JP2007059305A - Plasma processing method and device or conductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma processing method and a device capable of removing a covering of the whole processing objects at a high speed when processing a plurality of processing objects adjacently contacting with one place or more in a batch system; and to provide a conductor for easily securing electric continuity with a desired metallic member, for example, caulking with a crimp terminal by removing the covering in a short time by plasma. <P>SOLUTION: An insulator chamber 3 is arranged between an upper electrode 1 and a lower electrode 2, and a gas flow passage 4 is formed on its inside. While vibrating the processing objects 10 by a vibrating unit 13, processing gas is supplied inside from a processing gas supply device 5, and the plasma 12 is generated by supplying an AC electric field between the electrodes from a high frequency power source 9. The covering of the whole processing objects can be removed at a high speed by positioning the plurality of processing objects 10 adjacently contacting with one place or more by separating from between the electrodes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention uses plasma under a pressure close to atmospheric pressure, and each surface to be processed is applied to a conductor, a wiring component, an electronic component, a component terminal, a printed circuit board, a sheet substrate, a film substrate, particularly a plurality of objects to be processed. Plasma treatment method and apparatus for surface treatment at high speed, and the surface treatment ensures the conduction with the desired metal member without the need for metal plating such as solder on the copper wire from which the coating has been removed. It relates to a conductive wire.

  A plasma processing method and apparatus using plasma generated under a pressure close to atmospheric pressure (hereinafter referred to as “atmospheric pressure plasma”) is used for, for example, conducting wires and wiring components for reasons such as apparatus cost reduction, space saving, and energy saving. In some of the etching, film formation and surface treatment processes in the manufacturing process of electronic parts, component terminals, printed boards, sheet substrates, film substrates, etc., conversion from plasma using a decompression device is attempted.

  A plasma processing method and apparatus as a conventional example will be described with reference to FIGS.

  FIG. 10 shows a front view of the plasma processing apparatus, and FIG. 11 shows a cross-sectional view taken along line GG of the front view. In FIG. 11, an upper electrode 1 and a lower electrode 2 are provided, and an insulator chamber 3 is provided between both electrodes. Further, a gas flow path 4 is formed inside the insulator chamber 3, and gas is supplied to the inside through the gas supply port 7 in the processing gas supply device 5 and the metal container 6, and passes through the gas flow path 4. The high-frequency power is supplied to the upper electrode 1 from the high-frequency power source 9 and the AC electric field is supplied between the upper electrode 1 and the lower electrode 2 while exhausting the processing gas from the gas outlet 8 into the atmosphere. . In addition, the object to be processed 10 can be inserted from the gas ejection port 8 and placed on an arbitrary place in the insulator chamber 3. The lower electrode 2 and the metal container 6 are basically set to ground potential, and the upper electrode 1 and the metal container 6 are insulated by an insulating block 11.

As an example of plasma processing by this apparatus, an object to be processed 10 is placed in an insulator chamber 3, and He = 750 sccm, O ₂ = 40 sccm, CF ₄ = 13 sccm are supplied as processing gases from the processing gas supply device 5, By supplying electric power of 100 W from the high frequency power supply 9, plasma 12 can be generated between the upper electrode 1 and the lower electrode 2, and the workpiece 10 can be plasma processed.

  Further, by the plasma processing method described above, for example, the object to be processed 10 as a coated copper wire in which an imide organic film is applied to the surface of a copper wire can be plasma-treated. At this time, the coated copper wire is not only inserted into the insulator chamber 3 as a single wire and subjected to plasma treatment, but also inserted into the insulator chamber 3 in the state of a base wire (a state where a plurality of wires are bundled using an adhesive or the like). Plasma processing can also be performed as so-called batch processing.

10 to 11 are based on the plasma processing method and apparatus described in Patent Document 1 or unpublished Japanese Patent Application No. 2003-363081, and generate plasma between a pair of electrodes provided with a solid dielectric. In this method, the object to be processed is plasma-treated by placing the object to be processed in a space formed between the electrodes. This method is generally called a direct method, and the object to be processed is directly exposed to high-density plasma, so that high-speed plasma processing is possible.
JP 2004-363152 A

  The results of plasma processing of an object to be processed by the conventional plasma processing method and apparatus are shown below. The object to be treated is a coated copper wire in which polyimide amide is coated on the surface of the copper wire as an imide-based organic film with a thickness of 15 μm, and 40 wires are bundled with an adhesive. Was used.

  In addition, the evaluation regarding the presence or absence of the coating removal of the coated copper wire was carried out by embedding the ground wire after the plasma treatment in an epoxy resin, rotating and polishing with emery paper, etc., and then observing the cross section of the copper wire by SEM .

  The plasma processing result in the conventional example is shown in FIG. In the figure, the horizontal axis represents the plasma treatment time, and the vertical axis represents the number of copper wires that have been coated. As described above, the removal of the coating progressed at a high speed and with a high linearity until the plasma treatment time was about 90 seconds, and about 32 out of 40 pieces could be removed. In addition, the 40 coatings could be removed by performing the plasma treatment for 390 s.

  However, the coating removal speed is extremely reduced after 90 seconds elapses, and it is difficult to remove the coating of the processing object located in the center, and as a result, 390 s is very long to remove all 40 coatings. There was a problem of taking time.

  In addition, when the conductors from which the coating has been removed using the plasma processing method and apparatus in the conventional example are bundled again and joined to a desired metal member without performing metal plating such as solder, conduction with the metal member cannot be secured. There was a problem (high resistivity).

  In view of the above-described conventional problems, the present invention provides a plasma processing method and apparatus that can remove all coatings of a workpiece at high speed in batch processing of a plurality of workpieces that are adjacent and in contact at one or more locations. Moreover, it aims at providing the conducting wire which becomes easy to ensure conduction | electrical_connection with a desired metal member by the surface treatment.

In the plasma processing method according to the first invention of the present application, a solid dielectric is provided on at least one of a pair of electrodes, and high-frequency power is supplied while supplying a processing gas between the electrodes. A method of generating plasma, irradiating an object to be processed with a gas in a plasma state, and performing plasma processing on a plurality of objects to be processed that are in contact with at least one place,
A surface to be processed is irradiated with a gas in a plasma state without placing an object to be processed in a space formed between a pair of electrodes.

  With such a configuration, it is possible to realize that it is possible to remove the coating of all the objects to be processed at high speed in the batch processing of a plurality of objects to be processed that are adjacent and in contact with one or more places.

In the plasma processing method of the second invention of the present application, a solid dielectric is provided on at least one of a pair of electrodes, and high-frequency power is supplied while supplying a processing gas between the electrodes. A method of generating plasma, irradiating an object to be processed with a gas in a plasma state, and performing plasma processing on a plurality of objects to be processed that are in contact with at least one place,
A surface to be processed is irradiated with a gas in a plasma state from at least two directions without placing an object to be processed in a space formed between a pair of electrodes.

  With such a configuration, it is possible to realize that it is possible to remove the coating of all the objects to be processed at high speed in the batch processing of a plurality of objects to be processed that are adjacent and in contact with one or more places.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the object to be processed is in the form of a thread or a rod.

  In addition, it is preferable that a plurality of objects to be processed are stacked, bundled, or relied on.

  Preferably, the object to be processed is a metal whose surface is partially and entirely covered with an organic film, and more preferably, the organic film is a thermosetting resin.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the object to be processed is in the form of a film, a sheet or a plate.

  Further, it is preferable that a plurality of objects to be processed are stacked.

  Also preferably, the object to be treated is a metal whose surface is partially and entirely covered with an organic film.

  In the plasma processing method of the first invention of the present application, it is preferable to irradiate a gas in a plasma state from the line direction of the workpiece.

  In the plasma processing method of the second invention of the present application, preferably, at least one direction is irradiated with a gas in a plasma state from a line direction of the object to be processed, and at least one direction is perpendicular to the line direction of the object to be processed. It is desirable to irradiate a gas in a plasma state from a certain direction.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the position of the object to be processed is preferably moved with respect to the average flow velocity direction of the gas to be supplied.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable to perform processing while vibrating or rotating the surface to be processed.

  More preferably, the vibration frequency is preferably 0.1 Hz to 500 kHz.

  More preferably, the rotational frequency is from 0.1 Hz to 500 kHz.

  In the plasma processing methods of the first and second inventions of the present application, it is desirable that the flow rate of the supplied gas is preferably increased during the plasma processing or between the plasma processing and more preferably, It is desirable to reduce the contact area between adjacent workpieces by intermittently increasing the flow rate of the supplied gas.

  More preferably, the gas flow rate is desirably increased by a transient gas flow that flows at the moment when the gas supply is temporarily interrupted and the gas supply is resumed.

  More preferably, it is desirable to shut off and restart the gas supply via a gas stop valve.

  In the plasma processing methods of the first and second inventions of the present application, preferably, the object to be processed is surrounded by at least two walls, and the two walls are opposed to each other.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the distance between the electrodes is 10 mm or less.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the distance between the electrodes is 4 mm or less.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the position where the end surface of the object to be processed is placed is separated by 0.5 mm or more from the space formed between the electrodes.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the position where the end face of the workpiece is placed is 10 mm or less from the space formed between the electrodes.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the processing gas contains an inert gas at a ratio of 50% or more.

  In the plasma processing methods of the first and second inventions of the present application, it is preferable that the processing gas contains an inert gas at a ratio of 99.9% or less.

In the plasma processing methods of the first and second inventions of the present application, preferably, a first step of performing plasma processing using a gas containing an inert gas and O ₂ gas, and a gas containing an inert gas and a reducing gas It is desirable to carry out the second step of performing plasma treatment using, and more preferably, the organic film on the surface of the workpiece is removed in the first step, and the metal element on the surface of the workpiece in the second step Is preferably reduced. More preferably, the reducing gas is any one of H ₂ , NH ₃ , N ₂ , and CO gas.

In the plasma processing methods of the first and second inventions of the present application, it is preferable that the processing gas includes O ₂ gas and at least one of N ₂ and F element-containing gas.

Also preferably, F element-containing gas is _{F 2, CHF 3, HF,} CF 4, C 2 F 4, C 2 F 6, C 3 F 6, C 4 F 6, C 3 F 8, C 4 F 8 , C ₅ F ₈ , NF ₃ and SF ₆ gas are desirable.

  The conducting wire according to the first invention of the present application provides plasma at a pressure near atmospheric pressure by providing a solid dielectric on at least one of a pair of electrodes and supplying high-frequency power while supplying a processing gas between the electrodes. Generate and irradiate the object to be processed with a gas in a plasma state, and place the object to be processed in a space formed by a plurality of and at least one place between a pair of electrodes, Plasma treatment is performed by irradiating the surface to be treated with a gas in a plasma state, and a plurality of objects to be treated are surrounded by metal members, and mechanical pressure is applied to bring the objects to be treated into contact with the metal members. According to the process, the object to be processed and the metal member are made conductive.

  With such a configuration, it is possible to provide a conductive wire that facilitates securing conduction with a desired metal member.

  Preferably, the step of applying mechanical pressure is a step of crimping.

  Preferably, the metal member is a crimp terminal.

The plasma processing apparatus according to the first invention of the present application includes a solid dielectric provided at least between a pair of electrodes, a high-frequency power source connectable to the electrodes, and a gas supply device capable of supplying a processing gas between the electrodes. A plasma processing apparatus capable of supplying a processing gas to a processing surface of an object to be processed via a gas flow path provided in a space formed by
It is characterized by comprising a wall made of at least two opposing insulators connected to the space formed between the electrodes.

  With such a configuration, it is possible to realize that it is possible to remove the coating of all the objects to be processed at high speed in the batch processing of a plurality of objects to be processed that are adjacent and in contact with one or more places.

The plasma processing apparatus of the second invention of the present application is provided with a solid dielectric provided at least between a pair of electrodes, a high-frequency power source connectable to the electrodes, and a gas supply device capable of supplying a processing gas between the electrodes. A plasma processing apparatus capable of supplying a processing gas to the entire processing surface of an object to be processed via a gas flow path provided in a space formed by
It is characterized in that it is provided with a wall made of at least two opposing insulators connected to a space formed between the electrodes, and further provided with at least two systems of the gas flow paths.

  With such a configuration, it is possible to realize that it is possible to remove the coating of all the objects to be processed at high speed in the batch processing of a plurality of objects to be processed that are adjacent and in contact with one or more places.

  In the plasma processing apparatus according to the first and second inventions of the present application, it is preferable to provide a moving mechanism that can change the position of the object to be processed relative to the electrode.

  Preferably, the moving mechanism is preferably a mechanism that can transmit vibration or a rotation.

  In the plasma processing apparatuses according to the first and second inventions of the present application, it is preferable to provide a breaking mechanism that can reduce the contact area between the objects to be processed adjacent to each other.

  As described above, according to the plasma processing method and apparatus of the present invention, in batch processing of a plurality of workpieces that are adjacent and in contact with one or more locations, by supplying high-density plasma while suppressing heat conduction, To provide a plasma processing method and apparatus capable of removing all coatings of an object to be processed at high speed, and to remove a coating in a short time by plasma, for example, a desired metal member such as caulking with a crimp terminal. It is possible to provide a conductive wire that facilitates ensuring electrical continuity.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

  FIG. 1 is a cross-sectional view showing the configuration of the plasma processing apparatus in the first embodiment of the present invention. In FIG. 1, an upper electrode 1 and a lower electrode 2 are provided, and an insulator chamber 3 is provided between both electrodes. Further, a gas flow path 4 is formed inside the insulator chamber 3, and gas is supplied to the inside through the gas supply port 7 in the processing gas supply device 5 and the metal container 6, and passes through the gas flow path 4. The high-frequency power is supplied to the upper electrode 1 from the high-frequency power source 9 and the AC electric field is supplied between the upper electrode 1 and the lower electrode 2 while exhausting the processing gas from the gas outlet 8 into the atmosphere. . In addition, the object to be processed 10 can be inserted from the gas ejection port 8 and placed on an arbitrary place in the insulator chamber 3. The lower electrode 2 and the metal container 6 are basically set to ground potential, and the upper electrode 1 and the metal container 6 are insulated by an insulating block 11. Plasma 12 can be generated between the upper electrode 1 and the lower electrode 2 using such a plasma processing apparatus.

  Here, the vibration unit 13 can move the workpiece to reciprocate in the Z direction.

  In the embodiment of the present invention, an object to be processed as shown in FIGS. 2 to 3 is used. FIG. 2 shows an enlarged schematic view of a cross section of the object to be processed, and FIG. 3 shows a schematic external view of the object to be processed. As shown in FIG. 2, the object to be treated 10 covers an imide organic film 15 with a thickness M = 15 μm around a copper wire 14 having a diameter L = 0.09 mm. In addition, as shown in FIG. 3, a ground wire in which 40 coated wires were bundled using an adhesive as shown in FIG. Here, as shown in FIG. 3, the length direction N of the copper wire is referred to as a line direction, and the direction O parallel to the cross section of the ground wire (or the cross section of each copper wire) is referred to as the radial direction.

As an example of plasma processing by this apparatus, the processing object 10 is inserted into the insulator chamber 3 and the processing object 10 is moved by the vibration unit 13, while He = 750 sccm, O ₂ = 40 sccm, CF ₄ as processing gases. = 13 sccm and 100 W from the high-frequency power source 9 to generate plasma 12 between the upper electrode 1 and the lower electrode 2, and the object to be processed 10 was plasma-treated. The vibration conditions of the vibration unit 13 were an amplitude of 1.5 mm and a frequency of 5 Hz, and the distance P between the electrodes was 2 mm as shown in the enlarged cross-sectional view in the vicinity of the electrodes in FIG. At this time, the end surface of the workpiece 10 is placed at a position that does not reach between both electrodes, that is, at a position 1 mm away from the broken line AA that is the end surface of the space between both electrodes, and the upper electrode 1 The plasma 12 generated in the space formed by the lower electrode 2 is not directly exposed.

  As a result of subjecting the workpiece 10 to plasma processing using the plasma processing method and apparatus described above, it was possible to remove all 40 coated copper wires by 90 s plasma processing. At this time, the coating removal length in the line direction was 5 mm.

  FIG. 5 shows an SEM image of the cross section observed after removing the coating, dipping for 3 s in a Sn—Ag—Cu lead-free solder bath at 250 ° C., plating the solder, embedding in an epoxy resin, and observing the cross section. As is clear from FIG. 5, lead-free solder 16 was plated around all the copper wires 14, and an alloy layer was formed at the interface of the copper wires 14. This indicates that the imide-based organic film is removed without residue in all 40 films.

  In this way, it was evaluated whether or not the imide organic film 15 was removed from the coated copper wire by observing the cross section with an SEM.

  Next, with the above plasma processing method and apparatus, the coating on both ends of the workpiece 10 is removed to expose the copper wire, and crimp terminals are crimped on both ends to confirm the presence or absence of conduction. Was confirmed.

  As described above, the reason why the coating could be removed in a short time is considered to be that the organic film alteration due to heat reduces the organic film removal rate due to chemical reaction. In general, plasma under atmospheric pressure is difficult to obtain under reduced pressure, and it is possible to generate very high density plasma. However, on the other hand, since the number of collisions between particles increases, it is known that as the density increases, a thermal equilibrium state is approached and the gas temperature becomes very high. Therefore, as in the conventional example, when high-density plasma is directly exposed to the object to be processed, the heat conduction is conducted faster than the chemical reaction by the plasma active species penetrates into the ground wire, and the organic film covered with the copper wire. Is considered to be thermoset. As a result, it can be expected that the removal rate of the organic film by the chemical reaction is reduced and the removal rate is extremely reduced at the center of the object to be processed.

  On the other hand, in the first embodiment, it can be expected that the high-temperature and high-density plasma generated between the two electrodes becomes the low-temperature and high-density plasma before reaching the object to be processed at a distant position. If the distance between the electrodes is not so far, it is considered that the gas temperature decreases but the plasma density does not decrease so much because the He radical lifetime is long, and it can reach the object to be processed as a low-temperature and high-density plasma.

  The following three things are also considered as reasons. First, the penetration of plasma active species is radial in the conventional example, but is linear in the first embodiment, and the penetration rate of plasma active species into the interior of the ground wire is increased. Secondly, by vibrating the workpiece, it was possible to prevent the plasma active species from irradiating only a specific surface of the workpiece, and to suppress the accumulation of heat at a specific location. Third, by vibrating the workpiece, the workpiece can be prevented from coming into contact with the wall surface of the insulator chamber for a long time, and heat conduction from the wall surface to the workpiece can be suppressed.

  For these reasons, it is considered that the deterioration of the organic film due to heat can be suppressed, and the coating removal rate has been greatly improved.

  Next, the following can be considered as a reason why the conduction can be ensured.

  In the conventional example, an oxide film thicker than the natural oxide film is formed on the copper wire at the outermost periphery of the base wire due to heat supplied from the plasma, etc., and the adjacent copper wires or the copper wires are crimped together. It is thought that the contact resistance between terminals increased. On the other hand, in the first embodiment, it was considered that the conduction was ensured because the plasma treatment could be performed without oxidizing the surface even in the outermost copper wire.

(Embodiment 2)
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 6 is a cross-sectional view of a plasma processing apparatus according to the second embodiment of the present invention, and the basic configuration is the same as that of the first embodiment. However, the configuration is such that the workpiece 10 can be irradiated with plasma from two directions (not shown). FIG. 7 shows an upper cross-sectional view taken along the line CC in FIG. In FIG. 7, upper electrodes 1-a, 1-b and lower electrodes 2-a, 2-b (both not shown, but are placed on portions corresponding to broken lines D, E) are provided between the two electrodes. Is provided with an insulator chamber 3. Further, a gas flow path 4 is formed inside the insulator chamber 3, and gas is supplied to the inside through the gas supply ports 7 in the processing gas supply devices 5-a and 5-b and the metal container 6, High-frequency power is supplied to the upper electrodes 1-a and 1-b from a high-frequency power source 9 (not shown) while exhausting the processing gas from the gas outlet 8 through the gas flow path 4 to the atmosphere. -A, 1-b and the lower electrodes 2-a, 2-b can be supplied with an alternating electric field. In addition, the object to be processed 10 can be inserted from the gas ejection port 8 and placed on an arbitrary place in the insulator chamber 3. The lower electrodes 2-a and 2-b and the metal container 6 are basically at ground potential, and the upper electrodes 1-a and 1-b and the metal container 6 are insulated by an insulating block 11 (not shown). . Using such a plasma processing apparatus, plasmas 12-a and 12-b can be generated between the upper electrodes 1-a and 1-b and the lower electrodes 2-a and 2-b.

  Here, the vibration unit 13 can move the workpiece to reciprocate in the Y direction.

As an example of plasma processing by this apparatus, the processing object 10 is inserted into the insulator chamber 3, and the processing object 10 is moved by the vibration unit 13, while He = 750 sccm, O ₂ from the processing gas supply device 5-a. = 40 sccm, CF ₄ = 13 sccm is supplied, He = 1000 sccm, O ₂ = 40 sccm, CF ₄ = 13 sccm is supplied from the processing gas supply device 5-b, and the region 1-a formed between the two electrodes and between the two electrodes By supplying 100 W of power from the high frequency power supply 9 to the region 1-b to be formed, plasmas 12-a and 12-b were generated, and the workpiece 10 was plasma-treated. The vibration conditions of the vibration unit 13 are an amplitude of 1.5 mm (set value) and a vibration frequency of 5 Hz. As in the first embodiment, the distance between the upper electrode 1-a and the lower electrode 2-a, the upper electrode 1- The distance between b and the lower electrode 2-b was 2 mm. At this time, the end face of the workpiece 10 does not reach between the two electrodes, that is, 1 mm away from the end face FF of the D formed between the two electrodes and the end face GG of the distance E formed between the two electrodes. It was placed so that it was not directly exposed to the plasma 12-a, 12-b generated in the space formed by the upper electrodes 1-a, 1-b and the lower electrodes 2-a, 2-b.

  As a result of the plasma treatment of the workpiece 10 by the plasma treatment method and apparatus described above, it was possible to remove the coating of all 40 coated copper wires by the plasma treatment for 60 s. At this time, the coating removal length in the line direction was 10 mm.

  Next, with the above plasma processing method and apparatus, the coating on both ends of the workpiece 10 is removed to expose the copper wire, and crimp terminals are crimped on both ends to confirm the presence or absence of conduction. Was confirmed.

  As described above, the reason why the coating could be removed in a short time is considered to be that the organic film alteration due to heat reduces the organic film removal rate due to chemical reaction. In general, plasma under atmospheric pressure is difficult to obtain under reduced pressure, and it is possible to generate very high density plasma. However, on the other hand, since the number of collisions between particles increases, it is known that as the density increases, a thermal equilibrium state is approached and the gas temperature becomes very high. Therefore, as in the conventional example, when high-density plasma is directly exposed to the object to be processed, the heat conduction is conducted faster than the chemical reaction by the plasma active species penetrates into the ground wire, and the organic film covered with the copper wire. Is considered to be thermoset. As a result, it can be expected that the removal rate of the organic film by the chemical reaction is reduced and the removal rate is extremely reduced at the center of the object to be processed.

  On the other hand, in the second embodiment, it can be expected that the high-temperature and high-density plasma generated between the two electrodes becomes the low-temperature and high-density plasma before reaching the object to be processed at a distant position. If the distance between the electrodes is not so far, it is considered that the gas temperature decreases but the plasma density does not decrease so much because the He radical lifetime is long, and it can reach the object to be processed as a low-temperature and high-density plasma.

  The following three things are also considered as reasons. First, the penetration of plasma active species is radial in the conventional example, but is linear in the first embodiment, and the penetration rate of plasma active species into the interior of the ground wire is increased. Secondly, by vibrating the workpiece, it was possible to prevent the plasma active species from irradiating only a specific surface of the workpiece, and to suppress the accumulation of heat at a specific location. Third, by vibrating the workpiece, the workpiece can be prevented from coming into contact with the wall surface of the insulator chamber for a long time, and heat conduction from the wall surface to the workpiece can be suppressed.

  For these reasons, it is considered that the deterioration of the organic film due to heat can be suppressed, and the coating removal rate has been greatly improved.

  In addition, it is considered that more plasma active species can be supplied to the object to be processed by irradiating plasma from two directions, and the coating removal time can be further shortened.

  Next, the following can be considered as a reason why the conduction can be ensured.

  In the conventional example, an oxide film thicker than the natural oxide film is formed on the copper wire at the outermost periphery of the base wire due to heat supplied from the plasma, etc., and the adjacent copper wires or the copper wires are crimped together. It is thought that the contact resistance between terminals increased. On the other hand, in the second embodiment, it was considered that the conduction was ensured because the plasma treatment could be performed without oxidizing the surface even in the outermost copper wire.

(Embodiment 3)
Hereinafter, a third embodiment of the present invention will be described with reference to FIGS.

  The configuration of the plasma processing apparatus is the same as that of the first embodiment.

As an example of plasma processing by this apparatus, the processing object 10 is inserted into the insulator chamber 3, and the processing object 10 is moved by the vibration unit 13, while He = 750 sccm, O ₂ = 40 sccm, CF ₄ as processing gases. = 13 sccm and 100 W from the high-frequency power source 9 to generate plasma 12 between the upper electrode 1 and the lower electrode 2, and the object to be processed 10 was plasma-treated. The vibration conditions of the vibration unit 13 were an amplitude of 1.5 mm and a frequency of 5 Hz, and the distance P between the electrodes was 2 mm as shown in the enlarged cross-sectional view in the vicinity of the electrodes in FIG. At this time, the end surface of the workpiece 10 is placed at a position that does not reach between both electrodes, that is, at a position 1 mm away from the broken line AA that is the end surface of the space between the two electrodes. The plasma 12 generated in the space formed by the lower electrode 2 is not directly exposed.

  After performing plasma processing for 25 s under such plasma processing conditions, supply of the processing gas is stopped by closing the gas stop valve (not shown) for 5 s by closing the gas stop valve (not shown) and opening the gas stop valve again. A 30s unit process of restarting was performed twice, and then a 30s plasma process was performed again.

  As a result of subjecting the workpiece 10 to plasma processing using the plasma processing method and apparatus described above, it was possible to remove all 40 coated copper wires by 90 s plasma processing. At this time, the coating removal length in the line direction was 8 mm.

  Next, with the above plasma processing method and apparatus, the coating on both ends of the workpiece 10 is removed to expose the copper wire, and crimp terminals are crimped on both ends to confirm the presence or absence of conduction. Was confirmed.

  As described above, the reason why the coating could be removed in a short time is considered to be that the organic film alteration due to heat reduces the organic film removal rate due to chemical reaction. In general, plasma under atmospheric pressure is difficult to obtain under reduced pressure, and it is possible to generate very high density plasma. However, on the other hand, since the number of collisions between particles increases, it is known that as the density increases, a thermal equilibrium state is approached and the gas temperature becomes very high. Therefore, as in the conventional example, when high-density plasma is directly exposed to the object to be processed, the heat conduction is conducted faster than the chemical reaction by the plasma active species penetrates into the ground wire, and the organic film covered with the copper wire. Is considered to be thermoset. As a result, it can be expected that the removal rate of the organic film by the chemical reaction is reduced and the removal rate is extremely reduced at the center of the object to be processed.

  On the other hand, in the third embodiment, it can be expected that the high-temperature and high-density plasma generated between the two electrodes becomes the low-temperature and high-density plasma before reaching the object to be processed at a distant position. If the distance between the electrodes is not so far, it is considered that the gas temperature decreases but the plasma density does not decrease so much because the He radical lifetime is long, and it can reach the object to be processed as a low-temperature and high-density plasma.

  The following three things are also considered as reasons. First, the penetration of plasma active species is radial in the conventional example, but is linear in the first embodiment, and the penetration rate of plasma active species into the interior of the ground wire is increased. Secondly, by vibrating the workpiece, it was possible to prevent the plasma active species from irradiating only a specific surface of the workpiece, and to suppress the accumulation of heat at a specific location. Third, by vibrating the workpiece, the workpiece can be prevented from coming into contact with the wall surface of the insulator chamber for a long time, and heat conduction from the wall surface to the workpiece can be suppressed.

  For these reasons, it is considered that the deterioration of the organic film due to heat can be suppressed, and the coating removal rate has been greatly improved.

  Further, by repeatedly shutting off and restarting the gas supply using the gas stop valve during the plasma processing, an excessive gas flow rate is generated when the gas supply is restarted. It is considered that the removal rate of the coating is further improved by receiving the force from the gas flow and unraveling the object to be processed, which is the base line, so that the plasma active species can easily permeate.

  Next, the following can be considered as a reason why the conduction can be ensured.

  In the conventional example, an oxide film thicker than the natural oxide film is formed on the copper wire at the outermost periphery of the base wire due to heat supplied from the plasma, etc., and the adjacent copper wires or the copper wires are crimped together. It is thought that the contact resistance between terminals increased. On the other hand, in the third embodiment, it is considered that the conduction was ensured because the plasma treatment could be performed without oxidizing the surface of the outermost copper wire.

(Embodiment 4)
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIGS. 4, 8 and 9.

  FIG. 8 is a cross-sectional view of the plasma processing apparatus in the first embodiment of the present invention. 8, the basic configuration of the plasma processing apparatus is the same as that in FIG. 1, and plasma 12 can be generated between the upper electrode 1 and the lower electrode 2. Further, the vibrating unit 13 can move the workpiece to reciprocate in the Z direction.

  In addition, the conveyance unit 17 is connected to the vibration unit 13, and the workpiece 10 is conveyed between the adjacent unraveling unit 18 and the plasma processing apparatus.

  FIG. 9 shows an enlarged cross-sectional view of the inside of the breaking unit 18. By placing the object to be processed 10 on the base 19 and pressing the terminal 20 against the object to be processed 10, the ground wire can be solved. That is, the coated copper wires bonded to each other with the adhesive can be peeled off. After moving the terminal 20 in the X direction, the operation of pressing the terminal 20 against the workpiece 10 again is repeated, so that an arbitrary length with respect to the line direction can be solved. Alternatively, by moving the terminal 20 in the X direction while pressing the terminal 20 against the workpiece 10, an arbitrary length can be solved with respect to the line direction.

As an example of plasma processing by this apparatus, after the tip of the workpiece 10 is unwound by the unraveling unit 18, the workpiece 10 is taken out by the transport unit 17, and the workpiece 10 is inserted into the insulator chamber 3, While moving the object 10 to be processed by the vibration unit 13, He = 750 sccm, O ₂ = 40 sccm, CF ₄ = 13 sccm are supplied as processing gases, and 100 W is supplied from the high frequency power source 9, so that the upper electrode 1 and the lower Plasma 12 was generated between the electrodes 2 and the workpiece 10 was plasma treated. The vibration conditions of the vibration unit 13 were an amplitude of 1.5 mm and a frequency of 5 Hz, and the distance P between the electrodes was 2 mm as shown in the enlarged cross-sectional view in the vicinity of the electrodes in FIG. At this time, the end surface of the workpiece 10 is placed at a position that does not reach between both electrodes, that is, at a position 1 mm away from the broken line AA that is the end surface of the space between both electrodes, and the upper electrode 1 The plasma 12 generated in the space formed by the lower electrode 2 is not directly exposed.

  As a result of the plasma treatment of the workpiece 10 by the plasma treatment method and apparatus described above, it was possible to remove the coating of all 40 coated copper wires by the plasma treatment of 70 s. At this time, the coating removal length in the line direction was 6.5 mm.

  Next, with the above plasma processing method and apparatus, the coating on both ends of the workpiece 10 is removed to expose the copper wire, and crimp terminals are crimped on both ends to confirm the presence or absence of conduction. Was confirmed.

  As described above, the reason why the coating could be removed in a short time is considered to be that the organic film alteration due to heat reduces the organic film removal rate due to chemical reaction. In general, plasma under atmospheric pressure is difficult to obtain under reduced pressure, and it is possible to generate very high density plasma. However, on the other hand, since the number of collisions between particles increases, it is known that as the density increases, a thermal equilibrium state is approached and the gas temperature becomes very high. Therefore, as in the conventional example, when high-density plasma is directly exposed to the object to be processed, the heat conduction is conducted faster than the chemical reaction by the plasma active species penetrates into the ground wire, and the organic film covered with the copper wire. Is considered to be thermoset. As a result, it can be expected that the removal rate of the organic film by the chemical reaction is reduced and the removal rate is extremely reduced at the center of the object to be processed.

  On the other hand, in the fourth embodiment, it can be expected that the high-temperature and high-density plasma generated between the two electrodes becomes the low-temperature and high-density plasma before reaching the object to be processed at a distant position. If the distance between the electrodes is not so far, it is considered that the gas temperature decreases but the plasma density does not decrease so much because the He radical lifetime is long, and it can reach the object to be processed as a low-temperature and high-density plasma.

  The following three things are also considered as reasons. First, the penetration of plasma active species is radial in the conventional example, but is linear in the first embodiment, and the penetration rate of plasma active species into the interior of the ground wire is increased. Secondly, by vibrating the workpiece, it was possible to prevent the plasma active species from irradiating only a specific surface of the workpiece, and to suppress the accumulation of heat at a specific location. Third, by vibrating the workpiece, the workpiece can be prevented from coming into contact with the wall surface of the insulator chamber for a long time, and heat conduction from the wall surface to the workpiece can be suppressed.

  For these reasons, it is considered that the deterioration of the organic film due to heat can be suppressed, and the coating removal rate has been greatly improved.

  Moreover, it is considered that the plasma-activated species can easily permeate and the coating removal rate is improved by removing the coated copper wires using a breaking unit before the plasma treatment.

  Next, the following can be considered as a reason why the conduction can be ensured.

  In the conventional example, an oxide film thicker than the natural oxide film is formed on the copper wire at the outermost periphery of the base wire due to heat supplied from the plasma, etc., and the adjacent copper wires or the copper wires are crimped together. It is thought that the contact resistance between terminals increased. On the other hand, in the fourth embodiment, it was considered that the conduction was ensured because the plasma treatment could be performed without oxidizing the surface even in the outermost copper wire.

  As described above, in the embodiment of the present invention, the imide organic film polyimide amide is exemplified as the organic film, but the organic film is not limited thereto. In particular, if it is a thermosetting resin, it has a special effect, such as an ester organic film, an ester imide organic film, a urethane organic film, an epoxy organic film, an imide organic film, and an amide organic film. An effect equivalent to that of the present invention can be obtained with an organic film.

  Further, in the embodiment of the present invention, only the case where the object to be processed is linear is illustrated, but the present invention is not limited to this, and even in a film shape, a sheet shape, and a plate shape, they are stacked in a narrow chamber. Therefore, by using the present invention, an effect equivalent to that of the present embodiment can be obtained.

  Further, in the embodiment of the present invention, the case is illustrated only when the workpiece is vibrated. However, the present invention is not limited to this, and even when the workpiece is rotated and irregularly swung, the plasma active species is only present on a specific surface of the workpiece. Irradiation can be prevented, or the object to be processed can be prevented from coming into contact with the wall surface of the chamber for a long time, so that the same effect as the present invention can be obtained.

  Further, in the embodiment of the present invention, only the case where the vibration frequency is 5 Hz is exemplified, but if the vibration frequency is too small, the effect of suppressing heat conduction from the plasma to the object to be processed is thin, and if the vibration frequency is too large, Since the atmosphere is engulfed by convection due to vibration and the plasma density is lowered, the frequency is preferably about 0.1 Hz to 500 kHz. The same applies to the rotation frequency.

  In the embodiment of the present invention, the gas flow rate is increased only by opening and closing the gas stop valve. However, the present invention is not limited to this, and the gas flow rate can be increased by changing the set value of a flow meter or the like. Well, an effect equivalent to that of the present invention can be obtained.

  In the embodiment of the present invention, only the case where the distance between the electrodes is 2 mm is illustrated, but the present invention is not limited to this. If the distance between the electrodes is too large, it is difficult to generate plasma or it is easy to shift to arc plasma. More preferably, it is 4 mm or less.

  Moreover, in embodiment of this invention, although illustrated only when the distance from the end surface of the space between electrodes to the end surface of a to-be-processed object is 1 mm, it is not restricted to this. If the distance is too close, it is easily affected by the heat from the plasma, and if the distance is too far, the plasma density is lowered and the processing speed is remarkably lowered.

  Further, in the embodiment of the present invention, only the case of a processing gas having an inert gas concentration of about 93% has been exemplified, but if the amount of the inert gas is too small, the plasma density is significantly lowered. % Or more is good. Further, if there is too much inert gas, the chemical reactivity becomes poor and the processing speed is remarkably reduced. Therefore, the inert gas concentration is preferably about 99.9% or less.

In the embodiment of the present invention, the processing gas is exemplified only for the combination of the inert gas, the O ₂ gas, and the F-containing gas, but the present invention is not limited to this. Even when the processing gas is an inert gas, an O ₂ gas, and an N ₂ gas, the removal rate of the organic film can be increased by, for example, promoting the generation of ozone, thereby obtaining the same effect as the present invention. be able to. Further, as the F-containing gas, it has been illustrated only the CF ₄ gas is not limited _{thereto, F 2, CHF 3, HF} , CF 4, C 2 F 4, C 2 F 6, C 3 F 6, C 4 F _{6, C 3 F 8, C} 4 F 8, C 5 F 8, can provide the same effects in NF ₃ and SF ₆ gas.

Further, in the embodiment of the present invention, only the plasma processing as one process is illustrated, but the present invention is not limited to this. In the first step, the organic film on the surface of the object to be processed is removed with a gas containing at least an inert gas and O ₂ gas, and then exposed in a gas containing at least an inert gas and a reducing gas in the second step. Since the surface of the conducting wire oxidized during the removal of the organic film can be reduced by reducing the organic film, a further special effect is achieved. Examples of the reducing gas include H ₂ , NH ₃ , N ₂ , and CO gas.

  Moreover, in the embodiment of the present invention, only the case of solving by applying mechanical pressure as the unraveling mechanism is illustrated, but the present invention is not limited to this. Obtainable.

  Further, in the embodiment of the present invention, only caulking with the crimp terminal is illustrated. However, the present invention is not limited to this, and in the case of joining between solids and joining by mechanical pressure, an effect equivalent to that of the present invention is obtained. Obtainable.

  INDUSTRIAL APPLICABILITY The present invention can provide a plasma processing method and apparatus capable of removing coatings of all objects to be processed at high speed in batch processing of a plurality of objects to be processed that are adjacent and in contact with one or more places. Therefore, it is possible to provide a conductive wire that facilitates securing conduction with a desired metal member, and each conductive material, wiring component, electronic component, component terminal, printed circuit board, sheet substrate, film substrate, and particularly a plurality of objects to be processed. It can also be applied to uses such as etching, film formation, and surface treatment of the processing surface at high speed.

Sectional drawing of the plasma processing apparatus in 1st and 3rd embodiment of this invention The enlarged schematic diagram of the cross section of the to-be-processed object in 1st Embodiment of this invention Schematic external view of an object to be processed in the first embodiment of the present invention The cross-sectional enlarged view of the electrode vicinity in 1st, 2nd and 4th embodiment of this invention The figure which shows the SEM image which observed the cross section of the to-be-processed object in 1st Embodiment of this invention. Sectional drawing of the plasma processing apparatus in 2nd Embodiment of this invention. Upper sectional view of plasma processing apparatus in second embodiment of the present invention Sectional drawing of the plasma processing apparatus in 4th Embodiment of this invention. The cross-sectional enlarged view inside the disassembling unit 18 in the fourth embodiment of the present invention. A diagram showing a conventional plasma processing apparatus A diagram showing a conventional plasma processing apparatus The figure which shows the result at the time of using the conventional plasma processing apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Upper electrode 2 Lower electrode 3 Insulator chamber 4 Gas flow path 5 Process gas supply apparatus 6 Metal container 7 Gas supply port 8 Gas jet 9 High frequency power supply 10 To-be-processed object 11 Insulation block 12 Plasma 13 Vibration unit

Claims (38)

By providing a dielectric on at least one of the pair of electrodes and supplying high-frequency power while supplying a processing gas between the electrodes, plasma is generated between the electrodes under a pressure near atmospheric pressure, In the processing method, when exposing at least a part of the object to be processed to plasma without placing the object to be processed in a space formed between a pair of electrodes, the object to be processed is vibrated or rotated. A plasma processing method. By providing a dielectric on at least one of the pair of electrodes and supplying high-frequency power while supplying a processing gas between the electrodes, plasma is generated between the electrodes under a pressure near atmospheric pressure, In the processing method, the processing surface is irradiated with plasma-state gas from at least two directions without placing the processing object in a space formed between the pair of electrodes. The plasma processing method according to claim 1, wherein the object to be processed has a thread shape or a rod shape. 4. The plasma processing method according to claim 3, wherein a plurality of objects to be processed are stacked, bundled or relied on. The plasma processing method according to claim 1, wherein the object to be processed has a film shape, a sheet shape, or a plate shape. 6. The plasma processing method according to claim 5, wherein a plurality of workpieces are stacked. The plasma processing method according to claim 1, wherein the plasma gas is irradiated from a line direction of the workpiece. At least one direction is irradiated with a plasma state gas from the line direction of the object to be processed, and at least one direction is irradiated with a plasma state gas from a direction perpendicular to the line direction of the object to be processed. The plasma processing method according to claim 2. 6. The plasma processing method according to claim 3, wherein the object to be processed is a metal whose surface is partially and entirely covered with an organic film. The plasma processing method according to claim 9, wherein the organic film is a thermosetting resin. The plasma processing method according to claim 1, wherein the position of the object to be processed is moved with respect to the average flow velocity direction of the gas to be supplied. The plasma processing method according to claim 1, wherein the processing surface is processed while vibrating or rotating. The plasma processing method according to claim 12, wherein the vibration frequency is 0.1 Hz to 500 kHz. The plasma processing method according to claim 12, wherein the rotation frequency is 0.1 Hz to 500 kHz. 3. The plasma processing method according to claim 1, wherein the flow rate of the supplied gas is increased during the plasma processing or between the plasma processing and the plasma processing. The plasma processing method according to claim 15, wherein a contact area between adjacent objects to be processed is reduced by intermittently increasing a flow rate of a gas to be supplied. 16. The plasma processing method according to claim 15, wherein the gas flow rate is increased by a transient gas flow that flows at a moment when the gas supply is temporarily interrupted and the gas supply is resumed. The plasma processing method according to claim 15, wherein the gas supply is shut off and restarted through a gas stop valve. The plasma processing method according to claim 1, wherein the object to be processed is surrounded by at least two walls, and the two walls are opposed to each other. The plasma processing method according to claim 1 or 2, wherein a distance between the electrodes is 10 mm or less. The plasma processing method according to claim 1, wherein a distance between the electrodes is 4 mm or less. The plasma processing method according to claim 1 or 2, wherein the position where the end surface of the object to be processed is placed is separated by 0.5 mm or more from the end surface of the space formed between the electrodes. The plasma processing method according to claim 1 or 2, wherein the position where the end surface of the object to be processed is placed is 10 mm or less from the end surface of the space formed between the electrodes. 3. The plasma processing method according to claim 1, wherein the processing gas contains an inert gas at a ratio of 50% or more. The plasma processing method according to claim 1, wherein the processing gas contains an inert gas at a ratio of 99.9% or less. A first step of performing plasma processing using a gas containing an inert gas and an O ₂ gas and a second step of performing plasma processing using a gas containing an inert gas and a reducing gas are performed. The plasma processing method according to claim 1 or 2. 27. The plasma processing method according to claim 26, wherein the organic film on the surface of the workpiece is removed in the first step, and the metal element on the surface of the workpiece is reduced in the second step. Reducing gas _{is, H 2, NH 3, N} 2, and a plasma processing method of claim 26, wherein a is any of CO gas. 3. The plasma processing method according to claim 1, wherein the processing gas contains O ₂ gas and contains at least one of N ₂ and F element-containing gas. F element-containing gas is _{F 2, CHF 3, HF,} CF 4, C 2 F 4, C 2 F 6, C 3 F 6, C 4 F 6, C 3 F 8, C 4 F 8, C 5 F 8 The plasma processing method according to claim 21, wherein the plasma processing method is any one of NF ₃ and SF ₆ gases. A solid dielectric is provided on at least one of the pair of electrodes, and high-frequency power is supplied while supplying a processing gas between the electrodes, so that plasma is generated under a pressure near atmospheric pressure, and the plasma state gas is covered. Irradiate the object to be processed, and a plurality of objects to be processed that are in contact with each other at least at one point are placed on the surface to be processed without placing the object to be processed in the space between the pair of electrodes. The object to be processed and the metal member include a step of performing plasma treatment by irradiating and surrounding a plurality of objects to be processed with a metal member and bringing the object to be processed into contact with the metal member by applying mechanical pressure. Conductive wire characterized by conducting. 32. The conducting wire according to claim 31, wherein the step of applying mechanical pressure is a step of caulking. 32. The conducting wire according to claim 31, wherein the metal member is a crimp terminal. A solid dielectric is provided on at least one of the pair of electrodes, a high-frequency power source that can be connected to the electrode, and a gas supply device that can supply a processing gas between the electrodes are provided, via a gas flow path provided in a space formed between the electrodes. In the plasma processing apparatus capable of supplying the processing gas to the processing surface of the processing object, the plasma processing apparatus includes a wall made of at least two opposing insulators connected to the space formed between the electrodes. A plasma processing apparatus. A solid dielectric is provided on at least one of the pair of electrodes, a high-frequency power source that can be connected to the electrode, and a gas supply device that can supply a processing gas between the electrodes are provided, via a gas flow path provided in a space formed between the electrodes. In the plasma processing apparatus capable of supplying the processing gas to the entire processing surface of the processing object, the plasma processing apparatus includes a wall that is connected to a space formed between the electrodes and is made of at least two opposing insulators, A plasma processing apparatus comprising at least two gas flow paths. 36. The plasma processing apparatus according to claim 34 or 35, further comprising a moving mechanism capable of changing a position of an object to be processed relative to an electrode. The plasma processing apparatus according to claim 36, wherein the moving mechanism is capable of transmitting vibrations or transmitting rotation. 36. The plasma processing apparatus according to claim 34 or 35, further comprising a breaking mechanism capable of reducing a contact area between objects to be processed adjacent to each other.

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