˜400 ° C.), and the spacer The gap between the workpiece 10 and the work W1 is zero.

  As described above, the work holder 9 according to the present embodiment includes the spacer 10 that can be fitted to both the concave portion 9a and the workpiece W1 by a slug in the gap between the concave portion 9a and the workpiece W1. The film thermally expands in the diametrical direction in the film, and a dip is fitted into both the recess 9a and the work W1.

  That is, the spacer 10 increases the inner and outer diameters by thermal expansion in the thickness direction during film formation, but when the outer surface comes into contact with the recess 9a, the inner diameter is reduced and comes into contact with the work W1. Thereby, the work W1, the spacer 10, and the work holder 9 are in close contact with each other, the conductivity between the work W1 and the work holder 9 is improved, and the voltage applied to the work holder 9 is applied to the work W1 via the spacer 10. It is transmitted reliably and a more uniform film can be formed as compared to the conventional case. In the case of performing a large amount of processing, the work W1 can be easily inserted into the spacer 10 and the work W1 can be taken out without the spacer 10 being removed after the film formation.

  In addition, since the work holder 9 according to the present embodiment includes the spacer 10 having the slit 10a, the work holder 9 is reduced in diameter by pressing the outer peripheral surface of the spacer 10 with a pressing tool such as pliers. Can be inserted into the recess 9a. Thereby, the outer diameter of the spacer 10 can be set to a size such that there is no gap with respect to the recess 9 a of the work holder 9.

  In the spacer 10, thermal expansion in the circumferential direction during film formation appears as deformation that narrows the slit 10 a, and the presence of the slit 10 a can avoid an abnormal increase in circumferential stress. Further, in the work holder 9 according to the present embodiment, since the spacer 10 has the slit 10a, the inner diameter of the spacer 10 is set to a size that makes a squeeze relative to the diameter of the one end W1a of the work W1, and the spacer 10 is It can also be fitted into one end of the one end W1a of the work W1 and inserted into the recess 9a of the work holder 9.

  In this case, the thermal expansion of the spacer 10 during film formation is performed exclusively in the direction of expanding the outer diameter. For this reason, since the outer diameter of the spacer 10 can be made sufficiently smaller than the inner diameter of the recess 9a of the work holder 9, the work W1 with the spacer fitted thereon can be easily inserted into the recess 9a of the work holder 9. The spacer 10 can be reused when it is taken out after film formation and a spacer is required in another similar process.

  In addition, since the film forming apparatus 100 according to the present embodiment uses the work holder 9 described above, the spacer 10 is thermally expanded during film formation, and the work W1, the spacer 10, and the work holder 9 are in strong contact with each other. Since the conductivity between the workpiece W1 and the workpiece holder 9 is improved, the abnormal discharge between the workpiece W1 and the workpiece holder 9 that has occurred in the past can be suppressed, and more uniform coating than in the past. Can be formed. In addition, when performing a large amount of processing, the work W1 can be easily inserted into the spacer 10 and the work W1 can be taken out without the spacer being removed after film formation.

  6 is a copy of a photograph showing the DLC film formed on the workpiece W1 using the film forming apparatus shown in FIG. 1 provided with the work holder 9 provided with the spacer 10 shown in FIG. As apparent from the copy of this photograph, no DLC film is formed because no discharge traces are formed.

Comparative example

  FIG. 7 is a longitudinal sectional view showing a state where the work W2 is held by the conventional work holder 12 and film formation is performed. Since the conventional work holder 12 has no spacer, the diameter of the recess 12a is reduced. However, a gap is formed between the recess 12a and the one end W2a having a small diameter of the work W2.

  For this reason, the workpiece W2 receives a complicated centrifugal force due to the revolving of the small turn and the large turn to cause rattling, and the contact area that holds the conductivity between the work W2 and the work holder 12 may be instantaneously separated. Due to this, a large potential difference is induced between the open end of the concave portion of the work holder 12 and the lower end of the large-diameter portion of the work W2, and an abnormal discharge 13 is generated, and the DLC formed in the large-diameter portion of the work W2. As will be described later, the film produces a discharge trace near the lower end of the large-diameter portion of the workpiece W2, and the film quality becomes non-uniform around the discharge trace.

  FIG. 8 is a copy of a photograph showing a DLC film formed on the workpiece W2 using a film forming apparatus equivalent to the film forming apparatus shown in FIG. 1 provided with the conventional work holder 12 shown in FIG. As is apparent from a copy of this photograph, the surface texture is such that the discharge marks are generated and the DLC film is formed and then peeled off.

[Other Embodiments]
The present invention is not limited to the above-described embodiments, and the technical scope of the claims includes various design changes within the scope not departing from the gist of the invention. In the said embodiment, although the example which comprised the workpiece | work rotation means 5 was shown so that the workpiece holder 9 might perform a big revolution and a small revolution, the workpiece | work rotation means 5 was changed so that the workpiece holder 9 might rotate and revolve. It may be configured.

  A work holder support shaft that rotates and rotates on each work holder table 8 may be provided, and a work holder 9 that is connected and fixed so as to be positioned on the extended axis above the work holder support shaft may be provided.

  The work holder 9 and the film forming apparatus using the work holder 9 according to the present invention are not limited to DLC as tribo coating, but are also applied to TiC, TiCN, CrC, Al2O3, CrC, SiC, and other CVD. The present invention is also applicable to arc, PVD, gas flame spraying, and the like.

  The work holder and the film forming apparatus using the work holder according to the present invention are capable of forming a uniform film by preventing the work from being instantaneously separated from the work holder during film formation and suppressing abnormal discharge. It is useful for a film forming apparatus that uses a work holder that houses and holds one end of a work, heats the work to a required temperature, and applies a voltage to the work to form a film.

DESCRIPTION OF SYMBOLS 1 ... Chamber, 5 ... Work rotating means, 6 ... Rotary table, 9 ... Work holder, 9a ... Recessed part, 10 ... Spacer, 10a ... Slit, 100 ... Film formation apparatus, W1 ... Workpiece

Claims (3)

One end of the workpiece is provided to rotate at least one of rotation and revolution, and holds and holds one end of the workpiece in the recess, applies a voltage to the workpiece, contacts the source gas, and heats to a required temperature. In the work holder that forms a film on the part other than
The recess is formed in a size having a predetermined gap around one end of the workpiece, and includes a spacer that fills the gap.
The said spacer is comprised including the material which has electroconductivity and whose linear expansion coefficient is larger than the linear expansion coefficient of the said work holder, The work holder characterized by the above-mentioned.   The work holder according to claim 1, wherein the spacer includes a slit on one side along a generatrix direction. A work holder provided in the chamber to rotate at least one of rotation and revolution, and having a recess and accommodating and holding one end of the work in the recess. In a film forming apparatus for forming a film by applying a voltage to
The said work holder is provided with the work holder in any one of Claim 1 or 2, The film forming apparatus characterized by the above-mentioned.